Soil biota response to amendment with biochar as P and K fertilizer

NASA Astrophysics Data System (ADS)

Winding, Anne; Imparato, Valentina; Santos, Susana; Hansen, Veronika; Haugaard-Nielsen, Henrik; Browne, Patrick; Hestbjerg Hansen, Lars; Henning Krogh, Paul; Johansen, Anders

2017-04-01

Thermal gasification converts biomass into a combustible gas at oxygen-poor conditions, the bi-product being biochar which can be used as soil amendment to increase pH, sequester carbon to mitigate climate change, and supply phosphate and potassium to crops; replacing chemical or other alternative organic fertilizers. Amending soil with biochar can support three soil functions: production of food, carbon sequestration, and biodiversity. This was tested in a field experiment with reduced-tillage agricultural management, where the effect of biochar amendment on soil ecosystem services, especially biodiversity and carbon sequestration were studied. The effects on soil microorganisms and fauna (protists and earthworms) were assessed with activity based assays and Next Generation Sequencing (NGS). Crops were alternating oil seed rape and winter wheat, and biochar was added annually for 3 years. The soil was a sandy loam soil with SOM content of ca. 5%. Earthworms and soil were sampled from field plots either left untreated, amended with straw or annually amended with either 6-8 t ha-1 or ca. 1 t ha-1 biochar. Soil was sampled from bulk soil and earthworm drilosphere. Earthworms had a priming effect on protist abundance and basal soil respiration. However, in biochar amended soil the protist abundance decreased in the drilosphere. Culturable bacteria and extracellular enzymatic activities were not significantly affected by earthworms. The abundance of only one earthworm species increased at high compared to low application levels of biochar, while still not differing from controls without biochar. Thus, no harmful effects were detected for earthworms. At the lower biochar amendment, significant changes were observed for the activity of a few selected enzymes related to biochar and also a relative increase in abundance of low abundant microorganisms was seen. At the high doses of biochar the abundance of protists increased compared to control. NGS analysis was more sensitive than activity based functional assays as metagenomics of bacterial communities (16S rDNA) revealed effects of biochar and metagenomics of fungi/protist communities (18S rDNA) revealed effects of biochar and less priming effects of earthworms. Generally, the addition of biochar as soil amendment and alternative fertilizer had limited effect on soil microorganisms and fauna in the tested agricultural soil, and could be a sustainable P and K fertilizer while sequestering carbon to mitigate climate change.

Zinc and glycerol enhance the production of nematicidal compounds in vitro and improve the biocontrol of Meloidogyne javanica in tomato by fluorescent pseudomonads.

PubMed

Siddiqui, I A; Shaukat, S S

2002-01-01

To assess the effects of various carbon and mineral sources on the nematicidal potential of biocontrol inoculants of Pseudomonas aeruginosa IE-6S+ and Ps. fluorescens CHA0 under laboratory and glasshouse conditions. Culture filtrates of strains IE-6S+ and CHA0, cultured in nutrient yeast extract broth, caused substantial mortality of the juveniles of Meloidogyne javanica. The nematicidal activities of the culture filtrates were altered after amendment with various carbon and mineral sources. Soil amendment with zinc alone or in combination with glycerol improved the biocontrol efficacy against root-knot nematode, promoted tomato plant growth and enhanced bacterial rhizosphere and endophytic colonization. Appropriate quantities of glycerol and zinc alone or in combination enhance the nematicidal activity of Ps. aeruginosa and Ps. fluorescens. Glucose reduces the activity of these bacteria against nematodes. Minerals and carbon sources are appealing because they are easy and economical to provide during liquid fermentation of inoculants or as fertilizer amendments to improve the biocontrol activity of indigenous and introduced bacteria.

Fungal Denitrification Activity in Vertical Flow Constructed Wetlands as Impacted by Plant Species Richness, Carbon, Nitrogen and pH Amendments.

PubMed

Liu, W L; Zhang, C B; Han, W J; Guan, M; Liu, S Y; Ge, Y; Chang, J

2017-12-01

To control potential fungal denitrification rate (PFDR) in vertical flow simulated wetlands (VFSW) microcosms, thirty VFSW microcosms were established and planted with three plant species richness levels (i.e. unplanted, monoculture, and four-species polyculture treatment), and effects of carbon, nitrogen and pH amendments on the PFDR were investigated using a room-incubating method. Among seven carbon compounds, sodium citrate, glycerol, glucose and sodium succinate were more effective in enhancing PFDRs. These enhanced effects were dependant on a given species richness level. Sodium nitrite mostly stimulated PFDRs to a greater extent than the other three nitrogen compound amendments at any richness level. Treatments with pH 5.6 or 8.4 had significantly greater PFDRs than the treatment with pH 2.8 in the three species richness levels. However, no effect of plant species richness on the PFDR was observed among any carbon, nitrogen and pH amendments. Current results suggest carbon, nitrogen and pH factors should be considered when mediating fungal denitrification in VFSW microcosms.

Activated carbon amendment to sequester PAHs in contaminated soil: a lysimeter field trial.

PubMed

Hale, Sarah E; Elmquist, Marie; Brändli, Rahel; Hartnik, Thomas; Jakob, Lena; Henriksen, Thomas; Werner, David; Cornelissen, Gerard

2012-04-01

Activated carbon (AC) amendment is an innovative method for the in situ remediation of contaminated soils. A field-scale AC amendment of either 2% powder or granular AC (PAC and GAC) to a PAH contaminated soil was carried out in Norway. The PAH concentration in drainage water from the field plot was measured with a direct solvent extraction and by deploying polyoxymethylene (POM) passive samplers. In addition, POM samplers were dug directly in the AC amended and unamended soil in order to monitor the reduction in free aqueous PAH concentrations in the soil pore water. The total PAH concentration in the drainage water, measured by direct solvent extraction of the water, was reduced by 14% for the PAC amendment and by 59% for GAC, 12 months after amendment. Measurements carried out with POM showed a reduction of 93% for PAC and 56% for GAC. The free aqueous PAH concentration in soil pore water was reduced 93% and 76%, 17 and 28 months after PAC amendment, compared to 84% and 69% for GAC. PAC, in contrast to GAC, was more effective for reducing freely dissolved concentrations than total dissolved ones. This could tentatively be explained by leaching of microscopic AC particles from PAC. Secondary chemical effects of the AC amendment were monitored by considering concentration changes in dissolved organic carbon (DOC) and nutrients. DOC was bound by AC, while the concentrations of nutrients (NO(3), NO(2), NH(4), PO(4), P-total, K, Ca and Mg) were variable and likely affected by external environmental factors. Copyright © 2012 Elsevier Ltd. All rights reserved.

Comparing black carbon types in sequestering polybrominated diphenyl ethers (PBDEs) in sediments

PubMed Central

Jia, Fang; Gan, Jay

2014-01-01

Polybrominated diphenyl ethers (PBDEs) are widely found in sediments, especially congeners from the penta-BDE formula. Due to their strong affinity for black carbon (BC), bioavailability of PBDEs may be decreased in BC-amended sediments. In this study, we used a matrix-SPME method to measure the freely dissolved concentration (Cfree) of PBDEs as a parameter of their potential bioavailability and evaluated the differences among biochar, charcoal, and activated carbon. Activated carbon displayed a substantially greater sequestration capacity than biochar or charcoal. At 1% amendment rate in sediment with low organic carbon (OC) content (0.12%), Cfree of six PBDEs was reduced by 47.5–78.0%, 47.3–77.5%, and 94.1–98.3% with biochar, charcoal, and activated carbon, respectively, while the sequestration was more limited in sediment with high OC content (0.87%). Therefore, it is important to consider the type and properties of the BC and the sediment in BC-based remediation or mitigation. PMID:24047549

Damage identification in cement paste amended with carbon nanotubes

NASA Astrophysics Data System (ADS)

Soltangharaei, Vafa; Anay, Rafal; Assi, Lateef; Ziehl, Paul; Matta, Fabio

2018-04-01

Cement-based composites have been used as reliable materials in building and civil engineering infrastructure for many decades. Although there are several advantages, some drawbacks such as premature cracking may be problematic for sensitive applications such as those found in nuclear power plants or associated waste storage facilities. In this study, acoustic emission monitoring was employed to detect stress waves associated with damage progression during uniaxial compressive loading. Acoustic emission data resulting from loading of plain cement paste prisms and cement paste prisms amended with carbon nanotubes are compared. Unsupervised pattern recognition is employed to categorize the data. Results indicate that increased acoustic emission activity was recorded for the plain cement paste prisms when compared to prisms amended with carbon nanotubes.

The effect of compost on carbon cycling and the active soil microbiota

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

Singer, Esther; Woyke, Tanja; Ryals, Rebecca

2014-09-02

Rangelands cover an estimated 40-70percent of global landmass, approximately one-third of the landmass of the United States and half of California. The soils of this vast land area has high carbon (C) storage capacity, which makes it an important target ecosystem for the mitigation of greenhouse gas emission and effects on climate change, in particular under land management techniques that favor increased C sequestration rates. While microbial communities are key players in the processes responsible for C storage and loss in soils, we have barely shed light on these highly complex processes in part due to the tremendous and seeminglymore » intractable diversity of microbes, largely uncultured, that inhabit soil ecosystems. In our study, we compare Mediterranean grassland soil plots that were amended with greenwaste compost in a single event 6 years ago. Subsampling of control and amended plots was performed in depth increments of 0-10 cm. We present data on greenhouse gas emissions and budgets of carbon, nitrogen, phosphorus, and micronutrients in dependence of compost amendment. Changes in the active members of the soil microbial community were assessed using a novel approach combining flow cytometry and 16S tag sequencing disclosing who is active. This is the first study revealing the nature of actively metabolizing microbial community members linked to the geochemical characteristics of compost-amended soil.« less

Effect of biochar or activated carbon amendment on the volatilisation and biodegradation of organic soil pollutants

NASA Astrophysics Data System (ADS)

Werner, David; Meynet, Paola; Bushnaf, Khaled

2013-04-01

Biochar or activated carbon added to contaminated soil may temporarily reduce the volatilisation of organic pollutants by enhanced sorption. The long-term effect of sorbent amendments on the fate of volatile petroleum hydrocarbon mixtures (VPHs) will depend on the responses of the soil bacterial community members, especially those which may utilize VPHs as carbon substrates. We investigated the volatilisation and biodegradation of VPHs emanating from NAPL sources and migrating through one meter long columns containing unsaturated sandy soil with and without 2% biochar or activated carbon amendment. After 420 days, VPH volatilisation from AC amended soil was less than 10 percent of the cumulative VPH volatilisation flux from unamended soil. The cumulative CO2 volatilisation flux increased more slowly in AC amended soil, but was comparable to the untreated soil after 420 days. This indicated that the pollution attenuation over a 1 meter distance was improved by the AC amendment. Biochar was a weaker VPH sorbent than AC and had a lesser effect on the cumulative VPH and CO2 fluxes. We also investgated the predominant bacterial community responses in sandy soil to biochar and/or VPH addition with a factorially designed batch study, and by analyzing preserved soil samples. Biochar addition alone had only weak effects on soil bacterial communities, while VPH addition was a strong community structure shaping factor. The bacterial community effects of biochar-enhanced VPH sorption were moderated by the limited biomass carrying capacity of the sandy soil investigated which contained only low amounts of inorganic nitrogen. Several Pseudomonas spp., including Pseudomonas putida strains, became dominant in VPH polluted soil with and without biochar. The ability of these versatile VPH degraders to effectively regulate their metabolic pathways according to substrate availabilities may additionally have moderated bacterial community structure responses to the presence of biochar in VPH polluted soil.

Effect of Activated Carbon Amendment on Bacterial Community Structure and Functions in a PAH Impacted Urban Soil

PubMed Central

2012-01-01

We collected urban soil samples impacted by polycyclic aromatic hydrocarbons (PAHs) from a sorbent-based remediation field trial to address concerns about unwanted side-effects of 2% powdered (PAC) or granular (GAC) activated carbon amendment on soil microbiology and pollutant biodegradation. After three years, total microbial cell counts and respiration rates were highest in the GAC amended soil. The predominant bacterial community structure derived from denaturing gradient gel electrophoresis (DGGE) shifted more strongly with time than in response to AC amendment. DGGE band sequencing revealed the presence of taxa with closest affiliations either to known PAH degraders, e.g. Rhodococcus jostii RHA-1, or taxa known to harbor PAH degraders, e.g. Rhodococcus erythropolis, in all soils. Quantification by real-time polymerase chain reaction yielded similar dioxygenases gene copy numbers in unamended, PAC-, or GAC-amended soil. PAH availability assessments in batch tests showed the greatest difference of 75% with and without biocide addition for unamended soil, while the lowest PAH availability overall was measured in PAC-amended, live soil. We conclude that AC had no detrimental effects on soil microbiology, AC-amended soils retained the potential to biodegrade PAHs, but the removal of available pollutants by biodegradation was most notable in unamended soil. PMID:22455603

Effect of activated carbon amendment on bacterial community structure and functions in a PAH impacted urban soil.

PubMed

Meynet, Paola; Hale, Sarah E; Davenport, Russell J; Cornelissen, Gerard; Breedveld, Gijs D; Werner, David

2012-05-01

We collected urban soil samples impacted by polycyclic aromatic hydrocarbons (PAHs) from a sorbent-based remediation field trial to address concerns about unwanted side-effects of 2% powdered (PAC) or granular (GAC) activated carbon amendment on soil microbiology and pollutant biodegradation. After three years, total microbial cell counts and respiration rates were highest in the GAC amended soil. The predominant bacterial community structure derived from denaturing gradient gel electrophoresis (DGGE) shifted more strongly with time than in response to AC amendment. DGGE band sequencing revealed the presence of taxa with closest affiliations either to known PAH degraders, e.g. Rhodococcus jostii RHA-1, or taxa known to harbor PAH degraders, e.g. Rhodococcus erythropolis, in all soils. Quantification by real-time polymerase chain reaction yielded similar dioxygenases gene copy numbers in unamended, PAC-, or GAC-amended soil. PAH availability assessments in batch tests showed the greatest difference of 75% with and without biocide addition for unamended soil, while the lowest PAH availability overall was measured in PAC-amended, live soil. We conclude that AC had no detrimental effects on soil microbiology, AC-amended soils retained the potential to biodegrade PAHs, but the removal of available pollutants by biodegradation was most notable in unamended soil. © 2012 American Chemical Society

Field-scale reduction of PCB bioavailability with activated carbon amendment to river sediments.

PubMed

Beckingham, Barbara; Ghosh, Upal

2011-12-15

Remediation of contaminated sediments remains a technological challenge because traditional approaches do not always achieve risk reduction goals for human health and ecosystem protection and can even be destructive for natural resources. Recent work has shown that uptake of persistent organic pollutants such as polychlorinated biphenyls (PCBs) in the food web is strongly influenced by the nature of contaminant binding, especially to black carbon surfaces in sediments. We demonstrate for the first time in a contaminated river that application of activated carbon to sediments in the field reduces biouptake of PCBs in benthic organisms. After treatment with activated carbon applied at a dose similar to the native organic carbon of sediment, bioaccumulation in freshwater oligochaete worms was reduced compared to preamendment conditions by 69 to 99%, and concentrations of PCBs in water at equilibrium with the sediment were reduced by greater than 93% at all treatment sites for up to three years of monitoring. By comparing measured reductions in bioaccumulation of tetra- and penta-chlorinated PCB congeners resulting from field application of activated carbon to a laboratory study where PCBs were preloaded onto activated carbon, it is evident that equilibrium sorption had not been achieved in the field. Although other remedies may be appropriate for some highly contaminated sites, we show through this pilot study that PCB exposure from moderately contaminated river sediments may be managed effectively through activated carbon amendment in sediments.

