Effect of pyrolysis temperature on characteristics and aromatic contaminants adsorption behavior of magnetic biochar derived from pyrolysis oil distillation residue.

PubMed

Li, Hao; Mahyoub, Samah Awadh Ali; Liao, Wenjie; Xia, Shuqian; Zhao, Hechuan; Guo, Mengya; Ma, Peisheng

2017-01-01

The magnetic biochars were easily fabricated by thermal pyrolysis of Fe(NO 3 ) 3 and distillation residue derived from rice straw pyrolysis oil at 400, 600 and 800°C. The effects of pyrolysis temperature on characteristics of magnetic biochars as well as adsorption capacity for aromatic contaminants (i.e., anisole, phenol and guaiacol) were investigated carefully. The degree of carbonization of magnetic biochars become higher as pyrolysis temperature increasing. The magnetic biochar reached the largest surface area and pore volume at the pyrolysis temperature of 600°C due to pores blocking in biochar during pyrolysis at 800°C. Based on batch adsorption experiments, the used adsorbent could be magnetically separated and the adsorption capacity of anisole on magnetic biochars was stronger than that of phenol and guaiacol. The properties of magnetic biochar, including surface area, pore volume, aromaticity, grapheme-like-structure and iron oxide (γ-Fe 2 O 3 ) particles, showed pronounced effects on the adsorption performance of aromatic contaminants. Copyright © 2016 Elsevier Ltd. All rights reserved.

Nutrient release and ammonium sorption by poultry litter and wood biochars in stormwater treatment.

PubMed

Tian, Jing; Miller, Valentina; Chiu, Pei C; Maresca, Julia A; Guo, Mingxin; Imhoff, Paul T

2016-05-15

The feasibility of using biochar as a filter medium in stormwater treatment facilities was evaluated with a focus on ammonium retention. Successive batch extractions and batch ammonium sorption experiments were conducted in both deionized (DI) water and artificial stormwater using poultry litter (PL) and hardwood (HW) biochars pyrolyzed at 400°C and 500°C. No measureable nitrogen leached from HW biochars except 0.07 μmol/g of org-N from 400°C HW biochar. PL biochar pyrolyzed at 400°C leached 120-127 μmol/g of nitrogen but only 7.1-8.6 μmol/g of nitrogen when pyrolyzed at 500°C. Ammonium sorption was significant for all biochars. At a typical ammonium concentration of 2mg/L in stormwater, the maximum sorption was 150 mg/kg for PL biochar pryolyzed at 400°C. In stormwater, ion competition (e.g. Ca(2+)) suppressed ammonium sorption compared to DI water. Surprisingly, ammonium sorption was negatively correlated to the BET surface area of the tested biochars, but increased linearly with cation exchange capacity. Cation exchange capacity was the primary mechanism controlling ammonium sorption and was enhanced by pyrolysis at 400°C, while BET surface area was enhanced by pyrolysis at 500°C. The optimal properties (BET surface area, CEC, etc.) of biochar as a sorbent are not fixed but depend on the target pollutant. Stormwater infiltration column experiments in sand with 10% biochar removed over 90% of ammonium with influent ammonium concentration of 2mg/L, compared to only 1.7% removal in a sand-only column, indicating that kinetic limitations on sorption were minor for the storm conditions studied. Hardwood and poultry litter biochar pyrolyzed at 500°C and presumably higher temperature may be viable filter media for stormwater treatment facilities, as they showed limited release of organic and inorganic nutrients and acceptable ammonium sorption. Copyright © 2016 Elsevier B.V. All rights reserved.

Molecular Structures and Sorption Mechanisms of Biochars as Heterogeneous Carbon Materials

NASA Astrophysics Data System (ADS)

Chen, Baoliang; Chen, Zaiming; Xiao, Xin; Fang, Qile

2015-04-01

Surface functional groups such as carboxyl play a vital role in the environmental applications of biochar as a soil amendment. However, the quantification of oxygen-containing groups on a biochar surface still lacks systematical investigation. An integrated method combining chemical and spectroscopic techniques was established to quantitatively identify the chemical states, dissociation constants (pKa), and contents of oxygen-containing groups on dairy manure-derived biochars prepared at 100-700 °C. The dissociation pH of carboxyl groups on the biochar surface covered a wide range of pH values (pH 2-11), due to the varied structural micro-environments and chemical states. For low temperature biochars (≤350 °C), carboxyl existed not only as hydrogen-bonded carboxyl and unbonded carboxyl groups but also formed esters at the surface of biochars. The esters consumed OH‒ via saponification in the alkaline pH region and enhanced the dissolution of organic matter from biochars. For high temperature biochars (≥500 °C), esters came from carboxyl were almost eliminated via carbonization (ester pyrolysis), while lactones were developed. The surface density of carboxyl groups on biochars decreased sharply with the increase of the biochar-producing temperature, but the total contents of the surface carboxyls for different biochars were comparable (with a difference < 3-fold) as a result of the expanded surface area at high pyrolytic temperatures. Understanding the wide pKa ranges and the abundant contents of carboxyl groups on biochars is a prerequisite to recognition of the multi-functional applications and biogeochemical cycling of biochars. A schematic diagram for the dissociation of acid/base groups on biochar surfaces and their related functions was depicted. The protonated biochars favor inorganic anion adsorption and ionizable organic chemical sorption, while the deprotonated biochars favor cationic nutrient retention, heavy metal immobilization, and the release of dissolved materials. For low temperature biochars (i.e., DM100, DM250 and DM350), the acid/base group dissociation directly controls the pH buffering properties of biochars. The resulting surface charges regulate biochars in nutrient retention, sorption/immobilization of hazardous pollutants and biochar particle dispersing properties. Meanwhile, dissociation of acid/base groups affects carbon and silica biogeochemical cycling by regulating the release of organic matter from the cleavage of esters and dissolution of the Si-containing minerals. For high temperature biochars (i.e., DM500 and DM700), the effect of acid/base dissociation on organic matter dissolution is eliminated, but other functions are similar. CGs are the major acid/base groups on biochar surfaces. In field applications, such abundant CGs are worthy of concern in terms of multiple functions of biochars, such as soil pH adjustment, soil nutrient retention, and toxic metals immobilization.

Structural characteristics of biochar-graphene nanosheet composites and their adsorption performance for phthalic acid esters

NASA Astrophysics Data System (ADS)

Ghaffar, Abdul; Zhu, Xiaoying; Chen, Baoliang

2017-04-01

The nonuniform and unhomogenous structure of biochar including defects could affect the adsorption performance of biochars. Biochar and graphene nanosheet (GNS) composites (BG) were prepared by simple dip coating method following thermal route of bamboo wood biomass at three different temperatures (300, 500, 700°C), in addition to biochars. The morphology and structural composition of biochars and BG composites were examined by scanning electron microscopy, transmission electron microscopy, Brunauer-Emmet-Teller surface area with N2 and CO2, Raman spectroscopy, Fourier Transformed Infrared spectroscopy, X-ray Photoelectron spectroscopy, Thermogravimetric analysis and CHN elemental analysis. It was found that GNS ( 1µm, 0.1% mass) provided higher thermal stability, porous structure, and relatively higher surface area (N2 and CO2), to BG composites. BG composites portrayed the existence of GNS bearing cavities and evidently increased the graphitic structure. The adsorption capabilities of biochars and BG composites towards dimethyl phthalate (DMP), diethyl phthalate (DEP), and dibutyl phthalate (DBP) as model phthalic acid esters (PAEs) were examined by batch sorption technique. The BG composites exhibited the increased adsorption capacity comparatively to biochars. The aromatic sheets of biochars and GNS on biochars dominated the π-π EDA (electron donor-acceptor) interaction for ring structure of DMP molecule in addition to pore-diffusion mechanism, whereas adsorption of DBP was attributed to hydrophobicity. Our results suggest that surface composition and morphology of biochars can be regulated with GNS and may enhance their adsorption capacity, thus could be considered for effective environmental remediation of various organic contaminants.

Biochar produced from biosolids using a single-mode microwave: Characterisation and its potential for phosphorus removal.

PubMed

Antunes, Elsa; Schumann, James; Brodie, Graham; Jacob, Mohan V; Schneider, Philip A

2017-07-01

The amount of biosolids increases every year, and social and environmental concerns are also rising due to heavy metals and pathogen contamination. Even though biosolids are considered as a waste material, they could be used as a precursor in several applications, especially in agriculture due to the presence of essential nutrients. Microwave assisted pyrolysis (MWAP) is a promising technology to safely manage biosolids, while producing value-added products, such as biochar, that can be used to improve soil fertility. This study examined the impact of pyrolysis temperature between 300 °C and 800 °C on the chemical and physical properties of biochar obtained from biosolids via MWAP. Preliminary phosphorus adsorption tests were carried out with the biochar produced from biosolids. This research demonstrated that pyrolysis temperature affects biochar specific surface area, ash and volatiles content, but does not impact heavily on the pH, chemical composition and crystalline phases of the resultant biochar. Biochar yield decreases as the pyrolysis temperature increases. Phosphorus adsorption capacity of biochar was approximately around 15 mg/g of biochar. Biochar resulting from MWAP is a potential candidate for land application with an important role in water and nutrient retention, due to the high surface area. Copyright © 2017 Elsevier Ltd. All rights reserved.

Novel use of magnetic biochars for the remediation of soils contaminated by contaminants of emerging concerns (CECs)

NASA Astrophysics Data System (ADS)

Sani, Badruddeen; Mrozik, Wojciech; Werner, David

2016-04-01

The advantage of using magnetic biochar over nonmagnetic biochar in amendments of contaminated soils is in the fact that the former can be easily removed from the soil matrix whenever the need arises, using simple principles of magnetism. In this study, magnetic biochar was produced using a simple co-precipitation technique. The resulting composite has about 33% (w/w) magnetic iron oxides, the presence of which resulted in modification of the biochar's surface characteristics such as BET surface area, porosity and point of zero charge. Modifications in these properties will most likely alter the CEC sorption properties of the biochar, hence the necessity for the proper evaluation of the possible trade off that exist between the need for magnetisation and altered sorption characteristics of the biochar. To achieve this, bottle point sorption experiments in aqueous solutions were conducted using activated and non-activated biochars in magnetic and nonmagnetic forms as sorbents and two pharmaceuticals -ibuprofen and diclofenac- as representative CECs. Sorption isotherms were evaluated and the data was fitted to Langmuir, Freundlich, Redlich-Peterson, Dubinin-Ashtakov and Polanyi-Dubinin-Manes isotherm models. Removal efficiencies and sorption capacities correlated well with the effective mass of pristine biochar used, therefore the sorption characteristics of both magnetic and nonmagnetic biochars are not detrimentally affected by the magnetite impregnation. Biochars in activated form show superior sorption capacities due to amplified surface area and better developed pores. Also, non-activated biochars needed to be used in higher amounts to achieve considerable level of CEC removal, thus they are more easily exhausted. Sorption was observed to decrease with a corresponding increase in solution pH. This suggests that sorption is favoured within the acidic pH range when the surfaces of the sorbents have net positive charge and the sorbates are in their neutral forms.

Fabrication of magnetic biochar as a treatment medium for As(V) via pyrolysis of FeCl3-pretreated spent coffee ground.

PubMed

Cho, Dong-Wan; Yoon, Kwangsuk; Kwon, Eilhann E; Biswas, Jayanta Kumar; Song, Hocheol

2017-10-01

This study investigated the preparation of magnetic biochar from N 2 - and CO 2 -assisted pyrolysis of spent coffee ground (SCG) for use as an adsorption medium for As(V), and the effects of FeCl 3 pretreatment of SCG on the material properties and adsorption capability of the produced biochar. Pyrolysis of FeCl 3 -pretreated SCG in CO 2 atmosphere produced highly porous biochar with its surface area ∼70 times greater than that produced in N 2 condition. However, despite the small surface area, biochar produced in N 2 showed greater As(V) adsorption capability. X-ray diffraction and X-ray photoelectron spectrometer analyses identified Fe 3 C and Fe 3 O 4 as dominant mineral phases in N 2 and CO 2 conditions, with the former being much more adsorptive toward As(V). The overall results suggest functional biochar can be facilely fabricated by necessary pretreatment to expand the applicability of biochar for specific purposes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Characterization and 2D structural model of corn straw and poplar leaf biochars.

PubMed

Zhao, Nan; Lv, YiZhong; Yang, XiXiang; Huang, Feng; Yang, JianWen

2017-12-22

The integrated experimental methods were used to analyze the physicochemical properties and structural characteristics and to build the 2D structural model of two kinds of biochars. Corn straw and poplar leaf biochars were gained by pyrolysing the raw materials slowly in a furnace at 300, 500, and 700 °C under oxygen-deficient conditions. Scanning electron microscope was applied to observe the surface morphology of the biochars. High temperatures destroyed the pore structures of the biochars, forming a particle mixture of varying sizes. The ash content, yield, pH, and surface area were also observed to describe the biochars' properties. The yield decreases as the pyrolysis temperature increases. The biochars are neutral to alkaline. The biggest surface area is 251.11 m 2 /g for 700 °C corn straw biochar. Elemental analysis, infrared microspectroscopy, solid-state C-13 NMR spectroscopy, and pyrolysis gas chromatography-mass spectrometry (Py-GC-MS) were also used to study the structural characteristics and build the 2D structural models of biochars. The C content in the corn straw and poplar leaf biochars increases with the increase of the pyrolysis temperature. A higher pyrolysis temperature makes the aryl carbon increase, and C=O, OH, and aliphatic hydrocarbon content decrease in the IR spectra. Solid-state C-13 NMR spectra show that a higher pyrolysis temperature makes the alkyl carbon and alkoxy carbon decrease and the aryl carbon increase. The results of IR microspectra and solid-state C-13 NMR spectra reveal that some noticeable differences exist in these two kinds of biochars and in the same type of biochar but under different pyrolysis temperatures. The conceptual elemental compositions of 500 °C corn straw and poplar leaf biochars are C 61 H 33 NO 13 and C 59 H 41 N 3 O 12 , respectively. Significant differences exist in the SEM images, physicochemical properties, and structural characteristics of corn straw and poplar leaf biochars.

Biochar: sustainable and versatile

USDA-ARS?s Scientific Manuscript database

Biochar is a term that describes any charcoal that comes from biomass. It is a renewable, microporous carbon-rich product that also contains nitrogen, hydrogen, oxygen, and ash. Several varieties of biochar are very porous with irregular surface area. The pore size and distribution of a given biocha...

Biochar modification to enhance sorption of inorganics from water.

PubMed

Sizmur, Tom; Fresno, Teresa; Akgül, Gökçen; Frost, Harrison; Moreno-Jiménez, Eduardo

2017-12-01

Biochar can be used as a sorbent to remove inorganic pollutants from water but the efficiency of sorption can be improved by activation or modification. This review evaluates various methods to increase the sorption efficiency of biochar including activation with steam, acids and bases and the production of biochar-based composites with metal oxides, carbonaceous materials, clays, organic compounds, and biofilms. We describe the approaches, and explain how each modification alters the sorption capacity. Physical and chemical activation enhances the surface area or functionality of biochar, whereas modification to produce biochar-based composites uses the biochar as a scaffold to embed new materials to create surfaces with novel surface properties upon which inorganic pollutants can sorb. Many of these approaches enhance the retention of a wide range of inorganic pollutants in waters, but here we provide a comparative assessment for Cd 2+ , Cu 2+ , Hg 2+ , Pb 2+ , Zn 2+ , NH 4 + , NO 3 - , PO 4 3- , CrO 4 2- and AsO 4 3- . Copyright © 2017 Elsevier Ltd. All rights reserved.

Date palm waste-derived biochar composites with silica and zeolite: synthesis, characterization and implication for carbon stability and recalcitrant potential.

PubMed

Ahmad, Munir; Ahmad, Mahtab; Usman, Adel R A; Al-Faraj, Abdullah S; Abduljabbar, Adel; Ok, Yong Sik; Al-Wabel, Mohammad I

2017-03-23

Engineered organo-mineral composites were synthesized from date palm waste biochar and silica or zeolite via mechanochemical treatments. Date palm tree rachis (leaves) waste biomass was pre-treated with silica or zeolite minerals via ball milling and sonication prior to pyrolysis at 600 °C. The resultant organo-mineral composites and pristine materials were characterized using X-ray diffraction, thermogravimetric-differential thermal (TG-DTA), Fourier transform infrared, scanning electron microscope analyses and surface area and porosity analyzer to investigate the variations in physiochemical and structural characteristics. Compared to the resultant composites derived from non-milled date palm biomass, ball milling increased surface area, while decreased crystallinity index and effective particle size of the biochar composites. Silica composited biochars were located near origin in the van Krevelen diagram indicating lowest H/C and O/C molar ratios, thus suggesting higher aromaticity and lower polarity compared to other biochars. TGA thermograms indicated highest thermal stability of silica composited biochars. Ash and moisture corrected TGA thermograms were used to calculate recalcitrance index (R 50 ) of the materials, which speculated high degradability of biomass (R 50  < 0.4), minimal degradability of biochars and zeolite composited biochars (0.5 < R 50  < 0.7) and high recalcitrant nature of silica composited biochars (R 50  > 0.7). Silica composited biochars exhibited highest carbon sequestration potential (64.17-95.59%) compared to other biochars. Highest recalcitrance and carbon sequestration potential of silica composited biochars may be attributed to changes in structural arrangements in the silica-biochar complex. Encapsulations of biochar particles with amorphous silica via Si-C bonding may have prevented thermal degradation, subsequently increasing recalcitrance potential of silica composited biochars.

Chloropicrin emission reduction by soil amendment with biochar

USDA-ARS?s Scientific Manuscript database

Biochar is the carbon-enriched and porous material produced by heating organic material under conditions of limited or no oxygen. As biochar has a large surface area and strong sorption capacity, it can enhance the sequestration of organic contaminants such as pesticides in soil. Chloropicrin (CP) i...

Ammonia adsorption capacity of biomass and animal-manure derived biochars

USDA-ARS?s Scientific Manuscript database

The objective of this research was to characterize and investigate ammonia and hydrogen sulfide gas adsorption capacities of low- and high-temperature biochars made from wood shavings and chicken litter. The biochar samples were activated with steam or phosphoric acid. The specific surface areas and...

Biochar as possible long-term soil amendment for phytostabilisation of TE-contaminated soils.

PubMed

Bopp, Charlotte; Christl, Iso; Schulin, Rainer; Evangelou, Michael W H

2016-09-01

Soils contaminated by trace elements (TEs) pose a high risk to their surrounding areas as TEs can spread by wind and water erosion or leaching. A possible option to reduce TE transfer from these sites is phytostabilisation. It is a long-term and cost-effective rehabilitation strategy which aims at immobilising TEs within the soil by vegetation cover and amendment application. One possible amendment is biochar. It is charred organic matter which has been shown to immobilise metals due to its high surface area and alkaline pH. Doubts have been expressed about the longevity of this immobilising effect as it could dissipate once the carbonates in the biochar have dissolved. Therefore, in a pot experiment, we determined plant metal uptake by ryegrass (Lolium perenne) from three TE-contaminated soils treated with two biochars, which differed only in their pH (acidic, 2.80; alkaline, 9.33) and carbonate (0.17 and 7.3 %) content. Root biomass was increased by the application of the alkaline biochar due to the decrease in TE toxicity. Zinc and Cu bioavailability and plant uptake were equally reduced by both biochars, showing that surface area plays an important role in metal immobilisation. Biochar could serve as a long-term amendment for TE immobilisation even after its alkalinity effect has dissipated.

Heavy metal removal from aqueous solutions using engineered magnetic biochars derived from waste marine macro-algal biomass.

PubMed

Son, Eun-Bi; Poo, Kyung-Min; Chang, Jae-Soo; Chae, Kyu-Jung

2018-02-15

Despite the excellent sorption ability of biochar for heavy metals, it is difficult to separate and reuse after adsorption when applied to wastewater treatment process. To overcome these drawbacks, we developed an engineered magnetic biochar by pyrolyzing waste marine macro-algae as a feedstock, and we doped iron oxide particles (e.g., magnetite, maghemite) to impart magnetism. The physicochemical characteristics and adsorption properties of the biochar were evaluated. When compared to conventional pinewood sawdust biochar, the waste marine algae-based magnetic biochar exhibited a greater potential to remove heavy metals despite having a lower surface area (0.97m 2 /g for kelp magnetic biochar and 63.33m 2 /g for hijikia magnetic biochar). Although magnetic biochar could be effectively separated from the solution, however, the magnetization of the biochar partially reduced its heavy metal adsorption efficiency due to the biochar's surface pores becoming plugged with iron oxide particles. Therefore, it is vital to determine the optimum amount of iron doping that maximizes the biochar's separation without sacrificing its heavy metal adsorption efficiency. The optimum concentration of the iron loading solution for the magnetic biochar was determined to be 0.025-0.05mol/L. The magnetic biochar's heavy metal adsorption capability is considerably higher than that of other types of biochar reported previously. Further, it demonstrated a high selectivity for copper, showing two-fold greater removal (69.37mg/g for kelp magnetic biochar and 63.52mg/g for hijikia magnetic biochar) than zinc and cadmium. This high heavy metal removal performance can likely be attributed to the abundant presence of various oxygen-containing functional groups (COOH and OH) on the magnetic biochar, which serve as potential adsorption sites for heavy metals. The unique features of its high heavy metal removal performance and easy separation suggest that the magnetic algae biochar can potentially be applied in diverse areas that require biosorbents for pollutant removal. Copyright © 2017 Elsevier B.V. All rights reserved.

Peroxide-assisted microwave activation of pyrolysis char for adsorption of dyes from wastewater.

PubMed

Nair, Vaishakh; Vinu, R

2016-09-01

In this study, mesoporous activated biochar with high surface area and controlled pore size was prepared from char obtained as a by-product of pyrolysis of Prosopis juliflora biomass. The activation was carried out by a simple process that involved H2O2 treatment followed by microwave pyrolysis. H2O2 impregnation time and microwave power were optimized to obtain biochar with high specific surface area and high adsorption capacity for commercial dyes such as Remazol Brilliant Blue and Methylene Blue. Adsorption parameters such as initial pH of the dye solution and adsorbent dosage were also optimized. Pore size distribution, surface morphology and elemental composition of activated biochar were thoroughly characterized. H2O2 impregnation time of 24h and microwave power of 600W produced nanostructured biochar with narrow and deep pores of 357m(2)g(-1) specific surface area. Langmuir and Langmuir-Freundlich isotherms described the adsorption equilibrium, while pseudo second order model described the kinetics of adsorption. Copyright © 2016 Elsevier Ltd. All rights reserved.

Fugitive gas adsorption capacity of biomass and animal-manure derived biochars

USDA-ARS?s Scientific Manuscript database

This research characterized and investigated ammonia and hydrogen sulfide gas adsorption capacities of low- and high-temperature biochars made from wood shavings and chicken litter. The biochar samples were activated with steam or phosphoric acid. The specific surface areas and pore volumes of the a...

Influence of the biochar application for the recovery of Spanish mine area

NASA Astrophysics Data System (ADS)

Gascó Guerrero, Gabriel; Álvarez Calvo, María Luisa; Paz-Ferreiro, Jorge; César Arranz, Julio; Saa, Antonio; Méndez, Ana

2017-04-01

The use of organic amendment areas has been a very common technique for the restoration of land affected by mining activities. Recent years, the use of biochar for the treatment of metal-contaminated soils can be an adequate strategy due to biochar can decrease the trace metal mobility. This effect depends on biochar properties as cation exchange capacity, surface area or pH which are highly related with the raw material and pyrolysis conditions. The aim of this work is to study soil response after the use of 4 different biochars in the treatment of different soil samples collected in the Rio Tinto area (Spain) which is the main Spanish Cu mine since 15 years ago. For this purpose, biochars were added to the different soils at a dosage of 8 wt%, and samples were incubated during 6 months. After this period, the influence of biochar on trace metal mobility was assessed. The study was completed determining microbial biomass, soil respiration and several enzymes activities to study the biochar influence on soil biochemical activities. We are very grateful to Ministerio de Economía y Competitividad (Spain) for financial support under Project CGL2014-58322-R.

Capacity and mechanisms of ammonium and cadmium sorption on different wetland-plant derived biochars.

PubMed

Cui, Xiaoqiang; Hao, Hulin; Zhang, Changkuan; He, Zhenli; Yang, Xiaoe

2016-01-01

The objective of this study was to investigate the relationship between Cd(2+)/NH4(+) sorption and physicochemical properties of biochars produced from different wetland plants. Biochars from six species of wetland plants (i.e., Canna indica, Pennisetum purpureum Schum, Thalia dealbata, Zizania caduciflora, Phragmites australis and Vetiveria zizanioides) were obtained at 500°C and characterized, and their sorption for ammonium and cadmium was determined. There were significant differences in elemental composition, functional groups and specific surface area among the biochars derived from different wetland plant species. Sorption of ammonium and cadmium on the biochars could be described by a pseudo second order kinetic model, and the simple Langmuir model fits the isotherm data better than the Freundlich or Temkin model. The C. indica derived biochar had the largest sorption capacity for NH4(+) and Cd(2+), with a maximum sorption of 13.35 and 125.8mgg(-1), respectively. P. purpureum Schum derived biochar had a similar maximum sorption (119.3mgg(-1)) for Cd(2+). Ammonium sorption was mainly controlled by cation exchange, surface complexation with oxygen-containing functional groups and the formation of magnesium ammonium phosphate compounds, whereas for Cd(2+) sorption, the formation of cadmium phosphate precipitates, cation exchange and binding to oxygen-containing groups were the major possible mechanisms. In addition, the sorption of ammonium and cadmium was not affected by surface area and microporosity of the biochars. Copyright © 2015 Elsevier B.V. All rights reserved.

Natural oxidation of a temperature series of biochars: opposite effect on the sorption of aromatic cationic herbicides.

PubMed

Shi, Kaishun; Xie, Ya; Qiu, Yuping

2015-04-01

The natural oxidation of biochar in the environment has been widely observed. However, its influence on the sorption of organic contaminants remains poorly understood. In the present study, a series of wood-based biochars prepared between 300 and 600°C (referred to as BC300-BC600) was abiotically incubated for one year to examine the aging effect of the temperature series of biochars on their sorption of aromatic cationic herbicides (ACHs, paraquat and diquat) as well as a nonpolar reference adsorbate (naphthalene). One year of oxidation showed no obvious effect on the surface area, but distinct increases in the O/C elemental ratio, density of the surface groups and cation exchange capacity (CEC) were observed. Therefore, these properties were significantly affected by the charring temperature. After incubation, high-temperature biochars (BC500 and BC600) displayed a 14.1-36.3% decrease in the sorption (qm) of ACHs. The alteration of their sorption tendency was similar to the reduced sorption of naphthalene on oxidized biochars, in which the increased surface groups lowered the surface area accessible to adsorbates because of blockage by adsorbed water molecule clusters. Conversely, a pronounced increase of ACHs sorption by 121.7-201.1% on the low-temperature biochar (BC300) was observed, presumably due to the increase of CEC values after oxidation. This result was further demonstrated by a significant linear relationship between the paraquat sorption (qm) and CEC values (R(2)=0.9895) of oxidized biochars. Interestingly, one year of oxidation simultaneously resulted in an enhanced sorption of paraquat and a reduced sorption of diquat on BC400, which indicated that the oxidation-induced sorption change of ACHs is a complex function of changes in the surface properties of the biochars as well as the molecular structure of the solute. Copyright © 2015 Elsevier Inc. All rights reserved.

Characterization of narrow micropores in almond shell biochars by nitrogen, carbon dioxide, and hydrogen adsorption

USDA-ARS?s Scientific Manuscript database

Characterization of biochars usually includes surface area and pore volume determination by nitrogen adsorption. In this study, we show that there is a substantial pore volume in biochars created via slow pyrolysis from low- and high-ash almond shells that cannot be characterized in this fashion due...

Production of biochar from olive mill solid waste for heavy metal removal.

PubMed

Abdelhadi, Samya O; Dosoretz, Carlos G; Rytwo, Giora; Gerchman, Yoram; Azaizeh, Hassan

2017-11-01

Commercial activated carbon (CAC) and biochar are useful adsorbents for removing heavy metals (HM) from water, but their production is costly. Biochar production from olive solid waste from two olive cultivars (Picual and Souri) and two oil production process (two- or three-phase) and two temperatures (350 and 450°C) was tested. The biochar yield was 24-35% of the biomass, with a surface area of 1.65-8.12m 2 g -1 , as compared to 1100m 2 g -1 for CAC. Picual residue from the two-phase milling technique, pyrolysed at 350°C, had the best cumulative removal capacity for Cu +2 , Pb +2 , Cd +2 , Ni +2 and Zn +2 with more than 85% compared to other biochar types and CAC. These results suggest that surface area cannot be used as a sole predictor of HM removal capacity. FTIR analysis revealed the presence of different functional groups in the different biochar types, which may be related to the differences in absorbing capacities. Copyright © 2017 Elsevier Ltd. All rights reserved.

Adsorption Behavior of Selective Recognition Functionalized Biochar to Cd(II) in Wastewater

PubMed Central

Zhang, Shiqiu; Yang, Xue; Liu, Le; Ju, Meiting; Zheng, Kui

2018-01-01

Biochar is an excellent absorbent for most heavy metal ions and organic pollutants with high specific surface area, strong aperture structure, high stability, higher cation exchange capacity and rich surface functional groups. To improve the selective adsorption capacity of biochar to designated heavy metal ions, biochar prepared by agricultural waste is modified via Ionic-Imprinted Technique. Fourier transform infrared (FT-IR) spectra analysis and X-ray photoelectron spectroscopy (XPS) analysis of imprinted biochar (IB) indicate that 3-Mercaptopropyltrimethoxysilane is grafted on biochar surface through Si–O–Si bonds. The results of adsorption experiments indicate that the suitable pH range is about 3.0–8.0, the dosage is 2.0 g·L−1, and the adsorption equilibrium is reached within 960 min. In addition, the data match pseudo-second-order kinetic model and Langmuir model well. The computation results of adsorption thermodynamics and stoichiometric displacement theory of adsorption (SDT-A) prove that the adsorption process is spontaneous and endothermic. Finally, IB possesses a higher selectivity adsorption to Cd(II) and a better reuse capacity. The functionalized biochar could solidify designated ions stably. PMID:29443954

Characterization of leaf waste based biochar for cost effective hydrogen sulphide removal from biogas.

PubMed

Sahota, Shivali; Vijay, Virendra Kumar; Subbarao, P M V; Chandra, Ram; Ghosh, Pooja; Shah, Goldy; Kapoor, Rimika; Vijay, Vandit; Koutu, Vaibhav; Thakur, Indu Shekhar

2018-02-01

Installation of decentralized units for biogas production along with indigenous upgradation systems can be an effective approach to meet growing energy demands of the rural population. Therefore, readily available leaf waste was used to prepare biochar at different temperatures and employed for H 2 S removal from biogas produced via anaerobic digestion plant. It is found that biochar prepared via carbonization of leaf waste at 400 °C effectively removes 84.2% H 2 S (from 1254 ppm to 201 ppm) from raw biogas for 25 min in a continuous adsorption tower. Subsequently, leaf waste biochar compositional, textural and morphological properties before and after H 2 S adsorption have been analyzed using proximate analysis, CHNS, BET surface area, FTIR, XRD, and SEM-EDX. It is found that BET surface area, pore size, and textural properties of leaf waste biochar plays a crucial role in H 2 S removal from the biogas. Copyright © 2017 Elsevier Ltd. All rights reserved.

Chemically modified biochar produced from conocarpus waste increases NO3 removal from aqueous solutions.

PubMed

Usman, Adel R A; Ahmad, Mahtab; El-Mahrouky, Mohamed; Al-Omran, Abdulrasoul; Ok, Yong Sik; Sallam, Abdelazeem Sh; El-Naggar, Ahmed H; Al-Wabel, Mohammad I

2016-04-01

Biochar has emerged as a universal sorbent for the removal of contaminants from water and soil. However, its efficiency is lower than that of commercially available sorbents. Engineering biochar by chemical modification may improve its sorption efficiency. In this study, conocarpus green waste was chemically modified with magnesium and iron oxides and then subjected to thermal pyrolysis to produce biochar. These chemically modified biochars were tested for NO3 removal efficiency from aqueous solutions in batch sorption isothermal and kinetic experiments. The results revealed that MgO-biochar outperformed other biochars with a maximum NO3 sorption capacity of 45.36 mmol kg(-1) predicted by the Langmuir sorption model. The kinetics data were well described by the Type 1 pseudo-second-order model, indicating chemisorption as the dominating mechanism of NO3 sorption onto biochars. Greater efficiency of MgO-biochar was related to its high specific surface area (391.8 m(2) g(-1)) and formation of strong ionic complexes with NO3. At an initial pH of 2, more than 89 % NO3 removal efficiency was observed for all of the biochars. We conclude that chemical modification can alter the surface chemistry of biochar, thereby leading to enhanced sorption capacity compared with simple biochar.

Production and characterization of carbonized sorbent products optimized for anionic contaminants

NASA Astrophysics Data System (ADS)

Viglasova, Eva; Fristak, Vladimir; Galambos, Michal; Hood-Nowotny, Rebecca; Soja, Gerhard

2017-04-01

Processing conditions, production methods and feedstock characteristics have been shown to affect the final sorption properties of biochar-based sorbents that have been produced in pyrolysis reactors. The content of O-containing carboxyl, phenolic and hydroxyl functional groups on the biochar surfaces plays a crucial role in sorption chemistry of hazardous materials. The sorption process can be affected by the presence of non-carbonized fractions in biochar matter as well. All these characteristics indicate that biochar shows good potential as a new tool in removal and separation technologies of various pollutants from waste water or contaminated soils. The sorption potential of wood-based biochars for cationic forms of heavy metals has been studied intensively and has already led to successful pilot applications in the field. However, anionic compounds (e.g. phosphate, nitrate, sulphate, As-, Cr-compounds) do not sorb well to unmodified biochar and need specific surface modification of biochar. Based on this fact, we try to obtain data about the sorptive separation of anionic forms of various contaminants from model aqueous solutions by different types of biochar-derived sorbents, or mineral-enriched biochar-derived sorbents. An important part of this research is the assesment of the effects of varying process parameters during biomass carbonisation, the role of biomass feedstock and pre-and/or post-treatment of the biochars onto sorption processes. We specify the most appropriate application strategies with biochar for remediation purposes of waste water or contaminated waters with elevated toxic metal concentrations that might compromise the quality of surface waters. The main aim of research is the preparation of modified biochar sorbent, the characterization of its surface and the investigation about new possibilities of modified biochar sorbent applications for sorption of various contaminants, mainly their anionic forms (e.g. phosphates, nitrates, arsenates). Modification of bamboo-based biochar with clay minerals, the preparation of its composites, could increase the surface area of bamboo-based biochar from 3 to 5 times. Other ways of modification e.g. by using FeCl3 ṡ 6H2O caused a significant increase of sorption ability for anionic forms

The role of tailored biochar in increasing plant growth, and reducing bioavailability, phytotoxicity, and uptake of heavy metals in contaminated soil.

PubMed

Mohamed, Badr A; Ellis, Naoko; Kim, Chang Soo; Bi, Xiaotao

2017-11-01

Microwave-assisted catalytic pyrolysis was investigated using K 3 PO 4 and clinoptilolite to enhance biochar sorption affinity for heavy metals. The performance of resulting biochar samples was characterized through their effects on plant growth, bioavailability, phytotoxicity, and uptake of heavy metals in a sandy soil contaminated with Pb, Ni, and Co. The produced biochars have high cation-exchange capacity (CEC) and surface area, and rich in plant nutrients, which not only reduced heavy metals (Pb, Ni, and Co), bioavailability and phytotoxicity, but also increased plant growth rate by up to 145%. The effectiveness of biochar in terms of reduced phytotoxicity and plant uptake of heavy metals was further improved by mixing K 3 PO 4 and clinoptilolite with biomass through microwave pyrolysis. This may be due to the predominance of different mechanisms as 10KP/10Clino biochar has the highest micropore surface area (405 m 2 /g), high concentrations of K (206 g/kg), Ca (26.5 g/kg), Mg (6.2 g/kg) and Fe (11.9 g/kg) for ion-exchange and high phosphorus content (79.8 g/kg) for forming insoluble compounds with heavy metals. The largest wheat shoot length (143 mm) and lowest extracted amounts of Pb (107 mg/kg), Ni (2.4 mg/kg) and Co (63.9 mg/kg) were also obtained by using 10KP/10Clino biochar at 2 wt% load; while the smallest shoot length (68 mm) and highest extracted amounts of heavy metals (Pb 408 mg/kg, Ni 15 mg/kg and Co 148 mg/kg) for the samples treated with biochars were observed for soils mixed with 1 wt% 10Clino biochar. Strong negative correlations were also observed between biochar micropore surface area, CEC and the extracted amounts of heavy metals. Microwave-assisted catalytic pyrolysis of biomass has a great potential for producing biochar with high sorption affinity for heavy metals and rich nutrient contents using properly selected catalysts/additives that can increase microwave heating rate and improve biochar and bio-oil properties. Copyright © 2017 Elsevier Ltd. All rights reserved.

Influence of pyrolysis temperature on lead immobilization by chemically modified coconut fiber-derived biochars in aqueous environments.

PubMed

Wu, Weidong; Li, Jianhong; Niazi, Nabeel Khan; Müller, Karin; Chu, Yingchao; Zhang, Lingling; Yuan, Guodong; Lu, Kouping; Song, Zhaoliang; Wang, Hailong

2016-11-01

Biochar has received widespread attention as an eco-friendly and efficient material for immobilization of toxic heavy metals in aqueous environments. In the present study, three types of coconut fiber-derived biochars were obtained by pyrolyzing at three temperatures, i.e., 300, 500, and 700 °C. In addition, nine types of biochars were prepared by chemical modification with ammonia, hydrogen peroxide, and nitric acid, respectively, which were used to investigate changes in physico-chemical properties by inter alia, Fourier transformation infrared spectrophotometry (FTIR), scanning electron microscope (SEM), and BET specific surface area analysis. Batch sorption experiments were carried out to determine the sorption capacity of the biochars for lead (Pb) in aqueous solutions. Results showed that the cation exchange capacity of biochar pyrolyzed at 300 °C and modified with nitric acid increased threefold compared to the control. Loosely corrugated carbon surface and uneven carbon surface of the biochar pyrolyzed at 300 °C were produced during ammonia and nitric acid modifications. Removal rate of Pb by the coconut biochar pyrolyzed at 300 °C and modified with ammonia was increased from 71.8 to 99.6 % compared to the untreated biochar in aqueous solutions containing 100 mg L -1 Pb. However, chemical modification did not enhance adsorption of Pb of the biochars pyrolyzed at higher temperatures (e.g., 500 or 700 °C), indicating that resistance of biochars to chemical treatment increased with pyrolysis temperature.

Methylene Blue Removal by Biochars from Food Industry By-Products

NASA Astrophysics Data System (ADS)

Orfanos, Alexis; Manariotis, Ioannis D.; Karapanagioti, Hrissi K.

2016-04-01

Biomass produced by food industries is mainly used as feedstock or in composting. In recent years, considerable research effort has been focused on the production of biochar under oxygen-limited conditions from carbon-rich biomass, such as food industry by-products, as mitigation measure for global warming once it is used as a soil amendment. The present study presents the findings of an experimental work, which investigated the use of different biochars for the removal of methylene blue (MB) from aqueous solutions. Biochars were produced from malt spent rootlets (MSR) from brewering and espresso coffee residue from coffee shops. MSR was pyrolyzed at temperatures of 300, 400, 500, 750, 850, and 900oC and the coffee residue was pyrolyzed at 850oC. The charring process was performed under limited-oxygen conditions using specialized containers. The surface area and the porosity of the materials were determined. Batch experiments were conducted in order to evaluate the sorption capacity of the above materials, and samples were agitated for 24 h at 25oC, at an optimum pH of about 7. Kinetic analysis was conducted over a period of 24 h, and isotherm studies were also constructed. The surface area of biochar produced from MSR and the MB removal were considerably increased at pyrolysis temperatures higher than 500oC. At 850oC, the maximum surface area value (300 m2 g-1) was observed, and the MB sorption capacity was 99 mg g-1. Based on the kinetic experimental data, sorption capacities at 120 min were over 58% of their equilibrium values for the biochars used. The maximum MB sorption capacity, based on the isotherm data, was 130 mg g-1, for the two biochars employed.

Adsorption Characteristics of Pb(2+) onto Wine Lees-Derived Biochar.

PubMed

Zhu, Qihong; Wu, Jun; Wang, Lilin; Yang, Gang; Zhang, Xiaohong

2016-08-01

Biochar has great advantages in soil amendment and polluted soil remediation. Herein, the pore and adsorption properties of wine lees-derived biochar were explored. Specifically, the adsorption isotherm and kinetics of Pb(2+) onto wine lees-derived biochar were examined. Experimental results revealed that wine lees-derived biochar featured large specific surface area and total pore volume, and high contents of -COOH and -OH on its surface. Adsorption of Pb(2+) onto wine lees-derived biochar proceeded via a multilayer adsorption mechanism, as described by the Freundlich adsorption model. Adsorption kinetics followed the Lagergren pseudo-second-order kinetics model; adsorption equilibrium was achieved within 30-60 min. Furthermore, the effect of solution pH on the adsorption of Pb(2+) was investigated. Within the studied pH range of 3-6, the adsorption capacity increased with increasing pH. Under established optimized conditions, wine lees-derived biochar achieved a Pb(2+) adsorption capacity of 79.12 mg/g.

Biochar and microbial signaling: production conditions determine effects on microbial communication.

PubMed

Masiello, Caroline A; Chen, Ye; Gao, Xiaodong; Liu, Shirley; Cheng, Hsiao-Ying; Bennett, Matthew R; Rudgers, Jennifer A; Wagner, Daniel S; Zygourakis, Kyriacos; Silberg, Jonathan J

2013-10-15

Charcoal has a long soil residence time, which has resulted in its production and use as a carbon sequestration technique (biochar). A range of biological effects can be triggered by soil biochar that can positively and negatively influence carbon storage, such as changing the decomposition rate of organic matter and altering plant biomass production. Sorption of cellular signals has been hypothesized to underlie some of these effects, but it remains unknown whether the binding of biochemical signals occurs, and if so, on time scales relevant to microbial growth and communication. We examined biochar sorption of N-3-oxo-dodecanoyl-L-homoserine lactone, an acyl-homoserine lactone (AHL) intercellular signaling molecule used by many gram-negative soil microbes to regulate gene expression. We show that wood biochars disrupt communication within a growing multicellular system that is made up of sender cells that synthesize AHL and receiver cells that express green fluorescent protein in response to an AHL signal. However, biochar inhibition of AHL-mediated cell-cell communication varied, with the biochar prepared at 700 °C (surface area of 301 m(2)/g) inhibiting cellular communication 10-fold more than an equivalent mass of biochar prepared at 300 °C (surface area of 3 m(2)/g). These findings provide the first direct evidence that biochars elicit a range of effects on gene expression dependent on intercellular signaling, implicating the method of biochar preparation as a parameter that could be tuned to regulate microbial-dependent soil processes, like nitrogen fixation and pest attack of root crops.

Biochar and microbial signaling: production conditions determine effects on microbial communication

PubMed Central

Masiello, Caroline A.; Chen, Ye; Gao, Xiaodong; Liu, Shirley; Cheng, Hsiao-Ying; Bennett, Matthew R.; Rudgers, Jennifer A.; Wagner, Daniel S.; Zygourakis, Kyriacos; Silberg, Jonathan J.

2013-01-01

Charcoal has a long soil residence time, which has resulted in its production and use as a carbon sequestration technique (biochar). A range of biological effects can be triggered by soil biochar that can positively and negatively influence carbon storage, such as changing the decomposition rate of organic matter and altering plant biomass production. Sorption of cellular signals has been hypothesized to underlie some of these effects, but it remains unknown whether the binding of biochemical signals occurs, and if so, on time scales relevant to microbial growth and communication. We examined biochar sorption of N-3-oxo-dodecanoyl-L-homoserine lactone, an acyl-homoserine lactone (AHL) intercellular signaling molecule used by many gram-negative soil microbes to regulate gene expression. We show that wood biochars disrupt communication within a growing multicellular system that is made up of sender cells that synthesize AHL and receiver cells that express green fluorescent protein in response to an AHL signal. However, biochar inhibition of AHL-mediated cell-cell communication varied, with the biochar prepared at 700°C (surface area of 301 m2/g) inhibiting cellular communication 10-fold more than an equivalent mass of biochar prepared at 300°C (surface area of 3 m2/g). These findings provide the first direct evidence that biochars elicit a range of effects on gene expression dependent on intercellular signaling, implicating the method of biochar preparation as a parameter that could be tuned to regulate microbial-dependent soil processes, like nitrogen fixation and pest attack of root crops. PMID:24066613

Biochar activated by oxygen plasma for supercapacitors

NASA Astrophysics Data System (ADS)

Gupta, Rakesh Kumar; Dubey, Mukul; Kharel, Parashu; Gu, Zhengrong; Fan, Qi Hua

2015-01-01

Biochar, also known as black carbon, is a byproduct of biomass pyrolysis. As a low-cost, environmental-friendly material, biochar has the potential to replace more expensive synthesized carbon nanomaterials (e.g. carbon nanotubes) for use in future supercapacitors. To achieve high capacitance, biochar requires proper activation. A conventional approach involves mixing biochar with a strong base and baking at a high temperature. However, this process is time consuming and energy inefficient (requiring temperatures >900 °C). This work demonstrates a low-temperature (<150 °C) plasma treatment that efficiently activates a yellow pine biochar. Particularly, the effects of oxygen plasma on the biochar microstructure and supercapacitor characteristics are studied. Significant enhancement of the capacitance is achieved: 171.4 F g-1 for a 5-min oxygen plasma activation, in comparison to 99.5 F g-1 for a conventional chemical activation and 60.4 F g-1 for untreated biochar. This enhancement of the charge storage capacity is attributed to the creation of a broad distribution in pore size and a larger surface area. The plasma activation mechanisms in terms of the evolution of the biochar surface and microstructure are further discussed.

Improving the surface properties of municipal solid waste-derived pyrolysis biochar by chemical and thermal activation: Optimization of process parameters and environmental application.

PubMed

Genuino, Divine Angela D; de Luna, Mark Daniel G; Capareda, Sergio C

2018-02-01

Biochar produced from the slow pyrolysis of municipal solid waste was activated with KOH and thermal treatments to enhance its surface and adsorptive properties. The effects of KOH concentration, activation temperature and time on the specific surface area (SSA) of the activated biochar were evaluated and optimized using central composite design (CCD) of the response surface methodology (RSM). Results showed that the activation of biochar enhanced its SSA from 402.8 ± 12.5 to 662.4 ± 28.6 m 2  g -1 . The adsorptive capacities of the pristine biochar (PBC) and activated biochar (ABC) were compared using methylene blue (MB) dye as model compound. For MB concentrations up to 25 mg L -1 , more than 99% dye removal was achieved with ABC, while only a maximum of 51% was obtained with PBC. Results of the isotherm study showed that the Langmuir model best described MB adsorption on ABC with adsorption capacity of 37.0-41.2 mg g -1 . Copyright © 2017 Elsevier Ltd. All rights reserved.

Multiscale visualization of the structural and characteristic changes of sewage sludge biochar oriented towards potential agronomic and environmental implication

PubMed Central

Zhang, Jining; Lü, Fan; Zhang, Hua; Shao, Liming; Chen, Dezhen; He, Pinjing

2015-01-01

Sewage sludge biochars were obtained at different pyrolysis temperatures from 300°C to 900°C and their macro- and microscale properties were analyzed. The biochar's plant-available nutrients and humus-like substances in the water-extractable phase and fixed nutrients in the solid fraction were evaluated for their potential agronomic implications. FT-IR, Raman, XRD, XPS, and SEM techniques were used to investigate the chemical structure, functional groups, and microcrystal structure on the surface of the biochar. The results revealed minor chemical changes and dramatic mass loss in the biochar obtained at 300–500°C, whereas significant chemical changes in the biochar were obtained at 600–900°C. The concentrations of plant-available nutrients as well as fulvic- and humic-acid-like materials decreased in the biochar samples obtained at higher temperatures. These results implied that the biochar samples pyrolyzed at 300–500°C could be a direct nutrient source and used to neutralize alkaline soil. The surface area and porosity of the biochar samples increased with temperature, which increased their adsorption capacity. Rearrangement occurred at higher temperature 600–900°C, resulting in the biochar becoming increasingly polyaromatic and its graphite-like carbon becoming organized. PMID:25802185

Modification of biochar for functionality improvement in soils

NASA Astrophysics Data System (ADS)

Zwart, Kor; Kuikman, Peter; Ross, Anrew; Takaya, Chibi; Singh, Surjit; Kocaturk, Pelin; Visser, Rian

2014-05-01

Application of biochar to soils is generally considered and practiced in order to improve specific soil functions such as CEC, moisture and nutrient retention and providing additional habitat for micro-organisms. Improvement of these soil functions should lead to a higher crop yield. This would be added value to the long term sequestration of carbon in soils and contribution to renewable energy from producing and using biochar. The concept of using biochar for soil amendment is predicated on biochar behaving in a similar manner as soil organic matter (SOM) does. However, if one critically compares the properties of biochar with the properties of SOM, it is evident that biochar is rather different from SOM [Zwart, 2013 ;Zwart & Kuikman, 2013]. We have has produced a range of biochar from different feedstock using pyrolysis, gasification and hydrothermal carbonisation resulting in chars with significantly different properties. The project also investigates and tested several possibilities for improving the functionality of biochar in soils by either(i) selection of feedstock, (ii), selection of processing conditions and (iii) chemical and physical modification of biochar during and after the production process. Post modification includes the chemical treatment of biochars with either H2O2, KOH, H2SO4 and transitional metals such as Fe and investigates their effect on surface functionality, porosity, surface area, CEC and phosphate sorption. The influence of the addition of chemical modifiers and oxidants during pyrolysis and gasification has also been investigated and their effect on surface functionality determined using similar techniques. The influence of the original biomass structure on the morphology of the resultant biochars has been investigated using scanning electron microscopy.

The sorption and desorption of phosphate-P, ammonium-N and nitrate-N in cacao shell and corn cob biochars.

PubMed

Hale, S E; Alling, V; Martinsen, V; Mulder, J; Breedveld, G D; Cornelissen, G

2013-06-01

The sorption of PO4-P, NH4-N and NO3-N to cacao shell and corn cob biochars produced at 300-350°C was quantified. The biochars were used; (i) as received (unwashed), (ii) after rinsing with Millipore water and (iii) following leaching with Millipore water. In addition to sorption, desorption of PO4-P from the unwashed biochars was quantified. There was no sorption of PO4-P to either washed or rinsed biochars, but following leaching, both biochars adsorbed PO4-P and distribution coefficients (Kd L kg(-1)) were very similar for both materials (10(1.1±0.5) for cacao shell biochar and 10(1.0±0.2) for corn cob biochar). The BET surface area and micropore volume increased 80% and 60% for the cacao shell and corn cob biochars following leaching. After 60 d, 1483±45 mg kg(-1) and 172±1 mg kg(-1) PO4-P was released from the cacao shell and corn cob biochars. NH4-N was sorbed by both unwashed biochars, albeit weakly with Kd values around 10(2) L kg(-1). We speculate that NH4-N could bind via an electrostatic exchange with other cationic species on the surface of the biochar. There was no significant release or sorption of NO3-N from or to either of the biochars. Copyright © 2013 Elsevier Ltd. All rights reserved.

Promotion of hydrogen-rich gas and phenolic-rich bio-oil production from green macroalgae Cladophora glomerata via pyrolysis over its bio-char.

PubMed

Norouzi, Omid; Jafarian, Sajedeh; Safari, Farid; Tavasoli, Ahmad; Nejati, Behnam

2016-11-01

Conversion of Cladophora glomerata (C. glomerata) as a Caspian Sea's green macroalgae into gaseous, liquid and solid products was carried out via pyrolysis at different temperatures to determine its potential for bio-oil and hydrogen-rich gas production for further industrial utilization. Non-catalytic tests were performed to determine the optimum condition for bio-oil production. The highest portion of bio-oil was retrieved at 500°C. The catalytic test was performed using the bio-char derived at 500°C as a catalyst. Effect of the addition of the algal bio-char on the composition of the bio-oil and also gaseous products was investigated. Pyrolysis derived bio-char was characterized by BET, FESEM and ICP method to show its surface area, porosity, and presence of inorganic metals on its surface, respectively. Phenols were increased from 8.5 to 20.76area% by the addition of bio-char. Moreover, the hydrogen concentration and hydrogen selectivity were also enhanced by the factors of 1.37, 1.59 respectively. Copyright © 2016 Elsevier Ltd. All rights reserved.

Adsorption Mechanisms of Dodecylbenzene Sulfonic Acid by Corn Straw and Poplar Leaf Biochars

PubMed Central

Zhao, Nan; Yang, Xixiang; Zhang, Jing; Zhu, Ling; Lv, Yizhong

2017-01-01

Biochar is an eco-friendly, renewable, and cost-effective material that can be used as an adsorbent for the remediation of contaminated environments. In this paper, two types of biochar were prepared through corn straw and poplar leaf pyrolysis at 300 °C and 700 °C (C300, C700, P300, P700). Brunaer–Emmett–Teller N2 surface area, scanning electron microscope, elemental analysis, and infrared spectra were used to characterize their structures. These biochars were then used as adsorbents for the adsorption of dodecylbenzene sulfonic acid (DBSA). The microscopic adsorption mechanisms were studied by using infrared spectra, 13C-nuclear magnetic resonance spectra, and electron spin resonance spectra. The surface area and pore volume of C700 (375.89 m2/g and 0.2302 cm3/g) were the highest among all samples. Elemental analysis results showed that corn straw biochars had a higher aromaticity and carbon to nitrogen (C/N) ratio than the poplar leaf biochars. High temperature caused the increase of carbon content and the decrease of oxygen content, which also gave the biochars a higher adsorption rate. Pseudo-second order kinetic provided a better fit with the experimental data. Adsorption isotherm experiments showed that the adsorption isotherm of C300 fit the linear model. For other biochars, the adsorption isotherms fitted Langmuir model. Biochars with high temperatures exhibited enhanced adsorption capacity compared with ones at low temperatures. The qmax values of biochars to DBSA followed the order of P700 > C700 > P300. The adsorption mechanisms were complex, including partition, anion exchange, the formation of H bonds, covalent bonds, and charge transfer. The adsorption by covalent bonding might be the key mechanism determining the adsorption capacity of P700. PMID:28937637

Adsorption Mechanisms of Dodecylbenzene Sulfonic Acid by Corn Straw and Poplar Leaf Biochars.

PubMed

Zhao, Nan; Yang, Xixiang; Zhang, Jing; Zhu, Ling; Lv, Yizhong

2017-09-22

Biochar is an eco-friendly, renewable, and cost-effective material that can be used as an adsorbent for the remediation of contaminated environments. In this paper, two types of biochar were prepared through corn straw and poplar leaf pyrolysis at 300 °C and 700 °C (C300, C700, P300, P700). Brunaer-Emmett-Teller N₂ surface area, scanning electron microscope, elemental analysis, and infrared spectra were used to characterize their structures. These biochars were then used as adsorbents for the adsorption of dodecylbenzene sulfonic acid (DBSA). The microscopic adsorption mechanisms were studied by using infrared spectra, 13 C-nuclear magnetic resonance spectra, and electron spin resonance spectra. The surface area and pore volume of C700 (375.89 m²/g and 0.2302 cm³/g) were the highest among all samples. Elemental analysis results showed that corn straw biochars had a higher aromaticity and carbon to nitrogen (C/N) ratio than the poplar leaf biochars. High temperature caused the increase of carbon content and the decrease of oxygen content, which also gave the biochars a higher adsorption rate. Pseudo-second order kinetic provided a better fit with the experimental data. Adsorption isotherm experiments showed that the adsorption isotherm of C300 fit the linear model. For other biochars, the adsorption isotherms fitted Langmuir model. Biochars with high temperatures exhibited enhanced adsorption capacity compared with ones at low temperatures. The q max values of biochars to DBSA followed the order of P700 > C700 > P300. The adsorption mechanisms were complex, including partition, anion exchange, the formation of H bonds, covalent bonds, and charge transfer. The adsorption by covalent bonding might be the key mechanism determining the adsorption capacity of P700.

The importance of nano-porosity in the stalk-derived biochar to the sorption of 17β-estradiol and retention of it in the greenhouse soil.

PubMed

Zhang, Fengsong; Li, Yanxia; Zhang, Guixiang; Li, Wei; Yang, Lingsheng

2017-04-01

Natural estrogens in greenhouse soils with long-term manure application are becoming a potential threat to adjacent aquatic environment. Porous stalk biochar as a cost-effective adsorbent of estrogen has a strong potential to reduce their transportation from soil to waters. But the dominant adsorption mechanism of estrogen to stalk biochars and retention of estrogen by greenhouse soils amended with biochar are less well known. Element, function groups, total surface area (SA total ), nano-pores of stalk biochars, and chemical structure of 17β-estradiol (E2, length 1.20 nm, width 0.56 nm, thickness 0.48 nm) are integrated in research on E2 sorption behavior in three stalk-derived biochars produced from wheat straw (WS), rice straw (RS), and corn straw (CS), and greenhouse soils amended with optimal biochar. The three biochars had comparable H/C and (O + N)/C, while their aromatic carbon contents and total surface areas (SA total ) both varied as CS > WS > RS. However, WS had the highest sorption capacity (logK oc ), sorption affinity (K f ), and strongest nonlinearity (n). Additionally, the variation of Langmuir maximum adsorption capacity (Q 0 ) was consistent with the trend for SA 1.2-20 (WS > RS > CS) but contrary to the trend for SA total and SA <1.2 (CS > WS > RS). These results indicate that pore-filling dominates the sorption of E2 by biochars and exhibits "sieving effect" and length-directionality-specific via H-bonding between -OH groups on the both ends of E2 in the length direction and polar groups on the inner surface of pores. After the addition of wheat straw biochar, the extent of increase in the sorption affinity for E2 in the soil with low OC content was higher than those in the soil with high OC content. Therefore, the effectiveness for the wheat straw biochar mitigating the risk of E2 in greenhouse soil depended on the compositions of soil, especially organic matter.

Adsorption of Cd(II) from aqueous solutions by rape straw biochar derived from different modification processes.

PubMed

Li, Bing; Yang, Lan; Wang, Chang-Quan; Zhang, Qing-Pei; Liu, Qing-Cheng; Li, Yi-Ding; Xiao, Rui

2017-05-01

In order to deal with cadmium (Cd(II)) pollution, three modified biochar materials: alkaline treatment of biochar (BC-NaOH), KMnO 4 impregnation of biochar (BC-MnO x ) and FeCl 3 magnetic treatment of biochar (BC-FeO x ), were investigated. Nitrogen adsorption-desorption isotherms, Fourier transform infrared spectroscopy (FTIR), Boehm titration, and scanning electron microscopy (SEM) were used to determine the characteristics of adsorbents and explore the main adsorption mechanism. The results show that manganese oxide particles are carried successfully within the biochar, contributing to micropore creation, boosting specific surface area and forming innersphere complexes with oxygen-containing groups, while also increasing the number of oxygen-containing groups. The adsorption sites created by the loaded manganese oxide, rather than specific surface areas, play the most important roles in cadmium adsorption. Batch adsorption experiments demonstrate a Langmuir model fit for Cd(II), and BC-MnO x provided the highest sorption capacity (81.10 mg g -1 ). The sorption kinetics of Cd(II) on adsorbents follows pseudo-second-order kinetics and the adsorption rate of the BC-MnO x material was the highest (14.46 g (mg·h) -1 ). Therefore, biochar modification methods involving KMnO 4 impregnation may provide effective ways of enhancing Cd(II) removal from aqueous solutions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Properties of the plant- and manure-derived biochars and their sorption of dibutyl phthalate and phenanthrene

NASA Astrophysics Data System (ADS)

Qiu, Mengyi; Sun, Ke; Jin, Jie; Gao, Bo; Yan, Yu; Han, Lanfang; Wu, Fengchang; Xing, Baoshan

2014-06-01

The properties of plant residue-derived biochars (PLABs) and animal waste-derived biochars (ANIBs) obtained at low and high heating treatment temperatures (300 and 450°C) as well as their sorption of dibutyl phthalate (DBP) and phenanthrene (PHE) were investigated in this study. The higher C content of PLABs could explain that CO2-surface area (CO2-SA) of PLABs was remarkably high relative to ANIBs. OC and aromatic C were two key factors influencing the CO2-SA of the biochars. Much higher surface C content of the ANIBs than bulk C likely explained that the ANIBs exhibited higher sorption of DBP and PHE compared to the PLABs. H-bonding should govern the adsorption of DBP by most of the tested biochars and π-π interaction play an important role in the adsorption of PHE by biochars. High CO2-SA (>200 m2 g-1) demonstrated that abundant nanopores of OC existed within the biochars obtained 450°C (HTBs), which likely result in high and nonlinear sorption of PHE by HTBs.

Gasification reactor engineering approach to understanding the formation of biochar properties

PubMed Central

2016-01-01

The correlation between thermochemical provenance and biochar functionality is poorly understood. To this end, operational reactor temperatures (spanning the reduction zone), pressure and product gas composition measurements were obtained from a downdraft gasifier and compared against elemental composition, surface morphology and polyaromatic hydrocarbon content (PAH) of the char produced. Pine feedstock moisture with values of 7% and 17% was the experimental variable. Moderately high steady-state temperatures were observed inside the reactor, with a ca 50°C difference in how the gasifier operated between the two feedstock types. Both chars exhibited surface properties comparable to activated carbon, but the relatively small differences in temperature caused significant variations in biochar surface area and morphology: micropore area 584 against 360 m2 g−1, and micropore volume 0.287 against 0.172 cm3 g−1. Differences in char extractable PAH content were also observed, with higher concentrations (187 µg g−1 ± 18 compared with 89 ± 19 µg g−1 Σ16EPA PAH) when the gasifier was operated with higher moisture content feedstock. It is recommended that greater detail on operational conditions during biochar production should be incorporated to future biochar characterization research as a consequence of these results. PMID:27616911

Synthesis, characterization, and environmental implications of graphene-coated biochar.

PubMed

Zhang, Ming; Gao, Bin; Yao, Ying; Xue, Yingwen; Inyang, Mandu

2012-10-01

Biochar has attracted much research attention recently because of its potential applications in many environmental areas. In this work, the biochar technology was combined with the emerging graphene technology to create a new engineered graphene-coated biochar from cotton wood. The biomass feedstock was first treated with graphene/pyrene-derivative and was then annealed at 600°C in a quartz tube furnace under N(2) environment. Laboratory characterization with different microscopy and spectrometry tools showed that the graphene sheets were "soldered" by the pyrene molecules on the biochar surface during the annealing process. Thermogravimetric analysis showed that the graphene "skin" could improve the thermal stability of the biochar, making the engineered biochar a better carbon sequester for large scale land applications. Batch sorption experimental results indicated that the graphene-coated biochar has excellent adsorption ability of polycyclic aromatic hydrocarbons (PAHs) with a maximum methylene blue adsorption capacity of 174 mg g(-1), which is more than 20 times higher than that of the unmodified cotton wood biochar and comparable to those of some physically or chemically activated carbons. The enhanced adsorption of methylene blue on the graphene-coated biochar is mainly controlled by the strong π-π interactions between aromatic molecules and the graphene sheets on biochar surface. It is anticipated that this novel, facile, and low-cost method can be expanded to other carbon-rich materials to create engineered biochar for various environmental applications. Copyright © 2012 Elsevier B.V. All rights reserved.

Porous nano-cerium oxide wood chip biochar composites for aqueous levofloxacin removal and sorption mechanism insights.

PubMed

Yi, Shengze; Sun, Yuanyuan; Hu, Xin; Xu, Hongxia; Gao, Bin; Wu, Jichun

2017-01-14

The adsorption removal of levofloxacin (LEV), a widely used fluoroquinolone antibiotic, by using the biochars derived from the pyrolysis of pine wood chip pretreated with cerium trichloride was investigated through batch sorption experiments and multiple characterization techniques. The differences in the basic physicochemical properties between Ce-impregnated biochars and the pristine biochars were confirmed by the analysis of elemental compositions, specific surface areas, energy dispersive spectrometry, X-ray diffraction, and thermo-gravimetry. FT-IR spectra of the pre- and post-sorption biochars confirmed the chemical adsorption for LEV sorption onto the biochars. Large shifts in the binding energy of Ce 3d , O 1s , C 1s , and N 1s regions on the pre- and post-sorption biochars indicated the surface complexation of LEV molecule onto the biochars. The binding species of Ce 4+ and Ce 3+ identified by X-ray photoelectron spectroscopy reflect the role of Ce oxides during sorption. Batch adsorption showed the significant enhancement of adsorption capacity for LEV after the Ce modification. Batch adsorption kinetic data fitted well with the pseudo-second-order model. Both the Langmuir and the Freundlich models reproduced the isotherm data well. Findings from this work indicated that Ce-impregnated biochars can be effective for the removal of aqueous LEV.

Geoelectrical Monitoring of Ammonium Sorption Processes in a Biochar Filtration System

NASA Astrophysics Data System (ADS)

Wang, S. L.; Osei, C.; Rabinovich, A.; Ntarlagiannis, D.; Rouff, A.

2017-12-01

With the rise of modern agriculture, nutrient pollution has become an increasingly important environmental concern. A common problem is excess nitrogen which agricultural livestock farms often generate in the form of ammonium (NH4+). This highly soluble ion is easily transported through runoff and leaching, leading to water supply contamination and soil fertility decline. Biochar is the carbon-rich product of thermal decomposition of biomass in an oxygen-free environment. It is primarily used as a soil enhancer with other applications currently under research. Biochar's unique characteristics such as high surface area, high sorption capacity and long term biological and chemical stability make it a prime candidate for environmental applications such as contaminant regulation and waste effluent treatment. The spectral induced polarization (SIP) method is an established geoelectrical method that has been increasingly used in environmental investigations. SIP is unique among geophysical methods because it is sensitive not only to the bulk properties of the medium under investigation but also to the interfacial properties (e.g., mineral-fluid). The unique properties that make biochar attractive for environmental use are associated with surface properties (e.g., surface area, surface charge, presence of functional groups) that are expected to have a profound effect on SIP signals. This study presents early results on the use of the SIP method to monitor ammonium recycling of swine wastewater in a biochar filtration system. SIP measurements were taken continuously as biochar-packed columns were first injected with an ammonium wastewater solution (sorption phase) and then an ammonium-free solution (desorption phase). Geochemical monitoring showed that outflow ammonium concentration decreased during the sorption phase and increased during the desorption phase. The collected SIP data appear to be in agreement with the geochemical monitoring, providing a temporally continuous record of changes on the waste fluid and biochar surface. The results suggest that biochar successfully sorbs and releases ammonium and that the SIP method is sensitive these sorption processes. Further research is required for the quantitative interpretation of the SIP signals, including the signal source mechanism.

Catalytic microwave pyrolysis of oil palm fiber (OPF) for the biochar production.

PubMed

Hossain, Md Arafat; Ganesan, Poo Balan; Sandaran, Shanti Chandran; Rozali, Shaifulazuar Bin; Krishnasamy, Sivakumar

2017-12-01

Microwave pyrolysis of oil palm fiber (OPF) with three types of Na-based catalysts was experimentally investigated to produce biochar. Sodium hydroxide (NaOH), sodium chloride (NaCl), and sodium carbonate (Na 2 CO 3 ) with purity 99.9% were selected for this investigation. Microwave muffle reactor (Model: HAMiab-C1500) with a microwave power controller including a microwave generator was used to perform the microwave pyrolysis. OPF particles were used after removing foreign materials, impurities, and dust. Microwave power ranges from 400 to 900 W, temperature ranges from 450 to 700 °C, and N 2 flow rates ranges from 200 to -1200 cm 3 /min were used along with all three Na-based catalysts for this investigation. Lower microwave power, temperature, and N 2 flow rate have been found favorable for higher yield of biochar. NaOH is to be found as the more suitable catalyst than NaCl and Na 2 CO 3 to produce biochar. A maximum biochar yield (51.42 wt%) has been found by using the catalysts NaOH at N 2 flow rate of 200 cm 3 /min. One sample of the biochar (maximum yield without catalysts) was selected for further characterization via thermo gravimetric analysis (TGA), scanning electron microscopy (SEM), BET surface area, Fourier transform infrared spectroscopy (FTIR), and ultimate and proximate analysis. SEM and BET surface area analysis showed the presence of some pores in the biochar. High percentage of carbon (60.24 wt%) was also recorded in the sample biochar. The pores and high percentage of carbon of biochar have significant impact on soil fertilization by increasing the carbon sequestration in the soil. It assists to slow down the decomposition rate of nutrients from soil and therefore enhances the soil quality.

Biochar for composting improvement and contaminants reduction. A review.

PubMed

Godlewska, Paulina; Schmidt, Hans Peter; Ok, Yong Sik; Oleszczuk, Patryk

2017-12-01

Biochar is characterised by a large specific surface area, porosity, and a large amount of functional groups. All of those features cause that biochar can be a potentially good material in the optimisation of the process of composting and final compost quality. The objective of this study was to compile the current knowledge on the possibility of biochar application in the process of composting and on the effect of biochar on compost properties and on the content of contaminants in compost. The paper presents the effect of biochar on compost maturity indices, composting temperature and moisture, and also on the content and bioavailability of nutrients and of organic and inorganic contaminants. In the paper note is also taken of the effect of biochar added to composted material on plants, microorganisms and soil invertebrates. Copyright © 2017 Elsevier Ltd. All rights reserved.

Physical and chemical characterization of waste wood derived biochars

USDA-ARS?s Scientific Manuscript database

Biochar, a solid byproduct generated during waste biomass pyrolysis or gasification in the absence (or near-absence) of oxygen, has recently garnered interest for both agricultural and environmental management purposes owing to its unique physicochemical properties, such as its high surface area and...

Properties comparison of biochars from corn straw with different pretreatment and sorption behaviour of atrazine.

PubMed

Zhao, Xuchen; Ouyang, Wei; Hao, Fanghua; Lin, Chunye; Wang, Fangli; Han, Sheng; Geng, Xiaojun

2013-11-01

Biochar has been recognised as an efficient pollution control material. In this study, biochars (CS450 and ADPCS450) were produced using corn straw with different pretreatment techniques (without and with ammonium dihydrogen phosphate (ADP)). The character of the two biochars was compared using elemental analysis, specific surface area (SSA) and Fourier transform infrared spectra (FTIR). ADPCS450 had a higher residue yield and a much larger specific surface area than CS450. The Freundlich, Langmuir and Redlich-Peterson models were used to interpret the sorption behaviour of atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine), and the results fit the Redlich-Peterson equation best. The isothermal sorption parameters indicated that the sorption capacity of atrazine on ADPCS450 was much larger than the sorption capacity of atrazine on CS450. Atrazine sorption was also favoured in acidic solution and under higher temperature conditions. Copyright © 2013 Elsevier Ltd. All rights reserved.

Biochar characteristics produced from rice husks and their sorption properties for the acetanilide herbicide metolachlor.

PubMed

Wei, Lan; Huang, Yufen; Li, Yanliang; Huang, Lianxi; Mar, Nyo Nyo; Huang, Qing; Liu, Zhongzhen

2017-02-01

Rice husk biochar (RHBC) was prepared for use as adsorbents for the herbicide metolachlor. The characteristics and sorption properties of metolachlor adsorbed by the RHBC prepared at different pyrolysis temperatures were determined by analysis of physico-chemical characteristics, Fourier transform infrared spectroscopy (FTIR), Boehm titration, scanning electron microscopy (SEM), and thermodynamics and kinetics adsorption. With increasing pyrolysis temperature, the RHBC surface area greatly increased (from 2.57 to 53.08 m 2  g -1 ). RHBC produced at the highest temperature (750 °C) had the greatest surface area; SEM also showed the formation of a porous surface on RH-750 biochar. The sorption capacity of RHBC also increased significantly with increasing pyrolysis temperature and was characterized by the Freundlich constant K f for the adsorption capacity increasing from 125.17-269.46 (pyrolysis at 300 °C) to 339.94-765.24 (pyrolysis at 750 °C). The results indicated that the surface area and pore diameter of RHBC produced with high pyrolysis temperature (i.e., 750 °C) had the greatest impact on the adsorption of metolachlor. The FTIR, Boehm titration, and SEM analysis showed that the greatest number of surface groups were on RHBC produced at the lowest temperature (300 °C). The biochars produced at different pyrolysis temperatures had different mechanisms of adsorbing metolachlor, which exhibited a transition from hydrogen bonds dominant at low pyrolytic temperature to pore-filling dominant at higher pyrolytic temperature.

The hierarchical porous structure bio-char assessments produced by co-pyrolysis of municipal sewage sludge and hazelnut shell and Cu(II) adsorption kinetics.

PubMed

Zhao, Bing; Xu, Xinyang; Zeng, Fanqiang; Li, Haibo; Chen, Xi

2018-05-04

The co-pyrolysis technology was applied to municipal sewage sludge (MSS) and hazelnut shell with alkaline activating agent K 2 CO 3 under N 2 atmosphere. The innovative bio-char produced by co-pyrolysis had significant physical and chemical characteristics. The specific surface area reached 1990.23 m 2 /g, and the iodine absorption number was 1068.22 mg/g after co-pyrolysis at 850 °C. Although hazelnut shell was a kind of solid waste, it also had abundant cellulose resource, which could contribute to porous structure of bio-char during co-pyrolysis with MSS and decrease total heavy metals contents of raw material to increase security of bio-chars. Meanwhile, the residual fractions of heavy metals in bio-char were above 92.95% after co-pyrolysis at 900 °C except Cd to prevent heavy metals digestion, and the bio-char presented significant immobilization behavior from co-pyrolysis technology. Moreover, the yield and the iodine absorption number of bio-chars under different process variables were analyzed, and it was confirmed that appropriate process variables could contribute the yield and the iodine absorption number of bio-char and prevent to etch pore structure excessively to collapse. The changes of surface functional groups and crystallographic structure before and after co-pyrolysis were analyzed by FTIR and XRD, respectively. The hierarchical porous structure of bio-char was presented by SEM and N 2 adsorption-desorption isotherm. The Cu(II) adsorption capacity of the bio-char was 42.28 mg/g after 24 h, and surface functional groups acted as active binding sites for Cu(II) adsorption. Langmuir model and pseudo-second-order model can describe process of Cu(II) adsorption well.

Kinetic and isothermal adsorption-desorption of PAEs on biochars: effect of biomass feedstock, pyrolysis temperature, and mechanism implication of desorption hysteresis.

PubMed

Jing, Fanqi; Pan, Minjun; Chen, Jiawei

2018-04-01

Biochar has the potential to sequester biomass carbon efficiently into land, simultaneously while improving soil fertility and crop production. Biochar has also attracted attention as a potential sorbent for good performance on adsorption and immobilization of many organic pollutants such as phthalic acid esters (PAEs), a typical plasticizer in plastic and presenting a current environmental issue. Due to lack of investigation on the kinetic and thermodynamic adsorption-desorption of PAEs on biochar, we systematically assessed adsorption-desorption for two typical PAEs, dimethyl phthalate (DMP) and diethyl phthalate (DEP), using biochar derived from peanut hull and wheat straw at different pyrolysis temperatures (450, 550, and 650 °C). The aromaticity and specific surface area of biochars increased with the pyrolysis temperature, whereas the total amount of surface functional groups decreased. The quasi-second-order kinetic model could better describe the adsorption of DMP/DEP, and the adsorption capacity of wheat straw biochars was higher than that of peanut hull biochars, owing to the O-bearing functional groups of organic matter on exposed minerals within the biochars. The thermodynamic analysis showed that DMP/DEP adsorption on biochar is physically spontaneous and endothermic. The isothermal desorption and thermodynamic index of irreversibility indicated that DMP/DEP is stably adsorbed. Sorption of PAEs on biochar and the mechanism of desorption hysteresis provide insights relevant not only to the mitigation of plasticizer mobility but also to inform on the effect of biochar amendment on geochemical behavior of organic pollutants in the water and soil.

Effect of biochar activation by different methods on toxicity of soil contaminated by industrial activity.

PubMed

Kołtowski, Michał; Charmas, Barbara; Skubiszewska-Zięba, Jadwiga; Oleszczuk, Patryk

2017-02-01

The objective of the study was to determine the effect of various methods of biochar activation on the ecotoxicity of soils with various properties and with various content and origin of contaminants. The biochar produced from willow (at 700°C) was activated by 1) microwaves (in a microwave reactor under an atmosphere of water vapour), 2) carbon dioxide (in the quartz fluidized bed reactor) and 3) superheated steam (in the quartz fluidized bed reactor). Three different soils were collected from industrial areas. The soils were mixed with biochar and activated biochars at the dose of 5% and ecotoxicological parameters of mixture was evaluated using two solid phase test - Phytotoxkit F (Lepidium sativum) and Collembolan test (Folsomia candida) and one liquid phase test - Microtox® (Vibrio fischeri). Biochar activation had both positive and negative impacts, depending on the activation method, kind of bioassay and kind of soil. Generally, biochar activated by microwaves increased the effectiveness of ecotoxicity reduction relative to non-activated biochars. Whereas, biochar activated with CO 2 most often cause a negative effect manifested by deterioration or as a lack of improvement in relation to non-activated biochar or to non-amended soil. It was also demonstrated that the increase of biochar specific surface area caused a significant reduction of toxicity of water leachates from the studied soils. Effectiveness of the reduction of leachate toxicity was weakened in the presence of dissolved organic carbon in the soil. Copyright © 2016 Elsevier Inc. All rights reserved.

Differential effects of biochar on soils within an eroded field

NASA Astrophysics Data System (ADS)

Schumacher, Thomas; Chintala, Rajesh; Sandhu, Saroop; Kumar, Sandeep; Clay, Dave; Gelderman, Ron; Papiernik, Sharon; Malo, Douglas; Clay, Sharon; Julson, Jim

2015-04-01

Future uses of biochar will in part be dependent not only on the effects of biochar on soil processes but also on the availability and economics of biochar production. If pyrolysis for production of bio-oil and syngas becomes wide-spread, biochar as a by-product of bio-oil production will be widely available and relatively inexpensive compared to the production of biochar as primary product. Biochar produced as a by-product of optimized bio-oil production using regionally available feedstocks was examined for properties and for use as an amendment targeted to contrasting soils within an eroded field in an on-farm study initiated in 2013 at Brookings, South Dakota, USA. Three plant based biochar materials produced from carbon optimized gasification of corn stover (Zea mays L.), Ponderosa pine (Pinus ponderosa Lawson and C. Lawson) wood residue, and switchgrass (Panicum virgatum L.) were applied at a 1% (w/w) rate to a Maddock soil (Sandy, Mixed, Frigid Entic Hapludolls) located in an eroded upper landscape position and a Brookings soil (Fine-Silty, Mixed, Superactive, Frigid Pachic Hapludolls) located in a depositional landscape position. The cropping system within this agricultural landscape was a corn (Zea mays L.) and soybean (Glycine max L.) rotation. Biochar physical and chemical properties for each of the feedstocks were determined including pH, surface area, surface charge potential, C-distribution, ash content, macro and micro nutrient composition. Yields, nutrient content, and carbon isotope ratio measurements were made on the harvested seed. Soil physical properties measured included water retention, bulk density, and water infiltration from a ponded double ring infiltrometer. Laboratory studies were conducted to determine the effects of biochar on partitioning of nitrate and phosphorus at soil surface exchange complex and the extracellular enzymes activity of C and N cycles. Crop yields were increased only in the Maddock soil. Biochar interacted with each soil type to alter physical and chemical properties. However the pattern of interaction depended on soil and biochar type.

Biochars change the sorption and degradation of thiacloprid in soil: Insights into chemical and biological mechanisms.

PubMed

Zhang, Peng; Sun, Hongwen; Min, Lujuan; Ren, Chao

2018-05-01

One interest of using biochar as soil amendment is to reduce pesticide adverse effects. In this paper, the sorption and degradation of thiacloprid (THI) in a black soil amended by various biochars were systematically investigated, and the mechanisms therein were explored by analyzing the changes in soil physicochemical properties, degrading enzymes and genes and microorganism community. Biochar amendment increased THI sorption in soil, which was associated with an increase in organic carbon and surface area and a decrease in H/C. Amendments of 300-PT (pyrolyzing temperature) biochar promoted the biodegradation of THI by increasing the microbe abundance and improving nitrile hydratase (NHase) activity. In contrast, 500- and 700-PT biochar amendments inhibited biodegradation by reducing THI availability and changing NHase activity and THI-degradative nth gene abundance, and instead promoted chemical degradation mainly through elevated pH, active groups on mineral surface and generation of •OH and other free radicals. Furthermore, THI shifted the soil microbial community, stimulated the NHase activity and elevated nth gene abundance. Biochar amendments also changed soil bacterial community by modulating soil pH, dissolved organic matter and nitrogen and phosphorus levels, which further influenced THI biodegradation. Therefore, the impact of biochars on the fate of a pesticide in soil depends greatly on their type and properties, which should be comprehensively examined when applying biochar to soil. Copyright © 2018 Elsevier Ltd. All rights reserved.

Sorption of water by biochar: Closer look at micropores

NASA Astrophysics Data System (ADS)

Spokas, Kurt; Hall, Kathleen; Joseph, Stephan; Kammann, Claudia; Novak, Jeffrey; Gámiz, Beatriz; Cox, Lucia

2017-04-01

Typically, biochar has been assumed to increase total water content of the soil system and thereby positively influence plant-soil moisture hydraulics. In this work, we focused on water's interaction with micro-pores (<2 nm) and its influence on water availability. In other words, the main question was if the driving force of water's behavior was the physics or chemistry of biochar pores. The temporal scale of liquid water entry into biochar's pore network is very complex, with observed bubbling occurring days, weeks, and even months after a piece of biochar is immersed under water at ambient conditions. Elevated temperature biochar typically has a positive heat of immersion measured calorimetrically, whereas the calculated BET energy of sorption from a water sorption isotherm typically decrease with production temperatures. To further complicate matters, different pieces of biochar interact differently with water even though the entire batch was created in the same reactor at the same time and after liquid water exposure the physical structure of biochar is irreversibly altered, sometimes negligible other times catastrophically. Nevertheless, based on the estimations of diffusion coefficients in biochar from drying curve analyses, pore surface moieties do reduce the effective diffusivity of water vapor in biochar. Contrary to the rule of thumb in soil physics, where higher gas filled porosity correlates with higher soil moisture holding capacities, our results indicate that biochar's water sorption rate and capacity is actually reduced at ambient conditions by an increase in microporous volume. Thereby, biochar's hydrophobic behavior is partly due to the entrapment of gas within the air-filled porosity which prevents liquid water's entry, even though these biochars possess elevated gas phase sorption capacities (e.g., BET N2/CO2 surface areas).

Activated biochar: Preparation, characterization and electroanalytical application in an alternative strategy of nickel determination.

PubMed

Kalinke, Cristiane; Oliveira, Paulo Roberto; Oliveira, Geovane Arruda; Mangrich, Antonio Sálvio; Marcolino-Junior, Luiz H; Bergamini, Márcio F

2017-08-29

This work reports for the first time the use of chemically activated biochar as electrode modifier for nickel determination. The biochar activation was performed by refluxing with HNO 3 , which promoted a higher nickel preconcentration compared to unmodified and modified biochar precursor electrodes. Morphological and structural characterization revealed the increase of surface acid groups, surface area and porosity of biochar after activation. Nickel determination was investigated adopting an alternative voltammetric methodology based on monitoring the Ni(II)/Ni(III) redox couple. In the proposed method, it was not necessary to use a complexing agent and the biochar itself was responsible for the analyte preconcentration. A linear response for Ni(II) concentration range from 1.0 to 30 μmol L -1 and a limit of detection of 0.25 μmol L -1 were obtained. The method was successfully applied for Ni(II) determination in spiked samples of bioethanol fuel and discharge water, with recoveries values between 103 and 109%. Copyright © 2017 Elsevier B.V. All rights reserved.

Biochar-based functional materials in the purification of agricultural wastewater: Fabrication, application and future research needs.

PubMed

Wei, Dongning; Li, Bingyu; Huang, Hongli; Luo, Lin; Zhang, Jiachao; Yang, Yuan; Guo, Jiajun; Tang, Lin; Zeng, Guangming; Zhou, Yaoyu

2018-04-01

Nowadays, agricultural contamination is becoming more and more serious due to the rapid growth of agricultural industry, which discharged antibiotics, pesticides or toxic metals into farmlands. A large number of researchers have applied biochar-based functional materials to the treatment of agricultural wastewater contamination. Meanwhile, biochar has also proved to be a very promising and effective technology in water purification field due to its various beneficial properties (e.g., cost effective, high specific surface area, and surface reactive groups). The focus of this review is to highlight the fabrication methods and application of biochar-based functional materials with the removal of different agricultural contaminants, and discuss the underlying mechanisms. However, the application of biochar-based functional materials is currently under its infancy, with the main hindrance is identified as the gap between laboratory scale and field application, immaturity of engineered biochar production technologies, and lack of quality standards. In order to fill these knowledge gaps, more efforts should be made to pay for the relevant research in future studies. Copyright © 2018 Elsevier Ltd. All rights reserved.

Comprehensive Adsorption Studies of Doxycycline and Ciprofloxacin Antibiotics by Biochars Prepared at Different Temperatures

PubMed Central

Zeng, Zhi-wei; Tan, Xiao-fei; Liu, Yun-guo; Tian, Si-rong; Zeng, Guang-ming; Jiang, Lu-hua; Liu, Shao-bo; Li, Jiang; Liu, Ni; Yin, Zhi-hong

2018-01-01

This paper comparatively investigated the removal efficiency and mechanisms of rice straw biochars prepared under three pyrolytic temperatures for two kinds of tetracycline and quinolone antibiotics (doxycycline and ciprofloxacin). The influencing factors of antibiotic adsorption (including biochar dosage, pH, background electrolytes, humic acid, initial antibiotics concentration, contact time, and temperature) were comprehensively studied. The results suggest that biochars produced at high-temperature [i.e., 700°C (BC700)], have higher adsorption capacity for the two antibiotics than low-temperature (i.e., 300–500°C) biochars (BC300 and BC500). Higher surface area gives rise to greater volume of micropores and mesopores, and higher graphitic surfaces of the BC700 contributed to its higher functionality. The maximum adsorption capacity was found to be in the following order: DOX > CIP. The π-π EDA interaction and hydrogen bonding might be the predominant adsorption mechanisms. Findings in this study highlight the important roles of high-temperature biochars in controlling the contamination of tetracycline and quinolone antibiotics in the environment. PMID:29637067

Comprehensive adsorption studies of doxycycline and ciprofloxacin antibiotics by biochars prepared at different temperatures

NASA Astrophysics Data System (ADS)

Zeng, Zhi-wei; Tan, Xiao-fei; Liu, Yun-guo; Tian, Si-rong; Zeng, Guang-ming; Jiang, Lu-hua; Liu, Shao-bo; Li, Jiang; Liu, Ni; Yin, Zhi-hong

2018-03-01

This paper comparatively investigated the removal efficiency and mechanisms of rice straw biochars prepared under three pyrolytic temperatures for two kinds of tetracycline and quinolone antibiotics (doxycycline and ciprofloxacin). The influencing factors of antibiotic adsorption (including biochar dosage, pH, background electrolytes, humic acid, initial antibiotics concentration, contact time, and temperature) were comprehensively studied. The results suggest that biochars produced at high-temperature (i.e., 700°C (BC700)), have higher adsorption capacity for the two antibiotics than low-temperature (i.e., 300-500°C) biochars (BC300 and BC500). Higher surface area gives rise to greater volume of micropores and mesopores, and higher graphitic surfaces of the BC700 contributed to its higher functionality. The maximum adsorption capacity was found to be in the following order: DOX > CIP. The π-π EDA interaction and hydrogen bonding might be the predominant adsorption mechanisms. Findings in this study highlight the important roles of high-temperature biochars in controlling the contamination of tetracycline and quinolone antibiotics in the environment.

Phenylurea herbicide sorption to biochars and agricultural soil

PubMed Central

WANG, DAOYUAN; MUKOME, FUNGAI N. D.; YAN, DENGHUA; WANG, HAO; SCOW, KATE M.; PARIKH, SANJAI J.

2016-01-01

Biochar is increasingly been used as a soil amendment to improve water holding capacity, reduce nutrient leaching, increase soil pH and also as a means to reduce contamination through sorption of heavy metals or organic pollutants. The sorption behavior of three phenylurea herbicides (monuron, diuron, linuron) on five biochars (Enhanced Biochar, Hog Waste, Turkey Litter, Walnut Shell and Wood Feedstock) and an agricultural soil (Yolo silt loam) was investigated using a batch equilibration method. Sorption isotherms of herbicides to biochars were well described by the Freundlich model (R2 = 0.93 -- 0.97). The adsorption KF values ranged from 6.94 to 1306.95 mg kg−1 and indicated the sorption of herbicides in the biochars and Yolo soil was in the sequence of linuron > diuron > monuron and walnut shell biochar > wood feedstock biochar > turkey litter biochar > enhanced biochar > hog waste biochar > Yolo soil. These data show that sorption of herbicides to biochar can have both positive (reduced off-site transport) and negative (reduced herbicide efficacy) implications and specific biochar properties, such as H/C ratio and surface area, should be considered together with soil type, agriculture chemical and climate condition in biochar application to agricultural soil to optimize the system for both agricultural and environmental benefits. PMID:26065514

Emission reduction of 1,3-dichloropropene by soil amendment with biochar

USDA-ARS?s Scientific Manuscript database

Soil fumigation is important for growing many fruits and vegetable crops, but fumigant emissions may contaminate the atmosphere. Biochar as soil amendments has the potential of mitigating climate change effects. In addition, its high surface area and porosity enable it to adsorb or retain nutrients,...

Effects of biochar and other amendments on the physical properties and greenhouse gas emissions of an artificially degraded soil.

PubMed

Mukherjee, A; Lal, R; Zimmerman, A R

2014-07-15

Short and long-term impacts of biochar on soil properties under field conditions are poorly understood. In addition, there is a lack of field reports of the impacts of biochar on soil physical properties, gaseous emissions and C stability, particularly in comparison with other amendments. Thus, three amendments - biochar produced from oak at 650°C, humic acid (HA) and water treatment residual - (WTR) were added to a scalped silty-loam soil @ 0.5% (w/w) in triplicated plots under soybean. Over the 4-month active growing season, all amendments significantly increased soil pH, but the effect of biochar was the greatest. Biochar significantly increased soil-C by 7%, increased sub-nanopore surface area by 15% and reduced soil bulk density by 13% compared to control. However, only WTR amendment significantly increased soil nanopore surface area by 23% relative to the control. While total cumulative CH4 and CO2 emissions were not significantly affected by any amendment, cumulative N2O emission was significantly decreased in the biochar-amended soil (by 92%) compared to control over the growing period. Considering both the total gas emissions and the C removed from the atmosphere as crop growth and C added to the soil, WTR and HA resulted in net soil C losses and biochar as a soil C gain. However, all amendments reduced the global warming potential (GWP) of the soil and biochar addition even produced a net negative GWP effect. The short observation period, low application rate and high intra-treatment variation resulted in fewer significant effects of the amendments on the physicochemical properties of the soils than one might expect indicating further possible experimentation altering these variables. However, there was clear evidence of amendment-soil interaction processes affecting both soil properties and gaseous emissions, particularly for biochar, that might lead to greater changes with additional field emplacement time. Copyright © 2014 Elsevier B.V. All rights reserved.

Role of biochar on composting of organic wastes and remediation of contaminated soils-a review.

PubMed

Wu, Shaohua; He, Huijun; Inthapanya, Xayanto; Yang, Chunping; Lu, Li; Zeng, Guangming; Han, Zhenfeng

2017-07-01

Biochar is produced by pyrolysis of biomass residues under limited oxygen conditions. In recent years, biochar as an amendment has received increasing attention on composting and soil remediation, due to its unique properties such as chemical recalcitrance, high porosity and sorption capacity, and large surface area. This paper provides an overview on the impact of biochar on the chemical characteristics (greenhouse gas emissions, nitrogen loss, decomposition and humification of organic matter) and microbial community structure during composting of organic wastes. This review also discusses the use of biochar for remediation of soils contaminated with organic pollutants and heavy metals as well as related mechanisms. Besides its aging, the effects of biochar on the environment fate and efficacy of pesticides deserve special attention. Moreover, the combined application of biochar and compost affects synergistically on soil remediation and plant growth. Future research needs are identified to ensure a wide application of biochar in composting and soil remediation. Graphical abstract ᅟ.

Turning an environmental problem into an opportunity: potential use of biochar derived from a harmful marine biomass named Cladophora glomerata as anode electrode for Li-ion batteries.

PubMed

Salimi, Pejman; Javadian, Soheila; Norouzi, Omid; Gharibi, Hussein

2017-12-01

The electrochemical performance of lithium ion battery was enhanced by using biochar derived from Cladophora glomerata (C. glomerata) as widespread green macroalgae in most areas of the Iran's Caspian sea coast. By the utilization of the structure of the biochar, micro-/macro-ordered porous carbon with olive-shaped structure was successfully achieved through pyrolysis at 500 °C, which is the optimal temperature for biofuel production, and was activated with HCl. The biochar and HCl treatment biochar (HTB) were applied as anode electrode in lithium ion batteries. Then, electrochemical measurements were conducted on the electrodes via galvanostatic charge-discharge, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) analyses. The electrochemical results indicated a higher specific discharge capacity (700 mAh g -1 ) and good cycling stability for HTB at the current density of 0.1 A g -1 as compared to the biochar. The reason that HTB electrode works better than the biochar could be due to the higher surface area, formation functional groups, removal impurities, and formation some micropores after HCl treatment. The biochar derived from marine biomass and treatment process developed here could provide a promising path for the low-cost, renewable, and environmentally friendly electrode materials. Graphical abstract Algal-biochar into Li-ion Battery.

Comparison of the Physical and Chemical Properties of Laboratory and Field-Aged Biochars.

PubMed

Bakshi, Santanu; Aller, Deborah M; Laird, David A; Chintala, Rajesh

2016-09-01

The long-term impact of biochar on soil properties and agronomic outcomes is influenced by changes in the physical and chemical properties of biochars that occur with time (aging) in soil environments. Fresh biochars, however, are often used in studies because aged biochars are generally unavailable. Therefore, a need exists to develop a method for rapid aging of biochars in the laboratory. The objectives of this study were to compare the physicochemical properties of fresh, laboratory-aged (LA), and field-aged (FA) (≥3 yr) biochars and to assess the appropriateness of a laboratory aging procedure that combines acidification, oxidation, and incubations as a mimic to field aging in neutral or acidic soil environments. Twenty-two biochars produced by fast and slow pyrolysis, and gasification techniques from five different biomass feedstocks (hardwood, corn stover, soybean stover, macadamia nut shells, and switchgrass) were studied. In general, both laboratory and field aging caused similar increases in ash-free volatile matter (% w/w), cation and anion exchange capacities, specific surface area, and modifications in oxygen-containing surface functional groups of the biochars. However, ash content increased for FA (18-195%) and decreased for LA (22-74%) biochars, and pH decreased to a greater extent for LA (2.8-6.7 units) than for FA (1.6-3.8 units) biochars. The results demonstrate that the proposed laboratory aging procedure is effective for predicting the direction of changes in biochar properties on field aging. However, in the future we recommend using a less aggressive acid treatment. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Molecular markers of benzene polycarboxylic acids in describing biochar physiochemical properties and sorption characteristics.

PubMed

Chang, Zhaofeng; Tian, Luping; Wu, Min; Dong, Xudong; Peng, Juan; Pan, Bo

2018-06-01

Biochar function in soil is based on properties such as sorption characteristics, and these are expected to change throughout the life cycle of the biochar. Because biochar particles cannot easily be separated from soil particles, this change is seldom investigated. Biochar-related molecular markers, such as benzene polycarboxylic acids (BPCAs) are promising tools for studying the properties of biochars in complex environmental matrices. In this study, biochars were derived from corn straw and pine wood sawdust at 200-500 °C, and their aging was simulated with NaClO. Biochar properties were characterized by elemental analysis, BET surface characterization and BPCA molecular marker analysis. Chemical oxidation decreased the surface area (SA) but increased the O content of biochars. The oxidation decreased the amount of biochars, with a mass loss in the range of 10-55%. A similar mass loss was also observed for BPCAs and was negatively related to both the pyrolysis temperature and the extent of the condensed structure (higher aromaticity). The biochar amounts were calculated quantitatively using the sum of BPCA contents, with a conversion factor (the ratio of biochar amount to BPCA content) in the range of 3.3-5.5, and were negatively related to the B5CA content. Three model pollutants, namely, bisphenol A (BPA), sulfamethoxazole (SMX), and phenanthrene (PHE), were chosen to study the sorption characteristics of biochar before and after oxidation. Chemical oxidation generally increased SMX sorption but decreased PHE sorption. The nonlinear factor n, based on Freundlich equation modeling, was negatively related to B6CA for all three chemicals. The BPCA molecular markers, especially B5CA and B6CA, were correlated to the biochar properties before and after oxidation and are thus a potentially useful technique for describing the characteristics of biochar in the environment. Copyright © 2018 Elsevier Ltd. All rights reserved.

Adsorption of bovine serum albumin and urease by biochar

NASA Astrophysics Data System (ADS)

Wang, Wenjing; Chen, Lei; Zhang, Yipeng; Liu, Guocheng

2017-04-01

The application of biochar to soil improvement inevitably affects free soil enzymes. However, there is little information on the interaction of soil enzymes with biochar to our knowledge. We thus investigated the adsorption of bovine serum albumin (BSA) and urease onto two biochars from giant reed pyrolyzed at 300 and 600 °C (BCF300 and BCF600). The adsorption amount of BSA and urease on BCF300 and BCF600 was up to 45.6-209 mg/g and 75.3-808 mg/g, respectively, suggesting that the test proteins could be adsorbed onto the biochars effectively. The sorption rate of BSA and urease significantly decreased as the protein concentration increased, suggesting that their adsorption was nonlinear. For the same initial concentration (50 or 200 mg/L), the adsorption amount of BSA on the biochars was lower, only 25.9-60.5% of that of urease. The high specific surface area and hydrophobicity of the biochars may play important roles on the immobilization of the proteins by biochars. These findings will be helpful for better understanding the effects of biochar adding on the soil enzymes.

Biochar from commercially cultivated seaweed for soil amelioration

PubMed Central

Roberts, David A.; Paul, Nicholas A.; Dworjanyn, Symon A.; Bird, Michael I.; de Nys, Rocky

2015-01-01

Seaweed cultivation is a high growth industry that is primarily targeted at human food and hydrocolloid markets. However, seaweed biomass also offers a feedstock for the production of nutrient-rich biochar for soil amelioration. We provide the first data of biochar yield and characteristics from intensively cultivated seaweeds (Saccharina, Undaria and Sargassum – brown seaweeds, and Gracilaria, Kappaphycus and Eucheuma – red seaweeds). While there is some variability in biochar properties as a function of the origin of seaweed, there are several defining and consistent characteristics of seaweed biochar, in particular a relatively low C content and surface area but high yield, essential trace elements (N, P and K) and exchangeable cations (particularly K). The pH of seaweed biochar ranges from neutral (7) to alkaline (11), allowing for broad-spectrum applications in diverse soil types. We find that seaweed biochar is a unique material for soil amelioration that is consistently different to biochar derived from ligno-cellulosic feedstock. Blending of seaweed and ligno-cellulosic biochar could provide a soil ameliorant that combines a high fixed C content with a mineral-rich substrate to enhance crop productivity. PMID:25856799

Biochar from commercially cultivated seaweed for soil amelioration.

PubMed

Roberts, David A; Paul, Nicholas A; Dworjanyn, Symon A; Bird, Michael I; de Nys, Rocky

2015-04-09

Seaweed cultivation is a high growth industry that is primarily targeted at human food and hydrocolloid markets. However, seaweed biomass also offers a feedstock for the production of nutrient-rich biochar for soil amelioration. We provide the first data of biochar yield and characteristics from intensively cultivated seaweeds (Saccharina, Undaria and Sargassum--brown seaweeds, and Gracilaria, Kappaphycus and Eucheuma--red seaweeds). While there is some variability in biochar properties as a function of the origin of seaweed, there are several defining and consistent characteristics of seaweed biochar, in particular a relatively low C content and surface area but high yield, essential trace elements (N, P and K) and exchangeable cations (particularly K). The pH of seaweed biochar ranges from neutral (7) to alkaline (11), allowing for broad-spectrum applications in diverse soil types. We find that seaweed biochar is a unique material for soil amelioration that is consistently different to biochar derived from ligno-cellulosic feedstock. Blending of seaweed and ligno-cellulosic biochar could provide a soil ameliorant that combines a high fixed C content with a mineral-rich substrate to enhance crop productivity.

Biochar from commercially cultivated seaweed for soil amelioration

NASA Astrophysics Data System (ADS)

Roberts, David A.; Paul, Nicholas A.; Dworjanyn, Symon A.; Bird, Michael I.; de Nys, Rocky

2015-04-01

Seaweed cultivation is a high growth industry that is primarily targeted at human food and hydrocolloid markets. However, seaweed biomass also offers a feedstock for the production of nutrient-rich biochar for soil amelioration. We provide the first data of biochar yield and characteristics from intensively cultivated seaweeds (Saccharina, Undaria and Sargassum - brown seaweeds, and Gracilaria, Kappaphycus and Eucheuma - red seaweeds). While there is some variability in biochar properties as a function of the origin of seaweed, there are several defining and consistent characteristics of seaweed biochar, in particular a relatively low C content and surface area but high yield, essential trace elements (N, P and K) and exchangeable cations (particularly K). The pH of seaweed biochar ranges from neutral (7) to alkaline (11), allowing for broad-spectrum applications in diverse soil types. We find that seaweed biochar is a unique material for soil amelioration that is consistently different to biochar derived from ligno-cellulosic feedstock. Blending of seaweed and ligno-cellulosic biochar could provide a soil ameliorant that combines a high fixed C content with a mineral-rich substrate to enhance crop productivity.

Granulation and ferric oxides loading enable biochar derived from cotton stalk to remove phosphate from water.

PubMed

Ren, Jing; Li, Nan; Li, Lei; An, Jing-Kun; Zhao, Lin; Ren, Nan-Qi

2015-02-01

Granulation of biochar powder followed by immobilization of ferric oxides on the macroporous granular biochar (Bg-FO-1) substantially enhanced phosphate removal from water. BET analysis confirmed that both granulation and ferric oxides loading can increase the surface areas and pore volumes effectively. Bg-FO-1 was proven to be a favorable adsorbent for phosphate. The phosphate adsorption capacity was substantially increased from 0 mg/g of raw biochar powder to 0.963 mg/g (Bg-FO-1). When the ferric oxides loading was prior to granulation, the adsorption capacity was decreased by 59-0.399 mg/g, possibly due to the decrease of micropore and mesopore area as well as the overlaying of binders to the activated sites produced by ferric oxides. Copyright © 2014 Elsevier Ltd. All rights reserved.

Biochar prepared from castor oil cake at different temperatures: A voltammetric study applied for Pb(2+), Cd(2+) and Cu(2+) ions preconcentration.

PubMed

Kalinke, Cristiane; Mangrich, Antonio Sálvio; Marcolino-Junior, Luiz H; Bergamini, Márcio F

2016-11-15

Biochar is a carbonaceous material similar produced by pyrolysis of biomass under oxygen-limited conditions. Pyrolysis temperature is an important parameter that can alters biochar characteristics (e.g. surface area, pore size distribution and surface functional groups) and affects it efficacy for adsorption of several probes. In this work, biochar samples have been prepared from castor oil cake using different temperatures of pyrolysis (200-600°C). For the first time, a voltammetric procedure based on carbon paste modified electrode (CPME) was used to investigate the effect of temperature of pyrolysis on the adsorptive characteristics of biochar for Pb(II), Cd(II) and Cu(II) ions. Besides the electrochemical techniques, several characterizations have been performed to evaluate the physicochemical properties of biochar in function of the increase of the pyrolysis temperature. Results suggest that biochar pyrolized at 400°C (BC400) showed a better potential for ions adsorption. The CPME modified with BC400 showed better relative current signal with adsorption affinity: Pb(II)>Cd(II)>Cu(II). Kinetic studies revealed that the pseudo-second order model describes more accurately the adsorption process suggesting that the surface reactions control the adsorption rate. Values found for amount adsorbed were 15.94±0.09; 4.29±0.13 and 2.38±0.39μgg(-1) for Pb(II), Cd(II) and Cu(II) ions, respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

A novel biochar derived from cauliflower (Brassica oleracea L.) roots could remove norfloxacin and chlortetracycline efficiently.

PubMed

Qin, Tingting; Wang, Zhaowei; Xie, Xiaoyun; Xie, Chaoran; Zhu, Junmin; Li, Yan

2017-12-01

The biochar was prepared by pyrolyzing the roots of cauliflowers, at a temperature of 500 °C under oxygen-limited conditions. The structure and characteristics of the biochar were examined using scanning electron microscopy, an energy dispersive spectrometer, a zeta potential analyzer, and Fourier transform infrared spectroscopy. The effects of the temperature, the initial pH, antibiotic concentration, and contact time on the adsorption of norfloxacin (NOR) and chlortetracycline (CTC) onto the biochar were investigated. The adsorption kinetics of NOR and CTC onto the biochar followed the pseudo-second-order kinetic and intra-particle diffusion models. The adsorption isotherm experimental data were well fitted to the Langmuir and Freundlich isotherm models. The maximum adsorption capacities of NOR and CTC were 31.15 and 81.30 mg/g, respectively. There was little difference between the effects of initial solution pH (4.0-10.0) on the adsorption of NOR or CTC onto the biochar because of the buffering effect. The biochar could remove NOR and CTC efficiently in aqueous solutions because of its large specific surface area, abundant surface functional groups, and particular porous structure. Therefore, it could be used as an excellent adsorbent material because of its low cost and high efficiency and the extensive availability of the raw materials.

Using biochar for remediation of soils contaminated with heavy metals and organic pollutants.

PubMed

Zhang, Xiaokai; Wang, Hailong; He, Lizhi; Lu, Kouping; Sarmah, Ajit; Li, Jianwu; Bolan, Nanthi S; Pei, Jianchuan; Huang, Huagang

2013-12-01

Soil contamination with heavy metals and organic pollutants has increasingly become a serious global environmental issue in recent years. Considerable efforts have been made to remediate contaminated soils. Biochar has a large surface area, and high capacity to adsorb heavy metals and organic pollutants. Biochar can potentially be used to reduce the bioavailability and leachability of heavy metals and organic pollutants in soils through adsorption and other physicochemical reactions. Biochar is typically an alkaline material which can increase soil pH and contribute to stabilization of heavy metals. Application of biochar for remediation of contaminated soils may provide a new solution to the soil pollution problem. This paper provides an overview on the impact of biochar on the environmental fate and mobility of heavy metals and organic pollutants in contaminated soils and its implication for remediation of contaminated soils. Further research directions are identified to ensure a safe and sustainable use of biochar as a soil amendment for remediation of contaminated soils.

Removal of phosphate from aqueous solution using magnesium-alginate/chitosan modified biochar microspheres derived from Thalia dealbata.

PubMed

Cui, Xiaoqiang; Dai, Xi; Khan, Kiran Yasmin; Li, Tingqiang; Yang, Xiaoe; He, Zhenli

2016-10-01

The objective of this study was to determine the feasibility of using magnesium-alginate/chitosan modified biochar microspheres to enhance removal of phosphate from aqueous solution. The introduction of MgCl2 substantially increased surface area of biochar (116.2m(2)g(-1)), and both granulation with alginate/chitosan and modification with magnesium improved phosphate sorption on the biochars. Phosphate sorption on the biochars could be well described by a simple Langmuir model, and the MgCl2-alginate modified biochar microspheres exhibited the highest phosphate sorption capacity (up to 46.56mgg(-1)). The pseudo second order kinetic model better fitted the kinetic data, and both the Yoon-Nelson and Thomas models were superior to other models in describing phosphate dynamic sorption. Precipitation with minerals and ligand exchange were the possible mechanisms of phosphate sorption on the modified biochars. These results imply that MgCl2-alginate modified biochar microspheres have potential as a green cost-effective sorbent for remediating P contaminated water environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Physical and chemical characterization of biochars derived from different agricultural residues

NASA Astrophysics Data System (ADS)

Jindo, K.; Mizumoto, H.; Sawada, Y.; Sanchez-Monedero, M. A.; Sonoki, T.

2014-12-01

Biochar is widely recognized as an efficient tool for carbon sequestration and soil fertility. The understanding of its chemical and physical properties, which are strongly related to the type of the initial material used and pyrolysis conditions, is crucial to identify the most suitable application of biochar in soil. A selection of organic wastes with different characteristics (e.g., rice husk (RH), rice straw (RS), wood chips of apple tree (Malus pumila) (AB), and oak tree (Quercus serrata) (OB)) were pyrolyzed at different temperatures (400, 500, 600, 700, and 800 °C) in order to optimize the physicochemical properties of biochar as a soil amendment. Low-temperature pyrolysis produced high biochar yields; in contrast, high-temperature pyrolysis led to biochars with a high C content, large surface area, and high adsorption characteristics. Biochar obtained at 600 °C leads to a high recalcitrant character, whereas that obtained at 400 °C retains volatile and easily labile compounds. The biochar obtained from rice materials (RH and RS) showed a high yield and unique chemical properties because of the incorporation of silica elements into its chemical structure. The biochar obtained from wood materials (AB and OB) showed high carbon content and a high absorption character.

A novel approach in organic waste utilization through biochar addition in wood/polypropylene composites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Das, Oisik; Sarmah, Ajit K., E-mail: a.sarmah@auckland.ac.nz; Bhattacharyya, Debes

Highlights: • Biochar made from waste wood was added with wood polypropylene composites. • 24% biochar gave the best mechanical properties. • 6% biochar had no effect on physico-mechanical properties of composites. • Coupling agent remained unreacted in composites having higher amount of biochar. - Abstract: In an attempt to concurrently address the issues related to landfill gas emission and utilization of organic wastes, a relatively novel idea is introduced to develop biocomposites where biochar made from pyrolysis of waste wood (Pinus radiata) is added with the same wood, plastic/polymer (polypropylene) and maleated anhydride polypropylene (MAPP). Experiments were conducted bymore » manufacturing wood and polypropylene composites (WPCs) mixed with 6 wt%, 12 wt%, 18 wt%, 24 wt%, and 30 wt% biochar. Though 6 wt% addition had similar properties to that of the control (composite without biochar), increasing biochar content to 24 wt% improved the composite’s tensile/flexural strengths and moduli. The biochar, having high surface area due to fine particles and being highly carbonised, acted as reinforcing filler in the biocomposite. Composites having 12 wt% and 18 wt% of biochar were found to be the most ductile and thermally stable, respectively. This study demonstrates that, WPCs added with biochar has good potential to mitigate wastes while simultaneously producing biocomposites having properties that might be suited for various end applications.« less

Biochars impact on soil moisture storage in an Ultisol and two Aridisols

DOE Office of Scientific and Technical Information (OSTI.GOV)

Novak, Jeffrey M.; Busscher, Warren J.; Watts, Don W.

2012-05-31

Biochar additions to soils can improve soil water storage capability, however, there is sparse information identifying feedstocks and pyrolysis conditions that maximize this improvement. Nine biochars were pyrolyzed from five feedstocks at two temperatures and their physical and chemical properties were characterized. Biochars were mixed at 2% wt w{sup -1} into a Norfolk loamy sand (Fine-loamy, kaolinitic, thermic Typic Kandiudult), a Declo silt loam (Coarse-loamy, mixed, superactive, mesic xeric Haplocalcid), or a Warden silt loam (Coarse-silty, mixed, superactive, mesic xeric Haplocambid). Untreated soils served as controls. Soils were laboratory incubated in pots for 127 days and were leached about everymore » 30 days with deionized water. Soil bulk densities were measured before each leaching event. For six days thereafter, pot holding capacities (PHC) for water were determined gravimetrically and were used as a surrogate for soil moisture contents. Water tension curves were also measured on the biochar treated and untreated Norfolk soil. Biochar surface area, surface tension, ash, C, and Si contents, in general, increased when produced under higher pyrolytic temperatures ({ge}500 C). Both switchgrass biochars caused the most significant water PHC improvements in the Norfolk, Declo and Warden soils compared to the controls. Norfolk soil water tension results at 5 and 60 kPa corroborated that biochar from switchgrass caused the most significant moisture storage improvements. Significant correlation occurred between the PHC for water with soil bulk densities. In general, biochar amendments enhanced the moisture storage capacity of Ultisols and Aridisols, but the effect varied with feedstock selection and pyrolysis temperature.« less

Localization of heavy metals immobilized on specific organic and mineral parts of a wood-derived biochar

NASA Astrophysics Data System (ADS)

Rees, Frédéric; Watteau, Françoise; Morel, Jean-Louis

2013-04-01

Biochar has been intensively investigated over recent years, not only as a promising carbon sequestration or fertilizing agent in soils but also as a possible new sorbent to remediate contaminated soils. A few studies have revealed its high potential for heavy metals immobilization depending on the nature of biochar and trace elements. The mechanisms behind this immobilization remain however unclear: some authors have hypothesized a high sorption capacity due to biochar large surface area while others have suggested that this immobilization is mainly due to soil pH increase. In particular, the distinction between heavy metals specific sorption in biochar pores and heavy metals precipitation in or outside biochar particles is often impossible to make while it is of primary importance to evaluate biochar ability to retain these pollutants on a long-time scale. In order to evaluate the main heavy metal immobilization effects on a standard biochar and to identify the most successful biochar parts of the sample, we examined biochar particles after heavy metals immobilization in batch experiments designed to mimic real chemical processes in soils. A biochar derived from hard and soft wood and pyrolyzed at about 450°C was put in contact with relatively low concentrations of heavy metals (Pb, Cu, Cd, Zn, Ni) in an initially acidic Ca(NO3)2 solution. Following a one-week adsorption and a one-week desorption step, we recovered the biochar particles and observed them using scanning electron microscopy coupled to energy dispersive x-ray spectroscopy, focusing especially on the changes in mineral phases and the location of each of the retained heavy metals on biochar particles. We were able to distinguish different structures in the biochar samples which were linked to the degree of pyrolysis and the exact nature of the raw wood biomass. We detected the presence of concentrated metals zones (e.g. lead) in specific locations of the organic particles depending on the original plant tissues, and enlightened metal associations with newly-formed mineral phases such as calcite present on biochar surface. These observations provide new insights in the understanding of metal immobilization mechanisms on biochar such as precipitation and co-precipitation. Our findings also underline the need to consider the heterogeneity of biochar constitution for optimizing the remediation potential of biochar on contaminated sites.

Biochar: a green sorbent to sequester acidic organic contaminants

NASA Astrophysics Data System (ADS)

Sigmund, Gabriel; Kah, Melanie; Sun, Huichao; Hofmann, Thilo

2015-04-01

Biochar is a carbon rich product of biomass pyrolysis that exhibits a high sorption potential towards a wide variety of inorganic and organic contaminants. Because it is a valuable soil additive and a potential carbon sink that can be produced from renewable resources, biochar has gained growing attention for the development of more sustainable remediation strategies. A lot of research efforts have been dedicated to the sorption of hydrophobic contaminants and metals to biochar. Conversely, the understanding of the sorption of acidic organic contaminants remains limited, and questions remain on the influence of biochar characteristics (e.g. ash content) on the sorption behaviour of acidic organic contaminants. To address this knowledge gap, sorption batch experiments were conducted with a series of structurally similar acidic organic contaminants covering a range of dissociation constant (2,4-D, MCPA, 2,4-DB and triclosan). The sorbents selected for experimentation included a series of 10 biochars covering a range of characteristics, multiwalled carbon nanotubes as model for pure carbonaceous phases, and an activated carbon as benchmark. Overall, sorption coefficient [L/kg] covered six orders of magnitude and generally followed the order 2,4-D < MCPA < 2,4-DB < triclosan. Combining comprehensive characterization of the sorbents with the sorption dataset allowed the discussion of sorption mechanisms and driving factors of sorption. Statistical analysis suggests that (i) partitioning was the main driver for sorption to sorbents with small specific surface area (< 25 m²/g), whereas (ii) specific mechanisms dominated sorption to sorbents with larger specific surface area. Results showed that factors usually not considered for the sorption of neutral contaminants play an important role for the sorption of organic acids. The pH dependent lipophilicity ratio (i.e. D instead of Kow), ash content and ionic strength are key factors influencing the sorption of acidic organic contaminants to biochars. Overall, the identified factors, as well as the environmental matrix, should be carefully considered when selecting the type of biochar for sequestration purposes.

Adsorption of naphthenic acids on high surface area activated carbons.

PubMed

Iranmanesh, Sobhan; Harding, Thomas; Abedi, Jalal; Seyedeyn-Azad, Fakhry; Layzell, David B

2014-01-01

In oil sands mining extraction, water is an essential component; however, the processed water becomes contaminated through contact with the bitumen at high temperature, and a portion of it cannot be recycled and ends up in tailing ponds. The removal of naphthenic acids (NAs) from tailing pond water is crucial, as they are corrosive and toxic and provide a substrate for microbial activity that can give rise to methane, which is a potent greenhouse gas. In this study, the conversion of sawdust into an activated carbon (AC) that could be used to remove NAs from tailings water was studied. After producing biochar from sawdust by a slow-pyrolysis process, the biochar was physically activated using carbon dioxide (CO2) over a range of temperatures or prior to producing biochar, and the sawdust was chemically activated using phosphoric acid (H3PO4). The physically activated carbon had a lower surface area per gram than the chemically activated carbon. The physically produced ACs had a lower surface area per gram than chemically produced AC. In the adsorption tests with NAs, up to 35 mg of NAs was removed from the water per gram of AC. The chemically treated ACs showed better uptake, which can be attributed to its higher surface area and increased mesopore size when compared with the physically treated AC. Both the chemically produced and physically produced AC provided better uptake than the commercially AC.

Effects of different types of biochar on methane and ammonia mitigation during layer manure composting.

PubMed

Chen, Wei; Liao, Xindi; Wu, Yinbao; Liang, Juan Boo; Mi, Jiandui; Huang, Jinjie; Zhang, Heng; Wu, Yu; Qiao, Zhifen; Li, Xi; Wang, Yan

2017-03-01

Biochar, because of its unique physiochemical properties and sorption capacity, may be an ideal amendment in reducing gaseous emissions during composting process but there has been little information on the potential effects of different types of biochar on undesired gaseous emissions. The objective of this study was to examine the ability and mechanism of different types of biochar, as co-substrate, in mitigating gaseous emission from composting of layer hen manure. The study was conducted in small-scale laboratory composters with the addition of 10% of one of the following biochars: cornstalk biochar, bamboo biochar, woody biochar, layer manure biochar and coir biochar. The results showed that the cumulative NH 3 production was significantly reduced by 24.8±2.9, 9.2±1.3, 20.1±2.6, 14.2±1.6, 11.8±1.7% (corrected for initial total N) in the cornstalk biochar, bamboo biochar, woody biochar, layer manure biochar and coir biochar treatments, respectively, compared to the control. Total CH 4 emissions was significantly reduced by 26.1±2.3, 15.5±2.1, 22.4±3.1, 17.1±2.1% (corrected for the initial total carbon) for cornstalk biochar, bamboo biochar, woody biochar and coir biochar treatments than the control. Moreover, addition of cornstalk biochar increased the temperature and NO 3 - -N concentration and decreased the pH, NH 4 + -N and organic matter content throughout the composting process. The results suggested that total volatilization of NH 3 and CH 4 in cornstalk biochar treatment was lower than the other treatments; which could be due to (i) decrease of pH and higher nitrification, (ii) high sorption capacity for gases and their precursors, such as ammonium nitrogen from composting mixtures, because of the higher surface area, pore volumes, total acidic functional groups and CEC of cornstalk biochar. Copyright © 2017 Elsevier Ltd. All rights reserved.

Magnetic biochar combining adsorption and separation recycle for removal of chromium in aqueous solution.

PubMed

Xin, Ouyang; Yitong, Han; Xi, Cao; Jiawei, Chen

2017-03-01

Biochar has been developed in recent years for the removal of contaminants such as Cr (VI) in water. The enhancement of the adsorption capacity of biochar and its recyclable use are still challenges. In this study, magnetic biochar derived from corncobs and peanut hulls was synthesized under different pyrolysis temperatures after pretreating the biomass with a low concentration of 0.5 M FeCl 3 solution. The morphology, specific surface area, saturation magnetization and Fourier transform infrared spectroscopy (FT-IR) spectra were characterized for biochar. The magnetic biochar performed well in combining adsorption and separation recycle for the removal of Cr (VI) in water. The Cr (VI) adsorbance of the biochar was increased with the increase in pyrolysis temperature, and the magnetic biochar derived from corncobs showed better performance for both magnetization and removal of Cr (VI) than that from peanut hulls. The Langmuir model was used for the isothermal adsorption and the maximum Cr (VI) adsorption capacity of corncob magnetic biochar pyrolyzed at 650 °C reached 61.97 mg/g. An alkaline solution (0.1 M NaOH) favored the desorption of Cr (VI) from the magnetic biochar, and the removal of Cr (VI) still remained around 77.6% after four cycles of adsorption-desorption. The results showed that corncob derived magnetic biochar is a potentially efficient and recoverable adsorbent for remediation of heavy metals in water.

Microwave-assisted preparation of nitrogen-doped biochars by ammonium acetate activation for adsorption of acid red 18

NASA Astrophysics Data System (ADS)

Wang, Li; Yan, Wei; He, Chi; Wen, Hang; Cai, Zhang; Wang, Zixuan; Chen, Zhengzheng; Liu, Weifeng

2018-03-01

Nitrogen-doped biochars derived from Phragmites australis (PA) were prepared using ammonium chloride (AC) and ammonium acetate (AA) as nitrogen sources by phosphoric acid activation via microwave assisted treatment. Their physicochemical properties, acid red 18 (AR18) adsorption performance and possible mechanisms were systematically evaluated. Nitrogen was successfully doped onto the biochar's surface in the formation of pyrrole-N, pyridine-N and oxidized-N with pyridine-N being the major component (64%). The pHiep and basic foundational groups of the biochars increased consequently however their surface areas slightly decreased. The adsorption kinetic data were best fit to the pseudo-second order model and the equilibrium data were well simulated by Freundlich model for all biochars, indicating the important role of chemical interactions. The maximum AR18 adsorption capacities of PAB-AA and PAB-AC were 1.41 and 1.18 times higher compared with the non N-doped biochar, which were mainly attributed to the π-π EDA interaction between the pyridine-N and AR18 as revealed by the comparison of XPS analyses before and after AR18 adsorption. Meanwhile, other mechanisms such as pore filling effect, Lewis acid-base interaction, electrostatic attraction and hydrogen bonding also existed as demonstrated by BET, XPS and FTIR analyses.

Thermodynamic Analysis of Nickel(II) and Zinc(II) Adsorption to Biochar.

PubMed

Alam, Md Samrat; Gorman-Lewis, Drew; Chen, Ning; Flynn, Shannon L; Ok, Yong Sik; Konhauser, Kurt O; Alessi, Daniel S

2018-05-21

While numerous studies have investigated metal uptake from solution by biochar, few of these have developed a mechanistic understanding of the adsorption reactions that occur at the biochar surface. In this study, we explore a combined modeling and spectroscopic approach for the first time to describe the molecular level adsorption of Ni(II) and Zn(II) to five types of biochar. Following thorough characterization, potentiometric titrations were carried out to measure the proton (H + ) reactivity of each biochar, and the data was used to develop protonation models. Surface complexation modeling (SCM) supported by synchrotron-based extended X-ray absorption fine structure (EXAFS) was then used to gain insights into the molecular scale metal-biochar surface reactions. The SCM approach was combined with isothermal titration calorimetry (ITC) data to determine the thermodynamic driving forces of metal adsorption. Our results show that the reactivity of biochar toward Ni(II) and Zn(II) directly relates to the site densities of biochar. EXAFS along with FT-IR analyses, suggest that Ni(II) and Zn(II) adsorption occurred primarily through proton-active carboxyl (-COOH) and hydroxyl (-OH) functional groups on the biochar surface. SCM-ITC analyses revealed that the enthalpies of protonation are exothermic and Ni(II) and Zn(II) complexes with biochar surface are slightly exothermic to slightly endothermic. The results obtained from these combined approaches contribute to the better understanding of molecular scale metal adsorption onto the biochar surface, and will facilitate the further development of thermodynamics-based, predictive approaches to biochar removal of metals from contaminated water.

Properties of biochar-amended soils and their sorption of imidacloprid, isoproturon, and atrazine.

PubMed

Jin, Jie; Kang, Mingjie; Sun, Ke; Pan, Zezhen; Wu, Fengchang; Xing, Baoshan

2016-04-15

Biochars produced from rice straw, wheat straw and swine manure at 300, 450 and 600°C were added to soil at 1, 5, 10, or 20% levels to determine whether they would predictably reduce the pore water concentration of imidacloprid, isoproturon, and atrazine. The sorption capacity of the mixtures increased with increasing biochar amounts. The enhanced sorption capacity could be attributed to the increased organic carbon (OC) content and surface area (SA) as well as the decreased hydrophobicity. Biochar dominated the overall sorption when its content was above 5%. The OC contents of the mixtures with 10% and 20% biochar were generally lower than the predicted values. This implies possible interaction between soil components and biochar and/or the effect of biochar oxidation. For soils amended with biochars produced at 300°C, the N2 SA (N2-SA) values were underestimated. The predicted CO2 SA (CO2-SA) values of the mixtures at the biochar content of 10% and 20% were generally higher than the experimental values. Sorption of imidacloprid to the soils amended with biochar at 10% and 20% levels, excluding the soils amended with rice (SR300) and wheat (SW300) straw-derived biochar produced at 300°C, was lower than the predicted value. For SR300 and SW300, the intrinsic sorption capacity of biochar was enhanced by 1.3-5.6 times, depending on the biochar, solute concentration, and biochar dose. This study indicates that biochars would be helpful to stabilize the soil contaminated with imidacloprid, isoproturon, and atrazine, but the sorption capacity of the mixtures could exceed or fall short of predicted values without assuming a cross-effect between soil and biochar. Copyright © 2016 Elsevier B.V. All rights reserved.

Effect of pyrolysis temperature on polycyclic aromatic hydrocarbons toxicity and sorption behaviour of biochars prepared by pyrolysis of paper mill effluent treatment plant sludge.

PubMed

Devi, Parmila; Saroha, Anil K

2015-09-01

The polycyclic aromatic hydrocarbons (PAHs) toxicity and sorption behaviour of biochars prepared from pyrolysis of paper mill effluent treatment plant (ETP) sludge in temperature range 200-700 °C was studied. The sorption behaviour was found to depend on the degree of carbonization where the fractions of carbonized and uncarbonized organic content in the biochar act as an adsorption media and partition media, respectively. The sorption and partition fractions were quantified by isotherm separation method and isotherm parameters were correlated with biochar properties (aromaticity, polarity, surface area, pore volume and ash content). The risk assessment for the 16 priority EPA PAHs present in the biochar matrix was performed and it was found that the concentrations of the PAHs in the biochar were within the permissible limits prescribed by US EPA (except BC400 and BC500 for high molecular weight PAHs). Copyright © 2015 Elsevier Ltd. All rights reserved.

Adsorption of acid-extractable organics from oil sands process-affected water onto biomass-based biochar: Metal content matters.

PubMed

Bhuiyan, Tazul I; Tak, Jin K; Sessarego, Sebastian; Harfield, Don; Hill, Josephine M

2017-02-01

The impact of biochar properties on acid-extractable organics (AEO) adsorption from oil sands process-affected water (OSPW) was studied. Biochar from wheat straw with the highest ash content (14%) had the highest adsorption capacity (0.59 mg/g) followed by biochar from pulp mill sludge, switchgrass, mountain pine, hemp shives, and aspen wood. The adsorption capacity had no obvious trend with surface area, total pore volume, bulk polarity and aromaticity. The large impact of metal content was consistent with the carboxylates (i.e., naphthenate species) in the OSPW binding to the metals (mainly Al and Fe) on the carbon substrate. Although the capacity of biochar is still approximately two orders of magnitude lower than that of a commercial activated carbon, confirming the property (i.e., metal content) that most influenced AEO adsorption, may allow biochar to become competitive with activated carbon after normalizing for cost, especially if this cost includes environmental impacts. Copyright © 2016 Elsevier Ltd. All rights reserved.

Removal of Congo Red and Methylene Blue from Aqueous Solutions by Vermicompost-Derived Biochars.

PubMed

Yang, Gang; Wu, Lin; Xian, Qiming; Shen, Fei; Wu, Jun; Zhang, Yanzong

2016-01-01

Biochars, produced by pyrolyzing vermicompost at 300, 500, and 700°C were characterized and their ability to adsorb the dyes Congo red (CR) and Methylene blue (MB) in an aqueous solution was investigated. The physical and chemical properties of biochars varied significantly based on the pyrolysis temperatures. Analysis of the data revealed that the aromaticity, polarity, specific surface area, pH, and ash content of the biochars increased gradually with the increase in pyrolysis temperature, while the cation exchange capacity, and carbon, hydrogen, nitrogen and oxygen contents decreased. The adsorption kinetics of CR and MB were described by pseudo-second-order kinetic models. Both of Langmuir and Temkin model could be employed to describe the adsorption behaviors of CR and MB by these biochars. The biochars generated at higher pyrolysis temperature displayed higher CR adsorption capacities and lower MB adsorption capacities than those compared with the biochars generated at lower pyrolysis temperatures. The biochar generated at the higher pyrolytic temperature displayed the higher ability to adsorb CR owing to its promoted aromaticity, and the cation exchange is the key factor that positively affects adsorption of MB.

Removal of Congo Red and Methylene Blue from Aqueous Solutions by Vermicompost-Derived Biochars

PubMed Central

Yang, Gang; Wu, Lin; Xian, Qiming; Shen, Fei; Wu, Jun; Zhang, Yanzong

2016-01-01

Biochars, produced by pyrolyzing vermicompost at 300, 500, and 700°C were characterized and their ability to adsorb the dyes Congo red (CR) and Methylene blue (MB) in an aqueous solution was investigated. The physical and chemical properties of biochars varied significantly based on the pyrolysis temperatures. Analysis of the data revealed that the aromaticity, polarity, specific surface area, pH, and ash content of the biochars increased gradually with the increase in pyrolysis temperature, while the cation exchange capacity, and carbon, hydrogen, nitrogen and oxygen contents decreased. The adsorption kinetics of CR and MB were described by pseudo-second-order kinetic models. Both of Langmuir and Temkin model could be employed to describe the adsorption behaviors of CR and MB by these biochars. The biochars generated at higher pyrolysis temperature displayed higher CR adsorption capacities and lower MB adsorption capacities than those compared with the biochars generated at lower pyrolysis temperatures. The biochar generated at the higher pyrolytic temperature displayed the higher ability to adsorb CR owing to its promoted aromaticity, and the cation exchange is the key factor that positively affects adsorption of MB. PMID:27144922

Sorption of pure N2O to biochars and other organic and inorganic materials under anhydrous conditions

USGS Publications Warehouse

Cornelissen, Gerard; Rutherford, David W.; Arp, Hans Peter H.; Dorsch, Peter; Kelly, Charlene N.; Rostad, Colleen E.

2013-01-01

Suppression of nitrous oxide (N2O) emissions from soil is commonly observed after amendment with biochar. The mechanisms accounting for this suppression are not yet understood. One possible contributing mechanism is N2O sorption to biochar. The sorption of N2O and carbon dioxide (CO2) to four biochars was measured in an anhydrous system with pure N2O. The biochar data were compared to those for two activated carbons and other components potentially present in soils—uncharred pine wood and peat—and five inorganic metal oxides with variable surface areas. Langmuir maximum sorption capacities (Qmax) for N2O on the pine wood biochars (generated between 250 and 500 °C) and activated carbons were 17–73 cm3 g–1 at 20 °C (median 51 cm3 g–1), with Langmuir affinities (b) of 2–5 atm–1 (median 3.4 atm–1). Both Qmaxand b of the charred materials were substantially higher than those for peat, uncharred wood, and metal oxides [Qmax 1–34 cm3 g–1 (median 7 cm3 g–1); b 0.4–1.7 atm–1 (median 0.7 atm–1)]. This indicates that biochar can bind N2O more strongly than both mineral and organic soil materials. Qmax and b for CO2 were comparable to those for N2O. Modeled sorption coefficients obtained with an independent polyparameter—linear free-energy relationship matched measured data within a factor 2 for mineral surfaces but underestimated by a factor of 5–24 for biochar and carbonaceous surfaces. Isosteric enthalpies of sorption of N2O were mostly between −20 and −30 kJ mol–1, slightly more exothermic than enthalpies of condensation (−16.1 kJ mol–1). Qmax of N2O on biochar (50000–130000 μg g–1 biochar at 20 °C) exceeded the N2O emission suppressions observed in the literature (range 0.5–960 μg g–1 biochar; median 16 μg g–1) by several orders of magnitude. Thus, the hypothesis could not be falsified that sorption of N2O to biochar is a mechanism of N2O emission suppression.

Evaluation of Varying Biochars as Carrier Materials for Bacterial Soil Inoculants

NASA Astrophysics Data System (ADS)

Hale, Lauren; Crowley, David

2014-05-01

The incorporation of biochar into agricultural soils for carbon sequestration and improved soil fertility creates an opportunity to simultaneously deliver plant-growth promoting rhizobacteria (PGPR). Many characteristics of biochar materials indicate that these particles could be conducive as inoculum carriers. This could provide a value-added component for biochar marketing and has an advantage over traditional carrier materials, which can be unsustainable or expensive to produce. Here, we assessed the suitability of 10 biochar types, made from 5 feedstocks at 2 pyrolysis temperatures (300°C and 600°C), to serve as carriers for 2 model PGPR strains, Enterobacter cloacae UW5 and Pseudomonas putida UW4. All biochars were characterized based on BET specific surface area, C-N content, pH, EC, and their abilities to adsorb bacterial cells from a liquid inoculum. Further studies incorporated qPCR to quantify the survival of inoculants after introduction into soils via biochar carriers. The biochars that performed well were further assayed for their influence on PGPR traits, 1-aminocyclopropane-1-carboxylate (ACC) deaminase and auxin production. Peat and vermiculite served as traditional carrier materials to which we compared the biochars. Our findings indicated that biochars varied in their interactions with our model PGPR strains. Based on our analysis several biochar types were able to serve as carriers which were as good, if not better than, the traditional carrier materials. Future work should seek to assess shelf life and varying inoculation methods for the biochar-inoculant complexes.

Toward the Standardization of Biochar Analysis: The COST Action TD1107 Interlaboratory Comparison.

PubMed

Bachmann, Hans Jörg; Bucheli, Thomas D; Dieguez-Alonso, Alba; Fabbri, Daniele; Knicker, Heike; Schmidt, Hans-Peter; Ulbricht, Axel; Becker, Roland; Buscaroli, Alessandro; Buerge, Diane; Cross, Andrew; Dickinson, Dane; Enders, Akio; Esteves, Valdemar I; Evangelou, Michael W H; Fellet, Guido; Friedrich, Kevin; Gasco Guerrero, Gabriel; Glaser, Bruno; Hanke, Ulrich M; Hanley, Kelly; Hilber, Isabel; Kalderis, Dimitrios; Leifeld, Jens; Masek, Ondrej; Mumme, Jan; Carmona, Marina Paneque; Calvelo Pereira, Roberto; Rees, Frederic; Rombolà, Alessandro G; de la Rosa, José Maria; Sakrabani, Ruben; Sohi, Saran; Soja, Gerhard; Valagussa, Massimo; Verheijen, Frank; Zehetner, Franz

2016-01-20

Biochar produced by pyrolysis of organic residues is increasingly used for soil amendment and many other applications. However, analytical methods for its physical and chemical characterization are yet far from being specifically adapted, optimized, and standardized. Therefore, COST Action TD1107 conducted an interlaboratory comparison in which 22 laboratories from 12 countries analyzed three different types of biochar for 38 physical-chemical parameters (macro- and microelements, heavy metals, polycyclic aromatic hydrocarbons, pH, electrical conductivity, and specific surface area) with their preferential methods. The data were evaluated in detail using professional interlaboratory testing software. Whereas intralaboratory repeatability was generally good or at least acceptable, interlaboratory reproducibility was mostly not (20% < mean reproducibility standard deviation < 460%). This paper contributes to better comparability of biochar data published already and provides recommendations to improve and harmonize specific methods for biochar analysis in the future.

Engineering Biochar Hydrophobicity to Mitigate Risk of Top-Soil Erosion

NASA Astrophysics Data System (ADS)

Kinney, T. J.; Dean, M. R.; Hockaday, W. C.; Masiello, C. A.

2009-12-01

The pyrolysis of biomass is a net carbon negative method of sequestering atmospheric carbon as recalcitrant black carbon. The resulting solid product, called biochar, is likely to improve agricultural soils when used as a soil conditioner in sustainable land management practice. Biochar has been shown to improve crop yields, improve water-holding capacity in sandy soils, increase cation exchange capacity (CEC), and retain nutrients from fertilization longer than soils unamended with biochar. Biochar undoubtedly has high potential as both a carbon management tool and a tool to increase global food production. However, little is understood about possible side effects of biochar in agricultural soils such as ecosystem toxicity, interactions with biota, and modification of soil hydrologic properties, such as permeability. The hydrophobicity of a soil determines how easily precipitation can permeate soil pores. Water that fails to permeate is redirected as runoff, responsible for the detachment and transport of nutrient-rich topsoil particles. Mitigating top-soil erosion is an important aspect of sustainable land management. Biochar, primarily composed of condensed aromatic structures, is a hydrophobic material and incorporating it into agricultural soils may act to alter soil hydrology through multiple avenues. These include a likely increase in soil water-holding capacity (a positive outcome) and a potential increase in soil hydrophobicity (a negative outcome). In an effort to understand how to engineer reduced biochar hydrophobicity, we investigated the hydrophobicity of biochars as a function of biomass feedstock, pyrolysis temperatures, and post-pyrolysis chemical treatments. We used Water Drop Penetration Time (WDPT) and Molarity of an Ethanol Drop (MED) tests to measure hydrophobicity, and FTIR, CPMAS-NMR, and N2-BET to probe the surface chemistry, bulk chemistry, and surface area of various biochars, respectively. We used post-pyrolysis chemical treatments of biochar to study the origin of biochar hydrophobicity and to assess the possibility of reducing hydrophobicity prior to soil amendment. We used correlative analysis to study the relationship between hydrophobicity, biomass and pyrolysis characteristics, as well as chemical treatments. Future work will focus on engineering designer biochars which minimize hydrophobicity while maximizing positive benefits, such as ion exchange capacity.

Removal of Zinc from Aqueous Solution by Optimized Oil Palm Empty Fruit Bunches Biochar as Low Cost Adsorbent

PubMed Central

Salleh, M. A. Mohd; Asady, Bahareh

2017-01-01

This study aims to produce optimized biochar from oil palm empty fruit bunches (OPEFB), as a green, low cost adsorbent for uptake of zinc from aqueous solution. The impact of pyrolysis conditions, namely, highest treatment temperature (HTT), heating rate (HR), and residence time (RT) on biochar yield and adsorption capacity towards zinc, was investigated. Mathematical modeling and optimization of independent variables were performed employing response surface methodology (RSM). HTT was found to be the most influential variable, followed by residence time and heating rate. Based on the central composite design (CCD), two quadratic models were developed to correlate three independent variables to responses. The optimum production condition for OPEFB biochar was found as follows: HTT of 615°C, HR of 8°C/min, and RT of 128 minutes. The optimum biochar showed 15.18 mg/g adsorption capacity for zinc and 25.49% of yield which was in agreement with the predicted values, satisfactory. Results of the characterization of optimum product illustrated well-developed BET surface area and porous structure in optimum product which favored its sorptive ability. PMID:28420949

Biochar from sugarcane filtercake reduces soil CO2 emissions relative to raw residue and improves water retention and nutrient availability in a highly-weathered tropical soil.

PubMed

Eykelbosh, Angela Joy; Johnson, Mark S; Santos de Queiroz, Edmar; Dalmagro, Higo José; Guimarães Couto, Eduardo

2014-01-01

In Brazil, the degradation of nutrient-poor Ferralsols limits productivity and drives agricultural expansion into pristine areas. However, returning agricultural residues to the soil in a stabilized form may offer opportunities for maintaining or improving soil quality, even under conditions that typically promote carbon loss. We examined the use of biochar made from filtercake (a byproduct of sugarcane processing) on the physicochemical properties of a cultivated tropical soil. Filtercake was pyrolyzed at 575°C for 3 h yielding a biochar with increased surface area and porosity compared to the raw filtercake. Filtercake biochar was primarily composed of aromatic carbon, with some residual cellulose and hemicellulose. In a three-week laboratory incubation, CO2 effluxes from a highly weathered Ferralsol soil amended with 5% biochar (dry weight, d.w.) were roughly four-fold higher than the soil-only control, but 23-fold lower than CO2 effluxes from soil amended with 5% (d.w.) raw filtercake. We also applied vinasse, a carbon-rich liquid waste from bioethanol production typically utilized as a fertilizer on sugarcane soils, to filtercake- and biochar-amended soils. Total CO2 efflux from the biochar-amended soil in response to vinasse application was only 5% of the efflux when vinasse was applied to soil amended with raw filtercake. Furthermore, mixtures of 5 or 10% biochar (d.w.) in this highly weathered tropical soil significantly increased water retention within the plant-available range and also improved nutrient availability. Accordingly, application of sugarcane filtercake as biochar, with or without vinasse application, may better satisfy soil management objectives than filtercake applied to soils in its raw form, and may help to build soil carbon stocks in sugarcane-cultivating regions.

Biochar from Sugarcane Filtercake Reduces Soil CO2 Emissions Relative to Raw Residue and Improves Water Retention and Nutrient Availability in a Highly-Weathered Tropical Soil

PubMed Central

Eykelbosh, Angela Joy; Johnson, Mark S.; Santos de Queiroz, Edmar; Dalmagro, Higo José; Guimarães Couto, Eduardo

2014-01-01

In Brazil, the degradation of nutrient-poor Ferralsols limits productivity and drives agricultural expansion into pristine areas. However, returning agricultural residues to the soil in a stabilized form may offer opportunities for maintaining or improving soil quality, even under conditions that typically promote carbon loss. We examined the use of biochar made from filtercake (a byproduct of sugarcane processing) on the physicochemical properties of a cultivated tropical soil. Filtercake was pyrolyzed at 575°C for 3 h yielding a biochar with increased surface area and porosity compared to the raw filtercake. Filtercake biochar was primarily composed of aromatic carbon, with some residual cellulose and hemicellulose. In a three-week laboratory incubation, CO2 effluxes from a highly weathered Ferralsol soil amended with 5% biochar (dry weight, d.w.) were roughly four-fold higher than the soil-only control, but 23-fold lower than CO2 effluxes from soil amended with 5% (d.w.) raw filtercake. We also applied vinasse, a carbon-rich liquid waste from bioethanol production typically utilized as a fertilizer on sugarcane soils, to filtercake- and biochar-amended soils. Total CO2 efflux from the biochar-amended soil in response to vinasse application was only 5% of the efflux when vinasse was applied to soil amended with raw filtercake. Furthermore, mixtures of 5 or 10% biochar (d.w.) in this highly weathered tropical soil significantly increased water retention within the plant-available range and also improved nutrient availability. Accordingly, application of sugarcane filtercake as biochar, with or without vinasse application, may better satisfy soil management objectives than filtercake applied to soils in its raw form, and may help to build soil carbon stocks in sugarcane-cultivating regions. PMID:24897522

Preparation and characterization of a novel graphene/biochar composite for aqueous phenanthrene and mercury removal.

PubMed

Tang, Jingchun; Lv, Honghong; Gong, Yanyan; Huang, Yao

2015-11-01

A graphene/biochar composite (G/BC) was synthesized via slow pyrolysis of graphene (G) pretreated wheat straw, and tested for the sorption characteristics and mechanisms of representative aqueous contaminants (phenanthrene and mercury). Structure and morphology analysis showed that G was coated on the surface of biochar (BC) mainly through π-π interactions, resulting in a larger surface area, more functional groups, greater thermal stability, and higher removal efficiency of phenanthrene and mercury compared to BC. Pseudo second-order model adequately simulated sorption kinetics, and sorption isotherms of phenanthrene and mercury were simulated well by dual-mode and BET models, respectively. FTIR and SEM analysis suggested that partitioning and surface sorption were dominant mechanisms for phenanthrene sorption, and that surface complexation between mercury and C-O, CC, -OH, and OC-O functional groups was responsible for mercury removal. The results suggested that the G/BC composite is an efficient, economic, and environmentally friendly multifunctional adsorbent for environmental remediation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Switchgrass biochar affects two aridisols.

PubMed

Ippolito, J A; Novak, J M; Busscher, W J; Ahmedna, M; Rehrah, D; Watts, D W

2012-01-01

The use of biochar has received growing attention because of its ability to improve the physicochemical properties of highly weathered Ultisols and Oxisols, yet very little research has focused on its effects in Aridisols. We investigated the effect of low or high temperature (250 or 500°C) pyrolyzed switchgrass () biochar on two Aridisols. In a pot study, biochar was added at 2% w/w to a Declo loam (Xeric Haplocalcids) or to a Warden very fine sandy loam (Xeric Haplocambids) and incubated at 15% moisture content (by weight) for 127 d; a control (no biochar) was also included. Soils were leached with 1.2 to 1.3 pore volumes of deionized HO on Days 34, 62, 92, and 127, and cumulative leachate Ca, K, Mg, Na, P, Cu, Fe, Mn, Ni, Zn, NO-N, NO-N, and NH-N concentrations were quantified. On termination of the incubation, soils were destructively sampled for extractable Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Zn, NO-N, and NH-N, total C, inorganic C, organic C, and pH. Compared with 250°C, the 500°C pyrolysis temperature resulted in greater biochar surface area, elevated pH, higher ash content, and minimal total surface charge. For both soils, leachate Ca and Mg decreased with the 250°C switchgrass biochar, likely due to binding by biochar's functional group sites. Both biochars caused an increase in leachate K, whereas the 500°C biochar increased leachate P. Both biochars reduced leachate NO-N concentrations compared with the control; however, the 250°C biochar reduced NO-N concentrations to the greatest extent. Easily degradable C, associated with the 250°C biochar's structural make-up, likely stimulated microbial growth, which caused NO-N immobilization. Soil-extractable K, P, and NO-N followed a pattern similar to the leachate observations. Total soil C content increases were linked to an increase in organic C from the biochars. Cumulative results suggest that the use of switchgrass biochar prepared at 250°C could improve environmental quality in calcareous soil systems by reducing nutrient leaching potential. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Site energy distribution analysis and influence of Fe3O4 nanoparticles on sulfamethoxazole sorption in aqueous solution by magnetic pine sawdust biochar.

PubMed

Reguyal, Febelyn; Sarmah, Ajit K

2018-02-01

Magnetisation of carbonaceous adsorbents using iron oxides has been found to be one of the potential solutions for easy recovery of adsorbent after use. We evaluated the effects of Fe 3 O 4 nanoparticle addition on the physico-chemical properties of biochar and its sorption properties. Five adsorbents with varying amount of Fe 3 O 4 per mass of adsorbent (0%, 25%, 50%, 75% and 100%) were used to adsorb sulfamethoxazole (SMX), an emerging micropollutant. Five isotherm models were used to evaluate the sorption behaviour of SMX onto the adsorbents where Redlich-Peterson model was found to best describe the data. Based on this model, the approximate site energy distribution for each adsorbent was determined. Surface area and sorption capacity had strong negative linear relationship with the amount of Fe 3 O 4 per mass of adsorbent while the pore volume and saturation magnetisation of the adsorbent increased with increasing percentage of Fe 3 O 4 . The results of the approximate site energy distribution analysis showed that the addition of Fe 3 O 4 on biochar reduced the area under the frequency distribution curve of sorption site energies leading to the lowering of the sorption sites available for SMX. This could be attributed to the blockage of the hydrophobic surface of biochar reducing the hydrophobic interaction between SMX and biochar. Copyright © 2017 Elsevier Ltd. All rights reserved.

Characterization of biochar prepared from biogas digestate.

PubMed

Hung, Chao-Yi; Tsai, Wen-Tien; Chen, Jie-Wei; Lin, Yu-Quan; Chang, Yuan-Ming

2017-08-01

In the study, the biogas digestate was evaluated as a potential feedstock for preparing biochars at a broad temperature range of 300-900°C. The physico-chemical and pore properties of the resulting biochars (denoted as SDBC, solid digestate biochar), including calorific value (higher heating value), surface area/pore volume/pore size distribution, true density, scanning electron microscopy - energy dispersive X-ray spectroscopy (SEM-EDS) and X-ray powder diffraction (XRD), were studied. It was found that the higher heating values of the SDBC products were on a decreasing trend as pyrolysis temperature increased, but they indicated an increase in true density. The results are probably associated with the active pyrolysis of the lignocellulosic fragments and the calcination (or shrinkage) processes, thus resulting in the increased contents of aromatic carbon clusters and main mineral constituents remained. Based on the pore properties, pyrolysis temperature at around 800°C seemed to be the optimal condition for producing SDBC, where its Brunauer-Emmet-Teller (BET) surface area (>100m 2 /g) largely increased as compared to that of the digestate feedstock (<1m 2 /g). Furthermore, the main compositions of mineral ash in the resulting biochar could exist as phosphates, carbonates, or oxides of calcium and other alkali/alkaline earth elements. According to the data on EDS and XRD, more pores could be significantly generated under severe pyrolysis (>700°C) due to the high aromaticity via the thermal decomposition of lignocelluloses and the volatilization of inorganic minerals. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of Biochar amendments on soil chemistry

NASA Astrophysics Data System (ADS)

Mukherjee, A.; Zimmerman, A. R.

2009-12-01

Humans have been transforming soil composition, both accidentally and purposefully, for centuries. For example, terra preta soils found in Amazonia that are greatly enriched in organic carbon and phosphorus and have enhanced fertility relative to the surrounding depleted oxisols, seem to have been deliberately created by native pre-Colombian Indians through the addition of combusted biomass, or biochar. Biochar amendment has gained attention recently as a way to enhance soil carbon sequestration while increasing soil fertility. It may also have adsorptive properties that are useful for pollution control. Our research examines the chemical and morphological properties of biochar with the goals of understanding the origin of terra preta, as well as how biochar can best be put to use as a soil amendment. Biochar was produced from a range of parent biomass types (hardwoods, softwoods and grasses) and under a range of combustion conditions (250 to 650 oC, under air and N2). Surface areas, determined by gas sorptometry, ranged from 3 to 394 m2g-1 (for N2) and from 129 to 345 m2g-1 (for CO2) and were found to generally increase with increasing pyrolysis temperature. The pH of the biochars ranged from 1.8 to 4.5, from 6.2 to 8.7, and from 6.2 to 9.2 for the 250, 400, and 650 oC biochars, respectively, and did not vary consistently with parent biomass types. Cation exchange capacity (CEC), determined using K+ exchange, ranged between 5 to 60 cmolc kg-1, higher than most soils, and generally increased with charring temperature. Anion exchange capacity (AEC) was low or undetectable. Lastly, the isoelectric point of the chars, determined using a zeta potential analyzer, ranged from a pH of 1.3 to 1.5, indicating that the biochar surfaces will be predominantly negatively charged in soil solutions. These data are complimentary and show that, when added to soil, biochar, particularly those produced at higher temperatures, would function as a cation exchanger system. The acid functional groups present on biochar surfaces would attract and adsorb cationic nutrients such as calcium, magnesium, iron, and ammonium, which would likely increase soil fertility. However, absorption of organic matter and water into the pore system of the chars may also play a role in enhancing the fertility of biochar-amended soils. Functional group chemistry determined by mid-range IR spectroscopy and scanning electron microscope images of biochars will also be presented.

On alleviation of atrazine and imidacloprid contamination from single component aqueous systems using rice straw biochars: An Optimization Study

NASA Astrophysics Data System (ADS)

Mandal, Abhishek; Singh, Neera

2017-04-01

Contamination of surface and ground water by pesticides from agricultural runoff and industrial discharge is one of the main causes of aqueous contaminations world over. Adsorption of pesticide on adsorbents is considered as the most feasible approach of decontamination. Biochar, agricultural waste derived highly aromatic substance produced after pyrolysis and carbonification of biomass have exhibited good adsorption capacity for pesticides and can be used to develop on-site bio-purification systems for organic contaminant removal from polluted waters. Normal (RSBC) and phosphoric acid treated (T-RSBC) rice straw biochars were characterized for their physico-chemical properties. The yield parameters of biochar suggested higher biomass-biochar conversion ratio for the rice biochar. T-RSBC (pH=6.93) was neutral whereas RSBC was alkaline in nature. The cation exchange capacity (CEC) of the biochars were quite high. Elemental analysis (C, H, N, O) of biochars suggested a higher total carbon content (47.7-49.5%) and degree of aromaticity (H/C 0.62-0.63) indicating increased stability of biochars than the parent feedstocks. Polarity increased when T-RSBC (O/C 0.416) was synthesized from RSBC (O/C 0.410). The surface area, pore volume and micropore volume of the biochars, calculated using BET N2 adsorption method, suggested that RSBC was the most porous biochar (220.2 m2 g-1) amongst the two studied. IR, SEM and XRD analysis of biochars suggested the presence of inorganic minerals, carbonates, aromatic moieties and carboxylic groups. Zeta potential measurement indicated that biochars' surfaces carried negative charges while Boehm titration results suggested abundant presence of surface acidic functional groups on both the biochars. Fairly good atrazine and imidacloprid removal were shown by RSBC (KFads,Atrz = 1363; KFads,Imida =1706) and T-RSBC (KFads,Atrz=2716; KFads,Imida= 3140). Results obtained by fitting the atrazine and imidacloprid adsorption data to the Freundlich adsorption isotherm were modelled to develop single or multistage batch sorption systems. Amounts (kg 1000L-1) of RSBC and T-RSBC required for 95% of atrazine removal from 10 g L-1 solution in single-, two- and three-stage systems were 8.84, 2.44, 1.61 kg and 4.47, 1.42, 0.98 kg, respectively. Corresponding amounts for imidacloprid removal were 3.97, 1.22, 0.84 kg and 3.98, 1.38, 0.96 kg, respectively. Thus, two-stage system suggested 65-72% reduction in amount of adsorbent required over single stage system while three-stage system suggested 30-34% adsorbent saving over two-stage system. Single and two stage adsorber plant model findings were validated using the jar test appratus simulation of a low-cost water treatment plant. Rice straw based biochars were highly effective in removing pesticides from water and have great potential to replace costly commercial activated carbons for on-site remediation of contaminated water. Furthermore, the jar test validation results suggested the amounts, calculated using modelling studies, to be fairly accurate and thereby optimizing the performance of the water treatment plant. Key words: Biochar, Freundlich isotherm, Low-cost water treatment plant

Adsorption of selected endocrine disrupting compounds and pharmaceuticals on activated biochars.

PubMed

Jung, Chanil; Park, Junyeong; Lim, Kwang Hun; Park, Sunkyu; Heo, Jiyong; Her, Namguk; Oh, Jeill; Yun, Soyoung; Yoon, Yeomin

2013-12-15

Chemically activated biochar produced under oxygenated (O-biochar) and oxygen-free (N-biochar) conditions were characterized and the adsorption of endocrine disrupting compounds (EDCs): bisphenol A (BPA), atrazine (ATR), 17 α-ethinylestradiol (EE2), and pharmaceutical active compounds (PhACs); sulfamethoxazole (SMX), carbamazepine (CBM), diclofenac (DCF), ibuprofen (IBP) on both biochars and commercialized powdered activated carbon (PAC) were investigated. Characteristic analysis of adsorbents by solid-state nuclear magnetic resonance (NMR) was conducted to determine better understanding about the EDCs/PhACs adsorption. N-biochar consisted of higher polarity moieties with more alkyl (0-45 ppm), methoxyl (45-63 ppm), O-alkyl (63-108 ppm), and carboxyl carbon (165-187 ppm) content than other adsorbents, while aromaticity of O-biochar was higher than that of N-biochar. O-biochar was composed mostly of aromatic moieties, with low H/C and O/C ratios compared to the highly polarized N-biochar that contained diverse polar functional groups. The higher surface area and pore volume of N-biochar resulted in higher adsorption capacity toward EDCs/PhACs along with atomic-level molecular structural property than O-biochar and PAC. N-biochar had a highest adsorption capacity of all chemicals, suggesting that N-biochar derived from loblolly pine chip is a promising sorbent for agricultural and environmental applications. The adsorption of pH-sensitive dissociable SMX, DCF, IBP, and BPA varied and the order of adsorption capacity was correlated with the hydrophobicity (Kow) of adsorbates throughout the all adsorbents, whereas adsorption of non-ionizable CBM, ATR, and EE2 in varied pH allowed adsorbents to interact with hydrophobic property of adsorbates steadily throughout the study. Copyright © 2013 Elsevier B.V. All rights reserved.

Metal Interactions at the Biochar-Water Interface: Energetics and Structure-Sorption Relationships Elucidated by Flow Adsorption Microcalorimetry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harvey, Omar R.; Herbert, Bruce; Rhue, Roy D.

2011-06-01

Interest in biochars and their role in the biogeochemical cycling of metals have increased in recent years. However, a systematic understanding of the mechanisms involved in biochar-metal interactions and conditions under which a given mechanism is predominant is still needed. We used flow adsorption micro-calorimetry to study structure-sorption relationships between twelve plant-derived biochars and two metals of different ionization potential (Ip). Biochar structure influenced the amount of K+ (Ip = 419 kJ mol-1) or Cd(II) (Ip = 868 kJ mol-17 ) sorption but had no effect on the mechanism of sorption. Irrespective of the biochar, K+ sorption was exothermic, surface-controlledmore » and occurred via an ion-exchange mechanism on negatively- charged sites with molar heats of adsorption (_Hads) of -4 kJ mol-1 on wood versus -8 kJ mol-1 on grass biochars. In contrast, Cd(II) sorption was endothermic and favored surface complexation on uncharged biochar surfaces with _Hads of around +17 kJ mol-1. Cadmium sorption transitioned from surface- to diffusion-controlled on biochars formed at ≥ 350 oC and _Hads for Cd(II) sorption was the same on grass and wood biochars. We concluded that, in general, metals with lower Ip favor electrostatic interactions with biochars, while metals of higher Ip favor more covalent-like interactions.« less

Influence of Biochar on Deposition and Release of Clay Colloids in Saturated Porous Media.

PubMed

Haque, Muhammad Emdadul; Shen, Chongyang; Li, Tiantian; Chu, Haoxue; Wang, Hong; Li, Zhen; Huang, Yuanfang

2017-11-01

Although the potential application of biochar in soil remediation has been recognized, the effect of biochar on the transport of clay colloids, and accordingly the fate of colloid-associated contaminants, is unclear to date. This study conducted saturated column experiments to systematically examine transport of clay colloids in biochar-amended sand porous media in different electrolytes at different ionic strengths. The obtained breakthrough curves were simulated by the convection-diffusion equation, which included a first-order deposition and release terms. The deposition mechanisms were interpreted by calculating Derjaguin-Landau-Verwey-Overbeek interaction energies. A linear relationship between the simulated deposition rate or the attachment efficiency and the fraction of biochar was observed ( ≥ 0.91), indicating more favorable deposition in biochar than in sand. The interaction energy calculations show that the greater deposition in biochar occurs because the half-tube-like cavities on the biochar surfaces favor deposition in secondary minima and the nanoscale physical and chemical heterogeneities on the biochar surfaces increase deposition in primary minima. The deposited clay colloids in NaCl can be released by reduction of ionic strength, whereas the presence of a bivalent cation (Ca) results in irreversible deposition due to the formation of cation bridging between the colloids and biochar surfaces. The deposition and release of clay colloids on or from biochar surfaces not only change their mobilizations in the soil but also influence the efficiency of the biochar for removal of pollutants. Therefore, the influence of biochar on clay colloid transport must be considered before application of the biochar in soil remediation. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Characteristics of maize biochar with different pyrolysis temperatures and its effects on organic carbon, nitrogen and enzymatic activities after addition to fluvo-aquic soil.

PubMed

Wang, Xiubin; Zhou, Wei; Liang, Guoqing; Song, Dali; Zhang, Xiaoya

2015-12-15

In this study, the characteristics of maize biochar produced at different pyrolysis temperatures (300, 450 and 600°C) and its effects on organic carbon, nitrogen and enzymatic activities after addition to fluvo-aquic soil were investigated. As pyrolysis temperature increased, ash content, pH, electrical conductivity, surface area, pore volume and aromatic carbon content of biochar increased while yield, ratios of oxygen:carbon and hydrogen: carbon and alkyl carbon content decreased. During incubation, SOC, total N, and ammonium-N contents increased in all biochar-amended treatments compared with the urea treatment; however, soil nitrate-N content first increased and then decreased with increasing pyrolysis temperature of the applied biochar. Extracellular enzyme activities associated with carbon transformation first increased and then decreased with biochars pyrolyzed at 450 and 600°C. Protease activity markedly increased with increased pyrolysis temperatures, whereas pyrolysis temperature had limited effect on soil urease activity. The results indicated that the responses of extracellular enzymes to biochar were dependent on the pyrolysis temperature, the enzyme itself and incubation time as well. Copyright © 2015. Published by Elsevier B.V.

Preparation of biochar from Enteromorpha prolifera and its use for the removal of polycyclic aromatic hydrocarbons (PAHs) from aqueous solution.

PubMed

Qiao, Kaili; Tian, Weijun; Bai, Jie; Dong, Jie; Zhao, Jing; Gong, Xiaoxi; Liu, Shuhui

2018-03-01

EP-biochar was produced from Enteromorpha prolifera (EP) at temperatures of 200-600°C under limited-oxygen conditions and then activated using HCl and HF. To optimize the sorption of pyrene (PYR) and benzo[a]pyrene (BaP), the effect of the pyrolysis temperature was studied, and the results showed that EP-biochar produced at 500°C gave the highest removal efficiency. The physiochemical properties of EP-biochar pyrolyzed at 500°C were characterized. The examination indicated that the surface area of EP-biochar was 205.32m 2 /g. The effect of the EP-biochar dosage and initial solution pH on the adsorption were studied in batch adsorption experiments. Kinetic studies indicated that the adsorption processes of PYR and BaP agreed well with a pseudo second-order kinetic model. The sorption equilibrium data were well described by the Langmuir model. Desorption experiments were conducted to test the strength of binding interactions of EP-biochar. The results showed that PYR and BaP were difficult to dissolve in water after adsorption. Regeneration experiments demonstrated that the biochars regenerated at 200°C retained approximately 48% and 40% of their initial PYR and BaP uptake. Copyright © 2017 Elsevier Inc. All rights reserved.

Efficiency of biochar produced from malt spent rootlets to remove mercury and dyes

NASA Astrophysics Data System (ADS)

Kamenidou, Charoula; Manariotis, Ioannis; Karapanagioti, Hrissi

2017-04-01

Considerable research effort has been focused on the production of biochar from carbon-rich biomass under oxygen-limited conditions as a mitigation measure for global warming once it is used as a soil amendment. Furthermore, the use of biochar as an added value product, such as sorbent or catalyst, is desirable and could be more profitable. Biochar is obtained from the incomplete combustion of carbon-rich biomass under oxygen-limited conditions. Various organic-rich wastes including wood chips, animal manure, and crop residues have been used for biochar production. The present study presents the findings of an experimental work, which investigated the use of biochar produced from malt spent rootlets (MSR), which is a beer production by-product, to remove Hg(II) and methylene blue (MB) from aqueous solutions. MSR was pyrolyzed at temperatures of 300, 400, 500, 600, 750, 850, and 900oC, under limited oxygen conditions. The increase of temperature resulted in significantly increased BET surface areas. The mercury sorption capacity was affected by pyrolysis temperature, and was increased by increasing the pyrolysis temperature. The maximum sorption capacity was 100-110 mg Hg(II)/g biochar at a temperature range of 750-850oC. The MB sorption capacity of biochar was also affected by pyrolysis temperature.

The Interfacial Behavior between Biochar and Soil Minerals and Its Effect on Biochar Stability.

PubMed

Yang, Fan; Zhao, Ling; Gao, Bin; Xu, Xiaoyun; Cao, Xinde

2016-03-01

In this study, FeCl3, AlCl3, CaCl2, and kaolinite were selected as model soil minerals and incubated with walnut shell derived biochar for 3 months and the incubated biochar was then separated for the investigation of biochar-mineral interfacial behavior using XRD and SEM-EDS. The XPS, TGA, and H2O2 oxidation were applied to evaluate effects of the interaction on the stability of biochar. Fe8O8(OH)8Cl1.35 and AlCl3·6H2O were newly formed on the biochar surface or inside of the biochar pores. At the biochar-mineral interface, organometallic complexes such as Fe-O-C were generated. All the 4 minerals enhanced the oxidation resistance of biochar surface by decreasing the relative contents of C-O, C═O, and COOH from 36.3% to 16.6-26.5%. Oxidation resistance of entire biochar particles was greatly increased with C losses in H2O2 oxidation decreasing by 13.4-79.6%, and the C recalcitrance index (R50,bicohar) in TGA analysis increasing from 44.6% to 45.9-49.6%. Enhanced oxidation resistance of biochar surface was likely due to the physical isolation from newly formed minerals, while organometallic complex formation was probably responsible for the increase in oxidation resistance of entire biochar particles. Results indicated that mineral-rich soils seemed to be a beneficial environment for biochar since soil minerals could increase biochar stability, which displays an important environmental significance of biochar for long-term carbon sequestration.

Aging impacts of low molecular weight organic acids (LMWOAs) on furfural production residue-derived biochars: Porosity, functional properties, and inorganic minerals.

PubMed

Liu, Guocheng; Chen, Lei; Jiang, Zhixiang; Zheng, Hao; Dai, Yanhui; Luo, Xianxiang; Wang, Zhenyu

2017-12-31

The aging of biochar by low molecular weight organic acids (LMWOAs), which are typical root-derived exudates, is not well understood. Three LMWOAs (ethanoic, malic, and citric acids) were employed to investigate their aging impacts on the biochars from furfural production residues at 300-600°C (BC300-600). The LMWOAs created abundant macropores in BC300, whereas they significantly increased the mesoporosity and surface area of BC600 by 13.5-27.0% and 44.6-61.5%, respectively. After LMWOA aging, the content of C and H of the biochars increased from 51.3-60.2% and 1.87-3.45% to 56.8-69.9% and 2.06-4.45%, respectively, but the O content decreased from 13.8-24.8% to 7.82-19.4% (except BC300). For carbon fraction in the biochars, the LMWOAs barely altered the bulk and surface functional properties during short-term aging. The LMWOAs facilitated the dissolution of minerals (e.g., K 2 Mg(PO 3 ) 4 , AlPO 4 , and Pb 2 P 2 O 7 ) and correspondingly promoted the release of not only plant nutrients (K + , Ca 2+ , Mg 2+ , Fe 3+ , PO 4 3- , and SO 4 2- ) but also toxic metals (Al 3+ and Pb 2+ ). This research provided systematic insights on the responses of biochar properties to LMWOAs and presented direct evidence for acid activation of inorganic minerals in the biochars by LMWOAs, which could enhance the understanding of environmental behaviors of biochars in rhizosphere soils. Copyright © 2017 Elsevier B.V. All rights reserved.

Evaluation of the performance of biochars as an adsorbent for polycyclic aromatic hydrocarbons

NASA Astrophysics Data System (ADS)

Jung, J.; Kang, S.; Ok, Y.; Choi, Y.

2016-12-01

Biochars, byproducts generated by pyrolysis of biomass, are known to have several advantages as a soil amendment such as carbon sequestration effect, enhancement of soil microbial activity, and nutrient supply. Because of their high surface area and affinity to organic pollutants, biochars are also being evaluated as an adsorbent for hydrophobic organic pollutants such as polycyclic aromatic hydrocarbons (PAHs) in soils, stormwater, and wastewater. Depending on their organic precursors and pyrolysis temperatures, biochars have been shown to have various physicochemical properties, which should determine their performance as an adsorbent for hydrophobic organic pollutants. In this study, we obtained biochars derived from soybean stover, wood chip, rice husk, and sewage sludge with pyrolysis temperatures of 700°, 250°, 500°, and 500°, respectively, to investigate their performance for PAH adsorption. Adsorption kinetic and isotherm experiments were conducted using naphthalene and phenanthrene as model compounds. Soybean stover biochar reached close to equilibrium in 7 days while the others did in 25 days in the kinetic experiments. The first-order sorption rate constants were greater for naphthalene than for phenanthrene for all biochars studied, and they were generally in the order of soybean stover>rice husk>sewage sludge>wood chip biochars for the two contaminants. The removal rates of aqueous PAHs at equilibrium were in the order of soybean stover>rice husk>sewage sludge>wood chip biochars at a concentration range of a few ng/mL. The results suggested that the sorption capability and the rate is generally greater for biochar produced from plant materials than that from sludge, and for biochar produced at higher pyrolysis temperature. Comparing the sorption properties of the biochars and granular activated carbon (GAC), it is shown that biochar produced at optimal conditions can exhibit performance for PAH adsorption similar to GAC.

Biochar amendment reduced methylmercury accumulation in rice plants.

PubMed

Shu, Rui; Wang, Yongjie; Zhong, Huan

2016-08-05

There is growing concern about methylmercury (MeHg) accumulation in rice grains and thus enhanced dietary exposure to MeHg in Asian countries. Here, we explored the possibility of reducing grain MeHg levels by biochar amendment, and the underlying mechanisms. Pot (i.e., rice cultivation in biochar amended soils) and batch experiments (i.e., incubation of amended soils under laboratory conditions) were carried out, to investigate MeHg dynamics (i.e., MeHg production, partitioning and phytoavailability in paddy soils, and MeHg uptake by rice) under biochar amendment (1-4% of soil mass). We demonstrate for the first time that biochar amendment could evidently reduce grain MeHg levels (49-92%). The declines could be attributed to the combined effects of: (1) increased soil MeHg concentrations, probably explained by the release of sulfate from biochar and thus enhanced microbial production of MeHg (e.g., by sulfate-reducing bacteria), (2) MeHg immobilization in soils, facilitated by the large surface areas and high organosulfur content of biochar, and (3) biodilution of MeHg in rice grains, due to the increased grain biomass under biochar amendment (35-79%). These observations together with mechanistic explanations improve understanding of MeHg dynamics in soil-rice systems, and support the possibility of reducing MeHg phytoaccumulation under biochar amendment. Copyright © 2016 Elsevier B.V. All rights reserved.

Influence of pyrolysis temperature on properties and environmental safety of heavy metals in biochars derived from municipal sewage sludge.

PubMed

Jin, Junwei; Li, Yanan; Zhang, Jianyun; Wu, Shengchun; Cao, Yucheng; Liang, Peng; Zhang, Jin; Wong, Ming Hung; Wang, Minyan; Shan, Shengdao; Christie, Peter

2016-12-15

Dried raw sludge was pyrolyzed at temperatures ranging from 400 to 600°C at the increase of 50°C intervals to investigate the influence of pyrolysis temperature on properties and environmental safety of heavy metals in biochar derived from municipal sewage sludge. The sludge biochar yield decreased significantly with increasing pyrolysis temperature but the pH, ash content and specific surface area increased. Conversion of sludge to biochar markedly decreased the H/C and N/C ratios. FT-IR analysis confirmed a dramatic depletion of H and N and a higher degree of aromatic condensation in process of biochar formation at higher temperatures. The total concentrations of Cu, Zn, Pb, Cr, Mn, and Ni increased with conversion of sludge to biochar and increasing pyrolysis temperature. However, using BCR sequential extraction and analysis, it was found that most of the heavy metals existed in the oxizable and residual forms after pyrolysis, especially at 600°C, resulting in a significant reduction in their bioavailability, leading to a very low environmental risk of the biochar. The present study indicates pyrolysis is a promising sludge treatment method for heavy metals immobilization in biochar, and highlights the potential to minimize the harmful effects of biochar by controlling pyrolysis temperature. Copyright © 2016 Elsevier B.V. All rights reserved.

Biochar-based constructed wetlands to treat reverse osmosis rejected concentrates in chronic kidney disease endemic areas in Sri Lanka.

PubMed

Athapattu, B C L; Thalgaspitiya, T W L R; Yasaratne, U L S; Vithanage, Meththika

2017-12-01

The objectives were to investigate the potential remedial measures for reverse osmosis (RO) rejected water through constructed wetlands (CWs) with low-cost materials in the media established in chronic kidney disease of unknown etiology (CKDu) prevalent area in Sri Lanka. A pilot-scale surface and subsurface water CWs were established at the Medawachchiya community-based RO water supply unit. Locally available soil, calicut tile and biochar were used in proportions of 81, 16.5 and 2.5% (w/w), respectively, as filter materials in the subsurface. Vetiver grass and Scirpus grossus were selected for subsurface wetland while water lettuce and water hyacinth were chosen for free water surface CWs. Results showed that the CKDu sensitive parameters; total dissolved solids, hardness, total alkalinity and fluoride were reduced considerably (20-85%) and most met desirable levels of stipulated ambient standards. Biochar seemed to play a major role in removing fluoride from the system which may be due to the existing and adsorbed K + , Ca +2 , Mg +2 , etc. on the biochar surface via chemisorption. The least reduction was observed for alkalinity. This study indicated potential purification of aforesaid ions in water which are considerably present in RO rejection. Therefore, the invented bio-geo constructed wetland can be considered as a sustainable, economical and effective option for reducing high concentrations of CKDu sensitive parameters in RO rejected water before discharging into the inland waters.

Biochar from "Kon Tiki" flame curtain and other kilns: Effects of nutrient enrichment and kiln type on crop yield and soil chemistry

PubMed Central

Pandit, Naba Raj; Mulder, Jan; Hale, Sarah Elisabeth; Schmidt, Hans Peter

2017-01-01

Biochar application to soils has been investigated as a means of improving soil fertility and mitigating climate change through soil carbon sequestration. In the present work, the invasive shrub "Eupatorium adenophorum" was utilized as a sustainable feedstock for making biochar under different pyrolysis conditions in Nepal. Biochar was produced using several different types of kilns; four sub types of flame curtain kilns (deep-cone metal kiln, steel shielded soil pit, conical soil pit and steel small cone), brick-made traditional kiln, traditional earth-mound kiln and top lift up draft (TLUD). The resultant biochars showed consistent pH (9.1 ± 0.3), cation exchange capacities (133 ± 37 cmolc kg-1), organic carbon contents (73.9 ± 6.4%) and surface areas (35 to 215 m2/g) for all kiln types. A pot trial with maize was carried out to investigate the effect on maize biomass production of the biochars made with various kilns, applied at 1% and 4% dosages. Biochars were either pretreated with hot or cold mineral nutrient enrichment (mixing with a nutrient solution before or after cooling down, respectively), or added separately from the same nutrient dosages to the soil. Significantly higher CEC (P< 0.05), lower Al/Ca ratios (P< 0.05), and high OC% (P<0.001) were observed for both dosages of biochar as compared to non-amended control soils. Importantly, the study showed that biochar made by flame curtain kilns resulted in the same agronomic effect as biochar made by the other kilns (P > 0.05). At a dosage of 1% biochar, the hot nutrient-enriched biochar led to significant increases of 153% in above ground biomass production compared to cold nutrient-enriched biochar and 209% compared to biochar added separately from the nutrients. Liquid nutrient enhancement of biochar thus improved fertilizer effectiveness compared to separate application of biochar and fertilizer. PMID:28448621

Biochar from "Kon Tiki" flame curtain and other kilns: Effects of nutrient enrichment and kiln type on crop yield and soil chemistry.

PubMed

Pandit, Naba Raj; Mulder, Jan; Hale, Sarah Elisabeth; Schmidt, Hans Peter; Cornelissen, Gerard

2017-01-01

Biochar application to soils has been investigated as a means of improving soil fertility and mitigating climate change through soil carbon sequestration. In the present work, the invasive shrub "Eupatorium adenophorum" was utilized as a sustainable feedstock for making biochar under different pyrolysis conditions in Nepal. Biochar was produced using several different types of kilns; four sub types of flame curtain kilns (deep-cone metal kiln, steel shielded soil pit, conical soil pit and steel small cone), brick-made traditional kiln, traditional earth-mound kiln and top lift up draft (TLUD). The resultant biochars showed consistent pH (9.1 ± 0.3), cation exchange capacities (133 ± 37 cmolc kg-1), organic carbon contents (73.9 ± 6.4%) and surface areas (35 to 215 m2/g) for all kiln types. A pot trial with maize was carried out to investigate the effect on maize biomass production of the biochars made with various kilns, applied at 1% and 4% dosages. Biochars were either pretreated with hot or cold mineral nutrient enrichment (mixing with a nutrient solution before or after cooling down, respectively), or added separately from the same nutrient dosages to the soil. Significantly higher CEC (P< 0.05), lower Al/Ca ratios (P< 0.05), and high OC% (P<0.001) were observed for both dosages of biochar as compared to non-amended control soils. Importantly, the study showed that biochar made by flame curtain kilns resulted in the same agronomic effect as biochar made by the other kilns (P > 0.05). At a dosage of 1% biochar, the hot nutrient-enriched biochar led to significant increases of 153% in above ground biomass production compared to cold nutrient-enriched biochar and 209% compared to biochar added separately from the nutrients. Liquid nutrient enhancement of biochar thus improved fertilizer effectiveness compared to separate application of biochar and fertilizer.

Sorption of halogenated phenols and pharmaceuticals to biochar: affecting factors and mechanisms.

PubMed

Oh, Seok-Young; Seo, Yong-Deuk

2016-01-01

The feasibility of using biochar as a sorbent to remove nine halogenated phenols (2,4-dichlorophenol, 2,4-dibromophenol, 2,4-difluorophenol, 2-chlorophenol, 4-chlorophenol, 2-bromophenol, 4-bromophenol, 2-fluorophenol, and 4-fluorophenol) and two pharmaceuticals (triclosan and ibuprofen) from water was examined through a series of batch experiments. Types of biochar, synthesized using various biomasses including fallen leaves, rice straw, corn stalk, used coffee grounds, and biosolids, were evaluated. Compared to granular activated carbon (GAC), most of the biochar samples did not effectively remove halogenated phenols or pharmaceuticals from water. The increase in pH and deprotonation of phenols in biochar systems may be responsible for its ineffectiveness at this task. When pH was maintained at 4 or 7, the sorption capacity of biochar was markedly increased. Considering maximum sorption capacity and properties of sorbents and sorbates, it appears that the sorption capacity of biochar for halogenated phenols is related to the surface area and carbon content of the biochar and the hydrophobicity of halogenated phenols. In the cases of triclosan and ibuprofen, the sorptive capacities of GAC, graphite, and biochars were also significantly affected by pH, according to the point of zero charge (PZC) of sorbents and deprotonation of the pharmaceuticals. Pyrolysis temperature did not affect the sorption capacity of halogenated phenols or pharmaceuticals. Based on the experimental observations, some biochars are good candidates for removal of halogenated phenols, triclosan, and ibuprofen from water and soil.

Generalized Two-Dimensional Perturbation Correlation Infrared Spectroscopy reveals Mechanisms for the Development of Surface Charge and Recalcitrance in Plant-derived Biochars

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harvey, Omar R.; Herbert, Bruce; Kuo, Li-Jung

2012-09-05

Fundamental knowledge of how biochars develop surface-charge and resistance to environmental degradation (or recalcitrance) is crucial to their production for customized applications or, understanding their functions in the environment. Two-dimensional perturbation-based correlation infrared spectroscopy (2D-PCIS) was used to study the biochar formation process in three taxonomically-different plant biomass, under oxygen-limited conditions along a heat-treatment-temperature gradient (HTT; 200-650 oC). Results from 2D-PCIS pointed to the systematic, HTT-induced defragmenting of lignocellulose H-bonding network, and demethylenation/demethylation, oxidation or dehydroxylation/dehydrogenation of lignocellulose fragments as the primary reactions controlling biochar properties along the HTT gradient. The cleavage of OH O-type H-bonds, oxidation of free primarymore » hydroxyls (HTT≤500 oC), and their subsequent dehydrogenation/dehydroxylation (HTT>500 oC) controlled surface charge on the biochars; while the dehydrogenation of methylene groups, which yielded increasingly condensed structures (R-CH2-R →R=CH-R →R=C=R), controlled biochar recalcitrance. Variations in biochar properties across plant biomass type were attributable to taxa-specific transformations. For example, apparent inefficiencies in the cleavage of wood-specific H-bonds, and their subsequent oxidation to carboxyls, lead to lower surface charge in wood biochars (compared to grass biochars). Both non-taxa and taxa-specific transformations highlighted by 2D-PCIS could have significant implications for biochar functioning in fire-impacted or biochar-amended systems.« less

Alteration of biochar characteristics through Post Production Treatments

NASA Astrophysics Data System (ADS)

Schmidt, Hans-Peter; Kammann, Claudia; Glaser, Bruno

2013-04-01

The application of pure, untreated biochar to temperate soils does not lead to substantial increase in soil fertility and plant growth. Moreover, the application of 10 tonnes or more of biochar per hectare is not economically viable on most farms. To be more efficient in improving soil fertility, increasing SOM and ecosystem services, new methods of using biochar in farm settings need to be developed. To improve the effect of biochar on plant growth, biochar can be enhanced by (1) adding nutrients, (2) inoculating it with beneficial microorganisms, (3) improving its surface reactivity and thus its sorption dynamic, (4) increasing its porous volume, and/or (5) fostering the creation of biochar-mineral-organic complexes. These supplementary biochar enhancements can be achieved through different methods of feedstock blending and biochar post-production treatment which can be classified according to the resulting surface alteration of biochar: 1. Addition of nutrients, MOs, minerals in liquid solution which get soaked into the biochar pores without or with only slight surface alteration, resulting in enriched biochar. 2. Physico-chemical activation (treatment with acids, vapours, toasting with minerals …) resulting in alteration of the surface, pore volume and functional groups. 3. Bio-chemical activation through the interaction of biochar with organic compounds, minerals, nutrients and microorganisms in a biological very active environment, resulting in the complexation of biochar, minerals and organic compounds. Whereas physico-chemical activation is a highly technical process and has to be done by professional biochar producers, bio-chemical activation and enrichment can be done very efficiently by the farmer himself. On-farm enrichment and activation of biochar help to close the organic nutrient cycles of the farm, improving agronomic system efficiency and thus becoming economically viable. Adding biochar to highly labile organic matter like manure, sludge or compost improves decomposition and complexation, and helps to stabilize their nutrients and carbon. The combination of biochar and lacto-acid-bacteria in silage, feed, bedding and liquid manure treatment decreases methane and ammonia emissions, increases the feed-energy balance, and boosts animal health. On every step of this cascading use of biochar in animal husbandry, the biochar becomes more oxidized, more activated and more enriched with nutrients. When finally applied to the soil, biochar acts as carrier for nutrients and thus works to improve soil fertility. Much more research is needed in the field of biochar post-treatment and into each of the different possible farm uses. Nevertheless, sufficient serious research has already been done and published, enabling us to judge the importance of post-treating biochar to improve its agronomic performance and value.

Production of 5-hydroxymethylfurfural from starch-rich food waste catalyzed by sulfonated biochar.

PubMed

Cao, Leichang; Yu, Iris K M; Chen, Season S; Tsang, Daniel C W; Wang, Lei; Xiong, Xinni; Zhang, Shicheng; Ok, Yong Sik; Kwon, Eilhann E; Song, Hocheol; Poon, Chi Sun

2018-03-01

Sulfonated biochar derived from forestry wood waste was employed for the catalytic conversion of starch-rich food waste (e.g., bread) into 5-hydroxymethylfurfural (HMF). Chemical and physical properties of catalyst were characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) surface area, and elemental analysis. The conversion of HMF was investigated via controlling the reaction parameters such as catalyst loading, temperature, and reaction time. Under the optimum reaction conditions the HMF yield of 30.4 Cmol% (i.e., 22 wt% of bread waste) was achieved in the mixture of dimethylsulfoxide (DMSO)/deionized-water (DIW) at 180 °C in 20 min. The effectiveness of sulfonated biochar catalyst was positively correlated to the density of strong/weak Brønsted acidity (SO 3 H, COOH, and OH groups) and inversely correlated to humins content on the surface. With regeneration process, sulfonated biochar catalyst displayed excellent recyclability for comparable HMF yield from bread waste over five cycles. Copyright © 2017 Elsevier Ltd. All rights reserved.

Role of biochar as an additive in organic waste composting.

PubMed

Sanchez-Monedero, M A; Cayuela, M L; Roig, A; Jindo, K; Mondini, C; Bolan, N

2018-01-01

The use of biochar in organic waste composting has attracted interest in the last decade due to the environmental and agronomical benefits obtained during the process. Biochar presents favourable physicochemical properties, such as large porosity, surface area and high cation exchange capacity, enabling interaction with major nutrient cycles and favouring microbial growth in the composting pile. The enhanced environmental conditions can promote a change in the microbial communities that can affect important microbially mediated biogeochemical cycles: organic matter degradation and humification, nitrification, denitrification and methanogenesis. The main benefits of the use of biochar in composting are reviewed in this article, with special attention to those related to the process performance, compost microbiology, organic matter degradation and humification, reduction of N losses and greenhouse gas emissions and fate of heavy metals. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Potential application of gasification to recycle food waste and rehabilitate acidic soil from secondary forests on degraded land in Southeast Asia.

PubMed

Yang, Zhanyu; Koh, Shun Kai; Ng, Wei Cheng; Lim, Reuben C J; Tan, Hugh T W; Tong, Yen Wah; Dai, Yanjun; Chong, Clive; Wang, Chi-Hwa

2016-05-01

Gasification is recognized as a green technology as it can harness energy from biomass in the form of syngas without causing severe environmental impacts, yet producing valuable solid residues that can be utilized in other applications. In this study, the feasibility of co-gasification of woody biomass and food waste in different proportions was investigated using a fixed-bed downdraft gasifier. Subsequently, the capability of biochar derived from gasification of woody biomass in the rehabilitation of soil from tropical secondary forests on degraded land (adinandra belukar) was also explored through a water spinach cultivation study using soil-biochar mixtures of different ratios. Gasification of a 60:40 wood waste-food waste mixture (w/w) produced syngas with the highest lower heating value (LHV) 5.29 MJ/m(3)-approximately 0.4-4.0% higher than gasification of 70:30 or 80:20 mixtures, or pure wood waste. Meanwhile, water spinach cultivated in a 2:1 soil-biochar mixture exhibited the best growth performance in terms of height (a 4-fold increment), weight (a 10-fold increment) and leaf surface area (a 5-fold increment) after 8 weeks of cultivation, owing to the high porosity, surface area, nutrient content and alkalinity of biochar. It is concluded that gasification may be an alternative technology to food waste disposal through co-gasification with woody biomass, and that gasification derived biochar is suitable for use as an amendment for the nutrient-poor, acidic soil of adinandra belukar. Copyright © 2016 Elsevier Ltd. All rights reserved.

Understanding mechanisms to predict and optimize biochar for agrochemical sorption

NASA Astrophysics Data System (ADS)

Hall, Kathleen; Gámiz, Beatriz; Cox, Lucia; Spokas, Kurt; Koskinen, William

2017-04-01

The ability of biochars to bind various organic compounds has been widely studied due to the potential effects on pesticide fate in soil and interest in the adoption of biochar as a "low-cost" filter material. However, the sorptive behaviors of biochars are extremely variable and much of the reported data is limited to specific biochar-chemical interactions. The lack of knowledge regarding biochar sorption mechanisms limits our current ability to predict and optimize biochar's use. This work unveils mechanistic drivers of organic pesticide sorption on biochars through targeted alteration of biochar surface chemistry. Changes in the quantity and type of functional groups on biochars and other black carbon materials were achieved through treatments with H2O2, and CO2, and characterized using Fourier transform infrared spectroscopy and scanning electron microscope (SEM/EDX). The sorption capacities of these treated biochars were subsequently measured to evaluate the effects of different surface moieties on the binding of target herbicides cyhalofop acid ((R)-2-[4-(4-cyano-2-fluorophenoxy)phenoxy]propionic acid) and clomazone (2-[(2-chlorophenyl)methyl]-4,4-dimethyl-1,2-oxazolidin-3-one). Sorption of both herbicides on the studied biochars increased following H2O2 activation; however, the influence of the H2O2 activation on sorption was more pronounced for cyhalofop acid (pKa = 3.9) than clomazone, which is non-ionizable. Increased cyhalofop acid sorption on H2O2 treated biochars can be attributed to the increase in oxygen containing functional groups as well as the decrease in biochar pH. In contrast, CO2 activation reduced the sorption of cyhalofop acid compared to untreated biochar. FTIR data suggest the reduced sorption on CO2 -treated biochar was due to the removal of surface carboxyl groups, further supporting the role of specific functionality in the sorption of ionizable herbicides. Results from this work offer insight into the mechanisms of sorption and provide the basis to simultaneously evaluate the overall effectiveness of surface activation treatments. In addition, we are currently examining the influence of specific biochar alterations via activation on nitrate sorption and uptake; forthcoming results will also be presented.

Effect of biochars produced from solid organic municipal waste on soil quality parameters.

PubMed

Randolph, P; Bansode, R R; Hassan, O A; Rehrah, Dj; Ravella, R; Reddy, M R; Watts, D W; Novak, J M; Ahmedna, M

2017-05-01

New value-added uses for solid municipal waste are needed for environmental and economic sustainability. Fortunately, value-added biochars can be produced from mixed solid waste, thereby addressing solid waste management issues, and enabling long-term carbon sequestration. We hypothesize that soil deficiencies can be remedied by the application of municipal waste-based biochars. Select municipal organic wastes (newspaper, cardboard, woodchips and landscaping residues) individually or in a 25% blend of all four waste streams were used as feedstocks of biochars. Three sets of pyrolysis temperatures (350, 500, and 750 °C) and 3 sets of pyrolysis residence time (2, 4 and 6 h) were used for biochar preparation. The biochar yield was in the range of 21-62% across all feedstocks and pyrolysis conditions. We observed variations in key biochar properties such as pH, electrical conductivity, bulk density and surface area depending on the feedstocks and production conditions. Biochar increased soil pH and improved its electrical conductivity, aggregate stability, water retention and micronutrient contents. Similarly, leachate from the soil amended with biochar showed increased pH and electrical conductivity. Some elements such as Ca and Mg decreased while NO 3 -N increased in the leachates of soils incubated with biochars. Overall, solid waste-based biochar produced significant improvements to soil fertility parameters indicating that solid municipal wastes hold promising potential as feedstocks for manufacturing value-added biochars with varied physicochemical characteristics, allowing them to not only serve the needs for solid waste management and greenhouse gas mitigation, but also as a resource for improving the quality of depleted soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of biochar addition on toxic element concentrations in plants: A meta-analysis.