Biochemical activity and chemical-structural properties of soil organic matter after 17 years of amendments with olive-mill pomace co-compost.

PubMed

Aranda, V; Macci, C; Peruzzi, E; Masciandaro, G

2015-01-01

This study evaluates soil fertility, biochemical activity and the soil's ability to stabilize organic matter after application of composted olive-mill pomace. This organic amendment was applied in two different olive groves in southern Spain having different soil typologies (carbonated and silicic). Olive grove soils after 17 years of organic management with application of olive-mill pomace co-compost were of higher quality than those with conventional management where no co-compost had been applied. The main chemical parameters studied (total organic carbon, total nitrogen, available phosphorus, exchangeable bases, cation exchange capacity, total extractable carbon (TEC), and humic-to-fulvic acids ratio), significantly increased in soils treated with the organic amendment. In particular, the more resistant pool of organic matter (TEC) enhanced by about six and eight fold in carbonated and silicic soils, respectively. Moreover, the amended silicic soils showed the most significant increases in enzyme activities linked to C and P cycles (β-glucosidase twenty-five fold higher and phosphatase seven fold higher). Organic management in both soils induced higher organic matter mineralization, as shown by the higher pyrrole/phenol index (increasing 40% and 150% in carbonated and silicic soils, respectively), and lower furfural/pyrrole index (decreasing 27% and 71% in carbonated and silicic soils, respectively). As a result of mineralization, organic matter incorporated was also more stable as suggested by the trend of the aliphatic/aromatic index (decreasing 36% and 30% in carbonated and silicic soils, respectively). Therefore, management system and soil type are key factors in increasing long-term C stability or sequestration in soils. Thus application of olive-oil extraction by-products to soils could lead to important mid-to -long-term agro-environmental benefits, and be a valuable alternative use for one of the most widespread polluting wastes in the Mediterranean region. Copyright © 2014 Elsevier Ltd. All rights reserved.

Organic nitrogen rearranges both structure and activity of the soil-borne microbial seedbank

PubMed Central

Leite, Márcio F. A.; Pan, Yao; Bloem, Jaap; Berge, Hein ten; Kuramae, Eiko E.

2017-01-01

Use of organic amendments is a valuable strategy for crop production. However, it remains unclear how organic amendments shape both soil microbial community structure and activity, and how these changes impact nutrient mineralization rates. We evaluated the effect of various organic amendments, which range in Carbon/Nitrogen (C/N) ratio and degradability, on the soil microbiome in a mesocosm study at 32, 69 and 132 days. Soil samples were collected to determine community structure (assessed by 16S and 18S rRNA gene sequences), microbial biomass (fungi and bacteria), microbial activity (leucine incorporation and active hyphal length), and carbon and nitrogen mineralization rates. We considered the microbial soil DNA as the microbial seedbank. High C/N ratio favored fungal presence, while low C/N favored dominance of bacterial populations. Our results suggest that organic amendments shape the soil microbial community structure through a feedback mechanism by which microbial activity responds to changing organic inputs and rearranges composition of the microbial seedbank. We hypothesize that the microbial seedbank composition responds to changing organic inputs according to the resistance and resilience of individual species, while changes in microbial activity may result in increases or decreases in availability of various soil nutrients that affect plant nutrient uptake. PMID:28198425

Organic nitrogen rearranges both structure and activity of the soil-borne microbial seedbank.

PubMed

Leite, Márcio F A; Pan, Yao; Bloem, Jaap; Berge, Hein Ten; Kuramae, Eiko E

2017-02-15

Use of organic amendments is a valuable strategy for crop production. However, it remains unclear how organic amendments shape both soil microbial community structure and activity, and how these changes impact nutrient mineralization rates. We evaluated the effect of various organic amendments, which range in Carbon/Nitrogen (C/N) ratio and degradability, on the soil microbiome in a mesocosm study at 32, 69 and 132 days. Soil samples were collected to determine community structure (assessed by 16S and 18S rRNA gene sequences), microbial biomass (fungi and bacteria), microbial activity (leucine incorporation and active hyphal length), and carbon and nitrogen mineralization rates. We considered the microbial soil DNA as the microbial seedbank. High C/N ratio favored fungal presence, while low C/N favored dominance of bacterial populations. Our results suggest that organic amendments shape the soil microbial community structure through a feedback mechanism by which microbial activity responds to changing organic inputs and rearranges composition of the microbial seedbank. We hypothesize that the microbial seedbank composition responds to changing organic inputs according to the resistance and resilience of individual species, while changes in microbial activity may result in increases or decreases in availability of various soil nutrients that affect plant nutrient uptake.

Influence of soil properties on heavy metal sequestration by biochar amendment: 2. copper desorption isotherms

USDA-ARS?s Scientific Manuscript database

Contaminant desorption constrains the long-term effectiveness of remediation technologies, and is strongly influenced by dynamic non-equilibrium states of environmental and biological media. Information is currently lacking in the influence of biochar and activated carbon amendments on desorption of...

Effects of Temperature and Acidic Pre-Treatment on Fenton-Driven Oxidation of MTBE-Spent Granular Activated Carbon

EPA Science Inventory

Temperature-dependent mechanisms in the Fenton-driven chemical oxidation of methyl tert-butyl ether (MTBE)-spent granular activated carbon (GAC) was investigated. Prior to iron (Fe) amendment to the GAC, acid-treatment altered the surface chemistry of the GAC and lowered the pH ...

Effects on temperature and acidic pre-treatment on Fenton-driven oxidation of MTBE-spent granular activated carbon

EPA Science Inventory

Temperature-dependent mechanisms in the Fenton-driven chemical oxidation of methyl tert-butyl ether (MTBE)-spent granular activated carbon (GAC) was investigated. Prior to iron (Fe) amendment to the GAC, acid-treatment altered the surface chemistry of the GAC and lowered the p...

Activated carbon amendment for in-situ remediation

NASA Astrophysics Data System (ADS)

Elmquist, M.; Brändli, R.; Henriksen, T.; Hartnik, T.; Cornelissen, G.

2009-04-01

For the first time in Europe, a novel and innovative remediation technique is used in a field pilot study. This technique is amendment of the soil with two types of activated carbon (AC). Here, one pulverized AC (PAC, 50% < 15µm and 3% >150 µm) and one granular AC (GAC, 1.7-0.43 mm) is tested. The idea of this technique is that the added AC binds organic contaminants so strongly that they cannot be taken up in living organisms or transported to other environmental compartments. Laboratory studies with 2% (wt %) AC amendment to an urban soil reduced the freely dissolved pore water concentrations of PAH by 17% to 99% (Brändli et al. 2008). Several parameters such as dissolved organic carbon (DOC), K, NO2, NO3, NH4, PO4 and PAH, are being measured in this field study. Plant growth and earthworm bioaccumulation tests were also carried out during the summer months. DOC showed a 70% reduction between untreated soil and soil with PAC about one year after the amendment. In the soil mixed with GAC, a 55% reduction could be measured. For K, a 40% lowering value was observed for the soil with GAC compared to no affect for the soil with PAC. NH4 was reduced by 50% for both GAC and PAC amended soils compared to the untreated soil, whereas NO2 and NO3 increased with 2-4 times for the soil with GAC and no effect were seen for the soil with PAC. The freely dissolved PAH concentrations were reduced by 49-78% for the soil with GAC and 82-96% for the soil with PAC. The plant experiment showed best growth rate in the soil with GAC, followed by the untreated soil and least growth was measured on the PAC treated soil. The low growth rate seen in the soil with PAC may come from the fact that DOC and some other nutrients are also being sorbed to the PAC surface together with the organic pollutants and are thereby taken away from the biological cycle. Amendment of soil with AC remediates the soil from organic contaminants when these pollutants are sorbed to the AC surface. This is an easy technique that can be performed to a relatively low cost. However, the AC particles may also sorb other constituents of the effluent water such as DOC and nutrients which in turn may lead to reduced plant growth rate. Therefore, the long-term effects of this amendment technique have to be studied more closely. Reference Rahel C. Brändli, Thomas Hartnik, Thomas Henriksen, Gerard Cornelissen, (2008) Sorption of native polyaromatic hydrocarbons (PAH) to black carbon and amended activated carbon in soil, Chemosphere doi:10.1016/j.chemosphere.2008.08.034

Utilization of biochar and activated carbon to reduce Cd, Pb and Zn phytoavailability and phytotoxicity for plants.

PubMed

Břendová, Kateřina; Zemanová, Veronika; Pavlíková, Daniela; Tlustoš, Pavel

2016-10-01

In the present study, the content of risk elements and content of free amino acids were studied in spinach (Spinacia oleracea L.) and mustard (Sinapis alba L.) subsequently grown on uncontaminated and contaminated soils (5 mg Cd/kg, 1000 mg Pb/kg and 400 mg Zn/kg) with the addition of activated carbon (from coconut shells) or biochar (derived from local wood residues planted for phytoextaction) in different seasons (spring, summer and autumn). The results showed that activated carbon and biochar increased biomass production on contaminated site. Application of amendments decreased Cd and Zn uptake by spinach plants. Mustard significantly increased Pb accumulation in the biomass as well in subsequently grown autumn spinach. Glutamic acid and glutamine were major free amino acids in leaves of all plants (15-34% and 3-45%) from total content. Application of activated carbon and biochar increased content of glutamic acid in all plants on uncontaminated and contaminated soils. Activated carbon and biochar treatments also induced an increase of aspartic acid in spinach plants. Biochar produced from biomass originated from phytoextraction technologies promoted higher spinach biomass yield comparing unamended control and showed a tendency to reduce accumulation of cadmium and zinc and thus it is promising soil amendment. Copyright © 2016. Published by Elsevier Ltd.

Fenton-driven regeneration of MTBE-spent granular activated carbon - Effects of particle size and Iron Amendment Procedures

EPA Science Inventory

Fenton-driven regeneration of spent granular activated carbon (GAC) is a technology being developed to regenerate organic contaminant-spent GAC. Here, the effect of GAC particle size (>2 mm to <0.35 mm) on Fenton-driven oxidation of methyl tert-butyl ether (MTBE)-spent GAC was ev...

The effect of compost on carbon cycling in soil

NASA Astrophysics Data System (ADS)

Singer, E.; Woyke, T.

2013-12-01

Rangelands cover an estimated 40-70% of global landmass, approximately one-third of the landmass of the United States and half of California. The soils of this vast land area has high carbon (C) storage capacity, which makes it an important target ecosystem for the mitigation of greenhouse gas emission and effects on climate change, in particular under land management techniques that favor increased C sequestration rates. While microbial communities are key players in the processes responsible for C storage and loss in soils, we have barely shed light on these highly complex processes in part due to the tremendous and seemingly intractable diversity of microbes, largely uncultured, that inhabit soil ecosystems. In our study, we compare Mediterranean grassland soil plots that were amended with greenwaste of various C:N ratios and biochar in a single event. Monthly subsampling of control and amended plots over the course of three months was performed in depth increments of 0-12 cm and 12-24 cm. We present data on greenhouse gas emissions and budgets of carbon, nitrogen, phosphorus, and micronutrients in dependence of amendment types and seasonality. Changes in the active members of the soil microbial community were assessed using a novel approach combining flow cytometry and metagenomic sequencing disclosing 'who does what'. This is the first study revealing the nature of actively metabolizing microbial community members linked to the geochemical characteristics of compost-amended soil.

Influence of biochar and plant growth on organic matter dynamics in a reclaimed mine residue

NASA Astrophysics Data System (ADS)

Moreno-Barriga, Fabián; Díaz, Vicente; Alberto, Jose; Faz, Ángel; Zornoza, Raúl

2016-04-01

This study aims at assessing the impact of biochar and marble waste amendment and the development of vegetation in acidic mine wastes on organic matter dynamics. For this purpose, a mine residue was collected in a tailing pond from the Sierra Minera of Cartagena-La Unión (SE Spain), and a greenhouse experiment was established for 120 days. Marble waste (MW) was added in a rate of 200 g kg-1 as a source of calcium carbonate to increase the pH from 3 to 7.5-8 (average pH in the native soils of the area). We added biochar as a source of organic carbon and nutrients, in two different rates, 50 g kg-1 (BC1) and 100 g kg-1 (BC2). To assess the influence of vegetation growth on the creation of a technosoil from mine residues and its impact on organic matter dynamics, the plant species Piptatherum miliaceum (PM) was planted in half the pots with the different amendments. Thus, five treatments were established: unamended and unplanted control (CT), BC1, BC2, BC1+PM and BC2+PM. Results showed that the different treatments had no significant effect on aggregates stability, microbial biomass carbon and the emission of N2O and CH4. So, it seems that longer periods are needed to increase the stability of aggregates and microbial populations, since even the combined use of biochar, marble waste and vegetation was not enough to increase these properties in 120 days. Nonetheless, it was positive that the addition of biochar and the release of root exudates did not trigger the emission of greenhouse gases. Organic carbon significantly increased with the addition of biochar, with values similar to the dose applied, indicating high stability and low mineralization of the amendment. The addition of amendments significantly increased arylesterase activity, while the growth of the plant was needed to significantly increase β-glucosidase activity. The soluble carbon significantly decreased in BC1 and BC2 with regards to CT, while no significant differences were observed among CT and treatments with plant. Arylestarase showed significant correlations with pH and organic carbon, while β-glucosidase was related to total and soluble organic carbon. Thus, the high recalcitrance of biochar increased the total organic carbon, but decreased soluble carbon, likely by adsorption, and was not able to activate microbial populations. A labile source of organic matter should be added together with the proposed amendments to promote the activation of microbial communities and likely the formation of stable aggregates, since root exudates were not enough for this purpose. Acknowledgement : This work has been funded by Fundación Séneca (Agency of Science and Technology of the Region of Murcia, Spain) by the project 18920/JLI/13

Stimulation of the anaerobic digestion of the dry organic fraction of municipal solid waste (OFMSW) with carbon-based conductive materials.

PubMed

Dang, Yan; Sun, Dezhi; Woodard, Trevor L; Wang, Li-Ying; Nevin, Kelly P; Holmes, Dawn E

2017-08-01

Growth of bacterial and archaeal species capable of interspecies electron exchange was stimulated by addition of conductive materials (carbon cloth or granular activated carbon (GAC)) to anaerobic digesters treating dog food (a substitute for the dry-organic fraction of municipal solid waste (OFMSW)). Methane production (772-1428mmol vs <80mmol), volatile solids removal (78%-81% vs 54%-64%) and COD removal efficiencies (∼80% vs 20%-30%) were all significantly higher in reactors amended with GAC or carbon cloth than controls. OFMSW degradation was also significantly accelerated and VFA concentrations were substantially lower in reactors amended with conductive materials. These results suggest that both conductive materials (carbon cloth and GAC) can promote conversion of OFMSW to methane even in the presence of extremely high VFA concentrations (∼500mM). Copyright © 2017 Elsevier Ltd. All rights reserved.