PubMed

Peng, Xin; Deng, Yinger; Peng, Yan; Yue, Kai

2018-03-01

Consuming food contaminated by toxic elements (TEs) could pose a substantial risk to human health. Recently, biochar has been extensively studied as an effective soil ameliorant in situ because of its ability to suppress the phytoavailability of TEs. However, despite the research interest, the effects of biochar applications to soil on different TE concentrations in different plant parts remain unclear. Here, we synthesize 1813 individual observations data collected from 97 articles to evaluate the effects of biochar addition on TE concentrations in plant parts. We found that (1) the experiment type, biochar feedstock and pyrolysis temperature all significantly decreased the TE concentration in plant parts; (2) the responses of Cd and Pb concentrations in edible and indirectly edible plant parts were significantly more sensitive to the effect of biochar than the Zn, Ni, Mn, Cr, Co and Cu concentrations; and (3) the biochar dosage and surface area, significantly influenced certain TE concentrations in plant tissues as determined via correlation analysis. Moreover, the only exception in this study was found for metalloid element (i.e., As) concentrations in plants, which were not significantly influenced by biochar addition. Overall, the effects of biochar on TE concentrations in plant tissues were negative, at least on average, and the central trends suggest that biochar has a considerable ability to mitigate the transfer of TEs to food, thereby reducing the associated health risks. Our results provide an initial quantitative determination of the effects of biochar addition on multifarious TEs in different plant parts as well as an assessment of the ability of biochar to reduce TE concentrations in plants. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of biochars on hydraulic properties of clayey soil

NASA Astrophysics Data System (ADS)

Zhen, Jingbo; Palladino, Mario; Lazarovitch, Naftali; Bonanomi, Giuliano; Battista Chirico, Giovanni

2017-04-01

Biochar has gained popularity as an amendment to improve soil hydraulic properties. Since biochar properties depend on feedstocks and pyrolysis temperatures used for its production, proper selection of biochar type as soil amendment is of great importance for soil hydraulic properties improvement. This study investigated the effects of eight types of biochar on physical and hydraulic properties of clayey soil. Biochars were derived from four different feedstocks (Alfalfa hay, municipal organic waste, corn residues and wood chip) pyrolyzed at two different temperatures (300 and 550 °C). Clayey soil samples were taken from Leone farm (40° 26' 15.31" N, 14° 59' 45.54" E), Italy, and were oven-dried at 105 °C to determine dry bulk density. Biochars were mixed with the clayey soil at 5% by mass. Bulk densities of the mixtures were also determined. Saturated hydraulic conductivities (Ks) of the original clayey soil and corresponding mixtures were measured by means of falling-head method. Soil water retention measurements were conducted for clayey soil and mixtures using suction table apparatus and Richards' plate with the pressure head (h) up to 12000 cm. van Genuchten retention function was selected to evaluate the retention characteristics of clayey soil and mixtures. Available water content (AWC) was calculated by field capacity (h = - 500 cm) minus wilting pointing (h = -12000 cm). The results showed that biochar addition decreased the bulk density of clayey soil. The Ks of clayey soil increased due to the incorporation of biochars except for waste and corn biochars pyrolyzed at 550 °C. AWC of soils mixed with corn biochar pyrolyzed at 300 °C and wood biochar pyrolyzed at 550 °C, increased by 31% and 7%, respectively. Further analysis will be conducted in combination of biochar properties such as specific surface area and total pore volume. Better understanding of biochar impact on clayey soil will be helpful in biochar selection for soil amendment and improving water use efficiency in agriculture.

Release of Nitrogen and Phosphorus from Poultry Litter Amended with Acidified Biochar

PubMed Central

Doydora, Sarah A.; Cabrera, Miguel L.; Das, Keshav C.; Gaskin, Julia W.; Sonon, Leticia S.; Miller, William P.

2011-01-01

Application of poultry litter (PL) to soil may lead to nitrogen (N) losses through ammonia (NH3) volatilization and to potential contamination of surface runoff with PL-derived phosphorus (P). Amending litter with acidified biochar may minimize these problems by decreasing litter pH and by retaining litter-derived P, respectively. This study evaluated the effect of acidified biochars from pine chips (PC) and peanut hulls (PH) on NH3 losses and inorganic N and P released from surface-applied or incorporated PL. Poultry litter with or without acidified biochars was surface-applied or incorporated into the soil and incubated for 21 d. Volatilized NH3 was determined by trapping it in acid. Inorganic N and P were determined by leaching the soil with 0.01 M of CaCl2 during the study and by extracting it with 1 M KCl after incubation. Acidified biochars reduced NH3 losses by 58 to 63% with surface-applied PL, and by 56 to 60% with incorporated PL. Except for PH biochar, which caused a small increase in leached NH4 +-N with incorporated PL, acidified biochars had no effect on leached or KCl-extractable inorganic N and P from surface-applied or incorporated PL. These results suggest that acidified biochars may decrease NH3 losses from PL but may not reduce the potential for P loss in surface runoff from soils receiving PL. PMID:21655132

Saccharide-derived microporous spherical biochar prepared from hydrothermal carbonization and different pyrolysis temperatures: synthesis, characterization, and application in water treatment.

PubMed

Tran, Hai Nguyen; Lee, Chung-Kung; Nguyen, Tien Vinh; Chao, Huan-Ping

2017-08-24

Three saccharides (glucose, sucrose, and xylose) were used as pure precursors for synthesizing spherical biochars (GB, SB, and XB), respectively. The two-stage synthesis process comprised: (1) the hydrothermal carbonization of saccharides to produce spherical hydrochar' and (2) pyrolysis of the hydrochar at different temperatures from 300°C to 1200°C. The results demonstrated that the pyrolysis temperatures insignificantly affected the spherical morphology and surface chemistry of biochar. The biochar' isoelectric point ranged from 2.64 to 3.90 (abundant oxygen-containing functionalities). The Brunauer-Emmett-Teller (BET)-specific surface areas (S BET ) and total pore volumes (V total ) of biochar increased with the increasing pyrolysis temperatures. The highest S BET and V total were obtained at a pyrolysis temperature of 900°C for GB (775 m 2 /g and 0.392 cm 3 /g), 500°C for SB (410 m 2 /g and 0.212 cm 3 /g), and 600°C for XB (426 m 2 /g and 0.225 cm 3 /g), respectively. The spherical biochar was a microporous material with approximately 71-98% micropore volume. X-ray diffraction results indicated that the biochar' structure was predominantly amorphous. The spherical biochar possessed the graphite structure when the pyrolysis temperature was higher than 600°C. The adsorption capacity of GB depended strongly on the pyrolysis temperature. The maximum Langmuir adsorption capacities ([Formula: see text]) of 900GB exhibited the following selective order: phenol (2.332 mmol/g) > Pb 2+ (1.052 mmol/g) > Cu 2+ (0.825 mmol/g) > methylene green 5 (0.426 mmol/g) > acid red 1 (0.076 mmol/g). This study provides a simple method to prepare spherical biochar - a new and potential adsorbent for adsorbing heavy metals and aromatic contaminants.

Biochar applied at an appropriate rate can avoid increasing NH3 volatilization dramatically in rice paddy soil.

PubMed

Feng, Yanfang; Sun, Haijun; Xue, Lihong; Liu, Yang; Gao, Qian; Lu, Kouping; Yang, Linzhang

2017-02-01

Biochar application can increase carbon sequestration and reduce greenhouse gases emissions in paddy soils. However, its influence on ammonia (NH 3 ) volatilization is neglected. This soil column study was conducted using two biochars (wheat straw pyrolyzed at 500 °C and 700 °C) with two application rates (0.5 wt% and 3 wt%) to evaluate their impact on NH 3 volatilization from rice paddy. Results showed that biochar application did not change NH 3 volatilization fluxes pattern after N fertilization. Four biochar treatments recorded higher NH 3 volatilization (20.50-31.88 kg N ha -1 ) compared with the control (18.65 kg N ha -1 ). Especially, two 3 wt% biochar treatments had significantly 40.8-70.9% higher NH 3 volatilization than control. After the basal and first supplementary fertilization, the floodwater pH values were 7.61-7.79 and 7.51-7.76 under biochar treatments, higher than control (7.37 and 7.16, respectively). Meanwhile, after three split N fertilizations, the pH of surface soil received biochar increased by 0.19-0.45, 0.19-0.39, and 0.01-0.21 units, in comparison with the control soil. Furthermore, 3 wt% biochar treatments had higher floodwater and surface soil pH values than 0.5 wt% biochar treatments. Higher NH 4 + -N and lower NO 3 - -N concentrations of surface soil under biochar application were observed compared with control at tillering stage, whereas they were at similar level at jointing stage. The increased NH 3 volatilization at 3 wt% biochar treatments is attributed to increased pH of surface floodwater and soil, and reduced nitrification processes induced by biochar application. Biochar should be applied at lower rate to rice paddy soil, considering the NH 3 volatilization. Copyright © 2016 Elsevier Ltd. All rights reserved.

Towards a sustainable paradigm of waste-to-energy process: Enhanced anaerobic digestion of sludge with woody biochar

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shen, Yanwen; Linville, Jessica L.; Ignacio-de Leon, Patricia Anne A.

This study presents an integrated waste-to-energy process, using two waste streams, sludge generated from the municipal wastewater treatment plants (WWTPs) and biochar generated from the biomass gasification systems, to produce fungible biomethane and nutrient-rich digestate with fertilizer value. Two woody biochar, namely pinewood (PBC) and white oak biochar (WOBC) were used as additives during anaerobic digestion (AD) of WWTP sludge to enhance methane production at mesophilic and thermophilic temperatures. The PBC and WOBC have porous structure, large surface area and desirable chemical properties to be used as AD amendment material to sequester CO2 from biogas in the digester. The biochar-amendedmore » digesters achieved average methane content in biogas of up to 92.3% and 79.0%, corresponding to CO2 sequestration by up to 66.2% and 32.4% during mesophilic and thermophilic AD, respectively. Biochar addition enhanced process stability by increasing the alkalinity, but inhibitory effects were observed at high dosage. It also alleviated free ammonia inhibition by up to 10.5%. The biochar-amended digesters generated digestate rich in macro- and micronutrients including K (up to 300 m/L), Ca (up to 750 mg/L), Mg (up to 1800 mg/L) and Fe (up to 390 mg/L), making biochar-amended digestate a potential alternative used as agricultural lime fertilizer.« less

Organic coating on biochar explains its nutrient retention and stimulation of soil fertility.

PubMed

Hagemann, Nikolas; Joseph, Stephen; Schmidt, Hans-Peter; Kammann, Claudia I; Harter, Johannes; Borch, Thomas; Young, Robert B; Varga, Krisztina; Taherymoosavi, Sarasadat; Elliott, K Wade; McKenna, Amy; Albu, Mihaela; Mayrhofer, Claudia; Obst, Martin; Conte, Pellegrino; Dieguez-Alonso, Alba; Orsetti, Silvia; Subdiaga, Edisson; Behrens, Sebastian; Kappler, Andreas

2017-10-20

Amending soil with biochar (pyrolized biomass) is suggested as a globally applicable approach to address climate change and soil degradation by carbon sequestration, reducing soil-borne greenhouse-gas emissions and increasing soil nutrient retention. Biochar was shown to promote plant growth, especially when combined with nutrient-rich organic matter, e.g., co-composted biochar. Plant growth promotion was explained by slow release of nutrients, although a mechanistic understanding of nutrient storage in biochar is missing. Here we identify a complex, nutrient-rich organic coating on co-composted biochar that covers the outer and inner (pore) surfaces of biochar particles using high-resolution spectro(micro)scopy and mass spectrometry. Fast field cycling nuclear magnetic resonance, electrochemical analysis and gas adsorption demonstrated that this coating adds hydrophilicity, redox-active moieties, and additional mesoporosity, which strengthens biochar-water interactions and thus enhances nutrient retention. This implies that the functioning of biochar in soil is determined by the formation of an organic coating, rather than biochar surface oxidation, as previously suggested.

Comparison between Soil- and Biochar-Derived Humic Acids: Composition, Conformation, and Phenanthrene Sorption.

PubMed

Jin, Jie; Sun, Ke; Yang, Yan; Wang, Ziying; Han, Lanfang; Wang, Xiangke; Wu, Fengchang; Xing, Baoshan

2018-02-20

Biochar-derived organic matter (BDOM) plays an important role in determining biochar's application potential in soil remediation. However, little is known about the physicochemical properties of BDOM and its sorption of hydrophobic organic compounds (HOCs). Humic acids (HAs) were extracted from oxidized biochars produced from plant straws and animal manures at 450 °C, and their sorption of phenanthrene, a representative of HOCs, was investigated. The organic carbon recovery of biochar-derived HAs (BDHAs) was 13.9-69.3%. The 13 C NMR spectra of BDHAs mainly consisted of aromatic and carboxylic C, while those of soil-derived HAs (SDHAs) contained abundant signals in aliphatic region. BDHAs and SDHAs had comparable CO 2 cumulative surface areas. BDHAs were found to exhibit higher phenanthrene sorption than SDHAs. After the removal of amorphous aromatic components, the logK oc values of BDHAs were significantly decreased, implying that amorphous aromatic C regulated phenanthrene sorption by BDHAs. In contrast, aliphatic moieties dominated phenanthrene sorption by SDHAs, as evidenced by the enhanced sorption after the removal of amorphous aromatics. This study clearly demonstrated the contrasting characteristics and sorption behaviors of BDHA and SDHA, indicating that biochar addition and subsequent weathering could greatly affect native organic matter properties and the fate of HOCs in biochar-amended soils.

Efficacy of woody biomass and biochar for alleviating heavy metal bioavailability in serpentine soil.

PubMed

Bandara, Tharanga; Herath, Indika; Kumarathilaka, Prasanna; Hseu, Zeng-Yei; Ok, Yong Sik; Vithanage, Meththika

2017-04-01

Crops grown in metal-rich serpentine soils are vulnerable to phytotoxicity. In this study, Gliricidia sepium (Jacq.) biomass and woody biochar were examined as amendments on heavy metal immobilization in a serpentine soil. Woody biochar was produced by slow pyrolysis of Gliricidia sepium (Jacq.) biomass at 300 and 500 °C. A pot experiment was conducted for 6 weeks with tomato (Lycopersicon esculentum L.) at biochar application rates of 0, 22, 55 and 110 t ha -1 . The CaCl 2 and sequential extractions were adopted to assess metal bioavailability and fractionation. Six weeks after germination, plants cultivated on the control could not survive, while all the plants were grown normally on the soils amended with biochars. The most effective treatment for metal immobilization was BC500-110 as indicated by the immobilization efficiencies for Ni, Mn and Cr that were 68, 92 and 42 %, respectively, compared to the control. Biochar produced at 500 °C and at high application rates immobilized heavy metals significantly. Improvements in plant growth in biochar-amended soil were related to decreasing in metal toxicity as a consequence of metal immobilization through strong sorption due to high surface area and functional groups.

Effects of water washing and torrefaction pretreatments on rice husk pyrolysis by microwave heating.

PubMed

Zhang, Shuping; Dong, Qing; Zhang, Li; Xiong, Yuanquan; Liu, Xinzhi; Zhu, Shuguang

2015-10-01

The influences of water washing, torrefaction and combined water washing-torrefaction pretreatments on microwave pyrolysis of rice husk samples were investigated. The results indicated that the process of combined water washing-torrefaction pretreatment could effectively remove a large portion of inorganics and improve the fuel characteristics to a certain extent. The gas products were rich in combustible compositions and the syngas quality was improved by pretreatment process. The liquid products contained less moisture content, acids and furans, while more concentrated phenols and sugars from microwave pyrolysis of rice husk after pretreatments, especially after the combined water washing-torrefaction pretreatment. Biochar, produced in high yield, has the alkaline pH (pH 8.2-10.0) and high surface area (S(BET) 157.81-267.84 m(2)/g), they have the potential to be used as soil amendments. It is noteworthy that water washing increased the pore surface area of biochar, but torrefaction reduced the pore surface area. Copyright © 2015 Elsevier Ltd. All rights reserved.

Phosphorus recovery from biogas fermentation liquid by Ca-Mg loaded biochar.

PubMed

Fang, Ci; Zhang, Tao; Li, Ping; Jiang, Rongfeng; Wu, Shubiao; Nie, Haiyu; Wang, Yingcai

2015-03-01

Shortage in phosphorus (P) resources and P wastewater pollution is considered as a serious problem worldwide. The application of modified biochar for P recovery from wastewater and reuse of recovered P as agricultural fertilizer is a preferred process. This work aims to develop a calcium and magnesium loaded biochar (Ca-Mg/biochar) application for P recovery from biogas fermentation liquid. The physico-chemical characterization, adsorption efficiency, adsorption selectivity, and postsorption availability of Ca-Mg/biochar were investigated. The synthesized Ca-Mg/biochar was rich in organic functional groups and in CaO and MgO nanoparticles. With the increase in synthesis temperature, the yield decreased, C content increased, H content decreased, N content remained the same basically, and BET surface area increased. The P adsorption of Ca-Mg/biochar could be accelerated by nano-CaO and nano-MgO particles and reached equilibrium after 360min. The process was endothermic, spontaneous, and showed an increase in the disorder of the solid-liquid interface. Moreover, it could be fitted by the Freundlich model. The maximum P adsorption amounts were 294.22, 315.33, and 326.63mg/g. The P adsorption selectivity of Ca-Mg/biochar could not be significantly influenced by the typical pH level of biogas fermentation liquid. The nano-CaO and nano-MgO particles of Ca-Mg/biochar could reduce the negative interaction effects of coexisting ions. The P releasing amounts of postsorption Ca-Mg/biochar were in the order of Ca-Mg/B600>Ca-Mg/B450>Ca-Mg/B300. Results revealed that postsorption Ca-Mg/biochar can continually release P and is more suitable for an acid environment. Copyright © 2014. Published by Elsevier B.V.

Isolation and characterization of biochar-derived organic matter fractions and their phenanthrene sorption.

PubMed

Jin, Jie; Sun, Ke; Liu, Wei; Li, Shiwei; Peng, Xianqiang; Yang, Yan; Han, Lanfang; Du, Ziwen; Wang, Xiangke

2018-05-01

Chemical composition and pollutant sorption of biochar-derived organic matter fractions (BDOMs) are critical for understanding the long-term environmental significance of biochar. Phenanthrene (PHE) sorption by the humic acid-like (HAL) fractions isolated from plant straw- (PLABs) and animal manure-based (ANIBs) biochars, and the residue materials (RES) after HAL extraction was investigated. The HAL fraction comprised approximately 50% of organic carbon (OC) of the original biochars. Results of XPS and 13 C NMR demonstrated that the biochar-derived HAL fractions mainly consisted of aromatic clusters substituted by carboxylic groups. The CO 2 cumulative surface area of BDOMs excluding PLAB-derived RES fractions was obviously lower than that of corresponding biochars. The sorption nonlinearity of PHE by the fresh biochars was significantly stronger than that of the BDOM fractions, implying that the BDOM fractions were more chemically homogeneous. The BDOMs generally exhibited comparable or higher OC-normalized distribution coefficients (K oc ) of PHE than the original biochars. The PHE logK oc values of the fresh biochars correlated negatively with the micropore volumes due to steric hindrance effect. In contrast, a positive relationship between the sorption coefficients (K d ) of BDOMs and the micropore volumes was observed in this study, suggesting that pore filling could dominate PHE sorption by the BDOMs. The positive correlation between the PHE logK oc values of the HAL fractions and the aromatic C contents indicates that PHE sorption by the HAL fractions was regulated by aromatic domains. The findings of this study improve our knowledge of the evolution of biochar properties after application and its potential environmental impacts. Copyright © 2018 Elsevier Ltd. All rights reserved.

Characterization of upgraded hydrogel biochar from blended rice husk with coal fly ash

NASA Astrophysics Data System (ADS)

Ahmad, Nurul Farhana; Alias, Azil Bahari; Talib, Norhayati; Rashid, Zulkifli Abd; Ghani, Wan Azlina Wan Ab Karim

2017-12-01

Rice husk biochar (RB) blended with coal fly ash (CFA) is used as a material to develop hydrogel for heavy metal removal. This combination, namely hydrogel rice husk biochar-coal fly ash (HRB-CFA) composite is synthesized by embedding the biochar into acrylamide (AAM) as monomer, with N,N'-Methylenebisacrylamide (MBA) as crosslinker and ammonium persulfate (APS) as initiator. While activated carbon (AC) remains an expensive material, HRB-CFA is attracting great interest for its use in the absorption of organic contaminants due to its low material cost and importance as renewable source for securing future energy supply in the environmental system. Although the CFA does not have the surface area as high as AC, certain metallic components that are naturally present in the CFA can play the catalytic role in the removal of heavy metal from wastewater. The percentage of heavy metal removal is depends on the parameters that influence the sorption process; the effect of pH solution, dosage of adsorbent, initial concentration of solution, and contact time. The aim of this study is to characterize HRB-CFA by performing several analyses such as the Brunauer-Emmett-Teller (BET), thermogravimetric (TGA) and field emission scanning electron microscopy (FESEM) methods. The results obtained revealed that the best hydrogel ratio is 0.5:0.5 of blended RB and CFA, as proven by BET surface area, pore volume and pore size of 3.5392 m2/g, 0.00849 cm3/g and 90.566 Å, and the surface morphology showed an increase in porosity size.

Enhancement of chromate reduction in soils by surface modified biochar.

PubMed

Mandal, Sanchita; Sarkar, Binoy; Bolan, Nanthi; Ok, Yong Sik; Naidu, Ravi

2017-01-15

Chromium (Cr) is one of the common metals present in the soils and may have an extremely deleterious environmental impact depending on its redox state. Among two common forms, trivalent Cr(III) is less toxic than hexavalent Cr(VI) in soils. Carbon (C) based materials including biochar could be used to alleviate Cr toxicity through converting Cr(VI) to Cr(III). Incubation experiments were conducted to examine Cr(VI) reduction in different soils (Soil 1: pH 7.5 and Soil 2: pH 5.5) with three manures from poultry (PM), cow (CM) and sheep (SM), three respective manure-derived biochars (PM biochar (PM-BC), CM biochar (CM-BC) and SM biochar (SM-BC)) and two modified biochars (modified PM-BC (PM-BC-M) and modified SM-BC (SM-BC-M)). Modified biochar was synthesized by incorporating chitosan and zerovalent iron (ZVI) during pyrolysis. Among biochars, highest Cr(VI) reduction was observed with PM-BC application (5%; w/w) (up to 88.12 mg kg -1 ; 45% reduction) in Soil 2 (pH 5.5). The modified biochars enhanced Cr(VI) reduction by 55% (SM-BC-M) compared to manure (29%, SM) and manure-derived biochars (40% reduction, SM-BC). Among the modified biochars, SM-BC-M showed a higher Cr(VI) reduction rate (55%) than PM-BC-M (48%) in Soil 2. Various oxygen-containing surface functional groups such as phenolic, carboxyl, carbonyl, etc. on biochar surface might act as a proton donor for Cr(VI) reduction and subsequent Cr(III) adsorption. This study underpins the immense potential of modified biochar in remediation of Cr(VI) contaminated soils. Copyright © 2016 Elsevier Ltd. All rights reserved.

Self-activation of biochar from furfural residues by recycled pyrolysis gas.

PubMed

Yin, Yulei; Gao, Yuan; Li, Aimin

2018-04-17

Biochar samples with controllable specific surface area and mesopore ratio were self-activated from furfural residues by recycled pyrolysis gas. The objective of this study was to develop a new cyclic utilization method for the gas produced by pyrolysis. The influences of preparation parameters on the resulting biochar were studied by varying the pyrolysis-gas flow rate, activation time and temperature. Structural characterization of the produced biochar was performed by analysis of nitrogen adsorption isotherms at 77 K and scanning electron microscope (SEM). The pyrolysis gas compositions before and after activation were determined by a gas chromatograph. The results indicated that the surface area of the biochar was increased from 167 m 2 /g to 567 m 2 /g, the total pore volume increased from 0.121 cm 3 /g to 0.380 cm 3 /g, and the ratio of the mesopore pore volume to the total pore volume increased 17-39.7%. The CO volume fraction of the pyrolysis gas changed from 34.66 to 62.29% and the CO 2 volume fraction decreased from 48.26% to 12.17% under different conditions of pyrolysis-gas flow rate, activation time and temperature. The calorific values of pyrolysis gas changed from 8.82 J/cm 3 to 14.00 J/cm 3 , which were higher than those of conventional pyrolysis gases. The slower pyrolysis-gas flow rate and higher activation time increased the efficiency of the reaction between carbon and pyrolysis gas. These results demonstrated the feasibility of treatment of the furfural residues to produce microporous and mesoporous biochar. The pyrolysis gas that results from the activation process could be used as fuel. Overall, this new self-activation method meets the development requirements of cyclic economy and cleaner production. Copyright © 2018. Published by Elsevier Ltd.

Production of biochar out of organic urban waste to amend salt affected soils in the basin of Mexico

NASA Astrophysics Data System (ADS)

Chavez Garcia, Elizabeth; Siebe, Christina

2016-04-01

Biochar is widely recognized as an efficient tool for carbon sequestration and soil fertility. The understanding of its chemical and physical properties, strongly related to the biomass and production conditions, is central to identify the most suitable application of biochar. On the other hand, salt affected soils reduce the value and productivity of extensive areas worldwide. One feasible option to recover them is to add organic amendments, which improve water holding capacity and increase sorption sites for cations as sodium. The former lake Texcoco in the basin of Mexico has been a key area for the control of surface run-off and air quality of Mexico City. However, the high concentrations of soluble salts in their soils do not allow the development of a vegetation cover that protects the soil from wind erosion, being the latter the main cause of poor air quality in the metropolitan area during the dry season. On the other hand, the population of the city produces daily 2000 t of organic urban wastes, which are currently composted. Thus, we tested if either compost or biochar made out of urban organic waste can improve the salt affected soils of former lake Texcoco to grow grass and avoid wind erosion. We examined the physico-chemical properties of biochar produced from urban organic waste under pyrolysis conditions. We also set up a field experiment to evaluate the addition of these amendments into the saline soils of Texcoco. Our preliminary analyses show biochar yield was ca. 40%, it was mainly alkaline (pH: 8-10), with a moderate salt content (electrical conductivity: 0.5-3 mS/cm). We show also results of the initial phase of the field experiment in which we monitor the electrical conductivity, pH, water content, water tension and soil GHG fluxes on small plots amended with either biochar or compost in three different doses.

Effect of biochar produced at different pyrolysis temperature on the soil respiration of abandoned mine soil

NASA Astrophysics Data System (ADS)

Kim, Yong Seong; Kim, Juhee; Hwang, Wonjae; Hyun, Seunghun

2015-04-01

Contaminated soils near an abandoned mine site included the high acidic mine tailing have received great interest due to potential risk to human health, because leachable elements in low pH continuously release from mine site soil with ground water and precipitation event. Biochar, which is the obtained pyrolysis process of biomass, is used as a soil amendments and carbon storage. Especially, many researchers report that the biochar application to soil show increasing soil pH, CEC, adsorption capacity of various elements, as well as, enhanced microbial activity. Therefore, biochar application to contaminated soil near abandoned mine site is expected to have a positive effects on management of these site and soils through the decreased leachability of contaminants. However, effects of biochar application to these site on the soil respiration, as a common measure of soil health, are poorly understood. The objective of this study is to evaluate the effects of biochar application to abandoned mine site soil on the microbial activity with soil respiration test. Biochar was obtained from giant Miscanthus in a slow pyrolysis process (heating rate of 10° C min-1 and N2 gas flow rate of 1.2 L min-1) at the temperature of 400° C (BC4) and 700° C (BC7), respectively. All biochar samples were prepared with grinding and sieving for particle size control (150~500μm). Soil sample was collected from abandoned mine site at Korea (36° 58'N, 128° 10'E). Main contaminants of this soil were As (12.5 g kg-1), Pb (7.3 g kg-1), and Zn (1.1 g kg-1). Biochars were applied (5% by dry weight) to the soil (final mixture weight were 800g), and then moisture contents were adjusted to 100% field capacity (-0.33 bar) in the respirometer with vacuum pump. CO2 efflux of each samples was continuously assessed using continuous aeration system (air flow rate 25 cc min-1) using air cylinder during 130hr (at 20° C and darkness condition). The CO2 emitted from the samples were carried to the infrared gas sensor, and these data were sent to a data logger. During the measuring periods, the cumulative CO2 emission were similar between the control (516.8 mg-CO2 kg-1-soil) and BC4 5% mixture (519.3 mg-CO2 kg-1-soil), while BC7 5% mixture was significantly decreased (356.1 mg-CO2 kg-1-soil) compared to other treatment and control. Because the degradation rate of biochar generally increased with decreasing pyrolysis temperature, this result suggest that the soil respiration rates of biochar amended soils are affected by physico-chemical properties of biochar during early incubation periods (about 1 weeks), For example, surface properties of used biochars, which are related to adsorption of soil organic matter and CO2, have different properties with pyrolysis temperature such as specific surface area (BC4=5.08 m2g-1; BC7=260.75 m2 g-1, respectively), average pore diameter (BC4=4,673 nm; BC7=2,606 nm, respectively), and functional groups of biochar surface. However, there was not clear evidence of biochar-mine soil interaction process, because of the short observation periods. Future work should focus on the adsorption of CO2 and soil organic matter of biochar and soil-biochar interaction with long time periods and various biological test.

Composting-derived organic coating on biochar enhances its affinity to nitrate

NASA Astrophysics Data System (ADS)

Hagemann, Nikolas; Joseph, Stephen; Conte, Pellegrino; Albu, Mihaela; Obst, Martin; Borch, Thomas; Orsetti, Silvia; Subdiaga, Edisson; Behrens, Sebastian; Kappler, Andreas

2017-04-01

Biochar is defined charcoal that is produced by the thermal treatment of biomass in the (partial) absence of oxygen (pyrolysis) for non-oxidative applications, especially in agriculture. Due to its high surface area and porous structure, it is suggested as a beneficial soil amendment to increase crop yields and to tailor biogeochemical cycles in agro-ecosystems to reduce both greenhouse gas emissions and nutrient leaching. While early research focused on single applications of large amounts of biochar (>10 t ha-1), economic and ecological boundaries as well as practical considerations and recent findings shifted the focus towards low-dose (˜1 t ha-1) and potentially repeated applications of nutrient-enriched biochars, i.e. biochar-based fertilizers in the root-zone. Thus, biochar must be "loaded" with nutrients prior to its use as a root-zone amendment. Co-composting is suggested as a superior method, as co-composted biochar was shown to promote plant growth and showed the desired slow release of nutrients such as nitrate ("nitrate capture", Kammann et al., 2015 SR5:11080). However, the underlying mechanisms are not understood and nitrate capture has been quantified only for isolated biochars but not for e.g. biochar-amended composts without prior separation of the biochar. In the present study, we used repeated extractions with 2 M KCl and found that up to 30% of the nitrate present in a biochar-amended compost is captured in biochar, although biochar was amended to the initial composting feedstock (manure) only at 4% (w/w). Additionally, we quantified nitrate capture by pristine biochar after soaking the biochar in NH4NO3 solution in the absence of any additional organic carbon and nitrate capture of separated co-composted biochar. Assuming pseudo-first order kinetics for biochar nitrate release, we found an increase of biochar's affinity to nitrate after co-composting. Spectro-microscopical investigations (scanning transmission electron microscopy with electron energy loss spectroscopy - STEM-EELS, scanning transmission X-ray microscopy STXM) revealed the formation of a nano-porous organic coating on co-composted biochar. This coating alters the interaction of biochar with water as evidenced by proton fast field cycling nuclear magnetic resonance (1H FFC NMR) relaxometry and might explain its distinct characteristics. Our findings offer a roadmap for future research to design sustainable slow-release nitrogen fertilizers based on biochar to reduce the environmental impact of agriculture. Further microscopic studies are necessary to understand the preconditions of the formation of organic coatings on biochar on a holistic basis to design biochar post-production treatments.

Molecular characterization of biochars and their influence on microbiological properties of soil

USDA-ARS?s Scientific Manuscript database

The composition and surface chemistry of carbon rich biochar materials is highly uncertain and believed to change with feedstock and biomass conversion process. The tentative connection between the biochar surface chemical properties and their influence on microbially mediated mineralization of C, N...

Use of nuclear receptor luciferase-based bioassays to detect endocrine active chemicals in a biosolids-biochar amended soil.

PubMed

Anderson, Carolyn G; Joshi, Geetika; Bair, Daniel A; Oriol, Charlotte; He, Guochun; Parikh, Sanjai J; Denison, Michael S; Scow, Kate M

2017-08-01

Biosolids are a potentially valuable source of carbon and nutrients for agricultural soils; however, potential unintended impacts on human health and the environment must be considered. Virtually all biosolids contain trace amounts endocrine-disrupting chemicals derived from human use of pharmaceuticals and personal care products (PPCPs). One potential way to reduce the bioavailability of PPCPs is to co-apply biosolids with biochar to soil, because biochar's chemical (e.g., aromaticity) and physical properties (e.g., surface area) give it a high affinity to bind many organic chemicals in the environment. We developed a soil-specific extraction method and utilized a luciferase-based bioassay (CALUX) to detect endocrine active chemicals in a biosolids-biochar co-amendment soil greenhouse study. Both biochar (walnut shell, 900 °C) and biosolids had positive impacts on carrot and lettuce biomass accumulation over our study period. However, the walnut shell biochar stimulated aryl hydrocarbon receptor activity, suggesting the presence of potential endocrine active chemicals in the biochar. Since the biochar rate tested (100 t ha -1 ) is above the average agronomic rate (10-20 t ha -1 ), endocrine effects would not be expected in most environmental applications. The effect of high temperature biochars on endocrine system pathways must be explored further, using both quantitative analytical tools to identify potential endocrine active chemicals and highly sensitive bioanalytical assays such as CALUX to measure the resulting biological activity of such compounds. Copyright © 2017 Elsevier Ltd. All rights reserved.

Reduction of Bromate by Cobalt-Impregnated Biochar Fabricated via Pyrolysis of Lignin Using CO2 as a Reaction Medium.

PubMed

Cho, Dong-Wan; Kwon, Gihoon; Ok, Yong Sik; Kwon, Eilhann E; Song, Hocheol

2017-04-19

In this study, pyrolysis of lignin impregnated with cobalt (Co) was conducted to fabricate a Co-biochar (i.e., Co/lignin biochar) for use as a catalyst for bromate (BrO 3 - ) reduction. Carbon dioxide (CO 2 ) was employed as a reaction medium in the pyrolysis to induce desired effects associated with CO 2 ; (1) the enhanced thermal cracking of volatile organic compounds (VOCs) evolved from the thermal degradation of biomass, and (2) the direct reaction between CO 2 and VOCs, which resulted in the enhanced generation of syngas (i.e., H 2 and CO). This study placed main emphases on three parts: (1) the role of impregnated Co in pyrolysis of lignin in the presence of CO 2 , (2) the characterization of Co/lignin biochar, and (3) evaluation of catalytic capability of Co-lignin biochar in BrO 3 - reduction. The findings from the pyrolysis experiments strongly evidenced that the desired CO 2 effects were strengthened due to catalytic effect of impregnated Co in lignin. For example, the enhanced generation of syngas from pyrolysis of Coimpregnated lignin in CO 2 was more significant than the case without Co impregnation. Moreover, pyrolysis of Coimpregnated lignin in CO 2 led to production of biochar of which surface area (599 m 2 g -1 ) is nearly 100 times greater than the biochar produced in N 2 (6.6 m 2 g -1 ). Co/lignin biochar produced in CO 2 also showed a great performance in catalyzing BrO 3 - reduction as compared to the biochar produced in N 2 .

Functionalized biochar derived from heavy metal rich feedstock: Phosphate recovery and reusing the exhausted biochar as an enriched soil amendment.

PubMed

Mosa, Ahmed; El-Ghamry, Ayman; Tolba, Mona

2018-05-01

This paper provides a circular win-win approach for recycling rhizofiltration biomass into multifunctional engineered biochar for various environmental applications (e.g. phosphate recovery) with a potential reuse of the exhausted biochar as an enriched soil amendment. Functionalized biochars were derived from the disposals of water hyacinth (Eichhornia crassipes) plants grown in synthetic contaminated water spiked with either Fe 2+ (Fe-B), Mn 2+ (Mn-B), Zn 2+ (Zn-B) or Cu 2+ (Cu-B) comparing with the original drainage water as a control treatment (O-B). The in-situ functionalization of biochar via the inherently heavy metal-rich feedstock produced homogenous organo-mineral complexes on biochar matrix without environmental hazards (e.g. volatilization or chemical sludge formation) associated with other post-synthetic functionalization methods. Physicochemical analyses (SEM-EDS, XRD, FTIR, BET and zeta potential (ζ)) confirmed the functionalization of Fe-B, Zn-B and Cu-B due to organo-mineral complexes formation, maximizing specific surface area, lowering the electronegativity, originating positively charged functional groups, and thus improving the anion exchange capacity (AEC) comparing with O-B. In contrary, physicochemical characteristics of Mn-B was in similarity with those of O-B. Phosphate recovery by the functionalized biochar was much greater than that of the unfunctionalized forms (O-B and Mn-B). Precipitation was the dominant chemisorption mechanisms for phosphate sorption onto biochar compared to other mechanisms (ion exchange, electrostatic attraction and complexation with active functional groups). The exhausted biochar showed an ameliorating effect on the low water and nutrient supply potentials of sandy soil, and thus improved fresh biomass yield and nutritional status of maize seedlings with some restrictions on its high micronutrient content. Copyright © 2018 Elsevier Ltd. All rights reserved.

Rice (Oryza sativa L) plantation affects the stability of biochar in paddy soil.

PubMed

Wu, Mengxiong; Feng, Qibo; Sun, Xue; Wang, Hailong; Gielen, Gerty; Wu, Weixiang

2015-05-05

Conversion of rice straw into biochar for soil amendment appears to be a promising method to increase long-term carbon sequestration and reduce greenhouse gas (GHG) emissions. The stability of biochar in paddy soil, which is the major determining factor of carbon sequestration effect, depends mainly on soil properties and plant functions. However, the influence of plants on biochar stability in paddy soil remains unclear. In this study, bulk and surface characteristics of the biochars incubated without rice plants were compared with those incubated with rice plants using a suite of analytical techniques. Results showed that although rice plants had no significant influence on the bulk characteristics and decomposition rates of the biochar, the surface oxidation of biochar particles was enhanced by rice plants. Using (13)C labeling we observed that rice plants could significantly increase carbon incorporation from biochar into soil microbial biomass. About 0.047% of the carbon in biochar was incorporated into the rice plants during the whole rice growing cycle. These results inferred that root exudates and transportation of biochar particles into rice plants might decrease the stability of biochar in paddy soil. Impact of plants should be considered when predicting carbon sequestration potential of biochar in soil systems.

Rice (Oryza sativa L) plantation affects the stability of biochar in paddy soil

PubMed Central

Wu, Mengxiong; Feng, Qibo; Sun, Xue; Wang, Hailong; Gielen, Gerty; Wu, Weixiang

2015-01-01

Conversion of rice straw into biochar for soil amendment appears to be a promising method to increase long-term carbon sequestration and reduce greenhouse gas (GHG) emissions. The stability of biochar in paddy soil, which is the major determining factor of carbon sequestration effect, depends mainly on soil properties and plant functions. However, the influence of plants on biochar stability in paddy soil remains unclear. In this study, bulk and surface characteristics of the biochars incubated without rice plants were compared with those incubated with rice plants using a suite of analytical techniques. Results showed that although rice plants had no significant influence on the bulk characteristics and decomposition rates of the biochar, the surface oxidation of biochar particles was enhanced by rice plants. Using 13C labeling we observed that rice plants could significantly increase carbon incorporation from biochar into soil microbial biomass. About 0.047% of the carbon in biochar was incorporated into the rice plants during the whole rice growing cycle. These results inferred that root exudates and transportation of biochar particles into rice plants might decrease the stability of biochar in paddy soil. Impact of plants should be considered when predicting carbon sequestration potential of biochar in soil systems. PMID:25944542

Enhancing methane production from food waste fermentate using biochar: the added value of electrochemical testing in pre-selecting the most effective type of biochar.

PubMed

Cruz Viggi, Carolina; Simonetti, Serena; Palma, Enza; Pagliaccia, Pamela; Braguglia, Camilla; Fazi, Stefano; Baronti, Silvia; Navarra, Maria Assunta; Pettiti, Ida; Koch, Christin; Harnisch, Falk; Aulenta, Federico

2017-01-01

Recent studies have suggested that addition of electrically conductive biochar particles is an effective strategy to improve the methanogenic conversion of waste organic substrates, by promoting syntrophic associations between acetogenic and methanogenic organisms based on interspecies electron transfer processes. However, the underlying fundamentals of the process are still largely speculative and, therefore, a priori identification, screening, and even design of suitable biochar materials for a given biotechnological process are not yet possible. Here, three charcoal-like products (i.e., biochars) obtained from the pyrolysis of different lignocellulosic materials, (i.e., wheat bran pellets, coppiced woodlands, and orchard pruning) were tested for their capacity to enhance methane production from a food waste fermentate. In all biochar-supplemented (25 g/L) batch experiments, the complete methanogenic conversion of fermentate volatile fatty acids proceeded at a rate that was up to 5 times higher than that observed in the unamended (or sand-supplemented) controls. Fluorescent in situ hybridization analysis coupled with confocal laser scanning microscopy revealed an intimate association between archaea and bacteria around the biochar particles and provided a clear indication that biochar also shaped the composition of the microbial consortium. Based on the application of a suite of physico-chemical and electrochemical characterization techniques, we demonstrated that the positive effect of biochar is directly related to the electron-donating capacity (EDC) of the material, but is independent of its bulk electrical conductivity and specific surface area. The latter properties were all previously hypothesized to play a major role in the biochar-mediated interspecies electron transfer process in methanogenic consortia. Collectively, these results of this study suggest that for biochar addition in anaerobic digester operation, the screening and identification of the most suitable biochar material should be based on EDC determination, via simple electrochemical tests.

Degradation of dimethyl disulphide in soil with or without biochar amendment.

PubMed

Han, Dawei; Yan, Dongdong; Cao, Aocheng; Fang, Wensheng; Liu, Pengfei; Li, Yuan; Ouyang, Canbin; Wang, Qiuxia

2017-09-01

Dimethyl disulphide (DMDS) is a new and effective alternative to methyl bromide for soil fumigation. The effect of biochar on the fate of DMDS in soil is not fully understood. The objective of this study was to determine the degradation kinetics of DMDS in different soils and evaluate the effect of biochar amendment on DMDS degradation using incubation experiments. The degradation half-life of DMDS was between 1.05 and 6.66 days under non-sterile conditions, and 12.63 to 22.67 days under sterile conditions in five types of soil. Seven out of the eight tested biochar amendments (BC-2 to BC-8) delayed the degradation of DMDS in soil, increasing the half-life of DMDS in Fangshan soil from 1.05 to 1.16-5.87 days following amendment with 1% (w/w) biochar. The degradation rate of DMDS in Fangshan soil accelerated as the amendment rate of BC-1 increased, and decreased as the amendment rate of BC-7 increased. Biodegradation is an important degradation route for DMDS in soil, and DMDS degraded faster in alkaline soil. The effects of biochar amendments on DMDS degradation in soil are determined by complex multiple factors (such as surface area, pH and physicochemical composition), rather than by any single property of biochar. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Sorption Studies and Characterization of As (III) Adsorption over Developed Iron-Biochar Composites from Water.

NASA Astrophysics Data System (ADS)

Singh, P.; Mohan, D.

2016-12-01

Problem related to arsenic occurrence in groundwater has caused severe threat to human health in worldwide. Thus there is an increasing demand to find the chemistry and plausible mechanism of arsenic adsorption while remediating it from water. In present study iron-biochar composites are synthesised using agricultural waste materials. The rice husk iron-biochar composite (RIBC) and wheat husk iron-biochar composite (WIBC) were characterised and utilised for As (III) remediation from aqueous solution. The rice husk (RIBC) and wheat husk (WIBC) iron biochar composites were characterised. XPS, FT-IR, and XRD, were studied to analyse their elemental composition and functional group identification. While SEM, TEM, SEM-EDX were conducted to study their surface chemistry, mineralogy, porosity and crystallinity etc. Batch sorption studies were conducted for both rice husk (RIBC) and wheat husk (WIBC) iron-biochar composites to find sorption efficiency. Maximum As (III) adsorption was achieved in pH range 6-8 for both iron-biochar composites. Kinetic studies were conducted to establish the mechanism of As (III) adsorption at different dose and time. Optimum dose of 2g/L and 1g/L were reported for rice husk (RIBC) and wheat husk (WIBC) iron-biochar composites respectively. Electrostatic forces developed between arsenites and iron hydroxyl surface developed over the surface may have caused the removal of As (III). Significant amount of oxygen containing groups have been revealed through studies. Higher As (III) adsorption capacities were obtained for both iron-biochar composites to measure the amount of surface sites. Furthermore, various adsorption models are used to find the monolayer adsorption capacity. These findings suggest that developed iron-biochar composites may be used to remediate As (III) from contaminated water.

Arsenic sorption by red mud-modified biochar produced from rice straw.

PubMed

Wu, Chuan; Huang, Liu; Xue, Sheng-Guo; Huang, Yu-Ying; Hartley, William; Cui, Meng-Qian; Wong, Ming-Hung

2017-08-01

Red mud-modified biochar (RM-BC) has been produced to be utilized as a novel adsorbent to remove As because it can effectively combine the beneficial features of red mud (rich metal oxide composition and porous structure) and biochar (large surface area and porous structure properties). SEM-EDS and XRD analyses demonstrated that red mud had loaded successfully on the surface of biochar. With the increasing of pH in solution, arsenate (As(V)) adsorption on RM-BC decreased while arsenite (As(III)) increased. Arsenate adsorption kinetics process on RM-BC fitted the pseudo-second-order model, while that of As(III) favored the Elovich model. All sorption isotherms produced superior fits with the Langmuir model. RM-BC exhibited improved As removal capabilities, with a maximum adsorption capacity (Q max ) for As(V) of 5923 μg g -1 , approximately ten times greater than that of the untreated BC (552.0 μg g -1 ). Furthermore, it has been indicated that the adsorption of As(V) on RM-BC may be strongly associated with iron oxides (hematite and magnetite) and aluminum oxides (gibbsite) by X-ray absorption near-edge spectroscopy (XANES), which was possibly because of surface complexation and electrostatic interactions. RM-BC may be used as a valuable adsorbent for removing As in the environment due to the waste materials being relatively abundant.

HNO3 modified biochars for uranium (VI) removal from aqueous solution.

PubMed

Jin, Jie; Li, Shiwei; Peng, Xianqiang; Liu, Wei; Zhang, Chenlu; Yang, Yan; Han, Lanfang; Du, Ziwen; Sun, Ke; Wang, Xiangke

2018-05-01

The HNO 3 treatment was used to chemically modify the biochars produced from wheat straw (WH) and cow manure for U(VI) removal from aqueous solution. Macroscopic experiments proved that the enrichment of U(VI) on the biochars was regulated by surface complexation and electrostatic interactions. FTIR and XPS analyses confirmed that the highly efficient adsorption of U(VI) was due to the carboxyl groups on the biochar surfaces. The reducing agents of the R-CH 2 OH groups facilitated U(VI) adsorption on the untreated biochars. Owing to the higher contents of surface COO groups and more negative surface charge, the modified biochars showed enhanced U(VI) adsorption ability than the untreated ones. The maximum adsorption capacity of U(VI) by the oxidized WH was calculated to be 355.6 mg/g at pH 4.5 and 298 K, which was an improvement of 40 times relative to the untreated WH and was higher than that of most carbon-based adsorbents. Copyright © 2018 Elsevier Ltd. All rights reserved.

Characteristics of biochar: Microchemical properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Amonette, James E.; Joseph, Stephen

2009-03-13

Biochars, being derived from a variety of biological feedstocks that have been thermally degraded under a range of conditions, exhibit a correspondingly large range in composition and chemistry. Due in part to the somewhat chaotic nature of the thermal process itself, this chemical heterogeneity extends to the microscopic scale even within a single biochar. Thus, in the strictest sense, each biochar made under a particular feedstock/process combination presents a unique mixture of phases and microenvironments that gives rise to a unique set of chemical properties. In some respects, the chemical complexity of biochars rivals that of incipient soils. In thismore » chapter we focus on the chemical complexity of biochar as manifested primarily at a microscopic and molecular scale. We start by describing the biochar-formation process and how this influences the composition and nature of the solid phases, entrained oils, and their organization at the microscopic level. We then proceed to discuss the range of surface chemistries exhibited by biochars in terms of functional groups and electrochemical properties. We conclude with a discussion of the influence of these properties on the sorption of aqueous species at biochar surfaces.« less

Influence of Biochar on C and N Transformation in Soil and Their Impact on Greenhouse Gas Emissions

NASA Astrophysics Data System (ADS)

Chintala, R.; Schumacher, T. E.; Kumar, S.; Clay, D. E.; Malo, D. D.

2014-12-01

The capacity of pyrogenic biochar to mitigate soil surface exchange of greenhouse gases (GHG) is dependent on the influence of biochar on physiochemical transformations of C and N in soils. Incorporated biochar amendments are hypothesized to interfere with transformations of C and N as a result of the unique recalcitrant chemical structure and surface complexity of biochars. The nature of interference by biochar with C and N transformations are assumed to be dynamic not only due to their highly variable amphilicity inherited from feedstock source and controlled pyrolytic processing parameters but also to variation in soil factors. Experiments comprised of laboratory and field studies were designed to gain insight into the priming effect of incorporated non-native biochar materials on the transformations of C and N species in the soil. Molecular structure and surface functionality of plant based biochar materials produced from carbon optimized gasification of corn stover (Zea mays L.), Ponderosa pine (Pinus ponderosa Lawson and C. Lawson) wood residue, and switchgrass (Panicum virgatum L.) were studied in the laboratory using NMR and SEM-EdX. Biochar materials were found to be highly hydrophobic (low H/C values) with high aromaticity. The surface morphology of all the biochar materials was highly heterogeneous and pore size ranged from 1-22µm with the faces and edges of ordered sheets. In the field study, all the three biochar types were applied at a 1% (w/w) rate to a Maddock soil (Sandy, Mixed, Frigid Entic Hapludolls) located in an eroded upper landscape position and a Brookings soil (Fine-Silty, Mixed, Superactive, Frigid Pachic Hapludolls) located in a depositional landscape position. The crop rotation is a corn (Zea mays L.) followed by soybean (Glycine max L.). The priming effect of biochars on the transformations of C and N is determined by measuring the changes in soil C (total organic carbon, microbial biomass C, hydrolyzable C, and δ 13C) and N pools (microbial biomass N, inorganic N, and δ 15N). Greenhouse gas fluxes (CO2, CH4, and N2O) were measured and correlation studies will be conducted to determine the relationship with the interference effect of biochars on C and N transformation in soil. Initial data shows that biochar has an impact especially on CO2, and N2O emissions.

[Properties of maize stalk biochar produced under different pyrolysis temperatures and its sorption capability to naphthalene].

PubMed

Huang, Hua; Wang, Ya-Xiong; Tang, Jing-Chun; Tang, Jing-Chun; Zhu, Wen-Ying

2014-05-01

Biochar was made from maize stalk under three different temperatures of 300, 500 and 700 degreeC. The elemental composition of biochar was measured by elemental analyzer. Scanning electron microscope (SEM) was used to measure the surface morphology. Sorption of naphthalene to biochar was researched by batch sorption experiments. Results showed that, with the increase of temperature, C content increased from 66. 79% to 76. 30% , H and O contents decreased from 4.92% and 19. 25% to 3. 18% and 9.53%, respectively; H/C, O/C, (O + N)/C, aromaticity and hydrophobicity increased, and polarity decreased. SEM results showed that maize stalk biochar was platy particles, and its roughness of surface increased with increasing temperature. The sorption of naphthalene on biochar followed the Lagergren pseudo-second order dynamic sorption model. Initial sorption rate and equilibrium sorption capacity increased as preparation temperatures increased at the same initial concentration of naphthalene. The isotherm sorption behavior can be described by the Freundlich model, which indicated that, as pyrolysis temperature increased, the sorption capacity of biochar increased, and nonlinearity increased first and then decreased. Biochar derived from maize stalk had distinct features when compared with other feedstocks, and its elemental composition, surface features and sorption behaviors were significantly influenced by pyrolysis temperature.

Leaching of Mixtures of Biochar and Fly Ash

DOE Office of Scientific and Technical Information (OSTI.GOV)

Palumbo, Anthony Vito; Porat, Iris; Phillips, Jana Randolph

2009-01-01

Increasing atmospheric levels of greenhouse gases, especially CO2, and their effects on global temperature have led to interest in the possibility of carbon storage in terrestrial environments.2, 5, 6 Both the residual char from biomass pyrolysis7-9, 12 (biochar) and fly ash from coal combustion1, 13, 14 have the potential to significantly expand terrestrial sequestration options. Both biochar and fly ash also have potentially beneficial effects on soil properties. Fly ash has been shown to increase porosity, water-holding capacity, pH, conductivity, and dissolved SO42-, CO32-, Cl- and basic cations.10, 11, 16 Adding biochar to soil generally raises pH, increases total nitrogenmore » and total phosphorous, encourages greater root development, improves cation exchange capacity and reduces available aluminum.3, 17 Combinations of these benefits likely lead to the observed increased yields for crops including corn and sugarcane.17 with biochar addition to soil. In addition, it has been found that soils with added biochar emit lower amounts of other greenhouse gases (methane and nitrous oxide) 8, 17 than do unammended soils. Biochar and fly ash amendments may be useful in promoting terrestrial carbon sequestration on currently underutilized and degraded lands. For example, about 1% of the US surface lands consist of previously mined lands or highway rights-of-way.18 Poorly managed lands could count for another 15% of US area. Biochar and fly ash amendments could increase productivity of these lands and increase carbon storage in the soil Previous results showed minimal leaching of organic carbon and metals from a variety of fly ashes.15 Here, we are examining the properties of mixtures of biochar, fly ash, and soil and evaluating leaching of organic carbon and metals from the mixtures.« less

Biochar as enhancement material in natural attenuation systems

NASA Astrophysics Data System (ADS)

Kirmizakis, P.; Doherty, R.; Mendonça, C. A.; Costeira, R.; Allen, C.; Kulakov, L.

2017-12-01

Bioelectrochemical systems (BESs) have gained increasingly popularity over the last years especially in monitoring and clean-up of contaminants. BES are systems that combine wastewater treatment with energy production and resource recovery by harness the electro-activity of microorganisms. BESs consist of two electrodes, an anode and a cathode, separated with a proton-exchange membrane and an external electrical circuit which permits the passage of electrons generated at the anode to the cathode. Here we present a speed up of this natural breakdown process by providing a place to capture the anaerobic contaminants onto Biochar which captures the contaminants and also acts like a high surface area electrode passing electrons to the aerobic environments. For the purpose of this project, identical graphite and Teflon cells were constructed to compare and determine whether a Biochar BES was more efficient than a standard BES and more efficient than Biochar as sorption agent. Current production monitoring used as a real-time view of the process. The Biochar BES out performed both the BES and the Biochar BES in reduction of contaminants across the board. Our results suggest that the maximum growth and electro-activity of the microbial community occurred in the Biochar BES. This is in agreement with microbial findings which suggests that Biochar BES has a less diverse population which is more focused towards degradation and electroactive activity. For further understanding of the results, further geochemical analysis performed to provide additional insight on the process. This works shows clearly the applicability and efficiency of biochar among other electrode and sorption materials and electrical monitoring is versatile experimental tool to the remediation process and can be used as a non-destructive way to indirectly reveal process leading in understanding basic fundamental physical behaviours under specific experimental conditions.

Factors affecting transport of bacteria and microspheres through biochar-amended soils

USDA-ARS?s Scientific Manuscript database

We have investigated the role of biochar feedstock type (poultry litter extract and pine chips), biochar pyrolysis temperature (350 and 700 oC), biochar application rate (1, 2, and 10%), soil moisture content (saturated and 50% saturation), soil texture (1 and 12 % clay content), and surface propert...

Characteristics of and sorption to biochars derived from waste material

NASA Astrophysics Data System (ADS)

Sun, Huichao; Kah, Melanie; Sigmund, Gabriel; Hofmann, Thilo

2015-04-01

Biochars can exhibit a high sorption potential towards heavy metals and organic contaminants in various environmental matrices (e.g., water, soil). They have therefore been proposed for environmental remediation purposes to sequester contaminants. To date, most studies have focused on the physicochemical and sorption properties of mineral phases poor biochars, which are typically produced from plant residues. Only little knowledge is available for biochars derived from human and animal waste material, which are typically characterized by high mineral contents (e.g., sewage sludge, manure). Using human and animal waste as source material to produce biochars would support the development of attractive combined strategies for waste management and remediation. The potential impact of mineral phases on the physicochemical and sorption properties of biochars requires further studies so that the potential as sorbent material can be evaluated. With this purpose, different source material biochars were produced at 200°C, 350°C and 500°C, to yield a series of biochars representing a range of mineral content. The derived biochars from wood shavings (<1% ash), sewage sludge (50-70% ash) and pig manure (30-60% ash), as well as a commercial biochar derived from grain husks (40% ash), were extensively characterized (e.g., element composition, surface area, porosity, Fourier transform infrared spectroscopy). The contents of potentially toxic elements (i.e., heavy metals and polycyclic aromatic hydrocarbons) of all materials were within the guidelines values proposed by the International Biochar Initiative, indicating their suitability for environmental application. Single point sorption coefficients for the model sorbate pyrene were measured to investigate the effect of mineral content, feedstock, pyrolysis temperature, particle size fractions and acid demineralization on sorption behavior. Overall, sorption of pyrene was strong for all materials (4 < Log Kd < 6.5 L/kg). Sorption generally increased with increasing pyrolysis temperature but there was no effect of particle size on sorption affinity. For mineral phase rich biochars, sorption generally increased after acid demineralization. When considering all materials together, the sorbent aromaticity (hydrogen-carbon ratio) was the most important factor controlling sorption of pyrene. Overall, the study demonstrates that biochars derived from human and animal waste material and exhibiting high mineral contents have potential for remediation applications.

Physical and chemical characterizations of biochars derived from different agricultural residues

NASA Astrophysics Data System (ADS)

Jindo, K.; Mizumoto, H.; Sawada, Y.; Sanchez-Monedero, M. A.; Sonoki, T.

2014-08-01

Biochar has received large attention as a strategy to tackle against carbon emission. Not only carbon fixation has been carried out but also other merits for agricultural application due to unique physical and chemical character such as absorption of contaminated compounds in soil, trapping ammonia and methane emission from compost, and enhancement of fertilizer quality. In our study, different local waste feed stocks (rice husk, rice straw, wood chips of apple tree (Malus Pumila) and oak tree (Quercus serrata)), in Aomori, Japan, were utilized for creating biochar with different temperature (400-800 °C). Concerning to the biochar production, the pyrolysis of lower temperature had more biochar yield than higher temperature pyrolysis process. On the contrary, surface areas and adsorption characters have been increased as increasing temperature. The proportions of carbon content in the biochars also increased together with increased temperatures. Infrared-Fourier spectra (FT-IR) and 13C-NMR were used to understand carbon chemical compositions in our biochars, and it was observed that the numbers of the shoulders representing aromatic groups, considered as stable carbon structure appeared as the temperature came closer to 600 °C, as well as in FT-IR. In rice materials, the peak assigned to SiO2, was observed in all biochars (400-800 °C) in FT-IR. We suppose that the pyrolysis at 600 °C creates the most recalcitrant character for carbon sequestration, meanwhile the pyrolysis at 400 °C produces the superior properties as a fertilizer by retaining volatile and easily labile compounds which promotes soil microbial activities.

[Effects of biochar application on the abundance and structure of ammonia-oxidizer communities in coal-mining area.

PubMed

Liu, Yuan; Zhu, Ji Rong; Wu, Yu Chen; Shu, Liang Zuo

2017-10-01

As a new type of soil amendment, biochar can effectively improve soil fertility, structure and soil nitrogen transformation. We studied the effects of biochar application on soil properties, abundance and community structure of ammonia oxidizer in coal-mining area. The results showed that the biochar application significantly increased contents of soil NH4+-N, total nitrogen, available phosphorus and potassium. Compared with the control, no change in the abundance of ammonia-oxidizing archaea (AOA) was found under biochar treatment, but there was a significant increase in the abundance of ammonia-oxidizing bacteria (AOB). The analysis of T-RFLP profiles showed that biochar significantly increased the diversity indexes of AOA and AOB, and altered the community structure of both AOA and AOB. Improved soil nutrients as well as increased abundance and diversity of ammonia-oxidizing community to some extent indicated the potential of biochar application in reclamation of coal-mining area soil.

Fast nitrate and fluoride adsorption and magnetic separation from water on α-Fe2O3 and Fe3O4 dispersed on Douglas fir biochar.

PubMed

Bombuwala Dewage, Narada; Liyanage, Achala S; Pittman, Charles U; Mohan, Dinesh; Mlsna, Todd

2018-05-02

α-Fe 2 O 3 and Fe 3 O 4 dispersed on high surface area (663 m 2 /g) Douglas fir biochar (BC) was prepared for fast nitrate and fluoride ion removal from water using magnetic separations. This biochar, made originally at 900 °C, was impregnated with FeCl 3 and converted by pyrolysis at 600 °C to magnetic (494 m 2 /g) biochar (MBC). MBC and its precursor BC were characterized using SEM, SEM-EDX, STEM, S BET , PZC measurements, XRD analysis, and XPS. Dispersed α-Fe 2 O 3 and Fe 3 O 4 particles caused magnetization and generated most adsorption sites, causing more nitrate and fluoride uptake than BC. Both nitrate and fluoride adsorption on MBC remained high over a pH range from 2 to 10. Sorption was evaluated from 298 to 318 K using the Langmuir and Freundlich isotherm models. Langmuir adsorption capacities were 15 mg/g for nitrate and 9 mg/g for fluoride, higher capacities than those reported for other biochar and iron oxide adsorbents. Published by Elsevier Ltd.

Biochar affected by composting with farmyard manure.

PubMed

Prost, Katharina; Borchard, Nils; Siemens, Jan; Kautz, Timo; Séquaris, Jean-Marie; Möller, Andreas; Amelung, Wulf

2013-01-01

Biochar applications to soils can improve soil fertility by increasing the soil's cation exchange capacity (CEC) and nutrient retention. Because biochar amendment may occur with the applications of organic fertilizers, we tested to which extent composting with farmyard manure increases CEC and nutrient content of charcoal and gasification coke. Both types of biochar absorbed leachate generated during the composting process. As a result, the moisture content of gasification coke increased from 0.02 to 0.94 g g, and that of charcoal increased from 0.03 to 0.52 g g. With the leachate, the chars absorbed organic matter and nutrients, increasing contents of water-extractable organic carbon (gasification coke: from 0.09 to 7.00 g kg; charcoal: from 0.03 to 3.52 g kg), total soluble nitrogen (gasification coke: from not detected to 705.5 mg kg; charcoal: from 3.2 to 377.2 mg kg), plant-available phosphorus (gasification coke: from 351 to 635 mg kg; charcoal: from 44 to 190 mg kg), and plant-available potassium (gasification coke: from 6.0 to 15.3 g kg; charcoal: from 0.6 to 8.5 g kg). The potential CEC increased from 22.4 to 88.6 mmol kg for the gasification coke and from 20.8 to 39.0 mmol kg for the charcoal. There were little if any changes in the contents and patterns of benzene polycarboxylic acids of the biochars, suggesting that degradation of black carbon during the composting process was negligible. The surface area of the biochars declined during the composting process due to the clogging of micropores by sorbed compost-derived materials. Interactions with composting substrate thus enhance the nutrient loads but alter the surface properties of biochars. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Albedo impact on the suitability of biochar systems to mitigate global warming.

PubMed

Meyer, Sebastian; Bright, Ryan M; Fischer, Daniel; Schulz, Hardy; Glaser, Bruno

2012-11-20

Biochar application to agricultural soils can change the surface albedo which could counteract the climate mitigation benefit of biochar systems. However, the size of this impact has not yet been quantified. Based on empirical albedo measurements and literature data of arable soils mixed with biochar, a model for annual vegetation cover development based on satellite data and an assessment of the annual development of surface humidity, an average mean annual albedo reduction of 0.05 has been calculated for applying 30-32 Mg ha(-1) biochar on a test field near Bayreuth, Germany. The impact of biochar production and application on the carbon cycle and on the soil albedo was integrated into the greenhouse gas (GHG) balance of a modeled pyrolysis based biochar system via the computation of global warming potential (GWP) characterization factors. The analysis resulted in a reduction of the overall climate mitigation benefit of biochar systems by 13-22% due to the albedo change as compared to an analysis which disregards the albedo effect. Comparing the use of the same quantity of biomass in a biochar system to a bioenergy district heating system which replaces natural gas combustion, bioenergy heating systems achieve 99-119% of the climate benefit of biochar systems according to the model calculation.

Assessment of addition of biochar to filtering mixtures for potential water pollutant removal.

PubMed

Piscitelli, Lea; Rivier, Pierre-Adrien; Mondelli, Donato; Miano, Teodoro; Joner, Erik J

2018-01-01

Green roofs are used increasingly to alleviate peaks of water discharge into the sewage systems in urban areas. Surface runoff from roofs contain pollutants from dry and wet deposition, and green roofs offer a possibility to reduce the amounts of pollutants in the water discharged from roofs by degradation and filtering. These pollutants would otherwise enter wastewater treatments plants and ultimately end up in sewage sludge that is spread on agricultural soils. The most common substrates used in green roofs have limited capacity for filtration and sorption. Also, more sustainable alternatives are sought, due to the high carbon footprint of these materials. Biochar is a carbon-rich material produced by pyrolysis of biomass, and several types of biochar have been described as good sorbents and filter materials. Biochar is also a light and carbon negative material, which may fulfill other desired criteria for new green roof substrates. We here report on an experiment where two types of biochar, produced from olive husks at 450 °C or from forest waste at 850 ° C were mixed with volcanic rock or peat, and tested for retention capacity of phenanthrene and six heavy metals in a column experiment with unsaturated gravimetric water flow lasting for 3 weeks. The results suggest that biochar as a component in green roof substrates perform better than traditional materials, concerning retention of the tested pollutants, and that different types of biochar have different properties in this respect.

Insights into the attenuated sorption of organic compounds on black carbon aged in soil.

PubMed

Luo, Lei; Lv, Jitao; Chen, Zien; Huang, Rixiang; Zhang, Shuzhen

2017-12-01

Sorption of organic compounds on fresh black carbons (BCs) can be greatly attenuated in soil over time. We examined herein the changes in surface properties of maize straw-derived BCs (biochars) after aged in a black soil and their effects on the sorptive behaviors of naphthalene, phenanthrene and 1,3-dinitrobenzene. Dissolved fulvic and humic acids extracted from the soil were used to explore the role of dissolved organic carbon (DOC) in the aging of biochars. Chromatography analysis indicated that DOC molecules with relatively large molecular weight were preferentially adsorbed on the biochars during the aging processes. DOC sorption led to blockage of the biochar's micropores according to N 2 and CO 2 adsorption analyses. Surface chemistry of the biochars was also substantially modified, with more O-rich functional groups on the aged biochars compared to the original biochars, as evidenced by Near-edge X-ray absorption fine structure (NEXAFS) spectroscopy and X-ray photoelectron spectroscopy (XPS) analyses. The changes in both the physical and chemical surface properties of biochars by DOC led to significant attenuation of the sorption capacity and nonlinearity of the nonionic organic compounds on the aged biochars. Among the tested organic compounds, phenanthrene was the most attenuated in its sorption by the aging treatments, possibly because of its relatively large molecular size and hydrophobicity. The information can help gain a mechanistic understanding of interactions between BCs and organic compounds in soil environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Using heat-treated starch to modify the surface of biochar and improve the tensile properties of biochar-filled stryene-butadiene rubber composites

USDA-ARS?s Scientific Manuscript database

Heat-treated starch is a renewable material that can be used to modify the surface chemistry of small particles. In this work, heat-treated starch was used to coat hydrophilic biochar particles in order to make them more hydrophobic. Then when added as filler to hydrophobic styrene-butadiene rubber,...

Chemical and physical properties of Paulownia elongata biochar modified with oxidants for horticultural applications

USDA-ARS?s Scientific Manuscript database

Treatment of biochar with oxidants such as acids and hydrogen peroxide has been shown to alter porosity, increase adsorption of chemicals, and introduce functional groups on the biochar surfaces, all of which are desirable for their use in horticultural applications. Biochar was produced from the py...

An insight into the adsorption of diclofenac on different biochars: Mechanisms, surface chemistry, and thermodynamics.

PubMed

Lonappan, Linson; Rouissi, Tarek; Kaur Brar, Satinder; Verma, Mausam; Surampalli, Rao Y

2018-02-01

Biochars were prepared from feedstocks pinewood and pig manure. Biochar microparticles obtained through grinding were evaluated for the removal of emerging contaminant diclofenac (DCF) and the underlying mechanism were thoroughly studied. Characterization of biochar was carried out using particle size analyzer, SEM, BET, FT-IR, XRD, XPS and zeta potential instrument. Pig manure biochar (BC-PM) exhibited excellent removal efficiency (99.6%) over pine wood biochar (BC-PW) at 500 µg L -1 of DCF (environmentally significant concentration). Intraparticle diffusion was found to be the major process facilitated the adsorption. BC-PW followed pseudo first-order kinetics whereas BC-PM followed pseudo second-order kinetics. Pine wood biochar was largely affected by pH variations whereas for pig manure biochar, pH effects were minimal owing to its surface functional groups and DCF hydrophobicity. Thermodynamics, presence of co-existing ions, initial adsorbate concentration and particles size played substantial role in adsorption. Various isotherms models were also studied and results are presented. Copyright © 2017 Elsevier Ltd. All rights reserved.

Pyrolysis of attapulgite clay blended with yak dung enhances pasture growth and soil health: Characterization and initial field trials.

PubMed

Rafiq, Muhammad Khalid; Joseph, Stephen D; Li, Fei; Bai, Yanfu; Shang, Zhanhuan; Rawal, Aditya; Hook, James M; Munroe, Paul R; Donne, Scott; Taherymoosavi, Sara; Mitchell, David R G; Pace, Ben; Mohammed, Mohanad; Horvat, Joseph; Marjo, Christopher E; Wagner, Avital; Wang, Yanlong; Ye, Jun; Long, Rui-Jun

2017-12-31

Recent studies have shown that the pyrolysis of biomass combined with clay can result in both lower cost and increase in plant yields. One of the major sources of nutrients for pasture growth, as well as fuel and building materials in Tibet is yak dung. This paper reports on the initial field testing in a pasture setting in Tibet using yak dung, biochar, and attapulgite clay/yak dung biochars produced at ratios of 10/90 and 50/50 clay to dung. We found that the treatment with attapulgite clay/yak dung (50/50) biochar resulted in the highest pasture yields and grass nutrition quality. We also measured the properties and yields of mixtures of clay/yak dung biochar used in the field trials produced at 400°C and 500°C to help determine a possible optimum final pyrolysis temperature and dung/clay ratio. It was observed that increasing clay content increased carbon stability, overall biochar yield, pore size, carboxyl and ketone/aldehyde functional groups, hematite and ferrous/ferric sulphate/thiosulphate concentration, surface area and magnetic moment. Decreasing clay content resulted in higher pH, CEC, N content and an enhanced ability to accept and donate electrons. The resulting properties were a complex function of both processing temperature and the percentage of clay for the biochars processed at both 400°C and 500°C. It is possible that the increase in yield and nutrient uptake in the field trial is related to the higher concentration of C/O functional groups, higher surface area and pore volume and higher content of Fe/O/S nanoparticles of multiple oxidation state in the 50/50 clay/dung. These properties have been found to significantly increase the abundance of beneficial microorganisms and hence improve the nutrient cycling and availability in soil. Further field trials are required to determine the optimum pyrolysis production conditions and application rate on the abundance of beneficial microorganisms, yields and nutrient quality. Copyright © 2017 Elsevier B.V. All rights reserved.

[Priming effect of biochar on the minerialization of native soil organic carbon and the mechanisms: A review.

PubMed

Chen, Ying; Liu, Yu Xue; Chen, Chong Jun; Lyu, Hao Hao; Wa, Yu Ying; He, Li Li; Yang, Sheng Mao

2018-01-01

In recent years, studies on carbon sequestration of biochar in soil has been in spotlight owing to the specific characteristics of biochar such as strong carbon stability and well developed pore structure. However, whether biochar will ultimately increase soil carbon storage or promote soil carbon emissions when applied into the soil? This question remains controversial in current academic circles. Further research is required on priming effect of biochar on mineralization of native soil organic carbon and its mechanisms. Based on the analysis of biochar characteristics, such as its carbon composition and stability, pore structure and surface morphology, research progress on the priming effect of biochar on the decomposition of native soil organic carbon was reviewed in this paper. Furthermore, possible mechanisms of both positive and negative priming effect, that is promoting and suppressing the mineralization, were put forward. Positive priming effect is mainly due to the promotion of soil microbial activity caused by biochar, the preferential mineralization of easily decomposed components in biochar, and the co-metabolism of soil microbes. While negative priming effect is mainly based on the encapsulation and adsorption protection of soil organic matter due to the internal pore structure and the external surface of biochar. Other potential reasons for negative priming effect can be the stabilization resulted from the formation of organic-inorganic complex promoted by biochar in the soil, and the inhibition of activity of soil microbes and its enzymes by biochar. Finally, future research directions were proposed in order to provide theoretical basis for the application of biochar in soil carbon sequestration.

Environmental Impacts of Large Scale Biochar Application Through Spatial Modeling

NASA Astrophysics Data System (ADS)

Huber, I.; Archontoulis, S.

2017-12-01

In an effort to study the environmental (emissions, soil quality) and production (yield) impacts of biochar application at regional scales we coupled the APSIM-Biochar model with the pSIMS parallel platform. So far the majority of biochar research has been concentrated on lab to field studies to advance scientific knowledge. Regional scale assessments are highly needed to assist decision making. The overall objective of this simulation study was to identify areas in the USA that have the most gain environmentally from biochar's application, as well as areas which our model predicts a notable yield increase due to the addition of biochar. We present the modifications in both APSIM biochar and pSIMS components that were necessary to facilitate these large scale model runs across several regions in the United States at a resolution of 5 arcminutes. This study uses the AgMERRA global climate data set (1980-2010) and the Global Soil Dataset for Earth Systems modeling as a basis for creating its simulations, as well as local management operations for maize and soybean cropping systems and different biochar application rates. The regional scale simulation analysis is in progress. Preliminary results showed that the model predicts that high quality soils (particularly those common to Iowa cropping systems) do not receive much, if any, production benefit from biochar. However, soils with low soil organic matter ( 0.5%) do get a noteworthy yield increase of around 5-10% in the best cases. We also found N2O emissions to be spatial and temporal specific; increase in some areas and decrease in some other areas due to biochar application. In contrast, we found increases in soil organic carbon and plant available water in all soils (top 30 cm) due to biochar application. The magnitude of these increases (% change from the control) were larger in soil with low organic matter (below 1.5%) and smaller in soils with high organic matter (above 3%) and also dependent on biochar application rate.

Adsorption with Biochar or Activated Carbon as Treatment Processes for Greywater Reuse

NASA Astrophysics Data System (ADS)

Thompson, K.; Cook, S. M.; Summers, R. S.

2017-12-01

Nearly 3 billion people experience water scarcity in their watershed for at least one month every year. Population growth, urbanization, and global climate change are increasing the severity of water scarcity in many areas. Decentralized reuse of greywater from showers, baths, and bathroom sinks could reduce residential water demand by 35% and urban water demand by 15%. Decentralized greywater reuse could be environmentally sustainable due to less energy for pumping than centralized systems. However, decentralized greywater reuse presents challenges from economies of scale. Biochar can serve as a low-cost, environmentally sustainable alternative to activated carbon (AC) in water treatment. Many studies have explored biochar as a sorbent for surface water or wastewater, but studies about biochar for greywater treatment are limited. The objectives of this study were (1) to compare the performance of biochar and AC for sorption of dissolved organic carbon (DOC) in greywater and (2) to determine whether AC or biochar can satisfy greywater treatment regulations alone or in combination with other processes. Jar tests with doses ranges of 0.25 to 4 g/L were used to compare sorbents for DOC removal after various pretreatments. All sorbents were ground to ≤45 µm particle diameter. Five biochars were screened to select the most effective greywater sorbent. These biochars covered a range of production temperatures, feedstocks, and lab- and full-scale production. Wood-based forced draft top lit updraft biochar (FD-TLUD) biochar was found to be the most effective for DOC removal from both real and synthetic greywater. Sorption with FD-TLUD biochar or AC can remove up to 70% or 80% of DOC from greywater, respectively. AC sorption of DOC was only 1-10% greater at each dose from a greywater sample with 11 mg/L DOC than from a greywater sample with 43 mg/L DOC. Coagulation with 30 mg/L alum removed 14% of greywater DOC, and biochar or AC sorption removed similar percentages of DOC from microfiltered or coagulated greywater. UVA254 removal correlated strongly with DOC removal for both AC and biochar (R2=0.89). These results indicate that biochar could be useful component in greywater treatment systems. Future work will focus on sorption after other chemical and biological pretreatments.

Nutrient conservation during spent mushroom compost application using spent mushroom substrate derived biochar.

PubMed

Lou, Zimo; Sun, Yue; Bian, Shuping; Ali Baig, Shams; Hu, Baolan; Xu, Xinhua

2017-02-01

Spent mushroom compost (SMC), a spent mushroom substrate (SMS) derived compost, is always applied to agriculture land to enhance soil organic matter and nutrient contents. However, nitrogen, phosphate and organic matter contained in SMC can leach out and contaminate ground water during its application. In this study, biochars prepared under different pyrolytic temperatures (550 °C, 650 °C or 750 °C) from SMS were applied to soil as a nutrient conservation strategy. The resultant biochars were characterized for physical and mineralogical properties. Surface area and pore volume of biochars increased as temperature increased, while pore size decreased with increasing temperature. Calcite and quartz were evidenced by X-ray diffraction analysis in all biochars produced. Results of column leaching test suggested that mixed treatment of SMC and SMS-750-800 (prepared with the temperature for pyrolysis and activation was chosen as 750 °C and 800 °C, respectively) could reduce 43% of TN and 66% of COD Cr in leachate as compared to chemical fertilizers and SMC, respectively. Furthermore, increasing dosage of SMS-750-800 from 1% to 5% would lead to 54% COD Cr reduction in leachate, which confirmed its nutrient retention capability. Findings from this study suggested that combined application of SMC and SMS-based biochar was an applicable strategy for reducing TN and COD Cr leaching. Copyright © 2016 Elsevier Ltd. All rights reserved.

Adsorption Removal of 17β-Estradiol from Water by Rice Straw-Derived Biochar with Special Attention to Pyrolysis Temperature and Background Chemistry.

PubMed

Wang, Xiaohua; Liu, Ni; Liu, Yunguo; Jiang, Luhua; Zeng, Guangming; Tan, Xiaofei; Liu, Shaobo; Yin, Zhihong; Tian, Sirong; Li, Jiang

2017-10-11

Rice straw biochar that produced at three pyrolysis temperatures (400, 500 and 600 °C) were used to investigate the adsorption properties of 17β-estradiol (E2). The biochar samples were characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), elemental analysis and BET surface area measurements. The influences of pyrolysis temperature, E2 concentration, pH, ionic strength, background electrolyte and humic acid were studied. Kinetic and isotherm results illustrated that the adsorption process could be well described by pseudo-second-order and Freundlich models. Experimental results showed that ionic strength had less influence on the adsorption of E2 by 500 and 600 °C rice straw biochar. Further, multivalent ions had positive impact on E2 removal than monovalent ions and the influence of the pyrolysis temperature was unremarkable when background electrolyte existed in solutions. The adsorption capacity of E2 decreased with the pH ranged from 3.0 to 12.0 and the humic acid concentration from 2 to 10 mg L -1 . Electrostatic attractions and π-π interaction were involved in the adsorption mechanisms. Compared to low-temperature biochar, high-temperature biochar exhibited a better adsorption capacity for E2 in aqueous solution, indicated it had a greater potential for E2 pollution control.

Adsorption Removal of 17β-Estradiol from Water by Rice Straw-Derived Biochar with Special Attention to Pyrolysis Temperature and Background Chemistry

PubMed Central

Wang, Xiaohua; Liu, Ni; Liu, Yunguo; Jiang, Luhua; Zeng, Guangming; Tan, Xiaofei; Liu, Shaobo; Yin, Zhihong; Tian, Sirong; Li, Jiang

2017-01-01

Rice straw biochar that produced at three pyrolysis temperatures (400, 500 and 600 °C) were used to investigate the adsorption properties of 17β-estradiol (E2). The biochar samples were characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), elemental analysis and BET surface area measurements. The influences of pyrolysis temperature, E2 concentration, pH, ionic strength, background electrolyte and humic acid were studied. Kinetic and isotherm results illustrated that the adsorption process could be well described by pseudo-second-order and Freundlich models. Experimental results showed that ionic strength had less influence on the adsorption of E2 by 500 and 600 °C rice straw biochar. Further, multivalent ions had positive impact on E2 removal than monovalent ions and the influence of the pyrolysis temperature was unremarkable when background electrolyte existed in solutions. The adsorption capacity of E2 decreased with the pH ranged from 3.0 to 12.0 and the humic acid concentration from 2 to 10 mg L−1. Electrostatic attractions and π-π interaction were involved in the adsorption mechanisms. Compared to low-temperature biochar, high-temperature biochar exhibited a better adsorption capacity for E2 in aqueous solution, indicated it had a greater potential for E2 pollution control. PMID:29019933

Water repellency of two forest soils after biochar addition

Treesearch

D. S. Page-Dumroese; P. R. Robichaud; R. E. Brown; J. M. Tirocke

2015-01-01

Practical application of black carbon (biochar) to improve forest soil may be limited because biochar is hydrophobic. In a laboratory, we tested the water repellency of biochar application (mixed or surface applied) to two forest soils of varying texture (a granitic coarse-textured Inceptisol and an ash cap fine-textured Andisol) at four different application rates (0...

Influence of biochar on the physical, chemical and retention properties of an amended sandy soil

NASA Astrophysics Data System (ADS)

Baiamonte, Giorgio; De Pasquale, Claudio; Parrino, Francesco; Crescimanno, Giuseppina

2017-04-01

Soil porosity plays an important role in soil-water retention and water availability to crops, potentially affecting both agricultural practices and environmental sustainability. The pore structure controls fluid flow and transport through the soil, as well as the relationship between the properties of individual minerals and plants. Moreover, the anthropogenic pressure on soil properties has produced numerous sites with extensive desertification process close to residential areas. Biochar (biologically derived charcoal) is produced by pyrolysis of biomasses under low oxygen conditions, and it can be applied for recycling organic waste in soils and increase soil fertility, improving soil structure and enhancing soil water storage and soil water movement. Soil application of biochar might have agricultural, environmental and sustainability advantages over the use of organic manures or compost, as it is a porous material with a high inner surface area. The main objectives of the present study were to investigate the possible application of biochar from forest residues, derived from mechanically chipped trunks and large branches of Abies alba M., Larix decidua Mill., Picea excelsa L., Pinus nigra A. and Pinus sylvestris L. pyrolysed at 450 °C for 48h, to improve soil structural and hydraulic properties (achieving a stabilization of soil). Different amount of biochar were added to a desertic sandy soil, and the effect on soil porosity water retention and water available to crops were investigated. The High Energy Moisture Characteristic (HEMC) technique was applied to investigate soil-water retention at high-pressure head levels. The adsorption and desorption isotherms of N2 on external surfaces were also determined in order to investigate micro and macro porosity ratio. Both the described model of studies on adsorption-desorption experiments with the applied isotherms model explain the increasing substrate porosity with a particular attention to the macro and micro porosity, respectively.

Role of Inherent Inorganic Constituents in SO2 Sorption Ability of Biochars Derived from Three Biomass Wastes.

PubMed

Xu, Xiaoyun; Huang, Daxuan; Zhao, Ling; Kan, Yue; Cao, Xinde

2016-12-06

Biochar is rich in both organic carbon and inorganic components. Extensive work has attributed the high sorption ability of biochar to the pore structure and surface chemical property related to its organic carbon fraction. In this study, three biochars derived from dairy manure (DM-biochar), sewage sludge (SS-biochar), and rice husk (RH-biochar), respectively, were evaluated for their SO 2 sorption behavior and the underlying mechanisms, especially the role of inherent inorganic constituents. The sorption capacities of SO 2 by the three biochars were 8.87-15.9 mg g -1 . With the moisture content increasing from 0% to 50%, the sorption capacities increased by up to about 3 times, mainly due to the formation of alkaline water membrane on the biochar surface which could promote the sorption and transformation of acidic SO 2 . DM- and SS-biochar containing larger mineral constituents showed higher sorption capacity for SO 2 than RH-biochar containing less mineral components. CaCO 3 and Ca 3 (PO 4 ) 2 in DM-biochar induced sorbed SO 2 transformation into K 2 Ca(SO 4 ) 2 ·H 2 O and CaSO 4 ·2H 2 O, while the sorbed SO 2 was converted to Fe 2 (SO 4 ) 3 ·H 2 SO 4 ·2H 2 O, CaSO 4 ·2H 2 O, and Ca 3 (SO 3 ) 2 SO 4 ·12H 2 O in SS-biochar. For RH-biochar, K 3 H(SO 4 ) 2 might exist in the exhausted samples. Overall, the chemical transformation of SO 2 induced by biochar inherent mineral components occupied 44.6%-85.5% of the total SO 2 sorption. The results obtained from this study demonstrated that biochar as a unique carbonaceous material could distinctly be a promising sorbent for acidic SO 2 removal in which the inorganic components played an important role in the SO 2 sorption and transformation.

Recent developments of post-modification of biochar for electrochemical energy storage.

PubMed

Cheng, Bin-Hai; Zeng, Raymond J; Jiang, Hong

2017-12-01

Biochar is a common byproduct from thermochemical conversion of biomass to produce bioenergy. However, the biochar features, such as morphology, porosity and surface chemistry, cannot be well controlled in conventional conversion approaches, limiting the wide application of raw biochar. Aiming to meet the specific requirements, post-modification of raw biochar was frequently conducted to improve the quality. In this review, recent developments regarding post-modification methods of biochar are presented and discussed. Progresses on the applications of post modified biochar as electrode materials for supercapacitors are intensively summarized. This review aims to reveal the key factors that affecting the performance of biochar-based supercapacitors, and provide guidance for rationalizing the modification methods to expand the applications of biochar-based functional materials in supercapacitors. Copyright © 2017 Elsevier Ltd. All rights reserved.

Nutrient uptake by agricultural crops from biochar-amended soils: results from two field experiments in Austria

NASA Astrophysics Data System (ADS)

Karer, Jasmin; Zehetner, Franz; Kloss, Stefanie; Wimmer, Bernhard; Soja, Gerhard

2013-04-01

The use of biochar as soil amendment is considered as a promising agricultural soil management technique, combining carbon sequestration and soil fertility improvements. These expectations are largely founded on positive experiences with biochar applications to impoverished or degraded tropical soils. The validity of these results for soils in temperate climates needs confirmation from field experiments with typical soils representative for intensive agricultural production areas. Frequently biochar is mixed with other organic additives like compost. As these two materials interact with each other and each one may vary considerably in its basic characteristics, it is difficult to attribute the effects of the combined additive to one of its components and to a specific physico-chemical parameter. Therefore investigations of the amendment efficacy require the study of the pure components to characterize their specific behavior in soil. This is especially important for adsorption behavior of biochar for macro- and micronutrients because in soil there are multiple nutrient sinks that compete with plant roots for vital elements. Therefore this contribution presents results from a field amendment study with pure biochar that had the objective to characterize the macro- and microelement uptake of crops from different soils in two typical Austrian areas of agricultural production. At two locations in North and South-East Austria, two identical field experiments on different soils (Chernozem and Cambisol) were installed in 2011 with varying biochar additions (0, 30 and 90 t/ha) and two nitrogen levels. The biochar was a product from slow pyrolysis of wood (SC Romchar SRL). During the installation of the experiments, the biochar fraction of <2 mm was mixed with surface soil to a depth of 15 cm in plots of 33 m2 each (n=4). Barley (at the Chernozem soil) and maize (at the Cambisol) were cultivated according to standard agricultural practices. The highest crop yields at both study sites were observed after a biochar application rate of 90 t/ha and an abundant nitrogen supply (mineral N fertilizer rates: 120 kg/ha for barley, 150 kg/ha for corn). An omission of biochar addition at the same nitrogen addition rate resulted in a yield decrease of 10 % for barley although the total N uptake was 11 % higher but P and K uptake decreased by 14 and 6 %. This indicates that the higher yields with biochar were accompanied by increased availability of P and K but not N. The N deficiency treatment (with biochar amendment) resulted in yield decreases of 23 %, which were similar as the reductions of N uptake while reductions of P and K uptake were less pronounced. For corn, the omission of biochar caused only marginal yield effects (6%) and no significant changes in the N, P, and K uptake rates. Deficient N supply, however, resulted in severe yield reductions (46%) in spite of the high biochar application rate. The reductions of macronutrient uptake were in the same range for N (44%) but lower for P, K, Ca and Mg (19 to 33%). In summary, N and Cu were the elements that were least available for plant uptake at high biochar application rates.

Pyrolysis production of fruit peel biochar for potential use in treatment of palm oil mill effluent.

PubMed

Lam, Su Shiung; Liew, Rock Keey; Cheng, Chin Kui; Rasit, Nazaitulshila; Ooi, Chee Kuan; Ma, Nyuk Ling; Ng, Jo-Han; Lam, Wei Haur; Chong, Cheng Tung; Chase, Howard A

2018-05-01

Fruit peel, an abundant waste, represents a potential bio-resource to be converted into useful materials instead of being dumped in landfill sites. Palm oil mill effluent (POME) is a harmful waste that should also be treated before it can safely be released to the environment. In this study, pyrolysis of banana and orange peels was performed under different temperatures to produce biochar that was then examined as adsorbent in POME treatment. The pyrolysis generated 30.7-47.7 wt% yield of a dark biochar over a temperature ranging between 400 and 500 °C. The biochar contained no sulphur and possessed a hard texture, low volatile content (≤34 wt%), and high amounts of fixed carbon (≥72 wt%), showing durability in terms of high resistance to chemical reactions such as oxidation. The biochar showed a surface area of 105 m 2 /g and a porous structure containing mesopores, indicating its potential to provide many adsorption sites for use as an adsorbent. The use of the biochar as adsorbent to treat the POME showed a removal efficiency of up to 57% in reducing the concentration of biochemical oxygen demand (BOD), chemical oxygen demand COD, total suspended solid (TSS) and oil and grease (O&G) of POME to an acceptable level below the discharge standard. Our results indicate that pyrolysis shows promise as a technique to transform banana and orange peel into value-added biochar for use as adsorbent to treat POME. The recovery of biochar from fruit waste also shows advantage over traditional landfill approaches in disposing this waste. Copyright © 2018 Elsevier Ltd. All rights reserved.

Development of functional composts using spent coffee grounds, poultry manure and biochar through microbial bioaugmentation.

PubMed

Emmanuel, S Aalfin; Yoo, Jangyeon; Kim, Eok-Jo; Chang, Jae-Soo; Park, Young-In; Koh, Sung-Cheol

2017-11-02

Spent coffee grounds (SCG), poultry manure, and agricultural waste-derived biochar were used to manufacture functional composts through microbial bioaugmentation. The highest yield of tomato stalk-based biochar (40.7%) was obtained at 450°C with a surface area of 2.35 m 2 g -1 . Four pilot-scale composting reactors were established to perform composting for 45 days. The ratios of NH 4 + -N/NO 3 - -N, which served as an indicator of compost maturity, indicate rapid, and successful composting via microbial bioaugmentation and biochar amendment. Moreover, germination indices for radish also increased by 14-34% through augmentation and biochar amendment. Microbial diversity was also enhanced in the augmented and biochar-amended composts by 7.1-8.9%, where two species of Sphingobacteriaceae were dominant (29-43%). The scavenging activities of 2,2-diphenyl-1-picrylhydrazyl (DPPH) were enhanced by 14.1% and 8.6% in the fruits of pepper plants grown in the presence of the TR-2 (augmentation applied only) and TR-3 (both augmentation and biochar amendment applied) composts, respectively. Total phenolic content was also enhanced by 68% in the fruits of the crops grown in TR-3. Moreover, the other compost, TR-L (augmentation applied only), boosted DPPH scavenging activity by 111% in leeks compared with commercial organic fertilizer, while TR-3 increased the phenolic content by 44.8%. Composting facilitated by microbial augmentation and biochar amendment shortened the composting time and enhanced the quality of the functional compost. These results indicate that functional compost has great potential to compete with commercially available organic fertilizers and that the novel composting technology could significantly contribute to the eco-friendly recycling of organic wastes such as spent coffee grounds, poultry manure, and agricultural wastes.

A novel solid digestate-derived biochar-Cu NP composite activating H2O2 system for simultaneous adsorption and degradation of tetracycline.

PubMed

Fu, Dun; Chen, Zheng; Xia, Dong; Shen, Liang; Wang, Yuanpeng; Li, Qingbiao

2017-02-01

Solid digestate, a by-product of anaerobic digestion systems, has led to a range of environmental issues. In the present study, a novel composite based on a solid digestate-biochar-Cu NP composite was synthesized for tetracycline removal from an aqueous medium. The removal efficiency values for tetracycline (200 mg L -1 ) were 31.5% and 97.8%, respectively, by the biochar-Cu NP composite (0.5 g L -1 ) in the absence and presence of hydrogen peroxide (H 2 O 2 , 20 mM) within 6 h of reaction time. The possible degradation pathway of tetracycline was investigated using liquid chromatography-mass spectrometry. The desorption experiment results suggested that no significant concentration of tetracycline was detected on the composite after the reaction, but a small amount of intermediates in terms of total organic carbon (TOC) accounting for 3.1%, and 23.3% of the end-product NH 4 + was adsorbed onto the biochar sheets. The dispersive Cu NPs on the biochar resulted in an increase in the surface area and pore volume of the biochar-Cu NP composite, which enhanced tetracycline adsorption as well as the degradation efficiency. Relative tetracycline removal mechanisms were dominantly ascribed to ·OH generation from the Cu(II)/Cu(I) redox reaction with H 2 O 2 and the electron-transfer process of free radicals (FRs) in biochar. The proposed approach serves dual purposes of waste digestate reuse and treatment of antibiotic pollutants. This study highlights the activation of H 2 O 2 by the dispersive Cu NPs coupling with biochar derived from a waste solid digestate for tetracycline treatment. Copyright © 2016. Published by Elsevier Ltd.

Glyphosate sorption/desorption on biochars - interactions of physical and chemical processes.

PubMed

Hall, Kathleen E; Spokas, Kurt A; Gamiz, Beatriz; Cox, Lucia; Papiernik, Sharon K; Koskinen, William C

2018-05-01

Biochar, a carbon-rich product of biomass pyrolysis, could limit glyphosate transport in soil and remediate contaminated water. The present study investigates the sorption/desorption behavior of glyphosate on biochars prepared from different hardwoods at temperatures ranging from 350 to 900 °C to elucidate fundamental mechanisms. Glyphosate (1 mg L -1 ) sorption on biochars increased with pyrolysis temperature and was highest on 900 °C biochars; however, total sorption was low on a mass basis (<0.1 mg g -1 ). Sorption varied across feedstock materials, and isotherms indicated concentration dependence. Biochars with a greater fraction of micropores exhibited lower sorption capacities, and specific surface groups were also found to be influential. Prepyrolysis treatments with iron and copper, which complex glyphosate in soils, did not alter biochar sorption capacities. Glyphosate did not desorb from biochar with CaCl 2 solution; however, up to 86% of the bound glyphosate was released with a K 2 HPO 4 solution. Results from this study suggest a combined impact of surface chemistry and physical constraints on glyphosate sorption/desorption on biochar. Based on the observed phosphate-induced desorption of glyphosate, the addition of P-fertilizer to biochar-amended soils can remobilize the herbicide and damage non-target plants; therefore, improved understanding of this risk is necessary. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Synthesis optimization of oil palm empty fruit bunch and rice husk biochars for removal of imazapic and imazapyr herbicides.

PubMed

Yavari, Saba; Malakahmad, Amirhossein; Sapari, Nasiman B; Yavari, Sara

2017-05-15

Imidazolinones are a family of herbicides that are used to control a broad range of weeds. Their high persistence and leaching potential make them probable risk to the ecosystems. In this study, biochar, the biomass-derived solid material, was produced from oil palm empty fruit bunches (EFB) and rice husk (RH) through pyrolysis process. Feedstock and pyrolysis variables can control biochar sorption capacity. Therefore, the present study attempts to evaluate effects of three pyrolysis variables (temperature, heating rate and retention time) on abilities of biochars for removal of imazapic and imazapyr herbicides from soil. Response surface methodology (RSM) was used for optimizing the variables to achieve maximum sorption performance of the biochars. Experimental data were interpreted accurately by quadratic models. Based on the results, sorption capacities of both biochars raised when temperature decreased to 300 °C, mainly because of increased biochars effective functionality in sorption of polar molecules. Heating rate of 3°C/min provided optimum conditions to maximize the sorption capacities of both biochars. Retention time of about 1 h and 3 h were found to be the best for EFB and RH biochars, respectively. EFB biochar was more efficient in removal of the herbicides, especially imazapyr due to its chemical composition and higher polarity index (0.42) rather than RH biochar (0.39). Besides, higher cation exchange capacity (CEC) values of EFB biochar (83.90 cmol c /kg) in comparison with RH biochar (70.73 cmol c /kg) represented its higher surface polarity effective in sorption of the polar herbicides. Copyright © 2017 Elsevier Ltd. All rights reserved.

Removal of element mercury by medicine residue derived biochars in presence of various gas compositions.

PubMed

Li, Guoliang; Shen, Boxiong; Li, Yongwang; Zhao, Bin; Wang, Fumei; He, Chuan; Wang, Yinyin; Zhang, Min

2015-11-15

Pyrolyzed biochars from an industrial medicinal residue waste were modified by microwave activation and NH4Cl impregnation. Mercury adsorption of different modified biochars was investigated in a quartz fixed-bed reactor. The results indicated that both physisorption and chemisorption of Hg(0) occurred on the surface of M6WN5 which was modified both microwave and 5wt.% NH4Cl loading, and exothermic chemisorption process was a dominant route for Hg(0) removal. Microwave activation improved pore properties and NH4Cl impregnation introduced good active sites for biochars. The presence of NO and O2 increased Hg(0) adsorption whereas H2O inhibited Hg(0) adsorption greatly. A converse effect of SO2 was observed on Hg(0) removal, namely, low concentration of SO2 promoted Hg(0) removal obviously whereas high concentration of SO2 suppressed Hg(0) removal. The Hg(0) removal by M6WN5 was mainly due to the reaction of the C−Cl with Hg(0) to form HgCl2, and the active state of C−Cl(*) groups might be an intermediate group in this process. Thermodynamic analysis showed that mercury adsorption by the biochars was exothermic process and apparent adsorption energy was 43.3 kJ/mol in the range of chemisorption. In spite of low specific surface area, M6WN5 proved to be a promising Hg(0) sorbent in flue gas when compared with other sorbents. Copyright © 2015. Published by Elsevier B.V.

Arsenic removal by perilla leaf biochar in aqueous solutions and groundwater: An integrated spectroscopic and microscopic examination.

PubMed

Niazi, Nabeel Khan; Bibi, Irshad; Shahid, Muhammad; Ok, Yong Sik; Burton, Edward D; Wang, Hailong; Shaheen, Sabry M; Rinklebe, Jörg; Lüttge, Andreas

2018-01-01

In this study, we examined the removal of arsenite (As(III)) and arsenate (As(V)) by perilla leaf-derived biochars produced at 300 and 700 °C (referred as BC300 and BC700) in aqueous environments. Results revealed that the Langmuir isotherm model provided the best fit for As(III) and As(V) sorption, with the sorption affinity following the order: BC700-As(III) > BC700-As(V) > BC300-As(III) > BC300-As(V) (Q L  = 3.85-11.01 mg g -1 ). In general, As removal decreased (76-60%) with increasing pH from 7 to 10 except for the BC700-As(III) system, where notably higher As removal (88-90%) occurred at pH from 7 to 9. Surface functional moieties contributed to As sequestration by the biochars examined here. However, significantly higher surface area and aromaticity of BC700 favored a greater As removal compared to BC300, suggesting that surface complexation/precipitation dominated As removal by BC700. Arsenic K-edge X-ray absorption near edge structure (XANES) spectroscopy demonstrated that up to 64% of the added As(V) was reduced to As(III) in BC700- and BC300-As(V) sorption experiments, and in As(III) sorption experiments, partial oxidation of As(III) to As(V) occurred (37-39%). However, XANES spectroscopy was limited to precisely quantify As binding with sulfur species as As 2 S 3 -like phase. Both biochars efficiently removed As from natural As-contaminated groundwater (As: 23-190 μg L -1 ; n = 12) despite in the presence of co-occurring anions (e.g., CO 3 2- , PO 4 3- , SO 4 2- ) with the highest levels of As removal observed for BC700 (97-100%). Overall, this study highlights that perilla leaf biochars, notably BC700, possessed the greatest ability to remove As from solution and groundwater (drinking water). Significantly, the integrated spectroscopic techniques advanced our understanding to examine complex redox transformation of As(III)/As(V) with biochar, which are crucial to determine fate of As on biochar in aquatic environments. Copyright © 2017 Elsevier Ltd. All rights reserved.

Production of bio-oil and biochar from soapstock via microwave-assisted co-catalytic fast pyrolysis.

PubMed

Dai, Leilei; Fan, Liangliang; Liu, Yuhuan; Ruan, Roger; Wang, Yunpu; Zhou, Yue; Zhao, Yunfeng; Yu, Zhenting

2017-02-01

In this study, production of bio-oil and biochar from soapstock via microwave-assisted co-catalytic fast pyrolysis combining the advantages of in-situ and ex-situ catalysis was performed. The effects of catalyst and pyrolysis temperature on product fractional yields and bio-oil chemical compositions were investigated. From the perspective of bio-oil yield, the optimal pyrolysis temperature was 550°C. The use of catalysts reduced the water content, and the addition of bentonite increased the bio-oil yield. Up to 84.16wt.% selectivity of hydrocarbons in the bio-oil was obtained in the co-catalytic process. In addition, the co-catalytic process can reduce the proportion of oxygenates in the bio-oil to 15.84wt.% and eliminate the N-containing compounds completely. The addition of bentonite enhanced the BET surface area of bio-char. In addition, the bio-char removal efficiency of Cd 2+ from soapstock pyrolysis in presence of bentonite was 27.4wt.% higher than without bentonite. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparison of cadmium and lead sorption by Phyllostachys pubescens biochar produced under a low-oxygen pyrolysis atmosphere.

PubMed

Zhang, Chao; Shan, Baoqing; Tang, Wenzhong; Zhu, Yaoyao

2017-08-01

Phyllostachys pubescens (PP) biochars produced under a low oxygen pyrolysis atmosphere (oxygen content 1-4%) were prepared as sorbents for investigating the mechanisms of cadmium and lead sorption. A low-oxygen pyrolysis atmosphere increased biochar ash and specific surface area, promoting heavy metal precipitation and complexation. The maximum sorption capacity (Q m ) of Pb 2+ obtained from the Langmuir model was 67.4mg·g -1 , while Q m of Cd 2+ was 14.7mg·g -1 . The contribution of each mechanism varied with increasing oxygen content at a low pyrolysis temperature. Mineral precipitation with Pb 2+ was the predominant mechanism for Pb 2+ removal and the contribution proportion significantly increased from 17.2% to 71.7% as pyrolysis oxygen atmosphere increased from 0% to 4%. The results showed that cadmium sorption primarily involved coordination with π electrons, at 54.1-82.6% of the total adsorption capacity. The PP biochar shows potential for application in removing heavy metal contaminants, especially Pb 2+ . Copyright © 2017 Elsevier Ltd. All rights reserved.

Production of bio-fertilizer from microwave vacuum pyrolysis of waste palm shell for cultivation of oyster mushroom (Pleurotus ostreatus)

NASA Astrophysics Data System (ADS)

Lun Nam, Wai; Huan Su, Man; Phang, Xue Yee; Chong, Min Yee; Keey Liew, Rock; Ma, Nyuk Ling; Lam, Su Shiung

2017-11-01

Microwave vacuum pyrolysis of waste palm shell (WPS) was performed to produce biochar, which was then tested as bio-fertilizer in growing Oyster mushroom (Pleurotus ostreatus). The pyrolysis approach generated a biochar containing a highly porous structure with a high BET surface area (up to 1250 m2/g) and a low moisture content (≤ 10 wt%), exhibiting desirable adsorption properties to be used as bio-fertilizer since it can act as a housing that provides many sites on which living microorganisms (mycelium or plant-growth promoting bacteria) and organic nutrients can be attached or adsorbed onto. This could in turn stimulate plant growth by increasing the availability and supply of nutrients to the targeted host plant. The results from growing Oyster mushroom using the biochar record an impressive growth rate and a monthly production of up to about 550 g of mushroom. The shorter time for mycelium growth on whole baglog (30 days) and the highest yield of Oyster mushroom (550 g) was obtained from the cultivation medium added with 20 g of biochar. Our results demonstrate that the biochar-based bio-fertilizer produce from microwave vacuum pyrolysis of WPS show exceptional promise as an alternative growing substrate for mushroom cultivation.

Production of bio-fertilizer from microwave vacuum pyrolysis of palm kernel shell for cultivation of Oyster mushroom (Pleurotus ostreatus).

PubMed

Nam, Wai Lun; Phang, Xue Yee; Su, Man Huan; Liew, Rock Keey; Ma, Nyuk Ling; Rosli, Mohd Haqqi Nazilli Bin; Lam, Su Shiung

2018-05-15

Microwave vacuum pyrolysis of palm kernel shell (PKS) was performed to produce biochar, which was then tested as bio-fertilizer in growing Oyster mushroom (Pleurotus ostreatus). The pyrolysis approach produced biochar containing a highly porous structure with a high BET surface area of up to 270m 2 /g and low moisture content (≤10wt%), exhibiting desirable adsorption properties to be used as bio-fertilizer since it can act as a housing that provides many sites on which living microorganisms (mycelium or plant-growth promoting bacteria) and organic nutrients can be attached or adsorbed onto. This could in turn stimulate plant growth by increasing the availability and supply of nutrients to the targeted host plant. The results from growing Oyster mushroom using the biochar recorded an impressive growth rate and a monthly production of up to about 550g of mushroom. A shorter time for mycelium growth on one whole baglog (21days) and the highest yield of Oyster mushroom (550g) were obtained from cultivation medium added with 20g of biochar. Our results demonstrate that the biochar-based bio-fertilizer produced from microwave vacuum pyrolysis of PKS shows exceptional promise as growth promoting material for mushroom cultivation. Copyright © 2017 Elsevier B.V. All rights reserved.

Biochar as an electron shuttle for reductive dechlorination of pentachlorophenol by Geobacter sulfurreducens

PubMed Central

Yu, Linpeng; Yuan, Yong; Tang, Jia; Wang, Yueqiang; Zhou, Shungui

2015-01-01

The reductive dechlorination of pentachlorophenol (PCP) by Geobacter sulfurreducens in the presence of different biochars was investigated to understand how biochars affect the bioreduction of environmental contaminants. The results indicated that biochars significantly accelerate electron transfer from cells to PCP, thus enhancing reductive dechlorination. The promotion effects of biochar (as high as 24-fold) in this process depend on its electron exchange capacity (EEC) and electrical conductivity (EC). A kinetic model revealed that the surface redox-active moieties (RAMs) and EC of biochar (900 °C) contributed to 56% and 41% of the biodegradation rate, respectively. This work demonstrates that biochars are efficient electron mediators for the dechlorination of PCP and that both the EC and RAMs of biochars play important roles in the electron transfer process. PMID:26592958

Effects of biochar on the emissions, soil distribution, and nematode control of 1,3-dichloropropene

USDA-ARS?s Scientific Manuscript database

Application of a rice husk-derived biochar to the surface of a sandy loam soil chamber reduced soil-air emissions of 1,3-dichloropropene (1,3-D) from 42% in a control (no biochar) to 8%. The difference in emissions was due to adsorption of 1,3-D onto the biochar, measured as 32.5%. The remaining 1,3...

Biochar composite membrane for high performance pollutant management: Fabrication, structural characteristics and synergistic mechanisms.

PubMed

Ghaffar, Abdul; Zhu, Xiaoying; Chen, Baoliang

2018-02-01

Biochar, a natural sourced carbon-rich material, has been used commonly in particle shape for carbon sequestration, soil fertility and environmental remediation. Here, we report a facile approach to fabricate freestanding biochar composite membranes for the first time. Wood biochars pyrolyzed at 300 °C and 700 °C were blended with polyvinylidene fluoride (PVdF) in three percentages (10%, 30% and 50%) to construct membranes through thermal phase inversion process. The resultant biochar composite membranes possess high mechanical strength and porous structure with uniform distribution of biochar particles throughout the membrane surface and cross-section. The membrane pure water flux was increased with B300 content (4825-5411 ± 21 L m -2 h -1 ) and B700 content (5823-6895 ± 72 L m -2 h -1 ). The membranes with B300 were more hydrophilic with higher surface free energy (58.84-60.31 mJ m -2 ) in comparison to B700 (56.32-51.91 mJ m -2 ). The biochar composite membranes indicated promising adsorption capacities (47-187 mg g -1 ) to Rhodamine B (RhB) dye. The biochar membranes also exhibited high retention (74-93%) for E. coli bacterial suspensions through filtration. After simple physical cleaning, both the adsorption and sieving capabilities of the biochar composite membranes could be effectively recovered. Synergistic mechanisms of biochar/PVdF in the composite membrane are proposed to elucidate the high performance of the membrane in pollutant management. The multifunctional biochar composite membrane not only effectively prevent the problems caused by directly using biochar particle as sorbent but also can be produced in large scale, indicating great potential for practical applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

Efficacy of biochar to remove Escherichia coli from stormwater under steady and intermittent flow.

PubMed

Mohanty, Sanjay K; Cantrell, Keri B; Nelson, Kara L; Boehm, Alexandria B

2014-09-15

Biofilters, designed to facilitate the infiltration of stormwater into soil, are generally ineffective in removing bacteria from stormwater, thereby causing pollution of groundwater and receiving surface waters. The bacterial removal capacity of biofilters has been shown to be lower in the presence of natural organic matter (NOM) and during intermittent infiltration of stormwater. To improve the removal of fecal indicator bacteria (Escherichia coli) under these conditions, we amended sand with 5% (by weight) biochar, a carbonaceous geomedia produced by pyrolysis of biomass, and investigated the removal and remobilization of E. coli. Three types of biochar were used to evaluate the role of biochar properties on the removal. Compared to sand, biochar not only retained up to 3 orders of magnitude more E. coli, but also prevented their mobilization during successive intermittent flows. In the presence of NOM, the removal capacity of biochar was lower, but remained higher than sand alone. The improved retention with the biochar amendment is attributed to an increase in the attachment of E. coli at the primary minimum and to an increase in the water-holding capacity of biochar-amended sand, which renders driving forces such as moving air-water interfaces less effective in detaching bacteria from grain surfaces. Biochars with lower volatile matter and polarity appear to be more effective in removing bacteria from stormwater. Overall, our results suggest that a biochar amendment to biofilter media has the potential to effectively remove bacteria from stormwater. Copyright © 2014 Elsevier Ltd. All rights reserved.

Microstructural and associated chemical changes during the composting of a high temperature biochar: Mechanisms for nitrate, phosphate and other nutrient retention and release.

PubMed

Joseph, Stephen; Kammann, Claudia I; Shepherd, Jessica G; Conte, Pellegrino; Schmidt, Hans-Peter; Hagemann, Nikolas; Rich, Anne M; Marjo, Christopher E; Allen, Jessica; Munroe, Paul; Mitchell, David R G; Donne, Scott; Spokas, Kurt; Graber, Ellen R

2018-03-15

Recent studies have demonstrated the importance of the nutrient status of biochar and soils prior to its inclusion in particular agricultural systems. Pre-treatment of nutrient-reactive biochar, where nutrients are loaded into pores and onto surfaces, gives improved yield outcomes compared to untreated biochar. In this study we have used a wide selection of spectroscopic and microscopic techniques to investigate the mechanisms of nutrient retention in a high temperature wood biochar, which had negative effects on Chenopodium quinoa above ground biomass yield when applied to the system without prior nutrient loading, but positive effects when applied after composting. We have compared non-composted biochar (BC) with composted biochar (BCC) to elucidate the differences which may have led to these results. The results of our investigation provide evidence for a complex series of reactions during composting, where dissolved nutrients are first taken up into biochar pores along a concentration gradient and through capillary action, followed by surface sorption and retention processes which block biochar pores and result in deposition of a nutrient-rich organomineral (plaque) layer. The lack of such pretreatment in the BC samples would render it reactive towards nutrients in a soil-fertilizer system, making it a competitor for, rather than provider of, nutrients for plant growth. Copyright © 2017 Elsevier B.V. All rights reserved.

Adsorption behavior comparison of trivalent and hexavalent chromium on biochar derived from municipal sludge.

PubMed

Chen, Tan; Zhou, Zeyu; Xu, Sai; Wang, Hongtao; Lu, Wenjing

2015-08-01

In this work, static equilibrium experiments were conducted to distinguish the adsorption performance between the two valence states of chromium on biochar derived from municipal sludge. The removal capacity of Cr(VI) is lower than 7mg/g at the initial chromium concentration range of 50-200mg/L, whereas that of Cr(III) higher than 20mg/g. It indicates that Cr(III) is much easier to be stabilized than Cr(VI). No significant changes in the biochar surface functional groups are observed before and after the adsorption equilibrium, demonstrating the poor contribution of organic matter in chromium adsorption. The main mechanism of heavy metal adsorption by biochar involves (1) surface precipitation through pH increase caused by biochar buffer ability, and (2) exchange between cations in solution (Cd(2+)) and in biochar matrix (e.g. Ca(2+) and Mg(2+)). The reduction of Cr(VI) to Cr(III) is necessary to improve removal efficiency of chromium. Copyright © 2015 Elsevier Ltd. All rights reserved.

Biochar in vineyards: impact on soil quality and crop yield four years after the application

NASA Astrophysics Data System (ADS)

Ferreira, Carla; Verheijen, Frank; Puga, João; Keizer, Jacob; Ferreira, António

2017-04-01

Biochar is a recalcitrant organic carbon compound, created by biomass heating at high temperatures (300-1000°C) under low oxygen concentrations. Biochar application to agricultural soils has received increasing attention over the last years, due to its climate change mitigation and adaptation potential and reported improved soil properties and functions relevant to agronomic and environmental performance. Reported impacts are linked with increased cation exchange capacity, enhanced nutrient and water retention, and positive influences on soil microbial communities, which influence crop yields. Nevertheless, few studies have focused on mid-to-long term impacts of biochar application. This study investigated the impact of biochar on soil quality and crop yield four years after biochar application in a vineyard in North-Central Portugal. The site has a Mediterranean climate with a strong Atlantic Ocean influence, with mean annual rainfall and temperature of 1100 mm and 15°C, respectively. The soil is a relatively deep ( 80cm) sandy loam Cambisol, with gentle slopes (3°). The experimental design included three treatments: (i) control, without biochar; (ii) high biochar application rate (40 ton/ha); and (iii) biochar compost (40 ton/ha, 10% biochar). Three plots per treatment (2m×3m) were installed in March 2012, using a mini-rotavator (0-15cm depth). In May 2016, soil quality was also assessed through soil surveys and sampling. Penetration resistance was performed at the soil surface with a pocket penetrometer, and soil surface sampling rings were used for bulk density analyses (100 cm3). Bulked soil samples (0-30 cm) were collected in each plot for aggregate stability, microbial biomass (by chloroform fumigation extraction) and net mineralization rate (through photometric determination of non-incubated and incubated samples). Decomposition rate and litter stabilisation was assessed over a 3-month period through the Tea Bag Index (Keuskamp et al., 2013). The number, type and biomass of earthworms was recorded in each plot, at the soil surface (through excavation, 30cm×30cm×30cm) and sub-surface (using a mustard-tap water solution in the excavated hole). Crop yield was evaluated during harvesting (August 2016), through the number and weight of grape clusters. The potential impact of biochar on grape quality was investigated by total acidity, pH, potential alcoholic strength and total sugar in must analyses. Four years after the application, plots with high biochar showed lowest soil resistance, slightly lower bulk density, higher crop yield and must quality, than control plots. However, the soil of biochar plots also displayed slightly lower aggregate stability, microbial biomass, number and biodiversity of earthworms, although higher net-N mineralization, decomposition rate and litter stabilization. Plots with biochar and compost showed lowest earthworms, decomposition rate and litter stabilization, but highest crop yield that the other two treatments. Nevertheless, minor differences between three treatment plots suggest that potential impacts of biochar on soil quality and crop yield may persist during a relatively short period.

Biochar increases plant available water in a sandy soil under an aerobic rice cropping system

NASA Astrophysics Data System (ADS)

de Melo Carvalho, M. T.; de Holanda Nunes Maia, A.; Madari, B. E.; Bastiaans, L.; van Oort, P. A. J.; Heinemann, A. B.; Soler da Silva, M. A.; Petter, F. A.; Meinke, H.

2014-03-01

The main objective of this study was to assess the impact of biochar rate (0, 8, 16 and 32 t ha-1) on the water retention capacity (WRC) of a sandy Dystric Plinthosol. The applied biochar was a by-product of slow pyrolysis (∼450 °C) of eucalyptus wood, milled to pass through a 2000 μm sieve that resulted in a material with an intrinsic porosity ≤10 μm and a specific surface area of ∼3.2 m2 g-1. The biochar was incorporated into the top 15 cm of the soil under an aerobic rice system. Our study focused on both the effects on WRC and rice yields at 2 and 3 years after application. Undisturbed soil samples were collected from 16 plots in two soil layers (5-10 and 15-20 cm). Soil water retention curves were modelled using a nonlinear mixed model which appropriately accounts for uncertainties inherent of spatial variability and repeated measurements taken within a specific soil sample. We found an increase in plant available water in the upper soil layer proportional to the rate of biochar, with about 0.8% for each t ha-1 of biochar amendment at 2 and 3 years after application. The impact of biochar on soil WRC was most likely related to an increase in overall porosity of the sandy soil, which was evident from an increase in saturated soil moisture and macro porosity with 0.5% and 1.6% for each t ha-1 of biochar applied, respectively. The increment in soil WRC did not translate into an increase in rice yield, essentially because in both seasons the amount of rainfall during critical period for rice production exceeded 650 mm. The use of biochar as a soil amendment can be a worthy strategy to guarantee yield stability under water limited conditions. Our findings raise the importance of assessing the feasibility of very high application rates of biochar and the inclusion of a detailed analysis of its physical and chemical properties as part of future investigations.

Biochar increases plant-available water in a sandy loam soil under an aerobic rice crop system

NASA Astrophysics Data System (ADS)

de Melo Carvalho, M. T.; de Holanda Nunes Maia, A.; Madari, B. E.; Bastiaans, L.; van Oort, P. A. J.; Heinemann, A. B.; Soler da Silva, M. A.; Petter, F. A.; Marimon, B. H., Jr.; Meinke, H.

2014-09-01

The main objective of this study was to assess the impact of biochar rate (0, 8, 16 and 32 Mg ha-1) on the water retention capacity (WRC) of a sandy loam Dystric Plinthosol. The applied biochar was a by-product of slow pyrolysis (∼450 °C) of eucalyptus wood, milled to pass through a 2000 μm sieve that resulted in a material with an intrinsic porosity ≤10 μm and a specific surface area of ∼3.2 m2 g-1. The biochar was incorporated into the top 15 cm of the soil under an aerobic rice system. Our study focused on both the effects on WRC and rice yields 2 and 3 years after its application. Undisturbed soil samples were collected from 16 plots in two soil layers (5-10 and 15-20 cm). Soil water retention curves were modelled using a nonlinear mixed model which appropriately accounts for uncertainties inherent of spatial variability and repeated measurements taken within a specific soil sample. We found an increase in plant-available water in the upper soil layer proportional to the rate of biochar, with about 0.8% for each Mg ha-1 biochar amendment 2 and 3 years after its application. The impact of biochar on soil WRC was most likely related to an effect in overall porosity of the sandy loam soil, which was evident from an increase in saturated soil moisture and macro porosity with 0.5 and 1.6% for each Mg ha-1 of biochar applied, respectively. The increment in soil WRC did not translate into an increase in rice yield, essentially because in both seasons the amount of rainfall during the critical period for rice production exceeded 650 mm. The use of biochar as a soil amendment can be a worthy strategy to guarantee yield stability under short-term water-limited conditions. Our findings raise the importance of assessing the feasibility of very high application rates of biochar and the inclusion of a detailed analysis of its physical and chemical properties as part of future investigations.

Molecular characterization of biochars and their influence on microbiological properties of soil.

PubMed

Chintala, Rajesh; Schumacher, Thomas E; Kumar, Sandeep; Malo, Douglas D; Rice, James A; Bleakley, Bruce; Chilom, Gabriela; Clay, David E; Julson, James L; Papiernik, Sharon K; Gu, Zheng Rong

2014-08-30

The tentative connection between the biochar surface chemical properties and their influence on microbially mediated mineralization of C, N, and S with the help of enzymes is not well established. This study was designed to investigate the effect of different biomass conversion processes (microwave pyrolysis, carbon optimized gasification, and fast pyrolysis using electricity) on the composition and surface chemistry of biochar materials produced from corn stover (Zea mays L.), switchgrass (Panicum virgatum L.), and Ponderosa pine wood residue (Pinus ponderosa Lawson and C. Lawson) and determine the effect of biochars on mineralization of C, N, and S and associated soil enzymatic activities including esterase (fluorescein diacetate hydrolase, FDA), dehydrogenase (DHA), β-glucosidase (GLU), protease (PROT), and aryl sulfatase (ARSUL) in two different soils collected from footslope (Brookings) and crest (Maddock) positions of a landscape. Chemical properties of biochar materials produced from different batches of gasification process were fairly consistent. Biochar materials were found to be highly hydrophobic (low H/C values) with high aromaticity, irrespective of biomass feedstock and pyrolytic process. The short term incubation study showed that biochar had negative effects on microbial activity (FDA and DHA) and some enzymes including β-glucosidase and protease. Published by Elsevier B.V.

Cadmium, lead, and zinc mobility and plant uptake in a mine soil amended with sugarcane straw biochar.

PubMed

Puga, A P; Abreu, C A; Melo, L C A; Paz-Ferreiro, J; Beesley, L

2015-11-01

Accumulation of heavy metals in unconsolidated soils can prove toxic to proximal environments, if measures are not taken to stabilize soils. One way to minimize the toxicity of metals in soils is the use of materials capable of immobilizing these contaminants by sorption. Biochar (BC) can retain large amounts of heavy metals due to, among other characteristics, its large surface area. In the current experiment, sugarcane-straw-derived biochar, produced at 700 °C, was applied to a heavy-metal-contaminated mine soil at 1.5, 3.0, and 5.0% (w/w). Jack bean and Mucuna aterrima were grown in pots containing a mine contaminated soil and soil mixed with BC. Pore water was sampled to assess the effects of biochar on zinc solubility, while soils were analyzed by DTPA extraction to confirm available metal concentrations. The application of BC decreased the available concentrations of Cd, Pb, and Zn in the mine contaminated soil leading to a consistent reduction in the concentration of Zn in the pore water. Amendment with BC reduced plant uptake of Cd, Pb, and Zn with the jack bean uptaking higher amounts of Cd and Pb than M. aterrima. This study indicates that biochar application during mine soil remediation could reduce plant concentrations of heavy metals. Coupled with this, symptoms of heavy metal toxicity were absent only in plants growing in pots amended with biochar. The reduction in metal bioavailability and other modifications to the substrate induced by the application of biochar may be beneficial to the establishment of a green cover on top of mine soil to aid remediation and reduce risks.

[Effect of biochar addition on soil evaporation.

PubMed

Xu, Jian; Niu, Wen Quan; Zhang, Ming Zhi; Li, Yuan; Lyu, Wang; Li, Kang-Yong; Zou, Xiao-Yang; Liang, Bo-Hui

2016-11-18

In order to determine the rational amount of biochar application and its effect on soil hydrological processes in arid area, soil column experiments were conducted in the laboratory using three biochar additions (5%, 10% and 15%) and four different biochar types (d<0.25 mm bamboo charcoal, 0.25 mm

Porous media augmented with biochar for the retention of E. coli

NASA Astrophysics Data System (ADS)

Kolotouros, Christos A.; Manariotis, Ioannis D.; Karapanagioti, Hrissi K.

2016-04-01

A significant number of epidemic outbreaks has been attributed to waterborne fecal-borne pathogenic microorganisms from contaminated ground water. The transport of pathogenic microorganisms in groundwater is controlled by physical and chemical soil properties like soil structure, texture, percent water saturation, soil ionic strength, pore-size distribution, soil and solution pH, soil surface charge, and concentration of organic carbon in solution. Biochar can increase soil productivity by improving both chemical and physical soil properties. The mixing of biochar into soils may stimulate microbial population and activate dormant soil microorganisms. Furthermore, the application of biochar into soil affects the mobility of microorganisms by altering the physical and chemical properties of the soil, and by retaining the microorganisms on the biochar surface. The aim of this study was to investigate the effect of biochar mixing into soil on the transport of Escherichia coli in saturated porous media. Initially, batch experiments were conducted at two different ionic strengths (1 and 150 mM KCl) and at varying E. coli concentrations in order to evaluate the retention of E. coli on biochar in aqueous solutions. Kinetic analysis was conducted, and three isotherm models were employed to analyze the experimental data. Column experiments were also conducted in saturated sand columns augmented with different biochar contents, in order to examine the effect of biochar on the retention of E. coli. The Langmuir model fitted better the retention experimental data, compared to Freundlich and Tempkin models. The retention of E. coli was enhanced at lower ionic strength. Finally, biochar-augmented sand columns were more capable in retaining E. coli than pure sand columns.

Sorption of Lincomycin by Manure-Derived Biochars from Water

PubMed Central

Liu, Cheng-Hua; Chuang, Ya-Hui; Li, Hui; Teppen, Brian J.; Boyd, Stephen A.; Gonzalez, Javier M.; Johnston, Cliff T.; Lehmann, Johannes; Zhang, Wei

2018-01-01

The presence of antibiotics in agroecosystems raises concerns about the proliferation of antibiotic-resistant bacteria and adverse effects to human health. Soil amendment with biochars pyrolized from manures may be a win-win strategy for novel manure management and antibiotics abatement. In this study, lincomycin sorption by manure-derived biochars was examined using batch sorption experiments. Lincomycin sorption was characterized by two-stage kinetics with fast sorption reaching quasi-equilibrium in the first 2 d, followed by slow sorption over 180 d. The fast sorption was primarily attributed to surface adsorption, whereas the long-term slow sorption was controlled by slow diffusion of lincomycin into biochar pore structures. Two-day sorption experiments were performed to explore effects of biochar particle size, solid/water ratio, solution pH, and ionic strength. Lincomycin sorption to biochars was greater at solution pH 6.0 to 7.5 below the dissociation constant of lincomycin (7.6) than at pH 9.9 to 10.4 above its dissociation constant. The enhanced lincomycin sorption at lower pH likely resulted from electrostatic attraction between the positively charged lincomycin and the negatively charged biochar surfaces. This was corroborated by the observation that lincomycin sorption decreased with increasing ionic strength at lower pH (6.7) but remained constant at higher pH (10). The long-term lincomycin sequestration by biochars was largely due to pore diffusion plausibly independent of solution pH and ionic composition. Therefore, manure-derived biochars had lasting lincomycin sequestration capacity, implying that biochar soil amendment could significantly affect the distribution, transport, and bioavailability of lincomycin in agroecosystems. PMID:27065399

Effects of pressure on morphology and structure of bio-char from pressurized entrained-flow pyrolysis of microalgae.

PubMed

Maliutina, Kristina; Tahmasebi, Arash; Yu, Jianglong

2018-06-01

The present dataset describes the entrained-flow pyrolysis of Microalgae Chlorella vulgaris and the results obtained during bio-char characterization. The dataset includes a brief explanation of the experimental procedure, experimental conditions and the influence of pyrolysis conditions on bio-chars morphology and carbon structure. The data show an increase in sphericity and surface smoothness of bio-chars at higher pressures and temperatures. Data confirmed that the swelling ratio of bio-chars increased with pressure up to 2.0 MPa. Consequently, changes in carbon structure of bio-chars were investigated using Raman spectroscopy. The data showed the increase in carbon order of chars at elevated pressures. Changes in the chemical structure of bio-char as a function of pyrolysis conditions were investigated using FTIR analysis.

Sorption of norfloxacin, sulfamerazine and oxytetracycline by KOH-modified biochar under single and ternary systems.

PubMed

Luo, Jiwei; Li, Xue; Ge, Chengjun; Müller, Karin; Yu, Huamei; Huang, Peng; Li, Jiatong; Tsang, Daniel C W; Bolan, Nanthi S; Rinklebe, Jörg; Wang, Hailong

2018-05-08

Pollution of water by single antibiotics has been investigated in depth. However, in reality, a wide range of different contaminants is often mixed in the aquatic environment (contaminant cocktail). Here, single and competitive sorption dynamics of ionizable norfloxacin (NOR), sulfamerazine (SMR) and oxytetracycline (OTC) by both pristine and modified biochars were investigated. Sorption kinetics of the three antibiotics was faster in ternary-solute than single-solute system. Sorption efficiency was enhanced in the competitive system for NOR by the pristine biochar, and for OTC by both the pristine biochar and the modified biochar, while SMR sorption by the pristine biochar and the KOH-modified biochar was inhibited. Sorption was governed by electrostatic interactions, π-π EDA and H-bonds for antibiotics sorption by biochar. SMR and OTC sorption by biochar was influenced by cation bridging and surface complexation, respectively. This research finding will guide the development of treatment procedures for water polluted by multiple antibiotics. Copyright © 2018 Elsevier Ltd. All rights reserved.

Biochar-based nano-composites for the decontamination of wastewater: A review.

PubMed

Tan, Xiao-Fei; Liu, Yun-Guo; Gu, Yan-Ling; Xu, Yan; Zeng, Guang-Ming; Hu, Xin-Jiang; Liu, Shao-Bo; Wang, Xin; Liu, Si-Mian; Li, Jiang

2016-07-01

Synthesizing biochar-based nano-composites can obtain new composites and combine the advantages of biochar with nano-materials. The resulting composites usually exhibit great improvement in functional groups, pore properties, surface active sites, catalytic degradation ability and easy to separation. These composites have excellent abilities to adsorb a range of contaminants from aqueous solutions. Particularly, catalytic material-coated biochar can exert simultaneous adsorption and catalytic degradation function for organic contaminants removal. Synthesizing biochar-based nano-composites has become an important practice for expanding the environmental applications of biochar and nanotechnology. This paper aims to review and summarize the various synthesis techniques for biochar-based nano-composites and their effects on the decontamination of wastewater. The characteristic and advantages of existing synthesis methods are summarized and discussed. Application of biochar-based nano-composites for different contaminants removal and the underlying mechanisms are reviewed. Furthermore, knowledge gaps that exist in the fabrication and application of biochar-based nano-composites are also identified. Copyright © 2016 Elsevier Ltd. All rights reserved.

Endogenous minerals have influences on surface electrochemistry and ion exchange properties of biochar.

PubMed

Zhao, Ling; Cao, Xinde; Zheng, Wei; Wang, Qun; Yang, Fan

2015-10-01

The feedstocks for biochar production are diverse and many of them contain various minerals in addition to being rich in carbon. Twelve types of biomass classified into 2 categories: plant-based and municipal waste, were employed to produce biochars under 350 °C and 500 °C. Their pH, point of zero net charge (PZNC), zeta potential, cation and anion exchange capacity (CEC and AEC) were analyzed. The municipal waste-based biochars (MW-BC) had higher mineral levels than the plant-based biochars (PB-BC). However, the water soluble mineral levels were lower in the MW-BCs due to the dominant presence of less soluble minerals, such as CaCO3 and (Ca,Mg)3(PO4)2. The higher total minerals in MW-BCs accounted for the higher PZNC (5.47-9.95) than in PB-BCs (1.91-8.18), though the PZNCs of the PB-BCs increased more than that of the MW-BCs as the production temperature rose. The minerals had influence on the zeta potentials via affecting the negative charges of biochars and the ionic strength of solution. The organic functional groups in PB-BCs such as -COOH and -OH had a greater effect on the CEC and AEC, while the minerals had a greater effect on that of MW-BCs. The measured CEC and AEC values had a strong positive correlation with the total amount of soluble cations and anions, respectively. Results indicated that biochar surface charges depend not only on the organic functional groups, but also on the minerals present and to some extent, minerals have more influences on the surface electrochemistry and ion exchange properties of biochar. Copyright © 2015 Elsevier Ltd. All rights reserved.

Watershed soil Cd loss after long-term agricultural practice and biochar amendment under four rainfall levels.

PubMed

Ouyang, Wei; Huang, Weijia; Hao, Xin; Tysklind, Mats; Haglund, Peter; Hao, Fanghua

2017-10-01

Some heavy metals in farmland soil can be transported into the waterbody, affecting the water quality and sediment at the watershed outlet, which can be used to determine the historical loss pattern. Cd is a typical heavy metal leached from farmland that is related to phosphate fertilizers and carries serious environmental risk. The spatial-vertical pattern of Cd in soil and the vertical trend of Cd in the river sediment core were analyzed, which showed the migration and accumulation of Cd in the watershed. To prevent watershed Cd loss, biochar was employed, and leaching experiments were conducted to investigate the Cd loss from soil depending on the initial concentration. Four rainfall intensities, 1.25 mm/h, 2.50 mm/h, 5.00 mm/h, and 10.00 mm/h, were used to simulate typical rainfall scenarios for the study area. Biochar was prepared from corn straw after pretreatment with ammonium dihydrogen phosphate (ADP) and pyrolysis at 400 °C under anoxic conditions. To identify the effects of biochar amendment on Cd migration, the biochar was mixed with soil for 90 days at concentrations of 0%, 0.5%, 1.0%, 3.0%, and 5.0% soil by weight. The results showed that the Cd leaching load increased as the initial load and rainfall intensity increased and that eluviation caused surface Cd to diffuse to the deep soils. The biochar application caused more of the heavy metals to be immobilized in the amended soil rather than transported into the waterbody. The sorption efficiency of the biochar for Cd increased as the addition level increased to 3%, which showed better performance than the 5% addition level under some initial concentration and rainfall conditions. The research indicated that biochar is a potential material to prevent diffuse heavy metal pollution and that a lower addition makes the application more feasible. Copyright © 2017 Elsevier Ltd. All rights reserved.

Lowering N2O emissions from soils using eucalypt biochar: the importance of redox reactions

PubMed Central

Quin, P; Joseph, S; Husson, O; Donne, S; Mitchell, D; Munroe, P; Phelan, D; Cowie, A; Van Zwieten, L

2015-01-01

Agricultural soils are the primary anthropogenic source of atmospheric nitrous oxide (N2O), contributing to global warming and depletion of stratospheric ozone. Biochar addition has shown potential to lower soil N2O emission, with the mechanisms remaining unclear. We incubated eucalypt biochar (550 °C) – 0, 1 and 5% (w/w) in Ferralsol at 3 water regimes (12, 39 and 54% WFPS) – in a soil column, following gamma irradiation. After N2O was injected at the base of the soil column, in the 0% biochar control 100% of expected injected N2O was released into headspace, declining to 67% in the 5% amendment. In a 100% biochar column at 6% WFPS, only 16% of the expected N2O was observed. X-ray photoelectron spectroscopy identified changes in surface functional groups suggesting interactions between N2O and the biochar surfaces. We have shown increases in -O-C = N /pyridine pyrrole/NH3, suggesting reactions between N2O and the carbon (C) matrix upon exposure to N2O. With increasing rates of biochar application, higher pH adjusted redox potentials were observed at the lower water contents. Evidence suggests that biochar has taken part in redox reactions reducing N2O to dinitrogen (N2), in addition to adsorption of N2O. PMID:26615820

Adsorption kinetics of magnetic biochar derived from peanut hull on removal of Cr (VI) from aqueous solution: Effects of production conditions and particle size.

PubMed

Han, Yitong; Cao, Xi; Ouyang, Xin; Sohi, Saran P; Chen, Jiawei

2016-02-01

Magnetic biochar was made from peanut hull biomass using iron chloride in a simplified aqueous phase approach and pyrolysis at alternative peak temperatures (450-650 °C). Magnetic biochar showed an extreme capacity for adsorption of hexavalent chromium Cr (VI) from aqueous solution, which was 1-2 orders of magnitude higher compared to standard (non-magnetic) biochar from the same feedstock. Adsorption increased with pyrolysis temperature peaking at 77,542 mg kg(-1) in the sample pyrolysed at 650 °C. In contrast to magnetic biochar, the low adsorption capacity of standard biochar decreased with increasing pyrolysis temperature. The fine particle size of magnetic biochar and low aqueous pH were also important for adsorption. Surfaces of products from batch adsorption experiments were characterized by scanning electron microscopy, energy-dispersive X-ray analysis, X-ray diffraction, X-ray photoelectron spectroscopy and vibrating sample magnetometer. This revealed that γ-Fe2O3 was crucial to the properties (adsorbance and magnetism) of magnetic biochar. The removal mechanism was the Cr (VI) electrostatic attracted on protonated -OH on γ-Fe2O3 surface and it could be desorbed by alkaline solution. Findings suggest that pyrolysis has potential to create effective, magnetically recoverable adsorbents relevant to environmental application. Copyright © 2015 Elsevier Ltd. All rights reserved.

Comparative study on pharmaceuticals adsorption in reclaimed water desalination concentrate using biochar: Impact of salts and organic matter.

PubMed

Lin, Lu; Jiang, Wenbin; Xu, Pei

2017-12-01

The synergistic impact of salts and organic matter on adsorption of ibuprofen and sulfamethoxazole by three types of biochar and an activated carbon was investigated using reclaimed water reverse osmosis (RO) concentrate and synthetic solutions spiked with target organic compounds and non-target water constituents (e.g., Na + , Ca 2+ , Mg 2+ , K + , Cl - , SO 4 2- , alkalinity, humic acid (HA), and bovine serum albumin (BSA)). Kinetic modeling was used to better understand the adsorption process between the carbon adsorbents and pharmaceuticals and to elucidate the impact of water chemistry on pharmaceuticals adsorption. The adsorption capacity of pharmaceuticals by biochar was affected by their physicochemical properties including ash content, specific surface area, charge, pore volume, as well as hydrophobicity, π-energy, and speciation of pharmaceuticals. The adsorption of pharmaceuticals in concentrate was pH-dependent, the kinetic rate constant increased with deceasing pH due to the electrical interactions between pharmaceutical molecules and adsorbents. High salinity and electrolyte ions in RO concentrate improved adsorption, whereas the presence of carbonate species, HA, and BSA hindered the removal of ibuprofen and sulfamethoxazole. This study revealed the correlation of concentrate water quality on adsorption of pharmaceuticals by biochar and activated carbon. Biochar provides a promising alternative to activated carbon for removal of organic contaminants of emerging concerns in various wastewater and concentrate streams. Copyright © 2017 Elsevier B.V. All rights reserved.

Biochar as a Substitute for Peat in Greenhouse Growing Media: Soil Water Characteristics and Carbon Leaching Dynamics

NASA Astrophysics Data System (ADS)

Johnson, M. S.; Hilbert, I.; Jollymore, A. J.

2012-12-01

Biochar (charcoal derived from waste biomass via pyrolysis) has the potential to be used as part of regional scale carbon sequestration strategies. By providing a stable form of carbon that is resistant to decay in soils, biochar can be utilized in a wide range of applications to improve the sustainability of land use management practices. Due to its high water holding capacity, surface area and charge density, it could provide a substitute for peat that is widely used in horticultural activities. Globally, peat production in 2010 amounted to 23.4 Mt, with more than a third of this used for horticulture. In Canada, essentially all peat produced is used for horticulture, with each ton of peat extracted also contributing about 0.7 t CO2e in combined greenhouse gas emissions related to production, transportation and use of peat. We evaluated biochar produced on farm from red alder as a peat substitute in terms of soil water characteristics and carbon leaching in greenhouse growing media (e.g. potting mix). Biochar mixing ratios of 10% (v/v) and greater provided water holding capacity equivalent to peat-based potting mixes. We also present results from a laboratory wetting experiment in which we characterized leachate for dissolved organic carbon (DOC) concentration and DOC characteristics using spectral methods (uV-Vis and fluorescence spectroscopy).

Biochar-based carbons with hierarchical micro-meso-macro porosity for high rate and long cycle life supercapacitors

NASA Astrophysics Data System (ADS)

Qiu, Zhipeng; Wang, Yesheng; Bi, Xu; Zhou, Tong; Zhou, Jin; Zhao, Jinping; Miao, Zhichao; Yi, Weiming; Fu, Peng; Zhuo, Shuping

2018-02-01

The development of supercapacitors with high energy density and power density is an important research topic despite many challenging issues exist. In this work, porous carbon material was prepared from corn straw biochar and used as the active electrode material for electric double-layer capacitors (EDLCs). During the KOH activation process, the ratio of KOH/biochar significantly affects the microstructure of the resultant carbon, which further influences the capacitive performance. The optimized carbon material possesses typical hierarchical porosity composed of multi-leveled pores with high surface area and pore volume up to 2790.4 m2 g-1 and 2.04 cm3 g-1, respectively. Such hierarchical micro-meso-macro porosity significantly improved the rate performance of the biochar-based carbons. The achieved maximum specific capacitance was 327 F g-1 and maintained a high value of 205 F g-1 at a ultrahigh current density of 100 A g-1. Meanwhile, the prepared EDLCs present excellent cycle stability in alkaline electrolytes for 120 000 cycles at 5 A g-1. Moreover, the biochar-based carbon could work at a high voltage of 1.6 V in neutral Na2SO4, and exhibit a high specific capacitance of 227 F g-1, thus giving an outstanding energy density of 20.2 Wh kg-1.

Solubility of lead and copper in biochar-amended small arms range soils: influence of soil organic carbon and pH.

PubMed

Uchimiya, Minori; Bannon, Desmond I

2013-08-14

Biochar is often considered a strong heavy metal stabilizing agent. However, biochar in some cases had no effects on, or increased the soluble concentrations of, heavy metals in soil. The objective of this study was to determine the factors causing some biochars to stabilize and others to dissolve heavy metals in soil. Seven small arms range soils with known total organic carbon (TOC), cation exchange capacity, pH, and total Pb and Cu contents were first screened for soluble Pb and Cu concentrations. Over 2 weeks successive equilibrations using weak acid (pH 4.5 sulfuric acid) and acetate buffer (0.1 M at pH 4.9), Alaska soil containing disproportionately high (31.6%) TOC had nearly 100% residual (insoluble) Pb and Cu. This soil was then compared with sandy soils from Maryland containing significantly lower (0.5-2.0%) TOC in the presence of 10 wt % (i) plant biochar activated to increase the surface-bound carboxyl and phosphate ligands (PS450A), (ii) manure biochar enriched with soluble P (BL700), and (iii) unactivated plant biochars produced at 350 °C (CH350) and 700 °C (CH500) and by flash carbonization (corn). In weak acid, the pH was set by soil and biochar, and the biochars increasingly stabilized Pb with repeated extractions. In pH 4.9 acetate buffer, PS450A and BL700 stabilized Pb, and only PS450A stabilized Cu. Surface ligands of PS450A likely complexed and stabilized Pb and Cu even under acidic pH in the presence of competing acetate ligand. Oppositely, unactivated plant biochars (CH350, CH500, and corn) mobilized Pb and Cu in sandy soils; the putative mechanism is the formation of soluble complexes with biochar-borne dissolved organic carbon. In summary, unactivated plant biochars can inadvertently increase dissolved Pb and Cu concentrations of sandy, low TOC soils when used to stabilize other contaminants.

Engineered/designer biochar for contaminant removal/immobilization from soil and water: Potential and implication of biochar modification.

PubMed

Rajapaksha, Anushka Upamali; Chen, Season S; Tsang, Daniel C W; Zhang, Ming; Vithanage, Meththika; Mandal, Sanchita; Gao, Bin; Bolan, Nanthi S; Ok, Yong Sik

2016-04-01

The use of biochar has been suggested as a means of remediating contaminated soil and water. The practical applications of conventional biochar for contaminant immobilization and removal however need further improvements. Hence, recent attention has focused on modification of biochar with novel structures and surface properties in order to improve its remediation efficacy and environmental benefits. Engineered/designer biochars are commonly used terms to indicate application-oriented, outcome-based biochar modification or synthesis. In recent years, biochar modifications involving various methods such as, acid treatment, base treatment, amination, surfactant modification, impregnation of mineral sorbents, steam activation and magnetic modification have been widely studied. This review summarizes and evaluates biochar modification methods, corresponding mechanisms, and their benefits for contaminant management in soil and water. Applicability and performance of modification methods depend on the type of contaminants (i.e., inorganic/organic, anionic/cationic, hydrophilic/hydrophobic, polar/non-polar), environmental conditions, remediation goals, and land use purpose. In general, modification to produce engineered/designer biochar is likely to enhance the sorption capacity of biochar and its potential applications for environmental remediation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Thorium binding by biochar fibres derived from Luffa Cylindrica after controlled surface oxidation

NASA Astrophysics Data System (ADS)

Liatsou, Ioanna; Christodoulou, Eleni; Paschalidis, Ioannis

2017-04-01

Controlled surface modification of biochar fibres derived from Luffa Cylindrica sponges has been carried out by nitric acid and the degree of oxidation could be controlled by changing the acid concentration or the reaction time. The extent of surface oxidation has been quantified by acid-base titration and FTIR-spectroscopy. Furthermore, thorium binding has been studied as a function of various parameters and the experimental results show that even under strong acidic conditions the relative sorption is above 70% and the sorption capacity of the biochar fibres for Th(IV) at pH 3 is qmax= 70 gṡkg-1.

Highly efficient adsorption of dyes by biochar derived from pigments-extracted macroalgae pyrolyzed at different temperature.

PubMed

Chen, Yi-di; Lin, Yen-Chang; Ho, Shih-Hsin; Zhou, Yan; Ren, Nan-Qi

2018-07-01

Biochar is known to efficiently adsorb dyes from wastewater. In this study, biochar was derived from macroalgae residue by pyrolysis, and the influence of varying temperature (from 400 °C to 800 °C) on biochar characteristics was investigated. Among the biochar samples tested, macroalgae-derived biochar possessing highly porous structure, special surface chemical behavior and high thermal stability was found to be efficient in removing malachite green, crystal violet and Congo red. The biochar derived by pyrolysis at 800 °C showed the highest adsorption capacity for malachite green (5306.2 mg g -1 ). In this study, the transformation of microalgae residue into a highly efficient dye adsorbent is a promising procedure for economic and environmental protection. Copyright © 2018 Elsevier Ltd. All rights reserved.

Magnesium Oxide Embedded Nitrogen Self-Doped Biochar Composites: Fast and High-Efficiency Adsorption of Heavy Metals in an Aqueous Solution.

PubMed

Ling, Li-Li; Liu, Wu-Jun; Zhang, Shun; Jiang, Hong

2017-09-05

Lead (Pb) pollution in natural water bodies is an environmental concern due to toxic effects on aquatic ecosystems and human health, while adsorption is an effective approach to remove Pb from the water. Surface interactions between adsorbents and adsorbates play a dominant role in the adsorption process, and properly engineering a material's surface property is critical to the improvement of adsorption performance. In this study, the magnesium oxide (MgO) nanoparticles stabilized on the N-doped biochar (MgO@N-biochar) were synthesized by one-pot fast pyrolysis of an MgCl 2 -loaded N-enriched hydrophyte biomass as a way to increase the exchangeable ions and N-containing functional groups and facilitate the adsorption of Pb 2+ . The as-synthesized MgO@N-biochar has a high performance with Pb in an aqueous solution with a large adsorption capacity (893 mg/g), a very short equilibrium time (<10 min), and a large throughput (∼4450 BV). Results show that this excellent adsorption performance can be maintained with various environmentally relevant interferences including pH, natural organic matter, and other metal ions, suggesting that the material may be suitable for the treatment of wastewater, natural bodies of water, and even drinking water. In addition, MgO@N-biochar quickly and efficiently removed Cd 2+ and tetracycline. Multiple characterizations and comparative tests have been performed to demonstrate the surface adsorption and ion exchange contributed to partial Pb adsorption, and it can be inferred from these results that the high performance of MgO@N-biochar is mainly due to the surface coordination of Pb 2+ and C═O or O═C-O, pyridinic, pyridonic, and pyrrolic N. This work suggests that engineering surface functional groups of biochar may be crucial for the development of high performance heavy metal adsorbents.

Storage and stability of biochar-derived carbon and total organic carbon in relation to minerals in an acid forest soil of the Spanish Atlantic area.

PubMed

Fernández-Ugalde, Oihane; Gartzia-Bengoetxea, Nahia; Arostegi, Javier; Moragues, Lur; Arias-González, Ander

2017-06-01

Biochar can largely contribute to enhance organic carbon (OC) stocks in soil and improve soil quality in forest and agricultural lands. Its contribution depends on its recalcitrance, but also on its interactions with minerals and other organic compounds in soil. Thus, it is important to study the link between minerals, natural organic matter and biochar in soil. In this study, we investigated the incorporation of biochar-derived carbon (biochar-C) into various particle-size fractions with contrasting mineralogy and the effect of biochar on the storage of total OC in the particle-size fractions in an acid loamy soil under Pinus radiata (C3 type) in the Spanish Atlantic area. We compared plots amended with biochar produced from Miscanthus sp. (C4 type) with control plots (not amended). We separated sand-, silt-, and clay-size fractions in samples collected from 0 to 20-cm depth. In each fraction, we analyzed clay minerals, metallic oxides and oxy-hydroxides, total OC and biochar-C. The results showed that 51% of the biochar-C was in fractions <20μm one year after the application of biochar. Biochar-C stored in clay-size fractions (0.2-2μm, 0.05-0.2μm, <0.05μm) was only 14%. Even so, we observed that biochar-C increased with decreasing particle-size in clay-size fractions, as it occurred with the vermiculitic phases and metallic oxides and oxy-hydroxides. Biochar also affected to the distribution of total OC among particle-size fractions. Total OC concentration was greater in fractions 2-20μm, 0.2-2μm, 0.05-0.2μm in biochar-amended plots than in control plots. This may be explained by the adsorption of dissolved OC from fraction <0.05μm onto biochar particles. The results suggested that interactions between biochar, minerals and pre-existing organic matter already occurred in the first year. Copyright © 2017 Elsevier B.V. All rights reserved.

Magnetic adsorbents for the removal of Hg (II) and phenanthrene from aqueous solutions

NASA Astrophysics Data System (ADS)

Isari, Ekavi; Karapanagioti, Hrissi K.; Manariotis, Ioannis D.; Werner, David

2015-04-01

Activated carbon (AC) acts as a strong binding agent that lowers the pollutant concentration and, thus its toxicity. Another promising sorbent material in environmental applications is biochar (BC) which is obtained from the incomplete combustion of carbon-rich biomass under oxygen-limited conditions. Both of these materials could be used as soil or sediment amendments that would lower the toxicity in the aqueous phase. A draw back of this technique is that although the pollutant will remain non- bioavailable for many years being sorbed into these sorbents, it actually stays into the system. The objective of this study was (a) to synthesize a magnetic powdered activated carbon (AC/Fe) and magnetic powdered biochar (BC/Fe) produced from commercial AC1 and AC2 samples and biochar respectively and (b) to evaluate the potential use of AC/Fe and BIO/Fe to remove aqueous Hg (II) or phenanthrene while being magnetically recoverable. The BC was produced from olive pomace. The surface area, the pore volume, and the average pore size of each sorbent were determined using gas (N2) adsorption-desorption cycles and the Brunauer, Emmett, and Teller (BET) equation. Isotherms with 30 adsorption and 20 desorption points were conducted at liquid nitrogen temperature (77K). Open surface area and micropore volume were determined using t-plot method and Harkins & Jura equation. For both AC/Fe, surface area measurements resulted in 66% those of corresponding AC. For BC/Fe, the surface area was 82% that of BC. Batch experiments with all sorbent samples and mercury solutions were conducted at room temperature (25oC) and at pH 5 in order to compare the sorption properties of the materials. Similar tests were performed with phenanthrene solutions. Based on mercury isotherm data, AC/Fe and BC/Fe are effective sorbents but with lower sorption capacity compared to the initial materials (50-75% lower). All these properties point to promising materials that can effectively be used for in-situ environmental remediation and also be recovered.

Field experiment with liquid manure and enhanced biochar

NASA Astrophysics Data System (ADS)

Dunst, Gerald

2017-04-01

Field experiments with low amounts of various liquid manure enhanced biochars. In 2016 a new machine was developed to inject liquid biochar based fertilizer directly into the crop root zone. A large-scale field experiment with corn and oil seed pumpkin was set-up on 42 hectares on 15 different fields in the south East of Austria. Three treatments were compared: (1) surface spreading of liquid manure as control (common practice), (2) 20 cm deep root zone injection with same amount of liquid manure, and (3) 20 cm deep root zone injection with same amount of liquid manure mixed with 1 to 2 tons of various nutrient enhanced biochars. The biochar were quenched with the liquid phase from a separated digestate from a biogas plant (feedstock: cow manure). From May to October nitrate and ammonium content was analyzed monthly from 0-30cm and 30-60cm soil horizons. At the end of the growing season the yield was determined. The root zone injection of the liquid manure reduced the nitrate content during the first two months at 13-16% compared to the control. When the liquid manure was blended with biochar, Nitrate soil content was lowest (reduction 40-47%). On average the root zone injection of manure-biochar increased the yield by 7% compared to the surface applied control and 3% compared to the root zone injected manure without biochar. The results shows, that biochar is able to reduce the Nitrate load in soils and increase the yield of corn at the same time. The nutrient efficiency of organic liquid fertilizers can be increased.

Microstructural and associated chemical changes during the composting of a high temperature biochar: Mechanisms for nitrate, phosphate and other nutrient retention and release

USDA-ARS?s Scientific Manuscript database

Recent studies have demonstrated the importance of the nutrient status of biochar and soils prior to its inclusion in particular agricultural systems. Pre-treatment of nutrient-reactive biochar, where nutrients are loaded into pores and onto surfaces, gives improved yield outcomes compared to untrea...

Stabilization of nanoscale zero-valent iron (nZVI) with modified biochar for Cr(VI) removal from aqueous solution.

PubMed

Dong, Haoran; Deng, Junmin; Xie, Yankai; Zhang, Cong; Jiang, Zhao; Cheng, Yujun; Hou, Kunjie; Zeng, Guangming

2017-06-15

Three types of modified biochar (BC) were produced respectively with acid (HCl) treatment (HCl-BC), base (KOH) treatment (KOH-BC) and oxidation (H 2 O 2 ) treatment (H 2 O 2 -BC) of raw biochar. Both the raw biochar and modified biochars supported zero valent iron nanopartilces (nZVI) (i.e. nZVI@BC, nZVI@HCl-BC, nZVI@KOH-BC and nZVI@H 2 O 2 -BC) were synthesized and their capacities for Cr(VI) removal were compared. The results showed that the nZVI@HCl-BC exhibited the best performance and the underlying mechanisms were discussed. The surface elemental distribution maps of the nZVI@HCl-BC after reaction with Cr(VI) showed that Fe, Cr and O elements were deposited on the surface of HCl-BC evenly, indicating that the formed Cr(III)/Fe(III) could settle on the surface of HCl-BC uniformly rather than coated only on the nZVI surface. This reveals that the supporter HCl-BC could also play a role in alleviating the passivation of nZVI. Besides, the effects of mass ratio (nZVI/HCl-BC), pH, and initial Cr(VI) concentration on Cr(VI) removal were examined. At lower mass of HCl-BC, nZVI aggregation cannot be fully inhibited on the surface of HCl-BC, whereas excessive biochar can block the active sites of nZVI. Additionally, it was found that Cr(VI) removal by nZVI@HCl-BC was dependent on both pH and initial Cr(VI) concentration. Copyright © 2017 Elsevier B.V. All rights reserved.

Mechanisms of antimony adsorption onto soybean stover-derived biochar in aqueous solutions.

PubMed

Vithanage, Meththika; Rajapaksha, Anushka Upamali; Ahmad, Mahtab; Uchimiya, Minori; Dou, Xiaomin; Alessi, Daniel S; Ok, Yong Sik

2015-03-15

Limited mechanistic knowledge is available on the interaction of biochar with trace elements (Sb and As) that exist predominantly as oxoanions. Soybean stover biochars were produced at 300 °C (SBC300) and 700 °C (SBC700), and characterized by BET, Boehm titration, FT-IR, NMR and Raman spectroscopy. Bound protons were quantified by potentiometric titration, and two acidic sites were used to model biochar by the surface complexation modeling based on Boehm titration and NMR observations. The zero point of charge was observed at pH 7.20 and 7.75 for SBC300 and SBC700, respectively. Neither antimonate (Sb(V)) nor antimonite (Sb(III)) showed ionic strength dependency (0.1, 0.01 and 0.001 M NaNO3), indicating inner sphere complexation. Greater adsorption of Sb(III) and Sb(V) was observed for SBC300 having higher -OH content than SBC700. Sb(III) removal (85%) was greater than Sb(V) removal (68%). Maximum adsorption density for Sb(III) was calculated as 1.88 × 10(-6) mol m(-2). The Triple Layer Model (TLM) successfully described surface complexation of Sb onto soybean stover-derived biochar at pH 4-9, and suggested the formation of monodentate mononuclear and binuclear complexes. Spectroscopic investigations by Raman, FT-IR and XPS further confirmed strong chemisorptive binding of Sb to biochar surfaces. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of freeze-thaw cycling on grain size of biochar.

PubMed

Liu, Zuolin; Dugan, Brandon; Masiello, Caroline A; Wahab, Leila M; Gonnermann, Helge M; Nittrouer, Jeffrey A

2018-01-01

Biochar may improve soil hydrology by altering soil porosity, density, hydraulic conductivity, and water-holding capacity. These properties are associated with the grain size distributions of both soil and biochar, and therefore may change as biochar weathers. Here we report how freeze-thaw (F-T) cycling impacts the grain size of pine, mesquite, miscanthus, and sewage waste biochars under two drainage conditions: undrained (all biochars) and a gravity-drained experiment (mesquite biochar only). In the undrained experiment plant biochars showed a decrease in median grain size and a change in grain-size distribution consistent with the flaking off of thin layers from the biochar surface. Biochar grain size distribution changed from unimodal to bimodal, with lower peaks and wider distributions. For plant biochars the median grain size decreased by up to 45.8% and the grain aspect ratio increased by up to 22.4% after 20 F-T cycles. F-T cycling did not change the grain size or aspect ratio of sewage waste biochar. We also observed changes in the skeletal density of biochars (maximum increase of 1.3%), envelope density (maximum decrease of 12.2%), and intraporosity (porosity inside particles, maximum increase of 3.2%). In the drained experiment, mesquite biochar exhibited a decrease of median grain size (up to 4.2%) and no change of aspect ratio after 10 F-T cycles. We also document a positive relationship between grain size decrease and initial water content, suggesting that, biochar properties that increase water content, like high intraporosity and pore connectivity large intrapores, and hydrophilicity, combined with undrained conditions and frequent F-T cycles may increase biochar breakdown. The observed changes in biochar particle size and shape can be expected to alter hydrologic properties, and thus may impact both plant growth and the hydrologic cycle.

Effect of freeze-thaw cycling on grain size of biochar

PubMed Central

Dugan, Brandon; Masiello, Caroline A.; Wahab, Leila M.; Gonnermann, Helge M.; Nittrouer, Jeffrey A.

2018-01-01

Biochar may improve soil hydrology by altering soil porosity, density, hydraulic conductivity, and water-holding capacity. These properties are associated with the grain size distributions of both soil and biochar, and therefore may change as biochar weathers. Here we report how freeze-thaw (F-T) cycling impacts the grain size of pine, mesquite, miscanthus, and sewage waste biochars under two drainage conditions: undrained (all biochars) and a gravity-drained experiment (mesquite biochar only). In the undrained experiment plant biochars showed a decrease in median grain size and a change in grain-size distribution consistent with the flaking off of thin layers from the biochar surface. Biochar grain size distribution changed from unimodal to bimodal, with lower peaks and wider distributions. For plant biochars the median grain size decreased by up to 45.8% and the grain aspect ratio increased by up to 22.4% after 20 F-T cycles. F-T cycling did not change the grain size or aspect ratio of sewage waste biochar. We also observed changes in the skeletal density of biochars (maximum increase of 1.3%), envelope density (maximum decrease of 12.2%), and intraporosity (porosity inside particles, maximum increase of 3.2%). In the drained experiment, mesquite biochar exhibited a decrease of median grain size (up to 4.2%) and no change of aspect ratio after 10 F-T cycles. We also document a positive relationship between grain size decrease and initial water content, suggesting that, biochar properties that increase water content, like high intraporosity and pore connectivity large intrapores, and hydrophilicity, combined with undrained conditions and frequent F-T cycles may increase biochar breakdown. The observed changes in biochar particle size and shape can be expected to alter hydrologic properties, and thus may impact both plant growth and the hydrologic cycle. PMID:29329343

Fundamental and molecular composition characteristics of biochars produced from sugarcane and rice crop residues and by-products.

PubMed

Jeong, Chang Yoon; Dodla, Syam K; Wang, Jim J

2016-01-01

Biochar conversion of sugarcane and rice harvest residues provides an alternative for managing these crop residues that are traditionally burned in open field. Sugarcane leaves, bagasse, rice straw and husk were converted to biochar at four pyrolysis temperatures (PTs) of 450 °C, 550 °C, 650 °C, and 750 °C and evaluated for various elemental, molecular and surface properties. The carbon content of biochars was highest for those produced at 650-750 °C. Biochars produced at 550 °C showed the characteristics of biochar that are commonly interpreted as being stable in soil, with low H/C and O/C ratios and pyrolysis fingerprints dominated by aromatic and polyaromatic hydrocarbons. At 550 °C, all biochars also exhibited maximum CEC values with sugarcane leaves biochar (SLB) > sugarcane bagasse biochar (SBB) > rice straw biochar (RSB) > rice husk biochar (RHB). The pore size distribution of biochars was dominated by pores of 20 nm and high PT increased both smaller and larger than 50 nm pores. Water holding capacity of biochars increased with PT but the magnitude of the increase was limited by feedstock types, likely related to the hydrophobicity of biochars as evident by molecular composition, besides pore volume properties of biochars. Py-GC/MS analysis revealed a clear destruction of lignin with decarboxylation and demethoxylation at 450 °C and dehydroxylation at above 550 °C. Overall, biochar molecular compositions became similar as PT increased, and the biochars produced at 550 °C demonstrated characteristics that have potential benefit as soil amendment for improving both C sequestration and nutrient dynamics. Copyright © 2015 Elsevier Ltd. All rights reserved.

Significant enhancement by biochar of caproate production via chain elongation.

PubMed

Liu, Yuhao; He, Pinjing; Shao, Liming; Zhang, Hua; Lü, Fan

2017-08-01

In this study, biochar was introduced into a chain elongation system to enhance the bioproduction of caproate and caprylate. The concentration of caproate increased to 21.1 g/L upon the addition of biochar, which is the highest level of caproate reported for such a system to date when ethanol was used as electron donor. The addition of biochar created a tougher system with more stable microorganism community structure for chain elongation, in which no obvious inhibition by products or substrates was observed, moreover, the lag phase was reduced 2.3-fold compared to the system without biochar. These reinforcement effect of biochar are attributed to the enhanced conductivity due to the significant enrichment of functional microorganisms via the microbial network surrounding smaller biochar particles, and via the adsorption on the rough surfaces or pores of larger particles, which facilitated electron transfer. Higher amounts of extracellular polymer substances and higher conductivity induced by biochar could contribute to the reinforcement effect in chain elongation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Lead and cadmium sorption mechanisms on magnetically modified biochars.

PubMed

Trakal, Lukáš; Veselská, Veronika; Šafařík, Ivo; Vítková, Martina; Číhalová, Sylva; Komárek, Michael

2016-03-01

This paper discusses Cd(II) and Pb(II) sorption efficiency of biochars modified by impregnation with magnetic particles. All selected biochar characteristics were significantly affected after the modification. More specifically, the cation exchange capacity increased after the modification, except for grape stalk biochar. However, the changes in the pH value, PZC, and BET surface after modification process were less pronounced. The metal loading rate was also significantly improved, especially for Cd(II) sorption on/in nut shield and plum stone biochars (10- and 16-times increase, respectively). The results indicated that cation exchange (as a metal sorption mechanism) was strengthened after Fe oxide impregnation, which limited the desorbed amount of tested metals. In contrast, the magnetization of grape stalk biochar reduced Pb(II) sorption in comparison with that of pristine biochar. Magnetic modification is, therefore, more efficient for biochars with well-developed structure and for more mobile metals, such as Cd(II). Copyright © 2015 Elsevier Ltd. All rights reserved.

Synergistic dye adsorption by biochar from co-pyrolysis of spent mushroom substrate and Saccharina japonica.

PubMed

Sewu, Divine Damertey; Boakye, Patrick; Jung, Hwansoo; Woo, Seung Han

2017-11-01

The potential of activating terrestrial biomass (spent mushroom substrate, SMS) with ash-laden marine biomass [kelp seaweed, KE] via co-pyrolysis in the field of adsorption was first investigated. KE biochar (KBC), SMS biochar (SMSBC), biochar (SK10BC) from 10%-KE added SMS, and biochar (ESBC) from KE-extract added SMS were used for the adsorption of cationic dye crystal violet (CV). ESBC had highest fixed carbon content (70.60%) and biochar yield (31.6%). SK10BC exhibited high ash content, abundant functional groups, coarser surface morphology and Langmuir maximum adsorptive capacity (610.1mg/g), which is 2.2 times higher than that of SMSBC (282.9mg/g). Biochar activated by a small amount of high ash-containing biomass such as seaweed via co-pyrolysis can serve as viable alternative adsorbent for cationic dye removal. Copyright © 2017 Elsevier Ltd. All rights reserved.

Letter Report for Characterization of Biochar

DOE Office of Scientific and Technical Information (OSTI.GOV)

Amonette, James E.

2013-04-09

On 27 November 2012, a bulk biochar sample was received for characterization of selected physical and chemical properties. The main purpose of the characterization was to help determine the degree to which biochar would be suitable as a soil amendment to aid in growth of plants. Towards this end, analyses to determine specific surface, pH, cation-exchange capacity, water retention, and wettability (i.e. surface tension) were conducted. A second objective was to determine how uniform these properties were in the sample. Towards this end, the sample was separated into fractions based on initial particle size and on whether the material wasmore » from the external surface or the internal portion of the particle. Based on the results, the biochar has significant liming potentials, significant cation-retention capacities, and highly variable plant-available moisture retention properties that, under the most favorable circumstances, could be helpful to plants. As a consequence, it would be quite suitable for addition to acidic soils and should enhance the fertility of those soils.« less

Escherichia coli removal in biochar-augmented biofilter: effect of infiltration rate, initial bacterial concentration, biochar particle size, and presence of compost.

PubMed

Mohanty, Sanjay K; Boehm, Alexandria B

2014-10-07

Bioretention systems and biofilters are used in low impact development to passively treat urban stormwater. However, these engineered natural systems are not efficient at removing fecal indicator bacteria, the contaminants responsible for a majority of surface water impairments. The present study investigates the efficacy of biochar-augmented model sand biofilters for Escherichia coli removal under a variety of stormwater bacterial concentrations and infiltration rates. Additionally, we test the role of biochar particle size and "presence of compost on model" biofilter performance. Our results show that E. coli removal in a biochar-augmented sand biofilter is ∼ 96% and is not greatly affected by increases in stormwater infiltration rates and influent bacterial concentrations, particularly within the ranges expected in field. Removal of fine (<125 μm) biochar particles from the biochar-sand biofilter decreased the removal capacity from 95% to 62%, indicating biochar size is important. Addition of compost to biochar-sand biofilters not only lowered E. coli removal capacity but also increased the mobilization of deposited bacteria during intermittent infiltration. This result is attributed to exhaustion of attachment sites on biochar by the dissolved organic carbon leached from compost. Overall, our study indicates that biochar has potential to remove bacteria from stormwater under a wide range of field conditions, but for biochar to be effective, the size should be small and biochar should be applied without compost. Although the results aid in the optimization of biofilter design, further studies are needed to examine biochar potential in the field over an entire rainy season.

Biochars derived from wasted marine macro-algae (Saccharina japonica and Sargassum fusiforme) and their potential for heavy metal removal in aqueous solution.

PubMed

Poo, Kyung-Min; Son, Eun-Bi; Chang, Jae-Soo; Ren, Xianghao; Choi, Yun-Jung; Chae, Kyu-Jung

2018-01-15

For the purpose of reusing wasted marine macro-algae generated during cultivation, harvesting, processing and selling processes, biochars derived from Saccharina japonica (known as kelp) and Sargassum fusiforme (known as hijikia) were characterized and their removal capacities for Cu, Cd, and Zn in aqueous solution were assessed. Feedstocks, S. japonica, S. fusiforme, and also pinewood sawdust as a control, were pyrolyzed at 250, 400, 500, 600 and 700 °C. In evaluating heavy metal removal capacities, SJB (S. japonica biochar) showed the best performance, with removal efficiencies of more than 98% for the three heavy metals when pyrolyzed at over 400 °C. SFB (S. fusiforme biochar) also showed good potential as an adsorbent, with removal efficiencies for the three heavy metals of more than 86% when pyrolyzed at over 500 °C. On the contrary, the maximum removal efficiencies of PSB (pinewood sawdust biochar) were 81%, 46%, and 47% for Cu, Cd, and Zn, respectively, even at 700 °C, the highest pyrolysis temperature. This demonstrates that marine macro-algae were advantageous in terms of production energy for removing heavy metals even at relatively low pyrolysis temperatures, compared with PSB. The excellent heavy metal adsorption capacities of marine macro-algae biochars were considered due to their higher pH and more oxygen-containing functional groups, although the specific surface areas of SJB and SFB were significantly lower than that of PSB. This research confirmed that the use of marine macro-algae as a heavy metal adsorbent was suitable not only in the removal of heavy metals, but also in terms of resource recycling and energy efficiency. Copyright © 2017 Elsevier Ltd. All rights reserved.

Bamboo- and pig-derived biochars reduce leaching losses of dibutyl phthalate, cadmium, and lead from co-contaminated soils.

PubMed

Qin, Peng; Wang, Hailong; Yang, Xing; He, Lizhi; Müller, Karin; Shaheen, Sabry M; Xu, Song; Rinklebe, Jörg; Tsang, Daniel C W; Ok, Yong Sik; Bolan, Nanthi; Song, Zhaoliang; Che, Lei; Xu, Xiaoya

2018-05-01

Biochar effect on the potential mobility of dibutyl phthalate (DBP), cadmium (Cd), and lead (Pb) in co-contaminated soils is not well investigated. A laboratory leaching study was conducted to evaluate the effect of biochars derived from bamboo (BB) and pig (PB) on the leachability of DBP, Cd, and Pb through soil columns packed with two soils with low or high organic carbon content (LOC; 0.35% C: HOC; 2.24% C) and spiked with DBP, Cd, and Pb. Application of PB to the LOC soil significantly (P < 0.05) reduced the leaching loss by up to 88% for DBP, 38% for Cd, and 71% for Pb, whereas its impact was insignificant in the HOC soil. The higher efficacy of PB in reducing the leaching of DBP, Cd, and Pb in the LOC soil than that of BB might be related to PB's higher specific surface area, surface alkalinity, pH, and mineral contents compared to those of BB. Co-contamination of Cd and Pb enhanced leaching of DBP in the LOC soil treated with PB, possibly by competition for the sorption sites. Leaching of DBP, Cd, and Pb were significantly (P < 0.05) higher in the LOC soil than in the HOC soil. This study revealed that the effectiveness of biochars was dependent on the soil organic carbon content. Application of PB to the LOC soil was effective in reducing the leaching risk of DBP, Cd, and Pb. Copyright © 2018 Elsevier Ltd. All rights reserved.

Removal of hexavalent chromium upon interaction with biochar under acidic conditions: mechanistic insights and application.

PubMed

Choudhary, Bharat; Paul, Debajyoti; Singh, Abhas; Gupta, Tarun

2017-07-01

Chromium pollution of soil and water is a serious environmental concern due to potential carcinogenicity of hexavalent chromium [Cr(VI)] when ingested. Eucalyptus bark biochar (EBB), a carbonaceous black porous material obtained by pyrolysis of biomass at 500 °C under oxygen-free atmosphere, was used to investigate the removal of aqueous Cr(VI) upon interaction with the EBB, the dominant Cr(VI) removal mechanism(s), and the applicability to treat Cr(VI)-contaminated wastewater. Batch experiments showed complete removal of aqueous Cr(VI) at pH 1-2; sorption was negligible at pH 1, but ~55% of total Cr was sorbed onto the EBB surface at pH 2. Detailed investigations on unreacted and reacted EBB through Fourier transform infrared spectroscopy and X-ray photoelectron spectrometry (XPS) indicate that the carboxylic groups in biochar played a dominant role in Cr(VI) sorption, whereas the phenolic groups were responsible for Cr(VI) reduction. The predominance of sorption-reduction mechanism was confirmed by XPS studies that indicated ~82% as Cr(III) and ~18% as Cr(VI) sorbed on the EBB surface. Significantly, Cr(VI) reduction was also facilitated by dissolved organic matter (DOM) extracted from biochar. This reduction was enhanced by the presence of biochar. Overall, the removal of Cr(VI) in the presence of biochar was affected by sorption due to electrostatic attraction, sorption-reduction mediated by surface organic complexes, and aqueous reduction by DOM. Relative dominance of the aqueous reduction mechanism depended on a critical biochar dosage for a given electrolyte pH and initial Cr(VI) concentration. The low-cost EBB developed here successfully removed all Cr(VI) in chrome tanning acidic wastewater and Cr(VI)-contaminated groundwater after pH adjustment, highlighting its potential applicability in effective Cr(VI) remediation.

Adsorption of Antibiotics on Graphene and Biochar in Aqueous Solutions Induced by π-π Interactions

PubMed Central

Peng, Bingquan; Chen, Liang; Que, Chenjing; Yang, Ke; Deng, Fei; Deng, Xiaoyong; Shi, Guosheng; Xu, Gang; Wu, Minghong

2016-01-01

The use of carbon based materials on the removal of antibiotics with high concentrations has been well studied, however the effect of this removal method is not clear on the actual concentration of environments, such as the hospital wastewater, sewage treatment plants and aquaculture wastewater. In this study, experimental studies on the adsorption of 7 antibiotics in environmental concentration of aqueous solutions by carbon based materials have been observed. Three kinds of carbon materials have shown very fast adsorption to antibiotics by liquid chromatography–tandem mass spectrometry (LC-MS-MS) detection, and the highest removal efficiency of antibiotics could reach to 100% within the range of detection limit. Surprisedly, the adsorption rate of graphene with small specific surface area was stronger than other two biochar, and adsorption rate of the two biochar which have approximate specific surface and different carbonization degree, was significantly different. The key point to the present observation were the π-π interactions between aromatic rings on adsorbed substance and carbon based materials by confocal laser scanning microscope observation. Moreover, adsorption energy markedly increased with increasing number of the π rings by using the density functional theory (DFT), showing the particular importance of π-π interactions in the adsorption process. PMID:27534975

Adsorption of Antibiotics on Graphene and Biochar in Aqueous Solutions Induced by π-π Interactions

NASA Astrophysics Data System (ADS)

Peng, Bingquan; Chen, Liang; Que, Chenjing; Yang, Ke; Deng, Fei; Deng, Xiaoyong; Shi, Guosheng; Xu, Gang; Wu, Minghong

2016-08-01

The use of carbon based materials on the removal of antibiotics with high concentrations has been well studied, however the effect of this removal method is not clear on the actual concentration of environments, such as the hospital wastewater, sewage treatment plants and aquaculture wastewater. In this study, experimental studies on the adsorption of 7 antibiotics in environmental concentration of aqueous solutions by carbon based materials have been observed. Three kinds of carbon materials have shown very fast adsorption to antibiotics by liquid chromatography-tandem mass spectrometry (LC-MS-MS) detection, and the highest removal efficiency of antibiotics could reach to 100% within the range of detection limit. Surprisedly, the adsorption rate of graphene with small specific surface area was stronger than other two biochar, and adsorption rate of the two biochar which have approximate specific surface and different carbonization degree, was significantly different. The key point to the present observation were the π-π interactions between aromatic rings on adsorbed substance and carbon based materials by confocal laser scanning microscope observation. Moreover, adsorption energy markedly increased with increasing number of the π rings by using the density functional theory (DFT), showing the particular importance of π-π interactions in the adsorption process.

Carbon dioxide emissions from semi-arid soils amended with biochar alone or combined with mineral and organic fertilizers.

PubMed

Fernández, José M; Nieto, M Aurora; López-de-Sá, Esther G; Gascó, Gabriel; Méndez, Ana; Plaza, César

2014-06-01

Semi-arid soils cover a significant area of Earth's land surface and typically contain large amounts of inorganic C. Determining the effects of biochar additions on CO2 emissions from semi-arid soils is therefore essential for evaluating the potential of biochar as a climate change mitigation strategy. Here, we measured the CO2 that evolved from semi-arid calcareous soils amended with biochar at rates of 0 and 20tha(-1) in a full factorial combination with three different fertilizers (mineral fertilizer, municipal solid waste compost, and sewage sludge) applied at four rates (equivalent to 0, 75, 150, and 225kg potentially available Nha(-1)) during 182 days of aerobic incubation. A double exponential model, which describes cumulative CO2 emissions from two active soil C compartments with different turnover rates (one relatively stable and the other more labile), was found to fit very well all the experimental datasets. In general, the organic fertilizers increased the size and decomposition rate of the stable and labile soil C pools. In contrast, biochar addition had no effects on any of the double exponential model parameters and did not interact with the effects ascribed to the type and rate of fertilizer. After 182 days of incubation, soil organic and microbial biomass C contents tended to increase with increasing the application rates of organic fertilizer, especially of compost, whereas increasing the rate of mineral fertilizer tended to suppress microbial biomass. Biochar was found to increase both organic and inorganic C contents in soil and not to interact with the effects of type and rate of fertilizer on C fractions. As a whole, our results suggest that the use of biochar as enhancer of semi-arid soils, either alone or combined with mineral and organic fertilizers, is unlikely to increase abiotic and biotic soil CO2 emissions. Copyright © 2014 Elsevier B.V. All rights reserved.

Retention efficiency of Cd, Pb and Zn from agricultural by-products activated carbon and biochar under laboratory conditions

NASA Astrophysics Data System (ADS)

Coscione, Aline; Ramos, Barbara

2015-04-01

The immobilization of inorganic contaminants by using biochar in soils has played an increasingly important role and it is seen as an attractive alternative for the remediation of heavy metals. Although, the production of activated carbon (CA) from agricultural by-products has received special attention, the activation of the the organic source has been studied in order to increase its porposity, surface area and chemical polarity, resulting in higher adsorption of metals. Therefore, this study aimed to evaluate the effectiveness of BC and CA samples, obtained from a eucalyptus husks and cane sugar bagasse after activation with 20% phosphoric acid and pyrolyzed at 450oC in the retention of Zn, Cd and Pb using contaminated individual solutions. The experiment was performed using samples of activated carbon of eucalyptus husk (CCA), eucalyptus husk biochar (BC), activated carbon of sugar cane bagasse (CBA) and sugar cane bagasse biochar (BB) previously treated with Zn, Cd (range of tested solution from 0.1 up to 12 mmol L-1) and Pb (from 0.1 up 50 mmol L-1) which were submitted to stirring with ammonium acetate solution at pH 4.9 for 48 h. The results obtained were adjusted with Langmuir desorptiom isotherms. The pH of the resulting solution, were the meatls were analyse, was measure and remained in the range 4.9 - 5.0. The lower pH found in activated samples (range 2.4-2.5) resulted in larger desorption of metals than the biochar samples (pH of 9.7 for BC and 7.0 for BB). This result is surprising since for the biochar samples it was expected that any precipated metals were dissolved by the desorption solution in addition to metals released by ion exchange. Although the desorption results of activated samoels is still unclear, hich we belive may be explaibed by some adicitonal insterumental analysis, biochar samples showed better potential for application in contaminated soils than the previous.

Effects of humic acid and heavy metals on the sorption of polar and apolar organic pollutants onto biochars.

PubMed

Wang, Fei; Sun, Hongwen; Ren, Xinhao; Liu, Yarui; Zhu, Hongkai; Zhang, Peng; Ren, Chao

2017-12-01

The effects of humic acid (HA) and heavy metals (Cu 2+ and Ag + ) on the sorption of polar and apolar organic pollutants onto biochars that were produced at temperatures of 200 °C (BC200) and 700 °C (BC700) were studied. Due to the plentiful polar functional groups on BC200, cationic propranolol exhibited higher levels of sorption than naphthalene on BC200 while naphthalene and propranolol showed similar sorption capacities on BC700. HA changed the characteristics of biochars and generally inhibited the sorption of target organic pollutants on biochars; however, enhancement occurred in some cases depending on the pollutants involved and their concentrations, biochars used and the addition sequences and concentrations of HA. On BC200, HA modifications mainly influenced sorption by decreasing its polarity and increasing its aromaticity, while on BC700, the surface area and pore volume greatly decreased due to the pore-blocking effects of HA. Residue dissolved HA in solution may also contribute to sorption inhibition. Complexation between polar functional groups on BC200 and heavy metals slightly enhanced the sorption of neutral naphthalene and significantly enhanced that of anionic 4-nitro-1-naphtol, while limited the sorption of cationic propranolol. Heavy metals together with their associated water molecules decreased the sorption of target chemicals on BC700 via pore-filling or pore-mouth-covering. Inhibition of heavy metals for 4-nitro-1-naphthol was found to be the weakest due to the bridge effects of heavy metals between 4-nitro-1-naphtol and BC700. The higher polarizability of Ag + led to the increase of its sorption on biochars in the presence of organic aromatic pollutants. The results of the present study shed light on the sorption mechanisms of bi-solute systems and enable us to select suitable biochar sorbents when chemicals co-exist. Copyright © 2017. Published by Elsevier Ltd.

Sorption of tetracycline on biochar derived from rice straw under different temperatures

PubMed Central

Wang, Hua; Chu, Yixuan; Huang, Fang; Song, Yali; Xue, Xiangdong

2017-01-01

Biochars produced from the pyrolysis of waste biomass under limited oxygen conditions could serve as adsorbents in environmental remediation processes. Biochar samples derived from rice straw that were pyrolyzed at 300 (R300), 500 (R500) and 700°C (R700) were used as adsorbents to remove tetracycline from an aqueous solution. Both the Langmuir and Freundlich models fitted the adsorption data well (R2 > 0.919). The adsorption capacity increased with pyrolysis temperature. The R500 and R700 samples exhibited relative high removal efficiencies across a range of initial tetracycline concentrations (0.5mg/L-32mg/L) with the maximum (92.8%–96.7%) found for adsorption on R700 at 35°C. The relatively high surface area of the R700 sample and π–π electron-donor acceptor contributed to the high adsorption capacities. A thermodynamic analysis indicated that the tetracycline adsorption process was spontaneous and endothermic. The pH of solution was also found to influence the adsorption processes; the maximum adsorption capacity occurred at a pH of 5.5. These experimental results highlight that biochar derived from rice straw is a promising candidate for low-cost removal of tetracycline from water. PMID:28792530

The sorptive and reductive capacities of biochar supported nanoscaled zero-valent iron (nZVI) in relation to its crystallite size.

PubMed

Wang, Shengsen; Zhou, Yanxia; Gao, Bin; Wang, Xiaozhi; Yin, Xianqiang; Feng, Ke; Wang, Jun

2017-11-01

In this work, nZVI was immobilized by bamboo derived biochars (nZVI/BB), hydrogen peroxide (H 2 O 2 ) (nZVI/PBB) and nitric acid (HNO 3 ) (nZVI/HBB) modified BB. H 2 O 2 and HNO 3 deceased surface area and pore volume of pristine biochars. Total iron (Fe) contents were 16.50, 24.40, and 13.08% for nZVI/BB, nZVI/PBB and nZVI/HBB, respectively. The X-ray diffraction revealed that nZVI in biochar matrix was dominantly metallic Fe coated with Fe oxides. The transmission electron microscopy indicated nZVI particle sizes were 41.5, 30.5 and 6.1 nm for nZVI/BB, nZVI/HBB and nZVI/PBB, respectively. The removal capacities of arsenate (AsV) and silver ions (Ag + ) by nZVI nanocomposites were compared in a batch experiment. Greater reductive removal of Ag + (1217 g kg -1 nZVI) and sorptive removal of AsV (109.1 g kg -1 nZVI) were achieved in nZVI/PBB, indicating smaller-sized nZVI was more reactive. Thus, particle size of nZVI affected the sorptive and reductive capacities for AsV and Ag + . Copyright © 2017 Elsevier Ltd. All rights reserved.

Anatomy of a field trial: Wood-based biochar and compost influences a Pacific Northwest soil

USDA-ARS?s Scientific Manuscript database

Biochar land application research in elevated rainfall areas (980 millimeters of annual rainfall) of the U.S. Pacific Northwest is lacking. A proof-of-concept field study examined the effects of spruce-pine-fir wood chip biochar (slow pyrolysis; 450-500 degrees Celsius; 35 megagrams per hectare), d...

Crop residue decomposition in Minnesota biochar amended plots

NASA Astrophysics Data System (ADS)

Weyers, S. L.; Spokas, K. A.

2014-02-01

Impacts of biochar application at laboratory scales are routinely studied, but impacts of biochar application on decomposition of crop residues at field scales have not been widely addressed. The priming or hindrance of crop residue decomposition could have a cascading impact on soil processes, particularly those influencing nutrient availability. Our objectives were to evaluate biochar effects on field decomposition of crop residue, using plots that were amended with biochars made from different feedstocks and pyrolysis platforms prior to the start of this study. Litterbags containing wheat straw material were buried below the soil surface in a continuous-corn cropped field in plots that had received one of seven different biochar amendments or a non-charred wood pellet amendment 2.5 yr prior to start of this study. Litterbags were collected over the course of 14 weeks. Microbial biomass was assessed in treatment plots the previous fall. Though first-order decomposition rate constants were positively correlated to microbial biomass, neither parameter was statistically affected by biochar or wood-pellet treatments. The findings indicated only a residual of potentially positive and negative initial impacts of biochars on residue decomposition, which fit in line with established feedstock and pyrolysis influences. Though no significant impacts were observed with field-weathered biochars, effective soil management may yet have to account for repeat applications of biochar.

Optimizing biochars to mitigate N2O emissions in Mediterranean areas

NASA Astrophysics Data System (ADS)

Cayuela, Maria Luz; Sanchez-Garcia, Maria; Roig, Asuncion; Sanchez-Monedero, Miguel Angel

2017-04-01

Some of the most productive agricultural soils stand in Mediterranean-type climate areas of the world (e.g. California's Central Valley, Andalucia region in South Spain, and Lombardy region in Italy). Many of these soils are under intensive agricultural production, bearing the addition of substantial amounts of N fertilizers, which are known to promote soil N2O emissions. Laboratory studies have shown the potential of biochar to decrease N2O emissions in soils from Mediterranean areas. These soils generally have alkaline pH and low concentrations of organic C and several laboratory experiments found that applying biochar at a rate of 2% in weight could decrease N2O emissions up to 90%. However, field studies carried out in areas of California, Italy and Spain (all under Mediterranean climate) showed none or very limited N2O mitigation with biochar. We postulate that this discrepancy may be because biochar-soil combinations were not optimal in field studies and that developing biochars adjusted to specific soil properties is crucial for their successful application to mitigate N2O emissions. Thus, in this study we aimed at (i) collecting and characterizing a variety of the most representative Mediterranean agricultural residues (olive tree, almond and orange tree pruning, olive mill waste, rice straw, horticultural residues, etc.), (ii) exploring their suitability as feedstocks for biochar production and (iii) analyzing their impact on N2O emissions in a Mediterranean agricultural soil. Biochars were produced by slow pyrolysis with a heating rate of 5˚C min-1 at two pyrolysis temperatures (400 and 600˚C) and a retention time of two hours. Soil incubations were set up simulating conditions of highly intensive crop production (high N fertilization, high moisture) to test how the biochars produced from different feedstocks and under two pyrolysis temperatures influence N2O emissions. Our starting hypothesis was that it is possible to optimize biochar characteristics (by appropriately selecting original feedstocks and pyrolysis conditions) in order to mitigate N2O emissions in Mediterranean agricultural soils. Acknowledgements: This contribution was possible thanks to Fundación Séneca (Agencia Regional de Ciencia y Tecnología de la region de Murcia). Grant number 19281/PI/14

Assessing biochar applications and repeated Brassica juncea L. production cycles to remediate Cu contaminated soil.