Short-term effects of different organic amendments on soil chemical, biochemical and biological indicators

NASA Astrophysics Data System (ADS)

Mondelli, Donato; Aly, Adel; Yirga Dagnachew, Ababu; Piscitelli, Lea; Dumontet, Stefano; Miano, Teodoro

2014-05-01

The limited availability of animal manure and the high cost of good quality compost lead to difficult soil quality management under organic agriculture. Therefore, it is important to find out alternative organic soil amendments and more flexible strategies that are able to sustain crop productivity and maintain and enhance soil quality. A three years study was carried out in the experimental fields of the Mediterranean Agronomic Institute of Bari located in Valenzano, Italy. The main objective of this research is to investigate the effects of different fertility management strategies on soil quality in order to estimate the role of innovative matrices for their use in organic farming. The experiment consists of seven treatments applied to a common crop rotation. The treatments include alternative organic amendments (1- olive mill wastewater OMW, 2- residues of mushroom cultivation MUS, 3- coffee chaff COF), common soil amendments (4- compost COM, 5- faba bean intercropping LEG, 6- cow manure - MAN) and as a reference treatment (7- mineral fertilizer COV). The soil quality was assessed before and after the application of the treatments, through biological (microbial biomass carbon and nitrogen, soil respiration and metabolic quotient), biochemical (soil enzymatic activities: β-glucosidase, alkaline phospatase, urease, fluorescein diacetate (FDA) hydrolysis), and chemical (pH, soil organic carbon, soil organic matter, total nitrogen, available phosphorous, exchangeable potassium, dissolved organic carbon and total dissolved nitrogen) indicators. Based on the results obtained after the second year, all treatments were able to improve various soil chemical parameters as compared to mineral fertilizer. The incorporation of COF and OMW seemed to be more effective in improving soil total N and exchangeable K, while MAN significantly increased available P. All the amendments enhance dissolved organic C, soil respiration, microbial biomass and metabolic quotient as compared to control soil. Results concerning biochemical indicators revealed that phosphatase and β-glycosidase were significantly reduced, while activities of urease and FDA were improved in all amended plots in comparison to the control, regardless of amendment type. Data demonstrated the efficiency, the high sensitivity and a quick response of the biochemical indicators in assessing soil quality changes. As a conclusion, it is possible to emphasize that alternative and common soil organic amendments behave similarly in enhancing the chemical, biochemical and biological properties. The alternative soil organic amendments could, then, be candidates for substituting some commonly used one which are currently showing shortage in their supply and a lowering in their quality. Keywords: Organic agriculture, Soil quality, Enzymatic activities, Olive mill wastewater, Residues of mushroom cultivation, Coffee chaff.

Bioaccessibility of polycyclic aromatic hydrocarbons in activated carbon or biochar amended vegetated (Salix viminalis) soil.

PubMed

Oleszczuk, Patryk; Godlewska, Paulina; Reible, Danny D; Kraska, Piotr

2017-08-01

The aim of the present study was to determine the effect of activated carbon (AC) or biochars on the bioaccessibility (C bioacc ) of polycyclic aromatic hydrocarbons (PAHs) in soils vegetated with willow (Salix viminalis). The study determined the effect of willow on the C bioacc PAHs and the effect of the investigated amendments on changes in dissolved organic carbon (DOC), crop yield and the content of PAHs in plants. PAH-contaminated soil was amended with 2.5 wt% AC or biochar. Samples from individual plots with and without plants were collected at the beginning of the experiment and after 3, 6, 12 and 18 months. The C bioacc PAHs were determined using sorptive bioaccessibility extraction (SBE) (silicon rods and hydroxypropyl-β-cyclodextrin). Both AC and biochar caused a decrease in the C bioacc PAHs. Immediately after adding AC, straw-derived biochar or willow-derived biochar to the soil, the reduction in the sum of 16 (Σ16) C bioacc PAHs was 70.3, 38.0, and 29.3%, respectively. The highest reduction of C bioacc was observed for 5- and 6-ring PAHs (from 54.4 to 100%), whereas 2-ring PAHs were reduced only 8.0-25.4%. The reduction of C bioacc PAHs increased over time. Plants reduced C bioacc in all soils although effects varied by soil treatment and PAH. Willow grown in AC- and biochar-amended soil accumulated less phenanthrene than in the control soil. The presence of AC in the soil also affected willow yield and shoot length and DOC was reduced from 53.5 to 66.9% relative to unamended soils. In the biochars-amended soil, no changes in soil DOC content were noted nor effects on willow shoot length. Copyright © 2017 Elsevier Ltd. All rights reserved.

PAH-sequestration capacity of granular and powder activated carbon amendments in soil, and their effects on earthworms and plants.

PubMed

Jakob, Lena; Hartnik, Thomas; Henriksen, Thomas; Elmquist, Marie; Brändli, Rahel C; Hale, Sarah E; Cornelissen, Gerard

2012-07-01

A field lysimeter study was carried out to investigate whether the amendment of 2% powder and granular activated carbon (PAC and GAC) to a soil with moderate PAH contamination had an impact on the PAH bioaccumulation of earthworms and plants, since AC is known to be a strong sorbent for organic pollutants. Furthermore, secondary effects of AC on plants and earthworms were studied through growth and nutrient uptake, and survival and weight gain. Additionally, the effect of AC amendments on soil characteristics like pH, water holding capacity, and the water retention curve of the soil were investigated. Results show that the amendment of 2% PAC had a negative effect on plant growth while the GAC increased the growth rate of plants. PAC was toxic to earthworms, demonstrated by a significant weight loss, while the results for GAC were less clear due to ambiguous results of a field and a parallel laboratory study. Both kinds of AC significantly reduced biota to soil accumulation factors (BSAFs) of PAHs in earthworms and plants. The GAC reduced the BSAFs of earthworms by an average of 47 ± 44% and the PAC amendment reduced them by 72 ± 19%. For the investigated plants the BSAFs were reduced by 46 ± 36% and 53 ± 22% by the GAC and PAC, respectively. Copyright © 2012 Elsevier Ltd. All rights reserved.

Use of cotton gin trash to enhance denitrification in restored forested wetlands

USGS Publications Warehouse

Ullah, S.; Faulkner, S.P.

2006-01-01

Lower Mississippi Valley (LMV) has lost about 80% bottomland hardwood forests, mainly to agriculture. This landscape scale alteration of the LMV resulted in the loss of nitrate (NO3) removal capacity of the valley, contributing to nitrogen (N)-enhanced eutrophication and potentially hypoxia in the northern Gulf of Mexico. Restoration of hardwood forests in the LMV is a highly recommended practice to reduce NO3 load of the Mississippi River. However, restored bottomland forests take decades to develop characteristic ecological functions including denitrifier activity. One way to enhance denitrifier activity in restored wetland forests is to amend the soils with an available carbon (C) source. This research investigated the effects of cotton gin trash (CGT) amendment on denitrification rate and N2O:N2 emission ratio from a restored bottomland forest soils and compared it to those from an adjacent unamended natural forest soils. CGT amendment increased denitrification rates in the restored forest soils to the level of the natural forest soils. N2O:N2 emission ratios from the restored and natural forest soils were highly variable and were not significantly different from each other. These findings suggest that restoration of bottomland hardwood forests in the LMV will require organic carbon amendment to achieve enhanced denitrifier activity for NO3 removal while the restored forest is developing into a mature state over time. ?? 2006 Elsevier B.V. All rights reserved.

Biochars mitigate greenhouse gas emissions and bioaccumulation of potentially toxic elements and arsenic speciation in Phaseolus vulgaris L.

PubMed

Ibrahim, Muhammad; Li, Gang; Khan, Sardar; Chi, Qiaoqiao; Xu, Yaoyang; Zhu, Yongguan

2017-08-01

Anthropogenic and natural activities can lead to increased greenhouse gas emissions and discharge of potentially toxic elements (PTEs) into soil environment. Biochar amendment to soils is a cost-effective technology and sustainable approach used to mitigate greenhouse gas emissions, improve phytoremediation, and minimize the health risks associated with consumption of PTE-contaminated vegetables. Greenhouse pot experiments were conducted to investigate the effects of peanut shell biochar (PNB) and sewage sludge biochar (SSB) on greenhouse gas (GHG) emissions, plant growth, PTE bioaccumulation, and arsenic (As) speciation in bean plants. Results indicated that amendments of PNB and SSB increased plant biomass production by increasing soil fertility and reducing bioavailability of PTEs. Addition of biochars also increased soil pH, total nitrogen (TN), total carbon (TC), dissolved organic carbon (DOC), and ammonium-nitrogen (NH 4 -N) but decreased available concentrations of PTEs such as cadmium (Cd), lead (Pb), and As. The concentration of nitrate-nitrogen (NO 3 - -N) was also decreased in biochar-amended soils. In addition, PNB and SSB amendments significantly (P < 0.01) reduced the bioaccumulation of chromium (Cr), As, Cd, Pb, and nickel (Ni) in stalks, leaves, and fruits of Phaseolus vulgaris L. Similarly, PNB and SSB amendments significantly (P ≤ 0.05) reduced inorganic As species like arsenite (As (III)) and arsenate (As (V)). Greenhouse gases such as carbon dioxide (CO 2 ) and methane (CH 4 ) emissions were significantly (P < 0.01) reduced but nitrous oxide (N 2 O) emissions first increased and then decreased amended with both biochars. Current findings demonstrate that SSB and PNB are two beneficial soil amendments simultaneous mitigating greenhouse gas emissions and PTE bioaccumulation as well as arsenic speciation in P. vulgaris L.

Effect of Soil Amendments on Microbial Resilience Capacity of Acid Soil Under Copper Stress.

PubMed

Mounissamy, Vassanda Coumar; Kundu, Samaresh; Selladurai, Rajendiran; Saha, Jayanta Kumar; Biswas, Ashish Kumar; Adhikari, Tapan; Patra, Ashok Kumar

2017-11-01

An incubation study was undertaken to study microbial resilience capacity of acid soil amended with farmyard manure (FYM), charcoal and lime under copper (Cu) perturbation. Copper stress significantly reduced enzymatic activities and microbial biomass carbon (MBC) in soil. Percent reduction in microbial activity of soil due to Cu stress was 74.7% in dehydrogenase activity, 59.9% in MBC, 48.2% in alkaline phosphatase activity and 15.1% in acid phosphatase activity. Soil treated with FYM + charcoal showed highest resistance index for enzymatic activities and MBC. Similarly, the highest resilience index for acid phosphatase activity was observed in soil amended with FYM (0.40), whereas FYM + charcoal-treated soil showed the highest resilience indices for alkaline, dehydrogenase activity and MBC: 0.50, 0.22 and 0.25, respectively. This investigation showed that FYM and charcoal application, either alone or in combination, proved to be better than lime with respect to microbial functional resistance and resilience of acid soil under Cu perturbation.

Responses of Lumbriculus variegatus to activated carbon amendments in uncontaminated sediments.

PubMed

Nybom, Inna; Werner, David; Leppänen, Matti T; Siavalas, George; Christanis, Kimon; Karapanagioti, Hrissi K; Kukkonen, Jussi V K; Akkanen, Jarkko

2012-12-04

Activated carbon (AC) amendment is a recently developed sediment remediation method. The strong hydrophobic organic contaminant sorption efficiency of AC has been shown in several studies, but effects on benthic organisms require more investigation. The AC induced effects on egestion rate, growth and reproduction of Lumbriculus variegatus were studied by applying bituminous coal based AC in three different particle size fractions, namely <63 μm (90%, AC(p)), 63-200 μm (AC(m)) and 1000 μm (AC(g)), to natural uncontaminated (HS) and artificial sediment (AS). Egestion rate, growth and reproduction decreased with increasing AC concentration and finer AC particle fractions, effects being stronger on HS than on AS sediment. Lipid content in AS was reduced already at the lowest AC doses applied (AC(p) and AC(m) 0.05%, AC(g) 0.25%). In addition, hormesis-like response was observed in growth (AS) and reproduction (AS, HS) indicating that AC may disturb organisms even at very low doses. Potential ecological effects need to be further evaluated in an amendment- and site-specific manner.

Biochar, activated carbon, and carbon nanotubes have different effects on fate of (14)C-catechol and microbial community in soil.

PubMed

Shan, Jun; Ji, Rong; Yu, Yongjie; Xie, Zubin; Yan, Xiaoyuan

2015-10-30

This study investigated the effects of biochar, activated carbon (AC)-, and single-walled and multi-walled carbon nanotubes (SWCNTs and MWCNTs) in various concentrations (0, 0.2, 20, and 2,000 mg/kg dry soil) on the fate of (14)C-catechol and microbial community in soil. The results showed that biochar had no effect on the mineralization of (14)C-catechol, whereas AC at all amendment rates and SWCNTs at 2,000 mg/kg significantly reduced mineralization. Particularly, MWCNTs at 0.2 mg/kg significantly stimulated mineralization compared with the control soil. The inhibitory effects of AC and SWCNTs on the mineralization were attributed to the inhibited soil microbial activities and the shifts in microbial communities, as suggested by the reduced microbial biomass C and the separated phylogenetic distance. In contrast, the stimulatory effects of MWCNTs on the mineralization were attributed to the selective stimulation of specific catechol-degraders by MWCNTs at 0.2 mg/kg. Only MWCNTs amendments and AC at 2,000 mg/kg significantly changed the distribution of (14)C residues within the fractions of humic substances. Our findings suggest biochar, AC, SWCNTs and MWCNTs have different effects on the fate of (14)C-catechol and microbial community in soil.

Biochar, activated carbon, and carbon nanotubes have different effects on fate of 14C-catechol and microbial community in soil

PubMed Central

Shan, Jun; Ji, Rong; Yu, Yongjie; Xie, Zubin; Yan, Xiaoyuan

2015-01-01

This study investigated the effects of biochar, activated carbon (AC)-, and single-walled and multi-walled carbon nanotubes (SWCNTs and MWCNTs) in various concentrations (0, 0.2, 20, and 2,000 mg/kg dry soil) on the fate of 14C-catechol and microbial community in soil. The results showed that biochar had no effect on the mineralization of 14C-catechol, whereas AC at all amendment rates and SWCNTs at 2,000 mg/kg significantly reduced mineralization. Particularly, MWCNTs at 0.2 mg/kg significantly stimulated mineralization compared with the control soil. The inhibitory effects of AC and SWCNTs on the mineralization were attributed to the inhibited soil microbial activities and the shifts in microbial communities, as suggested by the reduced microbial biomass C and the separated phylogenetic distance. In contrast, the stimulatory effects of MWCNTs on the mineralization were attributed to the selective stimulation of specific catechol-degraders by MWCNTs at 0.2 mg/kg. Only MWCNTs amendments and AC at 2,000 mg/kg significantly changed the distribution of 14C residues within the fractions of humic substances. Our findings suggest biochar, AC, SWCNTs and MWCNTs have different effects on the fate of 14C-catechol and microbial community in soil. PMID:26515132

Relative contribution of maize and external manure amendment to soil carbon sequestration in a long-term intensive maize cropping system

PubMed Central

Zhang, Wenju; Liu, Kailou; Wang, Jinzhou; Shao, Xingfang; Xu, Minggang; Li, Jianwei; Wang, Xiujun; Murphy, Daniel V.