PubMed

Gonzaga, Maria Isidoria Silva; Mackowiak, Cheryl; Quintão de Almeida, André; Wisniewski, Alberto; Figueiredo de Souza, Danyelle; da Silva Lima, Idamar; Nascimento de Jesus, Amanda

2018-06-01

Copper contamination and toxicity in soils is a worldwide problem, especially in areas where copper-based fungicides are applied. Indian mustard (Brassica juncea L.) plants are used in phytoremediation and are also edible crops commonly cultivated in organic agricultural areas. Application of biochar to Cu contaminated soils may reduce Cu availability and uptake, thereby allowing for greater Indian mustard production. A (3 × 2) + 1) experiment in a randomized complete block design was used to evaluate the effect of three different biochars (coconut shell, orange bagasse and sewage sludge) and two application rates (30 and 60 t ha -1 ) on Cu uptake by Indian mustard during three successive growth cycles and Cu immobilization in soil, under greenhouse conditions. Coconut husk biochar did not influence available soil Cu; however, its presence increased shoot Cu uptake by 117% and 38% in the two last growth cycles. Orange bagasse biochar, at the 60 t ha -1 application rate, reduced Cu availability, but it was not effective in reducing Cu uptake. Sewage sludge biochar did not affect Cu availability and caused an approximated 100% increase in shoot Cu uptake at the highest application rate. Therefore, the orange bagasse biochar is the most effective whereas the sewage sludge biochar is the least in Cu immobilization. None of the biochars was shown to be suitable as soil amendment to reduce the uptake of Cu by Indian mustard. However, coconut shell and sewage sludge biochar can be effectively applied to soil as an auxiliary tool to remediate Cu-contaminated soils. Copyright © 2018. Published by Elsevier Ltd.

Leaching of mixtures of biochar and fly ash

DOE Office of Scientific and Technical Information (OSTI.GOV)

Palumbo, Anthony V.; Porat, Iris; Phillips, Jana R.

2009-06-22

Increasing atmospheric levels of greenhouse gases, especially CO2, and their effects on global temperature have led to interest in the possibility of carbon storage in terrestrial environments. Both the residual char from biomass pyrolysis (biochar) and fly ash from coal combustion have the potential to significantly expand terrestrial sequestration options. Both biochar and fly ash also have potentially beneficial effects on soil properties. Fly ash has been shown to increase porosity, water-holding capacity, pH, conductivity, and dissolved SO42-, CO32-, Cl- and basic cations. Adding biochar to soil generally raises pH, increases total nitrogen and total phosphorous, encourages greater root development,more » improves cation exchange capacity and decreases available aluminum. A combination of these benefits likely is responsible for observed increases in yields for crops such as corn and sugarcane. In addition, it has been found that soils with added biochar emit lower amounts of other greenhouse gases (methane and nitrous oxide) than do unamended soils. Biochar and fly ash amendments may be useful in promoting terrestrial carbon sequestration on currently underutilized and degraded lands. For example, about 1% of the US surface lands consist of previously mined lands or highway rights-of-way. Poorly managed lands could count for another 15% of US area. Biochar and fly ash amendments could increase productivity of these lands and increase carbon storage in the soil. Previous results showed minimal leaching of organic carbon and metals from a variety of fly ashes. In the present study, we examined the properties of mixtures of biochar, fly ash, and soil and evaluated the leaching of organic carbon and metals from these mixtures. The carbon sorption experiments showed release of carbon from biochar, rather than sorption, except at the highest concentrations in the Biochar HW sample. Similar results were obtained by others for oxidative leaching of bituminous coal, in which more C was released as dissolved C than was oxidized to CO2 by the oxygen in water. We confirmed that both fly ash and two types of biochar (oak char [OKEB], and hardwood [HW] char) exhibited minimal leaching of heavy metals including Cr, Ni, Zn, Ga, and Ag, and no detectable leaching of Pb or Cd (data not shown) under the conditions tested. The Biochar HW had a slightly higher C/N ratio (334) and pH (7.7) than did the Biochar OKEB (284 and 6.5). There was no toxicity exhibited by the fly ash (not shown) or biochar leachates as measured by the Microtox© assay under the conditions tested. In previous results no toxicity was reported in testing the fly ash samples except for one high-pH sample. The most notable leachate component from both types of biochar, but not the fly ash, was organic carbon with the HW biochar leaching less organic carbon than the OKEB biochar (5.71 ppm vs. 59.3 ppm). Alone (in batch sorption experiments), or in mixtures of 90% soil and 10% biochar (column studies), we noted significant loss of carbon from the biochar into soluble components. However, when we added fly ash to the column experiments (80% soil, 10% fly ash, and 10% biochar) we observed significant decreases in the amounts of C leached (20% for HW, and 47% for OKEB). The results indicate that applying a combination of fly ash and biochar may result in maximizing the amount of carbon sequestration in soil while also increasing beneficial soil properties and fertility. The lower amount of carbon leached from the HW biochar compared to the OKEB biochar is likely due to the more recalcitrant form of the carbon in the HW char, due to its preparation at a higher temperature (600 ºC) than the OKEB biochar (450 ºC). High heat treatment temperatures during biochar preparation increase both the total carbon content of the biochar and the proportion of the carbon that is present in fused aromatic rings resistant to chemical and physical degradation.« less

Organic compounds leached from fast pyrolysis mallee leaf and bark biochars.

PubMed

Lievens, Caroline; Mourant, Daniel; Gunawan, Richard; Hu, Xun; Wang, Yi

2015-11-01

Characterization of organic compounds leached from biochars is essential in assessing the possible toxicity of the biochar to the soils' biota. In this study the nature of the leached organic compounds from Mallee biochars, produced from pyrolysis of Mallee leaf and bark in a fluidised-bed pyrolyser at 400 and 580°C was investigated. Light bio-oil compounds and aromatic organic compounds were investigated. The 'bio-oil like' light compounds from leaf and bark biochars 'surfaces were obtained after leaching the chars with a solvent, suitable to dissolve the respective bio-oils. GC/MS was implemented to investigate the leachates. Phenolics, which are potentially harmful toxins, were detected and their concentration shown to be dependent on the char's origin and the char production temperature. Further, to simulate biochars amendment to soils, the chars were leached with water. The water-leached aromatic compounds from leaf and bark biochars were characterized using UV-fluorescence spectroscopy. Those results suggested that biochars contain leachable compounds of which the nature and amount is dependent on the biomass feedstock, pyrolysis temperature and leaching time. Copyright © 2014 Elsevier Ltd. All rights reserved.

Catalytic degradation of the soil fumigant 1,3-dichloropropene in aqueous biochar slurry.

PubMed

Qin, Jiaolong; Cheng, Yuxiao; Sun, Mingxing; Yan, Lili; Shen, Guoqing

2016-11-01

Biochar has been explored as a cost-effective sorbent of contaminants, such as soil fumigant. However, contaminant-loaded biochar probably becomes a source of secondary air pollution. In this study, biochars developed from cow manure and rice husk at 300°C or 700°C were used to investigate the catalytic degradation of the soil fumigant 1,3-dichloropropene (1,3-D) in aqueous biochar slurry. Results showed that the adsorption of 1,3-D on the biochars was influenced by Langmuir surface monolayer adsorption. The maximum adsorption capacity of cow manure was greater than that of rice husk at the same pyrolysis temperature. Batch experiments revealed that 1,3-D degradation was improved in aqueous biochar slurry. The most rapid 1,3-D degradation occurred on cow manure-derived biochar produced at 300°C (C-300), with t1/2=3.47days. The degradation efficiency of 1,3-D on C-300 was 95.52%. Environmentally persistent free radicals (EPFRs) in biochars were detected via electron paramagnetic resonance (EPR) techniques. Dissolved organic matter (DOM) and hydroxyl radical (·OH) in biochars were detected by using a fluorescence spectrophotometer coupled with a terephthalic acid trapping method. The improvement of 1,3-D degradation efficiency may be attributed to EPFRs and DOM in aqueous biochar slurry. Our results may pose implications in the development of effective reduction strategies for soil fumigant emission with biochar. Copyright © 2016 Elsevier B.V. All rights reserved.

Microalgal-biochar immobilized complex: A novel efficient biosorbent for cadmium removal from aqueous solution.

PubMed

Shen, Ying; Li, Huan; Zhu, Wenzhe; Ho, Shih-Hsin; Yuan, Wenqiao; Chen, Jianfeng; Xie, Youping

2017-11-01

The feasibility of the bioremediation of cadmium (Cd) using microalgal-biochar immobilized complex (MBIC) was investigated. Major operating parameters (e.g., pH, biosorbent dosage, initial Cd(II) concentration and microalgal-biochar ratio) were varied to compare the treatability of viable algae (Chlorella sp.), biochar and MBIC. The biosorption isotherms obtained by using algae or biochar were found to have satisfactory Langmuir predictions, while the best fitting adsorption isotherm model for MBIC was the Sips model. The maximum Cd(II) adsorption capacity of MBIC with a Chlorella sp.: biochar ratio of 2:3 (217.41mgg -1 ) was higher than that of Chlorella sp. (169.92mgg -1 ) or biochar (95.82mgg -1 ) alone. The pseudo-second-order model fitted the biosorption process of MBIC well (R 2 >0.999). Moreover, zeta potential, SEM and FTIR studies revealed that electrostatic attraction, ion exchange and surface complexation were the main mechanisms responsible for Cd removal when using MBIC. Copyright © 2017 Elsevier Ltd. All rights reserved.

Biochar amendment immobilizes lead in rice paddy soils and reduces its phytoavailability

NASA Astrophysics Data System (ADS)

Li, Honghong; Liu, Yuting; Chen, Yanhui; Wang, Shanli; Wang, Mingkuang; Xie, Tuanhui; Wang, Guo

2016-08-01

This study aimed to determine effects of rice straw biochar on Pb sequestration in a soil-rice system. Pot experiments were conducted with rice plants in Pb-contaminated paddy soils that had been amended with 0, 2.5, and 5% (w/w) biochar. Compared to the control treatment, amendment with 5% biochar resulted in 54 and 94% decreases in the acid soluble and CaCl2-extractable Pb, respectively, in soils containing rice plants at the maturity stage. The amount of Fe-plaque on root surfaces and the Pb concentrations of the Fe-plaque were also reduced in biochar amended soils. Furthermore, lead species in rice roots were determined using Pb L3-edge X-ray absorption near edge structure (XANES), and although Pb-ferrihydrite complexes dominated Pb inventories, increasing amounts of organic complexes like Pb-pectins and Pb-cysteine were found in roots from the 5% biochar treatments. Such organic complexes might impede Pb translocation from root to shoot and subsequently reduce Pb accumulation in rice with biochar amendment.

Effects of biochar, waste water irrigation and fertilization on soil properties in West African urban agriculture.

PubMed

Häring, Volker; Manka'abusi, Delphine; Akoto-Danso, Edmund K; Werner, Steffen; Atiah, Kofi; Steiner, Christoph; Lompo, Désiré J P; Adiku, Samuel; Buerkert, Andreas; Marschner, Bernd

2017-09-06

In large areas of sub-Saharan Africa crop production must cope with low soil fertility. To increase soil fertility, the application of biochar (charred biomass) has been suggested. In urban areas, untreated waste water is widely used for irrigation because it is a nutrient-rich year-round water source. Uncertainty exists regarding the interactions between soil properties, biochar, waste water and fertilization over time. The aims of this study were to determine these interactions in two typical sandy, soil organic carbon (SOC) and nutrient depleted soils under urban vegetable production in Tamale (Ghana) and Ouagadougou (Burkina Faso) over two years. The addition of biochar at 2 kg m -2 made from rice husks and corn cobs initially doubled SOC stocks but SOC losses of 35% occurred thereafter. Both biochar types had no effect on soil pH, phosphorous availability and effective cation exchange capacity (CEC) but rice husk biochar retained nitrogen (N). Irrigation with domestic waste water increased soil pH and exchangeable sodium over time. Inorganic fertilization alone acidified soils, increased available phosphorous and decreased base saturation. Organic fertilization increased SOC, N and CEC. The results from both locations demonstrate that the effects of biochar and waste water were less pronounced than reported elsewhere.

Biochars with excellent Pb(II) adsorption property produced from fresh and dehydrated banana peels via hydrothermal carbonization.

PubMed

Zhou, Nan; Chen, Honggang; Xi, Junting; Yao, Denghui; Zhou, Zhi; Tian, Yun; Lu, Xiangyang

2017-05-01

Fresh and dehydrated banana peels were used as biomass feedstock to produce highly effective sorbent biochars through a facile one-step hydrothermal carbonization approach with 20%vol phosphoric acid as the reaction medium. The elemental ratio of oxygen content of the two as-prepared biochars were about 20%, and the FT-IR analysis confirmed the existence of abundant surface functional groups such as hydroxyl and carboxyl which greatly enhanced the adsorption performance. The sorbents showed excellent lead clarification capability of 359mg·g -1 and 193mg·g -1 for dehydrated and fresh banana peels based biochars, respectively. The change of the CO/OCO and the appearance of PbO/PbOC on the surface after adsorption confirmed that the ion exchange might be the dominant mechanism. The dehydration and pulverization pre-treatment and the addition of phosphoric acid can benefit the formation of those functional groups and hydrothermal carbonization can be a promising method to transfer biomass like fruit peels into biochars with excellent adsorption performance. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evaluation of sewage sludge and slow pyrolyzed sewage sludge-derived biochar for adsorption of phenanthrene and pyrene.

PubMed

Zielińska, Anna; Oleszczuk, Patryk

2015-09-01

The present study investigated the sorption of phenanthrene (PHE) and pyrene (PYR) by sewage sludges and sewage sludge-derived biochars. The organic carbon normalized distribution coefficient (log K(OC) for C(w) = 0.01 S(w)) for the sewage sludges ranged from 5.62 L kg(-1) to 5.64 L kg(-1) for PHE and from 5.72 L kg(-1) to 5.75 L kg(-1) for PYR. The conversion of sewage sludges into biochar significantly increased their sorption capacity. The value of log K(OC) for the biochars ranged from 5.54 L kg(-1) to 6.23 L kg(-1) for PHE and from 5.95 L kg(-1) to 6.52 L kg(-1) for PYR depending on temperature of pyrolysis. The dominant process was monolayer adsorption in the micropores and/or multilayer surface adsorption (in the mesopores), which was indicated by the significant correlations between log K(OC) and surface properties of biochars. PYR was sorbed better on the tested materials than PHE. Copyright © 2015 Elsevier Ltd. All rights reserved.

Biochar Mechanisms of Heavy Metal Sorption and Potential Utility

NASA Astrophysics Data System (ADS)

Ippolito, J.

2015-12-01

Mining-affected lands are a global issue; in the USA alone there are an estimated 500,000 abandoned mines encompassing hundreds of thousands of hectares. Many of these sites generate acidic mine drainage that causes release of heavy metals, and subsequently degradation in environmental quality. Because of its potential liming characteristics, biochar may play a pivotal role as a soil amendment in future mine land reclamation. However, to date, most studies have focused on the use of biochar to sorb metals from solution. Previous studies suggest that metals are complexed by biochar surface function groups (leading to ion exchange, complexation), coordination with Pi electrons (C=C) of carbon, and precipitation of inorganic mineral phases. Several recent studies have focused on the use of biochar for amending mine land soils, showing that biochar can indeed reduce heavy metal lability, yet the mechanism(s) behind labile metal reduction have yet to be established. In a proof-of-concept study, we added lodgepole pine, tamarisk, and switchgrass biochar (0, 5, 10, 15% by weight; 500 oC) to four different western US mine land soils affected by various heavy metals (Cd, Cu, Mn, Pb, Zn). Extraction with 0.01M CaCl2 showed that increasing biochar application rate significantly decreased 'bioaccessible' metals in almost all instances. A concomitant increase in solution pH was observed, suggesting that metals may be rendered bio-inaccessible through precipitation as carbonate or (hydr)oxide phases, or sorbed onto mineral surfaces. However, this was only supposition and required further research. Thus, following the 0.01M CaCl2 extraction, biochar-soil mixtures were air-dried and metals were further extracted using the four-step BCR sequential removal procedure. Results from selective extraction suggest that, as compared to the controls, most metals in the biochar-amended mine land soils were associated with exchange sites, carbonate, and oxide phases. Biochar may play a pivotal role as a soil amendment in the future of mine land reclamation, although elevated pH levels should be maintained to prolong sequestration while lessening the possibility of metal resolubilization.

Impact of biochar produced from post-harvest residue on the adsorption behavior of diesel oil on loess soil.

PubMed

Jiang, Yu Feng; Sun, Hang; Yves, Uwamungu J; Li, Hong; Hu, Xue Fei

2016-02-01

The primary objective of this study was to investigate the effect of biochar, produced from wheat residue at different temperatures, on the adsorption of diesel oil by loess soil. Kinetic and equilibrium data were processed to understand the adsorption mechanism of diesel by biochar-affected loess soil; dynamic and thermodynamic adsorption experiments were conducted to characterize this adsorption. The surface features and chemical structure of biochar, modified at varying pyrolytic temperatures, were investigated using surface scanning electron microscopy and Fourier transform infrared analysis. The kinetic data showed that the adsorption of diesel oil onto loess soil could be described by a pseudo-second-order kinetic model, with the rate-controlling step being intraparticle diffusion. However, in the presence of biochar, boundary layer control and intraparticle diffusion were both involved in the adsorption. Besides, the adsorption equilibrium data were well described by the Freundlich isothermal model. The saturated adsorption capacity weakened as temperature increased, suggesting a spontaneous exothermic process. Thermodynamic parameter analysis showed that adsorption was mainly a physical process and was enhanced by chemical adsorption. The adsorption capacity of loess soil for diesel oil was weakened with increasing pH. The biochar produced by pyrolytic wheat residue increased the adsorption behavior of petroleum pollutants in loess soil.

Co-production of biochar, bio-oil and syngas from halophyte grass (Achnatherum splendens L.) under three different pyrolysis temperatures.

PubMed

Irfan, Muhammad; Chen, Qun; Yue, Yan; Pang, Renzhong; Lin, Qimei; Zhao, Xiaorong; Chen, Hao

2016-07-01

In the present study, pyrolysis of Achnatherum splendens L. was performed under three different pyrolysis temperature (300, 500, and 700°C) to investigate the characteristics of biochar, bio-oil, and syngas. Biochar yield decreased from 48% to 24%, whereas syngas yield increased from 34% to 54% when pyrolysis temperature was increased from 300 to 700°C. Maximum bio-oil yield (27%) was obtained at 500°C. The biochar were characterized for elemental composition, surface, and adsorption properties. The results showed that obtained biochar could be used as a potential soil amendment. The bio-oil and syngas co-products will be evaluated in the future as bioenergy sources. Overall, our results suggests that A. splendens L. could be utilized as a potential feedstock for biochar and bioenergy production through pyrolytic route. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Emissions and Char Quality of Flame-Curtain "Kon Tiki" Kilns for Farmer-Scale Charcoal/Biochar Production

PubMed Central

Cornelissen, Gerard; Pandit, Naba Raj; Taylor, Paul; Pandit, Bishnu Hari; Sparrevik, Magnus; Schmidt, Hans Peter

2016-01-01

Flame Curtain Biochar Kilns Pyrolysis of organic waste or woody materials yields charcoal, a stable carbonaceous product that can be used for cooking or mixed into soil, in the latter case often termed "biochar". Traditional kiln technologies for charcoal production are slow and without treatment of the pyrolysis gases, resulting in emissions of gases (mainly methane and carbon monoxide) and aerosols that are both toxic and contribute to greenhouse gas emissions. In retort kilns pyrolysis gases are led back to a combustion chamber. This can reduce emissions substantially, but is costly and consumes a considerable amount of valuable ignition material such as wood during start-up. To overcome these problems, a novel type of technology, the Kon-Tiki flame curtain pyrolysis, is proposed. This technology combines the simplicity of the traditional kiln with the combustion of pyrolysis gases in the flame curtain (similar to retort kilns), also avoiding use of external fuel for start-up. Biochar Characteristics A field study in Nepal using various feedstocks showed char yields of 22 ± 5% on a dry weight basis and 40 ± 11% on a C basis. Biochars with high C contents (76 ± 9%; n = 57), average surface areas (11 to 215 m2 g-1), low EPA16—PAHs (2.3 to 6.6 mg kg-1) and high CECs (43 to 217 cmolc/kg)(average for all feedstocks, mainly woody shrubs) were obtained, in compliance with the European Biochar Certificate (EBC). Gas Emission Factors Mean emission factors for the flame curtain kilns were (g kg-1 biochar for all feedstocks); CO2 = 4300 ± 1700, CO = 54 ± 35, non-methane volatile organic compounds (NMVOC) = 6 ± 3, CH4 = 30 ± 60, aerosols (PM10) = 11 ± 15, total products of incomplete combustion (PIC) = 100 ± 83 and NOx = 0.4 ± 0.3. The flame curtain kilns emitted statistically significantly (p<0.05) lower amounts of CO, PIC and NOx than retort and traditional kilns, and higher amounts of CO2. Implications With benefits such as high quality biochar, low emission, no need for start-up fuel, fast pyrolysis time and, importantly, easy and cheap construction and operation the flame curtain technology represent a promising possibility for sustainable rural biochar production. PMID:27191397

Direct impacts of biochar on N2O production during denitrification by a soil microbial community

NASA Astrophysics Data System (ADS)

Mishra, Akanksha; Harter, Johannes; Hagemann, Nikolas; Kappler, Andreas

2017-04-01

Biochar, i.e. biomass heated under O2 limitation to 350-1000°C (pyrolysis), is suggested as a beneficial soil amendment to mitigate climate change and to maintain and restore the fertility of agro-ecosystems. Its stability enables long-term carbon sequestration and biochar effectively reduces soil-borne N2O emissions. Biochar's ability to reduce N2O emissions is well recognized through field and laboratory experiments as well as meta-analyses. However, the underlying mechanisms remain widely debated. Microbial nitrogen transformations, especially denitrification, the stepwise reduction of nitrate/nitrite via NO and N2O to N2, are considered to be a major source of N2O emissions. Soil microcosm experiments showed lower N2O emissions in the presence of biochar often correlate with a higher abundance and/or activity of N2O reducing bacteria in the presence of biochar. However, it is still unknown whether these shifts in the microbial community and/or activity is cause or effect of reduced N2O production. Biochar has the potential to change the physico-chemical environment towards conditions that favor complete denitrification, i.e. decrease the N2O/(N2O+N2) product ratio. Specifically, biochar can increase soil pH, reduce the availability of nitrate and increase the entrapment of gases, including N2O. These effects are known to decrease the N2O/(N2O+N2) ratio. In addition to the observed effects in the physio-chemical environment, we hypothesized that biochar has a direct impact on the soil microbial community. For instance, it has been shown to provide a suitable habitat to microorganisms, or facilitate electron transfer between microbe and substrates by acting as an electron shuttle or as a temporary acceptor/donor of electrons. To test this hypothesis, our experiment consisted of a microbial community extracted from soil and cultivated under anoxic conditions. It was introduced as an inoculum into three different treatments: biochar, quartz (control with a solid) and a solid-free control in the presence of a well-defined liquid medium. To maintain consistency with respect to geochemical parameters as well as to exclude any indirect effects of biochar, the concentration of substrates (nitrate, acetate) and the pH were kept identical in all three treatments. The biochar used was previously shown to reduce soil-borne N2O emissions. The results showed that biochar promoted nitrate reduction coupled to acetate consumption leading to a faster intermediate accumulation of nitrite compared to the non-biochar treatments. Additionally, N2O intermediately accumulated in the biochar treatment. Gene copy numbers from quantitative polymerase chain reaction combined with optical density measurements suggested that microbes were attached to the biochar surface instead of being suspended in the liquid. This association of microbial cells with biochar's surface might result in expedited consumption of acetate and nitrate. Since similar effects were not observed in the treatment containing quartz, they were concluded to be specific to biochar. These results can be put forth as the first evidence for a direct impact of biochar on microbial denitrification. Overall, our study highlights the need to take a detailed look at biochar's direct effect on the activity of the soil microbial community when designing biochars that target N2O mitigation.

Effective sorption of atrazine by biochar colloids and residues derived from different pyrolysis temperatures.

PubMed

Yang, Fan; Gao, Yan; Sun, Lili; Zhang, Shuaishuai; Li, Jiaojiao; Zhang, Ying

2018-04-26

Biochar has attracted much attention, which owns many environmental and agronomic benefits, including carbon sequestration, improvement of soil quality, and immobilization of environmental contaminants. Biochar has been also investigated as an effective sorbent in recent publications. Generally, biochar particles can be divided into colloids and residues according to particle sizes, while understanding of adsorption capacities towards organic pollutants in each section is largely unknown, representing a critical knowledge gap in evaluations on the effectiveness of biochar for water treatment application. Scanning electron microscopy (SEM) images, X-ray diffraction (XRD), Raman spectra, Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and Brunauer-Emmett-Teller (BET) method are used to examine the structures and surface properties of biochar colloids and residues derived from corn straws prepared at different pyrolysis temperatures. Also, their roles in atrazine (a typical organic pollutant) removal are investigated by batch adsorption experiments and fitted by different kinetic and thermodynamic models, respectively. The adsorption capacities of biochar colloids are much more than those of residues, resulting from the colloids containing abundant oxygen functional groups and mineral substances, and the adsorption capacities of biochar colloids and residues increase with the increase of pyrolysis temperatures. The highest adsorption performance of 139.33 mg g -1 can be obtained in biochar colloids prepared at 700 °C, suggesting the important functions of biochar colloids in the application of atrazine removal by biochar.

Biochar immobilizes soil-borne arsenic but not cationic metals in the presence of low-molecular-weight organic acids.

PubMed

Alozie, Nneka; Heaney, Natalie; Lin, Chuxia

2018-07-15

A batch experiment was conducted to examine the effects of biochar on the behaviour of soil-borne arsenic and metals that were mobilized by three low-molecular-weight organic acids. In the presence of citric acid, oxalic acid and malic acid at a molar concentration of 0.01M, the surface of biochar was protonated, which disfavours adsorption of the cationic metals released from the soil by organic acid-driven mobilization. In contrast, the oxyanionic As species were re-immobilized by the protonated biochar effectively. Biochar could also immobilize oxyanionic Cr species but not cationic Cr species. The addition of biochar increased the level of metals in the solution due to the release of the biochar-borne metals under attack by LMWOAs via cation exchange. Biochar could also have the potential to enhance reductive dissolution of iron and manganese oxides in the soil, leading to enhanced release of trace elements bound to these oxides. The findings obtained from this study have implications for evaluating the role of biochar in immobilizing trace elements in rhizosphere. Adsorption of cationic heavy metals on biochar in the presence of LMWOAs is unlikely to be a mechanism responsible for the impeded uptake of heavy metals by plants growing in heavy metal-contaminated soils. Copyright © 2018 Elsevier B.V. All rights reserved.

Plant growth improvement mediated by nitrate capture in co-composted biochar.

PubMed

Kammann, Claudia I; Schmidt, Hans-Peter; Messerschmidt, Nicole; Linsel, Sebastian; Steffens, Diedrich; Müller, Christoph; Koyro, Hans-Werner; Conte, Pellegrino; Joseph, Stephen; Stephen, Joseph

2015-06-09

Soil amendment with pyrogenic carbon (biochar) is discussed as strategy to improve soil fertility to enable economic plus environmental benefits. In temperate soils, however, the use of pure biochar mostly has moderately-negative to -positive yield effects. Here we demonstrate that co-composting considerably promoted biochars' positive effects, largely by nitrate (nutrient) capture and delivery. In a full-factorial growth study with Chenopodium quinoa, biomass yield increased up to 305% in a sandy-poor soil amended with 2% (w/w) co-composted biochar (BC(comp)). Conversely, addition of 2% (w/w) untreated biochar (BC(pure)) decreased the biomass to 60% of the control. Growth-promoting (BC(comp)) as well as growth-reducing (BC(pure)) effects were more pronounced at lower nutrient-supply levels. Electro-ultra filtration and sequential biochar-particle washing revealed that co-composted biochar was nutrient-enriched, particularly with the anions nitrate and phosphate. The captured nitrate in BC(comp) was (1) only partly detectable with standard methods, (2) largely protected against leaching, (3) partly plant-available, and (4) did not stimulate N2O emissions. We hypothesize that surface ageing plus non-conventional ion-water bonding in micro- and nano-pores promoted nitrate capture in biochar particles. Amending (N-rich) bio-waste with biochar may enhance its agronomic value and reduce nutrient losses from bio-wastes and agricultural soils.

Lead sorption by biochar produced from digestates: Consequences of chemical modification and washing.

PubMed

Wongrod, Suchanya; Simon, Stéphane; Guibaud, Gilles; Lens, Piet N L; Pechaud, Yoan; Huguenot, David; van Hullebusch, Eric D

2018-08-01

The main objectives of this work are to investigate the consequences of different chemical treatments (i.e. potassium hydroxide (KOH) and hydrogen peroxide (H 2 O 2 )) and the effect of biochar washing on the Pb sorption capacity. Biochars derived from sewage sludge digestate and the organic fraction of municipal solid waste digestate were separately modified with 2 M KOH or 10% H 2 O 2 followed by semi-continuous or continuous washing with ultrapure water using batch or a column reactor, respectively. The results showed that the Pb adsorption capacity could be enhanced by chemical treatment of sludge-based biochar. Indeed, for municipal solid waste biochar, the Pb maximum sorption capacity was improved from 73 mg g -1 for unmodified biochar to 90 mg g -1 and 106 mg g -1 after H 2 O 2 and KOH treatment, respectively. In the case of sewage sludge biochar, it increased from 6.5 mg g -1 (unmodified biochar) to 25 mg g -1 for H 2 O 2 treatment. The sorption capacity was not determined after KOH treatment, since the Langmuir model did not fit the experimental data. The study also highlights that insufficient washing after KOH treatment can strongly hinder Pb sorption due to the release of organic matter from the modified biochar. This organic matter may interact in solution with Pb, resulting in an inhibition of its sorption onto the biochar surface. Continuous column-washing of modified biochars was able to correct this issue, highlighting the importance of implementing a proper treated biochar washing procedure. Copyright © 2018 Elsevier Ltd. All rights reserved.

Plant growth improvement mediated by nitrate capture in co-composted biochar

PubMed Central

Kammann, Claudia I.; Schmidt, Hans-Peter; Messerschmidt, Nicole; Linsel, Sebastian; Steffens, Diedrich; Müller, Christoph; Koyro, Hans-Werner; Conte, Pellegrino; Stephen, Joseph

2015-01-01

Soil amendment with pyrogenic carbon (biochar) is discussed as strategy to improve soil fertility to enable economic plus environmental benefits. In temperate soils, however, the use of pure biochar mostly has moderately-negative to -positive yield effects. Here we demonstrate that co-composting considerably promoted biochars’ positive effects, largely by nitrate (nutrient) capture and delivery. In a full-factorial growth study with Chenopodium quinoa, biomass yield increased up to 305% in a sandy-poor soil amended with 2% (w/w) co-composted biochar (BCcomp). Conversely, addition of 2% (w/w) untreated biochar (BCpure) decreased the biomass to 60% of the control. Growth-promoting (BCcomp) as well as growth-reducing (BCpure) effects were more pronounced at lower nutrient-supply levels. Electro-ultra filtration and sequential biochar-particle washing revealed that co-composted biochar was nutrient-enriched, particularly with the anions nitrate and phosphate. The captured nitrate in BCcomp was (1) only partly detectable with standard methods, (2) largely protected against leaching, (3) partly plant-available, and (4) did not stimulate N2O emissions. We hypothesize that surface ageing plus non-conventional ion-water bonding in micro- and nano-pores promoted nitrate capture in biochar particles. Amending (N-rich) bio-waste with biochar may enhance its agronomic value and reduce nutrient losses from bio-wastes and agricultural soils. PMID:26057083

Plant growth improvement mediated by nitrate capture in co-composted biochar

NASA Astrophysics Data System (ADS)

Kammann, Claudia I.; Schmidt, Hans-Peter; Messerschmidt, Nicole; Linsel, Sebastian; Steffens, Diedrich; Müller, Christoph; Koyro, Hans-Werner; Conte, Pellegrino; Stephen, Joseph

2015-06-01

Soil amendment with pyrogenic carbon (biochar) is discussed as strategy to improve soil fertility to enable economic plus environmental benefits. In temperate soils, however, the use of pure biochar mostly has moderately-negative to -positive yield effects. Here we demonstrate that co-composting considerably promoted biochars’ positive effects, largely by nitrate (nutrient) capture and delivery. In a full-factorial growth study with Chenopodium quinoa, biomass yield increased up to 305% in a sandy-poor soil amended with 2% (w/w) co-composted biochar (BCcomp). Conversely, addition of 2% (w/w) untreated biochar (BCpure) decreased the biomass to 60% of the control. Growth-promoting (BCcomp) as well as growth-reducing (BCpure) effects were more pronounced at lower nutrient-supply levels. Electro-ultra filtration and sequential biochar-particle washing revealed that co-composted biochar was nutrient-enriched, particularly with the anions nitrate and phosphate. The captured nitrate in BCcomp was (1) only partly detectable with standard methods, (2) largely protected against leaching, (3) partly plant-available, and (4) did not stimulate N2O emissions. We hypothesize that surface ageing plus non-conventional ion-water bonding in micro- and nano-pores promoted nitrate capture in biochar particles. Amending (N-rich) bio-waste with biochar may enhance its agronomic value and reduce nutrient losses from bio-wastes and agricultural soils.

Effects of pyrolysis temperature on soybean stover- and peanut shell-derived biochar properties and TCE adsorption in water.

PubMed

Ahmad, Mahtab; Lee, Sang Soo; Dou, Xiaomin; Mohan, Dinesh; Sung, Jwa-Kyung; Yang, Jae E; Ok, Yong Sik

2012-08-01

Conversion of crop residues into biochars (BCs) via pyrolysis is beneficial to environment compared to their direct combustion in agricultural field. Biochars developed from soybean stover at 300 and 700 °C (S-BC300 and S-BC700, respectively) and peanut shells at 300 and 700 °C (P-BC300 and P-BC700, respectively) were used for the removal of trichloroethylene (TCE) from water. Batch adsorption experiments showed that the TCE adsorption was strongly dependent on the BCs properties. Linear relationships were obtained between sorption parameters (K(M) and S(M)) and molar elemental ratios as well as surface area of the BCs. The high adsorption capacity of BCs produced at 700 °C was attributed to their high aromaticity and low polarity. The efficacy of S-BC700 and P-BC700 for removing TCE from water was comparable to that of activated carbon (AC). Pyrolysis temperature influencing the BC properties was a critical factor to assess the removal efficiency of TCE from water. Copyright © 2012 Elsevier Ltd. All rights reserved.

Production of bio-based phenolic resin and activated carbon from bio-oil and biochar derived from fast pyrolysis of palm kernel shells.

PubMed

Choi, Gyung-Goo; Oh, Seung-Jin; Lee, Soon-Jang; Kim, Joo-Sik

2015-02-01

A fraction of palm kernel shells (PKS) was pyrolyzed in a fluidized bed reactor. The experiments were performed in a temperature range of 479-555 °C to produce bio-oil, biochar, and gas. All the bio-oils were analyzed quantitatively and qualitatively by GC-FID and GC-MS. The maximum content of phenolic compounds in the bio-oil was 24.8 wt.% at ∼500 °C. The maximum phenol content in the bio-oil, as determined by the external standard method, was 8.1 wt.%. A bio-oil derived from the pyrolysis of PKS was used in the synthesis of phenolic resin, showing that the bio-oil could substitute for fossil phenol up to 25 wt.%. The biochar was activated using CO2 at a final activation temperature of 900 °C with different activation time (1-3 h) to produce activated carbon. Activated carbons produced were microporous, and the maximum surface area of the activated carbons produced was 807 m(2)/g. Copyright © 2014 Elsevier Ltd. All rights reserved.

Water clusters contributed to molecular interactions of ionizable organic pollutants with aromatized biochar via π-PAHB: Sorption experiments and DFT calculations.

PubMed

Zhang, Kun; Chen, Baoliang; Mao, Jiefei; Zhu, Lizhong; Xing, Baoshan

2018-05-08

Molecular interactions between biochars and ionizable organic pollutants (IOPs) are of great concern in natural environments, however the role of water clusters on the biochar surface remain unclear. The pH-dependent adsorption of aniline, phenol, 2-chlorophenol, 3-chlorophenol, 4-chlorophenol, 4-methylphenol and 4-nitrophenol onto bamboo wood derived biochar (BW700) as a model was conducted to identify conventional and novel interaction mechanisms between aromatized surface and IOPs. The dissociation constant (pK a,surface ) of surface functional groups of BW700 was characterized by acid-base titration and Zeta potential measurements. The pH-dependent adsorption behavior depended on the pK a,IOP of IOPs and also related to the pK a,surface of biochar surface. An obvious peak of adsorption coefficients (K d ) in the range of solution pH was shaped at pH peak  = (pK a,IOP  + pK a,surface )/2, which cannot be well explained by the conventional mechanisms such as hydrophobic effects, π-π interaction, electrostatic attractions, and hydrogen-binding. The contribution of ice-like adlayer (water clusters) on aromatic surface as H-acceptors is proposed for the first time to the adsorption peak of IOP as H-donors at pH peak . Density functional theory (DFT) calculations provided a possible structure of the complex combined with ice-like adlayer and aromatic substrate of BW700, and indicated that the adsorbing peak resulted from the multiple π-bond and polarization assisted H-bond (π-PAHB) interactions. Three distinct properties of π-PAHB were given, based on multiple π-bond, hydrophobicity-dependence and pH sensitivity. This novel mechanism extends the definition of H-bonds for better understanding the molecular interactions of IOP with carbonaceous materials and their environmental fate. Copyright © 2018 Elsevier Ltd. All rights reserved.

Sulfur-modified rice husk biochar: A green method for the remediation of mercury contaminated soil.

PubMed

O'Connor, David; Peng, Tianyue; Li, Guanghe; Wang, Shuxiao; Duan, Lei; Mulder, Jan; Cornelissen, Gerard; Cheng, Zhenglin; Yang, Shengmao; Hou, Deyi

2018-04-15

Mercury (Hg) contamination of surface soils has increased by ~86Giga grams due to anthropogenic activities. There is an urgent need to find new, effective and preferably 'green' remediation technologies to protect human health and the environment. Sulfur-modification of sorbents can greatly enhance Hg sorption capacity - by forming low solubility HgS (cinnabar). However, S-modified sorbents are not considered suitable for soil remediation due to the economic cost and secondary environmental impacts of sorbents such as granulated activated carbon (GAC), and the toxicity of S-modifiers such as thiol compounds. It was previously found that if biochar is used as an alternative to GAC then the overall environmental impact can be significantly reduced. However, due to a lack of experimental evidence, the practicality of S-modified biochar remains uncertain. The present study was undertaken to provide a proof-of-concept for the 'green' remediation of Hg contaminated soils with rice husk biochar modified with non-toxic elemental S. It was found that the S modification process increased the biochar S content from 0.2% to 13.04% via surface deposition or volume pore filling. This increased the biochar's Hg 2+ adsorptive capacity (Q max ) by ~73%, to 67.11mg/g. To assess the performance of S-modified rice husk biochar for soil remediation it was applied to a high 1000mg/kg Hg 2+ contaminated soil. Treatment dosages of 1%, 2% and 5% (dry wt.) were found to reduce freely available Hg in TCLP (toxicity characterization leaching procedure) leachates by 95.4%, 97.4% and 99.3%, respectively, compared to untreated soil. In comparison, unmodified rice husk biochar reduced Hg concentrations by 94.9%, 94.9% and 95.2% when applied at the same treatment dosage rates, respectively. This study has revealed that S-modified rice husk biochar has potential to stabilize Hg as a 'green' method for the remediation of contaminated soils. Copyright © 2017 Elsevier B.V. All rights reserved.

Hardwood biochar and manure co-application to a calcareous soil.

PubMed

Ippolito, J A; Stromberger, M E; Lentz, R D; Dungan, R S

2016-01-01

Biochar may affect the mineralization rate of labile organic C sources such as manures via microbial community shifts, and subsequently affect nutrient release. In order to ascertain the positive or negative priming effect of biochar on manure, dairy manure (2% by wt.) and a hardwood-based, fast pyrolysis biochar were applied (0%, 1%, 2%, and 10% by wt.) to a calcareous soil. Destructive sampling occurred at 1, 2, 3, 4, 6 and 12 months to monitor for changes in soil chemistry, water content, microbial respiration, bacterial populations, and microbial community structure. Overall results showed that increasing biochar application rate improved the soil water content, which may be beneficial in limited irrigation or rainfall areas. Biochar application increased soil organic C content and plant-available Fe and Mn, while a synergistic biochar-manure effect increased plant-available Zn. Compared to the other rates, the 10% biochar application lowered concentrations of NO3-N; effects appeared masked at lower biochar rates due to manure application. Over time, soil NO3-N increased likely due to manure N mineralization, yet soil NO3-N in the 10% biochar rate remained lower as compared to other treatments. In the presence of manure, only the 10% biochar application caused subtle microbial community structure shifts by increasing the relative amounts of two fatty acids associated with Gram-negative bacteria and decreasing Gram-positive bacterial fatty acids, each by ∼1%. Our previous findings with biochar alone suggested an overall negative priming effect with increasing biochar application rates, yet when co-applied with manure the negative priming effect was eliminated. Published by Elsevier Ltd.

Biochar amendment immobilizes lead in rice paddy soils and reduces its phytoavailability

PubMed Central

Li, Honghong; Liu, Yuting; Chen, Yanhui; Wang, Shanli; Wang, Mingkuang; Xie, Tuanhui; Wang, Guo

2016-01-01

This study aimed to determine effects of rice straw biochar on Pb sequestration in a soil-rice system. Pot experiments were conducted with rice plants in Pb-contaminated paddy soils that had been amended with 0, 2.5, and 5% (w/w) biochar. Compared to the control treatment, amendment with 5% biochar resulted in 54 and 94% decreases in the acid soluble and CaCl2-extractable Pb, respectively, in soils containing rice plants at the maturity stage. The amount of Fe-plaque on root surfaces and the Pb concentrations of the Fe-plaque were also reduced in biochar amended soils. Furthermore, lead species in rice roots were determined using Pb L3-edge X-ray absorption near edge structure (XANES), and although Pb-ferrihydrite complexes dominated Pb inventories, increasing amounts of organic complexes like Pb-pectins and Pb-cysteine were found in roots from the 5% biochar treatments. Such organic complexes might impede Pb translocation from root to shoot and subsequently reduce Pb accumulation in rice with biochar amendment. PMID:27530495

Silver removal from aqueous solution by biochar produced from biosolids via microwave pyrolysis.

PubMed

Antunes, Elsa; Jacob, Mohan V; Brodie, Graham; Schneider, Philip A

2017-12-01

The contamination of water with silver has increased due to the widespread applications of products with silver employed as antimicrobial agent. Adsorption is a cost-effective method for silver removal from aqueous solution. In this study biochar, produced from the microwave assisted pyrolysis of biosolids, was used for silver removal from an aqueous solution. The adsorption kinetics, isotherms and thermodynamics were investigated to better understand the silver removal process by biochar. X-ray diffraction results demonstrated that silver removal was a combination two consecutive mechanisms, reduction and physical adsorption. The Langmuir model fitted the experimental data well, showing that silver removal was predominantly a surface mechanism. The thermodynamic investigation demonstrated that silver removal by biochar was an exothermic process. The final nanocomposite Ag-biochar (biochar plus silver) was used for methylene blue adsorption and photodegradation. This study showed the potential of using biochar produced from biosolids for silver removal as a promising solution to mitigate water pollution and an environmentally sustainable approach for biosolids management and re-use. Copyright © 2017 Elsevier Ltd. All rights reserved.

Engineered carbon (biochar) prepared by direct pyrolysis of Mg-accumulated tomato tissues: characterization and phosphate removal potential.

PubMed

Yao, Ying; Gao, Bin; Chen, Jianjun; Zhang, Ming; Inyang, Mandu; Li, Yuncong; Alva, Ashok; Yang, Liuyan

2013-06-01

An innovative method was developed to produce engineered biochar from magnesium (Mg) enriched tomato tissues through slow pyrolysis in a N2 environment. Tomato plants treated with 25mM Mg accumulated much higher level of Mg in tissue, indicating Mg can be substantially enriched in tomato plants, and pyrolysis process further concentrated Mg in the engineered biochar (8.8% Mg). The resulting Mg-biochar composites (MgEC) showed better sorption ability to phosphate (P) in aqueous solutions compared to the other four tomato leaves biochars. Statistical analysis showed a strong and significant correlation between P removal rate and biochar Mg content (R(2)=0.78, and p<0.001), indicating the enriched Mg in the engineered biochar is the main factor controlling its P removal ability. SEM-EDX, XRD and XPS analyses showed that nanoscale Mg(OH)2 and MgO particles were presented on the surface of MgEC, which serve as the main adsorption sites for aqueous P. Copyright © 2013 Elsevier Ltd. All rights reserved.

Biochar has no effect on soil respiration across Chinese agricultural soils.

PubMed

Liu, Xiaoyu; Zheng, Jufeng; Zhang, Dengxiao; Cheng, Kun; Zhou, Huimin; Zhang, Afeng; Li, Lianqing; Joseph, Stephen; Smith, Pete; Crowley, David; Kuzyakov, Yakov; Pan, Genxing

2016-06-01

Biochar addition to soil has been widely accepted as an option to enhance soil carbon sequestration by introducing recalcitrant organic matter. However, it remains unclear whether biochar will negate the net carbon accumulation by increasing carbon loss through CO2 efflux from soil (soil respiration). The objectives of this study were to address: 1) whether biochar addition increases soil respiration; and whether biochar application rate and biochar type (feedstock and pyrolyzing system) affect soil respiration. Two series of field experiments were carried out at 8 sites representing the main crop production areas in China. In experiment 1, a single type of wheat straw biochar was amended at rates of 0, 20 and 40 tha(-1) in four rice paddies and three dry croplands. In experiment 2, four types of biochar (varying in feedstock and pyrolyzing system) were amended at rates of 0 and 20 tha(-1) in a rice paddy under rice-wheat rotation. Results showed that biochar addition had no effect on CO2 efflux from soils consistently across sites, although it increased topsoil organic carbon stock by 38% on average. Meanwhile, CO2 efflux from soils amended with 40 t of biochar did not significantly higher than soils amended with 20 t of biochar. While the biochars used in Experiment 2 had different carbon pools and physico-chemical properties, they had no effect on soil CO2 efflux. The soil CO2 efflux following biochar addition could be hardly explained by the changes in soil physic-chemical properties and in soil microbial biomass. Thus, we argue that biochar will not negate the net carbon accumulation by increasing carbon loss through CO2 efflux in agricultural soils. Copyright © 2016. Published by Elsevier B.V.

Optimization of Fe2+ Removal from Coal Mine Wastewater using Activated Biochar of Colocasia esculenta.

PubMed

Banerjee, Soumya; LaminKa-Ot, Augustine; Joshi, S R; Mandal, Tamal; Halder, Gopinath

2017-09-01

  The present study investigates the sorptive removal of Fe2+ from simulated coal mine waste water using steam activated biochar (SABC) developed from the roots of Colocasia esculenta. The process was optimized by response surface methodology (RSM) under the influence of pH, temperature, adsorbent dosage and contact time at a constant shaking speed of 180 rpm with an initial concentration of 3 mg/L. The uptake performance of the biosorbent was assessed following a 24 full factorial experimental matrix developed by central composite design approach. Adsorbent was characterised by SEM, EDAX, XRD and B.E.T surface area analyzer. Maximum removal of 72.96% of Fe2+ was observed at pH 7.75, temperature 37.5 °C, adsorbent dosage 1.5 g/L for a time period of 180 mins. The study suggested that SABC prepared from roots of Colocasia esculenta could be used as an efficient and cost effective sorbent for removal of Fe2+ from coal mine wastewater.

Sorption interactions of heavy metals with biochar in soil remediation studies

NASA Astrophysics Data System (ADS)

Fristak, Vladimir; Friesl-Hanl, Wolfgang; Wawra, Anna; Soja, Gerhard

2015-04-01

The search for new materials in soil remediation applications has led to new conversion technologies such as carbonization and pyrolysis. Biochar represents the pyrolytic product of different biomass input materials processed at 350-1000°C and anoxic conditions. The pyrolysis temperature and feedstock have a considerable influence on the quality of the charred product and also its main physico-chemical properties. Biochar as porous material with large specific surface and C-stability is utilized in various environmental and agricultural technologies. Carbon sequestration, increase of soil water-holding capacity and pH as well as sorption of different xenobiotics present only a fraction of the multitude of biochar application possibilities. Heavy metals as potential sources of ecotoxicological risks are characterized by their non-degradability and the potential transfer into the food chain. Carbonaceous materials have been used for a long time as sorbents for heavy metals and organic contaminants in soil and water technologies. The similarity of biochar with activated carbon predetermines this material as remediation tool which plays an important role in heavy metal immobilization and retention with a parallel reduction in the risk of ground water and food crop contamination. In all this processes the element-specific sorption behaviour of biochar creates new conditions for pollutant binding. Sorption interaction and separation of contaminants from soil solution or waste effluent can be affected by wide-ranging parameters. In detail, our study was based on batch-sorption comparisons of two biochars produced from wood chips and green waste residues. We observed that sorption efficiency of biochar for model bivalent heavy metals (Cd, Zn, Cu) can be influenced by equilibrium parameters such as pH, contact time, initial concentration of metal in reaction solutions, presence of surfactants and chemical modification by acid hydrolysis, esterification and methylation. The study of sorption mechanisms showed differences in the sorption of the targeted heavy metals in relation to the contribution of ion-exchange and precipitation processes. We confirmed the effectivity of physico-chemical artificial aging on sorption capacity of biochar in terms of changes in surface structure. Based on these results, the application potential of biochar as sorption material for stabilizing heavy metals in soils is discussed.

TiO2 supported on reed straw biochar as an adsorptive and photocatalytic composite for the efficient degradation of sulfamethoxazole in aqueous matrices.

PubMed

Zhang, Hanyu; Wang, Zhaowei; Li, Ruining; Guo, Jialei; Li, Yan; Zhu, Junmin; Xie, Xiaoyun

2017-10-01

Heterogeneous photocatalysis namely titanium dioxide supported on reed straw biochar (acid pre-treated) (TiO 2 /pBC) was synthesized by sol-gel method. The morphology, surface area and structure of TiO 2 /pBC were characterized by scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET), and X-ray diffraction (XRD). Low calcination condition maintained the structure of biochar completely and prevented the agglomeration of TiO 2 particles. Due to the combination of adsorption and photocatalysis, TiO 2 /pBC performed higher removal efficiency of sulfamethoxazole (SMX) than pure TiO 2 powder under UV light irradiation. The photocatalytic degradation (PCD) of SMX was also studied with the water collected from the Yellow River. Three high concentration inorganic anions (Cl - , NO 3 - , SO 4 2- ) of the river exerted certain degree of detrimental effects on the contaminant degradation. TiO 2 /pBC showed stable photocatalytic activity after five sequential PCD cycles. The biochar was able to promote further PCD on TiO 2 by adsorbing SMX and intermediates thereby prolonging the separation lifetime of electrons (e - ) and valence band hole (h + ). The transformation intermediates of SMX were identified and three possible degradation reactions of hydroxylation, opening of isoxazole ring and cleavage of SN bond might occur during the PCD of SMX. Copyright © 2017 Elsevier Ltd. All rights reserved.

Correlations and adsorption mechanisms of aromatic compounds on biochars produced from various biomass at 700 °C.

PubMed

Yang, Kun; Jiang, Yuan; Yang, Jingjing; Lin, Daohui

2018-02-01

Knowledge of adsorption behavior of organic contaminants on high heat temperature treated biochars is essential for application of biochars as adsorbents in wastewater treatment and soil remediation. In this study, isotherms of 25 aromatic compounds adsorption on biochars pyrolyzed at 700 °C from biomass including wood chips, rice straw, bamboo chips, cellulose, lignin and chitin were investigated to establish correlations between adsorption behavior and physicochemical properties of biochars. Isotherms were well fitted by Polanyi theory-based Dubinin-Ashtakhov (DA) model with three parameters, i.e., adsorption capacity (Q 0 ) and adsorption affinity (E and b). Besides the negative correlation of Q 0 with molecular maximum cross-sectional areas (σ) of organic compounds, positive correlations of Q 0 with total pore volume (V total ) and average diameter of micropore (D) of biochars were observed, indicating that adsorption by biochars is captured by the pore-filling mechanism with molecular sieving effect in biochar pores. Linear solvation energy relationships (LSERs) of adsorption affinity (E) with solvatochromic parameters of organic compounds (i. e., α m and π ∗ ) were established, suggesting that hydrophobic effect, π-π interaction and hydrogen-bonding interaction are the main forces responsible for adsorption. The regression coefficient (π 1 ) and intercept (C) of obtained LSERs are correlated with biochar H/C and R micro , respectively, implying that biochars with higher aromaticity and more micropores have stronger π-π bonding potential and hydrophobic effect potential with aromatic molecule, respectively. However, hydrogen-bonding potential of biochars for organic molecules is not changed significantly with properties of biochars. A negative correlation of b with biochar H/C is also obtained. These correlations could be used to predict the adsorption behavior of organic compounds on high heat temperature treated biochars from various biomass for the application of biochars as sorbents and for the estimating of environmental risks of organic compounds in the present of biochars. Copyright © 2017 Elsevier Ltd. All rights reserved.

Biochar pyrolyzed at two temperatures affects Escherichia coli transport through a sandy soil.

PubMed

Bolster, Carl H; Abit, Sergio M

2012-01-01

The incorporation of biochar into soils has been proposed as a means to sequester carbon from the atmosphere. An added environmental benefit is that biochar has also been shown to increase soil retention of nutrients, heavy metals, and pesticides. The goal of this study was to evaluate whether biochar amendments affect the transport of Escherichia coli through a water-saturated soil. We looked at the transport of three E. coli isolates through 10-cm columns packed with a fine sandy soil amended with 2 or 10% (w/w) poultry litter biochar pyrolyzed at 350 or 700°C. For all three isolates, mixing the high-temperature biochar at a rate of 2% into the soil had no impact on transport behavior. When added at a rate of 10%, a reduction of five orders of magnitude in the amount of E. coli transported through the soil was observed for two of the isolates, and a 60% reduction was observed for the third isolate. Mixing the low-temperature biochar into the soil resulted in enhanced transport through the soil for two of the isolates, whereas no significant differences in transport behavior were observed between the low-temperature and high-temperature biochar amendments for one isolate. Our results show that the addition of biochar can affect the retention and transport behavior of E. coli and that biochar application rate, biochar pyrolysis temperature, and bacterial surface characteristics were important factors determining the transport of E. coli through our test soil. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Methodological interference of biochar in the determination of extracellular enzyme activities in composting samples

NASA Astrophysics Data System (ADS)

Jindo, K.; Matsumoto, K.; García Izquierdo, C.; Sonoki, T.; Sanchez-Monedero, M. A.

2014-07-01

Biochar application has received increasing attention as a means to trap recalcitrant carbon and enhance soil fertility. Hydrolytic enzymatic assays, such as β-glucosidase and phosphatase activities, are used for the assessment of soil quality and composting process, which are based on use of p-nitrophenol (PNP) derivatives as substrate. However, sorption capacity of biochar can interfere with colorimetric determination of the hydrolysed PNP, either by the sorption of the substrate or the reaction product of hydrolysis into biochar surface. The aim of the present work is to study the biochar sorption capacity for PNP in biochar-blended composting mixtures in order to assess its impact on the estimation of the colorimetric-based enzymatic assays. A retention test was conducted by adding a solution of known amounts of PNP in universal buffer solution (pH = 5, 6.5 and 11, corresponding to the β-glucosidase, acid and alkaline phosphatase activity assays, respectively), in samples taken at the initial stage and after maturation stage from four different composting piles (two manure composting piles; PM: poultry manure, CM: cow manure and two other similar piles containing 10% of additional biochar (PM + B, CM + B)). The results show that biochar-blended composts (PM + B, CM + B) generally exhibited low enzymatic activities, compared to manure compost without biochar (PM, CM). In terms of the difference between the initial and maturation stage of composting process, the PNP retention in biochar was shown higher at maturation stage, caused most probably by an enlarged proportion of biochar inside compost mixture after the selective degradation of easily decomposable organic matter. TThe retention of PNP on biochar was influenced by pH dependency of sorption capacity of biochar and/or PNP solubility, since PNP was more efficiently retained by biochar at low pH values (5 and 6.5) than at high pH values (11).

Activated carbon and biochar from agricultural by-products in the adorption of Cd, Pb and Zn under laboratory conditions

NASA Astrophysics Data System (ADS)

Coscione, Aline; Zini, Barbara

2015-04-01

The immobilization of inorganic contaminants by using biochar in soils has played an increasingly important role and it is seen as an attractive alternative for the remediation of heavy metals. Although, the production of activated carbon (CA) from agricultural by-products has received special attention, the activation of the the organic source has been studied in order to increase its porposity, surface area and chemical polarity, resulting in higher adsorption of metals. Therefore, this study aimed to evaluate the effectiveness of BC and CA samples, obtained from a eucalyptus husks and cane sugar bagasse after activation with 20% phosphoric acid and pyrolyzed at 450oC in the retention of Zn, Cd and Pb using contaminated individual solutions. The experiment was performed using samples of activated carbon of eucalyptus husk (CCA), eucalyptus husk biochar (BC), activated carbon of sugar cane bagasse (CBA) and sugar cane bagasse biochar (BB), treated with Zn, Cd (range of tested solution from 0.1 up to 12 mmol L-1) and Pb (from 0.1 up 50 mmol L-1) and the adjustemento of Langmuir adsorption isotherms. Samples obtained from bagasse presented higher adsoprtion of the metals tested then eucalyptus. Also the activation process had not the expected effect on either eucalyptus and bagasse samples The maxmum adsorption capacyty of samples were as follws, in mmol g-1: for Cd - 0.36 for BC; 0.32 for CCA; 0.40 for BB; 0.31 for CBA. For Zn- 0.14 for BC; no adsorbed by CCA; 0.35 5 for BB; 0.06 for CBA. For Pb - 1.24 for BC; 0.40 for CCA; 0,45 for BB; 0,03 for CBA. However, it was also observed that due to the activation with phosphoric acid, the pH of the activated carbon (CCA and CBA) were 2.4 and 2.5 in comparison with the biochars not activated (BC and BB) 9.7 and 7.0 respectively. Thus, it is yet not possible to state if the calculate capacity is due exclusively to the complexation of chemical groups in the surface of samples or to which extent there is a contribution of precipitation caused by the basic pH (non-activated) biochar samples, as shown for Zn and Pb.

Biochar-attenuated desorption of heavy metals in small arms range soils

USDA-ARS?s Scientific Manuscript database

Stabilization (capping/solidification) and dilution (e.g., washing, chelate-assisted phytoremediation) represent non-removal and removal remediation technologies for heavy metal contaminated soils. Biochar is stable in soil, and contains carboxyl and other surface ligands; these properties are usef...

Why biochar application did not improve the soil water retention of a sandy soil: An investigation into the underlying mechanisms.

NASA Astrophysics Data System (ADS)

Jeffery, Simon; Meinders, Marcel B. J.; Stoof, Cathelijne; Bezemer, T. Martijn; vande Voorde, Tess F. J.; Mommer, Liesje; Willem van Groenigen, Jan

2015-04-01

Biochar application to soil is currently being widely touted as a means to improve soil quality and to enhance the provision of numerous ecosystem services, including water storage, in soils. However, evidence for hydrological effects in the primary literature remain inconclusive with contradictory effects reported. The mechanisms behind such contradictory results are not yet elucidated. As such we aimed to investigate the effects of biochar on soil water retention and infiltration, as well as the underlying mechanisms. To do so we set up two field experiments with biochar produced from herbaceous feedstock through slow pyrolysis at two temperatures (400°C and 600°C). In the first experiment both biochars were applied at a rate of 10 t ha-1 to separate plots in a sandy soil in a North European grassland. In a separate experiment, the biochar produced at 400°C was applied to a different set of plots in the same grassland at rates equivalent to 1, 5, 20 and 50 t ha-1. Soils from these experiments were analysed for soil water retention and infiltration rate as well as aggregate stability and other soil physical parameters. The pore structure of the biochar was fully characterised using X-ray computed micro-tomography (XRT) and hydrophobicity determined using contact angle measurements. There were no significant effects of biochar application on soil water retention, field saturated conductivity or aggregate stability in either experiment. XRT analysis of the biochars confirmed that the biochars were highly porous, with 48% and 57% porosity for the 400°C and 600°C biochars, respectively. More than 99% of internal pores of the biochar particles were connected to the surface, suggesting a potential role for biochars in improving soil water retention. However, the biochars were highly hydrophobic as demonstrated by the high contact angles when water was applied. We suggest that this hydrophobicity greatly diminished water infiltration into the biochar particles, prohibiting an effect on soil water retention. Our results indicate that, in addition to characterizing pore space, biochars should be analysed for hydrophobicity when assessing their capacity for improving soil physical properties.

Effect of humic acid (HA) on sulfonamide sorption by biochars.

PubMed

Lian, Fei; Sun, Binbin; Chen, Xi; Zhu, Lingyan; Liu, Zhongqi; Xing, Baoshan

2015-09-01

Effect of quantity and fractionation of loaded humic acid (HA) on biochar sorption for sulfonamides was investigated. The HA was applied in two different modes, i.e. pre-coating and co-introduction with sorbate. In pre-coating mode, the polar fractions of HA tended to interact with low-temperature biochars via H-bonding, while the hydrophobic fractions were likely to be adsorbed by high-temperature biochars through hydrophobic and π-π interactions, leading to different composition and structure of the HA adlayers. The influences of HA fractionation on biochar sorption for sulfonamides varied significantly, depending on the nature of interaction between HA fraction and sorbate. Meanwhile, co-introduction of HA with sulfonamides revealed that the effect of HA on sulfonamide sorption was also dependent on HA concentration. These findings suggest that the amount and fractionation of adsorbed HA are tailored by the surface properties of underlying biochars, which differently affect the sorption for organic contaminants. Copyright © 2015 Elsevier Ltd. All rights reserved.

Crop residue decomposition in Minnesota biochar-amended plots

NASA Astrophysics Data System (ADS)

Weyers, S. L.; Spokas, K. A.

2014-06-01

Impacts of biochar application at laboratory scales are routinely studied, but impacts of biochar application on decomposition of crop residues at field scales have not been widely addressed. The priming or hindrance of crop residue decomposition could have a cascading impact on soil processes, particularly those influencing nutrient availability. Our objectives were to evaluate biochar effects on field decomposition of crop residue, using plots that were amended with biochars made from different plant-based feedstocks and pyrolysis platforms in the fall of 2008. Litterbags containing wheat straw material were buried in July of 2011 below the soil surface in a continuous-corn cropped field in plots that had received one of seven different biochar amendments or a uncharred wood-pellet amendment 2.5 yr prior to start of this study. Litterbags were collected over the course of 14 weeks. Microbial biomass was assessed in treatment plots the previous fall. Though first-order decomposition rate constants were positively correlated to microbial biomass, neither parameter was statistically affected by biochar or wood-pellet treatments. The findings indicated only a residual of potentially positive and negative initial impacts of biochars on residue decomposition, which fit in line with established feedstock and pyrolysis influences. Overall, these findings indicate that no significant alteration in the microbial dynamics of the soil decomposer communities occurred as a consequence of the application of plant-based biochars evaluated here.

Biochar lowers ammonia emission and improves nitrogen retention in poultry litter composting.

PubMed

Agyarko-Mintah, Eunice; Cowie, Annette; Van Zwieten, Lukas; Singh, Bhupinder Pal; Smillie, Robert; Harden, Steven; Fornasier, Flavio

2017-03-01

The poultry industry produces abundant quantities of nutrient-rich litter, much of which is composted before use as a soil amendment. However, a large proportion of nitrogen (N) in poultry litter is lost via volatilisation during composting, with negative environmental and economic consequences. This study examined the effect of incorporating biochar during composting of poultry litter on ammonia (NH 3 ) volatilisation and N retention. Biochars produced at 550°C from greenwaste (GWB) and poultry litter (PLB) feedstocks were co-composted with a mixture of raw poultry litter and sugarcane straw [carbon (C):N ratio 10:1] in compost bins. Ammonia emissions accounted for 17% of the total N (TN) lost from the control and 12-14% from the biochar-amended compost. The TN emitted as NH 3 , as a percentage of initial TN, was significantly lower (P<0.05) i.e. by 60% and 55% in the compost amended with GWB and PLB, respectively, relative to the control. The proportion of N retained in the finished compost, as a percentage of initial TN, was 84%, 78% and 67% for the GWB, PLB and nil biochar control, respectively. Lower concentration of dissolved organic C (DOC) together with higher activity of beta-glucosidase and leucine-aminopeptidase were found in the GWB-amended compost (cf. control). It is hypothesized that lower NH 3 emission in the GWB-amended compost was caused not just by the higher surface area of this biochar but could also be related to greater incorporation of ammonium (NH 4 + ) in organic compounds during microbial utilisation of DOC. Furthermore, the GWB-amended compost retained more NH 4 + at the end of composting than the PLB-amended compost. Results showed that addition of biochar, especially GWB, generated multiple benefits in composting of poultry litter: decrease of NH 3 volatilisation, decrease in NH 3 toxicity towards microorganisms, and improved N retention, thus enhancing the fertiliser value of the composted litter. It is suggested that the latter benefit is linked to a beneficial modification of the microbial environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Pb(II), Cr(VI) and atrazine sorption behavior on sludge-derived biochar: role of humic acids.

PubMed

Zhou, Fengsa; Wang, Hong; Fang, Sheng'en; Zhang, Weihua; Qiu, Rongliang

2015-10-01

Pyrolyzing municipal wastewater treatment sludge into biochar can be a promising sludge disposal approach, especially as the produced sludge-derived biochar (SDBC) is found to be an excellent sorbent for heavy metals and atrazine. The aim of this study was to investigate how and why the coexisting humic acids influence the sorption capacity, kinetic, and binding of these contaminants on SDBC surface. Results showed humic acids enhanced Pb(II)/Cr(VI) sorption binding, and increased the corresponding Pb(II) Langmuir sorption capacity at pH 5.0 from 197 to 233 μmol g(-1), and from 688 to 738 μmol g(-1) for Cr(VI) at pH 2.0. It can be mainly attributed to the sorbed humic acids, whose active functional groups can offer the additional sites to form stronger inner-sphere complexes with Pb(2+), and supply more reducing agent to facilitate the transformation of Cr(VI) to Cr(III). However, humic acids reduced the atrazine adsorption Freundlich constant from 1.085 to 0.616 μmol g(-1). The pore blockage, confirmed by the decreased BET-specific surface area, as well as the more hydrophilic surface with more sorbed water molecules may be the main reasons for that suppression. Therefore, the coexisting humic acids may affect heavy metal stabilization or pesticide immobilization during SDBC application to contaminated water or soils, and its role thus should be considered especially when organic residues are also added significantly to increase the humic acid content there.

Thermal treatment and leaching of biochar alleviates plant growth inhibition from mobile organic compounds

PubMed Central

Sackett, Tara E.; Thomas, Sean C.

2016-01-01

Recent meta-analyses of plant responses to biochar boast positive average effects of between 10 and 40%. Plant responses, however, vary greatly across systems, and null or negative biochar effects are increasingly reported. The mechanisms responsible for such responses remain unclear. In a glasshouse experiment we tested the effects of three forestry residue wood biochars, applied at five dosages (0, 5, 10, 20, and 50 t/ha) to a temperate forest drystic cambisol as direct surface applications and as complete soil mixes on the herbaceous pioneers Lolium multiflorum and Trifolium repens. Null and negative effects of biochar on growth were found in most cases. One potential cause for null and negative plant responses to biochar is plant exposure to mobile compounds produced during pyrolysis that leach or evolve following additions of biochars to soil. In a second glasshouse experiment we examined the effects of simple leaching and heating techniques to ameliorate potentially phytotoxic effects of volatile and leachable compounds released from biochar. We used Solid Phase Microextraction (SPME)–gas chromatography–mass spectrometry (GC-MS) to qualitatively describe organic compounds in both biochar (through headspace extraction), and in the water leachates (through direct injection). Convection heating and water leaching of biochar prior to application alleviated growth inhibition. Additionally, growth was inhibited when filtrate from water-leached biochar was applied following germination. SPME-GC-MS detected primarily short-chained carboxylic acids and phenolics in both the leachates and solid chars, with relatively high concentrations of several known phytotoxic compounds including acetic acid, butyric acid, 2,4-di-tert-butylphenol and benzoic acid. We speculate that variable plant responses to phytotoxic organic compounds leached from biochars may largely explain negative plant growth responses and also account for strongly species-specific patterns of plant responses to biochar amendments in short-term experiments. PMID:27635349

Antagonistic effects of humic acid and iron oxyhydroxide grain-coating on biochar nanoparticle transport in saturated sand.

PubMed

Wang, Dengjun; Zhang, Wei; Zhou, Dongmei

2013-05-21

Biochar land application may result in multiple agronomic and environmental benefits (e.g., carbon sequestration, improving soil quality, and immobilizing environmental contaminants). However, our understanding of biochar particle transport is largely unknown in natural environments with significant heterogeneity in solid (e.g., patches of iron oxyhydroxide coating) and solution chemistry (e.g., the presence of natural organic matter), which represents a critical knowledge gap in assessing the environmental impact of biochar land application. Transport and retention kinetics of nanoparticles (NPs) from wheat straw biochars produced at two pyrolysis temperatures (i.e., 350 and 550 °C) were investigated in water-saturated sand columns at environmentally relevant concentrations of dissolved humic acid (HA, 0, 1, 5, and 10 mg L(-1)) and fractional surface coverage of iron oxyhydroxide coatings on sand grains (ω, 0.16, 0.28, and 0.40). Transport of biochar NPs increased with increasing HA concentration, largely because of enhanced repulsive interaction energy between biochar NPs and sand grains. Conversely, transport of biochar NPs decreased significantly with increasing ω due to enhanced electrostatic attraction between negatively charged biochar NPs and positively charged iron oxyhydroxides. At a given ω of 0.28, biochar NPs were less retained with increasing HA concentration due to increased electrosteric repulsion between biochar NPs and sand grains. Experimental breakthrough curves and retention profiles were well described using a two-site kinetic retention model that accounted for Langmuirian blocking or random sequential adsorption at one site. Consistent with the blocking effect, the often observed flat retention profiles stemmed from decreased retention rate and/or maximum retention capacity at a higher HA concentration or smaller ω. The antagonistic effects of HA and iron oxyhydroxide grain-coating imparted on the mobility of biochar NPs suggest that biochar colloid transport potential will be dependent on competitive influences exerted by a number of environmental factors (e.g., natural organic matter and metal oxides).

Chloropicrin Emission Reduction by Soil Amendment with Biochar

PubMed Central

Wang, Qiuxia; Yan, Dongdong; Liu, Pengfei; Mao, Liangang; Wang, Dong; Fang, Wensheng; Li, Yuan; Ouyang, Canbin; Guo, Meixia; Cao, Aocheng

2015-01-01

Biochar has sorption capacity, and can be used to enhance the sequestration of volatile organic contaminants such as pesticides in soil. Chloropicrin (CP) is an important soil fumigant for the production of many fruit and vegetable crops, but its emissions must be minimized to reduce exposure risks and air pollution. The objective of this study was to determine the capacity of biochar to adsorb CP and the effect of biochar amendments to soil on CP emission, concentration in the soil gas phase, degradation in soil and CP bioactivity for controlling soil borne pests. CP emission and concentration in the soil air phase were measured from packed soil columns after fumigant injection at 20-cm depth and application of selected doses of biocharto the surface 5 cm soil. Laboratory incubation and fumigation experiments were conducted to determine the capacity of biochar to adsorb CP, the effects on CP degradation and, separately, CP’s bioactivity on soil borne pests in soil amended with biochar. Biochar amendment at 2% to 5% (w/w) greatly reduced total CP emission losses by 85.7% - 97.7% compared to fumigation without biochar. CP concentrations in the soil gas-phase, especially in the top 5 cm of soil, were reduced within 48 h following application. The half-life of CP decreased from 13.6 h to 6.4 h as the biochar rate increased from 0% to 5%. CP and its metabolite (dichloronitromethane) both degraded more rapidly in pure biochar than in soil. The biochar used in the present study had a maximum adsorption capacity for CP of less than 5 mg g-1. There were no negative effects on pathogen and nematode control when the biochar used in this study was less than 1% (on a weight basis) in soil. Biochar amendment to soil reduced the emissions of CP. CP concentrations in the top 5 cm of soil gas-phase were reduced. CP degradation was accelerated with the addition of biochar. The biochar used in the present study had a low adsorption capacity for CP. There were no negative effects on pathogen and nematode control when the biochar amendment rate was less than 1% (by weight). The findings would be useful for establishing guidelines for biochar use in soil fumigation. PMID:26075904

Soil GHG emissions in a Miscanthus plantation as affected by increasing rates of biochar application.

NASA Astrophysics Data System (ADS)

Panzacchi, P.; Davies, C. A.; Ventura, M.; Michie, E. J.; Tonon, G.

2012-04-01

Biochar is defined as charcoal produced by pyrolysis with the aim to apply it to the soil in order to improve its fertility and carbon (C) storage capacity. Biochar physical and chemical properties can vary depending on the original biomass feedstock and pyrolysis conditions. The potential agricultural benefits and CO2 carbon sequestration from the application of biochar to soil, were assessed in field trials with well characterised biochar. In May 2010 we applied biochar from Miscanthus biomass produced at 450 °C at 3 different application rates: 10, 25 and 50 tons ha-1 to a 6 year old Miscanthus x giganteus plantation in Brattleby (Lincoln, UK) . Each treated 25 m2 plot had 4 replicates according to a randomised block experimental design. Biochar was incorporated to a depth of 10 cm in the soil between plant rhizomes after the harvest, through shallow tilling. CO2 emissions from biochar amended soil were monitored every two weeks by a portable infrared gas analyser (IRGA) with a closed dynamic chamber system, and continuously through 8 automated chambers (both systems from Li-COR, Lincoln, Nebraska). N2O fluxes were monitored using a closed static chamber technique with manual gas sampling and subsequent gas chromatography. Cation/anion exchange resin lysimeters were buried 20 cm deep in order to capture the leached nitrogen. Higher biochar applications led to a reduction of CO2 effluxes in the first 10 weeks of the experiment, after which no treatment effect was observed. The emission of N2O was significantly reduced in the 25 and 50 tons ha-1 application rates. Addition of biochar had no significant affect on the surface soil temperature, however the temperature sensitivity of soil respiration in the biochar treated plots decreased with increasing application rates

Biochar provides a safe and value-added solution for hyperaccumulating plant disposal: A case study of Phytolacca acinosa Roxb. (Phytolaccaceae).

PubMed

Wang, Shengsen; Gao, Bin; Li, Yuncong; Ok, Yong Sik; Shen, Chaofeng; Xue, Shengguo

2017-07-01

In this work, an innovative approach using biochar technology for hyperaccumulator disposal was developed and evaluated. The heavy metal enriched P. acinosa biomass (PBM) was pyrolyzed to produce biochar (PBC). Both PBM and PBC were characterized with X-ray diffraction (XRD) for crystal phases, scanning electron microscopy (SEM) for surface topography, and analyzed for elemental composition and mobility. The results revealed that whewellite, a dominant crystal form in biomass, was decomposed to calcite after pyrolysis. Elemental analysis indicated that 91-99% total non-volatile elements in the biomass were retained in the biochar. The toxicity characteristic leaching procedure (TCLP) results revealed that 94.6% and 0.15% of total Mn was extracted for biomass and biochar, respectively. This suggests that mobility and bioavailability of Mn in biochar was much lower relative to pristine biomass. Batch sorption experiment showed that excellent removal of aqueous silver, lead, cadmium, and copper ions can be achieved with PBC. Findings from this work indicated that biochar technology can provide a value-added solution for hyperaccumulator disposal. Copyright © 2017 Elsevier Ltd. All rights reserved.

Capacity of biochar application to maintain energy crop productivity: soil chemistry, sorghum growth, and runoff water quality effects.

PubMed

Schnell, Ronnie W; Vietor, Donald M; Provin, Tony L; Munster, Clyde L; Capareda, Sergio

2012-01-01

Pyrolysis of crop biomass generates a by-product, biochar, which can be recycled to sustain nutrient and organic C concentrations in biomass production fields. We evaluated effects of biochar rate and application method on soil properties, nutrient balance, biomass production, and water quality. Three replications of eight sorghum [ (L.) Moench] treatments were installed in box lysimeters under greenhouse conditions. Treatments comprised increasing rates (0, 1.5, and 3.0 Mg ha) of topdressed or incorporated biochar supplemented with N fertilizer or N, P, and K fertilizer. Simulated rain was applied at 21 and 34 d after planting, and mass runoff loss of N, P, and K was measured. A mass balance of total N, P, and K was performed after 45 d. Returning 3.0 Mg ha of biochar did not affect sorghum biomass, soil total, or Mehlich-3-extractable nutrients compared to control soil. Yet, biochar contributed to increased concentration of dissolved reactive phosphorus (DRP) and mass loss of total phosphorus (TP) in simulated runoff, especially if topdressed. It was estimated that up to 20% of TP in topdressed biochar was lost in surface runoff after two rain events. Poor recovery of nutrients during pyrolysis and excessive runoff loss of nutrients for topdressed biochar, especially K, resulted in negative nutrient balances. Efforts to conserve nutrients during pyrolysis and incorporation of biochar at rates derived from annual biomass yields will be necessary for biochar use in sustainable energy crop production. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Immobilization of Cu2+ and Cd2+ by earthworm manure derived biochar in acidic circumstance.

PubMed

Wang, Zhanghong; Shen, Fei; Shen, Dekui; Jiang, Yahui; Xiao, Rui

2017-03-01

Earthworm manure, the by-product obtained from the disposing of biowastes by earthworm breeding, is largely produced and employed as a feedstock for biochar preparation through pyrolysis. For repairing acidic soil or acidic electroplating effluent, biochar physicochemical properties would suffer from some changes like an acidic washing process, which hence affected its application functions. Pristine biochar (UBC) from pyrolysis of earthworm manure at 700°C and biochar treated by HCl (WBC) were comparatively investigated regarding their physicochemical properties, adsorption capability and adsorption mechanism of Cu 2+ and Cd 2+ from aqueous solution to explore the immobilization characteristics of biochar in acidic environment. After HCl treatment, the soluble ash content and phenolic-OH in the WBC sample was notably decreased against the increase of the carboxyl CO, aromatic CC and Si-O-Si, compared to that of UBC. All adsorption processes can be well described by Langmuir isotherm model. The calculated maximum adsorption capacity of Cu 2+ and Cd 2+ adsorption on UBC were 36.56 and 29.31mg/g, respectively, which were higher than that of WBC (8.64 and 12.81mg/g, respectively), indicating that HCl treatment significantly decreased biochar adsorption ability. Mechanism analysis revealed that alkali and alkaline earth metallic, salts (carbonates, phosphates and silicates), and surface functional groups were responsible for UBC adsorption, corresponding to ion exchange, precipitation and complexation, respectively. However, ion exchange made little contributions to WBC adsorption due to the great loss of soluble ash content. WBC adsorption was mainly attributed to the abundant exposure of silicates and surface functional groups (carboxyl CO and aromatic CC). Copyright © 2016. Published by Elsevier B.V.

Potential risk of biochar-amended soil to aquatic systems: an evaluation based on aquatic bioassays.

PubMed

Bastos, A C; Prodana, M; Abrantes, N; Keizer, J J; Soares, A M V M; Loureiro, S

2014-11-01

It is vital to address potential risks to aquatic ecosystems exposed to runoff and leachates from biochar-amended soils, before large scale applications can be considered. So far, there are no established approaches for such an assessment. This study used a battery of bioassays and representative aquatic organisms for assessing the acute toxicity of water-extractable fractions of biochar-amended soil, at reported application rates (80 t ha(-1)). Biochar-amended aqueous soil extracts contained cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), manganese (Mn), zinc (Zn), nickel (Ni), lead (Pb), arsenic (As) and mercury (Hg) (Σmetals 96.3 µg l(-1)) as well as the 16 priority PAHs defined by the U.S. Environmental Protection Agency (Σ16PAHs 106 ng l(-1)) at contents in the range of current EU regulations for surface waters. Nevertheless, acute exposure to soil-biochar (SB) extracts resulted in species-specific effects and dose-response patterns. While the bioluminescent marine bacterium Vibrio fischeri was the most sensitive organism to aqueous SB extracts, there were no effects on the growth of the microalgae Pseudokirchneriella subcapitata. In contrast, up to 20 and 25% mobility impairment was obtained for the invertebrate Daphnia magna upon exposure to 50 and 100% SB extract concentrations (respectively). Results suggest that a battery of rapid and cost-effective aquatic bioassays that account for ecological representation can complement analytical characterization of biochar-amended soils and risk assessment approaches for surface and groundwater protection.

Adsorption and desorption of ammonium by maple wood biochar as a function of oxidation and pH.

PubMed

Wang, Bing; Lehmann, Johannes; Hanley, Kelly; Hestrin, Rachel; Enders, Akio

2015-11-01

The objective of this work was to investigate the retention mechanisms of ammonium in aqueous solution by using progressively oxidized maple wood biochar at different pH values. Hydrogen peroxide was used to oxidize the biochar to pH values ranging from 8.1 to 3.7, with one set being adjusted to a pH of 7 afterwards. Oxidizing the biochars at their lowered pH did not increase their ability to adsorb ammonium. However, neutralizing the oxygen-containing surface functional groups on oxidized biochar to pH 7 increased ammonia adsorption two to three-fold for biochars originally at pH 3.7-6, but did not change adsorption of biochars oxidized to pH 7 and above. The adsorption characteristics of ammonium are well described by the Freundlich equation. Adsorption was not fully reversible in water, and less than 27% ammonium was desorbed in water in two consecutive steps than previously adsorbed, for biochars with a pH below 7, irrespective of oxidation. Recovery using an extraction with 2M KCl increased from 34% to 99% of ammonium undesorbed by both preceding water extractions with increasing oxidation, largely irrespective of pH adjustment. Unrecovered ammonium in all extractions and residual biochar was negligible at high oxidation, but increased to 39% of initially adsorbed amounts at high pH, likely due to low amounts adsorbed and possible ammonia volatilization losses. Copyright © 2015 Elsevier Ltd. All rights reserved.

Feasibility of biochar application on a landfill final cover-a review on balancing ecology and shallow slope stability.

PubMed

Chen, Xun-Wen; Wong, James Tsz-Fung; Ng, Charles Wang-Wai; Wong, Ming-Hung

2016-04-01

Due to the increasing concerns on global warming, scarce land for agriculture, and contamination impacts on human health, biochar application is being considered as one of the possible measures for carbon sequestration, promoting higher crop yield and contamination remediation. Significant amount of researches focusing on these three aspects have been conducted during recent years. Biochar as a soil amendment is effective in promoting plant performance and sustainability, by enhancing nutrient bioavailability, contaminants immobilization, and microbial activities. The features of biochar in changing soil physical and biochemical properties are essential in affecting the sustainability of an ecosystem. Most studies showed positive results and considered biochar application as an effective and promising measure for above-mentioned interests. Bio-engineered man-made filled slope and landfill slope increasingly draw the attention of geologists and geotechnical engineers. With increasing number of filled slopes, sustainability, low maintenance, and stability are the major concerns. Biochar as a soil amendment changes the key factors and parameters in ecology (plant development, soil microbial community, nutrient/contaminant cycling, etc.) and slope engineering (soil weight, internal friction angle and cohesion, etc.). This paper reviews the studies on the production, physical and biochemical properties of biochar and suggests the potential areas requiring study in balancing ecology and man-made filled slope and landfill cover engineering. Biochar-amended soil should be considered as a new type of soil in terms of soil mechanics. Biochar performance depends on soil and biochar type which imposes challenges to generalize the research outcomes. Aging process and ecotoxicity studies of biochar are strongly required.

Calibrating a method for simulated long-term ageing of biochar

NASA Astrophysics Data System (ADS)

Sohi, Saran; Cross, Andrew

2013-04-01

We recently established a procedure that imposes oxidatiave ageing to biochar and charcoal samples over a short time-frame, that provided carbon mass loss in the range projected for wild-fire charcoal in soil over a period of approximately 100 years. The stability of biochar samples in soil (relative to charcoal) range from 45-98% could be determined repeatably with high precision. Initial tests to understand the kinetics of the accelerated ageing method showed progressive increase in surface O concentration when examined by X-ray photoelectron spectroscopy (XPS) that slowly reached equilibrium. These trends resembled patterns observed in climate-for-time studies elsewhere, on centennial time-frame. We have extended this work to a preliminary direct calibration by matching progressive oxidation achieved in the laboratory to the surface composition of charcoal fragments recovered from the environment after periods of hundred to thousands of years. We have also applied artificial ageing to the same sets of naturally pre-aged charcoal fragments, and to recreated fresh charcoal. In this presentation of the first approach to quantifiably relate a laboratory test for biochar carbon stability to field data covering multiple time scales, we report on both the process and the implications for the stability of carbon stored in biochar under different climates and diverse agro-ecosystems.

Assessing the effect of biochar on erosion by using a high precision rainfall simulator

NASA Astrophysics Data System (ADS)

Goldman, Nina; Mayer, Marius; Fister, Wolfgang

2017-04-01

Numerus studies have explored the effect of biochar as a soil amendment and its beneficial effects on different soil properties. Adding biochar to soils might also act as a long-term carbon sink, which would mitigate the anthropogenic climate change. However, there are limitations regarding the current process knowledge on the effects of biochar on soil erosion and its erodibility. First test results point towards lower erosion rates of the substrates, which were enriched with biochar. In contrast, biochar concurrently shows relatively high erosion rates due to its lower bulk density, which makes it more susceptible to erosion. However, the number of conducted experiments does not yet allow quantitative statements. The overall objectives of this study are to gain insight into the process knowledge of erodibility of soils with incorporated biochar, and to develop new techniques for their observation. A drip type rainfall simulator is used on a microscale flume (0.2m2) to be able to control and monitor the thin surface flows and rainfall characteristics precisely. Two different types of biochars (high and low temperature pyrolysis) are used in combination with different substrates ranging from pure sand to naturally developed soils. Depending on the particle size and density of the biochar, different erosion rates can be observed. Particle analysis of the eroded material produces insights into which particle sizes and forms are preferably eroded. Since differentiation between eroded soil organic matter and biochar is very difficult without the use of heavy acids, two new methods are being developed and tested to monitor erosion rates of biochar. Comparing the original substrate with the eroded sediment by means of photogrammetry and isotope analysis, it should be possible to infer how much biochar was discharged and to assess the actual particle movement on the erosion flume. The results of this study could provide guidelines for the types of biochar that should be incorporated into fields as well as to calculate the potential monetary loss due to biochar discharge through rainfall events.

Escherichia coli Removal in Biochar-Modified Biofilters: Effects of Biofilm

PubMed Central

Afrooz, A. R. M. Nabiul; Boehm, Alexandria B.

2016-01-01

The presence of microbial contaminants in urban stormwater is a significant concern for public health; however, their removal by traditional stormwater biofilters has been reported as inconsistent and inadequate. Recent work has explored the use of biochar to improve performance of stormwater biofilters under simplified conditions that do not consider potential effects of biofilm development on filter media. The present study investigates the role of biofilm on microbial contaminant removal performance of stormwater biofilters. Pseudomonas aeruginosa biofilms were formed in laboratory-scale sand and biochar-modified sand packed columns, which were then challenged with Escherichia coli laden synthetic stormwater containing natural organic matter. Results suggests that the presence of biofilm influences the removal of E. coli. However, the nature of the influence depends on the specific surface area and the relative hydrophobicity of filter media. The distribution of attached bacteria within the columns indicates that removal by filter media varies along the length of the column: the inlet was the primary removal zone regardless of experimental conditions. Findings from this research inform the design of field-scale biofilters for better and consistent performance in removing microbial contaminants from urban stormwater. PMID:27907127

Arsenic removal in aqueous solution by a novel Fe-Mn modified biochar composite: Characterization and mechanism.

PubMed

Lin, Lina; Qiu, Weiwen; Wang, Di; Huang, Qing; Song, Zhengguo; Chau, Henry Wai

2017-10-01

The aim of this study was to develop a cost-effective method for As removal from aqueous systems. To this end, pristine biochar (BC) was impregnated with Fe-Mn oxides and a comparative analysis was conducted on the adsorption capacities of BC, Fe-Mn binary oxide (FMO), and Fe/Mn modified biochar (FMBC). The ferromanganese oxides increased the specific surface areas of BC. FMBC presented greater adsorption of As (Q max = 8.25mgg -1 ) than FMO and BC. Energy dispersive spectrometer analysis and electron microscope scanning revealed numerous pores of FMBC with the existence of Fe-Mn oxide using. Distinguished binding energy shifting of the As3d, Fe2p, O1s, and Mn2p3/2 regions after As sorption were found, indicating that Mn(III) oxidation and interaction of oxygen-containing function groups in the FMBC promoted the conversion of As(III) to As(V). Furthermore, chemisorption was found to be the main mechanism for As sorption on FMBC. Thus, the results suggest that FMBC could be used as an inexpensive and highly efficient adsorbent for As removal from water environment. Copyright © 2017 Elsevier Inc. All rights reserved.

Influence of NH3 concentration on biomass nitrogen-enriched pyrolysis.

PubMed

Chen, Wei; Li, Kaixu; Xia, Mingwei; Chen, Yingquan; Yang, Haiping; Chen, Zhiqun; Chen, Xu; Chen, Hanping

2018-05-08

In this study, nitrogen was used to replace oxygen through biomass N-enriched pyrolysis in a fixed-bed reactor to obtain N-containing chemicals and N-doped biochar. Influence of NH 3 concentration on the formation mechanism of N-species and electrochemical performance of N-doped biochar was investigated in depth. Results showed that increasing NH 3 concentration promoted bio-oil and gas generation, and increased H 2 , CH 4 and CO yield at the diminishing of CO 2 . Simultaneously, bio-oil showed lower oxygen content with non-methoxy phenols and N-heterocyclics as the main components, and the maximums were 57.73% and 16.21% at 80 vol% NH 3 concentration, respectively. With regard to solid N-doped biochar, nitrogen content (4.85 wt%), N-containing groups and specific surface area (369.59 m 2 /g) increased greatly, and excellent electrochemical property (120 F/g) was shown with NH 3 concentration increasing. However, NH 3 conversion efficiency decreased gradually with NH 3 increasing, and 40 vol% may be the optimum NH 3 concentration for biomass N-enriched pyrolysis. Copyright © 2018 Elsevier Ltd. All rights reserved.

Potential dual use of biochar for wastewater treatment and soil amelioration

NASA Astrophysics Data System (ADS)

Marschner, Bernd; Werner, Steffen; Alfes, Karsten; Lübken, Manfred

2013-04-01

Irrigating crops with wastewater from open drainage channels is a common practice in urban agricultural production in many dry regions of Africa, Asia and Latin America. While the wastewater-borne nutrients reduce the need for inputs of mineral fertilizers or manures and thus reduce production costs, wastewater-borne pathogens and contaminants pose a health risk for the producers and consumers of the crops. Furthermore, the input of nutrients with the irrigation water may greatly exceed crop requirements and thus lead to unproductive leaching losses of nutrients. It is generally acknowledged that biochar additions can increase the soil's sorption and retention capacity for nutrients and water. However, positive effects on crop production are generally only observed, if this is combined with mineral fertilizers or manures due to the low nutrient content of biochars. Biochar possibly also has a high potential for use in water purification, replacing the coal-based activated carbon as a sorbent for contaminants and pathogens. It was therefore hypothesized that biochar can be used for pathogen removal from wastewater while at the same time being loaded with nutrients and contaminants. If contaminants are of minor concern the "loaded" biochar can be used as a soil amendment, providing not only long-term sorption capacity but also nutrients. Experiments were conducted with pyrochar from Miscanthus, rice husks and wood chips, which strongly differed in elemental composition, MIR-DRIFT spectra, surface charge properties and sorption potential for DOC and phosphate. When used as top filter layer in a sand column system, the biochars effectively reduced E. coli concentrations from raw wastewater by up to 2 log units. While biochars from rice husks and Miscanthus accumulated N substantially, wood chip biochar showed no N retention. On the other hand, P accumulation was most pronounced for wood chip biochar. Ongoing incubation experiments with the "loaded" and fresh biochar in soils indicate that the pretreatment with wastewater alters biochar's stability and their effects on N-mineralization.

Methodological interference of biochar in the determination of extracellular enzyme activities in composting samples

NASA Astrophysics Data System (ADS)

Jindo, K.; Matsumoto, K.; García Izquierdo, C.; Sonoki, T.; Sanchez-Monedero, M. A.

2014-03-01

Biochar application has received increasing attention as a means to trap recalcitrant carbon and enhance soil fertility. Hydrolytic enzymatic assays, such as β-glucosidase and phosphatase activities, are used for the assessment of soil quality and composting process, which are based on use of p-nitrophenol (PNP) derivatives as substrate. However, sorption capacity of biochar can interfere colorimetric determination of the hydrolysed PNP, either by the sorption of the substrate or the reaction-product of hydrolysis into biochar surface. The aim of the present work is to study the biochar sorption capacity for PNP in biochar-blended composting mixtures in order to assess its impact on the estimation of the colorimetric-based enzymatic assays. A retention test was conducted by adding a solution of known amounts of PNP in universal buffer solution (pH = 5, 6.5 and 11, corresponding to the β-glucosidase, acid and alkaline phosphatase activity assays, respectively), in samples taken at the initial stage and after maturation stage from 4 different composting piles (two manure composting piles (PM: poultry manure, CM: cow manure) and two other similar piles containing 10% of additional biochar (PM + B, CM + B)). The results show that biochar blended composts (PM + B, CM + B) generally exhibited low enzymatic activities, compared to manure compost without biochar (PM, CM). In terms of the difference between the initial and maturation stage of composting process, the PNP retention in biochar was shown more clearly at maturation stage, caused by an enlarged proportion of biochar inside compost mixture after the selective degradation of easily decomposable organic matter. The retention of PNP was more pronounced at low pH (5 and 6.5) than at high pH (11), 3 reflecting on pH dependency of sorption 49 capacity of biochar and/or PNP 50 solubility.

Hydrogen production from biomass gasification using biochar as a catalyst/support.

PubMed

Yao, Dingding; Hu, Qiang; Wang, Daqian; Yang, Haiping; Wu, Chunfei; Wang, Xianhua; Chen, Hanping

2016-09-01

Biochar is a promising catalyst/support for biomass gasification. Hydrogen production from biomass steam gasification with biochar or Ni-based biochar has been investigated using a two stage fixed bed reactor. Commercial activated carbon was also studied as a comparison. Catalyst was prepared with an impregnation method and characterized by X-ray diffraction, specific surface and porosity analysis, X-ray fluorescence and scanning electron micrograph. The effects of gasification temperature, steam to biomass ratio, Ni loading and bio-char properties on catalyst activity in terms of hydrogen production were explored. The Ni/AC catalyst showed the best performance at gasification temperature of 800°C, S/B=4, Ni loading of 15wt.%. Texture and composition characterization of the catalysts suggested the interaction between volatiles and biochar promoted the reforming of pyrolysis volatiles. Cotton-char supported Ni exhibited the highest activity of H2 production (64.02vol.%, 92.08mgg(-1) biomass) from biomass gasification, while rice-char showed the lowest H2 production. Copyright © 2016 Elsevier Ltd. All rights reserved.

Biochar decreases dissolved organic carbon but not nitrate leaching in relation to vinasse application in a Brazilian sugarcane soil.