2015-01-01

We aimed to quantify the relative contributions of plant residue and organic manure to soil carbon sequestration. Using a 27-year-long inorganic fertilizer and manure amendment experiment in a maize (Zea mays L.) double-cropping system, we quantified changes in harvestable maize biomass and soil organic carbon stocks (0–20 cm depth) between 1986-2012. By employing natural 13C tracing techniques, we derived the proportional contributions of below-ground crop biomass return (maize-derived carbon) and external manure amendment (manure-derived carbon) to the total soil organic carbon stock. The average retention of maize-derived carbon plus manure-derived carbon during the early period of the trial (up to 11 years) was relatively high (10%) compared to the later period (22 to 27 years, 5.1–6.3%). About 11% of maize-derived carbon was converted to soil organic carbon, which was double the retention of manure-derived carbon (4.4–5.1%). This result emphasized that organic amendments were necessary to a win-win strategy for both SOC sequestration and maize production. PMID:26039186

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.

Soil amendments yield persisting effects on the microbial communities--a 7-year study

USDA-ARS?s Scientific Manuscript database

Soil microbial communities are sensitive to carbon amendments and largely control the decomposition and accumulation of soil organic matter. In this study, we evaluated whether the type of carbon amendment applied to wheat-cropped or fallow soil imparted lasting effects on the microbial community w...

Long-Term Effects of Multiwalled Carbon Nanotubes and Graphene on Microbial Communities in Dry Soil.

PubMed

Ge, Yuan; Priester, John H; Mortimer, Monika; Chang, Chong Hyun; Ji, Zhaoxia; Schimel, Joshua P; Holden, Patricia A

2016-04-05

Little is known about the long-term effects of engineered carbonaceous nanomaterials (ECNMs) on soil microbial communities, especially when compared to possible effects of natural or industrial carbonaceous materials. To address these issues, we exposed dry grassland soil for 1 year to 1 mg g(-1) of either natural nanostructured material (biochar), industrial carbon black, three types of multiwalled carbon nanotubes (MWCNTs), or graphene. Soil microbial biomass was assessed by substrate induced respiration and by extractable DNA. Bacterial and fungal communities were examined by terminal restriction fragment length polymorphism (T-RFLP). Microbial activity was assessed by soil basal respiration. At day 0, there was no treatment effect on soil DNA or T-RFLP profiles, indicating negligible interference between the amended materials and the methods for DNA extraction, quantification, and community analysis. After a 1-year exposure, compared to the no amendment control, some treatments reduced soil DNA (e.g., biochar, all three MWCNT types, and graphene; P < 0.05) and altered bacterial communities (e.g., biochar, carbon black, narrow MWCNTs, and graphene); however, there were no significant differences across the amended treatments. These findings suggest that ECNMs may moderately affect dry soil microbial communities but that the effects are similar to those from natural and industrial carbonaceous materials, even after 1-year exposure.

Competitive interactions between methane- and ammonia-oxidizing bacteria modulate carbon and nitrogen cycling in paddy soil

NASA Astrophysics Data System (ADS)

Zheng, Y.; Huang, R.; Wang, B. Z.; Bodelier, P. L. E.; Jia, Z. J.

2014-06-01

Pure culture studies have demonstrated that methanotrophs and ammonia oxidizers can both carry out the oxidation of methane and ammonia. However, the expected interactions resulting from these similarities are poorly understood, especially in complex, natural environments. Using DNA-based stable isotope probing and pyrosequencing of 16S rRNA and functional genes, we report on biogeochemical and molecular evidence for growth stimulation of methanotrophic communities by ammonium fertilization, and that methane modulates nitrogen cycling by competitive inhibition of nitrifying communities in a rice paddy soil. Pairwise comparison between microcosms amended with CH4, CH4+Urea, and Urea indicated that urea fertilization stimulated methane oxidation activity 6-fold during a 19-day incubation period, while ammonia oxidation activity was significantly suppressed in the presence of CH4. Pyrosequencing of the total 16S rRNA genes revealed that urea amendment resulted in rapid growth of Methylosarcina-like MOB, and nitrifying communities appeared to be partially inhibited by methane. High-throughput sequencing of the 13C-labeled DNA further revealed that methane amendment resulted in clear growth of Methylosarcina-related MOB while methane plus urea led to an equal increase in Methylosarcina and Methylobacter-related type Ia MOB, indicating the differential growth requirements of representatives of these genera. An increase in 13C assimilation by microorganisms related to methanol oxidizers clearly indicated carbon transfer from methane oxidation to other soil microbes, which was enhanced by urea addition. The active growth of type Ia methanotrops was significantly stimulated by urea amendment, and the pronounced growth of methanol-oxidizing bacteria occurred in CH4-treated microcosms only upon urea amendment. Methane addition partially inhibited the growth of Nitrosospira and Nitrosomonas in urea-amended microcosms, as well as growth of nitrite-oxidizing bacteria. These results suggest that type I methanotrophs can outcompete type II methane oxidizers in nitrogen-rich environments, rendering the interactions among methane and ammonia oxidizers more complicated than previously appreciated.

Controls and dynamics of biochar decay and soil microbial abundance, carbon use efficiency during long-term biochar-amended soil incubations

USDA-ARS?s Scientific Manuscript database

Biochar addition to soil has been proposed as a management strategy to sequester a recalcitrant form of carbon (C). However, there is growing evidence that biochar can be degraded by soil microbes and modify their abundance, community composition and activity. Yet we lack an understanding of how mic...

Carbon stabilization and microbial growth in acidic mine soils after addition of different amendments for soil reclamation

NASA Astrophysics Data System (ADS)

Zornoza, Raúl; Acosta, Jose; Ángeles Muñoz, María; Martínez-Martínez, Silvia; Faz, Ángel; Bååth, Erland

2016-04-01

The extreme soil conditions in metalliferous mine soils have a negative influence on soil biological activity and therefore on soil carbon estabilization. Therefore, amendments are used to increase organic carbon content and activate microbial communities. In order to elucidate some of the factors controlling soil organic carbon stabilization in reclaimed acidic mine soils and its interrelationship with microbial growth and community structure, we performed an incubation experiment with four amendments: pig slurry (PS), pig manure (PM) and biochar (BC), applied with and without marble waste (MW; CaCO3). Results showed that PM and BC (alone or together with MW) contributed to an important increment in recalcitrant organic C, C/N ratio and aggregate stability. Bacterial and fungal growths were highly dependent on pH and labile organic C. PS supported the highest microbial growth; applied alone it stimulated fungal growth, and applied with MW it stimulated bacterial growth. BC promoted the lowest microbial growth, especially for fungi, with no significant increase in fungal biomass. MW+BC increased bacterial growth up to values similar to PM and MW+PM, suggesting that part of the biochar was degraded, at least in short-term mainly by bacteria rather than fungi. PM, MW+PS and MW+PM supported the highest microbial biomass and a similar community structure, related with the presence of high organic C and high pH, with immobilization of metals and increased soil quality. BC contributed to improved soil structure, increased recalcitrant organic C, and decreased metal mobility, with low stimulation of microbial growth.

Laboratory-scale evaluation of a combined soil amendment for the enhanced biodegradation of propylene glycol-based aircraft de-icing fluids.

PubMed

Libisch, Balázs; French, Helen K; Hartnik, Thomas; Anton, Attila; Biró, Borbála

2012-01-01

A combined soil amendment was tested in microcosm experiments with an aim to enhance the aerobic biodegradation of propylene glycol (PG)-based aircraft de-icing fluids during and following the infiltration of contaminated snowmelt. A key objective under field conditions is to increase degradation of organic pollutants in the surface soil where higher microbial activity and plant rhizosphere effects may contribute to a more efficient biodegradation of PG, compared to subsoil ground layers, where electron acceptors and nutrients are often depleted. Microcosm experiments were set up in Petri dishes using 50 g of soil mixed with appropriate additives. The samples contained an initial de-icing fluid concentration of 10,000 mg/kg soil. A combined amendment using calcium peroxide, activated carbon and 1 x Hoagland solution resulted in significantly higher degradation rates for PG both at 4 and 22 degrees C. Most probable numbers of bacteria capable of utilizing 10,000 mg/kg de-icing fluid as a sole carbon source were about two orders of magnitude higher in the amended soil samples compared to unamended controls at both temperatures. The elevated numbers of such bacteria in surface soil may be a source of cells transported to the subsoil by snowmelt infiltration. The near-surface application of amendments tested here may enhance the growth of plants and plant roots in the contaminated area, as well as microbes to be found at greater depth, and hence increase the degradation of a contaminant plume present in the ground.

Microbial responses to polycyclic aromatic hydrocarbon contamination in temporary river sediments: Experimental insights.

PubMed

Zoppini, Annamaria; Ademollo, Nicoletta; Amalfitano, Stefano; Capri, Silvio; Casella, Patrizia; Fazi, Stefano; Marxsen, Juergen; Patrolecco, Luisa

2016-01-15

Temporary rivers are characterized by dry-wet phases and represent an important water resource in semi-arid regions worldwide. The fate and effect of contaminants have not been firmly established in temporary rivers such as in other aquatic environments. In this study, we assessed the effects of sediment amendment with Polycyclic Aromatic Hydrocarbons (PAHs) on benthic microbial communities. Experimental microcosms containing natural (Control) and amended sediments (2 and 20 mg PAHs kg(-1) were incubated for 28 days. The PAH concentrations in sediments were monitored weekly together with microbial community structural (biomass and phylogenetic composition by TGGE and CARD-FISH) and functional parameters (ATP concentration, community respiration rate, bacterial carbon production rate, extracellular enzyme activities). The concentration of the PAH isomers did not change significantly with the exception of phenanthrene. No changes were observed in the TGGE profiles, whereas the occurrence of Alpha- and Beta-Proteobacteria was significantly affected by the treatments. In the amended sediments, the rates of carbon production were stimulated together with aminopeptidase enzyme activity. The community respiration rates showed values significantly lower than the Control after 1 day from the amendment then recovering the Control values during the incubation. A negative trend between the respiration rates and ATP concentration was observed only in the amended sediments. This result indicates a potential toxic effect on the oxidative phosphorylation processes. The impoverishment of the energetic resources that follows the PAH impact may act as a domino on the flux of energy from prokaryotes to the upper level of the trophic chain, with the potential to alter the temporary river functioning.

Evolution of soil organic matter changes using pyrolysis and metabolic indices: a comparison between organic and mineral fertilization.

PubMed

Marinari, S; Masciandaro, G; Ceccanti, B; Grego, S

2007-09-01

The aim of this study was to evaluate chemical and biochemical changes of organic matter in fertilized (ammonium nitrate) and amended (vermicompost and manure) soils using pyrolysis and metabolic indices. The metabolic potential [dehydrogenase (DH-ase)/water soluble organic carbon (WSOC)], the metabolic quotient (qCO2) and the microbial quotient (Cmic:Corg) were calculated as indices of soil organic matter evolution. Pyrolysis-gas chromatography (Py-GC) was used to study structural changes in the organic matter. Carbon forms and microbial biomass have been measured by dichromate oxidation and fumigation-extraction methods, respectively. Dehydrogenase activity has been tested using INT (p-Iodonitrotetrazolium violet) as substrate. The results showed that organic amendment increased soil microbial biomass and its activity which were strictly related to pyrolytic mineralization and humification indices (N/O, B/E3). Mineral fertilization caused a greater alteration of native soil organic matter than the organic amendments, in that a high release of WSOC and relatively large amounts of aliphatic pyrolytic products, were observed. Therefore, the pyrolysis and metabolic indices provided similar and complementary information on soil organic matter changes after mineral and organic fertilization.

Amended Ballistic Sand Studies to Provide Low Maintenance Lead Containment at Active Small Arms Firing Range Systems

DTIC Science & Technology

2007-09-01

Pb2+. Under alkaline conditions, elemental lead will oxidize under most circumstances to form a lead hydroxide complex Pb(OH)53-. Lead that exists...lead hydroxide [Pb(OH)2], lead carbonate [PbCO3, cerrusite], or basic lead carbonate [Pb3(OH)2 (CO3)2, hydrocerrusite]. The overall lead solubility...in a natural system is fundamentally determined by the concentrations of the anions in solution (e.g., the hydroxide and carbonate ions) and by the

75 FR 7631 - Notice of Environmental Assessment Related to the Issuance of a License Amendment to Byproduct...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-22

... unsealed Hydrogen-3 and Carbon-14 for use during in-vitro research labeling activities. However, through... Hydrogen-3 was the only licensed material used in the facility. The licensee permanently ceased licensed... licensee's historical review of past research activities determined that Hydrogen-3 was the only...

Type and amount of organic amendments affect enhanced biogenic methane production from coal and microbial community structure

USGS Publications Warehouse

Davis, Katherine J.; Lu, Shipeng; Barnhart, Elliott P.; Parker, Albert E.; Fields, Matthew W.; Gerlach, Robin

2018-01-01

Slow rates of coal-to-methane conversion limit biogenic methane production from coalbeds. This study demonstrates that rates of coal-to-methane conversion can be increased by the addition of small amounts of organic amendments. Algae, cyanobacteria, yeast cells, and granulated yeast extract were tested at two concentrations (0.1 and 0.5 g/L), and similar increases in total methane produced and methane production rates were observed for all amendments at a given concentration. In 0.1 g/L amended systems, the amount of carbon converted to methane minus the amount produced in coal only systems exceeded the amount of carbon added in the form of amendment, suggesting enhanced coal-to-methane conversion through amendment addition. The amount of methane produced in the 0.5 g/L amended systems did not exceed the amount of carbon added. While the archaeal communities did not vary significantly, the bacterial populations appeared to be strongly influenced by the presence of coal when 0.1 g/L of amendment was added; at an amendment concentration of 0.5 g/L the bacterial community composition appeared to be affected most strongly by the amendment type. Overall, the results suggest that small amounts of amendment are not only sufficient but possibly advantageous if faster in situcoal-to-methane production is to be promoted.

Carbon Limitation Induces ςS-Dependent Gene Expression in Pseudomonas fluorescens in Soil

PubMed Central

Koch, Birgit; Worm, Jakob; Jensen, Linda E.; Højberg, Ole; Nybroe, Ole

2001-01-01

Recent studies employing reporter gene technology indicate that the availabilities of the major nutrients nitrogen, phosphate, and iron to Pseudomonas are not severely limited in bulk soil. Indirect evidence has pointed to carbon limitation as a severe nutritional stress in this environment. We show that a plasmid (pGM115)-borne transcriptional fusion between the ςS-dependent Escherichia coli promoter Pfic and lacZ functions as a reliable reporter for carbon availability in Pseudomonas fluorescens. When P. fluorescens strain DF57(pGM115) was introduced into bulk soil, carbon-limiting conditions were indicated by citrate-repressible induction of β-galactosidase activity. To address carbon availability at the single-cell level, we developed an immunofluorescence double-staining procedure for individual DF57 cells expressing β-galactosidase from Pfic. Changes in cell size and expression of β-galactosidase were analyzed by flow cytometry. Cells extracted from soil microcosms reduced their size less than carbon-starved cells in pure culture and showed an increased tendency to aggregate. The single-cell analysis revealed that for cells residing in soil, the expression of β-galactosidase became heterogeneous and only a DF57 subpopulation appeared to be carbon limited. In soil amended with barley straw, limited nitrogen availability has been determined by use of the bioluminescent reporter strain P. fluorescens DF57-N3. We used strain DF57-N3(pGM115) as a double reporter for carbon and nitrogen limitation that allowed us to study the dynamics of carbon and nitrogen availabilities in more detail. In straw-amended soil β-galactosidase activity remained low, while nitrogen limitation-dependent bioluminescence appeared after a few days. Hence, nitrogen became limited under conditions where carbon resources were not completely exhausted. PMID:11472905

Alleviation of environmental risks associated with severely contaminated mine tailings using amendments: Modeling of trace element speciation, solubility, and plant accumulation.