PubMed

Eykelbosh, Angela Joy; Johnson, Mark S; Couto, Eduardo Guimarães

2015-02-01

Sugarcane cultivation is associated with catchment-wide impacts related to application of vinasse, a nutrient-dense effluent with high eutrophication potential. We evaluated the potential for biochar (charcoal produced from pyrolyzed filtercake) to mitigate carbon and nutrient leaching in a cultivated Brazilian Ferralsol after vinasse application. Twelve soil columns (soil alone [S], soil with vinasse [SV], soil with vinasse and biochar [SVB], and soil with biochar [SB]) were flushed with water and then treated with water or vinasse. Samples collected via vacuum filtration were examined via UV-Vis and fluorescence spectroscopy. Biochar attenuated dissolved organic carbon (DOC) leaching in soil (S vs. SB) as well as in relation to vinasse application (SV vs. SVB). Biochar-amended soil preferentially retained high-molecular weight, humic-like DOC species, as revealed by fluorescence spectroscopy and optical indices, but did not retain low-weight amino acid-like species. Vinasse application also increased total NO3(-) flux, which may have been exacerbated by biochar co-application. Vinasse treatment strongly affects carbon and NO3(-) fluxes in this tropical soil. Biochar attenuated DOC leaching, likely through stabilization of complex compounds already present in soil, but did not lessen NO3(-) fluxes. Thus, biochar amendments in vinasse application areas may decrease carbon leaching. Copyright © 2014 Elsevier Ltd. All rights reserved.

Preparation of porous bio-char and activated carbon from rice husk by leaching ash and chemical activation.

PubMed

Ahiduzzaman, Md; Sadrul Islam, A K M

2016-01-01

Preparation porous bio-char and activated carbon from rice husk char study has been conducted in this study. Rice husk char contains high amount silica that retards the porousness of bio-char. Porousness of rice husk char could be enhanced by removing the silica from char and applying heat at high temperature. Furthermore, the char is activated by using chemical activation under high temperature. In this study no inert media is used. The study is conducted at low oxygen environment by applying biomass for consuming oxygen inside reactor and double crucible method (one crucible inside another) is applied to prevent intrusion of oxygen into the char. The study results shows that porous carbon is prepared successfully without using any inert media. The adsorption capacity of material increased due to removal of silica and due to the activation with zinc chloride compared to using raw rice husk char. The surface area of porous carbon and activated carbon are found to be 28, 331 and 645 m(2) g(-1) for raw rice husk char, silica removed rice husk char and zinc chloride activated rice husk char, respectively. It is concluded from this study that porous bio-char and activated carbon could be prepared in normal environmental conditions instead of inert media. This study shows a method and possibility of activated carbon from agro-waste, and it could be scaled up for commercial production.

Characterization of organic compounds in biochars derived from municipal solid waste.

PubMed

Taherymoosavi, Sarasadat; Verheyen, Vince; Munroe, Paul; Joseph, Stephen; Reynolds, Alicia

2017-09-01

Municipal solid waste (MSW) generation has been growing in many countries, which has led to numerous environmental problems. Converting MSW into a valuable biochar-based by-product can manage waste and, possibly, improve soil fertility, depending on the soil properties. In this study, MSW-based biochars, collected from domestic waste materials and kerbsides in two Sydney's regions, were composted and pyrolysed at 450°C, 550°C and 650°C. The characteristics of the organic components and their interactions with mineral phases were investigated using a range of analytical techniques, with special attention given to polycyclic aromatic hydrocarbons and heavy metal concentrations. The MSW biochar prepared at 450°C contained the most complex organic compounds. The highest concentration of fixed C, indicating the stability of biochar, was detected in the high-temperature-biochar. Microscopic analysis showed development of pores and migration of mineral phases, mainly Ca/P/O-rich phases, into the micro-pores and Si/Al/O-rich phases on the surface of the biochar in the MSW biochar produced at 550°C. Amalgamation of organic phases with mineral compounds was observed, at higher pyrolysis temperatures, indicating chemical reactions between these two phases at 650°C. XPS analysis showed the main changes occurred in C and N bonds. During heat treatment, N-C/C=N functionalities decomposed and oxidized N configurations, mainly pyridine-N-oxide groups, were formed. The majority of the dissolved organic carbon fraction in both MSW biochar produced at 450°C and 550°C was in the form of building blocks, whereas LMW acids was the main fraction in high-temperature-biochar (59.9%). Copyright © 2017 Elsevier Ltd. All rights reserved.

Recovery of phosphate from aqueous solution by magnesium oxide decorated magnetic biochar and its potential as phosphate-based fertilizer substitute.

PubMed

Li, Ronghua; Wang, Jim J; Zhou, Baoyue; Awasthi, Mukesh Kumar; Ali, Amjad; Zhang, Zengqiang; Lahori, Altaf Hussain; Mahar, Amanullah

2016-09-01

The present study deals with the preparation of a novel MgO-impregnated magnetic biochar (MMSB) for phosphate recovery from aqueous solution. The MMSB was evaluated against sugarcane harvest residue biochar (SB) and magnetic biochar without Mg (MSB). The results showed that increasing Mg content in MMSB greatly improved the phosphate adsorption compared to SB and MSB, with 20% Mg-impregnated MMSB (20MMSB) recovering more than 99.5% phosphate from aqueous solution. Phosphate adsorption capacity of 20MMSB was 121.25mgP/g at pH 4 and only 37.53% of recovered phosphate was desorbed by 0.01mol/L HCl solutions. XRD and FTIR analysis showed that phosphate sorption mechanisms involved predominately with surface electrostatic attraction and precipitation with impregnated MgO and surface inner-sphere complexation with Fe oxide. The 20MMSB exhibited both maximum phosphate sorption and strong magnetic separation ability. Overall, phosphate-loaded 20MMSB significantly enhanced plant growth and could be used as a potential substitute for phosphate-based fertilizer. Copyright © 2016 Elsevier Ltd. All rights reserved.

Characterization and Phenanthrene Sorption of Natural and Pyrogenic Organic Matter Fractions.

PubMed

Jin, Jie; Sun, Ke; Wang, Ziying; Yang, Yan; Han, Lanfang; Xing, Baoshan

2017-03-07

Pyrogenic humic acid (HA) is released into the environment during the large-scale application of biochar. However, the biogeochemistry of pyrogenic organic matter (PyOM) fractions and their sorption of hydrophobic organic compounds (HOCs) are poorly understood in comparison with natural organic matter (NOM) fractions. HA and humin (HM) fractions isolated from soils and the oxidized biochars were characterized. Sorption of phenanthrene (PHE) by these fractions was also examined. The characterization results demonstrate that pyrogenic HAs are different from natural HAs, with the former having lower atomic H/C ratios, more abundant aromatic C, and higher concentrations of surface carboxylic groups. Compared with the fresh biochars, the K oc of PHE on their oxidized biochars, pyrogenic HA, and HM fractions were undiminished, which is encouraging for the use of biochar in soil remediation. The PyOM fractions exhibited stronger nonlinear sorption than the NOM fractions. In addition, the PyOM fractions had higher sorption capacity than the NOM fractions due to their low polar C content and high aryl C content. The results obtained from this work will shed new light on the impact of the addition of biochar on the biogeochemistry of soil organic matter and on the fate of HOCs in biochar-amended soil.

Characterization of metal binding sites onto biochar using rare earth elements as a fingerprint.

PubMed

Pourret, Olivier; Houben, David

2018-02-01

The ability of biochar to immobilize metals relies on the amount of functional groups at its surface but the contribution of each functional groups (e.g. carboxylic, phenolic) to metal bonding is poorly known. Using a new approach based on previous works on rare earth element (REE) interactions with humic substances, we aim at elucidating the relative contribution of these binding sites to metal sorption under various conditions (i.e. pH and ionic strengths, IS). Using batch experiments, REE sorption onto biochar was analyzed from pH 3 to 9 and IS 10 -1 mol/L to 10 -3 mol/L. Rare earth element patterns show a Middle REE (MREE) downward concavity at acidic pH and low ionic strength. These patterns are in good agreement with existing datasets quantifying REE binding with humic substances. Indeed, the MREE downward concavity displayed by REE-biochar complexation pattern compares well with REE patterns with various organic compounds. This similarity in the REE complexation pattern shapes suggests that carboxylic groups are the main binding sites of REE in biochar. Overall, our results indicate that the strength of the metal bonding with biochar increases when pH and IS increase, suggesting that biochar is more efficient for long-term metal immobilization at near neutral pH and high ionic strength.

Enhancing phosphate adsorption by Mg/Al layered double hydroxide functionalized biochar with different Mg/Al ratios.

PubMed

Li, Ronghua; Wang, Jim J; Zhou, Baoyue; Awasthi, Mukesh Kumar; Ali, Amjad; Zhang, Zengqiang; Gaston, Lewis A; Lahori, Altaf Hussain; Mahar, Amanullah

2016-07-15

Mg/Al ratio plays a significant role for anion adsorption by Mg/Al-layered double hydroxides (Mg/Al-LDHs) modified biochar. In this study, Mg/Al-LDHs biochar with different Mg/Al ratios (2, 3, 4) were prepared by co-precipitation for phosphate removal from aqueous solution. Factors on phosphate adsorption including Mg/Al ratio, pH, and the presence of other inorganic anions were investigated through batch experiments. Increasing Mg/Al ratio in the Mg/Al-LDHs biochar composites generally enhanced phosphate adsorption with Langmuir adsorption maximum calculated at 81.83mg phosphorous (P) per gram of 4:1Mg/Al-LDHs biochar at pH3.0. The adsorption process was best described by the pseudo-second-order kinetic model. Solution pH had greater effects on the phosphate adsorption by Mg/Al LDHs biochar composites with lower Mg/Al ratios. The presence of other inorganic anions decreased the phosphate adsorption efficiency in the order of F(-) > SO4(2-) > NO2(-) >Cl(-). Phosphate adsorption mechanism involves ion exchange, electrostatic attraction and surface inner-sphere complex formation. Overall, Mg/Al-LDHs biochar composites offer a potential alternative of carbon-based adsorbent for phosphate removal from aqueous solution. Copyright © 2016 Elsevier B.V. All rights reserved.

Immobilization of hexavalent chromium in contaminated soils using biochar supported nanoscale iron sulfide composite.

PubMed

Lyu, Honghong; Zhao, Hang; Tang, Jingchun; Gong, Yanyan; Huang, Yao; Wu, Qihang; Gao, Bin

2018-03-01

Biochar supported carboxymethyl cellulose (CMC)-stabilized nanoscale iron sulfide (FeS) composite (CMC-FeS@biochar) was prepared and tested for immobilization of hexavalent chromium Cr(VI) in soil. Results of UV-vis and transmission electron microscopy (TEM) showed that the backbone of biochar suppressed the aggregation of FeS, resulting in smaller particle size and more sorption sites than bare FeS. The composite at a dosage of 2.5 mg per gram soil displayed an enhanced Cr(VI) immobilization efficiency (a 94.7% reduction in the toxicity characteristic leaching procedure (TCLP) based leachability and a 95.6% reduction in the CaCl 2 extraction) compared to plain biochar and bare FeS. Sequential extraction procedure (SEP) and X-ray photoelectron spectroscopy (XPS) analysis suggested that CMC-FeS@biochar promoted the conversion of more accessible Cr (exchangeable and carbonate-bound fractions) into the less accessible forms (iron-manganese oxides-bound, organic material-bound, and residual fractions) to reduce the toxicity of Cr(VI) and that surface sorption and reduction were dominant mechanisms for Cr(VI) immobilization. CMC-FeS@biochar greatly reduced the bioavailability of Cr(VI) to wheat and earthworms (Eisenia fetida). Moreover, the application of CMC-FeS@biochar enhanced soil organic matter content and microbial activity. This work highlighted the potential of CMC-FeS@biochar composite as a low-cost, "green", and effective amendment for immobilizing Cr(VI) in contaminated soils and improving soil properties. Copyright © 2017 Elsevier Ltd. All rights reserved.

Biochar-macrofauna interplay: Searching for new bioindicators.

PubMed

Castracani, C; Maienza, A; Grasso, D A; Genesio, L; Malcevschi, A; Miglietta, F; Vaccari, F P; Mori, A

2015-12-01

Biochar incorporation in agricultural soils has been proposed as a climate change mitigation strategy and has proved to substantially increase crop productivity via physical, chemical and biological mechanisms. The changes induced in soil properties are known to have a direct impact on soil ecosystem with consequences for soil biota community that, in turn, can influence biochar aging in soil. Despite several studies investigated in the interplay between biochar and soil microbiology, there is a clear lack of information on groups that live in the most superficial ground layers: soil meso and macro fauna. These groups are of great importance if we consider that biochar application should ideally be located in the soil's surface layer (0-30 cm). Our study is the first attempt to investigate the interactions between biochar soil amendments and aboveground soil macro-meso fauna in a field crop. This was made setting-up a randomized-block experiment on a processing tomato crop in northern Italy, using three different biochar types and periodically monitoring soil parameters and fauna abundances along the crop growing cycle in summer 2013. Results show that the impact of biochar application on soil fauna as a whole is small when compared to that of agricultural management, suggesting that this amendment does not have short-term ecological interferences. Nevertheless, ants exhibited variations in abundances and distribution connected to properties of amended soils such as temperature, pH and humidity, proving that they can be effectively used as a target group in the study of interactions between biochar and soil biota. Copyright © 2015 Elsevier B.V. All rights reserved.

Water dynamics in different biochar fractions.

PubMed

Conte, Pellegrino; Nestle, Nikolaus

2015-09-01

Biochar is a carbonaceous porous material deliberately applied to soil to improve its fertility. The mechanisms through which biochar acts on fertility are still poorly understood. The effect of biochar texture size on water dynamics was investigated here in order to provide information to address future research on nutrient mobility towards plant roots as biochar is applied as soil amendment. A poplar biochar has been stainless steel fractionated in three different textured fractions (1.0-2.0 mm, 0.3-1.0 mm and <0.3 mm, respectively). Water-saturated fractions were analyzed by fast field cycling (FFC) NMR relaxometry. Results proved that 3D exchange between bound and bulk water predominantly occurred in the coarsest fraction. However, as porosity decreased, water motion was mainly associated to a restricted 2D diffusion among the surface-site pores and the bulk-site ones. The X-ray μ-CT imaging analyses on the dry fractions revealed the lowest surface/volume ratio for the coarsest fraction, thereby corroborating the 3D water exchange mechanism hypothesized by FFC NMR relaxometry. However, multi-micrometer porosity was evidenced in all the samples. The latter finding suggested that the 3D exchange mechanism cannot even be neglected in the finest fraction as previously excluded only on the basis of NMR relaxometry results. X-ray μ-CT imaging showed heterogeneous distribution of inorganic materials inside all the fractions. The mineral components may contribute to the water relaxation mechanisms by FFC NMR relaxometry. Further studies are needed to understand the role of the inorganic particles on water dynamics. Copyright © 2015 John Wiley & Sons, Ltd.

Effect of almond shell biochar addition on the hydro-physical properties of an arable Central Valley soil

NASA Astrophysics Data System (ADS)

Lopez, V.; Ghezzehei, T. A.

2014-12-01

Biochar is composed of any carbonaceous matter pyrolyzed under low oxygen exposure. Its use as a soil amendment to address soil infertility has been accelerated by studies reporting positive effects of enhanced nutrient retention, cation exchange capacity, microbial activity, and vegetative growth over time. Biochar has also been considered as a carbon sequestration method because of its reported environmental persistence. While the aforementioned effects are positive benefits of biochar's use, its impact on soil physical properties and water flow are equally important in maintaining soil fertility. This study aims to show how soil physical and hydraulic properties change over time with biochar addition. To address these aims, we conducted a 9 week microcosm incubation experiment with local arable loamy sand soils amended with biochar. Biochar was created from locally collected almond shells and differs by pyrolysis temperatures (350°C, 700°C) and size (<250 μm, 1-2mm). Additionally, biochar was applied to soil at a low (10 t/ha) or high (60 t/ha) rates. Changes in soil water flow properties were analyzed by infiltration or pressure cell experiments immediately after creating our soil-biochar mixtures. These experiments were repeated during and after the incubation period to observe if and how flow is altered over time. Following incubation and hydraulic experiments, a water drop penetration time (WDPT) test was conducted to observe any alterations in surface hydrophobicity. Changes in soil physical properties were analyzed by determining content of water stable aggregates remaining after wet sieving. This series of experiments is expected to provide a greater understanding on the impact biochar addition on soil physical and hydraulic properties. Furthermore, it provides insight into whether or not converting local agricultural waste into biochar for soil use will be beneficial, especially in agricultural systems undergoing climate stress.

Biochar produced from oak sawdust by Lanthanum (La)-involved pyrolysis for adsorption of ammonium (NH4(+)), nitrate (NO3(-)), and phosphate (PO4(3-)).

PubMed

Wang, Zhanghong; Guo, Haiyan; Shen, Fei; Yang, Gang; Zhang, Yanzong; Zeng, Yongmei; Wang, Lilin; Xiao, Hong; Deng, Shihuai

2015-01-01

A series of biochars were prepared by pyrolyzing oak sawdust with/without LaCl3 involvement at temperature of 300-600 °C, and approximate and ultimate analyses were carried out to check their basic characteristics. Meanwhile, the releases of readily soluble NH4(+), NO3(-) and PO4(3-) from biochars and the adsorption of NH4(+), NO3(-) and PO4(3-) by biochars were investigated. Results indicated that the involvement of LaCl3 in pyrolysis could advance the temperature of maximum mass loss by 10 °C compared with oak sawdust (CK), and potentially promoted biochar yield. Overall, the releases of readily soluble NH4(+), NO3(-) and PO4(3-) from biochars were negatively related to pyrolysis temperature, and the releases were greatly weakened by La-biochars. Additionally, the adsorption to NH4(+) can be promoted by the biochars produced at low temperature. On the contrary, the NO3(-) adsorption can be improved by increasing pyrolysis temperature. The highest PO4(3-) adsorption was achieved by the biochars produced at 500 °C. According to the results of adsorption isotherms, the maximum adsorption capacity of NH4(+), NO3(-) and PO4(3-) can be significantly promoted by 1.9, 11.2, and 4.5 folds using La-biochars. Based on the observations of FT-IR, SEM-EDS, and surface functional groups, the improvement of NH4(+) adsorption was potentially associated with the existing acidic function groups (phenolic-OH and carboxyl C=O). The increased basic functional groups on La-biochars were beneficial to improve NO3(-) and PO4(3-) adsorption. Besides, PO4(3-) adsorption was also potentially related to the formed La2O3. Copyright © 2014 Elsevier Ltd. All rights reserved.

Biochar carbon sequestration and downward translocation in contrasting soils under field conditions in Australia

NASA Astrophysics Data System (ADS)

Pal Singh, Bhupinder; Fang, Yunying; Boersma, Mark; Matta, Pushpinder; Van Zwieten, Lukas; Macdonald, Lynne

2014-05-01

Carbon (C) sequestration potential of biochar depends on its stability and stabilisation of native or added organic C in soil. However, the processes of biochar degradation, fate in soil organic matter pools, and downward translocation in the soil profile, and the influence of biochar on emissions or stabilisation of native organic C sources are poorly understood under field conditions. An Eucalyptus saligna green-waste biochar (δ13C -36.6o; total C 66.8%) produced by slow pyrolysis at 450° C was applied at 29.2 t ha-1 to 10-cm depth in circular (0.66-m diameter) micro-plots, encompassing three soils [Tenosol, Dermosol and Ferrosol (Australian Soil Classification); Arenosol, Planosol, Ferralsol (approximate WRB Classification] under contrasting pasture systems across New South Wales and Tasmania (Australia). The aims of this study were to (i) monitor the fate of biochar C in respired CO2 and quantify biochar stability and stabilisation under field conditions, (ii) determine the influence of biochar on native soil C emissions, and (iii) track downward migration of the surface (0-10 cm) applied biochar over a 1-year period. We also periodically monitored the impact of biochar on microbial biomass carbon (MBC) and aboveground biomass production. The soils were separated into light and heavy C fractions and the C recovery of applied biochar C was calculated at 0-8, 8-12, 12-20 and 20-30 cm depths. Biochar C mineralisation rates were generally higher, albeit fluctuated widely, in the first 3 to 4 months. Over the first 7 months, the proportion of added biochar C mineralised in soils ranged between 1.4 and 5.5% and followed the sequence: Tenosol < Dermosol < Ferrosol. The mean residence time (MRT) of biochar ranged from 29 and 70 years. These values of MRT should be treated as highly conservative values, as they mainly reflect the MRT of relatively labile C components in biochar. The cumulative CO2-C emission over the 7-month period from native soil and plant sources was larger in the biochar-amended Tenosol, whereas lower in the biochar-amended Dermosol and Ferrosol, relative to the corresponding controls. As the aboveground biomass production was similar between the biochar-amended and control micro-plots during the first 7 months, the higher cumulative CO2-C emission in the biochar versus control Tenosol may be related to positive priming of native SOC mineralisation by biochar, and/or greater belowground allocation of plant-assimilated C, or possibly alternative effects (i.e. negative priming or lower belowground plant C allocation) in the Dermosol and Ferrosol. At 4 months, most of the applied biochar was recovered in the top 12 cm depth, with the total recovery of 72.1% in the Tenosol, 103.7% in the Dermosol and 79.2% in the Ferrosol. Biochar C was clearly migrated downward from the application depth (0-10 cm) within 4 months, particularly in Tenosol and Ferrosol, with the recovery of 4.8%, 2.7% and 12.7% in the 12-20 cm profile, and 6.0%, 1.1% and 9.1% at the 20-30 cm profile, across the Tenosol, Dermosol and Ferrosol, respectively. At 4 months, MBC was higher in the biochar-amended Tenosol and Dermosol than the corresponding controls, whereas, biochar had no effect on MBC in the Ferrosol, possibly due to its higher native organic C content cf. the other soil types. The updated results will be presented at the conference.

Preparation and Characterization of Biochars from Eichornia crassipes for Cadmium Removal in Aqueous Solutions.

PubMed

Li, Feng; Shen, Kaixuan; Long, Xiaolin; Wen, Jiasheng; Xie, Xiaojie; Zeng, Xiangyun; Liang, Yanyan; Wei, Yansha; Lin, Zefeng; Huang, Wenrou; Zhong, Ruida

2016-01-01

The study investigated the preparation and characterization of biochars from water hyacinth at 300°C to 700°C for cadmium (Cd) removal from aqueous solutions. The adsorption process was dominated by oxygen-containing functional groups with irregular surfaces via esterification reactions. Furthermore, the mineral components in the biochars also contributed to Cd absorption through precipitation. Parameters such as the effects of solution pH, contact time, and initial concentration were studied. The optimum pH value was observed at 5.0, in which nearly 90% of Cd was removed. The maximum Cd adsorption capacities based on the Langmuir isotherm were calculated at 49.837, 36.899, and 25.826 mg g(-1). The adsorption processes of the biochars followed the pseudo-second-order kinetics, with the equilibrium achieved around 5 h. The biochar from E. crassipes is a promising adsorbent for the treatment of wastewater, which can in turn convert one environmental problem to a new cleaning Technology.

Preparation and Characterization of Biochars from Eichornia crassipes for Cadmium Removal in Aqueous Solutions

PubMed Central

Li, Feng; Shen, Kaixuan; Long, Xiaolin; Wen, Jiasheng; Xie, Xiaojie; Zeng, Xiangyun; Liang, Yanyan; Wei, Yansha; Lin, Zefeng; Huang, Wenrou; Zhong, Ruida

2016-01-01

The study investigated the preparation and characterization of biochars from water hyacinth at 300°C to 700°C for cadmium (Cd) removal from aqueous solutions. The adsorption process was dominated by oxygen-containing functional groups with irregular surfaces via esterification reactions. Furthermore, the mineral components in the biochars also contributed to Cd absorption through precipitation. Parameters such as the effects of solution pH, contact time, and initial concentration were studied. The optimum pH value was observed at 5.0, in which nearly 90% of Cd was removed. The maximum Cd adsorption capacities based on the Langmuir isotherm were calculated at 49.837, 36.899, and 25.826 mg g−1. The adsorption processes of the biochars followed the pseudo-second-order kinetics, with the equilibrium achieved around 5 h. The biochar from E. crassipes is a promising adsorbent for the treatment of wastewater, which can in turn convert one environmental problem to a new cleaning Technology. PMID:26882239

Amending greenroof soil with biochar to affect runoff water quantity and quality.

PubMed

Beck, Deborah A; Johnson, Gwynn R; Spolek, Graig A

2011-01-01

Numbers of greenroofs in urban areas continue to grow internationally; so designing greenroof soil to reduce the amount of nutrients in the stormwater runoff from these roofs is becoming essential. This study evaluated changes in extensive greenroof water discharge quality and quantity after adding biochar, a soil amendment promoted for its ability to retain nutrients in soils and increase soil fertility. Prototype greenroof trays with and without biochar were planted with sedum or ryegrass, with barren soil trays used as controls. The greenroof trays were subjected to two sequential 7.4cm/h rainfall events using a rain simulator. Runoff from the rain events was collected and evaluated. Trays containing 7% biochar showed increased water retention and significant decreases in discharge of total nitrogen, total phosphorus, nitrate, phosphate, and organic carbon. The addition of biochar to greenroof soil improves both runoff water quality and retention. Copyright © 2011 Elsevier Ltd. All rights reserved.

Emissions and Char Quality of Flame-Curtain "Kon Tiki" Kilns for Farmer-Scale Charcoal/Biochar Production.

PubMed

Cornelissen, Gerard; Pandit, Naba Raj; Taylor, Paul; Pandit, Bishnu Hari; Sparrevik, Magnus; Schmidt, Hans Peter

2016-01-01

Pyrolysis of organic waste or woody materials yields charcoal, a stable carbonaceous product that can be used for cooking or mixed into soil, in the latter case often termed "biochar". Traditional kiln technologies for charcoal production are slow and without treatment of the pyrolysis gases, resulting in emissions of gases (mainly methane and carbon monoxide) and aerosols that are both toxic and contribute to greenhouse gas emissions. In retort kilns pyrolysis gases are led back to a combustion chamber. This can reduce emissions substantially, but is costly and consumes a considerable amount of valuable ignition material such as wood during start-up. To overcome these problems, a novel type of technology, the Kon-Tiki flame curtain pyrolysis, is proposed. This technology combines the simplicity of the traditional kiln with the combustion of pyrolysis gases in the flame curtain (similar to retort kilns), also avoiding use of external fuel for start-up. A field study in Nepal using various feedstocks showed char yields of 22 ± 5% on a dry weight basis and 40 ± 11% on a C basis. Biochars with high C contents (76 ± 9%; n = 57), average surface areas (11 to 215 m2 g-1), low EPA16-PAHs (2.3 to 6.6 mg kg-1) and high CECs (43 to 217 cmolc/kg)(average for all feedstocks, mainly woody shrubs) were obtained, in compliance with the European Biochar Certificate (EBC). Mean emission factors for the flame curtain kilns were (g kg-1 biochar for all feedstocks); CO2 = 4300 ± 1700, CO = 54 ± 35, non-methane volatile organic compounds (NMVOC) = 6 ± 3, CH4 = 30 ± 60, aerosols (PM10) = 11 ± 15, total products of incomplete combustion (PIC) = 100 ± 83 and NOx = 0.4 ± 0.3. The flame curtain kilns emitted statistically significantly (p<0.05) lower amounts of CO, PIC and NOx than retort and traditional kilns, and higher amounts of CO2. With benefits such as high quality biochar, low emission, no need for start-up fuel, fast pyrolysis time and, importantly, easy and cheap construction and operation the flame curtain technology represent a promising possibility for sustainable rural biochar production.

In Situ Persistence and Migration of Biochar Carbon and Its Impact on Native Carbon Emission in Contrasting Soils under Managed Temperate Pastures.

PubMed

Singh, Bhupinder Pal; Fang, Yunying; Boersma, Mark; Collins, Damian; Van Zwieten, Lukas; Macdonald, Lynne M

2015-01-01

Pyrogenic carbon (PyC) is an important component of the global soil carbon (C) pool, but its fate, persistence, and loss dynamics in contrasting soils and environments under planted field conditions are poorly understood. To fill this knowledge gap, a 13C-labelled biochar, as a surrogate material for PyC, produced from Eucalyptus saligna by slow pyrolysis (450°C; δ13C -36.7‰) was surface (0-10 cm) applied in C3 dominated temperate pasture systems across Arenosol, Cambisol and Ferralsol. The results show a low proportion of the applied biochar-C mineralised over 12 months in a relatively clay- and C-poor Arenosol (i.e., 2.0% loss via mineralisation), followed by a clay- and C-rich Cambisol (4.6%), and clay-, C- and earthworm-rich Ferralsol (7.0%). The biochar-C mean residence time (MRT), estimated by different models, varied between 44-1079 (Arenosol), 18-172 (Cambisol), and 11-29 (Ferralsol) years, with the shorter MRT estimated by a one-pool exponential and the longer MRT by an infinite-pool power or a two-pool exponential model. The two-pool model was best fitted to biochar-C mineralisation. The biochar-C recovery in the 12-30 cm soil layer varied from between 1.2% (Arenosol), 2.5-2.7% (Cambisol) and 13.8-15.7% (Ferralsol) of the applied biochar-C after 8-12 months. There was a further migration of biochar-C below the 50-cm depth in the Arenosol, as the combined biochar-C recovery in the mineralised pool and soil profile (up to 30 or 50 cm) was 82%, in contrast to 101% in the Cambisol and 104% in the Ferralsol after 12 months. These results indicate that the downward migration of biochar-C was greatest in the Arenosol (cf. Cambisol and Ferralsol). Cumulative CO2-C emission from native soil-plant sources was lower (p <0.10) in the biochar-amended vs. non-amended Ferralsol. This field-based study shows that the downward migration of biochar-C exceeded its loss via mineralisation in the Arenosol and Ferralsol, but not in the Cambisol. It is thus important to understand biochar-soil interactions to maximise long-term biochar C sequestration potential in planted soil systems.

In Situ Persistence and Migration of Biochar Carbon and Its Impact on Native Carbon Emission in Contrasting Soils under Managed Temperate Pastures

PubMed Central

Singh, Bhupinder Pal; Fang, Yunying; Boersma, Mark; Collins, Damian; Van Zwieten, Lukas; Macdonald, Lynne M

2015-01-01

Pyrogenic carbon (PyC) is an important component of the global soil carbon (C) pool, but its fate, persistence, and loss dynamics in contrasting soils and environments under planted field conditions are poorly understood. To fill this knowledge gap, a 13C-labelled biochar, as a surrogate material for PyC, produced from Eucalyptus saligna by slow pyrolysis (450°C; δ13C -36.7‰) was surface (0−10 cm) applied in C3 dominated temperate pasture systems across Arenosol, Cambisol and Ferralsol. The results show a low proportion of the applied biochar-C mineralised over 12 months in a relatively clay- and C-poor Arenosol (i.e., 2.0% loss via mineralisation), followed by a clay- and C-rich Cambisol (4.6%), and clay-, C- and earthworm-rich Ferralsol (7.0%). The biochar-C mean residence time (MRT), estimated by different models, varied between 44−1079 (Arenosol), 18−172 (Cambisol), and 11−29 (Ferralsol) years, with the shorter MRT estimated by a one-pool exponential and the longer MRT by an infinite-pool power or a two-pool exponential model. The two-pool model was best fitted to biochar-C mineralisation. The biochar-C recovery in the 12−30 cm soil layer varied from between 1.2% (Arenosol), 2.5−2.7% (Cambisol) and 13.8−15.7% (Ferralsol) of the applied biochar-C after 8−12 months. There was a further migration of biochar-C below the 50-cm depth in the Arenosol, as the combined biochar-C recovery in the mineralised pool and soil profile (up to 30 or 50 cm) was 82%, in contrast to 101% in the Cambisol and 104% in the Ferralsol after 12 months. These results indicate that the downward migration of biochar-C was greatest in the Arenosol (cf. Cambisol and Ferralsol). Cumulative CO2-C emission from native soil-plant sources was lower (p <0.10) in the biochar-amended vs. non-amended Ferralsol. This field-based study shows that the downward migration of biochar-C exceeded its loss via mineralisation in the Arenosol and Ferralsol, but not in the Cambisol. It is thus important to understand biochar-soil interactions to maximise long-term biochar C sequestration potential in planted soil systems. PMID:26509506

Formation of nanocarbon spheres by thermal treatment of woody char from fast pyrolysis process

Treesearch

Qiangu Yan; Hossein Toghiani; Zhiyong Cai; Jilei Zhang

2014-01-01

Influences of thermal treatment conditions of temperature, reaction cycle and time, and purge gas type on nanocarbon formation over bio-chars from fast pyrolysis and effects of thermal reaction cycle and purge gas type on bio-char surface functional groups were investigated by temperature-programmed desorption (TPD) and temperature programmed reduction methods....

Effect of biochar on the presence of nutrients and ryegrass growth in the soil from an abandoned indigenous coking site: The potential role of biochar in the revegetation of contaminated site.

PubMed

Zhang, Guixiang; Guo, Xiaofang; Zhu, Yuen; Han, Zhiwang; He, Qiusheng; Zhang, Fengsong

2017-12-01

Little is known regarding how biochars' feedstock and pyrolysis temperature affect soil function and plant growth. To address this gap in knowledge, 12 biochars (walnut shells, corn cobs, corn straws, and rice straws were separately pyrolyzed at 250, 400, and 600°C for 4h) were applied to soil from an indigenous coking site with application rate of 2.5% (w/w) in a pot experiment to determine the impact of biochar types on macro-nutrients (total and available N, P, and K) and ryegrass growth in the soil from an indigenous coking site. Generally, the total N, P, and K in the soil was not significantly different from that of the control group. However, biochars decreased the available N from 21.76mg·kg -1 for the control to 14.96mg·kg -1 . Corn straw and rice straw biochars increased the available P from 2.14mg·kg -1 for the control to 28.35mg·kg -1 , specifically at higher pyrolysis temperature, while walnut shell and corn cob biochars had little influence on it regardless of pyrolysis temperature. Biochars increased the available K from 173.58mg·kg -1 for the control to 355.64mg·kg -1 , varying as their feedstocks of corn cob>rice straw>corn straw>walnut shell and increasing with the increase of pyrolysis temperature. Correlation analysis suggests that it is responsible for the competition of soluble cations from biochars with K for adsorption sites on the soil surface. Biochars increased the ryegrass biomass from 0.07g·pot -1 for the control to 0.16g·pot -1 , with the generally most effective stimulation by biochars produced at 400°C. Ryegrass biomass had obviously positive correlation with available K, indicating its essential role in the growth of ryegrass in the studied soil. Copyright © 2017. Published by Elsevier B.V.

Significant plant growth stimulation by composted as opposed to untreated Biochar

NASA Astrophysics Data System (ADS)

Kammann, Claudia; Messerschmidt, Nicole; Müller, Christoph; Steffens, Diedrich; Schmidt, Hans-Peter; Koyro, Hans-Werner

2013-04-01

The application of production-fresh, untreated biochar does not always result in yield improvements, in particular in temperate or boreal soils. Therefore the use of biochar for soil C sequestration, although desirable from a global change mitigation point of view, may never be implemented without proven and economically feasible pathways for biochar effects in agriculture. To investigate earlier reports of the beneficial effects of composting biochar (e.g. Fischer & Glaser, 2012) we conducted a fully replicated (n=3, +/- biochar) large-scale composting study at the Delinat Institute in Arbaz, Switzerland. The materials were manures (bovine, horse and chicken), straw, stone meal and composting was performed with our without +20 vol.% of a woody biochar (German Charcoal GmbH). Interestingly, the rotting temperature was significantly higher in the biochar-compost while C and N were retained to a certain extent. To investigate the effect of composting ("ageing") on biochar effects, a completely randomized full-factorial pot study was carried out in the greenhouse using the pseudo-cereal Chenopodium quinoa. The three factors used in the study were (I) type of biochar addition ("aged", "fresh", or zero BC), (II) addition of compost and (III) low and high application rates of a full NPK-fertilizer (equivalent to 28 and 140 kg N ha-1, NPK + micronutrients) in several doses. The growth medium was a poor loamy sand. Biochars and compost were all added at a rate of 2% (w/w) to the soil. From the start there was a considerable difference between the growth of Quinoa with the fresh compared to the aged biochar. The fresh biochar produced the well-known reduction in plant growth compared to the unamended control. This reduction was alleviated to a certain extent by the addition of either compost and/or increased fertilization. In contrast the co-composted biochar always resulted in a highly significant stimulation of the Quinoa yield (roots, shoots, inflorescences). This stimulation was most pronounced when the growth conditions were the most unfavorable (no compost addition + low fertilization: aged BC 305% versus fresh BC 61% of zero-BC). The stimulation was least pronounced in the treatment where the growth conditions were most favorable (compost addition + high fertilization). However, despite the higher fertility and higher nitrate values the mixtures with the composted biochar did not show higher N2O emissions. Reasons for the strong significant change in plant growth promotion, i.e. changes on the biochar surfaces that occur during the composting, will be discussed. Fischer D, Glaser B (2012) Synergisms between compost and biochar for sustainable soil amelioration. In: Management of Organic Waste. (eds Sunil K, Bharti A), ISBN 978-953-307-925-7, Chapter 10, pp. 167-198.

Biochar filters reduced the toxic effects of nickel on tomato (Lycopersicon esculentum L.) grown in nutrient film technique hydroponic system.

PubMed

Mosa, Ahmed; El-Banna, Mostafa F; Gao, Bin

2016-04-01

This work used the nutrient film technique to evaluate the role of biochar filtration in reducing the toxic effects of nickel (Ni(2+)) on tomato growth. Three hydroponic treatments: T1 (control), T2 (with Ni(2+)), and T3 (with Ni(2+) and biochar) were used in the experiments. Scanning electron microscopy equipped with energy dispersive X-ray spectroscopy and Fourier transform spectroscopy was used to characterize the pre- and post-treatment biochar samples. The results illustrated that precipitation, ion exchange, and complexation with surface functional groups were the potential mechanisms of Ni(2+) removal by biochar. In comparison to the control, the T2 treatment showed severe Ni-stress with alterations in cell wall structure, distortions in cell nucleus, disturbances in mitochondrial system, malformations in stomatal structure, and abnormalities in chloroplast structure. The biochar filters in T3 treatment reduced dysfunctions of cell organelles in root and shoot cells. Total chlorophyll concentration decreased by 41.6% in T2 treatment. This reduction, however, was only 20.8% due to the protective effect of the biochar filters. The presence of Ni(2+) in the systems reduced the tomato fruit yield 58.5% and 31.9% in T2 and T3, respectively. Nickel concentrations reached the toxic limit in roots, shoots, and fruits in T2, which were not observed in T3. Biochar filters in T3 also minimized the dramatic reductions in nutrients concentration in roots, shoots, and fruits, which occurred in T2 treatment due to the severe Ni-stress. Findings from this work suggested that biochar filters can be used on farms as a safeguard for wastewater irrigation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Contrasting effects of biochar versus manure on soil microbial communities and enzyme activities in an Aridisol.

PubMed

Elzobair, Khalid A; Stromberger, Mary E; Ippolito, James A; Lentz, Rodrick D

2016-01-01

Biochar can increase microbial activity, alter microbial community structure, and increase soil fertility in arid and semi-arid soils, but at relatively high rates that may be impractical for large-scale field studies. This contrasts with organic amendments such as manure, which can be abundant and inexpensive if locally available, and thus can be applied to fields at greater rates than biochar. In a field study comparing biochar and manure, a fast pyrolysis hardwood biochar (22.4 Mg ha(-1)), dairy manure (42 Mg ha(-1) dry wt), a combination of biochar and manure at the aforementioned rates, or no amendment (control) was applied to an Aridisol (n=3) in fall 2008. Plots were annually cropped to corn (Zea maize L.). Surface soils (0-30 cm) were sampled directly under corn plants in late June 2009 and early August 2012, and assayed for microbial community fatty acid methyl ester (FAME) profiles and six extracellular enzyme activities involved in soil C, N, and P cycling. Arbuscular mycorrhizal (AM) fungal colonization was assayed in corn roots in 2012. Biochar had no effect on microbial biomass, community structure, extracellular enzyme activities, or AM fungi root colonization of corn. In the short-term, manure amendment increased microbial biomass, altered microbial community structure, and significantly reduced the relative concentration of the AM fungal biomass in soil. Manure also reduced the percent root colonization of corn by AM fungi in the longer-term. Thus, biochar and manure had contrasting short-term effects on soil microbial communities, perhaps because of the relatively low application rate of biochar. Copyright © 2015 Elsevier Ltd. All rights reserved.

Nitrogen enrichment potential of biochar in relation to pyrolysis temperature and feedstock quality.

PubMed

Jassal, Rachhpal S; Johnson, Mark S; Molodovskaya, Marina; Black, T Andrew; Jollymore, Ashlee; Sveinson, Kelly

2015-04-01

Nitrogen (N) enrichment of biochar from both inorganic and organic waste N sources has the potential to add economic and environmental value through its use as a slow release N fertilizer. We investigated the sorption of N by, and its release from, biochar made at pyrolysis temperatures of 400, 500 and 600 °C from three feedstocks: poultry litter (PL with a carbon (C) to N ratio (C:N) of 14), softwood chips of spruce-pine-fir (SPF with a C:N of 470), and a 50:50 mixture of PL and SPF (PL/SPF). The prepared biochars were enriched with ammonium nitrate (AN) and urea ammonium nitrate (UAN). PL biochars had the lowest C content (50-56% C), but the highest pH (9.3-9.9), electrical conductivity (EC, 780-960 dS m(-1)), cation exchange capacity (CEC, 40-46 cmol kg(-1)), and N content (3.3-4.5%). While N content and hydrogen (H) to C atomic ratio (H:C) decreased with increasing pyrolysis temperature irrespective of the feedstock used, both pH and EC slightly increased with pyrolysis temperature for all feedstocks. The PL and SPF biochars showed similar H:C and also similar N sorption and N release at all pyrolysis temperatures. These biochars sorbed up to 5% N by mass, irrespective of the source of N. However, PL/SPF biochar performed poorly in sorbing N from either AN or UAN. Biochar H:C was found to be unrelated to N sorption rates, suggesting that physical adsorption on active surfaces was the main mechanism of N sorption in these biochars. There were minor differences between N sorbed from NO3-N and NH4-N among different biochars. Very small amounts of sorbed N (0.2-0.4 mg N g(-1) biochar) was released when extracted with 1 M KCl solution, indicating that the retained N was strongly held in complex bonds, more so for NH4-N because the release of NO3-N was 3-4 times greater than that of NH4-N. NH4-N sorption far exceeded the effective CEC of the biochars, thereby suggesting that most of the sorption may be due to physical entrapment of NH4(+) in biochar pores. The results of this study suggest that biochar can be used to remove excess N from poultry and dairy manure and be a good mitigation option for reducing N leaching and gaseous losses. Copyright © 2015 Elsevier Ltd. All rights reserved.

Biochar and compost as amendments in copper-enriched vineyard soils - stabilization or mobilization of copper?

NASA Astrophysics Data System (ADS)

Soja, Gerhard; Fristak, Vladimir; Wimmer, Bernhard; Bell, Stephen; Chamier Glisczinski, Julia; Pardeller, Georg; Dersch, Georg; Rosner, Franz; Wenzel, Walter; Zehetner, Franz

2016-04-01

Copper is an important ingredient for several fungicides that have been used in agriculture. For organic viticulture, several diseases as e.g. downy mildew (Plasmopara viticola) can only be antagonized with Cu-containing fungicides. This long-lasting dependence on Cu-fungicides has led to a gradual Cu enrichment of vineyard soils in traditional wine-growing areas, occasionally exceeding 300 mg/kg. Although these concentrations do not affect the vines or wine quality, they may impair soil microbiological functions in the top soil layer or the root growth of green cover plants. Therefore measures are demanded that reduce the bioavailability of copper, thereby reducing the ecotoxicological effects. The use of biochar and compost as soil amendment has been suggested as a strategy to immobilize Cu and reduce the exchangeable fractions. This study consisted of lab and greenhouse experiments that were designed to test the sorption and desorption behavior of copper in vineyard soils with or without biochar and/or compost as soil amendment. Slightly acidic soils (pH<6) showed a clearer biochar-induced immobilization of copper with biochar than neutral or alkaline soils. The analyses of leachate waters of microlysimeter experiments showed that the biochar effects were more evident for a reduction of the ionic form Cu2+ than for total soluble copper, even in alkaline soils. Biochar modified with citric or tartaric acid did not significantly decrease the solubility of copper based on total dissolved concentrations although CEC was higher than in unmodified biochar. Treatments consisting of compost only or that had an equal amount of compost and biochar rather had a mobilizing effect on biochar. Sorption experiments with different DOC concentrations and biochar, however, showed a positive effect on copper sorption. Apparently in vineyard soils the predisposition to form organic-Cu-complexes may outbalance the binding possibilities of these complexes to biochar, occasionally resulting in enhanced mobilization. Presumably immobilization of copper with biochar would work best in acidic soils low in organic carbon and with low or no compost addition although this might be at odds with standard vineyard soil management practices.

Stability of polyvinyl alcohol-coated biochar nanoparticles in brine

NASA Astrophysics Data System (ADS)

Griffith, Christopher; Daigle, Hugh

2017-01-01

This paper reports on the dispersion stability of 150 nm polyvinyl alcohol coated biochar nanoparticles in brine water. Biochar is a renewable, carbon based material that is of significant interest for enhanced oil recovery operations primarily due to its wide ranging surface properties, low cost of synthesis, and low environmental toxicity. Nanoparticles used as stabilizing agents for foams (and emulsions) or in nanofluids have emerged as potential alternatives to surfactants for subsurface applications due to their improved stability at reservoir conditions. If, however, the particles are not properly designed, they are susceptible to aggregation because of the high salinity brines typical of oil and gas reservoirs. Attachment of polymers to the nanoparticle surface, through covalent bonds, provides steric stabilization, and is a necessary step. Our results show that as the graft density of polyvinyl alcohol increases, so too does the stability of nanoparticles in brine solutions. A maximum of 34 wt% of 50,000 Da polyvinyl alcohol was grafted to the particle surface, and the size of the particles was reduced from 3500 nm (no coating) to 350 nm in brine. After 24 h, the particles had a size of 500 nm, and after 48 h completely aggregated. 100,000 Da PVA coated at 24 wt% on the biochar particles were stable in brine for over 1 month with no change in mean particle size of 330 nm.

Effects of modified biochar on rhizosphere microecology of rice (Oryza sativa L.) grown in As-contaminated soil.

PubMed

Liu, Shusi; Lu, Yixin; Yang, Chen; Liu, Chuanping; Ma, Lin; Dang, Zhi

2017-10-01

Biochar was carbon-rich and generated by high-temperature pyrolysis of biomass under oxygen-limited conditions. Due to the limitations of surface functional groups and the weakness of surface activity in the field of environmental remediation, the raw biochar frequently was chemically modified to improve its properties with a new performance. In this study, a kind of high-efficiency and low-cost amino biochar modified by nano zero-valent iron (ABC/NZVI) was synthesized and applied to paddy soil contaminated with arsenic (As). Dynamic changes of soil properties, arsenic speciations and rhizosphere microbial communities have been investigated over the whole growth period of rice plants. Pot experiments revealed that the ABC/NZVI could decrease the arsenic concentration in rice straw by 47.9% and increase the content of nitrogen in rice straw by 47.2%. Proportion of Geobacter in soil with ABC/NZVI treatment increased by 175% in tillering period; while Nitrososphaera decreased by 61 and 20% in tillering and maturity, respectively, compared to that of control. ABC/NZVI promotes arsenic immobilization in rhizosphere soil and precipitation on root surface and reduces arsenic accumulation in rice. At the same time, ABC/NZVI would inhibit Nitrososphaera which is related to ammonia oxidation process, and it would have a promising potential as soil amendment to reduce nitrogen loss probably.

Soil respiration characteristics in different land uses and response of soil organic carbon to biochar addition in high-latitude agricultural area.

PubMed

Ouyang, Wei; Geng, Xiaojun; Huang, Wejia; Hao, Fanghua; Zhao, Jinbo

2016-02-01

The farmland tillage practices changed the soil chemical properties, which also impacted the soil respiration (R s ) process and the soil carbon conservation. Originally, the farmland in northeast China had high soil carbon content, which was decreased in the recent decades due to the tillage practices. To better understand the R s dynamics in different land use types and its relationship with soil carbon loss, soil samples at two layers (0-15 and 15-30 cm) were analyzed for organic carbon (OC), total nitrogen (TN), total phosphorus (TP), total carbon (TC), available nitrogen (AN), available phosphorus (AP), soil particle size distribution, as well as the R s rate. The R s rate of the paddy land was 0.22 (at 0-15 cm) and 3.01 (at 15-30 cm) times of the upland. The average concentrations of OC and clay content in cultivated areas were much lower than in non-cultivated areas. The partial least squares analysis suggested that the TC and TN were significantly related to the R s process in cultivated soils. The upland soil was further used to test soil CO2 emission response at different biochar addition levels during 70-days incubation. The measurement in the limited incubation period demonstrated that the addition of biochar improved the soil C content because it had high concentration of pyrogenic C, which was resistant to mineralization. The analysis showed that biochar addition can promote soil OC by mitigating carbon dioxide (CO2) emission. The biochar addition achieved the best performance for the soil carbon conservation in high-latitude agricultural area due to the originally high carbon content.

The influence of biochar type on long-term stabilization for Cd and Cu in contaminated paddy soils.

PubMed

Li, Hongying; Ye, Xinxin; Geng, Zhigang; Zhou, Hongjian; Guo, Xisheng; Zhang, Yunxia; Zhao, Huijun; Wang, Guozhong

2016-03-05

Long-term effect of biochar on PTEs (potential toxic elements) immobilization depends upon biochar own property and its aging process in soil. To understand the role of biachar type on PTEs stabilization, two types of biochar, corn-straw-derived biochar (CB) and hardwood-derived biochar (HB), were compared for their efficacy in achieving a stable decrease in the bio-availability of Cd and Cu in soils. The 3-year pot-culture experiment showed that HB reduced the concentration of CaCl2-extractable Cd and Cu by 57.9 and 63.8% in soil, and Cd and Cu uptake by 63.6 and 56.3% in rice tissue respectively, in the first year, whereas these values increased in the next two years. On the other hand, CB decreased these values steadily year by year. At the end of the 3 years, CB at 5% level had lowered the levels of CaCl2-extractable Cd and Cu by 53.6 and 66.8%, respectively. These variations between CB and HB were due to the differences in the way the two types of biochar age in the soil. The aging process was simulated in the laboratory, and the XPS results showed that the oxidization of the biochars introduced more oxygen-containing groups (especially carboxyl) on the surface of CB than HB, leading to a correspondingly greater number of oxygenated binding sites for Cd and Cu in the case of CB. The content of lignin was the major factor resulting in the variation of oxidation degree in two biochars. These results suggest that it is important to select the right kind of biochar to stably decrease the bio-availability of potential toxic elements (Cd and Cu) in contaminated soils. Copyright © 2015 Elsevier B.V. All rights reserved.

Relating physical and chemical properties of four different biochars and their application rate to biomass production of Lolium perenne on a Calcic Cambisol during a pot experiment of 79 days.

PubMed

de la Rosa, José M; Paneque, Marina; Miller, Ana Z; Knicker, Heike

2014-11-15

Three pyrolysis biochars (B1: wood, B2: paper-sludge, B3: sewage-sludge) and one kiln-biochar (B4: grapevine wood) were characterized by determining different chemical and physical properties which were related to the germination rates and to the plant biomass production during a pot experiment of 79 days in which a Calcic Cambisol from SW Spain was amended with 10, 20 and 40 t ha(-1) of the four biochars. Biochar 1, B2 and B4 revealed comparable elemental composition, pH, water holding capacity and ash content. The H/C and O/C atomic ratios suggested high aromaticity of all biochars, which was confirmed by (13)C solid-state NMR spectroscopy. The FT-IR spectra confirmed the aromaticity of all the biochars as well as several specific differences in their composition. The FESEM-EDS distinguished compositional and structural differences of the studied biochars such as macropores on the surface of B1, collapsed structures in B2, high amount of mineral deposits (rich in Al, Si, Ca and Fe) and organic phases in B3 and vessel structures for B4. Biochar amendment improved germination rates and soil fertility (excepting for B4), and had no negative pH impact on the already alkaline soil. Application of B3, the richest in minerals and nitrogen, resulted in the highest soil fertility. In this case, increase of the dose went along with an enhancement of plant production. Considering costs due to production and transport of biochar, for all used chars with the exception of B3, the application of 10 t ha(-1) turned out as the most efficient for the crop and soil used in the present incubation experiment. Copyright © 2014 Elsevier B.V. All rights reserved.

Effects of biochar produced from different feedstocks on soil properties and sunflower growth

NASA Astrophysics Data System (ADS)

Alburquerque, J. A.; Calero, J. M.; Villar, R.; Barrón, V.; Torrent, J.; del Campillo, M. C.; Gallardo, A.

2012-04-01

The use of biochar obtained from biomass pyrolysis as a soil amendment has potential benefits, such as reduction in gas emissions, increase in soil carbon sequestration and improvements in soil fertility and crop yield. These constitute a great incentive for the implementation of biochar-based strategies, which could contribute to improvement of the sustainability of agricultural systems. However, to date, the results of research studies show great variability as a result of differences in both the raw materials and the pyrolysis conditions used to produce biochar, as well as in the experimental setting (crop, soil type, pedo-climatic conditions, etc.). The aim of this study was to evaluate the effects of five types of biochar produced from representative agricultural and forestry wastes (olive husk, almond shell, wheat straw, pine woodchips and olive tree prunings), and applied to soil at different rates, on soil properties and sunflower (Helianthus annuus L.) growth. The biochars had a high organic matter content, alkaline pH, variable soluble salt content and non-phytotoxic properties. The addition of biochar to soil increased pH, electrical conductivity and water retention capacity, and decreased soil bulk density compared to control (unamended soil). However, these effects differed depending on biochar type. In contrast, no consistent effects on sunflower growth variables were observed due to the addition of biochar: increases were observed in some variables (plant dry weight, leaf area and height), but these increases were, in general, not statistically significant when compared to the unamended soil. This can be explained by the nature of biochar, being rich in carbon but relatively poor in nutrients. In summary, our results indicate that biochar is capable of improving soil properties which can impact positively on soil-plant water relations, without negative effects on sunflower growth, and therefore it is suitable for use as a long-term carbon sink in agricultural soils, with both agricultural and environmental benefits.

Enhanced Fenton-like Degradation of Trichloroethylene by Hydrogen Peroxide Activated with Nanoscale Zero Valent Iron Loaded on Biochar

PubMed Central

Yan, Jingchun; Qian, Linbo; Gao, Weiguo; Chen, Yun; Ouyang, Da; Chen, Mengfang

2017-01-01

Composite of nanoscale Zero Valent Iron (nZVI) loaded on Biochar (BC) was prepared and characterized as hydrogen peroxide (H2O2) activator for the degradation of trichloroethylene (TCE). nZVI is homogeneously loaded on lamellarly structured BC surfaces to form nZVI/BC with specific surface area (SBET) of 184.91 m2 g−1, which can efficiently activate H2O2 to achieve TCE degradation efficiency of 98.9% with TOC removal of 78.2% within 30 min under the conditions of 0.10 mmol L−1 TCE, 1.13 g L−1 nZVI/BC and 1.50 mmol L−1 H2O2. Test results from the Electron Spin Resonance (ESR) measurement and coumarin based fluorescent probe technology indicated that ∙OH radicals were the dominant species responsible for the degradation of TCE within the nZVI/BC-H2O2 system. Activation mechanism of the redox action of Fe2+/Fe3+ generated under both aerobic and anaerobic conditions from nZVI and single electron transfer process from BC surface bound C–OH to H2O2 promoted decomposition of H2O2 into ∙OH radicals was proposed. PMID:28230207

Enhanced Fenton-like Degradation of Trichloroethylene by Hydrogen Peroxide Activated with Nanoscale Zero Valent Iron Loaded on Biochar

NASA Astrophysics Data System (ADS)

Yan, Jingchun; Qian, Linbo; Gao, Weiguo; Chen, Yun; Ouyang, Da; Chen, Mengfang

2017-02-01

Composite of nanoscale Zero Valent Iron (nZVI) loaded on Biochar (BC) was prepared and characterized as hydrogen peroxide (H2O2) activator for the degradation of trichloroethylene (TCE). nZVI is homogeneously loaded on lamellarly structured BC surfaces to form nZVI/BC with specific surface area (SBET) of 184.91 m2 g-1, which can efficiently activate H2O2 to achieve TCE degradation efficiency of 98.9% with TOC removal of 78.2% within 30 min under the conditions of 0.10 mmol L-1 TCE, 1.13 g L-1 nZVI/BC and 1.50 mmol L-1 H2O2. Test results from the Electron Spin Resonance (ESR) measurement and coumarin based fluorescent probe technology indicated that •OH radicals were the dominant species responsible for the degradation of TCE within the nZVI/BC-H2O2 system. Activation mechanism of the redox action of Fe2+/Fe3+ generated under both aerobic and anaerobic conditions from nZVI and single electron transfer process from BC surface bound C-OH to H2O2 promoted decomposition of H2O2 into •OH radicals was proposed.

Conocarpus biochar as a soil amendment for reducing heavy metal availability and uptake by maize plants.

PubMed

Al-Wabel, Mohammad I; Usman, Adel R A; El-Naggar, Ahmed H; Aly, Anwar A; Ibrahim, Hesham M; Elmaghraby, Salem; Al-Omran, Abdulrasoul

2015-07-01

The objective of this study was to assess the use of Concarpus biochar as a soil amendment for reducing heavy metal accessibility and uptake by maize plants (Zea mays L.). The impacts of biochar rates (0.0, 1.0, 3.0, and 5.0% w/w) and two soil moisture levels (75% and 100% of field capacity, FC) on immobilization and availability of Fe, Mn, Zn, Cd, Cu and Pb to maize plants as well as its application effects on soil pH, EC, bulk density, and moisture content were evaluated using heavy metal-contaminated soil collected from mining area. The biochar addition significantly decreased the bulk density and increased moisture content of soil. Applying biochar significantly reduced NH4OAc- or AB-DTPA-extractable heavy metal concentrations of soils, indicating metal immobilization. Conocarpus biochar increased shoot dry biomass of maize plants by 54.5-102% at 75% FC and 133-266% at 100% FC. Moreover, applying biochar significantly reduced shoot heavy metal concentrations in maize plants (except for Fe at 75% FC) in response to increasing application rates, with a highest decrease of 51.3% and 60.5% for Mn, 28% and 21.2% for Zn, 60% and 29.5% for Cu, 53.2% and 47.2% for Cd at soil moisture levels of 75% FC and 100% FC, respectively. The results suggest that biochar may be effectively used as a soil amendment for heavy metal immobilization and in reducing its phytotoxicity.

Conocarpus biochar as a soil amendment for reducing heavy metal availability and uptake by maize plants

PubMed Central

Al-Wabel, Mohammad I.; Usman, Adel R.A.; El-Naggar, Ahmed H.; Aly, Anwar A.; Ibrahim, Hesham M.; Elmaghraby, Salem; Al-Omran, Abdulrasoul

2014-01-01

The objective of this study was to assess the use of Concarpus biochar as a soil amendment for reducing heavy metal accessibility and uptake by maize plants (Zea mays L.). The impacts of biochar rates (0.0, 1.0, 3.0, and 5.0% w/w) and two soil moisture levels (75% and 100% of field capacity, FC) on immobilization and availability of Fe, Mn, Zn, Cd, Cu and Pb to maize plants as well as its application effects on soil pH, EC, bulk density, and moisture content were evaluated using heavy metal-contaminated soil collected from mining area. The biochar addition significantly decreased the bulk density and increased moisture content of soil. Applying biochar significantly reduced NH4OAc- or AB-DTPA-extractable heavy metal concentrations of soils, indicating metal immobilization. Conocarpus biochar increased shoot dry biomass of maize plants by 54.5–102% at 75% FC and 133–266% at 100% FC. Moreover, applying biochar significantly reduced shoot heavy metal concentrations in maize plants (except for Fe at 75% FC) in response to increasing application rates, with a highest decrease of 51.3% and 60.5% for Mn, 28% and 21.2% for Zn, 60% and 29.5% for Cu, 53.2% and 47.2% for Cd at soil moisture levels of 75% FC and 100% FC, respectively. The results suggest that biochar may be effectively used as a soil amendment for heavy metal immobilization and in reducing its phytotoxicity. PMID:26150758

Recent studies on activated carbons and fly ashes from Turkish resources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ayhan Demirbas; Gulsin Arslan; Erol Pehlivan

2006-05-15

This article deals with adsorptive properties of activated carbons (ACs) and fly ashes from Turkish coal and biomass resources. ACs because of their high surface area, microporous character and the chemical nature of their surface have been considered potential adsorbents for the removal of heavy metals from industrial wastewater. Pyrolysis is an established process method for preparation of activated carbon from biomass. The bio-char is can be used as AC. The adsorption properties of ACs were strictly defined by the physicochemical nature of their surface and their texture, i.e., pore volume, pore size distribution, surface area. It is well knownmore » that the pH of the solution-adsorbant mixture is an important variable in the adsorption process. Fly ash has the highest adsorption capacity (198.2 mg/g for Cd(II)). Almond shell AC has the lowest adsorption capacity (2.7 mg/g).« less

Performance, kinetics, and equilibrium of methylene blue adsorption on biochar derived from eucalyptus saw dust modified with citric, tartaric, and acetic acids.

PubMed

Sun, Lei; Chen, Dongmei; Wan, Shungang; Yu, Zebin

2015-12-01

Biochar derived from eucalyptus saw dust modified with citric, tartaric, and acetic acids at low temperatures was utilized as adsorbent to remove methylene blue (MB) from aqueous solutions. Fourier transform infrared spectroscopy analysis showed that the carboxyl group was introduced on the biochar surface. Adsorption experiment data indicated that eucalyptus saw dust modified with citric acid showed higher MB adsorption efficiency than that modified with tartaric and acetic acids. Pseudo-second-order kinetics was the most suitable model for describing MB adsorption on biochar compared with pseudo-first-order, Elovich, and intraparticle diffusion models. The calculated values of ΔG(0) and ΔH(0) indicated the spontaneous and endothermic nature of the adsorption process. MB adsorption on biochar followed the Langmuir isotherm. The maximum adsorption capacities for eucalyptus saw dust modified with citric, tartaric, and acetic acids were 178.57, 99.01, and 29.94 mg g(-1), respectively, at 35°C. Copyright © 2015 Elsevier Ltd. All rights reserved.

Using Biochar composts for improving sandy vineyard soils while reducing the risk of

NASA Astrophysics Data System (ADS)

Kammann, Claudia; Mengel, Jonathan; Mohr, Julia; Muskat, Stefan; Schmidt, Hans-Peter; Löhnertz, Otmar

2016-04-01

In recent years, biochar has increasingly been discussed as an option for sustainable environmentalmanagement, combining C sequestration with the aim of soil fertility improvement. Biochar has shownpositive effects in viticulture before (Genesio et al. 2015) which were largely attributed to improved water supply to the plants. However, in fertile temperate soils, the use of pure, untreated biochar does not guarantee economic benefits on the farm level (Ruysschaert et al., 2016). Hence, recent approaches started introducing biochar in management of nutrient-rich agricultural waste, e.g. in compost production (Kammann et al. 2015). Compost is frequently used in German vineyards for humus buildup and as a slow-release organic fertilizer. This, and increasingly mild, precipitation-rich winters, promoting mineralization, increase the risk of unwanted nitrate leaching losses into surface and ground waters during winter. To investigate if biochar pure, or biochar-compost mixtures and -products may have the potential to reduce nitrate leaching, we set up the following experiment: Either 30 or 60 t ha-1 of the following additives were mixed into the top 30 cm of sandy soil in large (120 L) containers, and planted with oneRiesling grapevine (Clone 198-30 GM) per container: Control (no addition), pure woody biochar, pure compost, biochar-compost (produced from the same organic feedstock than the compost, with 20 vol. - % of a woody biochar added), and pure compost plus pure biochar (same mixing ratio as in the former product). Once monthly, containers were exposed to simulated heavy rainfall that caused drainage. Leachates were collected from an outlet at the bottom of the containers, and analyzed for nutrients. The nutrient-rich additives containing compost all improved grape biomass and yield, most markedly pure compost and biochar-compost; same amendments were not significantly different. However,while the addition of the lower amount (30 t ha-1) of compost reduced nitrate leaching compared to the control (where nearly all mineral N was lost), the larger application amount in pure compost caused rising nitrate loss rates, likely due to compost mineralization. Interestingly, this was not the case when biochar was included, either co-composted or mixed into the substrates afterwards. However, after three years, the biochar-compost treatment still showed the highest grape yield of all treatments, while the treatment with biochar mixed in after compost production did not have the same effect. The results suggest that biochar-composts, for example produced from vine making residue and greenwaste, may reduce the risk of nitrate leaching while increasing the soil organic content more permanently than other amendments. Genesio, L., Miglietta, F., Baronti, S., Vaccari, F.P., 2015. Biochar increases vineyard Productivity without affecting grape quality: Results from a four years field experiment in Tuscany. Agriculture, Ecosystems & Environment 201, 20-25. Kammann, C.I., Schmidt, H.-P., Messerschmidt, N., Linsel, S., Steffens, D., Müller, C., Koyro, H.-W., Conte, P., Joseph, S., 2015. Plant growth improvement mediated by nitrate capture in cocomposted biochar. Scientific Reports 5, doi: 10.1038/srep11080. Ruysschaert, G., Nelissen, V., Postma, R., Bruun, E., O'Toole, A., Hammond, J., Rödger, J.-M.,Hylander, L., Kihlberg, T., Zwart, K., Hauggaard-Nielsen, H., Shackley, S., 2016. Field applications of pure biochar in the North Sea region and across Europe, in: Shackley, S.,Ruysschaert, G., Zwart, K., Glaser, B. (Eds.), Biochar in European Soils and Agriculture - Science and Practice. Routhledge, Oxon, UK and New York, USA.

Sludge Biochar Amendment and Alfalfa Revegetation Improve Soil Physicochemical Properties and Increase Diversity of Soil Microbes in Soils from a Rare Earth Element Mining Wasteland

PubMed Central

Inubushi, Kazuyuki; Liang, Jian; Zhu, Sipin; Wei, Zhenya; Guo, Xiaobin; Luo, Xianping

2018-01-01

Long-term unregulated mining of ion-adsorption clays (IAC) in China has resulted in severe ecological destruction and created large areas of wasteland in dire need of rehabilitation. Soil amendment and revegetation are two important means of rehabilitation of IAC mining wasteland. In this study, we used sludge biochar prepared by pyrolysis of municipal sewage sludge as a soil ameliorant, selected alfalfa as a revegetation plant, and conducted pot trials in a climate-controlled chamber. We investigated the effects of alfalfa revegetation, sludge biochar amendment, and their combined amendment on soil physicochemical properties in soil from an IAC mining wasteland as well as the impact of sludge biochar on plant growth. At the same time, we also assessed the impacts of these amendments on the soil microbial community by means of the Illumina Miseq sequences method. Results showed that alfalfa revegetation and sludge biochar both improved soil physicochemical properties and microbial community structure. When alfalfa revegetation and sludge biochar amendment were combined, we detected additive effects on the improvement of soil physicochemical properties as well as increases in the richness and diversity of bacterial and fungal communities. Redundancy analyses suggested that alfalfa revegetation and sludge biochar amendment significantly affected soil microbial community structure. Critical environmental factors consisted of soil available K, pH, organic matter, carbon–nitrogen ratio, bulk density, and total porosity. Sludge biochar amendment significantly promoted the growth of alfalfa and changed its root morphology. Combining alfalfa the revegetation with sludge biochar amendment may serve to not only achieve the revegetation of IAC mining wasteland, but also address the challenge of municipal sludge disposal by making the waste profitable. PMID:29751652

Sludge Biochar Amendment and Alfalfa Revegetation Improve Soil Physicochemical Properties and Increase Diversity of Soil Microbes in Soils from a Rare Earth Element Mining Wasteland.

PubMed

Luo, Caigui; Deng, Yangwu; Inubushi, Kazuyuki; Liang, Jian; Zhu, Sipin; Wei, Zhenya; Guo, Xiaobin; Luo, Xianping

2018-05-11

Long-term unregulated mining of ion-adsorption clays (IAC) in China has resulted in severe ecological destruction and created large areas of wasteland in dire need of rehabilitation. Soil amendment and revegetation are two important means of rehabilitation of IAC mining wasteland. In this study, we used sludge biochar prepared by pyrolysis of municipal sewage sludge as a soil ameliorant, selected alfalfa as a revegetation plant, and conducted pot trials in a climate-controlled chamber. We investigated the effects of alfalfa revegetation, sludge biochar amendment, and their combined amendment on soil physicochemical properties in soil from an IAC mining wasteland as well as the impact of sludge biochar on plant growth. At the same time, we also assessed the impacts of these amendments on the soil microbial community by means of the Illumina Miseq sequences method. Results showed that alfalfa revegetation and sludge biochar both improved soil physicochemical properties and microbial community structure. When alfalfa revegetation and sludge biochar amendment were combined, we detected additive effects on the improvement of soil physicochemical properties as well as increases in the richness and diversity of bacterial and fungal communities. Redundancy analyses suggested that alfalfa revegetation and sludge biochar amendment significantly affected soil microbial community structure. Critical environmental factors consisted of soil available K, pH, organic matter, carbon⁻nitrogen ratio, bulk density, and total porosity. Sludge biochar amendment significantly promoted the growth of alfalfa and changed its root morphology. Combining alfalfa the revegetation with sludge biochar amendment may serve to not only achieve the revegetation of IAC mining wasteland, but also address the challenge of municipal sludge disposal by making the waste profitable.

Biochar application for the remediation of salt-affected soils: Challenges and opportunities.

PubMed

Saifullah; Dahlawi, Saad; Naeem, Asif; Rengel, Zed; Naidu, Ravi

2018-06-01

Soil salinization and sodification are two commonly occurring major threats to soil productivity in arable croplands. Salt-affected soils are found in >100 countries, and their distribution is extensive and widespread in arid and semi-arid regions of the world. In order to meet the challenges of global food security, it is imperative to bring barren salt-affected soils under cultivation. Various inorganic and organic amendments are used to reclaim the salt-affected lands. The selection of a sustainable ameliorant is largely determined by the site-specific geographical and soil physicochemical parameters. Recently, biochar (solid carbonaceous residue, produced under oxygen-free or oxygen-limited conditions at temperatures ranging from 300 to 1000°C) has attracted considerable attention as a soil amendment. An emerging pool of knowledge shows that biochar addition is effective in improving physical, chemical and biological properties of salt-affected soils. However, some studies have also found an increase in soil salinity and sodicity with biochar application at high rates. Further, the high cost associated with production of biochar and high application rates remains a significant challenge to its widespread use in areas affected by salinity and sodicity. Moreover, there is relatively limited information on the long-term behavior of salt-affected soils subjected to biochar applications. The main objective of the present paper was to review, analyze and discuss the recent studies investigating a role of biochar in improving soil properties and plant growth in salt-affected soils. This review emphasizes that using biochar as an organic amendment for sustainable and profitable use of salt-affected soils would not be practicable as long as low-cost methods for the production of biochar are not devised. Copyright © 2017 Elsevier B.V. All rights reserved.

Efficient removal of crystal violet using Fe3O4-coated biochar: the role of the Fe3O4 nanoparticles and modeling study their adsorption behavior

NASA Astrophysics Data System (ADS)

Sun, Pengfei; Hui, Cai; Azim Khan, Rashid; Du, Jingting; Zhang, Qichun; Zhao, Yu-Hua

2015-07-01

Biochar shows great promise for use in adsorbing pollutants. However, a process for enhancing its adsorption capacity and re-collection efficiency is yet to be further developed. Hence, in this study, we developed a type of biochar coated with magnetic Fe3O4 nanoparticles (i.e., magnetic biochar (MBC)) and assessed its use for crystal violet (CV) adsorption as well as its recycling potential. The coating of Fe3O4 nanoparticles, which was not only on the surface, but also in the interior of biochar, performed two functions. Firstly, it produced a saturation magnetization of 61.48 emu/g, which enabled the biochar being efficiently re-collected using a magnet. Secondly, it significantly enhanced the adsorption capacity of the biochar (from 80.36 to 99.19 mg/g). The adsorption capacity of the MBC was determined to be the largest by so far (349.40 mg/g) for an initial CV concentration of 400 mg/L, pH of 6.0, and temperature of 40 °C, and the adsorption capacity of re-collected MBC was 73.31 mg/g. The adsorption of CV by the MBC was found to be a spontaneous and endothermic physical process in which the intraparticle diffusion was the limiting step. These findings inspire us to use other similar materials to tackle the menace of pollutions.

Bioaccumulation of CeO2 Nanoparticles by Earthworms in Biochar-Amended Soil: A Synchrotron Microspectroscopy Study.

PubMed

Servin, Alia D; Castillo-Michel, Hiram; Hernandez-Viezcas, Jose A; De Nolf, Wout; De La Torre-Roche, Roberto; Pagano, Luca; Pignatello, Joseph; Uchimiya, Minori; Gardea-Torresdey, Jorge; White, Jason C

2018-01-11

The interactions of nanoparticles (NPs) with biochar and soil components may substantially influence NP availability and toxicity to biota. In the present study, earthworms (Eisenia fetida) were exposed for 28 days to a residential or agricultural soil amended with 0-2000 mg of CeO 2 NP/kg and with biochar (produced by the pyrolysis of pecan shells at 350 and 600 °C) at various application rates [0-5% (w/w)]. After 28 days, earthworms were depurated and analyzed for Ce content, moisture content, and lipid peroxidation. The results showed minimal toxicity to the worms; however, biochar (350 or 600 °C) was the dominant factor, accounting for 94 and 84% of the variance for the moisture content and lipid peroxidation, respectively, in the exposed earthworms. For both soils with 1000 mg of CeO 2 /kg at 600 °C, biochar significantly decreased the accumulation of Ce in the worm tissues. Amendment with 350 °C biochar had mixed responses on Ce uptake. Analysis by micro X-ray fluorescence (μ-XRF) and micro X-ray absorption near edge structure (μ-XANES) was used to evaluate Ce localization, speciation, and persistence in CeO 2 - and biochar-exposed earthworms after depuration for 12, 48, and 72 h. Earthworms from the 500 mg of CeO 2 /kg and 0% biochar treatments eliminated most Ce after a 48 h depuration period. However, in the same treatment and with 5% BC-600 (biochar pyrolysis temperature of 600 °C), ingested biochar fragments (∼50 μm) with Ce adsorbed to the surfaces were retained in the gut after 72 h. Additionally, Ce remained in earthworms from the 2000 mg of CeO 2 /kg and 5% biochar treatments after depuration for 48 h. Analysis by μ-XANES showed that, within the earthworm tissues, Ce remained predominantly as Ce 4+ O 2 , with only few regions (2-3 μm 2 ) where it was found in the reduced form (Ce 3+ ). The present findings highlight that soil and biochar properties have a significant influence in the internalization of CeO 2 NPs in earthworms; such interactions need to be considered when estimating NP fate and effects in the environment.

A novel biochar from Manihot esculenta Crantz waste: application for the removal of Malachite Green from wastewater and optimization of the adsorption process.

PubMed

Beakou, Buscotin Horax; El Hassani, Kaoutar; Houssaini, Mohammed Amine; Belbahloul, Mounir; Oukani, Elhassan; Anouar, Abdellah

2017-09-01

The adsorptive removal of Malachite Green (MG) by a novel biochar namely Cassava Rind Carbon (CRC) was studied in a batch system. Moreover, Box-Behnken Response Surface Methodology was used to optimize operating conditions of the adsorption process. Characterization was done by Thermo Gravimetric Analysis (TGA), Attenuated Total Reflectance Fourier Transform Infra-Red Spectroscopy (ATR/FTIR), Brunauer-Emmett-Teller (BET) surface area, Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD) and pH zero charge point (pH ZCP ). The pseudo-second-order model and Langmuir model provided the best fit for kinetic and isotherm, respectively. The maximum capacity of dye adsorbed was 932.98 mg/g at 25 °C. The influence of temperature, the mass of adsorbent and the concentration of dye was studied. The optimal amount of adsorbed MG was 1,363.58 mg/g corresponding to 50 °C, 5 mg of CRC and 150 mg/L of dye. According to the high performance exhibited by CRC in this study, Manihot esculenta Crantz waste can be used as a better and low-cost biomass for wastewater decolourization.

The effects of feedstock pre-treatment and pyrolysis temperature on the production of biochar from the green seaweed Ulva.

PubMed

Roberts, David A; de Nys, Rocky

2016-03-15

Green seaweeds from the genus Ulva are a promising feedstock for the production of biochar for carbon (C) sequestration and soil amelioration. Ulva can be cultivated in waste water from land-based aquaculture and Ulva blooms ("green tides") strand millions of tons of biomass on coastal areas of Europe and China each year. The conversion of Ulva into biochar could recycle C and nutrients from eutrophic water into agricultural production. We produce biochar from Ulva ohnoi, cultivated in waste water from an aquaculture facility, and characterize its suitability for C sequestration and soil amelioration through bio-chemical analyses and plant growth experiments. Two biomass pre-treatments (fresh water rinsing to reduce salt, and pelletisation to increase density) were crossed with four pyrolysis temperatures (300-750 °C). Biomass rinsing decreased the ash and increased the C content of the resulting biochar. However, biochar produced from un-rinsed biomass had a higher proportion of fixed C and a higher yield. C sequestration decreased with increasing pyrolysis temperatures due to the combination of lower yield and lower total C content of biochar produced at high temperatures. Biochar produced from un-rinsed biomass at 300 °C had the greatest gravimetric C sequestration (110-120 g stable C kg(-1) seaweed). Biochar produced from un-pelletised Ulva enhanced plant growth three-fold in low fertility soils when the temperature of pyrolysis was less than 450 °C. The reduced effectiveness of the high-temperature biochars (>450 °C) was due to a lower N and higher salt content. Soil ameliorated with biochar produced from pelletised biomass had suppressed plant germination and growth. The most effective biochar for C sequestration and soil amelioration was produced from un-rinsed and un-pelletised Ulva at 300 °C. The green tide that occurs annually along the Shandong coastline in China generates sufficient biomass (200,000 tons dry weight) to ameliorate 12,500 ha of soil, sequester 15,000 t C and recycle 5500 t N into agriculture. We provide clear parameters for biochar production to enable the beneficial use of this biomass. Copyright © 2015 Elsevier Ltd. All rights reserved.

Biochar effect on maize yield and soil characteristics in five conservation farming sites in Zambia

USGS Publications Warehouse

Cornelissen, Gerard; Martinsen, Vegard; Shitumbanuma, Victor; Alling, Vanja; Breedveld, Gijs D.; Rutherford, David W.; Sparrevik, Magnus; Hale, Sarah E.; Obia, Alfred; Mulder, Jan

2013-01-01

Biochar addition to agricultural soils can improve soil fertility, with the added bonus of climate change mitigation through carbon sequestration. Conservation farming (CF) is precision farming, often combining minimum tillage, crop rotation and residue retention. In the present farmer-led field trials carried out in Zambia, the use of a low dosage biochar combined with CF minimum tillage was tested as a way to increase crop yields. Using CF minimum tillage allows the biochar to be applied to the area where most of the plant roots are present and mirrors the fertilizer application in CF practices. The CF practice used comprised manually hoe-dug planting 10-L sized basins, where 10%–12% of the land was tilled. Pilot trials were performed with maize cob biochar and wood biochar on five soils with variable physical/chemical characteristics. At a dosage as low as 4 tons/ha, both biochars had a strong positive effect on maize yields in the coarse white aeolian sand of Kaoma, West-Zambia, with yields of 444% ± 114% (p = 0.06) and 352% ± 139% (p = 0.1) of the fertilized reference plots for maize and wood biochar, respectively. Thus for sandy acidic soils, CF and biochar amendment can be a promising combination for increasing harvest yield. Moderate but non-significant effects on yields were observed for maize and wood biochar in a red sandy clay loam ultisol east of Lusaka, central Zambia (University of Zambia, UNZA, site) with growth of 142% ± 42% (p > 0.2) and 131% ± 62% (p > 0.2) of fertilized reference plots, respectively. For three other soils (acidic and neutral clay loams and silty clay with variable cation exchange capacity, CEC), no significant effects on maize yields were observed (p > 0.2). In laboratory trials, 5% of the two biochars were added to the soil samples in order to study the effect of the biochar on physical and chemical soil characteristics. The large increase in crop yield in Kaoma soil was tentatively explained by a combination of an increased base saturation (from <50% to 60%–100%) and cation exchange capacity (CEC; from 2–3 to 5–9 cmol/kg) and increased plant-available water (from 17% to 21%) as well as water vapor uptake (70 mg/g on maize cob biochar at 50% relative humidity).

Evaluation of nitrate and phosphate adsorption on Al-modified biochar: Influence of Al content.

PubMed

Yin, Qianqian; Ren, Huaipu; Wang, Ruikun; Zhao, Zhenghui

2018-08-01

Biochars with different Al contents (i.e., 5, 10, 15, and 20 wt%) were prepared to evaluate their adsorption capacities for nitrate (NO 3 - ) and phosphate (PO 4 3- ) from eutrophic water. Several techniques, including N 2 adsorption-desorption, X-ray diffraction, scanning electron microscopy, and Fourier transform infrared spectrometry, were applied to characterize the physical-chemical properties of the biochars. We found that the NO 3 - and PO 4 3- adsorptions significantly improved on the Al-modified biochars because of their multifunctional and surface charge properties. In single-solute adsorption, 15 Al/BC and 20 Al/BC exhibited optimal NO 3 - and PO 4 3- adsorption capacities, respectively. In bi-solute coadsorption, the PO 4 3- adsorption on the biochar was less affected with the coexistence of NO 3 - , whereas the coexistence of PO 4 3- had a significant impact on the NO 3 - adsorption. The optimal solution pH for NO 3 - adsorption was 6, and pH < 6 was advantageous to PO 4 3- adsorption. In the kinetic study, the pseudo-second-order model could describe the NO 3 - and PO 4 3- adsorptions on biochar well, indicating that chemical adsorption was the main adsorption mechanism. The Langmuir-Freundlich model agreed well with the NO 3 - and PO 4 3- adsorptions on the biochars, and the maximum adsorption capacities for NO 3 - and PO 4 3- reached 89.58 mg/g and 57.49 mg/g, respectively. Therefore, the Al-modified biochar was a good choice for the remediation of eutrophic water. Copyright © 2018 Elsevier B.V. All rights reserved.

Biochar and enhanced phosphate capture: Mapping mechanisms to functional properties.

PubMed

Shepherd, Jessica G; Joseph, Stephen; Sohi, Saran P; Heal, Kate V

2017-07-01

A multi-technique analysis was performed on a range of biochar materials derived from secondary organic resources and aimed at sustainable recovery and re-use of wastewater phosphorus (P). Our purpose was to identify mechanisms of P capture in biochar and thereby inform its future optimisation as a sustainable P fertiliser. The biochar feedstock comprised pellets of anaerobically digested sewage sludge (PAD) or pellets of the same blended in the ratio 9:1 with ochre sourced from minewater treatment (POCAD), components which have limited alternative economic value. In the present study the feedstocks were pyrolysed at two highest treatment temperatures of 450 and 550 °C. Each of the resulting biochars were repeatedly exposed to a 20 mg l -1 PO 4 -P solution, to produce a parallel set of P-exposed biochars. Biochar exterior and/or interior surfaces were quantitatively characterised using laser-ablation (LA)-ICP-MS, X-ray diffraction, X-ray photo-electron spectroscopy (XPS) and scanning electron microscopy coupled with energy dispersive X-ray. The results highlighted the general importance of Fe minerals in P capture. XPS analysis of POCAD550 indicated lower oxidation state Fe2p3 bonding compared to POCAD450, and LA-ICP-MS indicated stronger covariation of Fe and S, even after P exposure. This suggests that low-solubility Fe/S compounds are formed during pyrolysis, are affected by process parameters and impact on P capture. Other data suggested capture roles for aluminium, calcium and silicon. Overall, our analyses suggest that a range of mechanisms for P capture are concurrently active in biochar. We highlighted the potential to manipulate these through choice of form and composition of feedstock as well as pyrolysis processing, so that biochar may be increasingly tailored towards specific functionality. Copyright © 2017 Elsevier Ltd. All rights reserved.

High adsorption performance for As(III) and As(V) onto novel aluminum-enriched biochar derived from abandoned Tetra Paks.

PubMed

Ding, Zhuhong; Xu, Xuebin; Phan, Thihongnhung; Hu, Xin; Nie, Guangze

2018-06-12

In order to develop promising sorbents for value-added application of solid wastes, low-cost aluminum-enriched biochar was prepared from abandoned Tetra Pak used to hold milks, a paper-polyethylence-Al foil laminated package box, after acid pretreatment and subsequent slow pyrolysis under an oxygen-limited environment at 600 °C. The basic physicochemical properties of the resultant biochar were characterized and the sorption performance of aqueous As(III) and As(V) was investigated via batch and column sorption experiments. Carbon (49.1%), Ca (7.41%) and Al (13.5%) were the most abundant elements in the resultant biochar; and the specific surface area and the pH value at the point of zero charge (pHPZC) were 174 m 2  g -1 and 9.3, respectively. Batch sorption showed excellent sorption performance for both As(III) (24.2 mg g -1 ) and As(V) (33.2 mg g -1 ) and experimental data were fitted well with Langmuir model for the sorption isotherms and pseudo-second order kinetic model for the sorption kinetics. The residual concentrations of As(V) after sorption were below the limited value of arsenic in WHO Guidelines for Drinking water Quality (0.01 mg L -1 ) even if coexistence of PO 4 3- . Column sorption confirmed the high sorption performance for As(III) and As(V). So the slow pyrolysis of abandoned Tetra Paks as low-cost and value-added sorbents is a sustainable strategy for solid waste disposal and wastewater treatment. Copyright © 2018 Elsevier Ltd. All rights reserved.

The challenges of anaerobic digestion and the role of biochar in optimizing anaerobic digestion.

PubMed

Fagbohungbe, Michael O; Herbert, Ben M J; Hurst, Lois; Ibeto, Cynthia N; Li, Hong; Usmani, Shams Q; Semple, Kirk T

2017-03-01

Biochar, like most other adsorbents, is a carbonaceous material, which is formed from the combustion of plant materials, in low-zero oxygen conditions and results in a material, which has the capacity to sorb chemicals onto its surfaces. Currently, research is being carried out to investigate the relevance of biochar in improving the soil ecosystem, digestate quality and most recently the anaerobic digestion process. Anaerobic digestion (AD) of organic substrates provides both a sustainable source of energy and a digestate with the potential to enhance plant growth and soil health. In order to ensure that these benefits are realised, the anaerobic digestion system must be optimized for process stability and high nutrient retention capacity in the digestate produced. Substrate-induced inhibition is a major issue, which can disrupt the stable functioning of the AD system reducing microbial breakdown of the organic waste and formation of methane, which in turn reduces energy output. Likewise, the spreading of digestate on land can often result in nutrient loss, surface runoff and leaching. This review will examine substrate inhibition and their impact on anaerobic digestion, nutrient leaching and their environmental implications, the properties and functionality of biochar material in counteracting these challenges. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effects of biochar and elevated soil temperature on soil microbial activity and abundance in an agricultural system

NASA Astrophysics Data System (ADS)

Bamminger, Chris; Poll, Christian; Marhan, Sven

2014-05-01

As a consequence of Global Warming, rising surface temperatures will likely cause increased soil temperatures. Soil warming has already been shown to, at least temporarily, increase microbial activity and, therefore, the emissions of greenhouse gases like CO2 and N2O. This underlines the need for methods to stabilize soil organic matter and to prevent further boost of the greenhouse gas effect. Plant-derived biochar as a soil amendment could be a valuable tool to capture CO2 from the atmosphere and sequestrate it in soil on the long-term. During the process of pyrolysis, plant biomass is heated in an oxygen-low atmosphere producing the highly stable solid matter biochar. Biochar is generally stable against microbial degradation due to its chemical structure and it, therefore, persists in soil for long periods. Previous experiments indicated that biochar improves or changes several physical or chemical soil traits such as water holding capacity, cation exchange capacity or soil structure, but also biotic properties like microbial activity/abundance, greenhouse gas emissions and plant growth. Changes in the soil microbial abundance and community composition alter their metabolism, but likely also affect plant productivity. The interaction of biochar addition and soil temperature increase on soil microbial properties and plant growth was yet not investigated on the field scale. To investigate whether warming could change biochar effects in soil, we conducted a field experiment attached to a soil warming experiment on an agricultural experimental site near the University of Hohenheim, already running since July 2008. The biochar field experiment was set up as two-factorial randomized block design (n=4) with the factors biochar amendment (0, 30 t ha-1) and soil temperature (ambient, elevated=ambient +2.5° C) starting from August 2013. Each plot has a dimension of 1x1m and is equipped with combined soil temperature and moisture sensors. Slow pyrolysis biochar from the C4 plant Miscanthus was first put on top and then manually incorporated into 20-30 cm soil depth. Differences in the isotopic signature of the biochar and the soil organic matter make it possible to trace the flow of biochar-derived carbon into different labile C pools such as CO2 or microbial biomass. Spring barley litter of the previous growing season was mixed into soil together with the biochar. Rapeseed oil plants were sown one week after biochar application. Weekly gas sampling between the crop rows allows the determination of CO2, N2O and CH4 fluxes. In addition, 13CO2 will be measured at specific dates in order to calculate the proportion of biochar-C in emitted CO2. First soil sampling after biochar application was in November 2013 and soil was taken in three depths (0-5, 5-15 and 15-30 cm). After the first three months we could not observe any effect of biochar on CO2 and N2O emissions, but elevated soil temperature increased emissions of both gases. Data on soil microbial abundance and community composition will be available soon.

Immobilization of metals in contaminated soil from E-waste recycling site by dairy-manure-derived biochar.

PubMed

Chen, Zhiliang; Zhang, Jianqiang; Liu, Minchao; Wu, Yingxin; Yuan, Zhihui

2017-08-24

E-waste is a growing concern around the world and varieties of abandoned E-waste recycling sites, especially in urban area, need to remediate immediately. The impacts of dairy-manure-derived biochars (BCs) on the amelioration of soil properties, the changes in the morphologies as well as the mobility of metals were studied to test their efficacy in immobilization of metals for a potential restoration of vegetation landscape in abandoned E-waste recycling site. The amendment with BCs produced positive effects on bioavailability and mobility reduction for Pb, Cd, Zn and Cu depending on BC ratio and incubation time. The BCs promoted the transformation of species of heavy metals to a more stable fraction, and the metals concentrations in Toxicity Characteristic Leaching Procedure extract declined significantly, especially Pb and Cu. Besides, the BCs ameliorated the substrate with increasing the soil pH, cations exchangeable capacity and available phosphorous, which suggested BC as a potential amendment material for abandoned E-waste recycling sites before restoration of vegetation landscape. Generally, the BC modified by alkaline treatment has a higher efficacy, probably due to increase of specific surface area and porosity as well as the functional groups after alkaline treatment.

Biochar helps enhance maize productivity and reduce greenhouse gas emissions under balanced fertilization in a rainfed low fertility inceptisol.

PubMed

Zhang, Dengxiao; Pan, Genxing; Wu, Gang; Kibue, Grace Wanjiru; Li, Lianqing; Zhang, Xuhui; Zheng, Jinwei; Zheng, Jufeng; Cheng, Kun; Joseph, Stephen; Liu, Xiaoyu

2016-01-01

Maize production plays an important role in global food security, especially in arid and poor-soil regions. Its production is also increasing in China in terms of both planting area and yield. However, maize productivity in rainfed croplands is constrained by low soil fertility and moisture insufficiency. To increase the maize yield, local farmers use NPK fertilizer. However, the fertilization regime (CF) they practice is unbalanced with too much nitrogen in proportion to both phosphorus and potassium, which has led to low fertilizer use efficiency and excessive greenhouse gases emissions. A two-year field experiment was conducted to assess whether a high yielding but low greenhouse gases emission system could be developed by the combination of balanced fertilization (BF) and biochar amendment in a rainfed farmland located in the Northern region of China. Biochar was applied at rates of 0, 20, and 40 t/ha. Results show that BF and biochar increased maize yield and partial nutrient productivity and decreased nitrous oxide (N2O) emission. Under BF the maize yield was 23.7% greater than under CF. N2O emissions under BF were less than half that under CF due to a reduced N fertilizer application rate. Biochar amendment decreased N2O by more than 31% under CF, while it had no effect on N2O emissions under BF. Thus BF was effective at maintaining a high maize yield and reducing greenhouse gases emissions. If combined with biochar amendment, BF would be a good way of sustaining low carbon agriculture in rainfed areas. Copyright © 2015 Elsevier Ltd. All rights reserved.

Thermal properties of soils: effect of biochar application

NASA Astrophysics Data System (ADS)

Usowicz, Boguslaw; Lukowski, Mateusz; Lipiec, Jerzy

2014-05-01

Thermal properties (thermal conductivity, heat capacity and thermal diffusivity) have a significant effect on the soil surface energy partitioning and resulting in the temperature distribution. Thermal properties of soil depend on water content, bulk density and organic matter content. An important source of organic matter is biochar. Biochar as a material is defined as: "charcoal for application as a soil conditioner". Biochar is generally associated with co-produced end products of pyrolysis. Many different materials are used as biomass feedstock for biochar, including wood, crop residues and manures. Additional predictions were done for terra preta soil (also known as "Amazonian dark earth"), high in charcoal content, due to adding a mixture of charcoal, bone, and manure for thousands of years i.e. approximately 10-1,000 times longer than residence times of most soil organic matter. The effect of biochar obtained from the wood biomass and other organic amendments (peat, compost) on soil thermal properties is presented in this paper. The results were compared with wetland soils of different organic matter content. The measurements of the thermal properties at various water contents were performed after incubation, under laboratory conditions using KD2Pro, Decagon Devices. The measured data were compared with predictions made using Usowicz statistical-physical model (Usowicz et al., 2006) for biochar, mineral soil and soil with addition of biochar at various water contents and bulk densities. The model operates statistically by probability of occurrence of contacts between particular fractional compounds. It combines physical properties, specific to particular compounds, into one apparent conductance specific to the mixture. The results revealed that addition of the biochar and other organic amendments into the soil caused considerable reduction of the thermal conductivity and diffusivity. The mineral soil showed the highest thermal conductivity and diffusivity that decreased in soil with addition of biochar and pure biochar. The reduction of both properties was mostly due to decrease in both particle density and bulk density. Both biochar and the organic amendments addition resulted in a decrease of the heat capacity of the mixtures in dry state and considerable increase in wet state. The lowest and highest reduction in the thermal conductivity with decreasing water content was obtained for pure biochar and mineral soil, respectively. The thermal diffusivity had a characteristic maximum at higher bulk densities and lower water contents. The wetland soil higher in organic matter content exhibit smaller temporal variation of the thermal properties compared to soils lower in organic matter content in response to changes of water content. The statistical-physical model was found to be useful for satisfactory predicting thermal properties of the soil with addition of biochar and organic amendments. Usowicz B. et al., 2006. Thermal conductivity modelling of terrestrial soil media - A comparative study. Planetary and Space Science 54, 1086-1095.

Chemical recalcitrance of biochar and wildfire charcoal: how similar are they?