PubMed

Pardo, Tania; Bes, Cleménce; Bernal, Maria Pilar; Clemente, Rafael

2016-11-01

Tailings are considered one of the most relevant sources of contamination associated with mining activities. Phytostabilization of mine spoils may need the application of the adequate combination of amendments to facilitate plant establishment and reduce their environmental impact. Two pot experiments were set up to assess the capability of 2 inorganic materials (calcium carbonate and a red mud derivate, ViroBind TM ), alone or in combination with organic amendments, for the stabilization of highly acidic trace element-contaminated mine tailings using Atriplex halimus. The effects of the treatments on tailings and porewater physico-chemical properties and trace-element accumulation by the plants, as well as the processes governing trace elements speciation and solubility in soil solution and their bioavailability were modeled. The application of the amendments increased tailings pH and decreased (>99%) trace elements solubility in porewater, but also changed the speciation of soluble Cd, Cu, and Pb. All the treatments made A. halimus growth in the tailings possible; organic amendments increased plant biomass and nutritional status, and reduced trace-element accumulation in the plants. Tailings amendments modified trace-element speciation in porewater (favoring the formation of chlorides and/or organo-metallic forms) and their solubility and plant uptake, which were found to be mainly governed by tailing/porewater pH, electrical conductivity, and organic carbon content, as well as soluble/available trace-element concentrations. Environ Toxicol Chem 2016;35:2874-2884. © 2016 SETAC. © 2016 SETAC.

Effects of biochar on dechlorination of hexachlorobenzene and the bacterial community in paddy soil.

PubMed

Song, Yang; Bian, Yongrong; Wang, Fang; Herzberger, Anna; Yang, Xinglun; Gu, Chenggang; Jiang, Xin

2017-11-01

Anaerobic reductive dechlorination is an important degradation pathway for chlorinated organic contaminants in paddy soil. This study investigated the effects of amending paddy soil with wheat straw biochar on both the dechlorination of hexachlorobenzene (HCB), a typical highly chlorinated contaminant, and on the structure of soil bacteria communities. Soil amendment of 0.1% biochar did not significantly affect the dechlorination of HCB in the soil. However, biochar amendment at higher application levels (5%) stimulated the dechlorination of HCB in the first month of anaerobic incubation and inhibited the dechlorination of HCB after that period. The stimulation effect may be ascribed to the graphite carbon and carbon-centered persistent radicals, which are redox active, in biochar. The inhibiting effect could be partly ascribed to the reduced bioavailability of HCB in biochar-amended soils. High-throughput sequencing revealed that the amendment of biochar changed the soil bacterial community structure but not the bacterial abundances and diversities. The relative abundance of Dehalococcoidaceae in the tested soils showed a significant relationship with the dechlorination percentages of HCB, indicating that Dehalococcoidaceae may be the main HCB-dechlorinating bacteria in the studied paddy soil. The results indicated that low application levels of biochar did not affect the dechlorination of HCB in the paddy soil, while high application levels of biochar mainly inhibited the dechlorination of HCB due to the reduced bioavailability of HCB and the reduced abundances of certain dechlorinating bacteria in the biochar-amended paddy soil. Copyright © 2017 Elsevier Ltd. All rights reserved.

Addition of organic amendments contributes to C sequestration in trace element contaminated soils.

NASA Astrophysics Data System (ADS)

del Mar Montiel Rozas, María; Panettier, Marco; Madejón Rodríguez, Paula; Madejón Rodríguez, Engracia

2015-04-01

Nowadays, the study of global C cycle and the different natural sinks of C have become especially important in a climate change context. Fluxes of C have been modified by anthropogenic activities and, presently, the global objective is the decrease of net CO2 emission. For this purpose, many studies are being conducted at local level for evaluate different C sequestration strategies. These techniques must be, in addition to safe in the long term, environmentally friendly. Restoration of contaminated and degraded areas is considered as a strategy for SOC sequestration. Our study has been carried out in the Guadiamar Green Corridor (Seville, Spain) affected by the Aznalcóllar mining accident. This accident occurred 16 years ago, due to the failure of the tailing dam which contained 4-5 million m3 of toxic tailings (slurry and acid water).The affected soils had a layer of toxic sludge containing heavy metals as As, Cd, Cu, Pb and Zn. Restoration techniques began to be applied just after the accident, including the removal of the toxic sludge and a variable layer of topsoil (10-30 cm) from the surface. In a second phase, in a specific area (experimental area) of the Green Corridor the addition of organic amendments (Biosolid compost (BC) and Leonardite (LE), a low grade coal rich in humic acids) was carried out to increase pH, organic matter and fertility in a soil which lost its richest layer during the clean-up operation. In our experimental area, half of the plots (A) received amendments for four years (2002, 2003, 2006 and 2007) whereas the other half (B) received amendments only for two years (2002-2003). To compare, plots without amendments were also established. Net balance of C was carried out using values of Water Soluble Carbon (WSC) and Total Organic Carbon (TOC) for three years (2012, 2013 and 2015). To eliminate artificial changes carried out in the plots, amendment addition and withdrawal of biomass were taken into account to calculate balance of kg TOC ha ¯¹. Thus, results revealed the effect of amendments. Values of net balance show an increase in C sequestered in amended plots. The retention of carbon in soluble and total forms was reflected in the increase in time. According to the results, application of leonardite (a more stabilized amendment) seems to entail a greater retention of carbon in soil than in the case of biosolid compost. Restoration strategies have multiple benefits for the ecosystem. In our case, the use of organic amendments decreased trace element toxicity, improved soil structure and microbial communities, and contribute to retain C in terrestrial ecosystems.

Impacts of Activated Carbon Amendment on Hg Methylation, Demethylation and Microbial Activity in Marsh Soils

NASA Astrophysics Data System (ADS)

Gilmour, C. C.; Ghosh, U.; Santillan, E. F. U.; Soren, A.; Bell, J. T.; Butera, D.; McBurney, A. W.; Brown, S.; Henry, E.; Vlassopoulos, D.

2015-12-01

In-situ sorbent amendments are a low-impact approach for remediation of contaminants in sediments, particular in habitats like wetlands that provide important ecosystem services. Laboratory microcosm trials (Gilmour et al. 2013) and early field trials show that activated carbon (AC) can effectively increase partitioning of both inorganic Hg and methylmercury to the solid phase. Sediment-water partitioning can serve as a proxy for Hg and MeHg bioavailability in soils. One consideration in using AC in remediation is its potential impact on organisms. For mercury, a critical consideration is the potential impact on net MeHg accumulation and bioavailability. In this study, we specifically evaluated the impact of AC on rates of methylmercury production and degradation, and on overall microbial activity, in 4 different Hg-contaminated salt marsh soils. The study was done over 28 days in anaerobic, sulfate-reducing slurries. A double label of enriched mercury isotopes (Me199Hg and inorganic 201Hg) was used to separately follow de novo Me201Hg production and Me199Hg degradation. AC amendments decreased both methylation and demethylation rate constants relative to un-amended controls, but the impact on demethylation was stronger. The addition of 5% (dry weight) regenerated AC to soil slurries drove demethylation rate constants to nearly zero; i.e. MeHg sorption to AC almost totally blocked its degradation. The net impact was increased solid phase MeHg concentrations in some of the soil slurries with the highest methylation rate constants. However, the net impact of AC amendments was to increase MeHg (and inorganic Hg) partitioning to the soil phase and decrease concentrations in the aqueous phase. AC significantly decreased aqueous phase inorganic Hg and MeHg concentrations after 28 days. Overall, the efficacy of AC in reducing aqueous MeHg was highest in the soils with the highest MeHg concentrations. The AC addition did not significantly impact microbial activity, as assessed by CO2 production and sulfate depletion, in two of the four soils, but resulted in a up to a 40% decrease in two other soils. AC amendment has little effect on slurry pH, but decreased aqueous Fe, sulfide and DOC concentrations.

Changes in soil microbial functional diversity and biochemical characteristics of tree peony with amendment of sewage sludge compost.

PubMed

Huang, Xiangdong; Xue, Dong; Xue, Lian

2015-08-01

A greenhouse experiment was conducted to investigate the impact of sewage sludge compost application on functional diversity of soil microbial communities, based on carbon source utilization, and biochemical characteristics of tree peony (Paeonia suffruticosa). Functional diversity was estimated with incubations in Biolog EcoPlates and well color development was used as the functional trait for carbon source utilization. The average well color development and Shannon index based on the carbon source utilization pattern in Biolog EcoPlates significantly increased with the increasing sludge compost application in the range of 0-45%, with a decreasing trend above 45%. Principal component analysis of carbon source utilization pattern showed that sludge compost application stimulated the utilization rate of D-cellobiose and α-D-lactose, while the utilization rate of β-methyl-D-glucoside, L-asparagine, L-serine, α-cyclodextrin, γ-hydroxybutyric acid, and itaconic acid gradually increased up to a sludge compost amendment dosage of 45% and then decreased above 45%. The chlorophyll content, antioxidase (superoxide dismutase, catalase, and peroxidase) activities, plant height, flower diameter, and flower numbers per plant of tree peony increased significantly with sludge compost dosage, reaching a peak value at 45 %, and then decreased with the exception that activity of superoxide dismutase and catalase did not vary significantly.

Effect of biochar amendment on compost organic matter composition following aerobic composting of manure.

PubMed

Hagemann, Nikolas; Subdiaga, Edisson; Orsetti, Silvia; de la Rosa, José María; Knicker, Heike; Schmidt, Hans-Peter; Kappler, Andreas; Behrens, Sebastian

2018-02-01

Biochar, a material defined as charred organic matter applied in agriculture, is suggested as a beneficial additive and bulking agent in composting. Biochar addition to the composting feedstock was shown to reduce greenhouse gas emissions and nutrient leaching during the composting process, and to result in a fertilizer and plant growth medium that is superior to non-amended composts. However, the impact of biochar on the quality and carbon speciation of the organic matter in bulk compost has so far not been the focus of systematic analyses, although these parameters are key to determine the long-term stability and carbon sequestration potential of biochar-amended composts in soil. In this study, we used different spectroscopic techniques to compare the organic carbon speciation of manure compost amended with three different biochars. A non-biochar-amended compost served as control. Based on Fourier-transformed infrared (FTIR) and 13 C nuclear magnetic resonance (NMR) spectroscopy we did not observe any differences in carbon speciation of the bulk compost independent of biochar type, despite a change in the FTIR absorbance ratio 2925cm -1 /1034cm -1 , that is suggested as an indicator for compost maturity. Specific UV absorbance (SUVA) and emission-excitation matrixes (EEM) revealed minor differences in the extractable carbon fractions, which only accounted for ~2-3% of total organic carbon. Increased total organic carbon content of biochar-amended composts was only due to the addition of biochar-C and not enhanced preservation of compost feedstock-C. Our results suggest that biochars do not alter the carbon speciation in compost organic matter under conditions optimized for aerobic decomposition of compost feedstock. Considering the effects of biochar on compost nutrient retention, mitigation of greenhouse gas emissions and carbon sequestration, biochar addition during aerobic composting of manure might be an attractive strategy to produce a sustainable, slow release fertilizer. Copyright © 2017 Elsevier B.V. All rights reserved.

CONTROLLING ORGANICS WITH GAC: A COST AND PERFORMANCE ANALYSIS

EPA Science Inventory

The amendments to the US Safe Drinking Water Act require extensive evaluation of the feasibility or removing organic compounds using granular activated carbon (GAC). To meet deadlines for this technology evaluation, the US Environmental Prtotection Agency has combined the use of ...

Modeling polychlorinated biphenyl mass transfer after amendment of contaminated sediment with activated carbon.

PubMed

Werner, David; Ghosh, Upal; Luthy, Richard G

2006-07-01

The sorption kinetics and concentration of polychlorinated biphenyls (PCBs) in historically polluted sediment is modeled to assess a remediation strategy based on in situ PCB sequestration by mixing with activated carbon (AC). We extend our evaluation of a model based on intraparticle diffusion by including a biomimetic semipermeable membrane device (SPMD) and a first-order degradation rate for the aqueous phase. The model predictions are compared with the previously reported experimental PCB concentrations in the bulk water phase and in SPMDs. The simulated scenarios comprise a marine and a freshwater sediment, four PCB congeners, two AC grain sizes, four doses of AC, and comparison with laboratory experiments for up to 540 days of AC amendment slowly mixed with sediment. The model qualitatively reproduces the observed shifts in the PCB distribution during repartitioning after AC amendment but systematically overestimates the overall effect of the treatment in reducing aqueous and SPMD concentrations of PCBs by a factor of 2-6. For our AC application in sediment, competitive sorption of the various solutes apparently requires a reduction by a factor of 16 of the literature values for the AC-water partitioning coefficient measured in pure aqueous systems. With this correction, model results and measurements agree within a factor of 3. We also discuss the impact of the nonlinearity of the AC sorption isotherm and first-order degradation in the aqueous phase. Regular mixing of the sediment accelerates the benefit of the proposed amendment substantially. But according to our scenario, after AC amendment is homogeneously mixed into the sediment and then left undisturbed, aqueous PCB concentrations tend toward the same reduction after approximately 5 or more years.

Exploration of biodegradation mechanisms of black carbon-bound nonylphenol in black carbon-amended sediment.

PubMed

Cheng, Guanghuan; Sun, Mingyang; Ge, Xinlei; Xu, Xinhua; Lin, Qi; Lou, Liping

2017-12-01

The present study aimed to investigate biodegradation mechanisms of black carbon (BC)-bound contaminants in BC-amended sediment when BC was applied to control organic pollution. The single-point Tenax desorption technique was applied to track the species changes of nonylphenol (NP) during biodegradation process in the rice straw carbon (RC)-amended sediment. And the correlation between the biodegradation and desorption of NP was analyzed. Results showed that microorganisms firstly degraded the rapid-desorbing NP (6 h Tenax desorption) in RC-amended sediment. The biodegradation facilitated the desorption of slow-desorbing NP, which was subsequently degraded as well (192 h Tenax desorption). Notably, the final amount of NP degradation was greater than that of NP desorption, indicating that absorbed NP by RC amendment can be degraded by microorganisms. Finally, the residual NP amount in RC-amended sediment was decided by RC content and its physicochemical property. Moreover, the presence of the biofilm was observed by the confocal laser scanning microscope (CLSM) and scanning electron microscope (SEM) so that microorganisms were able to overcome the mass transfer resistance and directly utilized the absorbed NP. Therefore, single-point Tenax desorption alone may not be an adequate basis for the prediction of the bioaccessibility of contaminants to microorganisms or bioremediation potential in BC-amended sediment. Copyright © 2017. Published by Elsevier Ltd.