NASA Astrophysics Data System (ADS)

Santin, Cristina; Doerr, Stefan H.; Merino, Agustin

2016-04-01

The enhanced chemical resistance to biological degradation of pyrogenic materials, either produced during wildfires (charcoal) or by man (biochar), makes them long-term carbon sinks once incorporated in soils. In spite of their fundamental similarities, studies comparing the chemical recalcitrance of biochar and wildfire charcoal are scarce because analogous materials for accurate comparison are not easily available. Using solid-state 13C cross polarization-magic angle spinning nuclear magnetic resonance spectroscopy we characterized the chemical recalcitrance of pyrogenic materials generated from the same unburnt feedstooks (litter and dead wood from Pinus banksiana): (a) charcoal from a high-intensity wildfire and (b) biochar obtained by slow pyrolysis [3 treatments: 2 h at 350, 500 and 650°C]. For quantification, the spectra were divided into four regions representing different chemical environments of the 13C nucleus: alkyl C (0-45 ppm), O-alkyl C (45-110 ppm), olefinic and aromatic C(110-160 ppm), and carbonyl C (160-210 ppm). As an indicator of chemical recalcitrance, the degree of aromaticity (%) was calculated as follow: aromatic-C ∗ 100 / (alkyl C+ O alkyl-C + aromatic-C). The pyrogenic materials derived from wood show higher degrees of aromaticity (68 to 88%) than pyrogenic material derived from litter (40 to 88%). When comparing biochar and wildfire charcoal, biochars produced at 500 and 650°C always have higher degrees of aromaticity than wildfire charcoals, irrespective of the original feedstock. Wildfire charcoals always show a more heterogeneous chemical composition, with alkyl and O-alkyl compounds present even in charcoal generated at very high temperatures (temperatures up to 950 °C were recorded on the litter surface during the wildfire). However, biochars produced at 500 and 650 °C are mostly aromatic, and only the biochars produced at 350 °C show partial contribution of alkyl-C compounds. Our results suggest that biochar-type pyrogenic materials have in general a higher chemical recalcitrance than wildfire charcoal and, thus, we advice caution when transfer knowledge between the biochar and the wildfire charcoal research communities.

Biochar assisted thermophilic co-digestion of food waste and waste activated sludge under high feedstock to seed sludge ratio in batch experiment.

PubMed

Li, Qian; Xu, Manjuan; Wang, Gaojun; Chen, Rong; Qiao, Wei; Wang, Xiaochang

2018-02-01

Batch experiments were conducted using biochar (BC) to promote stable and efficient methane production from thermophilic co-digestion of food waste (FW) and waste activated sludge (WAS) at feedstock/seed sludge (F/S) ratios of 0.25, 0.75, 1.5, 2.25, and 3. The results showed that the presence of BC dramatically shortened the lag time of methane production and increased the methane production rate with increased organic loading. The higher buffer capacity and large specific surface area of BC promoted microorganism growth and adaption to VFAs accumulation. Additionally, the electron exchange in syntrophic oxidation of butyrate and acetate as intermediate products was significantly facilitated by BC possibly due to the selective succession of bacteria and methanogens which may have participated in direct interspecies electron transfer, in contrast with the control group with low-efficient electron ferried between syntrophic oxidizers and methanogens using hydrogen as the electron carrier. Copyright © 2017 Elsevier Ltd. All rights reserved.

Biochar supported nanoscale zerovalent iron composite used as persulfate activator for removing trichloroethylene.

PubMed

Yan, Jingchun; Han, Lu; Gao, Weiguo; Xue, Song; Chen, Mengfang

2015-01-01

Biochar (BC) supported nanoscale zerovalent iron (nZVI) composite was synthesized and used as an activator for persulfate to enhance the trichloroethylene (TCE) removal in aqueous solutions. The degradation efficiency of TCE (0.15mmolL(-1)) was 99.4% in the presence of nZVI/BC (4.5mmolL(-1), nZVI to BC mass ratio was 1:5) and persulfate (4.5mmolL(-1)) within 5min, which was significantly higher than that (56.6%) in nZVI-persulfate system under the same conditions. Owing to large specific surface area and oxygen-containing functional groups of BC, nZVI/BC enhanced the SO4(-) generation and accelerated TCE degradation. On the basis of the characterization and analysis data, possible activation mechanisms of the Fe(2+)/Fe(3+) (Fe(II)/Fe(III)) redox action and the electron-transfer mediator of the BC oxygen functional groups promoting the generation of SO4(-) in nZVI/BC-persulfate system were clarified. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of steam activation of biochar produced from a giant Miscanthus on copper sorption and toxicity.

PubMed

Shim, Taeyong; Yoo, Jisu; Ryu, Changkook; Park, Yong-Kwon; Jung, Jinho

2015-12-01

This study aims to evaluate the physiochemical properties, sorption characteristics, and toxicity effects of biochar (BC) produced from Miscanthus sacchariflorus via slow pyrolysis at 500°C and its steam activation product (ABC). Although BC has a much lower surface area than ABC (181 and 322m(2)g(-1), respectively), the Cu sorption capacities of BC and ABC are not significantly different (p>0.05). A two-compartment model successfully explains the sorption of BC and ABC as being dominated by fast and slow sorption processes, respectively. In addition, both BC and ABC efficiently eliminate the toxicity of Cu towards Daphnia magna. However, ABC itself induced acute toxicity to D. magna, which is possibly due to increased aromaticity upon steam activation. These findings suggest that activation of BC produced from M. sacchariflorus at a pyrolytic temperature of 500°C may not be appropriate in terms of Cu sorption and toxicity reduction. Copyright © 2015 Elsevier Ltd. All rights reserved.

Mechanistic understanding of crystal violet dye sorption by woody biochar: implications for wastewater treatment.

PubMed

Wathukarage, Awanthi; Herath, Indika; Iqbal, M C M; Vithanage, Meththika

2017-08-17

Dye-based industries, particularly small and medium scale, discharge their effluents into waterways without treatment due to cost considerations. We investigated the use of biochars produced from the woody tree Gliricidia sepium at 300 °C (GBC300) and 500 °C (GBC500) in the laboratory and at 700 °C from a dendro bioenergy industry (GBC700), to evaluate their potential for sorption of crystal violet (CV) dye. Experiments were conducted to assess the effect of pH reaction time and CV loading on the adsorption process. The equilibrium adsorption capacity was higher with GBC700 (7.9 mg g -1 ) than GBC500 (4.9 mg g -1 ) and GBC300 (4.4 mg g -1 ), at pH 8. The CV sorption process was dependent on the pH, surface area and pore volume of biochar (GBC). Both Freundlich and Hill isotherm models fitted best to the equilibrium isotherm data suggesting cooperative interactions via physisorption and chemisorption mechanisms for CV sorption. The highest Hill sorption capacity of 125.5 mg g -1 was given by GBC700 at pH 8. Kinetic data followed the pseudo-second-order model, suggesting that the sorption process is more inclined toward the chemisorption mechanism. Pore diffusion, π-π electron donor-acceptor interaction and H-bonding were postulated to be involved in physisorption, whereas electrostatic interactions of protonated amine group of CV and negatively charged GBC surface led to a chemisorption type of adsorption. Overall, GBC produced as a by-product of the dendro industry could be a promising remedy for CV removal from an aqueous environment.

Sorption of the monoterpenes α-pinene and limonene to carbonaceous geosorbents including biochar.

PubMed

Hale, Sarah E; Endo, Satoshi; Arp, Hans Peter H; Zimmerman, Andrew R; Cornelissen, Gerard

2015-01-01

The sorption of two monoterpenes, α pinene and limonene to the carbonaceous geosorbents graphite, bituminous coal, lignite coke, biochar and Pahokee peat was quantified. Polyethylene (PE) passive samplers were calibrated for the first time for these compounds by determining the PE-water partitioning coefficients and used as a tool to determine sorption to the carbonaceous geosorbents. Log KPE-water values were 3.49±0.58 for α pinene and 4.08±0.27 for limonene. The sorption of limonene to all materials was stronger than that for α pinene (differences of 0.2-1.3 log units between distribution coefficients for the monoterpenes). Placing Kd values in increasing order for α pinene gave biochar≈Pahokee peat≈bituminous coal≈lignite coke

Biochar and lignite affect H+-ATPase and H+-PPase activities in root tonoplast and nutrient contents of mung bean under salt stress.

PubMed

Torabian, Shahram; Farhangi-Abriz, Salar; Rathjen, Judith

2018-05-31

This research was conducted to evaluate effects of biochar (50 and 100 g kg -1 soil) and lignite (50 and 100 g kg -1 soil) treatments on H + -ATPase and H + -PPase activity of root tonoplast, nutrient content, and performance of mung bean under salt stress. High saline conditions increased H + -ATPase and H + -PPase activities in root tonoplast, sodium (Na) content, reactive oxygen species (H 2 O 2 and O 2 - ) generation, relative electrolyte leakage (REL) and 2,2-Diphenyl-1-picrylhydrazyl (DPPH) activity in root and leaf, but decreased relative water content (RWC), chlorophyll content index, leaf area, potassium (K), calcium (Ca), magnesium (Mg), zinc (Zn) and iron (Fe) content of plant tissues, root and shoot dry weight of mung bean. Lignite and biochar treatments decreased the H + -ATPase and H + -PPase activities of root tonoplast under salt stress. Moreover, these treatments increased the cation exchange capacity of soil and nutrient values in plant tissues. Biochar and lignite diminished the generation of reactive oxygen species and DPPH activity in root and leaf cells, and these superior effects improved chlorophyll content index, leaf area and growth of mung bean under both conditions. In general, the results of this study demonstrated that biochar and lignite decreased the entry of Na ion into the cells, enriched plant cells with nutrients, and consequently improved mung bean performance under salt toxicity. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Biochars made from agro-industrial by-products remove chlorine and lower water toxicity

NASA Astrophysics Data System (ADS)

Tzachristas, Andreas; Xirou, Maria; Manariotis, Ioannis D.; Dailianis, Stefanos; Karapanagioti, Hrissi K.

2016-04-01

Chlorination is the most common disinfection process for water and treated wastewater. For the industrial use of water in food production, chlorine can add undesired taste and odor to the final product. For this reason, dechlorination is desired for food industries that use municipal tap water. For treated wastewater discharge or reuse, chlorine can be toxic to the receiving aqueous systems and to the irrigated plants. In both the above cases, dechlorination is also required. Traditionally activated carbon has been used as the ideal material for the removal of chlorine. The main mechanisms that describe the interaction between activated carbon and HOCl or OCl- are described by the following equations (AWWA, 1990): HOCl + C* → C*O + H+ + Cl- (1), OCl- + C* → C*O + Cl- (2) Where C* and C*O represent the activated carbon surface and a surface oxide, respectively. The present study proposes the use of agro-industrial by-products for the production of biochars that will be used for dechlorination of tap-water used for food-industry production. Different raw materials such as malt spent rootlets, coffee residue, olive and grape seeds, etc. are used for the production of biochar. Various temperatures and air-to-solid ratios are tested for optimizing biochar production. Batch tests as well as a column test are employed to study the dechlorination efficiency and kinetics of the different raw and biochar materials as well as those of commercial activated carbons. As chlorine concentration increases the removal also increases linearily. After 1 and 24 hours of contact the chlorine relative removal efficiencies for the biochar made from olive seeds are 50 and 77 ± 4%, respectively. It seems that the removal kinetics are faster during the first hour; then, removal continues but with a slower rate. Most of the biochars tested (with 3 mg of solid in 20 mL of chlorine solution at initial concentration Co=1.5 mg/L) demonstrated removal efficiencies with an average of 9.4 ± 0.5 mg/g. For the two commercial activated carbons, removal efficiencies were 11.4 ± 0.2 mg/g. The column experiment also showed positive results; no breakthrough has been observed after 1L of chlorine solution has passed through a column packed with 4 g of biochar made from the pyrolysis of grape seeds. Toxicity tests were also performed with the chlorine solution before and after passing through this column. The toxicity of the solution decreased after passing through the column packed with biochar suggesting that no toxic compounds are formed during the removal of chlorine by the biochar. The overall idea of this study is the sustainable use of the solid by-products of a food industry or producer to treat water or treated wastewater in order to enhance its quality and lower its toxicity. American Water Works Association (AWWA) 1990 Water quality and treatment, a handbook of community water supplies, Fourth edition.

Biochar increases nitrogen retention and lowers greenhouse gas emissions when added to composting poultry litter.

PubMed

Agyarko-Mintah, Eunice; Cowie, Annette; Singh, Bhupinder Pal; Joseph, Stephen; Van Zwieten, Lukas; Cowie, Alan; Harden, Steven; Smillie, Robert

2017-03-01

Biochar has intrinsic and nascent structural and sorption properties that may alter the physical and chemical properties of a composting mixture thus influencing the production of greenhouse gases [GHGs; nitrous oxide (N 2 O) and methane (CH 4 )]. In this study, contrasting biochars produced from greenwaste (GWB) or poultry litter (PLB) were incorporated into a composting mixture containing poultry litter and straw, and GHG emissions were measured in situ during composting using Fourier Transform Infrared Spectroscopy (FTIR). Emissions of N 2 O from the biochar-amended composting mixtures decreased significantly (P<0.05) soon after commencement of the composting process compared with the non-amended control. The cumulative emissions of N 2 O over 8weeks in the GWB composting mixture (GWBC), PLB composting mixture (PLBC) and control (no biochar) were 4.2, 5.0 and 14.0gN 2 O-Nkg -1 of total nitrogen (TN) in composting mixture, respectively (P<0.05). The CH 4 emissions were significantly (P<0.05) lower in the GWBC and PLBC treatments than the control during the period from day 8 to day 36, when anaerobic conditions likely prevailed. The cumulative CH 4 emissions were 12, 18 and 80mg CH 4 -Ckg -1 of total carbon (TC) for the GWBC, PLBC and control treatments, respectively, though due to wide variation between replicates this difference was not statistically significant. The cumulative N 2 O and CH 4 emissions were similar between the GWBC and PLBC despite differences in properties of the two biochars. X-ray Photoelectron Spectroscopy (XPS) analysis and SEM imaging of the composted biochars indicated the presence of iron oxide compounds and amine-NH 3 on the surface and pores of the biochars (PLB>GWB). The change in nitrogen (N) functional groups on the biochar surface after composting is evidence for sorption and/or reaction with N from labile organic N, mineral N, and gaseous N (e.g. N 2 O). The concentration of NH 4 + increased during the thermophilic phase and then decreased during the maturation phase, while NO 3 - accumulated during the maturation phase. Total N retained was significantly (P<0.05) higher in the PLBC (740g) and the GWBC (660g) relative to the control (530g). The TC retained was significantly higher in the GWBC (10.0kg) and the PLBC (8.5kg) cf. the control (6.0kg). Total GHG emissions across the composting period were 50, 63 and 183kg CO 2 -eqt -1 of initial mass of GWBC, PLBC and control (dry weight basis) respectively. These results support the co-composting of biochar to lower net emissions of GHGs while increasing N retention (and fertiliser N value) in the mature compost. Copyright © 2016. Published by Elsevier Ltd.

Competitive adsorption of Pb(II), Cu(II), and Zn(II) ions onto hydroxyapatite-biochar nanocomposite in aqueous solutions

NASA Astrophysics Data System (ADS)

Wang, Yu-Ying; Liu, Yu-Xue; Lu, Hao-Hao; Yang, Rui-Qin; Yang, Sheng-Mao

2018-05-01

A hydroxyapatite-biochar nanocomposite (HAP-BC) was successfully fabricated and its physicochemical properties characterized. The analyses showed that HAP nanoparticles were successfully loaded on the biochar surface. The adsorption of Pb(II), Cu(II), and Zn(II) by HAP-BC was systematically studied in single and ternary metal systems. The results demonstrated that pH affects the adsorption of heavy metals onto HAP-BC. Regarding the adsorption kinetics, the pseudo-second-order model showed the best fit for all three heavy metal ions on HAP-BC. In both single and ternary metal ion systems, the adsorption isotherm of Pb(II) by HAP-BC followed Langmuir model, while those of Cu(II) and Zn(II) fitted well with Freundlich model. The maximum adsorption capacity for each tested metal by HAP-BC was higher than that of pristine rice straw biochar (especially for Pb(II)) or those of other reported adsorbents. Therefore, HAP-BC could explore as a new material for future application in heavy metal removal.

Pb(II) sorption from aqueous solution by novel biochar loaded with nano-particles.

PubMed

Wang, Chongqing; Wang, Hui

2018-02-01

Novel sorbent (HBC) is prepared by introducing nano-particles (Maghemite and EDTA functionalized layered double hydroxides) on biochar surface. FTIR, XRD, SEM and EDS are used to characterize the biochar nanocomposites. Pb(II) sorption is highly dependent on solution pH. Sorption kinetics and isotherms indicate that Pb(II) sorption onto the sorbents follows pseudo-second order model and Langmuir isotherm. The maximum sorption capacity of Pb(II) onto HBC is up to146.84 mg g -1 , higher than previously reported sorbents. The magnetic particles enable easy separation of HBC from aqueous solution by external magnetic fields. HBC can be used as effective sorbent for removal of heavy metals from wastewater. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ecotoxicological standard tests confirm beneficial effects of nitrate capture in organically coated grapewood biochar

NASA Astrophysics Data System (ADS)

Haller, Andreas; Kammann, Claudia; Löhnertz, Otmar

2017-04-01

Due to the rising use of mineral N fertilizers and legume use in agriculture, the input of reactive N into the global N cycle has dramatically increased. Therefore new agricultural techniques that increase N use efficiency and reduce the loss of soil mineral N to surface and ground waters are urgently required. Pyrogenic carbon (biochar) produced from biomass may be used as a beneficial soil amendment to sequester carbon (C) in soils, increase soil fertility in the long term, and reduce environmental pollution such as nitrate leaching or N2O emissions. However, reduced nitrate leaching is not a constant finding when using biochar as a soil amendment and the mechanisms are poorly understood. To investigate if biochar is able to reduce nitrate pollution and its subsequent effects on soil and aquatic fauna, we conducted a series of experiments using standard ecotoxicological test methods: (1) the collembolan reproduction test (ISO 11267 (1999)), (2) the earthworm reproduction test (ISO 11268-2 (1998)), (3) the aquatic Daphnia acute test (ISO 6341 (1996)) and (4) a seedling emergence and growth test (ISO 11269-2 (2006)) also involving leaching events. For the tests grapewood biochar produced with a Kon-Tiki kiln (600-700°C) was used which had previously demonstrated nitrate capture; terrestrial tests were carried out with loamy sand standard soil 2.2 (LUFA-Speyer, Germany). The tests included the factors: (A) nitrate addition (using critical values for the test organisms) or no nitrate addition, (B) control (no biochar), pure biochar and organically-coated biochar. In the aquatic test (3), a nitrate amount which caused 50% of the Daphnia-immobilizing toxic nitrate concentration in leachates was applied to the soil or soil-biochar mixtures. Subsequently, soils were incubated overnight and leached on the next day, producing (in the control) the calculated nitrate concentrations. Daphnids were incubated for 48 hours. Test results without nitrate confirmed that soil-biochar leachates did not impact Daphnia mobility. However, in the nitrate-amended control, Daphnia mobility was reduced by 52% as expected, while mobility was only reduced by 28% (pure BC) and by 16% (coated BC), respectively; this coincided with reduced nitrate concentrations in the leachates. In the presence of both biochars without high nitrate levels, adult earthworm biomass (2) was not different from that of the control, while the reproductive success (number of juvenile) increased by +46% with the coated biochar. With high nitrate concentrations, the reproductive success was strongly reduced by 96.7% (adult earthworm biomass remained constant). With the pure and coated biochars, the reproductive success increased by +171% and +678% compared to the (strongly reduced) soil-only control, respectively. The same response patterns were found in the collembolan test (1). In all cases biochar effects were correlated to nitrate capture in biochar particles which was more pronounced in the organically coated biochar. In conclusion post-treated biochars may be used as a tool for reducing nitrate pollution. However, more research is clearly needed. Acknowledgement: CK and AH gratefully acknowledge financial support of DFG grant KA3442/1-1 and the "OptiChar4EcoVin" project funded by the Hessian Ministry for Higher Education, Research and the Arts.

Soil nitrogen dynamics and Capsicum Annuum sp. plant response to biochar amendment in silt loam soil

NASA Astrophysics Data System (ADS)

Horel, Agota; Gelybo, Gyorgyi; Dencso, Marton; Toth, Eszter; Farkas, Csilla; Kasa, Ilona; Pokovai, Klara

2017-04-01

The present study investigated the growth of Capsicum Annuum sp. (pepper) in small-scale experiment to observe changes in plant growth and health as reflected by leaf area, plant height, yield, root density, and nitrogen usage. Based on field conditions, part of the study aimed to examine the photosynthetic and photochemical responses of plants to treatments resulting from different plant growth rates. During the 12.5 week long study, four treatments were investigated with biochar amount of 0, 0.5%, 2.5%, and 5.0% (by weight) added to silt loam soil. The plants were placed under natural environmental conditions, such that photosynthetic activities from photosynthetically active radiation (PAR) and the plants photochemical reflectance index (PRI) could be continuously measured after exposure to sunlight. In this study we found that benefits from biochar addition to silt loam soil most distinguishable occurred in the BC2.5 treatments, where the highest plant yield, highest root density, and highest leaf areas were observed compared to other treatments. Furthermore, data showed that too low (0.5%) or too high (5.0%) biochar addition to the soil had diminishing effects on Capsicum Annuum sp. growth and yield over time. At the end of the 12th week, BC2.5 had 22.2%, while BC0.5 and BC5.0 showed 17.4% and 15.7% increase in yield dry weight respectively compared to controls. The collected data also showed that the PRI values of plants growing on biochar treated soils were generally lower compared to control treatments, which could relate to leaf nitrogen levels. Total nitrogen amount showed marginal changes over time in all treatments. The total nitrogen concentration showed 28.6% and 17.7% increase after the 6th week of the experiment for BC2.5 and BC5.0, respectively, while inorganic nutrients of NO3-N and NH4+-N showed a continuous decrease during the course of the study, with a substantial drop during the first few weeks. The present study provides evidence for impact of biochar on plant stress levels and growth function in biochar amended soils. Our findings emphasize the necessity for optimization to local parameters prior to biochar additions to soils.

Biochars made from agro-industrial by-products remove chlorine from water and wastewater

NASA Astrophysics Data System (ADS)

Tzachristas, Andreas; Manariotis, Ioannis D.; Karapanagioti, Hrissi K.

2017-04-01

Chlorination is the most common disinfection process for water and wastewater. For the industrial use of water in food production, chlorine can add undesired taste and odor to the final product. For this reason, dechlorination is desired for food industries that use municipal tap water. For treated wastewater discharge or reuse, chlorine can be toxic to the receiving aqueous systems and to the irrigated plants. In both the above cases, dechlorination is also required. Traditionally activated carbon has been used as the ideal material for the removal of chlorine. The main mechanisms that describe the interaction between activated carbon and HOCl or OCl- are described by the following equations (AWWA, 1990): HOCl + C* → C*O + H+ + Cl- (1), OCl- + C* → C*O + Cl- (2) Where C* and C*O represent the activated carbon surface and a surface oxide, respectively. The present study proposes the use of agro-industrial by-products for the production of biochars that will be used for dechlorination of tap-water used for food-industry production. Different raw materials such as malt spent rootlets, coffee residue, olive and grape seeds, etc. are used for the production of biochar. Various temperatures and air-to-solid ratios are tested for optimizing biochar production. Batch tests as well as a column test are employed to study the dechlorination kinetics of the different raw and biochar materials as well as those of commercial activated carbons. The removal kinetics are faster during the first hour; then, removal continues but with a slower rate. Most of the biochars tested (with 3 mg of solid in 20 mL of chlorine solution at initial concentration Co=1.5 mg/L) demonstrated removal efficiencies with an average of 9.4 ± 0.5 mg/g. For the two commercial activated carbons, removal efficiencies were 11.4 ± 0.2 mg/g. The first-order constant k1 ranged between 0.001 and 0.014 (min-1) for the biosorbents and the biochars and it was equal to 0.017 (min-1) for the commercial activated carbons. Consequently, the half-life time ranged between 50 and 700 (min) for the biosorbents and the biochars and it was equal to 41 (min) for the commercial activated carbons. The column experiment also showed positive results; A breakthrough for concentrations higher than 10(AWWA) 1990 Water quality and treatment, a handbook of community water supplies, Fourth edition, American Water Works Association Fourth edition.

Predicting sorption of organic acids to a wide range of carbonized sorbents

NASA Astrophysics Data System (ADS)

Sigmund, Gabriel; Kah, Melanie; Sun, Huichao; Hofmann, Thilo

2016-04-01

Many contaminants and infochemicals are organic acids that undergo dissociation under environmental conditions. The sorption of dissociated anions to biochar and other carbonized sorbents is typically lower than that of neutral species. It is driven by complex processes that are not yet fully understood. It is known that predictive approaches developed for neutral compounds are unlikely to be suitable for organic acids, due to the effects of dissociation on sorption. Previous studies on the sorption of organic acids to soils have demonstrated that log Dow, which describes the decrease in hydrophobicity of acids upon dissociation, is a useful alternative to log Kow. The aim of the present study was to adapt a log Dow based approach to describe the sorption of organic acids to carbonized sorbents. Batch experiments were performed with a series of 9 sorbents (i.e., carbonized wood shavings, pig manure, and sewage sludge, carbon nanotubes and activated carbon), and four acids commonly used for pesticidal and biocidal purposes (i.e., 2,4-D, MCPA, 2,4-DB, and triclosan). Sorbents were comprehensively characterized, including by N2 and CO2 physisorption, Fourier transform infrared spectroscopy, and elemental analysis. The wide range of sorbents considered allows (i) discussing the mechanisms driving the sorption of neutral and anionic species to biochar, and (ii) their dependency on sorbate and sorbent properties. Results showed that the sorption of the four acids was influenced by factors that are usually not considered for neutral compounds (i.e., pH, ionic strength). Dissociation affected the sorption of the four compounds, and sorption of the anions ranged over five orders of magnitude, thus substantially contributing to sorption in some cases. For prediction purposes, most of the variation in sorption to carbonized sorbents (89%) could be well described with a two-parameter regression equation including log Dow and sorbent specific surface area. The proposed model may serve as a base to estimate the environmental fate of organic acids in the presence of carbonized sorbents such as biochar, and help assess (i) the potential application of biochar for remediation purposes and (ii) the potential effect of biochar addition to soil.

Yield-scaled N2O emissions were effectively reduced by biochar amendment of sandy loam soil under maize - wheat rotation in the North China Plain

NASA Astrophysics Data System (ADS)

Niu, Yuhui; Chen, Zengming; Müller, Christoph; Zaman, Monhammad M.; Kim, Donggill; Yu, Hongyan; Ding, Weixin

2017-12-01

It is increasingly recognized that the addition of biochar to soil has potential to mitigate climate change and increase soil fertility by enhancing carbon (C) storage. However, the effect of biochar on yield and nitrous oxide (N2O) emissions from upland fields remains unclear. In this study, a one-year field experiment was conducted in an area of calcareous fluvo-aquic soil to assess and quantify the effect of maize straw biochar in reducing N2O loss during 2014-2015 in the North China Plain. Eight treatments were designed as follows: no nitrogen (N) fertilizer (control, CK); biochar application at rates of 3 (B3), 6 (B6) and 12 (B12) t ha-1; chemical fertilizer (NPK) application at 200 kg N ha-1 (F); and fertilizer plus biochar application at rates of 3 (FB3), 6 (FB6) and 12 (FB12) t ha-1. Crop yield, N2O fluxes, soil mineral N concentrations, and soil auxiliary parameters were measured following the application of treatments during each season. During the maize growing season, N2O emission was 0.57 kg N2O-N ha-1 under CK treatment, and increased to 0.88, 0.93 and 1.10 kg N2O-N ha-1 under B3, B6 and B12, respectively. In contrast, N2O emissions were significantly reduced by 31.4-39.9% (P < 0.05) under FB treatments compared with F, and the N2O emission factor of the applied N was reduced from 1.36% under F to 0.71-0.85% under FB. There was also a significant interaction effect of fertilizer and biochar on N2O emissions (P < 0.01). During the wheat growing season, biochar had no effect on N2O emissions regardless of the fertilizer regime. Biochar application did not affect maize yield; however, a significant increase in wheat yield of 16.6-25.9% (P < 0.05) was observed without N fertilization. Nevertheless, a reduction in wheat yield was measured at a biochar rate of 12 t ha-1 with fertilization. Overall, under maize cropping, N2O emissions per unit yield of grain, biomass, grain N and biomass N (yield-scaled N2O emissions) were significantly reduced by 32.4-39.9% under FB compared with F treatment, regardless of the biochar application rate. Biochar did not affect yield-scaled N2O emissions in wheat. Decreased soil bulk density with biochar is suggested to reduce the denitrification potential and N2O emissions; while increased retention capacity of fertilizer N in biochar-added soil decreased wheat growth and yield. These findings suggest that N fertilization plus biochar application at 3 t ha-1 is a practical strategy for reducing yield-scaled N2O emissions from maize fields in the North China Plain.

Preparation of biochar from sewage sludge

NASA Astrophysics Data System (ADS)

Nieto, Aurora; María Méndez, Ana; Gascó, Gabriel

2013-04-01

Biomass waste materials appropriate for biochar production include crop residues (both field residues and processing residues such as nut shells, fruit pits, bagasse, etc), as well as yard, food and forestry wastes, and animal manures. Biochar can and should be made from biomass waste materials and must not contain unacceptable levels of toxins such as heavy metals which can be found in sewage sludge and industrial or landfill waste. Making biochar from biomass waste materials should create no competition for land with any other land use option—such as food production or leaving the land in its pristine state. Large amounts of agricultural, municipal and forestry biomass are currently burned or left to decompose and release CO2 and methane back into the atmosphere. They also can pollute local ground and surface waters—a large issue for livestock wastes. Using these materials to make biochar not only removes them from a pollution cycle, but biochar can be obtained as a by-product of producing energy from this biomass. Sewage sludge is a by-product from wastewater treatment plants, and contains significant amounts of heavy metals, organic toxins and pathogenic microorganisms, which are considered to be harmful to the environment and all living organisms. Agricultural use, land filling and incineration are commonly used as disposal methods. It was, however, reported that sewage sludge applications in agriculture gives rise to an accumulation of harmful components (heavy metals and organic compounds) in soil. For this reason, pyrolysis can be considered as a promising technique to treat the sewage sludge including the production of fuels. The objective of this work is to study the advantages of the biochar prepared from sewage sludge.

Sensitive voltammetric determination of lead released from ceramic dishes by using of bismuth nanostructures anchored on biochar.

PubMed

Agustini, Deonir; Mangrich, Antonio Salvio; Bergamini, Márcio F; Marcolino-Junior, Luiz Humberto

2015-09-01

A simple and sensitive electroanalytical method was developed for determination of nanomolar levels of Pb(II) based on the voltammetric stripping response at a carbon paste electrode modified with biochar (a special charcoal) and bismuth nanostructures (nBi-BchCPE). The proposed methodology was based on spontaneous interactions between the highly functionalized biochar surface and Pb(II) ions followed by reduction of these ions into bismuth nanodots which promote an improvement on the stripping anodic current. The experimental procedure could be summarized in three steps: including an open circuit pre-concentration, reduction of accumulated lead ions at the electrode surface and stripping step under differential pulse voltammetric conditions (DPAdSV). SEM images revealed dimensions of bismuth nanodots ranging from 20 nm to 70 nm. The effects of main parameters related to biochar, bismuth and operational parameters were examined in detail. Under the optimal conditions, the proposed sensor has exhibited linear range from 5.0 to 1000 nmol L(-1) and detection limit of 1.41 nmol L(-1) for Pb(II). The optimized method was successfully applied for determination of Pb(II) released from overglaze-decorated ceramic dishes. Results obtained were compared with those given by inductively coupled plasma optical emission spectroscopy (ICP-OES) and they are in agreement at 99% of confidence level. Copyright © 2015. Published by Elsevier B.V.

Sorption of ionic and nonionic organic solutes onto giant Miscanthus-derived biochar from methanol-water mixtures.

PubMed

Kim, Juhee; Hyun, Seunghun

2018-02-15

The sorption of naphthalene (NAP) and 1-naphthoic acid (1-NAPA) onto giant Miscanthus-derived biochar was investigated in methanol volume fractions (f c ) of 0-0.6 as a function of ionic composition (5mM CaCl 2 and 10mM KCl) and liquid pH (2 and 7). The sorption onto biochar was nonlinear with 0.42≤N≤0.95; thus, a concentration-specific sorption constant (K m ) was compared. The K m log linearly decreased with increasing f c , except for 1-NAPA from a CaCl 2 mixture at pH7. Isotherm data was fitted with a cosolvency sorption model through which the slope (ασ) of the inverse log linear K m -f c plot and empirical constant (α) were obtained. NAP sorption was well described by the cosolvency model with the α value being 0.41-0.53, indicating a methanol-biochar interaction favoring more sorption than the cosolvency based prediction. In particular, the slope (ασ) of 1-NAPA was lower than that of NAP, indicating less reduction of 1-NAPA sorption (i.e., lower α value) by methanol. In comparison with other sorbents, the α value was approximately intermediate between a humic substance and kaolinite clay. An analysis of FT-IR spectra suggested the transformation of O-containing functional groups by methanol, which will subsequently boost the π-π interaction between an organic solute and biochar. Moreover, Ca 2+ -induced sorption between anionic 1-NAPA and a negatively charged biochar surface was also fortified in the methanol mixture. The results revealed unexplored cosolvent effects on organic solute sorption onto biochar and identified the hydrophobic and hydrophilic sorption moieties of biochar as affected by the cosolvent. Copyright © 2017 Elsevier B.V. All rights reserved.

The biosorption capacity of biochar for 4-bromodiphengl ether: study of its kinetics, mechanism, and use as a carrier for immobilized bacteria.

PubMed

Du, Jingting; Sun, Pengfei; Feng, Zhuo; Zhang, Xin; Zhao, Yuhua

2016-02-01

Polybrominated diphenyl ethers (PBDEs) are known as ubiquitous pollutants in ecological systems and thus pose a great threat to the health of humans and other organisms due to their bioamplification and bioaccumulation along the food chain. The present study was designed to investigate the biosorption capacity of biochar for the removal of 4-monobromodiphengl ether and its synergistic effect when used as a carrier to immobilize the 4-monobromodiphengl ether-degrading strain Sphingomonas sp. DZ3. The raw biochar material was prepared by pyrolyzing maize straw at 350 °C under oxygen-limited conditions. The maximum biosorption capacity of biochar for 4-bromodiphengl ether was determined to be 50.23 mg/L under an initial concentration of 800 mg/L at pH 7.0 and 40 °C. The data obtained from the biosorption studies were fitted successfully with the pseudo-first-order kinetic and Freundlich isotherm models. The Weber-Morris model analysis indicated that intraparticle diffusion was the limiting step in the biosorption of 4-bromodiphengl ether onto the biosorbent. The values of thermodynamic parameters △G0 were calculated as -24.61 kJ/mol (20 °C), -24.35 kJ/mol (30 °C), and -23.98 kJ/mol (40 °C), △S(0) was -8.45 kJ/mol/K, and △H(0) was 21.36 kJ/mol. The artificial neural network analysis indicated that the initial concentration appeared to be the most influential parameter on the biosorption processes. The removal rate of 4-bromodiphengl ether achieved using the biochar-microorganism system was increased by 63 and 83% compared with the rates obtained with biochar and the strain individually, respectively. The morphology of the biochar and immobilized strain was determined using a scanning electron microscope, and information of the surface functional groups of biochar was obtained through an infrared spectra study.

Phytoextraction of toxic trace elements by Sorghum bicolor inoculated with Streptomyces pactum (Act12) in contaminated soils.

PubMed

Ali, Amjad; Guo, Di; Mahar, Amanullah; Wang, Ping; Ma, Fang; Shen, Feng; Li, Ronghua; Zhang, Zengqiang

2017-05-01

The increasing industrial, mining and agricultural activities have intensified the release of potential toxic trace elements (PTEs), which are of great concern to human health and environment. The alarming increase in PTEs concentration, stress the need for biotechnological remediation approaches. In order to assist phytoextraction of PTEs, different combinations of Streptomyces pactum (Act12) with biochar were applied to mining and industrial polluted soils of Shaanxi and Hunan Provinces of China, respectively. Act12 affected soil physico-chemical properties in both soils. Bioavailable Zn and Pb increased due to microbial activities, while Cd decreased by adsorption on biochar surface. Phytoextraction of Zn and Pb occurred in TG and CZ soil, while Cd uptake decreased in iron rich CZ soil by conflicting effect of siderophores. Cd in sorghum shoot was below detection level, but uptake increased in the roots due to minimum available fraction in TG soil. Biochar reduced the shoot and root uptake of Cd. Sorghum shoot, root dry weight and chlorophyll significantly increased after Act12 and biochar application. β-glucosidase, alkaline phosphatase and urease activities were significantly enhanced by Act12. Antioxidant enzymatic activities (POD, PAL and PPO) and lipid peroxidation (MDA) were decreased after the application of Act12 and biochar by reduced PTEs stress. Act12 and biochar can be used for different crops to enumerate the transfer rate of PTEs into the food chain. Copyright © 2017 Elsevier Inc. All rights reserved.

Contrasting agronomic response of biochar amendment to a Mediterranean Cambisol: Incubation vs. field experiment

NASA Astrophysics Data System (ADS)

De la Rosa, José M.; Paneque, Marina; De Celis, Reyes; Miller, Ana Z.; Knicker, Heike

2015-04-01

The application of biochar to soil is being proposed as a novel approach to establish a significant long-term sink for atmospheric carbon dioxide in terrestrial ecosystems. In addition, biochars offer a simple, sustainable tool for managing organic wastes and to produce added value products. Numerous research studies pointed out that biochar can act as a soil conditioner enhancing plant growth by supplying and, more importantly, retaining nutrients and by providing other services such as improving soil physical and biological properties [1]. However, the effectiveness of biochar in enhancing plant fertility is a function of soil type, climate, and type of crop [2] but also of the biochar properties. The inherent variability of biochars due to different feedstock and production conditions implies a high variability of their effect on soil properties and productivity. Furthermore, due to the irreversibility of biochar application, it is necessary to perform detailed studies to achieve a high level of certainty that adding biochar to agricultural soils, for whatever reason, will not negatively affect soil health and productivity. The major goals of this research were: i) understanding how the properties of 5 different biochars produced by using different feedstock and pyrolysis conditions are related to their agronomic response, and ii) assessing the agronomic effect of biochar amendment under field conditions of a typical Mediterranean non-irrigated plantation. Four of the used biochars were produced by pyrolysis from wood (2), paper sludge (1) and sewage sludge (1), at temperatures up to 620 °C. The fifth biochar was produced from old grapevine wood by applying the traditional kiln method. Biochars were analysed for elemental composition (C, H, N), pH, WHC and ash contents. The H/C and O/C atomic ratios suggested high aromaticity of all biochars, which was confirmed by 13C solid-state NMR spectroscopy. The FT-IR spectra indicated the presence of lignin residues in wood biochars. The FESEM-EDS distinguished compositional and structural differences of the studied biochars such as macropores on the surface of pyrolysis wood biochars. In the frame of a pot experiment, the biochar characteristics (physical properties and chemical composition) were related to the germination rates and to the plant biomass production of a Lolium perenne. Incubation was carried out in 300 mL pots during 79 days in which a calcic Cambisol [3] was amended with 10, 20 and 40 t ha-1 biochar. After adjusting the soil humidity to 60% of the maximum water holding capacity (WHC), the pots were placed into a greenhouse under similar conditions than those reported by [4]. Biochar amendment improved significantly germination rates and soil fertility (excepting kiln wood biochar), and had no negative pH impact on the already alkaline soil. Application of sewage sludge biochar, the richest in minerals and nitrogen, resulted in the highest soil fertility. In this case, increase of the dose went along with an enhancement of plant production. Considering further costs due to production and transport of biochar, the application of 10 t ha-1 turned out as the most efficient for the crop and soil used in the incubation experiment [further details in 5]. The field study was performed with seeds of Helianthus annuus, at the experimental station "La Hampa", located in the Guadalquivir river valley (SW Spain; 37° 21.32' N, 6° 4.07' W), Seville. The calcic Cambisol which was also used as matrix for the pot experiments was amended with doses equivalent to 0 (control), 1.5 and 15 t ha-1 of the five biochars, making a total of 12 different treatments. Soil properties and composition were monitored during the growing time including elemental composition, pH, water holding capacity and soil microbial biomass. After 6 months of growth, sunflower plants were harvested. Plant height, chlorophyll content and sunflower seeds production were recorded. Results of this field experiment are still being processed. Nevertheless, preliminary results indicated that addition of biochar did not alter negatively physical properties (pH, EC) or composition of this alkaline soil, on the contrary biochar addition caused a slight improvement of the WHC and soil porosity. Those changes produced a faster development of plant shoots. However, at the end of the experiment, biochar amendment caused no significant increase on the agronomic production for any of the tested biochars. From these preliminary results, we conclude that biochar amendment improved physical-surficial characteristics of the calcic Cambisol from an agronomic point of view, but under the typical Mediterranean climate those changes seem to leave the harvested seed yields unaffected. References: [1] Glaser B, Lehmann J, Zech W, 2002. Biol. Fert. Soils. 35, 219-230. [2] Blackwell P, Riethmuller G, Collins M, 2009. in Lehmann J, Joseph S. Earthscan (Eds.), Biochar for Environmental Management: Science and Technology, London. [3] IUSS Working Group WRB, 2007. World Soil Resources Reports 103. FAO, Rome. [4] De la Rosa JM, Knicker H, 2011. Soil Biol. Biochem. 43, 2368-2373. [5] De la Rosa JM, Paneque M, Miller AZ, Knicker H, 2014. Sci. of the Tot. Env. 499, 175-184. Acknowledgements: The Marie Skłodowska-Curie actions (REA grant agreement n° PCIG12-GA-2012-333784-Biocharisma project) and the Spanish Ministry of Economy and Competitiveness (MINECO) (project PCGL2012-37041) are thanked for the financial support of the present study. The "Fondo Social Europeo" is thanked for funding J.M de la Rosa JAE-Doc contract. The European Biochar Network (Biochar as option for sustainable resource management-COST action TD1107) and Bodegas Torres (Spain) are acknowledged for providing the biochar samples.

Analytical high resolution microscopic investigation of organic coating on co-composted biochar

NASA Astrophysics Data System (ADS)

Albu, Mihaela; Mayrhofer, Claudia; Hagemann, Nikolas; Joseph, Stephen; Hofer, Ferdinand; Kothleitner, Gerald

2017-04-01

Aged and/or co-composted biochar amendment improves soil fertility by changing certain proprieties like the porosity and sorption capacity, the redox properties, water holding capacity and nutrient transformations in soil. The beneficial properties have been correlated with surface functional groups resulting from the interactions between black carbon particles, inorganic and organic matter in the soil and soil biota, manure or other compost feedstock. As a result, porous organic layer and organo-mineral phases on the biochar surfaces are formed. This paper presents a detailed analysis of the porous layer and organo-mineral phases formed on co-composted biochar by using high resolution scanning transmission electron microscopy (STEM) and electron energy loss (EELS) as well as energy dispersive X-ray spectroscopy (EDX). The fine structure fingerprints of carbon and nitrogen edges have been used to identify the functional groups, while EDX was used to identify the mineral phases. However, in order to achieve undoubtable results a novel preparation technic of the sample has been developed. The preparation involved 3D gold sputtering on the black carbon particles in order to preserve the surface intact, embedding in resin and, ultrathin microtome cutting. The investigation was carried out using a probe corrected Titan 3G, at a voltage of 60 kV and in cryo-condition, with an EELS energy resolution of 0.15 eV and a spatial resolution down to atomic layers. We proved the presence of both C and N functional groups in the porous, heterogeneous and hydrophilic organic layer and organo-mineral agglomerates. The organic layer fully covered the outer surface of the black carbon piece, but also the surface of internal pores. Its thickness varied from 500-1000 nm on the outer surface down to a couple of nanometres on internal pores. The observed C functional groups have been identified to correspond to: aromatic, aromatic with side chain, ketone, aliphatic, carboxyl/amine carbon and, carbonyl while the N functional groups were: pyridine, imine, amide/peptide, pyrrole, and NO2-/oxidised N. The STEM analysis also revealed the formation of complex organo-mineral agglomerates involving Ca but also the redox-active Fe as iron oxide nnanoparticles and P as magnesium phosphate nnanoparticles. These findings are valuable information which contributes to the understanding of biochar reactions with soil and plants as a function of agronomic practice and environmental factors. Acknowledgment This research received funding from the European Union Seventh Framework Programme under Grant Agreement 312483 - ESTEEM2 (Integrated Infrastructure Initiative-I3).

Biochar Supported Nanoscale Iron Particles for the Efficient Removal of Methyl Orange Dye in Aqueous Solutions

PubMed Central

Zhao, Shichen; Yan, Jingchun; Qian, Linbo; Chen, Mengfang

2015-01-01

The presence of organic contaminants in industrial effluents is an environmental concern of increasing global importance. One innovative technology for treating contaminated industrial effluents is nanoscale zero-valent iron supported on biochar (nZVI/BC). Based on Transmission Electron Microscopy, X-Ray Diffraction, and Brunauer-Emmett-Teller characterizations, the nZVI was well dispersed on the biochar and aggregation was dramatically reduced. Methyl orange (MO) served as the representative organic contaminant for verifying the effectiveness of the composite. Using decolorization efficiency as an indicator of treatment effectiveness, increasing doses of nZVI/BC yielded progressively better results with 98.51% of MO decolorized by 0.6 g/L of composite at an nZVI/BC mass ratio of 1:5. The superior decolorization efficiency of the nZVI/BC was attributed to the increase in the dispersion and reactivity of nZVI while biochar increasing the contact area with contaminant and the adsorption of composites. Additionally, the buffering function of acid-washed biochar could be in favor of maintaining the reactivity of nZVI. Furthermore, the aging nZVI/BC for 30 day was able to maintain the removal efficiency indicating that the oxidation of nZVI may be delayed in the presence of biochar. Therefore, the composite of nZVI/BC could represent an effective functional material for treating wastewater containing organic dyes in the future. PMID:26204523

Immobilization of copper by biochar in Cu-enriched agricultural soils depends on interactions with soil organic carbon

NASA Astrophysics Data System (ADS)

Mlinkov, Slađana; Zehetner, Franz; Rosner, Franz; Dersch, Georg; Soja, Gerhard

2017-04-01

The appearance of downy mildew (Plasmopara viticola) in European vineyards of the 19th century was the starting point for the search of effective fungicides to avoid severe yield losses. Copper has been found as an important ingredient for several fungicides that have been used in agriculture and horticulture. For organic viticulture, several diseases can only be antagonized with Cu-containing fungicides as the application of organic fungicides is not permitted. This long-lasting dependence on Cu-fungicides has led to a gradual Cu enrichment of vineyard soils in traditional wine-growing areas, locally exceeding 300 mg/kg. Although these concentrations do not affect the vines or wine quality, they may impair soil microbiological functions in the top soil layer or the root growth of green cover plants. Therefore, measures are demanded that reduce the bioavailability of copper, thereby reducing the ecotoxicological effects. The use of biochar and compost as soil amendment has been suggested as a strategy to immobilize Cu and reduce the exchangeable fractions. In our study we have tested the hypothesis that biochar immobilizes the bioavailability of Cu for soil cover crops and reduces soil pore water concentrations. This study had the objective to test the interactions of compost and biochar with respect to Cu immobilization in vineyard soils. A Cu-enriched vineyard soil (250 mg Cu kg-1) was analyzed both in greenhouse and field experiments. In both experiments, soil with or without biochar and/or compost and mixtures of the two components were used. In the greenhouse experiments, was used as test plant Lolium multiflorum for Cu uptake; in the field, Lolium perenne and Trifolium repens were analyzed. Greenhouse experiment: Soil pore water concentrations showed clearer differences in Cu concentration than Lolium multiflorum shoots. Compost increased dissolved organic carbon (DOC) and Cu in soil pore water and biochar reduced it significantly. The mixtures of compost and biochar produced intermediate results. Field experiment: Cu concentrations in the roots of soil cover crops were higher than above-ground parts. Biochar as soil additive (4 kg m-2) and a biochar-compost mixture at a high application rate (10 kg m-2) reduced the Cu uptake into the roots. Compost without biochar or the mixture at a lower dose (4 kg m-2) either had no or even a mobilizing effect on Cu. Apparently the effects of compost and biochar are opposite. Biochar is only able to exert an immobilizing effect if soil organic carbon content is not too high; otherwise only very high biochar addition rates can counteract the effect of compost. .

Kinetic characteristic of phenanthrene sorption in aged soil amended with biochar

NASA Astrophysics Data System (ADS)

Kim, Chanyang; Kim, Yong-Seong; Hyun, Seunghun

2015-04-01

Biochar has been recently highlighted as an amendment that affects yield of the crops by increasing pH, cation exchange capacity and water retention, and reduces the lability of contaminants by increasing sorption capacity in the soil system. Biochar's physico-chemical properties, high CEC, surfaces containing abundant micropores and macropores, and various types of functional groups, play important roles in enhancing sorption capacity of contaminants. Aging through a natural weathering process might change physico-chemical properties of biochar amended in soils, which can affect the sorption behavior of contaminants. Thus, in this study, the sorption characteristics of phenanthrene (PHE) on biochar-amended soils were studied with various types of chars depending on aging time. To do this, 1) soil was amended with sludge waste char (SWC), wood char (WC), and municipal waste char (MWC) during 0, 6, and 12 month. Chars were applied to soil at 1% and 2.5% (w/w) ratio. 2) Several batch kinetic and equilibrium studies were conducted. One-compartment first order and two-compartment first order model apportioning the fraction of fast and slow sorbing were selected for kinetic models. Where, qt is PHE concentration in biochar-amended soils at each time t, qeis PHE concentration in biochar-amended soils at equilibrium. ff is fastly sorbing fraction and (1-ff) is slowly sorbing fraction. k is sorption rate constant from one-compartment first order model, k1 and k2 are sorption rate constant from two-compartment first order model, t is time (hr). The equilibrium sorption data were fitted with Fruendlich and Langmuir equation. 3) Change in physico-chemical properties of biochar-amended soils was investigated with aging time. Batch equilibrium sorption results suggested that sorbed amount of PHE on WC was greater than SWC and MWC. The more char contents added to soil, the greater sorption capacity of PHE. Sorption equilibrium was reached after 4 hours and equilibrium pH ranged from 6.5 to 8.0. Sorption capacity was reduced with aging time. From kinetic results, two-compartment first order model was more suitable than one-compartment first order model. Fast sorption site of biochar-amended soils dominated total sorption process (i.e., Fraction of fast sorption site ranged from 0.55 to 0.96). Reduced sorption capacity with aging time could be attributed to changes in physico-chemical properties of biochar-amended soils (e.g., reduced pores and increased hydrophilic carboxyl and carbonyl functional groups). Verification is FI-IR and SSA. It is assumed that biochar is a suitable material for PHE contaminated soil in order to reduce the lability of PHE. However, aging effects would lessen biochar benefit for reducing the sorption capacity of PHE by forming hydrophilic functional group and reducing pores.

Biochar contribution to soil pH buffer capacity

NASA Astrophysics Data System (ADS)

Tonutare, Tonu; Krebstein, Kadri; Utso, Maarius; Rodima, Ako; Kolli, Raimo; Shanskiy, Merrit

2014-05-01

Biochar as ecologically clean and stable form of carbon has complex of physical and chemical properties which make it a potentially powerful soil amendment (Mutezo, 2013). Therefore during the last decade the biochar application as soil amendment has been a matter for a great number of investigations. For the ecological viewpoint the trend of decreasing of soil organic matter in European agricultural land is a major problem. Society is faced with the task to find possibilities to stabilize or increase soil organic matter content in soil and quality. The availability of different functional groups (e.g. carboxylic, phenolic, acidic, alcoholic, amine, amide) allows soil organic matter to buffer over a wide range of soil pH values (Krull et al. 2004). Therefore the loss of soil organic matter also reduces cation exchange capacity resulting in lower nutrient retention (Kimetu et al. 2008). Biochar can retain elements in soil directly through the negative charge that develops on its surfaces, and this negative charge can buffer acidity in the soil. There are lack of investigations about the effect of biochar to soil pH buffering properties, The aim of our investigation was to investigate the changes in soil pH buffer capacity in a result of addition of carbonizated material to temperate region soils. In the experiment different kind of softwood biochars, activated carbon and different soil types with various organic matter and pH were used. The study soils were Albeluvisols, Leptosols, Cambisols, Regosols and Histosols . In the experiment the series of the soil: biochar mixtures with the biochar content 0 to 100% were used. The times of equiliberation between solid and liquid phase were from 1 to 168 hours. The suspension of soil: biochar mixtures was titrated with HCl solution. The titration curves were established and pH buffer capacities were calculated for the pH interval from 3.0 to 10.0. The results demonstrate the dependence of pH buffer capacity from soil type, organic matter and type of added carbonizated material. Our study showed that the biochar content has significant role in total pH buffer capacity in soil:biochar system . References. Kimetu, J.M., Lehmann, J., Ngoze, S.O., Mugendi, D.N., Kinyangi, J., Riha, S.J., Verchot, L., Recha, J.W., Pell, A.N. 2008. Reversibility of Soil Productivity Decline with Organic Matter of Differing Quality Along a Degradation Gradient. Ecosystems, 11, 726-739. Krull, E. S., Skjemstad, J.O., Baldock, J.A. 2004 'Functions of Soil Organic Matter and the Effect on Soil Properties'. GRDC report. Project CSO 00029. Mutezo, W.T., 2013. Early crop growth and yield responses of maize (Zea mays) to biochar applied on soil. International Working Paper Series, 13/03, 50 pp.

Biochar-supported reduced graphene oxide composite for adsorption and coadsorption of atrazine and lead ions

NASA Astrophysics Data System (ADS)

Zhang, Ying; Cao, Bo; Zhao, Lulu; Sun, Lili; Gao, Yan; Li, Jiaojiao; Yang, Fan

2018-01-01

To explore potential in application for simultaneous removal of atrazine and lead ions (Pd2+), the adsorption and coadsorption of atrazine and Pd2+ is evaluated onto a novel biochar-supported reduced graphene oxide composite (RGO-BC), which has been successfully developed via slow pyrolysis of graphene oxide (GO) pretreated corn straws. Structure and morphology analysis reveal that GO nanosheets are coated on the surface of biochar (BC) mainly through π-π interactions, notably, GO nanosheets after annealing reduction can basically retain the original morphology, meanwhile, the change of physico-chemical properties on the surface endow excellent adsorption capaities of 26.10 mg g-1 for Pb2+ and 67.55 mg g-1 for atrazine. A significant difference is in sorption of Pb2+ and atrazine on RGO-BC sample in both single- and binary-solute systems. The adsorption capacity of RGO-BC still remained above 54.58 mg g-1 after four times regeneration (81% adsorption capacity remained), demonstrating a promising candidate for the application of removal contaminant in the environment.

Biochar in viticulture

NASA Astrophysics Data System (ADS)

Niggli, C.; Schmidt, H.-P.

2012-04-01

Viticulture is becoming the pioneering culture for biochar research. Biochar has been applied to many large-scale viticulture experiments across Europe this spring. After the first large-scale and long term experiments at the Delinat Institute in 2007-08, expectations are high. The latest results confirm these expectations and also show that only scientifically sound experiments will lead to conclusive information on the effect of biochar on vine growth and wine quality in many different climates and soil types. In the last three years it has been clearly shown that biologically activated biochar does not only have positive impact on soil-plant systems in the tropics, but in all soil types and climatic zones [Crane Droescher [2011], Ogawa [2010], IBI [2011]). While biochar improves water availability for plants and microorganisms in dry or seasonally dry farming areas, it also plays a substantial role in high rainfall zones because it improves nutrient dynamics through prevention of nutrient leaching. Spectacular crop growth can be seen in extreme climates (tropical or semi-desert), partly due to biochar's buffering capacity leading to the compensation of strong limiting factors (water in semi-deserts, washed-out nutrients in the tropics). In temperate climates, however, the achievable increase in harvest is lower as there are no extremely limiting elements which have to be compensated. In addition, potential maximum growth of many plant species is easily reached in temperate zones through using good fertilizers and careful seed selection. Therefore the advantage of biochar application in temperate climates is less evident as crop growth but rather is seen as plant quality improvement through optimizing plant nutrition. 1. Increase of plant resistance and hence reduction of plant protection products 2. Stimulation of soil microbial activity and symbioses between plants and soil organisms 3. Reduction in fertilizer use by optimizing the supply of nutrients, limiting nutrient losses 4. Improvement of taste and nutrient content of the crop 5. Improvement of shelf life 6. Reduction of greenhouse gas emissions and groundwater pollution Biochar is not a fertilizer, but rather a nutrient carrier and a habitat for microorganisms. If biochar is incorporated pure and without activation into the soil, its high adsorption capacity and increasing CEC will result in the absorption and fixing of available nutrients and water in the soil. This may lead to inhibition of plant growth, at least in the beginning (several months to a year), depending on the soil's nutrient content. Biochar needs to be charged to become biologically active in order to efficiently utilize its soil-enhancing properties. There are numerous methods of activating and producing substrates similar to terra preta aside from mixing biochar with compost. A new field experiment has been established in the vineyards of Delinat-Institute in 2011 to study the effects of biochar incorporation into compost preliminary to the composting process. Other field trials with manure-activated biochar were conducted this year by more than 15 companies in several major wine regions in Europe and first results have been evaluated.

A Combination of Biochar-Mineral Complexes and Compost Improves Soil Bacterial Processes, Soil Quality, and Plant Properties.

PubMed

Ye, Jun; Zhang, Rui; Nielsen, Shaun; Joseph, Stephen D; Huang, Danfeng; Thomas, Torsten

2016-01-01

Organic farming avoids the use of synthetic fertilizers and promises food production with minimal environmental impact, however this farming practice does not often result in the same productivity as conventional farming. In recent years, biochar has received increasing attention as an agricultural amendment and by coating it with minerals to form biochar-mineral complex (BMC) carbon retention and nutrient availability can be improved. However, little is known about the potential of BMC in improving organic farming. We therefore investigated here how soil, bacterial and plant properties respond to a combined treatment of BMC and an organic fertilizer, i.e., a compost based on poultry manure. In a pakchoi pot trial, BMC and compost showed synergistic effects on soil properties, and specifically by increasing nitrate content. Soil nitrate has been previously observed to increase leaf size and we correspondingly saw an increase in the surface area of pakchoi leaves under the combined treatment of BMC and composted chicken manure. The increase in soil nitrate was also correlated with an enrichment of bacterial nitrifiers due to BMC. Additionally, we observed that the bacteria present in the compost treatment had a high turnover, which likely facilitated organic matter degradation and a reduction of potential pathogens derived from the manure. Overall our results demonstrate that a combination of BMC and compost can stimulate microbial process in organic farming that result in better vegetable production and improved soil properties for sustainable farming.

Biochar Amendment to the Soil Surface Reduces Fumigant Emissions and Enhances Soil Microorganism Recovery.

PubMed

Shen, Guoqing; Ashworth, Daniel J; Gan, Jay; Yates, Scott R

2016-02-02

During soil fumigation, it is ideal to mitigate soil fumigant emissions, ensure pest control efficacy, and speed up the recovery of the soil microorganism population established postapplication. However, no current fumigant emission reduction strategy can meet all these requirements. In the present study, replicated soil columns were used to study the effect of biochar derived from rice husk (BR) and green waste (BG) applied to the soil surface on 1,3-dichloropropene (1,3-D) and chloropicrin (CP) emissions and soil gas distribution, and on microorganism population re-establishment. Relative to fumigated bare soil (no emission reduction strategy), high-density polyethylene (HDPE), and ammonium thiosulfate (ATS) treatments, BR gave dramatic emission reductions for both fumigants with no obvious emission peak, whereas BG was very effective only for 1,3-D. With BR application, the concentration of fumigant in the soil gas was higher than in the bare soil and ATS treatment. After the soil column experiment, mixing the BR with the fumigated soil resulted in higher soil respiration rates than were observed for HDPE and ATS treatments. Therefore, biochar amendment to the soil surface may be an effective strategy for fumigant emission reduction and the recovery of soil microorganism populations established postapplication.

Nitrogen-functionalization biochars derived from wheat straws via molten salt synthesis: An efficient adsorbent for atrazine removal.

PubMed

Yang, Fan; Sun, Lili; Xie, Weiling; Jiang, Qun; Gao, Yan; Zhang, Wei; Zhang, Ying

2017-12-31

N-doped porous carbon sheets (NPCS) resulted from wheat straws are fabricated through using molten salts via the carbonization-functionalization progress, which show unique hierarchical structure, large pore volume and high surface area with affluent micropores. Results indicate that there exist many hierarchical pores consisting of the single carbon sheet with ultrathin nature, owing to the template role of molten salt mixtures at high temperature. Such superior structure can bring about desired performance of adsorption capacity of 82.8mg/g and quick adsorption rate of 1.43L/(gh) with an initial concentration of 35mg/L at 25°C. Langmuir and Freundlich models are adopted to interpret the adsorption behavior of atrazine and modified Freundlich and intraparticle diffusion (IPD) models are employed to characterize the dynamics of adsorption. Furthermore, nitrogen-functionalization biochars via molten salt synthesis should be further developed as a one-pot methodology to produce N-doped carbons, opening up a feasible approach for resource utilization of crop straws and other biomass wastes. Copyright © 2017 Elsevier B.V. All rights reserved.

Pyrolysis polygeneration of poplar wood: Effect of heating rate and pyrolysis temperature.

PubMed

Chen, Dengyu; Li, Yanjun; Cen, Kehui; Luo, Min; Li, Hongyan; Lu, Bin

2016-10-01

The pyrolysis of poplar wood were comprehensively investigated at different pyrolysis temperatures (400, 450, 500, 550, and 600°C) and at different heating rates (10, 30, and 50°C/min). The results showed that BET surface area of biochar, the HHV of non-condensable gas and bio-oil reached the maximum values of 411.06m(2)/g, 14.56MJ/m(3), and 14.39MJ/kg, under the condition of 600°C and 30°C/min, 600°C and 50°C/min, and 550°C and 50°C/min, respectively. It was conducive to obtain high mass and energy yield of bio-oil at 500°C and higher heating rate, while lower pyrolysis temperature and heating rate contributed towards obtaining both higher mass yield and energy yield of biochar. However, higher pyrolysis temperature and heating rate contributed to obtain both higher mass yield and energy yield of the non-condensable gas. In general, compared to the heating rate, the pyrolysis temperature had more effect on the product properties. Copyright © 2016 Elsevier Ltd. All rights reserved.

Biochar-amended filter socks reduce herbicide losses via tile line surface inlets

USDA-ARS?s Scientific Manuscript database

Standing water in depressions and behind terraces in fields with subsurface drainage systems can result in reduced crop yields. This concern can be partially alleviated by installing surface inlets that reduce the duration of ponding. Unfortunately, these inlets provide an open conduit for surface w...

Impact of drying-rewetting events on the response of soil microbial functions to dairyfibre and Miscanthus biochars

NASA Astrophysics Data System (ADS)

Bonnett, Sam; Vink, Stefanie; Baker, Kate; Saghir, Muhammad; Hornung, Andreas

2014-05-01

Biochar application has been shown to positively affect soil microbial functions such as reducing greenhouse gas emissions, increasing water/nutrient availability and increasing crop yields in tropical regions (Lehmann & Joseph, 2009). Understanding the dynamics of biochar application to soil microbial processes is critical for ensuring that soil quality, integrity and sustainability of the soil sub-system are maintained for crop growth. The aim of this British Ecological Society (BES) funded study was to examine the effect of two types of biochar on soil physicochemistry, GHG production, soil enzyme activities and microbial biomass in typical agricultural soil types and whether the effects were altered by drying, rewetting and flooding events. Miscanthus and dairyfibre (a mixture of straw and manure) feedstocks from Harper Adams University were pyrolyzed by Aston University at 450 °C using 100 kg/hr pyroformer technology. Two sieved soil types (sandy loam and clay loam) were mixed with dry biochar to produce 2 and 10 % w/w treatments for comparison with controls and maintained at 15 °C in temperature controlled incubators. At 0, 22, 44, 80, 101, and 114 days, soil was collected for determination of heterotrophic respiration, and microbial biomass by substrate-induced respiration (SIR), by gas headspace incubation and analysis of carbon dioxide (CO2) and nitrous oxide (N2O) by gas chromatography. Soil was sampled for the determination of water-extractable carbon, pH, and extracellular enzyme activities. Soil samples were maintained at field gravimetric water content between 0 and 44 days; air dried between 44 and 80 days; rewetted between 80 and 101 days; and flooded between 101 to 114 days. Results showed that the impact of biochar on soil microbial processes was dependent on biochar type and soil type, the level of biochar application and changes in soil moisture. Biochar affected soil pH particularly within the dairyfibre treatments, potentially due to the dissolution of alkaline minerals, high ash content (Lehmann et al. 2011) and solubility of DOC. Biochar treatments buffered changes in pH caused by drying and flooding but resulted in an increase in DOC. Biochar in general stabilised glucosidase activity whilst Miscanthus biochar stimulated chitinase and phosphatase activity that may have been due to adsorption of either enzyme or substrate as observed by Bailey et al. (2011). Surprisingly, alkaline phosphatase activity was not stimulated by the rise in pH in the diaryfibre treatment and was lower than the control along with the other hydrolase enzymes suggesting that deprotonation of soil phenols at higher pH inhibited activity via the enzyme-latch mechanism that in peatlands explains low rates of decomposition (Freeman et al., 2001; Sinsabaugh et al. 2010). This was supported by observation of higher phenol oxidase activity within the dairyfibre treatment that increased in response to greater availability of substrate and/or increases in pH. All biochars inhibited the production of N2O that was stimulated by the supply of labile carbon from SIR, suggesting that biochar decreased C-substrate availability through adsorption at its surface (Clough and Condron, 2010). Overall, this study has shown that specific feedstocks may be used to produce biochars to control microbial functions in soil such as inhibiting hydrolase enzymes for carbon sequestration as occurs naturally in peatlands or suppress the production of the potent greenhouse gas N2O. References Bailey, V., Fansler, S.J., Smith, J.L. Bolton, H. (2011) Reconciling apparent variability in effects of biochar amendment on soil enzyme activities by assay optimization. Soil Biology and Biochemistry 43, 296-301. Clough, T. and Condron, L. (2010) Biochar and the nitrogen cycle: introduction. Journal of Environmental Quality, 39,1218-1223. Freeman, C., Ostle, N. and Kang, H. (2001) An enzymic 'latch' on a global carbon store. Nature 409, 149. Lehmann, J and Joseph, S (2009). Biochar for Environmental Management. Earthscan, London. Lehmann, J., Rillig, M.C., Thies, J., Masiello, C.A., Hockaday, W.C. and Crowley, D. (2011) Biochar effects on soil biota - A review. Soil Biology and Biochemistry 43, 1812-1836. Sinsabaugh, R.L. (2010) Phenol oxidase, peroxidase and organic matter dynamics of soil. Soil Biology and Biochemistry 42, 391-404.

Effect of biochar and Fe-biochar on Cd and As mobility and transfer in soil-rice system.

PubMed

Yin, Daixia; Wang, Xin; Peng, Bo; Tan, Changyin; Ma, Lena Q

2017-11-01

In this study, the effects of biochar derived from rice-straw (biochar) and iron-impregnated biochar (Fe-biochar) on Cd and As mobility in rice rhizosphere and transfer from soil to rice were investigated with different application rates. 1-3% biochar reduced porewater Cd in rhizosphere but elevated soluble As, resulting in 49-68% and 26-49% reduction in the root and grain Cd, with a simultaneous increase in root As. Unlike biochar, 0.5% Fe-biochar decreased porewater As throughout rice growth, resulting in reduced root As, which, however, increased Cd uptake by root. Biochar-induced soil As mobilization was probably through competitive desorption and Fe-biochar-induced soil Cd mobilization was probably via soil acidification. The results suggested that biochar and Fe-biochar was effective in reducing Cd and As uptake by rice, respectively, so they may be used as emergency measures to cope with single Cd or As contamination in paddy soils. Copyright © 2017. Published by Elsevier Ltd.

Influence of feedstock on the copper removal capacity of waste-derived biochars.

PubMed

Arán, Diego; Antelo, Juan; Fiol, Sarah; Macías, Felipe

2016-07-01

Biochar samples were generated by low temperature pyrolysis of different types of waste. The physicochemical characteristics of the different types of biochar affected the copper retention capacity, by determining the main mechanism involved. The capacity of the biochar to retain copper present in solution depended on the size of the inorganic fraction and varied in the following order: rice biochar>chicken manure biochar>olive mill waste biochar>acacia biochar>eucalyptus biochar>corn cob biochar. The distribution of copper between the forms bound to solid biochar, dissolved organic matter and free organic matter in solution also depended on the starting material. However, the effect of pH on the adsorption capacity was independent of the nature of the starting material, and the copper retention of all types of biochar increased with pH. Copyright © 2016 Elsevier Ltd. All rights reserved.

Arsenic removal by Japanese oak wood biochar in aqueous solutions and well water: Investigating arsenic fate using integrated spectroscopic and microscopic techniques.

PubMed

Niazi, Nabeel Khan; Bibi, Irshad; Shahid, Muhammad; Ok, Yong Sik; Shaheen, Sabry M; Rinklebe, Jörg; Wang, Hailong; Murtaza, Behzad; Islam, Ejazul; Farrakh Nawaz, M; Lüttge, Andreas

2018-04-15

In this study, we examined the sorption of arsenite (As(III)) and arsenate (As(V)) to Japanese oak wood-derived biochar (OW-BC) in aqueous solutions, and determined its efficiency to remove As from As-contaminated well water. Results revealed that, among the four sorption isotherm models, Langmuir model showed the best fit to describe As(III) and As(V) sorption on OW-BC, with slightly greater sorption affinity for As(V) compared to As(III) (Q L =3.89 and 3.16mgg -1 ; R 2 =0.91 and 0.85, respectively). Sorption edge experiments indicated that the maximum As removal was 81% and 84% for As(III)- and As(V)-OW-BC systems at pH7 and 6, respectively, which decreased above these pH values (76-69% and 80-58%). Surface functional groups, notably OH, COOH, CO, CH 3 , were involved in As sequestration by OW-BC, suggesting the surface complexation/precipitation and/or electrostatic interaction of As on OW-BC surface. Arsenic K-edge X-ray absorption near edge structure (XANES) spectroscopy indicated that 36% of the added As(III) was partially oxidized to As(V) in the As(III) sorption experiment, and in As(V) sorption experiment, 48% of As(V) was, albeit incompletely, reduced to As(III) on OW-BC surface. Application of OW-BC to As-contaminated well water (As: 27-144μgL -1 ; n=10) displayed that 92 to 100% of As was depleted despite in the presence of co-occurring competing anions (e.g., SO 4 2- , CO 3 2- , PO 4 3- ). This study shows that OW-BC has a great potential to remove As from solution and drinking (well) water. Overall, the combination of macroscopic sorption data and integrated spectroscopic and microscopic techniques highlight that the fate of As on biochar involves complex redox transformation and association with surface functional moieties in aquatic systems, thereby providing crucial information required for implication of biochar in environmental remediation programs. Copyright © 2017 Elsevier B.V. All rights reserved.

Comparison of the effects of biochar and activating biochar application on selected soil properties

NASA Astrophysics Data System (ADS)

Dvořáčková, Helena; Záhora, Jaroslav; Elbl, Jakub; Kynický, Jindřich; Hladký, Jan; Brtnický, Martin

2017-04-01

In our experiment we worked with three different type of biochar. Biochar represents carbonized organic matter. Its influence on soil and plant grow strongly depend on feedstock and conditions during combusted process. Different types of biochar were compared by pot experiment: as substrate we used biochar from sewage sludge, biochar from residual biomass, activated biochar. Moreover two other variants were fertilized by digestate and mineral fertilizer - DAM 390 (mixture of ammonium and nitrate nitrogen). Lettuce Sativa L. was used as indicator plant and experiment was located in growth box. Activated biochar was prepared in water environment and activating took two weeks. Several studies have demonstrated that biochar can have toxic properties and its application to soil can negatively affect plant yield. This toxicity is cost by aromatic substances which are native part of biochar. The concentration of these substances depends especially on temperature during pyrolysis. Our aim was eliminate aromatic substance by application of biochar which were activated. The biomass production, mycorrhizal colonization and dehydrogenase enzymatic activity was determined after end of experiment. The significant differences in all parameters were found between conventional biochar and activating biochar. Above all we didn't found statistical different in dehydrogenase activity between all treatments except substrates with activated biochar where was activity third higher than in comparison with other variants. The presented results indicate that the production and use of activating biochar represents potential technology for decrease in toxicity of conventional biochar.

[Cd Runoff Load and Soil Profile Movement After Implementation of Some Typical Contaminated Agricultural Soil Remediation Strategies].

PubMed

Liu, Xiao-li; Zeng, Zhao-xia; Tie, Bai-qing; Chen, Qiu-wen; Wei, Xiang-dong

2016-02-15

Owing to the strong ability to immobilize and hyperaccumulate some toxic heavy metals in contaminated soils, the biochar, lime and such as hyperaccumulator ramie received increasing interests from crops and environment safety in recent years. Outdoor pot experiment was conducted to compare the impacts of lime and biochar addition in paddy rice treatment, hyperaccumulator ramie and ramie combined with EDTA of plant Phytoremediation methods on soil available Cd dynamics in rainfall runoff and the mobility along soil profile, under both natural acid precipitation and acid soil conditions. The results showed that, biochar addition at a 2% mass ratio application amount significantly increased soil pH, while ramie with EDTA application obviously decreased soil pH compared to ramie monoculture. Within the same rainfall events, water soluble Cd concentration in surface runoff of ramie treatments was significantly higher than those of waterlogged rice treatments, and Cd concentration in runoff was obviously increased after EDTA addition, whereas lime at a 0.3% mass ratio application amount as additive had no obvious impact on soil pH and Cd speciation change, which may be due to the low application amount. During the whole experimental period , water soluble Cd concentration of rainfall runoff in spring was higher than that in summer, showing the same seasonal characteristics in all treatments. Biochar addition could significantly decrease available Cd content in 0-20 cm soil layer and with certain preferable persistency effects, whereas EDTA addition treatment obviously increased available Cd of 0-20 cm soil layer compared to other treatments, and obvious Cd element activation phenomenon in 20-40 cm soil layer was observed after EDTA addition. In conclusion, lime and biochar as environmental and friendly alkaline Cd immobilization materials showed lower environment risk to surface and ground receiving water, but attention should be paid to phytoremediation enhanced with EDTA or other organic acid before promotion and field application for heavy metals removal from contaminated soils.

Use of Fe-Impregnated Biochar To Efficiently Sorb Chlorpyrifos, Reduce Uptake by Allium fistulosum L., and Enhance Microbial Community Diversity.

PubMed

Tang, Xiao-Yan; Huang, Wen-Da; Guo, Jing-Jing; Yang, Yang; Tao, Ran; Feng, Xu

2017-07-05

Fe-impregnated biochar was assessed as a method to remove the pesticide pollutant chlorpyrifos, utilizing biochar/FeO x composite synthesized via chemical coprecipitation of Fe 3+ /Fe 2+ onto Cyperus alternifolius biochar. Fe-impregnated biochar exhibited a higher sorption capacity than pristine biochar, resulting in more efficient removal of chlorpyrifos from water. Soil was dosed with pristine or Fe-impregnated biochar at 0.1 or 1.0% w/w, to evaluate chlorpyrifos uptake in Allium fistulosum L. (Welsh onion). The results showed that the average concentration of chlorpyrifos and its degradation product, 3,5,6-trichloro-2-pyridinol (TCP), decreased in A. fistulosum L. with increased levels of pristine biochar and Fe-biochar. Fe-biochar was found to be more effective in reducing the uptake of chlorpyrifos by improving the sorption ability and increasing plant root iron plaque. Bioavailability of chlorpyrifos is reduced with both biochar and Fe-biochar soil dosing; however, the greatest persistence of chlorpyrifos residues was observed with 1.0% pristine biochar. Microbial community analysis showed Fe-biochar to have a positive impact on the efficiency of chlorpyrifos degradation in soils, possibly by altering microbial communities.

Phosphorus sorption capacity of biochars varies with biochar type and salinity level.

PubMed

Dugdug, Abdelhafid Ahmed; Chang, Scott X; Ok, Yong Sik; Rajapaksha, Anushka Upamali; Anyia, Anthony

2018-02-10

Biochar is recognized as an effective material for recovering excess nutrients, including phosphorus (P), from aqueous solutions. Practically, that benefits the environment through reducing P losses from biochar-amended soils; however, how salinity influences P sorption by biochar is poorly understood and there has been no direct comparison on P sorption capacity between biochars derived from different feedstock types under non-saline and saline conditions. In this study, biochars derived from wheat straw, hardwood, and willow wood were used to compare P sorption at three levels of electrical conductivity (EC) (0, 4, and 8 dS m -1 ) to represent a wide range of salinity conditions. Phosphorus sorption by wheat straw and hardwood biochars increased as aqueous solution P concentration increased, with willow wood biochar exhibiting an opposite trend for P sorption. However, the pattern for P sorption became the same as the other biochars after the willow wood biochar was de-ashed with 1 M HCl and 0.05 M HF. Willow wood biochar had the highest P sorption (1.93 mg g -1 ) followed by hardwood (1.20 mg g -1 ) and wheat straw biochars (1.06 mg g -1 ) in a 25 mg L -1 P solution. Although the pH in the equilibrium solution was higher with willow wood biochar (~ 9.5) than with the other two biochars (~ 6.5), solution pH had no or minor effects on P sorption by willow wood biochar. The high sorption rate of P by willow wood biochar could be attributed to the higher concentrations of salt and other elements (i.e., Ca and Mg) in the biochar in comparison to that in wheat straw and hardwood biochars; the EC values were 2.27, 0.53, and 0.27 dS m -1 for willow wood, wheat straw, and hardwood biochars, respectively. A portion of P desorbed from the willow wood biochar; and that desorption increased with the decreasing P concentration in the aqueous solution. Salinity in the aqueous solution influenced P sorption by hardwood and willow wood but not by wheat straw biochar. We conclude that the P sorption capacity of the studied biochars is dependent on the concentration of the soluble element in the biochar, which is dependent on the biochar type, as well as the salinity level in the aqueous solution.

The influence comparing of activated biochar and conventional biochar on the soil biological properties

NASA Astrophysics Data System (ADS)

Dvořáčková, Helena; Mykajlo, Irina; Záhora, Jaroslav

2016-04-01

In our experiment we have used biochar. This material is the product of the pyrolysis that has shown a positive effect on numerous physical and chemical soil properties. However, its influence on the biological component of the soil is very variable. A number of toxic substances that inhibit the soil productivity may be produced during pyrolysis process. The experiment dealt with the hypothesis concerning biochar toxicity reduction by simulating natural processes in the soil. Biochar has been exposed to aeration in the aquatic environment, enriched with nutrients and a source of native soil microflora. It has been created 6 variants in total, each with four replications. The soils samples have been placed in a phytotron for 90 days. Variants consisted of the soil with fertilizers adding (compost, biochar, activated biochar) and have been prepared as well as variants containing compost and biochar and activated biochar optionally. The highest aboveground biomass production has been estimated in variants containing compost, while the lowest production - in the variants containing conventional biochar. During production comparing of the variants with the conventional biochar, activated biochar and control samples it has been evident that activated biochar promotes plant growth, and in contradiction conventional biochar inhibits it. We will approach to the same conclusions when comparing variants with a combination of conventional biochar + compost and activated biochar + compost. Mineral nitrogen leaching has been another investigated parameter. The highest leaching has occurred in the control variant, while the lowest - in the variant with activated biochar (the leaching of nitrate nitrogen has been negligeable). Our results suggest that activated biochar has the potential; however, it is necessary to carry out similar experiments in the field conditions.

A biochar-based medium in the biofiltration system: Removal efficiency, microorganism propagation, and the medium penetration modeling.

PubMed

Baltrėnas, Pranas; Baltrėnaitė, Edita; Kleiza, Jonas; Švedienė, Jurgita

2016-07-01

Biofiltration is a method of biological treatment belonging to cleaner technologies because it does not produce secondary air pollutants, but helps to integrate natural processes in microorganisms for decomposing volatile air pollutants and solving odor problems. The birch wood biochar has been chosen as a principal material for biofilter bed medium. The experiments were conducted at the temperatures of 24, 28, and 32 °C, while the concentration of acetone, xylene, and ammonium reached 300 mg/m(3) and the flow rate was 100 m(3)/hr. Before passing through the stage of the experimental research into the packing material inside biofilters, microorganisms were introduced. Four strains of microorganisms (including micromycetes Aspergillus versicolor BF-4 and Cladosporium herbarum 7KA, as well as yeast Exophiala sp. BF1 and bacterium Bacillus subtilis B20) were selected. At the inlet loading rate of 120 g/m(3)/hr, the highest elimination capacity of xylene in the biochar-based biofilter with the inoculated medium was 103 g/m(3)/hr, whereas that of ammonia was 102 g/m(3)/hr and that of acetone was 97 g/m(3)/hr, respectively. The maximum removal efficiency reached 86%, 85%, and 81%, respectively. The temperature condition (though characterized by some rapid changes) can hardly have a considerable influence on the biological effect (i.e., microbiological activity) of biofiltration; however, it can cause the changes in physical properties (e.g., solubility) of the investigated compounds. The birch biochar can be successfully used in the biofiltration system for propagation of inoculated microorganisms, biodegrading acetone, xylene, and ammonia. At the inlet loading rate of 120 g/m(3)/hr, the highest elimination capacity of xylene was 103 g/m(3)/hr, that of ammonia was 102 g/m(3)/hr, and that of acetone was 97 g/m(3)/hr, respectively. The morphological structure of biochar can be affected by the aggressive air contaminants, causing the change in the medium specific surface area, which is one of the factors controlling the biofilter performance. Although biological effects in biofiltration are typically considered to be more important than physical effects, the former may be more important for compounds with high Henry's Law coefficient values, and the biofilter design should thus provide conditions for better compound absorption.

Mobility and phytoavailability of As and Pb in a contaminated soil using pine sawdust biochar under systematic change of redox conditions.

PubMed

Beiyuan, Jingzi; Awad, Yasser M; Beckers, Felix; Tsang, Daniel C W; Ok, Yong Sik; Rinklebe, Jörg

2017-07-01

Biochar has been adopted to control the mobility and phytoavailability of trace elements (TEs) in soils. To date, no attempt has been made to determine the mobility and phytoavailability of arsenic (As) and lead (Pb) in a contaminated soil with biochars as amendments under predefined redox potentials (E H ). Thus, in this study, a soil contaminated with As and Pb (2047 and 1677 mg kg -1 , respectively) was pre-incubated for 105 days with three amendments (pine sawdust biomass (BM) and two biochars produced from the same feedstock at 300 °C (BC300) and 550 °C (BC550)). The aged samples were then exposed to dynamic E H conditions to evaluate the mobility and phytoavailability of As and Pb after immobilization. The BM amendment significantly decreased and the BC300 slightly reduced the mobility and phytoavailability of As and Pb, which may be related to the oxygen-containing functional groups on the surface of BM and BC300. In contrast, BC550 increased the mobility of As at -300 to -100 mV and 100 mV, enhanced the phytoavailability of As under oxidizing condition (>100 mV), but reduced the phytoavailability of Pb, which might be caused by the properties of amendments and redox chemistry of the TEs. The effectiveness of BM and biochars for the stabilization of As and Pb varied under dynamic E H conditions, which indicates that detailed investigations should be conducted before the applications of biochar as soil amendment under variable environmental conditions, especially for contaminated paddy soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

Agronomic benefits of biochar as a soil amendment after its use as waste water filtration medium.

PubMed

Werner, Steffen; Kätzl, Korbinian; Wichern, Marc; Buerkert, Andreas; Steiner, Christoph; Marschner, Bernd

2018-02-01

In many water-scarce countries, waste water is used for irrigation which poses a health risk to farmers and consumers. At the same time, it delivers nutrients to the farming systems. In this study, we tested the hypotheses that biochar can be used as a filter medium for waste water treatment to reduce pathogen loads. At the same time, the biochar is becoming enriched with nutrients and therefore can act as a fertilizer for soil amendment. We used biochar as a filter medium for the filtration of raw waste water and compared the agronomic effects of this "filterchar" (FC) and the untreated biochar (BC) in a greenhouse pot trial on spring wheat biomass production on an acidic sandy soil from Niger. The biochar filter showed the same removal of pathogens as a common sand filter (1.4 log units on average). We did not observe a nutrient accumulation in FC compared to untreated BC. Instead, P, Mg and K were reduced during filtration while N content remained unchanged. Nevertheless, higher biomass (Triticum L. Spp.) production in BC (+72%) and FC (+37%) treatments (20 t ha -1 ), compared with the unamended control, were found. There were no significant differences in aboveground biomass production between BC and FC. Soil available P content was increased by BC (+106%) and FC (+52%) application. Besides, mineral nitrogen content was reduced in BC treated soil and to a lesser extent when FC was used. This may be explained by reduced sorption affinity for mineral nitrogen compounds on FC surfaces. Although the nutrients provided by FC decreased, due to leaching in the filter, it still yielded higher biomass than the unamended control. Copyright © 2017 Elsevier Ltd. All rights reserved.

An investigation into the rapid removal of tetracycline using multilayered graphene-phase biochar derived from waste chicken feather.

PubMed

Li, Huiqin; Hu, Jingtao; Meng, Yue; Su, Jinhua; Wang, Xiaojing

2017-12-15

This study investigated the removal of tetracycline (TC) using multilayered graphene-phase biochar (MGB) derived from waste chicken feather. MGB was produced through a two-stage carbonization and KOH-activation method. MGB was characterized by scanning electron microscopy (SEM), transmission electron microscope (TEM), Fourier transform infrared (FT-IR), Raman spectra, Zeta potential and elemental analysis. Various chemical functional groups were demonstrated on the surface of MGB. MGB was featured by a very large BET surface area of 1838m 2 /g. A rapid equilibrium (within 30s) and an ultrahigh removal efficiency (up to 99.65%) were obtained when MGB was used in the adsorption of TCs. The adsorption processes were temperature-dependent and the maximum adsorption capacity of MGB was 388.33mg/g at 30°C. The data of adsorption isotherms and kinetics were represented well by the Langmuir and Elovich models, respectively. The chemical monolayer adsorption could play an important role in this process. Furthermore, the adsorption of MGB was tolerant with wide pH, high ionic strength and even co-existing anions. Regeneration experiments indicated the removal efficiency was still satisfied (96.61%) even after four cycles. These results have important implications for the future application of animal waste-derived adsorbents in the treatment of wastewater containing antibiotic residues. Copyright © 2017 Elsevier B.V. All rights reserved.

Evaluation of antimony microparticles supported on biochar for application in the voltammetric determination of paraquat.

PubMed

Gevaerd, Ava; de Oliveira, Paulo R; Mangrich, Antonio S; Bergamini, Márcio F; Marcolino-Junior, Luiz H

2016-05-01

This work describes the construction and application of carbon paste electrodes modified with biochar and antimony microparticles (SbBCPE) for voltammetric determination of paraquat using a simple and sensitive procedure based on voltammetric stripping analysis. Some parameters such as amount of biochar and antimony used in the composition of the carbon paste and instrumental parameters were examined in detail. Under optimized conditions, an analytical curve was obtained for paraquat determination employing SbBCPE, which showed a linear response ranging from 0.2 to 2.9 μmol L(-1), with limit of detection and quantification of 34 nmol L(-1) and 113 nmol L(-1), respectively, after paraquat pre-concentration of 120 s. The repeatability study presented a RSD=2.0% for 10 consecutive measurements using the same electrode surface and the reproducibility study showed a RSD=2.7% for measurements with 10 different electrode surfaces. The proposed sensor was successfully applied for paraquat determination in tap water and citric fruit juice spiked samples and good recoveries were obtained without any sample pre-treatment, showing its promising analytical performance. Copyright © 2016 Elsevier B.V. All rights reserved.

Effect of Freeze-Thaw Cycles on Grain Size of Biochar

NASA Astrophysics Data System (ADS)

Dugan, B.; Liu, Z.; Masiello, C. A.; Gonnermann, H. M.; Nittrouer, J. A.

2015-12-01

Biochar may improve soil performance by altering soil physical properties such as porosity, density, hydraulic conductivity, and water holding capacity. Because these physical properties of soil-biochar mixtures are associated with the grain size of the soil and the biochar, they may change if biochar particles are physically broken down in the environment. In cold regions, biochar may be fragmented into smaller particles when water in biochar's internal pores expands during freezing. This expansion may mechanically break particles. In this study we investigate if freeze-thaw cycles affect grain size of biochars produced at two temperatures (350°C and 500°C) from four types of feedstock (mesquite, pine, sewage waste, and miscanthus). Prior to freeze-thaw cycles, biochar's internal porosity increases with pyrolysis temperature and also varies with feedstock type. In our study, the highest internal porosity is 0.82±0.11 for 500 °C miscanthus biochar and the lowest internal porosity is 0.27±0.01 for 350 °C sewage waste biochar. Our biochars also have different median grain diameter (D50) and aspect ratio (AR). The largest D50 is 4836±132 μm for 350 °C miscanthus biochar and the smallest D50 is 2238±13 μm for 350°C sewage waste biochar. The highest AR is 0.85±0.01 for 500 °C sewage waste biochar and the lowest AR is 0.31±0.01 for 350 °C miscanthus biochar. After characterizing the initial properties of biochars, we saturated our biochar using synthetic rain water and subjected them to 10 freeze-thaw cycles (freeze at -19±3°C for 8 hours and thaw at 20±0°C for 16 hours). We expect that D50 will be reduced and AR will be changed by freeze-thaw cycles and the effect will vary with biochar porosity. Ultimately this work will help constrain how biochar particle size changes due to freezing, which can be extrapolated to understand transients in soil performance associated with biochar particle size.

Attenuation of phenanthrene and pyrene adsorption by sewage sludge-derived biochar in biochar-amended soils.

PubMed

Zielińska, Anna; Oleszczuk, Patryk

2016-11-01

The aim of this study was to evaluate the effect of soils on the sorption of phenanthrene (PHE) and pyrene (PYR) by sewage sludge-derived biochars (SS-derived biochars). The SS-derived biochars were added to soils with varying properties as well as with a different degree and source of polycyclic aromatic hydrocarbons (PAHs) contamination. The biochars (BCs) were produced from sewage sludge during pyrolysis at temperatures of 500 °C (BC500) and 700 °C (BC700). The addition of biochars to the soils (5 %, w/w) increased the sorption of PHE from 8.3 to 20.3 % and PYR from 14.5 to 31.7 % by amended soil. BC700 biochar was characterized by better sorption capacity than BC500 biochar. Nevertheless, the presence of soil reduces the effectiveness of biochars in binding the compounds studied. The sorption capacity of the biochars decreased several times after they had been mixed with the soil compared to pure biochars. The study found dissolved organic carbon (DOC) and clay minerals present in the soils to have a significant effect on reducing the efficiency of PHE and PYR sorption by biochar. A greater impact of fouling was observed in the case of BC500 biochar characterized by lower porosity than BC700 biochar.

Adsorption of heavy metals from aqueous solution by UV-mutant Bacillus subtilis loaded on biochars derived from different stock materials.

PubMed

Wang, Ting; Sun, Hongwen; Ren, Xinhao; Li, Bing; Mao, Hongjun

2018-02-01

Two kinds of biochars, one derived from corn straw (CBC) and one from pig manure (PBC), were used as the carriers of a bacterium (B38) to adsorb heavy metals in solution. CBC exhibited high affinity to Hg(II), while PBC showed large adsorption capacity of Pb(II). After loading with B38, the sorption capacity of the co-sorbents were enhanced for Pb(II), but weakened for Hg(II). In a binary system, the overall adsorption capacity to Hg-Pb (CBC+B38, 136.7mg/g; PBC+B38, 181.3mg/g) on co-sorbents was equal to the sum of the single-component values for Hg(II) and Pb(II). Electrostatic interactions and precipitation are the major mechanisms in the adsorption of Hg(II). In contrast, cation-π interactions and precipitation were involved in the sorption process of Pb(II). Moreover, the sorption sites of Hg(II) and Pb(II) partially overlapped on the biochar surface, but were different on co-sorbents. Hence, the co-sorbents have an advantage over the biochar alone in the removal of heavy metal mixtures. Copyright © 2017 Elsevier Inc. All rights reserved.

Fast and efficient adsorption of methylene green 5 on activated carbon prepared from new chemical activation method.

PubMed

Tran, Hai Nguyen; You, Sheng-Jie; Chao, Huan-Ping

2017-03-01

Activated carbon (AC) was synthesized from golden shower (GS) through a new chemical activation process. The three-stage process comprised (1) hydrothermal carbonization of GS to produce hydrochar, (2) pyrolysis of hydrochar to produce biochar, and (3) subsequent chemical activation of biochar with K 2 CO 3 to obtain GSHBAC. The traditional synthesis processes (i.e., one-stage and two-stage) were also examined for comparison. In the one-stage process, GS that was impregnated with K 2 CO 3 was directly pyrolyzed (GSAC), and the two-stage process consisted of (1) pyrolytic or hydrothermal carbonization to produce biochar or hydrochar and (2) subsequent chemical activation was defined as GSBAC and GSHAC, respectively. The synthesized ACs were characterized by scanning electron microscope, Brunauer-Emmett-Teller (BET) surface area analysis, Fourier transform infrared spectrometry, point zero charge, and Boehm titration. The adsorption results demonstrated that the MG5 adsorption process was not remarkably affected by neither the solution pH (2.0-10) nor ionic strength (0-0.5 M NaCl). Kinetic studies showed that the adsorption equilibrium was quickly established, with a low activation energy required for adsorption (Ea; 3.30-27.8 kJ/mol), and the ACs removed 50-73% of the MG5 concentration from solution within 01 min. Desorption studies confirmed the adsorption was irreversible. Thermodynamic experiments suggested that the MG5 adsorption was spontaneous (-ΔG°) and endothermic (+ΔH°), and increased the randomness (+ΔS°) in the system. Although the specific surface areas of the ACs followed the order GSAC (1,413) > GSHAC (1,238) > GSHBAC (903) > GSBAC (812 m 2 /g), the maximum adsorption capacities determined from the Langmuir model (Q o max ) at 30 °C exhibited the following order: GSHBAC (531) > GSAC (344) > GSHAC (332) > GSBAC (253 mg/g). Oxygenation of the ACs' surface through a hydrothermal process with acrylic acid resulted in a decrease in MG5 adsorption and identified the importance of π-π interactions to the adsorption process. The primary interactions in MG5 adsorption were π-π interactions and pore filling, while hydrogen bonding and n-π interactions were minor contributors. The three-stage process can be regarded as the effective preparation method of AC with a high adsorption capacity toward the cationic dye. Copyright © 2016 Elsevier Ltd. All rights reserved.

Biochar particle size, shape, and porosity act together to influence soil water properties.