Amendments and mulches improve the biological quality of soils degraded by mining activities in SE Spain

NASA Astrophysics Data System (ADS)

Luna Ramos, Lourdes; Miralles Mellado, Isabel; Hernández Fernández, María Teresa; García Izquierdo, Carlos; Solé Benet, Albert

2014-05-01

Mining and quarrying activities generate negative visual impacts in the landscape and a loss of environmental quality. Substrate properties at the end of mining are in general not suitable for plant growth, even native ones. In an experimental soil restoration in limestone quarries from Sierra de Gádor (Almería), SE Spain, the effect of organic amendment (sewage sludge, compost from the organic fraction of domestic waste or non-amendment) combined or not with two different kind of mulches (fine gravel, chopped forest residue) was tested by triplicate in 5 x 5 m plots with the aim to improve soil/substrate properties and to reduce evaporation and erosion. In each experimental plot 75 native plants (Stipa tenacissima, Anthyllis terniflora and Anthyllis cytisoides) were planted. Effects of adding organic amendments and mulches on some soil microbiological and biochemical parameters (microbial biomass carbon, basal respiration and different enzymatic activities, such as dehydrogenase, phosphatase, β-glucosidase and urease) were analyzed 5 years after the start of the experiment. Vegetation growth was also monitored. The two-way ANOVA, using as factors amendment and mulch, showed a significant positive influence of organic amendments on microbial biomass (Cmic), basal respiration and some enzymatic activities related to the cycles of C and N. The highest values of these parameters were obtained with compost. The influence of the mulch factor and its interactions with the amendment factor on the measured variables did not follow a clear trend with respect the measured parameters. Mulching did not improved significantly (p<0.05) the positive effect of organic amendments on Cmic although Cmic values increased with the incorporation of "forest chopped residue" and decreased with gravel incorporation. In general, both type of mulch decreased or have no effect on the microbial activity detected in the amended soils, with the only exception of the forest chopped residue, which increased phosphatase activity in the compost amended soil. Plant growth was significantly higher in amended soils than in the control, but it is remarkable that the mulch type "forest chopped residue" had a negative effect on vegetation growth. The addition of organic amendments, especially compost from the organic fraction of domestic wastes, is beneficial to restore degraded or man-made soils from quarrying areas because they stimulate microbial growth and activity, resulting in mineralization of nutrients necessary for plants and increasing soil fertility and quality. However, after 5 years the effects of the mulch "forest chopped residue", on the improvement of soil or substrate quality are not clear.

Mapping Microbial Carbon Substrate Utilization Across Permafrost Thaw

NASA Astrophysics Data System (ADS)

Anderson, D.; Rich, V. I.; Hodgkins, S. B.; Tfaily, M.; Chanton, J.

2014-12-01

Permafrost thaw is likely to create a substantial positive feedback to climate warming, as previously frozen carbon becomes bioavailable and is released to the atmosphere. Microbes mediate this release, while also consuming "new" carbon from plant inputs and middle-aged soil carbon pools in the seasonally-thawed active layer overlying permafrost. This carbon consumption releases carbon dioxide (CO2) and methane (CH4), both potent greenhouse gases. To investigate microbial carbon cycling in this changing habitat, we examined how microbial communities' carbon substrate degradation changes along a natural permafrost thaw gradient in Stordalen Mire (68.35°N, 19.05°E), northern Sweden. At this location, intermediate thaw creates Sphagnum moss-dominated bogs, while complete thaw results in Eriophorum sedge-dominated fens. The progression of thaw results in increasing organic matter lability (Hodgkins et al, 2014), shifting microbial community composition (Mondav & Woodcroft et al 2014), and changing carbon gas emissions (McCalley et al, in review). However, the inter-relationship of the first two in producing the third remains unclear. We analyzed microbial carbon substrate utilization in the intermediate-thaw and full-thaw sites by two incubation-based methods. We used Biolog EcoPlates, which contain 31 ecologically relevant carbon substrates and a colorimetric marker of their consumption, and into which we added a soil liquid suspension. In addition, we performed mason-jar incubations of peat with carbon substrate amendments and measured CH4 and CO2 emissions. Preliminary Biolog Ecoplate incubations showed that intermediate-thaw features responded faster and more strongly overall to a wide range of substrates relative to the full-thaw features. Preliminary mason jar incubations showed that acetate amendment elicited the greatest response increase in CH4 production and the second greatest increase in CO2 production relative to the controls, in samples from both habitats. In addition, the lowest CH4 and CO2 production was seen in amendments of sphagnum acid. It is important to understand the carbon substrate utilization occurring at these initial and advanced thaw features to speculate the degree to which various carbon inputs are being metabolized to produce the observed gas emissions.

A critical evaluation of magnetic activated carbon's potential for the remediation of sediment impacted by polycyclic aromatic hydrocarbons.

PubMed

Han, Zhantao; Sani, Badruddeen; Akkanen, Jarkko; Abel, Sebastian; Nybom, Inna; Karapanagioti, Hrissi K; Werner, David

2015-04-09

Addition of activated carbon (AC) or biochar (BC) to sediment to reduce the chemical and biological availability of organic contaminants is a promising in-situ remediation technology. But concerns about leaving the adsorbed pollutants in place motivate research into sorbent recovery methods. This study explores the use of magnetic sorbents. A coal-based magnetic activated carbon (MAC) was identified as the strongest of four AC and BC derived magnetic sorbents for polycyclic aromatic hydrocarbons (PAHs) remediation. An 8.1% MAC amendment (w/w, equal to 5% AC content) was found to be as effective as 5% (w/w) pristine AC in reducing aqueous PAHs within three months by 98%. MAC recovery from sediment after three months was 77%, and incomplete MAC recovery had both, positive and negative effects. A slight rebound of aqueous PAH concentrations was observed following the MAC recovery, but aqueous PAH concentrations then dropped again after six months, likely due to the presence of the 23% unrecovered MAC. On the other hand, the 77% recovery of the 8.1% MAC dose was insufficient to reduce ecotoxic effects of fine grained AC or MAC amendment on the egestion rate, growth and reproduction of the AC sensitive species Lumbriculus variegatus. Copyright © 2014 Elsevier B.V. All rights reserved.

Influence of Three Contrasting Detrital Carbon Sources on Planktonic Bacterial Metabolism in a Mesotrophic Lake.

PubMed

Wehr; Petersen; Findlay

1999-01-01

Abstract Lakes receive organic carbon from a diversity of sources which vary in their contribution to planktonic microbial food webs. We conducted a mesocosm study to test the effects of three different detrital carbon sources (algae, aquatic macrophytes, terrestrial leaves) on several measures of microbial metabolism in a small meso-eutrophic lake (DOC approximately 5 mg/L). Small DOC additions (DeltaC < 1 mg/L) affected bacterial numbers, growth, and pathways of carbon acquisition. Macrophyte and leaf detritus significantly increased TDP and color, but bacterial densities initially (+12 h) were unaffected. After 168 h, densities in systems amended with terrestrial detritus were 60% less than in controls, while production rates in mesocosms with macrophyte detritus were 4-fold greater. Detritus treatments resulted in greater per-cell production rates either through stable cell numbers and greater growth rates (macrophyte-C) or lower densities with stable production rates (terrestrial-C). After only 12 h, rates of leucine aminopeptidase (LAPase) activity were 2.5x greater in macrophyte-C systems than in controls, but LAPase and beta-N-acetylglucosamindase activities in systems amended with terrestrial-C were only 50% of rates in controls. After 168 h, beta-xylosidase rates were significantly greater in communities with terrestrial and phytoplankton detritus. Microbial utilization of >20% of 102 carbon sources tested were affected by at least one detritus addition. Macrophyte-C had positive (6% of substrates) and negative (14%) effects on substrate use; terrestrial detritus had mainly positive effects. An ordination based on carbon-use profiles (+12 h) revealed a cluster of macrophyte-amended communities with greater use of psicose, lactulose, and succinamic acid; controls and algal-detritus systems were more effective in metabolizing two common sugars and cellobiose. After 168 h, communities receiving terrestrial detritus were most tightly clustered, exhibiting greater use of raffinose, pyroglutamic acid, and sebacic acid. Results suggest that pelagic bacterial communities respond to changes in organic carbon source rapidly and by different routes, including shifts in per-cell production rates and variations in degradation of a variety of compounds comprising the DOC pool.

78 FR 286 - Circular Welded Carbon Steel Pipes and Tubes From Turkey; Amended Final Results of Antidumping...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-03

... Pipes and Tubes From Turkey; Amended Final Results of Antidumping Duty Administrative Review; 2010 to... administrative review of the antidumping duty order on circular welded carbon steel pipes and tubes from Turkey... Act). \\1\\ See Circular Welded Carbon Steel Pipes and Tubes from Turkey; Final Results of Antidumping...

Long-term rice cultivation stabilizes soil organic carbon and promotes soil microbial activity in a salt marsh derived soil chronosequence

PubMed Central

Wang, Ping; Liu, Yalong; Li, Lianqing; Cheng, Kun; Zheng, Jufeng; Zhang, Xuhui; Zheng, Jinwei; Joseph, Stephen; Pan, Genxing

2015-01-01

Soil organic carbon (SOC) sequestration with enhanced stable carbon storage has been widely accepted as a very important ecosystem property. Yet, the link between carbon stability and bio-activity for ecosystem functioning with OC accumulation in field soils has not been characterized. We assessed the changes in microbial activity versus carbon stability along a paddy soil chronosequence shifting from salt marsh in East China. We used mean weight diameter, normalized enzyme activity (NEA) and carbon gain from straw amendment for addressing soil aggregation, microbial biochemical activity and potential C sequestration, respectively. In addition, a response ratio was employed to infer the changes in all analyzed parameters with prolonged rice cultivation. While stable carbon pools varied with total SOC accumulation, soil respiration and both bacterial and fungal diversity were relatively constant in the rice soils. Bacterial abundance and NEA were positively but highly correlated to total SOC accumulation, indicating an enhanced bio-activity with carbon stabilization. This could be linked to an enhancement of particulate organic carbon pool due to physical protection with enhanced soil aggregation in the rice soils under long-term rice cultivation. However, the mechanism underpinning these changes should be explored in future studies in rice soils where dynamic redox conditions exist. PMID:26503629

Long-term rice cultivation stabilizes soil organic carbon and promotes soil microbial activity in a salt marsh derived soil chronosequence

NASA Astrophysics Data System (ADS)

Wang, Ping; Liu, Yalong; Li, Lianqing; Cheng, Kun; Zheng, Jufeng; Zhang, Xuhui; Zheng, Jinwei; Joseph, Stephen; Pan, Genxing

2015-10-01

Soil organic carbon (SOC) sequestration with enhanced stable carbon storage has been widely accepted as a very important ecosystem property. Yet, the link between carbon stability and bio-activity for ecosystem functioning with OC accumulation in field soils has not been characterized. We assessed the changes in microbial activity versus carbon stability along a paddy soil chronosequence shifting from salt marsh in East China. We used mean weight diameter, normalized enzyme activity (NEA) and carbon gain from straw amendment for addressing soil aggregation, microbial biochemical activity and potential C sequestration, respectively. In addition, a response ratio was employed to infer the changes in all analyzed parameters with prolonged rice cultivation. While stable carbon pools varied with total SOC accumulation, soil respiration and both bacterial and fungal diversity were relatively constant in the rice soils. Bacterial abundance and NEA were positively but highly correlated to total SOC accumulation, indicating an enhanced bio-activity with carbon stabilization. This could be linked to an enhancement of particulate organic carbon pool due to physical protection with enhanced soil aggregation in the rice soils under long-term rice cultivation. However, the mechanism underpinning these changes should be explored in future studies in rice soils where dynamic redox conditions exist.

Long-term rice cultivation stabilizes soil organic carbon and promotes soil microbial activity in a salt marsh derived soil chronosequence.

PubMed

Wang, Ping; Liu, Yalong; Li, Lianqing; Cheng, Kun; Zheng, Jufeng; Zhang, Xuhui; Zheng, Jinwei; Joseph, Stephen; Pan, Genxing

2015-10-27

Soil organic carbon (SOC) sequestration with enhanced stable carbon storage has been widely accepted as a very important ecosystem property. Yet, the link between carbon stability and bio-activity for ecosystem functioning with OC accumulation in field soils has not been characterized. We assessed the changes in microbial activity versus carbon stability along a paddy soil chronosequence shifting from salt marsh in East China. We used mean weight diameter, normalized enzyme activity (NEA) and carbon gain from straw amendment for addressing soil aggregation, microbial biochemical activity and potential C sequestration, respectively. In addition, a response ratio was employed to infer the changes in all analyzed parameters with prolonged rice cultivation. While stable carbon pools varied with total SOC accumulation, soil respiration and both bacterial and fungal diversity were relatively constant in the rice soils. Bacterial abundance and NEA were positively but highly correlated to total SOC accumulation, indicating an enhanced bio-activity with carbon stabilization. This could be linked to an enhancement of particulate organic carbon pool due to physical protection with enhanced soil aggregation in the rice soils under long-term rice cultivation. However, the mechanism underpinning these changes should be explored in future studies in rice soils where dynamic redox conditions exist.

Effects of Carbon in Flooded Paddy Soils: Implications for Microbial Activity and Arsenic Mobilization

NASA Astrophysics Data System (ADS)

Avancha, S.; Boye, K.

2014-12-01

In the Mekong delta in Cambodia, naturally occurring arsenic (originating from erosion in the Himalaya Mountains) in paddy soils is mobilized during the seasonal flooding. As a consequence, rice grown on the flooded soils may take up arsenic and expose people eating the rice to this carcinogenic substance. Microbial activity will enhance or decrease the mobilization of arsenic depending on their metabolic pathways. Among the microbes naturally residing in the soil are denitrifying bacteria, sulfate reducers, metal reducers (Fe, Mn), arsenic reducers, methanogens, and fermenters, whose activity varies based on the presence of oxygen. The purpose of the experiment was to assess how different amendments affect the microbial activity and the arsenic mobilization during the transition from aerobic to anaerobic metabolism after flooding of naturally contaminated Cambodian soil. In a batch experiment, we investigated how the relative metabolic rate of naturally occurring microbes could vary with different types of organic carbon. The experiment was designed to measure the effects of various sources of carbon (dried rice straw, charred rice straw, manure, and glucose) on the microbial activity and arsenic release in an arsenic-contaminated paddy soil from Cambodia under flooded conditions. All amendments were added based on the carbon content in order to add 0.036 g of carbon per vial. The soil was flooded with a 10mM TRIS buffer solution at pH 7.04 in airtight 25mL serum vials and kept at 25 °C. We prepared 14 replicates per treatment to sample both gas and solution. On each sampling point, the solution replicates were sampled destructively. The gas replicates continued on and were sampled for both gas and solution on the final day of the experiment. We measured pH, total arsenic, methane, carbon dioxide, and nitrous oxide at 8 hours, 1.5 days, 3.33 days, and 6.33 days from the start of the experiment.

Biodynamic modeling of PCB uptake by Macoma balthica and Corbicula fluminea from sediment amended with activated carbon

USGS Publications Warehouse

McLeod, Pamela B.; Luoma, S.N.; Luthy, R.G.