PubMed

Liu, Zuolin; Dugan, Brandon; Masiello, Caroline A; Gonnermann, Helge M

2017-01-01

Many studies report that, under some circumstances, amending soil with biochar can improve field capacity and plant-available water. However, little is known about the mechanisms that control these improvements, making it challenging to predict when biochar will improve soil water properties. To develop a conceptual model explaining biochar's effects on soil hydrologic processes, we conducted a series of well constrained laboratory experiments using a sand matrix to test the effects of biochar particle size and porosity on soil water retention curves. We showed that biochar particle size affects soil water storage through changing pore space between particles (interpores) and by adding pores that are part of the biochar (intrapores). We used these experimental results to better understand how biochar intrapores and biochar particle shape control the observed changes in water retention when capillary pressure is the main component of soil water potential. We propose that biochar's intrapores increase water content of biochar-sand mixtures when soils are drier. When biochar-sand mixtures are wetter, biochar particles' elongated shape disrupts the packing of grains in the sandy matrix, increasing the volume between grains (interpores) available for water storage. These results imply that biochars with a high intraporosity and irregular shapes will most effectively increase water storage in coarse soils.

Influence of biochar and terra preta substrates on wettability and erodibility of soils

NASA Astrophysics Data System (ADS)

Smetanova, A.; Dotterweich, M.; Diehl, D.; Ulrich, U.; Fohrer, N.

2012-04-01

Biochar (BC) and terra preta substrates (TPS) have recently been promoted as soil amendments suitable for soil stabilization, soil amelioration and long-term carbon sequestration. BC is a carbon-enriched substance produced by thermal decomposition of organic material. TPS is composed of liquid and solid organic matter, including BC, altered by acid-lactic fermentation. Their effect on wettability, soil erodibility and nutrient discharge through overland flow was studied by laboratory experiments. At water contents between 0 and 100% BC is water repellent, while TPS changes from a wettable into a repellent state. The 5 and 10 vol % mixtures of BC and 10 and 20 vol% mixtures of TPS with sand remain mainly wettable during drying but repellency maxima are shifted to higher water contents with respect to pure sand and are mainly of subcritical nature. The runoff response was dominated by infiltration properties of the substrates rather than their wettability.Only one mixtures (20% TPS) produced more runoff than sandy-loamy soil on a 15% slope at an intensity of 25 mm•h-1. The 10% BC decreased runoff by up to 40%. At higher rainfall intensities (45 and 55 mm•h-1) the 10% TPS7 was up to 35% less erodible than 10% BC. Despite the TPS containing more nutrients, nutrient discharge varied between types of nutrients, slopes, rainfall intensities and mixtures. The application of a 1 cm layer onto the soil surface instead of 10% mixtures is not recommended due to high nutrient concentrations in the runoff and the wettability of pure substrates. The usage of 10% BC in lowland areas with low frequency and low-intensity precipitation and 10% TPS7 in areas with higher rainfall intensities appears to be appropriate and commendable according to current results. However, together with reversibility of repellency, it needs to undergo further examination in the field under different environmental and land use conditions Key words: biochar, terra preta substrate, wettability, erodibility, nutrient discharge

Agronomic value of sewage sludge and corn cob biochar in an infertile Oxisol

NASA Astrophysics Data System (ADS)

Deenik, J. L.; Cooney, M. J.; Antal, M. J., Jr.

2013-12-01

Disposal of sewage sludge and other agricultural waste materials has become increasingly difficult in urban environments with limited land space. Carbonization of the hazardous waste produces biochar as a soil amendment with potential to improve soil quality and productivity. A series of greenhouse pot experiments were conducted to assess the agrnomic value of two biochars made from domestic wastewater sludge and corn cob waste. The ash component of the sewage sludge biochar was very high (65.5%) and high for the corn cob (11.4%) biochars. Both biochars contained low concentrations of heavy metals and met EPA land application criteria. The sewage sludge biochar was a better liming material and source of mineral nutrients than the corn cob biochar, but the corn cob biochar showed the greatest increase in soil carbon and total nitrogen. Both biochar materials increased soil pH compared with soils not receiving biochar, but the sewage sludge biochar was a more effective liming material maintaining elevated soil pH throughout the 3 planting cycles. The sewage sludge biochar also showed the greatest increase in extractable soil P and base cations. In the first planting cycle, both biochars in combination with conventional fertilizers produced significantly higher corn seedling growth than the fertilized control. However, the sewage sludge biochar maintained beneficial effects corn seedling growth through the third planting cycle showing 3-fold increases in biomass production compared with the control in the third planting. The high ash content and associated liming properties and mineral nutrient contributions in the sewage sludge biochar explain benefits to plant growth. Conversion of sewage sludge waste into biochar has the potential to effectively address several environmental issues: 1) convert a hazardous waste into a valuable soil amendment, 2) reduce land and water contamination, and 3) improve soil quality and productivity.

Organic Biochar Based Fertilization

NASA Astrophysics Data System (ADS)

Schmidt, Hans-Peter; Pandit, Bishnu Hari; Cornelissen, Gerard; Kammann, Claudia

2017-04-01

Biochar produced in cost-efficient flame curtain kilns (Kon-Tiki) was nutrient enriched either with cow urine or with dissolved mineral (NPK) fertilizer to produce biochar-based fertilizers containing between 60-100 kg N, 5-60 kg P2O5 and 60-100 kg K2O, respectively, per ton of biochar. In 21 field trials nutrient-enriched biochars were applied at rates of 0.5 to 2 t ha-1 into the root zone of 13 different annual and perennial crops. Treatments combining biochar, compost and organic or chemical fertilizer were evaluated; control treatments contained the same amounts of nutrients but without biochar. All nutrient-enriched biochar substrates improved yields compared to their respective no-biochar controls. Biochar enriched with dissolved NPK produced on average 20% ± 5.1% (N=4) higher yields than standard NPK fertilization without biochar. Cow urine-enriched biochar blended with compost resulted on average in 123% ± 76.7% (N=13) higher yields compared to the organic farmer practice with cow urine-blended compost and outcompeted NPK-enriched biochar (same nutrient dose) by 103% ± 12.4% (N=4) on average. 21 field trials robustly revealed that low-dosage root zone application of organic biochar-based fertilizers caused substantial yield increases in rather fertile silt loam soils compared to traditional organic fertilization and to mineral NPK- or NPK-biochar fertilization. This can likely be explained by the nutrient carrier effect of biochar causing a slow nutrient release behavior, more balanced nutrient fluxes and reduced nutrient losses especially when liquid organic nutrients are used for the biochar enrichment. The results promise new pathways for optimizing organic farming and improving on-farm nutrient cycling.

Effects of biochar on enhanced nutrient use efficiency of green bean, Vigna radiata L.

PubMed

Prapagdee, Songkrit; Tawinteung, Nukoon

2017-04-01

Biochar is the carbonized material produced from biomass and is used in several environmental applications. The biochar characteristics depend on the carbonization conditions and feedstock. The suitability of a given biochar for soil improvement depends on the biochar characteristics, soil properties, and target plants. Biochar has been applied at 1-20% (w/w) in the soil, but currently there is a lack of information on what type and concentration of biochar are most suitable for a specific plant and soil quality. Too much biochar will reduce plant growth because of the high alkalinity of biochar, which will cause long-term soil alkalinity. In contrast, too little biochar might be insufficient to enhance plant productivity. In this study, a suitable concentration of cassava stem (an abundant agricultural waste in Thailand) biochar produced at 350 °C was evaluated for green bean (Vigna radiata L.) growth from germination to seed production in pots over 8 weeks. The soil fertility was increased with increasing biochar concentration. At 5% (w/w) biochar, the soil fertility and plant growth were significantly enhanced, while 10% (w/w) biochar significantly enhanced bean growth and bean pod production. The increased biochar concentration in the soil significantly increased the soil total nitrogen and extractable potassium (K) levels but did not affect the amount of available phosphorous. Biochar at 10% (w/w) significantly induced the accumulation of K in the stems, leaves, nut shells, and roots but not in nut seeds. Moreover, biochar not only increased the K concentration in soil but also increased the plant nutrient use efficiency of K, which is important for plant growth. Graphical abstract ᅟ.

Sorption of atrazine, acetochlor, and 2,4-D by hardwood-derived biochar

NASA Astrophysics Data System (ADS)

Gonzalez, J. M.; Shipitalo, M. J.

2016-12-01

Offsite transport of herbicides and other agricultural pesticides to streams and other bodies of water can adversely impact drinking water supplies and aquatic ecology. Atrazine, acetochlor, and 2,4-D are herbicides commonly used to control weeds in maize (Zea mays) and soybean (Glycine max), the dominant crops in the U.S. Midwest. Unfortunately, these materials are frequently detected at high concentrations in surface runoff and subsurface drainage, especially when rainstorms occur shortly after their application. Thus, edge-of-field technologies employing effective sorbents to remove pesticides in water are needed to reduce this concern. In this study, we investigated the sorption of atrazine, acetochlor, and 2,4-D by a hardwood-derived biochar. Sorption kinetics and isotherms were determined for each pesticide using concentrations ranging from 5 to 100 ug L-1. The results from the kinetic sorption studies were fitted to pseudo first- and second-order reaction models and demonstrated that sorption was fast; in less than an hour > 90% of the added pesticides were sorbed and after 24 hours up to 100% was removed. The pH of the suspensions after the sorption kinetic and isotherm studies was 8.26 ± 0.51. Thus, because of the nature of the biochar and the pesticides used in this study, hydrophobic interactions appear to be the main mechanism of sorption. Furthermore, since the sorption was fast, we hypothesize that sorption occurred on the surface of biochar. The information from this study can be used to develop agricultural best management practices to remove pesticides in water.

Effects of amendment of different biochars on soil physical and biological properties related to carbon mineralization

NASA Astrophysics Data System (ADS)

Zhang, Renduo; Zhu, Shuzhi; Ouyang, Lei

2014-05-01

Biochar addition to soils potentially affects various soil properties, and these effects are dependent on biochars derived from different feedstock materials and pyrolysis processes. The objective of this study was to investigate the effects of amendment of different biochars on soil physical and biological properties. Biochars were produced with dairy manure and woodchip at temperatures of 300, 500, and 700°C, respectively. Each biochar was mixed at 5% (w/w) with a forest soil and the mixture was incubated for 180 days, during which soil physical and biological properties, and soil respiration rates were measured. Results showed that the biochar addition significantly enhanced the formation of soil macroaggregates at the early incubation time. The biochar application significantly reduced soil bulk density, increased the amount of soil organic matter, and stimulated microbial activity and soil respiration rates at the early incubation stage. Biochar applications improved water retention capacity, with stronger effects by biochars produced at higher pyrolysis temperatures. At the same suction, the soil with woodchip biochars possessed higher water content than with the dairy manure biochars. Biochar addition significantly affected the soil physical and biological properties, which resulted in different soil carbon mineralization rates.

Effect of low dosage biochar amendment on plant physiology parameters of sunflowers

NASA Astrophysics Data System (ADS)

María De la Rosa, José; Paneque, Marina; Franco-Navarro, Juan D.; Colmenero-Flores, José Manuel; Knicker, Heike

2017-04-01

Four different biochars were used as organic ameliorants in a typical agricultural soil of the Mediterranean region a (Calcic Cambisol). This field study was performed with plants of sunflower (Helianthus annuus L.) at the experimental station "La Hampa", located in the Guadalquivir river valley (SW Spain). The soil was amended with doses equivalent to 1.5 and 15 t ha-1 of the four biochars in two independent plantations. In addition, un-amended plots were prepared for comparison purposes 1. This study showed that the amendment with 1.5 t biochar ha-1 did not modify significantly soil properties, or the agronomic productivity of sunflowers. However, in spite of this low dose of biochar, positive effects on plant physiology were observed. The efficiency of Photosystem-II (quantum yield (QYPSII)), is a stress marker, related to the water status of the plant, and is reduced under drought stress. The QYPSII values of the plants grown with 1.5 t biochar ha-1 were higher than in the control and ranged between 72 and 77%. Values between 70 and 80% correspond to non-stressed (well-watered) sunflower plants. Biochar reduced stomatal conductance (gs, leaf transpiration) in both treatments. Therefore, the dependence of agronomic productivity on biochar dose was not observed, since both doses resulted in similar gs reductions. In C3 plants, such as sunflower, an increase of leaf area (LA) is usually associated to a decrease of gs caused by a reduction of stomatal frequency and increases the water use efficiency and drought tolerance 2. However, here no clear correlation could be established between biochar-induced LA stimulation and gs response after application of biochar. Thus, gs reduction was evident but not a consequence of LA increase. We hypothesize that biochar addition to soils alters anatomical and/or physiological parameters of the plants that in turn reduces stomatal conductance and increases water use efficiency of sunflower plants. After the last rain, increasing drought and water deficit resulted in a progressive reduction of gs in control plants. The more efficient use of water increased drought tolerance of amended plants. Therefore, we propose that biochar amendment provides protection from water deficit stress, a finding that points to the agronomic relevance of biochar use for Mediterranean rainfed crops. Acknowledgements: J.M. de la Rosa and Marina Paneque thank the Spanish Ministry of Economy and Competitiveness (MINECO) for his "Ramón y Cajal" post-doctoral contract and her FPU fellowship (FPU 13/05831) respectively. MINECO, the European Regional Development Fund and Marie Curie Integration Grants of 7th European Community Framework Programme are thanked for the financial support (CGL2015-64811-P, PCIG12-GA-2012-333784). References: 1Paneque M., De la Rosa J.M., Franco-Navarro J., Colmenero-Flores JM., Knicker H., 2016. CATENA. 147, 280-287. 2 Franco-Navarro J.D., Brumós J., Rosales M.A., Cubero-Font P., Talón M., Colmenero-Flores J.M., 2016. J. Exp. Bot. 67, 873-891.

High-VOC biochar-effectiveness of post-treatment measures and potential health risks related to handling and storage.

PubMed

Buss, Wolfram; Mašek, Ondřej

2016-10-01

Biochar can contain volatile organic compounds (VOCs), formed and introduced during the pyrolysis process. In some pyrolysis units or under specific conditions during production, pyrolysis vapours can deposit on biochar in significant amounts resulting in high-VOC biochar. In this study, it was tested to which extent VOCs are released from such high-VOC biochars when openly stored, which post-treatment measures are most effective in reducing phytotoxic potential and whether the VOC emissions could exceed human health-related threshold values. It was shown that the initial VOC release of high-VOC biochars can exceed occupational exposure limit values and even after 2 months, the biochars still emitted VOCs exceeding air quality guideline values. Consequently, these specific high-VOC biochars pose health risks when handled or stored openly. Simple open-air storage turned out to be insufficient for VOC removal. Low temperature treatment, on the other hand, removed VOCs from the high-VOC biochars effectively and alleviated any human health risks and phytotoxic effects. In addition to the high-VOC biochars, a low-VOC biochar was tested which did not emit any VOCs and was even able to sorb VOCs from the VOC-rich biochar to a certain extent. Thermal treatment and blending with low-VOC biochar are methods which could be used in practise to treat high-VOC biochar, reducing VOC emissions. This study revealed significant new findings on the topic of VOCs in biochar which highlights the need to include VOCs in the list of priority contaminants in biochar.

Characterization and quantification of biochar alkalinity.

PubMed

Fidel, Rivka B; Laird, David A; Thompson, Michael L; Lawrinenko, Michael

2017-01-01

Lack of knowledge regarding the nature of biochar alkalis has hindered understanding of pH-sensitive biochar-soil interactions. Here we investigate the nature of biochar alkalinity and present a cohesive suite of methods for its quantification. Biochars produced from cellulose, corn stover and wood feedstocks had significant low-pK a organic structural (0.03-0.34 meq g -1 ), other organic (0-0.92 meq g -1 ), carbonate (0.02-1.5 meq g -1 ), and other inorganic (0-0.26 meq g -1 ) alkalinities. All four categories of biochar alkalinity contributed to total biochar alkalinity and are therefore relevant to pH-sensitive soil processes. Total biochar alkalinity was strongly correlated with base cation concentration, but biochar alkalinity was not a simple function of elemental composition, soluble ash, fixed carbon, or volatile matter content. More research is needed to characterize soluble biochar alkalis other than carbonates and to establish predictive relationships among biochar production parameters and the composition of biochar alkalis. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of biochar particle size on hydrophobic organic compound sorption kinetics: Applicability of using representative size.

PubMed

Kang, Seju; Jung, Jihyeun; Choe, Jong Kwon; Ok, Yong Sik; Choi, Yongju

2018-04-01

Particle size of biochar may strongly affect the kinetics of hydrophobic organic compound (HOC) sorption. However, challenges exist in characterizing the effect of biochar particle size on the sorption kinetics because of the wide size range of biochar. The present study suggests a novel method to determine a representative value that can be used to show the dependence of HOC sorption kinetics to biochar particle size on the basis of an intra-particle diffusion model. Biochars derived from three different feedstocks are ground and sieved to obtain three daughter products each having different size distributions. Phenanthrene sorption kinetics to the biochars are well described by the intra-particle diffusion model with significantly greater sorption rates observed for finer grained biochars. The time to reach 95% of equilibrium for phenanthrene sorption to biochar is reduced from 4.6-17.9days for the original biochars to <1-4.6days for the powdered biochars with <125μm in size. A moderate linear correlation is found between the inverse square of the representative biochar particle radius obtained using particle size distribution analysis and the apparent phenanthrene sorption rates determined by the sorption kinetics experiments and normalized to account for the variation of the sorption rate-determining factors other than the biochar particle radius. The results suggest that the representative biochar particle radius reasonably describes the dependence of HOC sorption rates on biochar particle size. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of Biochar-Derived Sewage Sludge on Heavy Metal Adsorption and Immobilization in Soils

PubMed Central

Zhou, Dan; Liu, Dan; Gao, Fengxiang; Li, Mengke; Luo, Xianping

2017-01-01

The object of this study was to evaluate the effect of sewage sludge biochar on adsorption and mobility of Cr, Mn, Cu, and Zn. Biochar (BC400) was produced via pyrolysis of municipal sewage sludge at 400 °C. Maximum adsorption capacities (qm) for Zn, Cr, Mn, and Cu were 5.905, 5.724, 5.681, and 5.342 mg·g−1, respectively, in the mono-metal solution and 2.475, 8.204, 1.01, and 5.415 mg·g−1, respectively, in the multi-metal solution. The adsorption capacities for Mn, Cu, and Zn decreased in the multi-metal solution due to competitive adsorption, whereas the capacity for Cr increased. Surface precipitation is an important mechanism in the sorption of these metals on BC400. The 360-day incubation experiment showed that BC400 application reduced metal mobility in contaminated soils, which was attributed to the substantial decreases in the acid-soluble fractions of Cr, Mn, Cu, and Zn (72.20%, 70.38%, 50.43%, and 29.78%, respectively). Furthermore, the leaching experiment using simulated acid rain indicated that the addition of BC400 enhanced the acid buffer capacity of contaminated soil, and the concentration of Cr, Mn, Cu, and Zn in the leachate was lower than in untreated soil. Overall, this study indicates that sewage sludge biochar application reduces the mobility of heavy metal in co-contaminated soil, and this adsorption experiment is suitable for the evaluation of biochar properties for remediation. PMID:28644399

Effects of Biochar-Derived Sewage Sludge on Heavy Metal Adsorption and Immobilization in Soils.

PubMed

Zhou, Dan; Liu, Dan; Gao, Fengxiang; Li, Mengke; Luo, Xianping

2017-06-23

The object of this study was to evaluate the effect of sewage sludge biochar on adsorption and mobility of Cr, Mn, Cu, and Zn. Biochar (BC400) was produced via pyrolysis of municipal sewage sludge at 400 °C. Maximum adsorption capacities ( q m ) for Zn, Cr, Mn, and Cu were 5.905, 5.724, 5.681, and 5.342 mg·g -1 , respectively, in the mono-metal solution and 2.475, 8.204, 1.01, and 5.415 mg·g -1 , respectively, in the multi-metal solution. The adsorption capacities for Mn, Cu, and Zn decreased in the multi-metal solution due to competitive adsorption, whereas the capacity for Cr increased. Surface precipitation is an important mechanism in the sorption of these metals on BC400. The 360-day incubation experiment showed that BC400 application reduced metal mobility in contaminated soils, which was attributed to the substantial decreases in the acid-soluble fractions of Cr, Mn, Cu, and Zn (72.20%, 70.38%, 50.43%, and 29.78%, respectively). Furthermore, the leaching experiment using simulated acid rain indicated that the addition of BC400 enhanced the acid buffer capacity of contaminated soil, and the concentration of Cr, Mn, Cu, and Zn in the leachate was lower than in untreated soil. Overall, this study indicates that sewage sludge biochar application reduces the mobility of heavy metal in co-contaminated soil, and this adsorption experiment is suitable for the evaluation of biochar properties for remediation.

Whole systems thinking for sustainable water treatment design

NASA Astrophysics Data System (ADS)

Huggins, Mitchell Tyler

Microbial fuel cell (MFC) technology could provide a low cost alternative to conventional aerated wastewater treatment, however there has been little comparison between MFC and aeration treatment using real wastewater substrate. This study attempts to directly compare the wastewater treatment efficiency and energy consumption and generation among three reactor systems, a traditional aeration process, a simple submerged MFC configuration, and a control reactor acting similar as natural lagoons. Results showed that all three systems were able to remove >90% of COD, but the aeration used shorter time (8 days) then the MFC (10 days) and control reactor (25 days). Compared to aeration, the MFC showed lower removal efficiency in high COD concentration but much higher efficiency when the COD is low. Only the aeration system showed complete nitrification during the operation, reflected by completed ammonia removal and nitrate accumulation. Suspended solid measurements showed that MFC reduced sludge production by 52-82% as compared to aeration, and it also saved 100% of aeration energy. Furthermore, though not designed for high power generation, the MFC reactor showed a 0.3 Wh/g COD/L or 24 Wh/m3 (wastewater treated) net energy gain in electricity generation. These results demonstrate that MFC technology could be integrated into wastewater infrastructure to meet effluent quality and save operational cost. The high cost and life-cycle impact of electrode materials is one major barrier to the large scale application of microbial fuel cells (MFC). We also demonstrate that biomass-derived black carbon (biochar), could be a more cost effective and sustainable alternative to granular activated carbon (GAC) and graphite granule (GG) electrodes. In a comparison study, two biochar materials made from lodgepole pine sawdust pellets (BCp) and lodgepole pine woodchips (BCc), gassified at a highest heat temperature (HHT) of 1000°C under a heating rate of 16°C/min, showed a satisfactory power density of 532 +/- 18 mW/m-2 and 457 +/- 20 mW/m-2 respectively, compared to GAC with 674 +/- 10 mW/m-2 and GG with 566 +/- 5 mW/m-2 (normalized to cathode projected surface area), as an anode material in a two-chamber MFC. BCc and BCp had BET-N2 surface area measurements of 429 cm2 g -1 and 470 cm2 g-1 respectively, lower than industrial GAC with 1248 cm2 g-1 but several orders of magnitude higher that GG with 0.44 cm2 g-1 . BCc and BCp had a lower surface resistance of 3+/-1Ω mm -1 and 6+/-1 Ω mm-1 than 8+/-2Ω mm -1 for GAC, but higher that GG with 0.4+/-0.5 Ω mm -1. We also investigated the life-cycle impact and estimated cost of biochar as an electrode material. Although there is no well-established market price for biochar, conservative estimates place the costs around 51-356 US/tonne, up to ten times cheaper that GAC (500-2500 US/tonne) and GGs (500-800 US$/tonne) with significantly greater life-cycle advantages.

Good for sewage treatment and good for agriculture: Algal based compost and biochar.

PubMed

Cole, Andrew J; Paul, Nicholas A; de Nys, Rocky; Roberts, David A

2017-09-15

In this study we test a novel approach to closing the anthropogenic nutrient cycle, by using the freshwater macroalga, Oedogonium intermedium, to recover dissolved nitrogen (N) and phosphorous (P) from municipal wastewater. We then convert this cultivated algae into two types of soil ameliorant; compost and biochar. To produce compost, algae was combined with sugarcane bagasse and left to mature for 10 weeks, and to produce biochar, algae was processed through slow pyrolysis at 450 °C. The mature compost had a total N and P content of 2.5% and 0.6%, which was 2- to 4-times lower than the algal biochar, which had a total N and P content of 5.5% and 2.5% respectively. Composting stabilized the N and P recovered from wastewater, with 80% of the initial N and >99% of the initial P retained in the mature compost. In contrast, only 29% of the initial N and 62% of the initial P was retained in the biochar. When the mature compost was added to a low fertility soil it significantly increased the production of sweet corn (Zea mays). Treatments receiving 50 and 100% compost produced 4-9 times more corn biomass than when synthetic fertilizer alone was added to the low fertility soil. When biochar was applied in conjunction with compost there was an additional 15% increase in corn productivity, most likely due to the ability of the biochar to bind labile N and P and prevent its loss from the soil. This study demonstrates a unique model for recovering N and P from municipal wastewater and recycling these nutrients into the agricultural industry. This could be an ideal model for regional areas where agriculture and water treatment facilities are co-located and could ultimately reduce the reliance of agriculture on finite mineral sources of P. Copyright © 2017 Elsevier Ltd. All rights reserved.

Application of the 15N tracer method to study the effect of pyrolysis temperature and atmosphere on the distribution of biochar nitrogen in the biomass-biochar-plant system.

PubMed

Tan, Zhongxin; Ye, Zhixiong; Zhang, Limei; Huang, Qiaoyun

2018-05-01

Biochar nitrogen is key to improving soil fertility, but the distribution of biochar nitrogen in the biomass-biochar-plant system is still unclear. To provide clarity, the 15 N tracer method was utilised to study the distribution of biochar nitrogen in the biochar both before and after its addition to the soil. The results can be summarised as follows. 1) The retention rate of 15 N in biochar decreases from 45.23% to 20.09% with increasing pyrolysis temperature from 400 to 800°C in a CO 2 atmosphere. 2) The retention rate of 15 N in biochar prepared in a CO 2 atmosphere is higher than that prepared in a N 2 atmosphere when the pyrolysis temperature is below 600°C. 3) Not only can biochar N slowly facilitate the adsorption of N by plants but the addition of biochar to the soil can also promote the supply of soil nitrogen to the plant; in contrast, the direct return of wheat straw biomass to the soil inhibits the absorption of soil N by plants. 4) In addition, the distribution of nitrogen was clarified; that is, when biochar was prepared by the pyrolysis of wheat straw at 400°C in a CO 2 atmosphere, the biochar retained 45.23% N, and after the addition of this biochar to the soil, 39.99% of N was conserved in the biochar residue, 4.55% was released into the soil, and 0.69% was contained in the wheat after growth for 31days. Therefore, this study very clearly shows the distribution of nitrogen in the biomass-biochar-plant system. Copyright © 2017 Elsevier B.V. All rights reserved.

Influence of biochar aged in acidic soil on ecosystem engineers and two tropical agricultural plants.

PubMed

Anyanwu, Ihuoma N; Alo, Moses N; Onyekwere, Amos M; Crosse, John D; Nworie, Okoro; Chamba, Emmanuel B

2018-05-30

Biochar amendment to soil is predicted globally as a means to enhance soil health. Alongside the beneficial result on soil nutrient availability and retention, biochar is presumed to increase soil macro / microbiota composition and improve plant growth. However, evidence for such an effect remains elusive in many tropical agricultural soils. The influence of biochar aged in soil was assessed on soil microbiota, macrobiota (Eudrilus eugeniae), seedling emergence and early plant growth of Oryza sativa and Solanum lycopersicum in tropical agricultural soil, over a 90 d biochar-soil contact time. Results showed negative impacts of increased loading of biochar on the survival and growth of E. eugeniae. LC 50 and EC 50 values ranged from 34.8% to 86.8% and 0.9-23.7% dry biochar kg -1 soil, over time. The growth of the exposed earthworms was strongly reduced (R 2 = -0.866, p < 0.05). Biochar significantly increased microbiota abundance relative to the control soil (p < 0.001). However, fungal population was reduced by biochar addition. Biochar application threshold of 10% and 5% was observed for (O. sativa) and (S. lycopersicum), respectively. Furthermore, the addition of biochar to soil resulted in increased aboveground (shoot) biomass (p < 0.01). However, the data revealed that biochar did not increase the belowground (root) biomass of the plant species during the 90 d biochar-soil contact time. The shoot-to-root-biomass increase indicates a direct toxic influence of biochar on plant roots. This reveals that nutrient availability is not the only mechanism involved in biota-biochar interactions. Detailed studies on specific biota-plant-responses to biochars between tropical, temperate and boreal environments are needed to resolve the large variations and mechanisms behind these effects. Copyright © 2018 Elsevier Inc. All rights reserved.

Sorption of Pharmaceuticals, Heavy Metals, and Herbicides to Biochar in the Presence of Biosolids.

PubMed

Bair, Daniel A; Mukome, Fungai N D; Popova, Inna E; Ogunyoku, Temitope A; Jefferson, Allie; Wang, Daoyuan; Hafner, Sarah C; Young, Thomas M; Parikh, Sanjai J

2016-11-01

Agricultural practices are increasingly incorporating recycled waste materials, such as biosolids, to provide plant nutrients and enhance soil functions. Although biosolids provide benefits to soil, municipal wastewater treatment plants receive pharmaceuticals and heavy metals that can accumulate in biosolids, and land application of biosolids can transfer these contaminants to the soil. Environmental exposure of these contaminants may adversely affect wildlife, disrupt microbial communities, detrimentally affect human health through long-term exposure, and cause the proliferation of antibiotic-resistant bacteria. This study considers the use of biochar co-amendments as sorbents for contaminants from biosolids. The sorption of pharmaceuticals (ciprofloxacin, triclocarban, triclosan), and heavy metals (Cu, Cd, Ni, Pb) to biochars and biochar-biosolids-soil mixtures was examined. Phenylurea herbicide (monuron, diuron, linuron) sorption was also studied to determine the potential effect of biochar on soil-applied herbicides. A softwood (SW) biochar (510°C) and a walnut shell (WN) biochar (900°C) were used as contrasting biochars to highlight potential differences in biochar reactivity. Kaolinite and activated carbon served as mineral and organic controls. Greater sorption for almost all contaminants was observed with WN biochar over SW biochar. The addition of biosolids decreased sorption of herbicides to SW biochar, whereas there was no observable change with WN biochar. The WN biochar showed potential for reducing agrochemical and contaminant transport but may inhibit the efficacy of soil-applied herbicides. This study provides support for minimizing contaminant mobility from biosolids using biochar as a co-amendment and highlights the importance of tailoring biochars for specific characteristics through feedstock selection and pyrolysis-gasification conditions. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Physical and chemical properties of biochars co-composted with biowastes and incubated with a chicken litter compost.

PubMed

Khan, Naser; Clark, Ian; Sánchez-Monedero, Miguel A; Shea, Syd; Meier, Sebastian; Qi, Fangjie; Kookana, Rai S; Bolan, Nanthi

2016-01-01

Two experiments were conducted where three biochars, made from macadamia nutshell (MS), hardwood shaving (WS) and chicken litter (CL), were co-composted with chicken manure and sawdust, and also incubated with a chicken litter based commercial compost. Biochars were added at the rates of 5% and 10% in the co-composting and 10% and 20% in the incubation experiment. The rates of biochar had no consistent effect on the change in element contents of composted- or incubated-biochars. The biochar C demonstrated recalcitrance in both composting and incubation systems. Composting increased the CEC of biochars probably due to thermophilic oxidation. The increases in CEC of WS and CL were 6.5 and 2.2 times, respectively, for composting. Translocation of elements, between biochar and compost medium, occurred in both directions. In most cases, biochars gained elements under the influence of positive difference of concentrations (i.e., when compost medium had higher concentration of elements than biochar), while in some cases they lost elements despite a positive difference. Biochar lost some elements (WS: B; CL: B, Mg and S) under the influence of negative difference of concentrations. Some biochars showed strong affinity for B, C, N and S: the concentration of these elements gained by biochars surpassed the concentration in the respective composting medium. The material difference in the biochars did not have influence on N retention: all three netbag-biochars increased their N content. The cost of production of biochar-compost will be lower in co-composting than incubation, which involves two separate processes, i.e., composting and subsequent incubation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Converting Ni-loaded biochars into supercapacitors: Implication on the reuse of exhausted carbonaceous sorbents

NASA Astrophysics Data System (ADS)

Wang, Yifan; Zhang, Yue; Pei, Lei; Ying, Diwen; Xu, Xiaoyun; Zhao, Ling; Jia, Jinping; Cao, Xinde

2017-01-01

Biochar derived from waste biomass has proven as a promising sorbent for removal of heavy metals from wastewater. However, proper disposal of such a heavy metal-containing biochar is challengeable. The major objective of this study is to create a reuse way by converting the heavy metal-loaded biochar into supercapacitor. Two biochars were produced from dairy manure and sewage sludge, respectively, and subjected to sorption of Ni from solution, and then the Ni-loaded biochar underwent microwave treatments for fabrication of supercapacitor. The specific capacitance of biochar supercapacitor increased with Ni loading, especially the Ni-loaded biochar further treated with microwave in which the capacitance increased by over 2 times, compared to the original biochar supercapacitors. The increase of capacitance in the Ni-loaded biochar supercapacitor following microwave treatment was mainly attributed to the conversion of Ni into NiO and NiOOH, which was evidenced by X-ray diffraction and X-ray photoelectron spectroscopy. The biochar supercapacitors, especially microwave-treated Ni-loaded biochar supercapacitors exhibited the high stability of specific capacitance, with less than 2% loss after 1000 charge-discharge cycles. This study demonstrated that Ni-loaded biochar can be further utilized for generation of supercapacitor, providing a potential way for the reuse of exhausted carbonaceous sorbents.

[Effects of biochar application on greenhouse gas emission from paddy soil and its physical and chemical properties].

PubMed

Liu, Yu-xue; Wang, Yao-feng; Lü, Hao-hao; Chen, Yi; Tang, Xu; Wu, Chun-yan; Zhong, Zhe-ke; Yang, Sheng-mao

2013-08-01

A field experiment was conducted to investigate the effects of rice straw returning and rice straw biochar and life rubbish biochar application on the greenhouse gas (CH4, CO2 and N2O) emission from paddy soil, its physical and chemical properties, and rice grain yield. Compared with rice straw returning, applying rice straw biochar decreased the cumulative CH4 and N2O emissions from paddy soil significantly by 64.2% - 78.5% and 16.3% - 18.4%, respectively. Whether planting rice or not, the cumulative N2O emission from paddy soil under the applications of rice straw biochar and life rubbish biochar was decreased significantly, compared with that without biochar amendment. Under the condition of no rice planting, applying life rubbish biochar reduced the cumulative CO2 emission significantly by 25.3%. Rice straw biochar was superior to life rubbish biochar in improving soil pH and available potassium content. Both rice straw biochar and life rubbish biochar could increase the soil organic carbon content significantly, but had less effects on the soil bulk density, total nitrogen and available phosphorus contents, cation exchange capacity (CEC), and grain yield. It was suggested that compared with rice straw returning, straw biochar was more effective in improving rice grain yield.

Effects of Biochar Amendment on Soil Properties and Soil Carbon Sequestration

NASA Astrophysics Data System (ADS)

Zhang, R.; Zhu, S.

2015-12-01

Biochar addition to soils potentially affects various soil properties and soil carbon sequestration, and these effects are dependent on biochars derived from different feedstock materials and pyrolysis processes. The objective of this study was to investigate the effects of amendment of different biochars on soil physical and biological properties as well as soil carbon sequestration. Biochars were produced with dairy manure and woodchip at temperatures of 300, 500, and 700°C, respectively. Each biochar was mixed at 5% (w/w) with a forest soil and the mixture was incubated for 180 days, during which soil physical and biological properties, and soil respiration rates were measured. Results showed that the biochar addition significantly enhanced the formation of soil macroaggregates at the early incubation time. The biochar application significantly reduced soil bulk density, increased the amount of soil organic matter, and stimulated microbial activity and soil respiration rates at the early incubation stage. Biochar applications improved water retention capacity, with stronger effects by biochars produced at higher pyrolysis temperatures. At the same suction, the soil with woodchip biochars possessed higher water content than with the dairy manure biochars. Biochar addition significantly affected the soil physical and biological properties, which resulted in different soil carbon mineralization rates and the amount of soil carbon storage.

Converting Ni-loaded biochars into supercapacitors: Implication on the reuse of exhausted carbonaceous sorbents

PubMed Central

Wang, Yifan; Zhang, Yue; Pei, Lei; Ying, Diwen; Xu, Xiaoyun; Zhao, Ling; Jia, Jinping; Cao, Xinde

2017-01-01

Biochar derived from waste biomass has proven as a promising sorbent for removal of heavy metals from wastewater. However, proper disposal of such a heavy metal-containing biochar is challengeable. The major objective of this study is to create a reuse way by converting the heavy metal-loaded biochar into supercapacitor. Two biochars were produced from dairy manure and sewage sludge, respectively, and subjected to sorption of Ni from solution, and then the Ni-loaded biochar underwent microwave treatments for fabrication of supercapacitor. The specific capacitance of biochar supercapacitor increased with Ni loading, especially the Ni-loaded biochar further treated with microwave in which the capacitance increased by over 2 times, compared to the original biochar supercapacitors. The increase of capacitance in the Ni-loaded biochar supercapacitor following microwave treatment was mainly attributed to the conversion of Ni into NiO and NiOOH, which was evidenced by X-ray diffraction and X-ray photoelectron spectroscopy. The biochar supercapacitors, especially microwave-treated Ni-loaded biochar supercapacitors exhibited the high stability of specific capacitance, with less than 2% loss after 1000 charge-discharge cycles. This study demonstrated that Ni-loaded biochar can be further utilized for generation of supercapacitor, providing a potential way for the reuse of exhausted carbonaceous sorbents. PMID:28128297

Artificial Warming of Arctic Meadow under Pollution Stress: Experimental design

NASA Astrophysics Data System (ADS)

Moni, Christophe; Silvennoinen, Hanna; Fjelldal, Erling; Brenden, Marius; Kimball, Bruce; Rasse, Daniel

2014-05-01

Boreal and arctic terrestrial ecosystems are central to the climate change debate, notably because future warming is expected to be disproportionate as compared to world averages. Likewise, greenhouse gas (GHG) release from terrestrial ecosystems exposed to climate warming is expected to be the largest in the arctic. Artic agriculture, in the form of cultivated grasslands, is a unique and economically relevant feature of Northern Norway (e.g. Finnmark Province). In Eastern Finnmark, these agro-ecosystems are under the additional stressor of heavy metal and sulfur pollution generated by metal smelters of NW Russia. Warming and its interaction with heavy metal dynamics will influence meadow productivity, species composition and GHG emissions, as mediated by responses of soil microbial communities. Adaptation and mitigation measurements will be needed. Biochar application, which immobilizes heavy metal, is a promising adaptation method to promote positive growth response in arctic meadows exposed to a warming climate. In the MeadoWarm project we conduct an ecosystem warming experiment combined to biochar adaptation treatments in the heavy-metal polluted meadows of Eastern Finnmark. In summary, the general objective of this study is twofold: 1) to determine the response of arctic agricultural ecosystems under environmental stress to increased temperatures, both in terms of plant growth, soil organisms and GHG emissions, and 2) to determine if biochar application can serve as a positive adaptation (plant growth) and mitigation (GHG emission) strategy for these ecosystems under warming conditions. Here, we present the experimental site and the designed open-field warming facility. The selected site is an arctic meadow located at the Svanhovd Research station less than 10km west from the Russian mining city of Nikel. A splitplot design with 5 replicates for each treatment is used to test the effect of biochar amendment and a 3oC warming on the Arctic meadow. Ten circular split plots (diameter: 3.65 m & surface area: 10.5 m2) composed of one half amended with biochar and one control half not amended were prepared. Five of these plots are equipped with a warming system, while the other five were equipped with dummies. Each warmed plot is collocated with a control plot within one block. While split plots are all oriented in the same direction the position of blocks is randomized to eliminate the effect of the spatial variability. Biochar was incorporated in the first 20 cm of the soil with a rototiller. Warming system is provided by hexagonal arrays of infrared heaters. The temperature of the plots is monitored with infrared cameras. The 3oC increase of temperature is obtained by dynamically monitoring the temperature difference between warmed and control plots within blocks via improved software. Each plot is further equipped with a soil temperature and moisture sensor.

The effect of young biochar on soil respiration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Jeffery L.; Collins, Harold P.; Bailey, Vanessa L.

2010-12-01

The low temperature pyrolysis of organic material produces biochar, a charcoal like substance. Biochar is being promoted as a soil amendment to enhance soil quality, it is also seen as a mechanism of lomg-term sequestration of carbon. Our experiments tested the hypothesis that biochar is inert in soil. However, we measured an increase in CO2 production from soils after biochar amendment which increased with increasing rates of biochar. The ∂13C signature of the CO2 evolved in the first several days of the incubation was the same as the ∂13C signature of the biochar, confirming that biochar contributed to the CO2more » flux. This effect diminished by day 6 of the incubation suggesting that most of the biochar C is slowly decomposing. Thus, aside from this short term mineralization increasing soil C with biochar may indeed be a long term C storage mechanism.« less

Pyrolysis temperature influences ameliorating effects of biochars on acidic soil.

PubMed

Wan, Qing; Yuan, Jin-Hua; Xu, Ren-Kou; Li, Xing-Hui

2014-02-01

The biochars were prepared from straws of canola, corn, soybean, and peanut at different temperatures of 300, 500, and 700 °C by means of oxygen-limited pyrolysis.Amelioration effects of these biochars on an acidic Ultisol were investigated with incubation experiments, and application rate of biochars was 10 g/kg. The incorporation of these biochars induced the increase in soil pH, soil exchangeable base cations, base saturation, and cation exchange capacity and the decrease in soil exchangeable acidity and exchangeable Al. The ameliorating effects of biochars on acidic soil increased with increase in their pyrolysis temperature. The contribution of oxygen-containing functional groups on the biochars to their ameliorating effects on the acidic soil decreased with the rise in pyrolysis temperature, while the contribution from carbonates in the biochars changed oppositely. The incorporation of the biochars led to the decrease in soil reactive Al extracted by 0.5mol/L CuCl2, and the content of reactive Al was decreased with the increase in pyrolysis temperature of incorporated biochars. The biochars generated at 300 °C increased soil organically complexed Al due to ample quantity of oxygen-containing functional groups such as carboxylic and phenolic groups on the biochars, while the biochars generated at 500 and 700 °C accelerated the transformation of soil exchangeable Al to hydroxyl-Al polymers due to hydrolysis of Al at higher pH. Therefore, the crop straw-derived biochars can be used as amendments for acidic soils and the biochars generated at relatively high temperature have great ameliorating effects on the soils.

Extractable pool of biochar controls on crop productivity rather than greenhouse gas emission from a rice paddy under rice-wheat rotation.

PubMed

Korai, Punhoon Khan; Xia, Xin; Liu, Xiaoyu; Bian, Rongjun; Omondi, Morris Oduor; Nahayo, Alphonse; Pan, Genxing

2018-01-16

The role of extractable pool of biochar in crop productivity and soil greenhouse gas (GHGs) emission is not yet clear. In this study, two biochars with and without extraction was added to a paddy before rice transplantation at 20 t·ha -1 . Crop yield, plant traits and greenhouse gas emission monitored throughout a rice-wheat rotation. Between the biochar treatments, changes in bulk density and microbial biomass carbon were insignificant. However, the increase in organic carbon was similar between maize and wheat biochars while higher under bulk wheat biochar than extracted one. The increase in available P and K was higher under wheat than maize biochar regardless of extraction. Moreover, the increase in plant traits and grain yield, in rice season only, was higher under bulk than extracted biochars. Yet, there was no difference in changes in GHGs emission between bulk and extracted biochars regardless of feedstock. Nevertheless, increased methane emission for rice season was lower under extracted biochars than bulk ones. Overall, crop productivity rather than GHGs emission was affected by treatment of extraction of biochars. Thus, use of unextracted biochar is recommended for improving soil crop productivity in the paddy soils.

Biochar Addition Increases the Rates of Dissimilatory Iron Reduction and Methanogenesis in Ferrihydrite Enrichments

PubMed Central

Zhou, Guo-Wei; Yang, Xiao-Ru; Marshall, Christopher W.; Li, Hu; Zheng, Bang-Xiao; Yan, Yu; Su, Jian-Qiang; Zhu, Yong-Guan

2017-01-01

Biochar contains quinones and aromatic structures that facilitate extracellular electron transfer between microbial cells and insoluble minerals. In this study, granulated biochar (1.2–2 mm) and powdered biochar (<0.15 mm) were amended to two ferrihydrite (in situ ferrihydrite and ex situ ferrihydrite) enrichments to investigate the effect of biochar with different particle sizes on dissimilatory iron(III)-reducing bacteria (DIRB) and methanogens. Biochar addition significantly stimulated the reduction of both in situ ferrihydrite and ex situ ferrihydrite and the production of methane. Powdered biochar amendments increased iron reduction compared to granulated biochar amendment in both the in situ ferrihydrite and ex situ ferrihydrite enrichments. However, no significant difference was observed in methane production between the powdered biochar and granulated biochar amendments in the two ferrihydrite enrichments. Analysis of 16S rRNA gene sequences showed that both DIRB and methanogens were enriched after biochar amendments in the in situ ferrihydrite and ex situ ferrihydrite enrichments. Taxa belonging to the Geobacteraceae and methanogenic genus affiliated to Methanosarcina were detected with significantly higher relative abundances in powdered biochar amendments than those in granulated biochar amendments in both the ferrihydrite enrichments. X-ray diffraction analysis indicated green rust [Fe2(CO3) (OH)] and vivianite [Fe3(PO4)2 8(H2O)] formed in the ex situ ferrihydrite and in situ ferrihydrite enrichments without biochar addition, respectively. After granulated biochar amendment, the mineral phase changed from the green rust to vivianite in the ex situ ferrihydrite enrichment, while crystalline vivianite and iron oxide (γ-Fe2O3) were detected simultaneously in the in situ ferrihydrite enrichment. No crystalline iron compound was found in the powdered biochar amendments in both ferrihydrite enrichments. Overall, our study illustrated that the addition of biochar affected iron-reducing and methane-generating microbial communities to some extent. PMID:28428774

Soil and foliar nutrient and nitrogen isotope composition (δ(15)N) at 5 years after poultry litter and green waste biochar amendment in a macadamia orchard.

PubMed

Bai, Shahla Hosseini; Xu, Cheng-Yuan; Xu, Zhihong; Blumfield, Timothy J; Zhao, Haitao; Wallace, Helen; Reverchon, Frédérique; Van Zwieten, Lukas

2015-03-01

This study aimed to evaluate the improvement in soil fertility and plant nutrient use in a macadamia orchard following biochar application. The main objectives of this study were to assess the effects of poultry litter and green waste biochar applications on nitrogen (N) cycling using N isotope composition (δ(15)N) and nutrient availability in a soil-plant system at a macadamia orchard, 5 years following application. Biochar was applied at 10 t ha(-1) dry weight but concentrated within a 3-m diameter zone when trees were planted in 2007. Soil and leaf samples were collected in 2012, and both soil and foliar N isotope composition (δ(15)N) and nutrient concentrations were assessed. Both soil and foliar δ(15)N increased significantly in the poultry litter biochar plots compared to the green waste biochar and control plots. A significant relationship was observed between soil and plant δ(15)N. There was no influence of either biochars on foliar total N concentrations or soil NH4 (+)-N and NO3 (-)-N, which suggested that biochar application did not pose any restriction for plant N uptake. Plant bioavailable phosphorus (P) was significantly higher in the poultry litter biochar treatment compared to the green waste biochar treatment and control. We hypothesised that the bioavailability of N and P content of poultry litter biochar may play an important role in increasing soil and plant δ(15)N and P concentrations. Biochar application affected soil-plant N cycling and there is potential to use soil and plant δ(15)N to investigate N cycling in a soil-biochar-tree crop system. The poultry litter biochar significantly increased soil fertility compared to the green waste biochar at 5 years following biochar application which makes the poultry litter a better feedstock to produce biochar compared to green waste for the tree crops.

Nitrate capture and slow release in biochar amended compost and soil.

PubMed

Hagemann, Nikolas; Kammann, Claudia I; Schmidt, Hans-Peter; Kappler, Andreas; Behrens, Sebastian

2017-01-01

Slow release of nitrate by charred organic matter used as a soil amendment (i.e. biochar) was recently suggested as potential mechanism of nutrient delivery to plants which may explain some agronomic benefits of biochar. So far, isolated soil-aged and composted biochar particles were shown to release considerable amounts of nitrate only in extended (>1 h) extractions ("slow release"). In this study, we quantified nitrate and ammonium release by biochar-amended soil and compost during up to 167 h of repeated extractions in up to six consecutive steps to determine the effect of biochar on the overall mineral nitrogen retention. We used composts produced from mixed manures amended with three contrasting biochars prior to aerobic composting and a loamy soil that was amended with biochar three years prior to analysis and compared both to non-biochar amended controls. Composts were extracted with 2 M KCl at 22°C and 65°C, after sterilization, after treatment with H2O2, after removing biochar particles or without any modification. Soils were extracted with 2 M KCl at 22°C. Ammonium was continuously released during the extractions, independent of biochar amendment and is probably the result of abiotic ammonification. For the pure compost, nitrate extraction was complete after 1 h, while from biochar-amended composts, up to 30% of total nitrate extracted was only released during subsequent extraction steps. The loamy soil released 70% of its total nitrate amount in subsequent extractions, the biochar-amended soil 58%. However, biochar amendment doubled the amount of total extractable nitrate. Thus, biochar nitrate capture can be a relevant contribution to the overall nitrate retention in agroecosystems. Our results also indicate that the total nitrate amount in biochar amended soils and composts may frequently be underestimated. Furthermore, biochars could prevent nitrate loss from agroecosystems and may be developed into slow-release fertilizers to reduce global N fertilizer demands.

Nitrate capture and slow release in biochar amended compost and soil

PubMed Central

Kammann, Claudia I.; Schmidt, Hans-Peter; Kappler, Andreas; Behrens, Sebastian

2017-01-01

Slow release of nitrate by charred organic matter used as a soil amendment (i.e. biochar) was recently suggested as potential mechanism of nutrient delivery to plants which may explain some agronomic benefits of biochar. So far, isolated soil-aged and composted biochar particles were shown to release considerable amounts of nitrate only in extended (>1 h) extractions (“slow release”). In this study, we quantified nitrate and ammonium release by biochar-amended soil and compost during up to 167 h of repeated extractions in up to six consecutive steps to determine the effect of biochar on the overall mineral nitrogen retention. We used composts produced from mixed manures amended with three contrasting biochars prior to aerobic composting and a loamy soil that was amended with biochar three years prior to analysis and compared both to non-biochar amended controls. Composts were extracted with 2 M KCl at 22°C and 65°C, after sterilization, after treatment with H2O2, after removing biochar particles or without any modification. Soils were extracted with 2 M KCl at 22°C. Ammonium was continuously released during the extractions, independent of biochar amendment and is probably the result of abiotic ammonification. For the pure compost, nitrate extraction was complete after 1 h, while from biochar-amended composts, up to 30% of total nitrate extracted was only released during subsequent extraction steps. The loamy soil released 70% of its total nitrate amount in subsequent extractions, the biochar-amended soil 58%. However, biochar amendment doubled the amount of total extractable nitrate. Thus, biochar nitrate capture can be a relevant contribution to the overall nitrate retention in agroecosystems. Our results also indicate that the total nitrate amount in biochar amended soils and composts may frequently be underestimated. Furthermore, biochars could prevent nitrate loss from agroecosystems and may be developed into slow-release fertilizers to reduce global N fertilizer demands. PMID:28199354

Impact of biochar application on nitrogen nutrition of rice, greenhouse-gas emissions and soil organic carbon dynamics in two paddy soils of China

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xie, Zubin; Xu, Yanping; Liu, Gang

Two field microcosm experiments and 15N labeling techniques were used to investigate the first-year effects of biochar addition on rice N nutrition and GHG emissions in an Inceptisol and an Ultisol. Biochar N bioavailability and effect of biochar on fertilizer nitrogen-use efficiency (NUE) were studied by 15N-enriched wheat biochar (7.8803 atom% 15N) and fertilizer urea (5 atom% 15N) (Experiment I). Corn biochar and corn stalks were applied at 12 Mg ha-1 to study their effects on GHG emissions (Experiment II). Biochar had no significant impact on rice production and less than 2% of the biochar N was available to plantsmore » in the first season. Biochar addition increased soil C and N contents and decreased urea NUE.. Seasonal cumulative CH4 emissions with biochar were similar to the controls, but significantly lower than the local practice of straw amendment. Soil emissions of N2O with biochar amendment were similar to the control in the acidic Ultisol, but significantly higher in the slightly alkaline Inceptisol. Carbon-balance calculations found no major losses of biochar-C. Low bio-availability of biochar N did not make a significant impact on rice production or N nutrition during the first year.. Replacement of straw amendments with biochar could decrease CH4 emissions and increase SOC stocks.« less

Application of Rice-Straw Biochar and Microorganisms in Nonylphenol Remediation: Adsorption-Biodegradation Coupling Relationship and Mechanism

PubMed Central

Lou, Liping; Yao, Lingdan; Cheng, Guanghuan; Wang, Lixiao; He, Yunfeng; Hu, Baolan

2015-01-01

Biochar adsorption presents a potential remediation method for the control of hydrophobic organic compounds (HOCs) pollution in the environment. It has been found that HOCs bound on biochar become less bioavailable, so speculations have been proposed that HOCs will persist for longer half-life periods in biochar-amended soil/sediment. To investigate how biochar application affects coupled adsorption-biodegradation, nonylphenol was selected as the target contaminant, and biochar derived from rice straw was applied as the adsorbent. The results showed that there was an optimal dosage of biochar in the presence of both adsorption and biodegradation for a given nonylphenol concentration, thus allowing the transformation of nonylphenol to be optimized. Approximately 47.6% of the nonylphenol was biodegraded in two days when 0.005 g biochar was added to 50 mg/L of nonylphenol, which was 125% higher than the relative quantity biodegraded without biochar, though the resistant desorption component of nonylphenol reached 87.1%. All adsorptive forms of nonylphenol (f rap, f slow, f r) decreased gradually during the biodegradation experiment, and the resistant desorption fraction of nonylphenol (f r) on biochar could also be biodegraded. It was concluded that an appropriate amount of biochar could stimulate biodegradation, not only illustrating that the dosage of biochar had an enormous influence on the half-life periods of HOCs but also alleviating concerns that enhanced HOCs binding by biochar may cause secondary pollution in biochar-modified environment. PMID:26348485

Transport and retention of bacteria and viruses in biochar-amended sand.

PubMed

Sasidharan, Salini; Torkzaban, Saeed; Bradford, Scott A; Kookana, Rai; Page, Declan; Cook, Peter G

2016-04-01

The transport and retention of Escherichia coli and bacteriophages (PRD1, MS2 and ФX174), as surrogates for human pathogenic bacteria and viruses, respectively, were studied in the sand that was amended with several types of biochar produced from various feedstocks. Batch and column studies were conducted to distinguish between the role of attachment and straining in microbe retention during transport. Batch experiments conducted at various solution chemistries showed negligible attachment of viruses and bacteria to biochar before or after chemical activation. At any given solution ionic strength, the attachment of viruses to sand was significantly higher than that of biochar, whereas bacteria showed no attachment to either sand or biochar. Consistent with batch results, biochar addition (10% w/w) to sand reduced virus retention in the column experiments, suggesting a potential negative impact of biochar application to soil on virus removal. In contrast, the retention of bacteria was enhanced in biochar-amended sand columns. However, elimination of the fine fraction (<60μm) of biochar particles in biochar-amended sand columns significantly reduced bacteria retention. Results from batch and column experiments suggest that land application of biochar may only play a role in microbe retention via straining, by alteration of pore size distribution, and not via attachment. Consequently, the particle size distribution of biochar and sediments is a more important factor than type of biochar in determining whether land application of biochar enhances or diminishes microbial retention. Copyright © 2016 Elsevier B.V. All rights reserved.

Turning Waste Chemicals into Wealth-A New Approach To Synthesize Efficient Cathode Material for an Li-O2 Battery.

PubMed

Yao, Ying; Wu, Feng

2017-09-20

An Li-O 2 battery requires the oxygen-breathing cathode to be highly electronically conductive, rapidly oxygen diffusive, structurally stable, and often times electrocatalytically active. Catalyst-decorated porous carbonaceous materials are the chosen air cathode in this regard. Alternatively, biomass-derived carbonaceous materials possess great ability to remove heavy and toxic metal ions from waste, forming a metal-adsorbed porous carbonaceous material. The similar structure between the air cathode and the metal-adsorbed biomass-derived carbon nicely bridges these two irrelevant areas. In this study, we investigated the electrochemical activity of a biochar material Ag-ESB directly synthesized from ethanol sludge residue in a rechargeable aprotic Li-O 2 battery. Ag ions were adsorbed from sewage and became Ag nanoparticles with uniform coverage on the biochar surface. The as-prepared material exhibits good electrochemical behavior in battery testing, especially toward the battery efficiency and cyclability. This study provides the possibility of synthetically efficient cathode material by reusing "waste" such as biofuel sludge residue. It is an economically and environmentally friendly approach both for an energy-storage system and for waste recycling.

Turning Waste Chemicals into Wealth—A New Approach To Synthesize Efficient Cathode Material for an Li–O 2 Battery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yao, Ying; Wu, Feng

An Li–O 2 battery requires the oxygen-breathing cathode to be highly electronically conductive, rapidly oxygen diffusive, structurally stable, and often times electrocatalytically active. Catalyst-decorated porous carbonaceous materials are the chosen air cathode in this regard. Alternatively, biomass-derived carbonaceous materials possess great ability to remove heavy and toxic metal ions from waste, forming a metal-adsorbed porous carbonaceous material. The similar structure between the air cathode and the metal-adsorbed biomass-derived carbon nicely bridges these two irrelevant areas. In this study, we investigated the electrochemical activity of a biochar material Ag-ESB directly synthesized from ethanol sludge residue in a rechargeable aprotic Li–O 2more » battery. Ag ions were adsorbed from sewage and became Ag nanoparticles with uniform coverage on the biochar surface. The as-prepared material exhibits good electrochemical behavior in battery testing, especially toward the battery efficiency and cyclability. This study provides the possibility of synthetically efficient cathode material by reusing “waste” such as biofuel sludge residue. It is an economically and environmentally friendly approach both for an energy-storage system and for waste recycling.« less

Environmental benefits of biochar.

PubMed

Ippolito, James A; Laird, David A; Busscher, Warren J

2012-01-01

Understanding and improving environmental quality by reducing soil nutrient leaching losses, reducing bioavailability of environmental contaminants, sequestering C, reducing greenhouse gas emissions, and enhancing crop productivity in highly weathered or degraded soils, has been the goal of agroecosystem researchers and producers for years. Biochar, produced by pyrolysis of biomass, may help attain these goals. The desire to advance understanding of the environmental and agronomic implication of biochar utilization led to the organization of the 2010 American Society of Agronomy-Soil Science Society of America Environmental Quality Division session titled "Biochar Effects on the Environment and Agricultural Productivity." This specialized session and sessions from other biochar conferences, such as the 2010 U.S. Biochar Initiative and the Biochar Symposium 2010 are the sources for this special manuscript collection. Individual contributions address improvement of the biochar knowledge base, current information gaps, and future biochar research needs. The prospect of biochar utilization is promising, as biochars may be customized for specific environmental applications. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Particulate matter emissions from biochar-amended soils as a potential tradeoff to the negative emission potential

NASA Astrophysics Data System (ADS)

Ravi, Sujith; Sharratt, Brenton S.; Li, Junran; Olshevski, Stuart; Meng, Zhongju; Zhang, Jianguo

2016-10-01

Novel carbon sequestration strategies such as large-scale land application of biochar may provide sustainable pathways to increase the terrestrial storage of carbon. Biochar has a long residence time in the soil and hence comprehensive studies are urgently needed to quantify the environmental impacts of large-scale biochar application. In particular, black carbon emissions from soils amended with biochar may counteract the negative emission potential due to the impacts on air quality, climate, and biogeochemical cycles. We investigated, using wind tunnel experiments, the particulate matter emission potential of a sand and two agriculturally important soils amended with different concentrations of biochar, in comparison to control soils. Our results indicate that biochar application considerably increases particulate emissions possibly by two mechanisms-the accelerated emission of fine biochar particles and the generation and emission of fine biochar particles resulting from abrasion of large biochar particles by sand grains. Our study highlights the importance of considering the background soil properties (e.g., texture) and geomorphological processes (e.g., aeolian transport) for biochar-based carbon sequestration programs.

Effects and optimization of the use of biochar in anaerobic digestion of food wastes.

PubMed

Cai, Jiao; He, Pinjing; Wang, Ying; Shao, Liming; Lü, Fan

2016-05-01

The addition of various amounts of biochar to anaerobic digestion of food wastes at different ratios of inoculum to substrate (ISR) was investigated to evaluate the effect of biochar as a functional additive and to optimize the additive dosage of biochar. The biochar treatments at ISR 2, 1, and 0.8 shortened the lag phase of digestion by -20.0%-10.9%, 43.3%-54.4%, and 36.3%-54.0%, and raised the maximum methane production rate by 100%-275%, 100%-133.3%, and 33.3%-100%, respectively, compared to control without biochar. Biochar also enhanced the degradation rate of dissolved organics and volatile fatty acids. Furthermore, the amount of biochar with best effectiveness at ISR = 2, 1, and 0.8 was 2.5, 0.625, and 0.5 g g(-1)-waste, respectively. Therefore, the effectiveness of biochar depended on the additive amount of biochar and at the same time the inoculum amount, implying a complementary role of abiotic biochar to biotic inoculum. © The Author(s) 2016.

Biochar production method and composition therefrom

DOEpatents

Lee, James W; Buchanan, III, Archibald C; Evans, Barbara R; Kidder, Michelle K

2014-04-29

The invention is directed to a method for producing an oxygenated biochar material possessing a cation-exchanging property, wherein a biochar source is reacted with one or more oxygenating compounds in such a manner that the biochar source homogeneously acquires oxygen-containing cation-exchanging groups in an incomplete combustion process. The invention is also directed to oxygenated biochar compositions and soil formulations containing the oxygenated biochar material.

Biochar production method and composition therefrom

DOEpatents

Lee, James W.; Buchanan, III, Archibald C.; Evans, Barbara R.; Kidder, Michelle K.

2013-03-19

The invention is directed to a method for producing an oxygenated biochar material possessing a cation-exchanging property, wherein a biochar source is reacted with one or more oxygenating compounds in such a manner that the biochar source homogeneously acquires oxygen-containing cation-exchanging groups in an incomplete combustion process. The invention is also directed to oxygenated biochar compositions and soil formulations containing the oxygenated biochar material.

Phosphorus-Assisted Biomass Thermal Conversion: Reducing Carbon Loss and Improving Biochar Stability

PubMed Central

Zhao, Ling; Cao, Xinde; Zheng, Wei; Kan, Yue

2014-01-01

There is often over 50% carbon loss during the thermal conversion of biomass into biochar, leading to it controversy for the biochar formation as a carbon sequestration strategy. Sometimes the biochar also seems not to be stable enough due to physical, chemical, and biological reactions in soils. In this study, three phosphorus-bearing materials, H3PO4, phosphate rock tailing (PRT), and triple superphosphate (TSP), were used as additives to wheat straw with a ratio of 1: 0.4–0.8 for biochar production at 500°C, aiming to alleviate carbon loss during pyrolysis and to increase biochar-C stabilization. All these additives remarkably increased the biochar yield from 31.7% (unmodified biochar) to 46.9%–56.9% (modified biochars). Carbon loss during pyrolysis was reduced from 51.7% to 35.5%–47.7%. Thermogravimetric analysis curves showed that the additives had no effect on thermal stability of biochar but did enhance its oxidative stability. Microbial mineralization was obviously reduced in the modified biochar, especially in the TSP-BC, in which the total CO2 emission during 60-d incubation was reduced by 67.8%, compared to the unmodified biochar. Enhancement of carbon retention and biochar stability was probably due to the formation of meta-phosphate or C-O-PO3, which could either form a physical layer to hinder the contact of C with O2 and bacteria, or occupy the active sites of the C band. Our results indicate that pre-treating biomass with phosphors-bearing materials is effective for reducing carbon loss during pyrolysis and for increasing biochar stabilization, which provides a novel method by which biochar can be designed to improve the carbon sequestration capacity. PMID:25531111

Promoting Interspecies Electron Transfer with Biochar

PubMed Central

Chen, Shanshan; Rotaru, Amelia-Elena; Shrestha, Pravin Malla; Malvankar, Nikhil S.; Liu, Fanghua; Fan, Wei; Nevin, Kelly P.; Lovley, Derek R.

2014-01-01

Biochar, a charcoal-like product of the incomplete combustion of organic materials, is an increasingly popular soil amendment designed to improve soil fertility. We investigated the possibility that biochar could promote direct interspecies electron transfer (DIET) in a manner similar to that previously reported for granular activated carbon (GAC). Although the biochars investigated were 1000 times less conductive than GAC, they stimulated DIET in co-cultures of Geobacter metallireducens with Geobacter sulfurreducens or Methanosarcina barkeri in which ethanol was the electron donor. Cells were attached to the biochar, yet not in close contact, suggesting that electrons were likely conducted through the biochar, rather than biological electrical connections. The finding that biochar can stimulate DIET may be an important consideration when amending soils with biochar and can help explain why biochar may enhance methane production from organic wastes under anaerobic conditions. PMID:24846283

The effect of biochar amendment on the soil microbial community - PLFA analyses and 13C labeling results

NASA Astrophysics Data System (ADS)

Watzinger, A.; Feichtmair, S.; Rempt, F.; Anders, E.; Wimmer, B.; Kitzler, B.; Zechmeister-Boltenstern, S.; Horacek, M.; Zehetner, F.; Kloss, S.; Richoz, S.; Soja, G.

2012-04-01

The effects of biochar amendment on plant growth and on the chemical / physical soil characteristics are well explored but only few studies have investigated the impact on soil microorganisms. The response of the soil microbial community to biochar amendment was investigated by phospholipid fatty acid (PLFA) analysis in (i) a large scale pot experiment, (ii) a small scale pot experiment using 13C labeled biochar and (iii) an incubation study using 13C labeled biochar. In the large scale pot experiment, three different agricultural soils from Austria (Planosol, Cambisol, Chernozem) and four different types of biochar were investigated. In total, 25 treatments with 5 replicates each were set up and monitored over a year. The results from the pot experiments showed no significant influence of biochar amendment on the total microbial biomass in the first 100 days after biochar addition. However, discriminant analysis showed a distinction of biochar and control soils as well as a strong effect of the pyrolysis temperature on the microbial composition. The effect of biochar was dependent on the type of soil. In the Planosol, some PLFAs were affected positively, especially when adding biochar with a low pyrolysis temperature, in the first month. In the long term, microbial community composition altered. Growth of fungi and gram negative bacteria was enhanced. In the Chernozem, PLFAs from various microbial groups decreased in the long term. Variability in the incubation study was low. Consequently, many PLFAs were significantly affected by biochar amendment. Again, in the Planosol, gram negative bacteria, actinomycetes and, after 2 weeks, gram positive bacteria increased under biochar amendment whereas in the chernozem total microbial biomass and gram positive bacteria were negatively affected in the long term. The 13C labeling studies confirmed the low degradability of the biochar, i.e. no alteration of the content and the δ13C in the soil organic matter within 100 days, decreased CO2 emission after biochar addition and little 13C signature from the biochar in the respired CO2. The uptake of the labeled biochar into the microbial PLFAs was analysed and will provide an evidence if biochar was used as a carbon source. In addition, the long term effect of biochar amendment (beyond 100 days) on the soil microbial community is currently investigated. These results will be also presented in the oncoming meeting.

[Influences of biochar and nitrogen fertilizer on soil nematode assemblage of upland red soil].

PubMed

Lu, Yan-yan; Wang, Ming-wei; Chen, Xiao-vun; Liu, Man-qiang; Chen, Xiao-min; Cheng, Yan-hong; Huang, Qian-ru; Hu, Feng

2016-01-01

The use of biochar as soil remediation amendment has received more and more concerns, but little attention has been paid to its effect on soil fauna. Based on the field experiment in an upland red soil, we studied the influences of different application rates of biochar (0, 10, 20, 30, 40 t · hm⁻²) and nitrogen fertilizer (60, 90, 120 kg N · hm⁻²) on soil basic properties and nematode assemblages during drought and wet periods. Our results showed that the biochar amendment significantly affect soil moisture and pH regardless of drought or wet period. With the increasing of biochar application, soil pH significantly increased, while soil moisture increased first and then decreased. Soil microbial properties (microbial biomass C, microbial biomass N, microbial biomass C/N, basal respiration) were also significantly affected by the application of biochar and N fertilizer. Low doses of biochar could stimulate the microbial activity, while high doses depressed microbial activity. For example, averaged across different N application rates, biochar amendment at less than 30 t · hm⁻² could increase microbial activity in the drought and wet periods. Besides, the effects of biochar also depended on wet or drought period. When the biochar application rate higher than 30 t · hm⁻², the microbial biomass C was significantly higher in the drought period than the control, but no differences were observed in the wet period. On the contrary, microbial biomass N showed a reverse pattern. Dissolved organic matter and mineral N were affected by biochar and N fertilizer significantly in the drought period, however, in the wet period they were only affected by N fertilizer rather than biochar. There was significant interaction between biochar and N fertilizer on soil nematode abundance and nematode trophic composition independent of sampling period. Combined high doses of both biochar and N fertilization promoted soil nematode abundance. Moreover, the biochar amendment increased the proportion of fungivores especially in the drought period, suggesting the biochar was the preferred fungal energy channel in comparison to soil without biochar addition. In summary, complex patterns occurred not only due to the application rate of biochar as well as their interactions with N fertilization but also due to the drought and wet periods. It is, therefore, necessary to consider different ecological factors when evaluating the effects of biochar in future.

Influence of biochar on volatile fatty acids accumulation and microbial community succession during biosolids composting.

PubMed

Awasthi, Mukesh Kumar; Awasthi, Sanjeev Kumar; Wang, Quan; Wang, Zhen; Lahori, Altaf Hussain; Ren, Xiuna; Chen, Hongyu; Wang, Meijing; Zhao, Junchao; Zhang, Zengqiang

2018-03-01

The impact of biochar amendment on volatile fatty acids (VFAs) and odor generation during the biosolids-wheat straw composting was investigated. Five treatments were design using the same mixture of biosolids-wheat straw with different dosage of biochar blending (2%, 4%, 8% and 12% on dry weight basis) and without biochar applied treatment served as control. The results of VFAs and Odour Index (OI) profile designated that compost with 8-12% biochar became more rapidly humified with less quantity of VFAs and OI generation content compared to control. Consequently, the VFAs degrading and total bacterial abundance are also significantly higher recorded in 8-12% biochar than 2% biochar and control. In addition, 8-12% biochar applied treatment has significantly maximum close correlation among the all physicochemical and gaseous emission parameters. Finally, results designated that higher dosage of biochar (8-12% biochar) was more feasible approach for biosolids composting. Copyright © 2017 Elsevier Ltd. All rights reserved.

AMOchar: Amorphous manganese oxide coating of biochar improves its efficiency at removing metal(loid)s from aqueous solutions.

PubMed

Trakal, Lukáš; Michálková, Zuzana; Beesley, Luke; Vítková, Martina; Ouředníček, Petr; Barceló, Andreu Piqueras; Ettler, Vojtěch; Číhalová, Sylva; Komárek, Michael

2018-06-01

A novel sorbent made from biochar modified with an amorphous Mn oxide (AMOchar) was compared with pure biochar, pure AMO, AMO+biochar mixtures and biochar+birnessite composite for the removal of various metal(loid)s from aqueous solutions using adsorption and solid-state analyses. In comparison with the pristine biochar, both Mn oxide-biochar composites were able to remove significantly greater quantities of various metal(loid)s from the aqueous solutions, especially at a ratio 2:1 (AMO:biochar). The AMOchar proved most efficient, removing almost 99, 91 and 51% of Pb, As and Cd, respectively. Additionally, AMOchar and AMO+biochar mixture exhibited reduced Mn leaching, compared to pure AMO. Therefore, it is concluded that the synthesis of AMO and biochar is able to produce a double acting sorbent ('dorbent') of enhanced efficiency, compared with the individual deployment of their component materials. Copyright © 2017 Elsevier B.V. All rights reserved.

Can biochar serve as a toop to reduce soil GHG costs of agricultural production in the long term?

NASA Astrophysics Data System (ADS)

Kammann, Claudia; Finke, Christoph; Schröder, Matthias; Schmidt, Hans-Peter; Lima, Amanda; Teixeira, Wenceslau; Clough, Tim; Müller, Christoph

2013-04-01

With a growing world population and growing demands for bioenergy there is an urgent need to improve the greenhouse gas (GHG) emission-to-yield ratio of agricultural production. 'Young, production-fresh biochar has repeatedly been observed to reduce N2O emissions in a variety of agricultural soils, but it is unknown how long initial N2O-reducing effects will persist. Biochar-amended soils may even develop a potential for higher N2O emissions decades after Biochar application due to the formation of higher soil organic matter stocks when mineral N is applied. Unfortunately the longest-running field trials are not older than a few years, thus our ability for predictions is rather limited. To investigate the long-term effect that Biochar addition to soils may have on soil GHG emissions we conducted three different laboratory incubation studies with potential 'long-term analogs' that may offer insights: (I) N-rich Biochar-manure compost, versus pure manure-compost, or manure-compost were the same amount of untreated, fresh Biochar was added; (II) temperate soil from a 100-year old charcoal making (kiln) site in Germany compared to the original adjacent forest soil; and (III) two tropical Terra preta soils (secondary forest and cultivation) compared to their respective adjacent ferralsols. None of the studies indicated that old, "aged" Biochar in soils or substrates will increase the risk for N2O losses. The Biochar-compost (I) still had significantly reduced N2O emissions, or was the same as the control. However, its biological activity (respiration) was significantly increased (122% of ctrl). In contrast, the fresh Biochar addition significantly reduced N2O emissions to 39% of the control, accompanied by significantly reduced respiration rates (50% of ctrl.). The kiln-area soil (II), compared to the corresponding adjacent forest soil (both at 60% of their respective WHCmax), did not exhibit higher N2O emissions after N-fertilization over the course of one month. The kiln soils' NH4+ concentration, net nitrification and respiration, and also its methane consumption activity were all significantly increased but the labile organic-C content was reduced. The overall N2O+CH4 greenhouse gas balance of the kiln soil (expressed in CO2 equivalents) was significantly improved over that of the adjacent forest soil. Terra preta soils (III) did not show an increased potential for N2O formation before or after NH4NO3 application. Only the adjacent secondary-forest soil exhibited a sharp but quickly declining N2O emission peak. Here, again, the biological activity of the Terra preta soils was always greater than those of the corresponding adjacent ferralsols. We therefore conclude that, although the initial N2O-emission reducing capability of (untreated) biochar additions will not last forever, the danger of accelerated N2O formation in Biochar-amended soils will likely not be large in the long run. Moreover, the improved CO2-to-N2O emission-ratios (soil respiration, as an indicator for soil fertility) observed throughout the investigated analogs in space and time provide room for careful optimism that biochar may indeed be a suitable management tool to improve GHG-emission-to-yield ratios of agricultural production in the long run.

Biochar particle size, shape, and porosity act together to influence soil water properties

PubMed Central

Dugan, Brandon; Masiello, Caroline A.; Gonnermann, Helge M.

2017-01-01

Many studies report that, under some circumstances, amending soil with biochar can improve field capacity and plant-available water. However, little is known about the mechanisms that control these improvements, making it challenging to predict when biochar will improve soil water properties. To develop a conceptual model explaining biochar’s effects on soil hydrologic processes, we conducted a series of well constrained laboratory experiments using a sand matrix to test the effects of biochar particle size and porosity on soil water retention curves. We showed that biochar particle size affects soil water storage through changing pore space between particles (interpores) and by adding pores that are part of the biochar (intrapores). We used these experimental results to better understand how biochar intrapores and biochar particle shape control the observed changes in water retention when capillary pressure is the main component of soil water potential. We propose that biochar’s intrapores increase water content of biochar-sand mixtures when soils are drier. When biochar-sand mixtures are wetter, biochar particles’ elongated shape disrupts the packing of grains in the sandy matrix, increasing the volume between grains (interpores) available for water storage. These results imply that biochars with a high intraporosity and irregular shapes will most effectively increase water storage in coarse soils. PMID:28598988

Persistence in soil of Miscanthus biochar in laboratory and field conditions

PubMed Central

Budai, Alice; O’Toole, Adam; Ma, Xingzhu; Rumpel, Cornelia; Abiven, Samuel

2017-01-01

Evaluating biochars for their persistence in soil under field conditions is an important step towards their implementation for carbon sequestration. Current evaluations might be biased because the vast majority of studies are short-term laboratory incubations of biochars produced in laboratory-scale pyrolyzers. Here our objective was to investigate the stability of a biochar produced with a medium-scale pyrolyzer, first through laboratory characterization and stability tests and then through field experiment. We also aimed at relating properties of this medium-scale biochar to that of a laboratory-made biochar with the same feedstock. Biochars were made of Miscanthus biomass for isotopic C-tracing purposes and produced at temperatures between 600 and 700°C. The aromaticity and degree of condensation of aromatic rings of the medium-scale biochar was high, as was its resistance to chemical oxidation. In a 90-day laboratory incubation, cumulative mineralization was 0.1% for the medium-scale biochar vs. 45% for the Miscanthus feedstock, pointing to the absence of labile C pool in the biochar. These stability results were very close to those obtained for biochar produced at laboratory-scale, suggesting that upscaling from laboratory to medium-scale pyrolyzers had little effect on biochar stability. In the field, the medium-scale biochar applied at up to 25 t C ha-1 decomposed at an estimated 0.8% per year. In conclusion, our biochar scored high on stability indices in the laboratory and displayed a mean residence time > 100 years in the field, which is the threshold for permanent removal in C sequestration projects. PMID:28873471

Biochar-Induced Changes in Soil Hydraulic Conductivity and Dissolved Nutrient Fluxes Constrained by Laboratory Experiments

PubMed Central

Barnes, Rebecca T.; Gallagher, Morgan E.; Masiello, Caroline A.; Liu, Zuolin; Dugan, Brandon

2014-01-01

The addition of charcoal (or biochar) to soil has significant carbon sequestration and agronomic potential, making it important to determine how this potentially large anthropogenic carbon influx will alter ecosystem functions. We used column experiments to quantify how hydrologic and nutrient-retention characteristics of three soil materials differed with biochar amendment. We compared three homogeneous soil materials (sand, organic-rich topsoil, and clay-rich Hapludert) to provide a basic understanding of biochar-soil-water interactions. On average, biochar amendment decreased saturated hydraulic conductivity (K) by 92% in sand and 67% in organic soil, but increased K by 328% in clay-rich soil. The change in K for sand was not predicted by the accompanying physical changes to the soil mixture; the sand-biochar mixture was less dense and more porous than sand without biochar. We propose two hydrologic pathways that are potential drivers for this behavior: one through the interstitial biochar-sand space and a second through pores within the biochar grains themselves. This second pathway adds to the porosity of the soil mixture; however, it likely does not add to the effective soil K due to its tortuosity and smaller pore size. Therefore, the addition of biochar can increase or decrease soil drainage, and suggests that any potential improvement of water delivery to plants is dependent on soil type, biochar amendment rate, and biochar properties. Changes in dissolved carbon (C) and nitrogen (N) fluxes also differed; with biochar increasing the C flux from organic-poor sand, decreasing it from organic-rich soils, and retaining small amounts of soil-derived N. The aromaticity of C lost from sand and clay increased, suggesting lost C was biochar-derived; though the loss accounts for only 0.05% of added biochar-C. Thus, the direction and magnitude of hydraulic, C, and N changes associated with biochar amendments are soil type (composition and particle size) dependent. PMID:25251677

Influence of conventional biochar and ageing biochar application to arable soil on soil fertility and plant yield

NASA Astrophysics Data System (ADS)

Dvořáčková, Helena; Záhora, Jaroslav; Elbl, Jakub; Kynický, Jindřich; Hladký, Jan; Brtnický, Martin

2017-04-01

Biochar represents very controversial material which is product of pyrolysis. According to many studies biochar has positive effect on physical and chemical properties such as pH, conductivity, aggregates stability etc. Unfortunately biochar is product of combustion, so it can content toxic substance as are aromatic compound. These substances may have a negative effect on yield and microbial activities in soil. Our aim was eliminated concentration of toxic compound but preserved positive effect of biochar on soil properties. We was ageing/ activating of biochar in water environment and for soil inoculum we used native soil from landscape. Moreover two types of biochar was tested by pot experiment with seven variants, where conventional biochar from residual biomass and ageing biochar were applied in different doses: 10 t/ha, 20t/ha and 50 t/ha. Pots were placed in green house for 90 days and after the end of experiment the following parameters of soil fertility, health and quality were evaluated: content of soil organic matter, arbuscular mycorrhizal colonisation of Lactuca sativa L. roots, leaching of mineral nitrogen, changes in plant available nutrient content, EC and pH. Above all the total yield of indicator plant was observed. The significant (P < 0.05) differences in plant yield and soil properties were found. The application of conventional biochar didn't have positive effect on plant yield in comparison with ageing biochar. The positive effect of ageing biochar addition on soil fertility was directly proportional to the dose which were applied - increasing in dose of ageing biochar resulted in increase of plant yield. Moreover the special experimental containers were used, where we was able to monitor the development of root in soil with and without addition of biochar (conventional or ageing). The positive influence of ageing biochar addition into soil on development of Lactuca sativa L. roots was observed.

The Role of Actinobacteria in Biochar Decomposition in a Mediterranean Grassland Soil

NASA Astrophysics Data System (ADS)

Brodie, E. L.; Lim, H.; Bill, M.; Castanha, C.; Conrad, M. E.; Schmidt, M. W.; Abiven, S.; Jansson, J. K.; Torn, M. S.

2012-12-01

Biochar addition to soil has been proposed as an attractive approach for carbon sequestration, particularly in concert with bioenergy biomass production and conversion. Biochar, partially combusted organic material, is assumed to be recalcitrant in soil but studies show significant variation in residence times. The controls on biochar C stabilization are likely complex interactions among the substrate, microbial activities, and the soil chemical and physical environment. However, there is a lack of understanding regarding the impact of biochar on soil microbial populations, the organisms that may be responsible for its mineralization or the factors regulating the rate of biochar mineralization. In this study we amended a Mediterranean grassland soil (Ultic Haploxeralf) with biochar (dried chestnut pyrolized at 450°C for 5h) or non-pyrolized oak at ratios of either 1:9 or 1:2 relative to native organic carbon. Both wood and biochar resulted in a significant and dose dependent alteration of microbial community composition within 1 week relative to controls. The rate of change of microbial composition was slower for biochar than for non-pyrolized wood but in both cases Actinobacteria showed significant enrichment relative to controls. From the same grassland soils, we then isolated bacteria capable of subsisting on biochar as a sole C or N source, many of which were Actinobacteria. We selected one Streptomyces isolate and confirmed using 13C-labeled biochar that this strain was capable of biochar mineralization, and show that mineralization was accelerated in the presence of an additional carbon source. We also detected significant abiotic CO2 loss from biochar during incubations. This study demonstrates that some soil Actinobacteria can subsist on biochar as a sole C source, mineralizing it to CO2, our data also shows that priming of biochar decomposition can occur. Overall this highlights the important roles that microbial composition and resource availability may have in regulating biochar carbon stability in soils.

Sorption, Uptake, and Translocation of Pharmaceuticals across Multiple Interfaces in Soil Environment

NASA Astrophysics Data System (ADS)

Zhang, W.; Liu, C. H.; Bhalsod, G.; Zhang, Y.; Chuang, Y. H.; Boyd, S. A.; Teppen, B. J.; Tiedje, J. M.; Li, H.

2015-12-01

Pharmaceuticals are contaminants of emerging concern frequently detected in soil and water environments, raising serious questions on their potential impact on human and ecosystem health. Overuse and environmental release of antibiotics (i.e., a group of pharmaceuticals extensively used in human medicine and animal agriculture) pose enormous threats to the health of human, animal, and the environment, due to proliferation of antibiotic resistant bacteria. Recently, we have examined interactions of pharmaceuticals with soil geosorbents, bacteria, and vegetable crops in order to elucidate pathways of sorption, uptake, and translocation of pharmaceuticals across the multiple interfaces in soils. Sorption of pharmaceuticals by biochars was studied to assess the potential of biochar soil amendment for reducing the transport and bioavailability of antibiotics. Our preliminary results show that carbonaceous materials such as biochars and activated carbon had strong sorption capacities for antibiotics, and consequently decreased the uptake and antibiotic resistance gene expression by an Escherichia coli bioreporter. Thus, biochar soil amendment showed the potential for reducing selection pressure on antibiotic resistant bacteria. Additionally, since consumption of pharmaceutical-tainted food is a direct exposure pathway for humans, it is important to assess the uptake and accumulation of pharmaceuticals in food crops grown in contaminated soils or irrigated with reclaimed water. Therefore, we have investigated the uptake and accumulations of pharmaceuticals in greenhouse-grown lettuce under contrasting irrigation practices (i.e., overhead or surface irrigations). Preliminary results indicate that greater pharmaceutical concentrations were measured in overhead irrigated lettuce than in surface irrigated lettuce. This could have important implications when selecting irrigation scheme to use the reclaimed water for crop irrigation. In summary, proper soil and water management is needed to minimize the transfer of pharmaceuticals from soil and water to biota.

Fate and Transport of 17β-estradiol Beneath Animal Waste Holding Ponds

NASA Astrophysics Data System (ADS)

Gibson, L. A.; Tyner, J. S.; Hawkins, S. A.; Lee, J.; Buchanan, J. R.

2011-12-01

Steroidal hormones, such as 17β-estradiol (E2), are prevalent in animal waste and are a common subject of study due to potential stream and groundwater contamination. These particular hormones are labeled as Endocrine Disrupting Chemicals (EDCs) because of their developmental effects in reptiles and amphibians. Dairy waste at concentrated animal feeding operations is typically stored in a pond that is regulated by law to include an underlying soil liner with a minimal hydraulic conductivity to limit leaching beneath the pond, yet some studies have traced stream and groundwater contamination to these ponds. Previous studies have shown that the soil underlying earthen ponds are always unsaturated. This increases the pore water velocity relative to a given flux, which itself is dictated almost entirely by an organic seal that forms at the bottom of a waste pond. This increased velocity results in more rapid transport and less retention time within the vadose zone where E2 could biodegrade into its daughter product, estrone (E1). And since the soil is unsaturated and therefore has a negative pressure, preferential flow should not serve as a method of transport. On the contrary, E2 and E1 may sorb to mobile colloids increasing their mobility. This study will evaluate the use of biochar, an increasingly common activated carbon source, as a soil liner amendment. Biochar has a specific surface area that can exceed 1,500 m2/g and is high in organic matter, which E2 sorbs to strongly. The biochar amendment should be most effective and enduring as a layer located at the bottom of the soil liner so that the leachate has been treated by the soil prior to contact. Another proposed amendment technique is to uniformly mix the biochar within the soil liner to increase the leachate contact time with the biochar, but realistically could prove to be too costly and energy-intensive. Field and laboratory studies were conducted to analyze hormone persistence and transport processes and to evaluate the effectiveness of biochar as a remediation practice. 80 cm long soil cores were collected beneath an active dairy waste storage pond and analyzed for moisture content, E1, and E2 concentrations. A laboratory soil column study was also conducted, including intact soil cores from the field, sand and clay packed columns, and packed soil columns with powdered biochar as a layer at the bottom of the columns and also as a uniformly mixed soil amendment to test its ability in retarding E2. A 2.3 m column of waste was maintained on all soil columns for three months, leachate was analyzed, and the columns were dissected for moisture content and E2 and E1 concentration profiles at the conclusion of the study. Preliminary results will be presented from these studies. With a better understanding of persistence and transport processes, remediation techniques can be applied and evaluated for their effectiveness in retarding (and degrading) these environmentally harmful EDCs.

Removal of acetaminophen and naproxen by combined coagulation and adsorption using biochar: influence of combined sewer overflow components.

PubMed

Jung, Chanil; Oh, Jeill; Yoon, Yeomin

2015-07-01

The combined coagulation and adsorption of targeted acetaminophen and naproxen using activated biochar and aluminum sulfate were studied under various synthetic "combined sewer overflow" (CSO) conditions. The biochar demonstrated better adsorption performance for both acetaminophen and naproxen (removal, 94.1 and 97.7%, respectively) than that of commercially available powdered activated carbon (removal, 81.6 and 94.1%, respectively) due to superior carbonaceous structure and surface properties examined by nuclear magnetic resonance analysis. The adsorption of naproxen was more favorable, occupying active adsorption sites on the adsorbents by naproxen due to its higher adsorption affinity compared to acetaminophen. Three classified CSO components (i.e., representing hydrophobic organics, hydrophilic organics, and inorganics) played different roles in the adsorption of both adsorbates, resulted in inhibition by humic acid complexation or metal ligands and negative electrostatic repulsion under adsorption and coagulation combined system. Adsorption alone with biochar was determined to be the most effective adsorptive condition for the removal of both acetaminophen and naproxen under various CSO conditions, while both coagulation alone and combined adsorption and coagulation failed to remove the acetaminophen and naproxen adequately due to an increase in ionic strength in the presence of spiked aluminum species derived from the coagulant.

Crop yield responses to a hardwood biochar across varied soils and climate conditions

USDA-ARS?s Scientific Manuscript database

Biochars applied to soil for crop yield improvements have produced mixed results. The assorted crop yield responses may be linked to employing biochars with diverse chemical and physical characteristics. To clarify if biochars can improve crop yields, it may be prudent to evaluate one biochar type...

Maize, switchgrass, and ponderosa pine biochar added to soil increased herbicide sorption and decreased herbicide efficacy.

PubMed

Clay, Sharon A; Krack, Kaitlynn K; Bruggeman, Stephanie A; Papiernik, Sharon; Schumacher, Thomas E

2016-08-02

Biochar, a by-product of pyrolysis made from a wide array of plant biomass when producing biofuels, is a proposed soil amendment to improve soil health. This study measured herbicide sorption and efficacy when soils were treated with low (1% w/w) or high (10% w/w) amounts of biochar manufactured from different feedstocks [maize (Zea mays) stover, switchgrass (Panicum vigatum), and ponderosa pine (Pinus ponderosa)], and treated with different post-processing techniques. Twenty-four hour batch equilibration measured sorption of (14)C-labelled atrazine or 2,4-D to two soil types with and without biochar amendments. Herbicide efficacy was measured with and without biochar using speed of seed germination tests of sensitive species. Biochar amended soils sorbed more herbicide than untreated soils, with major differences due to biochar application rate but minor differences due to biochar type or post-process handling technique. Biochar presence increased the speed of seed germination compared with herbicide alone addition. These data indicate that biochar addition to soil can increase herbicide sorption and reduce efficacy. Evaluation for site-specific biochar applications may be warranted to obtain maximal benefits without compromising other agronomic practices.

Novel biochar-concrete composites: Manufacturing, characterization and evaluation of the mechanical properties.

PubMed

Akhtar, Ali; Sarmah, Ajit K

2018-03-01

In this study, biochar, a carbonaceous solid material produced from three different waste sources (poultry litter, rice husk and pulp and paper mill sludge) was utilized to replace cement content up to 1% of total volume and the effect of individual biochar mixed with cement on the mechanical properties of concrete was investigated through different characterization techniques. A total of 168 samples were prepared for mechanical testing of biochar added concrete composites. The results showed that pulp and paper mill sludge biochar at 0.1% replacement of total volume resulted in compressive strength close to the control specimen than the rest of the biochar added composites. However, rice husk biochar at 0.1% slightly improved the splitting tensile strength with pulp and papermill sludge biochar produced comparable values. Biochar significantly improved the flexural strength of concrete in which poultry litter and rice husk biochar at 0.1% produced optimum results with 20% increment than control specimens. Based on the findings, we conclude that biochar has the potential to improve the concrete properties while replacing the cement in minor fractions in conventional concrete applications. Copyright © 2017 Elsevier B.V. All rights reserved.

Mechanisms of nitrate capture in biochar: Are they related to biochar properties, post-treatment and soil environment?

NASA Astrophysics Data System (ADS)

Cimo, Giulia; Haller, Andreas; Spokas, Kurt; Novak, Jeff; Ippolito, Jim; Löhnertz, Otmar; Kammann, Claudia

2017-04-01

Biochar use in soils is assumed to increase soil fertility and the efficiency of nutrient use, particularly nitrogen. It was demonstrated recently that biochar is able to capture considerable amounts of the mobile anion nitrate which was observed in co-composted as well as field aged biochar1,2. Moreover the nitrate was not sufficiently extractable with standard methods from biochar particles; extractions had to be repeated to effectively remove the nitrate1. Subsequently the co-composted nitrate-enriched biochar stimulated plant growth due to N supply to the plants2. However, in a field study in sandy soil in Germany, a different biochar also captured nitrate, increasing the topsoil nitrate concentration and likely reducing nitrate leaching to subsoils1. This was particularly seen after a dry year in the re-picked and analysed particles. However, in the field experiment this aged, nitrate-enriched biochar did not improve crop yields3. To better understand the way biochar interacts with nitrate we undertook several laboratory experiments with 13 well characterized biochars produced from cypress, pine and grapewood at 350, 500, 700 and 900 °C including one Kon-Tiki produced grapewood biochar (600-700°C). Our results showed that (1) pure, pristine (not post-treated) biochar captured more nitrate when they were air-moist and not totally dry; that (2) letting biochar particles dry in nitrate solution forces more nitrate into biochar particles than incubating them in the solution, but (3) that shaking during drying nevertheless caused a higher nitrate uptake into biochar particles; that(4) the counter ion K+ in nitrate solution was more effective than Na+ for N-loading of biochar; (5)that drying a soil-biochar mix in nitrate solution produced a higher nitrate loading of the mixture (i.e. the biochar) than drying both components separately in the same solution; (6)that a higher biochar production temperature caused higher nitrate capture up to 700-900°C. Furthermore we found (7)that this captured nitrate was well protected against leaching, (8)that repeated drying-wetting cycles increased nitrate capture, with the amount protected against leaching remaining more or less constant; and (9) that an organic "coating" (or application of the nitrate in an organic solution, here: black tea) increased biochars' capability of nitrate capture. Our results thus underline that the phenomenon of nitrate capture is not purely due to ionic mechanisms but may partly rely on physical interactions and the pore structure of the biochar. Acknowledgement: JC acknowledges funding by the COST action TD1107 (short term scientific mission), CK acknowledges the financial support of DFG grant no. Ka3442/1-1 and of the HMWK Hessia funded OptiChar4EcoVin project. 1-Haider, G., Steffens, D., Müller, C. & Kammann, C. I. Standard extraction methods may underestimate nitrate stocks captured by field aged biochar. J. Environ. Qual. 45, 1196-1204 (2016). 2-Kammann, C. I. et al. Plant growth improvement mediated by nitrate capture in co-composted biochar. Scientific Reports 5, doi: 10.1038/srep11080 (2015). 3-Haider, G., Steffens, D., Moser, G., Müller, C. & Kammann, C. I. Biochar reduced nitrate leaching and improved soil moisture content without yield improvements in a four-year field study. Agri. Ecosys. Environ. 237, 80-94 (2017).