2008-01-01

Activated carbon amendment was assessed in the laboratory as a remediation strategy for freshwater sediment contaminated with polychlorinated biphenyls (PCBs) from the Grasse River (near Massena, NY). Three end points were evaluated: aqueous equilibrium PCB concentration, uptake into semipermeable membrane devices (SPMDs), and 28-day bioaccumulation in the clam Corbicula fluminea. PCB uptake by water, SPMDs, and clams followed similar trends, with reductions increasing as a function of carbon dose. Average percent reductions in clam tissue PCBs were 67, 86, and 95% for activated carbon doses of 0.7, 1.3, and 2.5% dry wt, respectively. A biodynamic model that incorporates sediment geochemistry and dietary and aqueous uptake routes was found to agree well with observed uptake by C. fluminea in our laboratory test systems. Results from this study were compared to 28-day bioaccumulation experiments involving PCB-contaminated sediment from Hunters Point Naval Shipyard (San Francisco Bay, CA) and the clam Macoma balthica. Due to differences in feeding strategy, M. balthica deposit-feeds whereas C. fluminea filter-feeds, the relative importance of the aqueous uptake route is predicted to be much higher for C. fluminea than for M. balthica. Whereas M. balthica takes up approximately 90% of its body burden through sediment ingestion, C. fluminea only accumulates approximately 45% via this route. In both cases, results strongly suggest that it is the mass transfer of PCBs from native sediment to added carbon particles, not merely reductions in aqueous PCB concentrations, that effectively reduces PCB bioavailability and uptake by sediment-dwelling organisms. ?? 2008 American Chemical Society.

Measuring and Modeling Organochlorine Pesticide Response to Activated Carbon Amendment in Tidal Sediment Mesocosms.

PubMed

Thompson, Jay M; Hsieh, Ching-Hong; Hoelen, Thomas P; Weston, Donald P; Luthy, Richard G

2016-05-03

Activated carbon (AC) sediment amendment for hydrophobic organic contaminants (HOCs) is attracting increasing regulatory and industrial interest. However, mechanistic and well-vetted models are needed. Here, we conduct an 18 month field mesocosm trial at a site containing dichlorodiphenyltrichloroethane (DDT) and chlordane. Different AC applications were applied and, for the first time, a recently published mass transfer model was field tested under varying experimental conditions. AC treatment was effective in reducing DDT and chlordane concentration in polyethylene (PE) samplers, and contaminant extractability by Arenicola brasiliensis digestive fluids. A substantial AC particle size effect was observed. For example, chlordane concentration in PE was reduced by 93% 6 months post-treatment in the powdered AC (PAC) mesocosm, compared with 71% in the granular AC (GAC) mesocosm. Extractability of sediment-associated DDT and chlordane by A. brasiliensis digestive fluids was reduced by at least a factor of 10 in all AC treatments. The model reproduced the relative effects of varying experimental conditions (particle size, dose, mixing time) on concentrations in polyethylene passive samplers well, in most cases within 25% of experimental observations. Although uncertainties such as the effect of long-term AC fouling by organic matter remain, the study findings support the use of the model to assess long-term implications of AC amendment.

Long-term monitoring and modeling of the mass transfer of polychlorinated biphenyls in sediment following pilot-scale in-situ amendment with activated carbon.

PubMed

Cho, Yeo-Myoung; Werner, David; Choi, Yongju; Luthy, Richard G

2012-03-15

The results of five years of post-treatment monitoring following in-situ activated carbon (AC) placement for stabilization of polychlorinated biphenyls (PCBs) at an inter-tidal mudflat adjacent to Hunters Point Shipyard, San Francisco Bay, CA, USA are reported in this paper. After five years, AC levels of the sediment cores were comparable to those at earlier sampling times. Passive sampler uptake validated the benefit of the AC amendment with a strong local sorbent dose-response relationship. The PCB uptakes in passive samplers decreased up to 73% with a 3.7 dry wt.% AC dose after five years, confirming the temporal enhancement of the amendment benefit from a 19% reduction with a 4.4% dose observed within one month. The long-term effectiveness of AC, the local AC dose response, the impact of fouling by NOM, the spatial heterogeneity of AC incorporation, and the effects of advective sediment pore-water movement are discussed with the aid of a PCB mass transfer model. Modeling and experimental results indicated that the homogeneous incorporation of AC in the sediment will significantly accelerate the benefit of the treatment. Copyright © 2011 Elsevier B.V. All rights reserved.

Influence of activated carbon amendment on the accumulation and elimination of PCBs in the earthworm Eisenia fetida.

PubMed

Paul, Piuly; Ghosh, Upal

2011-12-01

In this study we investigated the use of activated carbon (AC) as a soil amendment for reducing bioavailability of polychlorinated biphenyls (PCBs) to the earthworm Eisenia fetida. Artificial soil was contaminated with PCBs and used in bioaccumulation experiments fresh or after aging for 19 months. PCB bioaccumulation in earthworms was reduced by 68% when AC was placed as a layer without mixing and by 94% when AC was manually mixed into the soil. Aging of the same AC mixed soil for 19 months resulted in an overall reduction of 99% in PCB biouptake. AC-treated aged soil also showed two orders of magnitude lower equilibrium aqueous concentrations of PCBs compared to untreated aged soils. The findings from this study indicate that application of engineered sorbents like AC to PCB impacted soils may greatly reduce PCB uptake at the base of the terrestrial food chain. Copyright © 2011 Elsevier Ltd. All rights reserved.

Abiotic reduction of trifluralin and pendimethalin by sulfides in black-carbon-amended coastal sediments.

PubMed

Gong, Wenwen; Liu, Xinhui; Xia, Shuhua; Liang, Baocui; Zhang, Wei

2016-06-05

Dinitroaniline herbicides such as trifluralin and pendimethalin are persistent bioaccumulative toxins to aquatic organisms. Thus, in-situ remediation of contaminated sediments is desired. This study investigated whether black carbons (BCs), including apple wood charcoal (BC1), rice straw biochar (BC2), and activated carbon (BC3), could facilitate abiotic reduction of trifluralin and pendimethalin by sulfides of environmentally-relevant concentrations in anoxic coastal sediments. The reduction rates of trifluralin and pendimethalin increased substantially with increasing BC dosages in the sediments. This enhancing effect was dependent on BC type with the greatest for BC3 followed by BC1 and BC2, which well correlated with their specific surface area. The pseudo-first order reduction rate constants (kobs) for BC3-amended sediment (2%) were 13- and 14 times the rate constants in the BC-free sediment. The reduction rates increased with increasing temperature from 8 to 25°C in the BC-amended sediment, following the Arrhenius relationship. Finally, through molecular modeling by density functional theory and reaction species identification from mass spectra, molecular pathways of trifluralin and pendimethalin reduction were elucidated. In contrary to the separate sequential reduction of each nitro group to amine group, both nitro groups, first reduced to nitroso, then eventually to amine groups. Copyright © 2016 Elsevier B.V. All rights reserved.

Carbon dynamics in an almond orchard soil amended with raw and treated pig slurry

NASA Astrophysics Data System (ADS)

Domínguez, Sara G.; Zornoza, Raúl; Faz, Ángel

2010-05-01

In SE Spain, intensive farming is very common which supposes the generation of great amounts of pig slurries. These residues cause many storage problems due to their pollution capacity. A good management of them is necessary to avoid damages to the environment. The use of this effluent as fertilizer is a usual practice that in the correct dose is a good amend and important for sustainable development, but in excess can be a risk of polluting and damaging soil, water and crop conditions. Pig slurry is a source of many nutrients and specially rich in organic matter. The main objective of this study is to determine changes in soil organic carbon dynamics resulting from raw and treated slurry amendments applied in different doses. The experimental area is an almond orchard located in Cartagena (SE Spain). The climate of the area is semiarid Mediterranean with mean annual temperature of 18°C and mean annual rainfall of 275 mm. A total of 10 plots (12 m x 30 m) were designed, one of them being the control without fertilizer. Surface soil samples (0-25 cm) were collected in September 2009. Three different treatments were applied, raw slurry, the effluent obtained after solid-liquid separation and solid manure, all of them in three doses being the first one of 170 kg N/ha, (maximum permitted in nitrates directive 91/676/CEE), and the others two and three times the first one. Soil biochemical parameters are rapid indicators of changes in soil quality. According to this, total organic carbon, soil microbial biomass carbon, soluble carbon, and β-glucosidase, β-galactosidase and arylesterase activities were measured in order to assess some soil biochemical conditions and carbon dynamics in terms of the different treatments. As we expected, the use of these organic fertilizers rich in organic matter, had an effect on soil carbon and soil microbial activity resulting in an increase in most of the parameters; total organic carbon and β-galactosidase activity showed the biggest increment comparing to control. No pattern was observed among fertilizer doses, without big differences among them in most properties. We can conclude that the use of pig slurry as organic fertilizer incorporates great amounts of organic matter to the soil in its different forms, including soluble and microorganisms biomass, which has a positive effect encouraging the application of this agricultural management so that soil can act as C sink, in order to mitigate global warming. Thus, this procedure can be included in the strategies to increase the soil carbon sequestration. According to carbon dynamics, doses are not important, without risks of soluble carbon leaching.

CO2 efflux from soil under influence of cadmium and glucose

NASA Astrophysics Data System (ADS)

Gilmullina, Aliia; Galitskaya, Polina; Selivanovskaya, Svetlana

2017-04-01

Soil is the largest pool of organic carbon. Any anthropogenic activity may change the soil organic carbon stock resulting in the atmospheric carbon concentration increase. Organic wastes and sewage sludge are often used for soil fertilization. These amendments often contain not only organic compounds stimulating soil microflora but also toxic compounds e.g. metals inhibiting them. The question about the influence of such amendments on soil carbon stock still remains open. The aim of this study was to evaluate individual glucose and cadmium (Cd) additions and their combined effects on carbon mineralization and microbial community structure in forest soil sampled from different depths (0-20 cm, 20-40 cm and 40-60 cm). We incubated soil samples for 14 days after the addition of: glucose (10000 mg kg-1), Cd (300 mg kg-1) and their mixture. CO2 efflux was measured by CO2 trapping in NaOH, at the 3rd, 7th and 14th days of incubation DNA was extracted from soil samples for assessment of microbial community structure via real-time PCR and Illumina sequencing. Glucose addition induced the increase of soil respiration and fungal-bacterial ratio. However, bacterial alpha-biodiversity decreased as glucose addition caused the dominance of Proteobacteria (0-20 cm, 20-40 cm and 40-60 cm), Actinobacteria (20-40 cm) and Acidobacteria (40-60 cm) phyla. Single Cd addition did not have any effect on parameters studied. In case of simultaneous addition of glucose and Cd, soil respiration and microbial community structure mainly depended more on glucose amendment as compared with metal.

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.

Interactions between organic amendments and phosphate fertilizers modify phosphate sorption processes in an acid soil

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

Sckefe, C.R.; Patti, A.F.; Clune, T.S.

2008-07-15

To determine how organic amendments and phosphate fertilizers interact to modify P sorption processes, three phosphate fertilizers were applied to lignite- and compost-amended acid soil and incubated for either 3 or 26 days. The fertilizers applied were potassium dihydrogen phosphate, triple superphosphate, and diammonium phosphate (DAP). After 3 days of incubation, sorption of all three P sources was decreased in the lignite-amended treatments, whereas P sorption was increased in the compost-amended treatments. Increased incubation time (26 days) resulted in significantly decreased P sorption when DAP was added to lignite-amended treatments. Addition of triple superphosphate increased P sorption in lignite- andmore » compost-amended treatments and decreased solution pH compared with DAP application. In addition to the effect of P source, differences in P sorption between the lignite- and compost-amended treatments were driven by differences in solution chemistry, predominantly solution pH and cation dynamics. Soil amendment and fertilizer addition also increased microbial activity in the incubation systems, as measured by carbon dioxide respiration. It is proposed that the combination of lignite and DAP may contribute to decreased P sorption in acid soils, with the positive effects likely caused by both chemical and biological processes, including the formation of soluble organic-metal complexes.« less

Use of additives to enhance the removal of phenols from water treated with horseradish and hydrogen peroxide.

PubMed

Tonegawa, Masami; Dec, Jerzy; Bollag, Jean-Marc

2003-01-01

Use of additives, such as polyethylene glycol (PEG), selected surfactants, chitosan gel, or activated carbon, has been shown to enhance enzymatic treatment of water polluted with organic compounds. In this study, additives were used to facilitate the removal of 2,4-dichlorophenol (2,4-DCP) from water using minced horseradish (Armoracia rusticana P. Gaertn. et al.) as a carrier of peroxidase activity. The specific objectives of the study were to (i) enhance the pollutant removal activity of minced horseradish by the addition of PEG and other additives (e.g., Tween 20, Triton X-100, and rhamnolipid); (ii) eliminate colored reaction products by the addition of chitosan; and (iii) eliminate color by amending treated water with activated carbon. The disappearance of 2,4-DCP in horseradish-treated water samples amended with PEG or various surfactants (75-90%) was greatly increased over that observed in nonamended samples (29%). The effect of PEG depended on its average molecular weight. As indicated by visible spectrophotometry, enclosing horseradish pieces between two sealed chitosan films completely eliminated colored reaction products; however, the decolorization was accompanied by a reduction in 2,4-DCP removal (from 95 to 60%). On the other hand, commercially available activated carbon completely removed colored reaction products from the treated water without reducing the removal efficiency. Based on the results obtained, it can be concluded that the use of additives may considerably improve the quality of wastewater treated by plant materials.

Main factors controlling microbial community structure, growth and activity after reclamation of a tailing pond with aided phytostabilization

NASA Astrophysics Data System (ADS)

Zornoza, Raúl; Acosta, José A.; Martínez-Martínez, Silvia; Faz, Ángel; Bååth, Erland

2015-04-01

Reclamation on bare tailing ponds has the potential to represent soil genesis in Technosols favoring the understanding of the changes of microbial communities and function. In this study we used phytostabilization aided with calcium carbonate and pig slurry/manure to reclaim an acidic bare tailing pond with the aim of investigating the effect of amending and different species on microbial community structure and function. We sampled after two years of amending and planting: unamended tailing soil (UTS), non-rhizospheric amended tailing soil (ATS), rhizospheric soil from four species, and non-rhizospheric native forest soil (NS), which acted as reference. The application of amendments increased pH up to neutrality, organic carbon (Corg), C/N and aggregate stability, while decreased salinity and heavy metals availability. No effect of rhizosphere was observed on physicochemical properties, metals immobilization and microbial community structure and function. To account for confounding effects due to soil organic matter, microbial properties were expressed per Corg. The high increments in pH and Corg have been the main factors driving changes in microbial community structure and function. Bacterial biomass was higher in UTS, without significant differences among the rest of soils. Fungal biomass followed the trend UTS < ATS = rhizospheric soils < NS. Bacterial growth increased and fungal growth decreased with increasing pH, despite the high availability of metals at low pH. Enzyme activities were lower in UTS, being β-glucosidase and β-glucosaminidase activities highly correlated with bacterial growth. Microbial activities were not correlated with the exchangeable fraction of heavy metals, indicating that microbial function is not strongly affected by these metals, likely due to the efficiency of the reclamation procedure to reduce metals toxicity. Changes in microbial community composition were largely explained by changes in pH, heavy metals availability and Corg, with increments in fungal and actinobacterial proportions with soil amending. Acknowledgements R. Zornoza acknowledges the financial support to Fundación Séneca-Agencia de Ciencia y Tecnología de la Región de Murcia (Spain).

Photodegradation processes in arid ecosystems: controlling factors and potential application in land restoration

NASA Astrophysics Data System (ADS)

Muñoz-Rojas, Miriam; Luna-Ramos, Lourdes; Oyonarte, Cecilio; Sole Benet, Albert

2017-04-01

Water availability plays a fundamental part in controlling biotic processes in arid ecosystems. However, recent evidence suggests that other decisive drivers take part in these processes. Despite low annual rainfall and microbial activity, unexplained high rates of litter decomposition, net nitrogen mineralization, soil enzymatic activity and carbon turnover have been observed in arid ecosystems. These observations have been partly explained by photodegradation, a process that consists of the breakdown of organic matter via solar radiation (UV) and that can increase decomposition rates and lead to changes in the balance of carbon and nutrients between plants, soil and atmosphere. A complete understanding of these mechanisms and its drivers in arid ecosystems remains a critical challenge for the scientific community at the global level. In this research, we conducted a multi-site field experiment to test the effects of photodegradation on decomposition of organic amendments used in ecosystem restoration. The study was carried out during 12 months in two study areas: the Pilbara region in Western Australia (Southern Hemisphere) and the Cabo de Gata Nijar Natural Park, South Spain (Northern Hemisphere). In both sites, four treatments were applied in replicated plots (1x1 m, n=4) that included a control (C) with no soil amendment; organic amendment covering the soil surface (AS); organic amendment incorporated into the soil (AI); and a combination of both techniques, both covering the surface and incorporated into the soil (AS-AI). Different organic amendments (native mulch versus compost) and soil substrates were used at each site according to local practices, but in both sites these were applied to increase soil organic matter up to 2%. At the two locations, a radiometer and a logger with a soil temperature and soil moisture probe were installed to monitor UV radiation and soil conditions for the duration of the trial. Soil microbial activity, soil CO2 efflux, and the organic matter fractions (including total OC and hydro-soluble C) were measured repeatedly during the experiment. At the end of the experiment, levels of the soluble fraction of C, soil CO2 efflux and soil microbial activity were significantly (p< 0.05) higher in those plots amended in the surface in both sites. These increases in the surface reflect a fast C decomposing process that can be directly related to UV radiation, evidencing the critical role of photodegradation on the decomposition of the organic matter. These processes can be critical at global scales as they can contribute to forcing biogechemical cycles; however, responses will vary depending on the type of the substrate and organic amendment.

Immobilisation of Cu, Pb and Zn in Scrap Metal Yard Soil Using Selected Waste Materials.

PubMed

Kamari, A; Putra, W P; Yusoff, S N M; Ishak, C F; Hashim, N; Mohamed, A; Isa, I M; Bakar, S A

2015-12-01

Immobilisation of heavy metals in a 30-year old active scrap metal yard soil using three waste materials, namely coconut tree sawdust (CTS), sugarcane bagasse (SB) and eggshell (ES) was investigated. The contaminated soil was amended with amendments at application rates of 0 %, 1 % and 3 % (w/w). The effects of amendments on metal accumulation in water spinach (Ipomoea aquatica) and soil metal bioavailability were studied in a pot experiment. All amendments increased biomass yield and reduced metal accumulation in the plant shoots. The bioconcentration factor and translocation factor values of the metals were in the order of Zn > Cu > Pb. The addition of ES, an alternative source of calcium carbonate (CaCO3), has significantly increased soil pH and resulted in marked reduction in soil metal bioavailability. Therefore, CTS, SB and ES are promising low-cost immobilising agents to restore metal contaminated land.

Enzymatic activities in a semiarid soil amended with different soil treatment: Soil quality improvement

NASA Astrophysics Data System (ADS)

Hueso González, Paloma; Elbl, Jakub; Dvořáčková, Helena; Francisco Martinez Murillo, Juan; Damian Ruiz Sinoga, Jose

2017-04-01

The use of soil quality indicators may be an effective approach to assess the positive effect of the organic amendment as good restoration methods. Relying on the natural fertility of the soil, the most commonly chemical and physical parameters used to evaluate soil quality are depend to the soil biological parameters. The measurement of soil basal respiration and the mineralization of organic matter are commonly accepted as a key indicator for measuring changes to soil quality. Thus, the simultaneous measurement of various enzymes seems to be useful to evaluate soil biochemical activity and related processes. In this line, Dehydrogenase activity is widely used in evaluating the metabolic activity of soil microorganisms and to evaluate the effects caused by the addition of organic amendments. Variations in phosphatase activity, apart from indicating changes in the quantity and quality of soil phosphorated substrates, are also good indicators of soil biological status. This study assesses the effect of five soil amendments as restoration techniques for semiarid Mediterrenean ecosystems. The goal is to interpret the status of biological and chemical parameters in each treatment as soil quality indicators in degraded forests. The main objectives were to: i) analyze the effect of various organic amendments on the enzimatic activity of soil; ii) analyze the effect of the amendments on soil respiration; iii) assess the effect of these parameters on the soil chemical properties which are indicative of soil healthy; and iv) evaluated form the land management point of view which amendment could result a effective method to restore Mediterranean degraded areas. An experimental paired-plot layout was established in southern of Spain (homogeneous slope gradient: 7.5%; aspect: N170). Five amendments were applied in an experimental set of plots: straw mulching; mulch with chipped branches of Aleppo Pine (Pinus halepensis Mill.); TerraCotten hydroabsobent polymers; sewage sludge; sheep manure and; control (without amendment). Five years after the amendment addition, soil from the 12 plots was sampled. Three samples were collected from each plot (36 soil samples in total) from the soil surface, e.g. 0-10 cm, in which most soil transformations occur. Soil indicators analyzed were: i) EC; ii) pH; iii) soil organic C (SOC); iv)total Nitrogen (N); v) Carbon of microbial biomass; vi) Dehydrogenase activity; Phosphatase activity and; vii) basal respiration. According to our results, the straw mulch, pinus mulch and sewage sludge treatments helped to maintain the SOC and N at high levels, five years after the amendment addition and comparing to the control. A similar trend has been registered for the dehydrogenase activity, phosphatase activity and basal respiration. Conversely, regarding to control, when the soils were amended with polymers or manure, no significant differences in soil chemical and biological properties were found. In conclusion, from a land management standpoint, the use of pinus mulch, straw mulch and sewage sludge have been proved as a significant method to increase soil quality on Mediterranean semiarid degraded forests.

Enhanced biochars can match activated carbon performance in sediments with high native bioavailability and low final porewater PCB concentrations.

PubMed

Gomez-Eyles, Jose L; Ghosh, Upal

2018-07-01

A bench scale study was conducted to evaluate the effectiveness of in situ amendments to reduce the bioavailability of pollutants in sediments from a site impacted with polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs) and cadmium. The amendments tested included fine and coarse coal-based activated carbons (AC), an enhanced pinewood derived biochar (EPB), organoclay, and coke dosed at 5% of sediment dry weight. Strong reductions in total PCB porewater concentrations were observed in sediments amended with the fine AC (94.9-99.5%) and EPB (99.6-99.8%). More modest reductions were observed for the coarse AC, organoclay, and coke. Strong reductions in porewater PCB concentrations were reflected in reductions in total PCB bioaccumulation in fresh water oligochaetes for both the fine AC (91.9-96.0%) and EPB (96.1-96.3%). Total PAH porewater concentrations were also greatly reduced by the fine AC (>96.1%) and EPB (>97.8%) treatments. EPB matched or slightly outperformed the fine AC throughout the study, despite sorption data indicating a much stronger affinity of PCBs for the fine AC. Modeling EPB and fine AC effectiveness on other sediments confirmed the high effectiveness of the EPB was due to the very low final porewater concentrations and differences in the native bioavailability between sediments. However, low bulk density and poor settling characteristics make biochars difficult to apply in an aquatic setting. Neither the EPB nor the fine AC amendments were able to significantly reduce Cd bioavailability. Copyright © 2018 Elsevier Ltd. All rights reserved.

Arsenic uptake by lettuce from As-contaminated soil remediated with Pteris vittata and organic amendment.

PubMed

de Oliveira, Letuzia M; Suchismita, Das; Gress, Julia; Rathinasabapathi, Bala; Chen, Yanshan; Ma, Lena Q

2017-06-01

Leaching of inorganic arsenic (As) from chromated copper arsenate (CCA)-treated wood may elevate soil As levels. Thus, an environmental concern arises regarding As accumulation in vegetables grown in these soils. In this study, a greenhouse experiment was conducted to investigate the ability of As-hyperaccumulator P. vittata and organic amendments in reducing As uptake by lettuce (Lactuca sativa) from a soil contaminated from CCA-treated wood (63.9 mg kg -1 As). P. vittata was grown for 150 d in a CCA-contaminated soil amended with biochar, activated carbon or coffee grounds at 1%, followed by lettuce for another 55 d. After harvest, plant biomass and As concentrations in plant and soil were determined. The presence of P. vittata reduced As content in lettuce by 21% from 27.3 to 21.5 mg kg -1 while amendment further reduced As in lettuce by 5.6-18%, with activated C being most effective. Our data showed that both P. vittata and organic amendments were effective in reducing As concentration in lettuce. Though no health-based standard for As in vegetables exists in USA, care should be taken when growing lettuce in contaminated soils. Our data showed that application of organic amendments with P. vittata reduced As hazards in CCA-contaminated soils. Published by Elsevier Ltd.

PERFORMANCE AND COST OF MERCURY EMISSION CONTROL TECHNOLOGY APPLICATIONS ON ELECTRIC UTILITY BOILERS

EPA Science Inventory

The report presents estimates of the performance and cost of powdered activated carbon (PAC) injection-based mercury control technologies and projections of costs for future applications. (NOTE: Under the Clean Air Act Amendments of 1990, the U.S. EPA has to determine whether mer...

Cross Validation of Two Partitioning-Based Sampling Approaches in Mesocosms Containing PCB Contaminated Field Sediment, Biota, and Activated Carbon Amendment

EPA Science Inventory

The Gold Standard for determining freely dissolved concentrations (Cfree) of hydrophobic organic compounds in sediment interstitial water would be in situ deployment combined with equilibrium sampling, which is generally difficult to achieve. In the present study, ex situ equilib...

Switchgrass and pecan biochar amendments to a sandy coastal soil

USDA-ARS?s Scientific Manuscript database

Sandy soils of the wet, warm SE Coastal Plain have poor physical characteristics and low carbon contents. To improve soil properties, we added switchgrass (Panicum virgatum) and non-activated pecan (Carya illinoinensis) biochar. Switchgrass was ground to a fine powder and added to soil at rates of 0...

Microbial community-level physiological profiling based on O2 consumption as an indicator of nitrogen status of agricultural soils

USDA-ARS?s Scientific Manuscript database

Nitrogen-limited soil microbial activity has important implications for soil carbon storage and nutrient availability, but previous methods for assessing resource limitation have been restricted, due to enrichment criteria (i.e., long incubation periods, high substrate amendments) and/or logistical ...

Linking organic carbon, water content and nitrous oxide emission in a reclaimed coal mine soil

USDA-ARS?s Scientific Manuscript database

Manure-based organic amendments can restore soil quality and allow for intensive sustained biomass production on degraded lands. However the large quantities of nitrogen and organic carbon added with such amendments could create soil conditions favorable for nitrous oxide production and emissions. T...

Field application of activated carbon amendment for in-situ stabilization of polychlorinated biphenyls in marine sediment.

PubMed

Cho, Yeo-Myoung; Ghosh, Upal; Kennedy, Alan J; Grossman, Adam; Ray, Gary; Tomaszewski, Jeanne E; Smithenry, Dennis W; Bridges, Todd S; Luthy, Richard G

2009-05-15

We report results on the first field-scale application of activated carbon (AC) amendment to contaminated sediment for in-situ stabilization of polychlorinated biphenyls (PCBs). The test was performed on a tidal mud flat at South Basin, adjacent to the former Hunters Point Naval Shipyard, San Francisco Bay, CA. The major goals of the field study were to (1) assess scale up of the AC mixing technology using two available, large-scale devices, (2) validate the effectiveness of the AC amendment at the field scale, and (3) identify possible adverse effects of the remediation technology. Also, the test allowed comparison among monitoring tools, evaluation of longer-term effectiveness of AC amendment, and identification of field-related factors that confound the performance of in-situ biological assessments. Following background pretreatment measurements, we successfully incorporated AC into sediment to a nominal 30 cm depth during a single mixing event, as confirmed by total organic carbon and black carbon contents in the designated test plots. The measured AC dose averaged 2.0-3.2 wt% and varied depending on sampling locations and mixing equipment. AC amendment did not impact sediment resuspension or PCB release into the water column over the treatment plots, nor adversely impactthe existing macro benthic community composition, richness, or diversity. The PCB bioaccumulation in marine clams was reduced when exposed to sediment treated with 2% AC in comparison to the control plot Field-deployed semi permeable membrane devices and polyethylene devices showed about 50% reduction in PCB uptake in AC-treated sediment and similar reduction in estimated pore-water PCB concentration. This reduction was evident even after 13-month post-treatment with then 7 months of continuous exposure, indicating AC treatment efficacy was retained for an extended period. Aqueous equilibrium PCB concentrations and PCB desorption showed an AC-dose response. Field-exposed AC after 18 months retained a strong stabilization capability to reduce aqueous equilibrium PCB concentrations by about 90%, which also supports the long-term effectiveness of AC in the field. Additional mixing during or after AC deployment, increasing AC dose, reducing AC-particle size, and sequential deployment of AC dose will likely improve AC-sediment contact and overall effectiveness. The reductions in PCB availability observed with slow mass transfer under field conditions calls for predictive models to assess the long-term trends in pore-water PCB concentrations and the benefits of alternative in-situ AC application and mixing strategies.

Biogenic coal-to-methane conversion efficiency decreases after repeated organic amendment

USGS Publications Warehouse

Davis, Katherine J.; Barnhart, Elliott P.; Fields, Matthew W.; Gerlach, Robin

2018-01-01

Addition of organic amendments to coal-containing systems can increase the rate and extent of biogenic methane production for 60–80 days before production slows or stops. Understanding the effect of repeated amendment additions on the rate and extent of enhanced coal-dependent methane production is important if biological coal-to-methane conversion is to be enhanced on a commercial scale. Microalgal biomass was added at a concentration of 0.1 g/L to microcosms with and without coal on days 0, 76, and 117. Rates of methane production were enhanced after the initial amendment but coal-containing treatments produced successively decreasing amounts of methane with each amendment. During the first amendment period, 113% of carbon added as amendment was recovered as methane, whereas in the second and third amendment periods, 39% and 32% of carbon added as amendment was recovered as methane, respectively. Additionally, algae-amended coal treatments produced ∼38% more methane than unamended coal treatments and ∼180% more methane than amended coal-free treatments after one amendment. However, a second amendment addition resulted in only an ∼25% increase in methane production for coal versus noncoal treatments and a third amendment addition resulted in similar methane production in both coal and noncoal treatments. Successive amendment additions appeared to result in a shift from coal-to-methane conversion to amendment-to-methane conversion. The reported results indicate that a better understanding is needed of the potential impacts and efficiencies of repeated stimulation for enhanced coal-to-methane conversion.

Use of commercial soil amendments in initial soils (II) - Impact on soil respiratory and carbon isotopic characteristics

NASA Astrophysics Data System (ADS)

Nii-Annang, S.; Rodionov, A.; Dilly, O.; Bens, O.; Raab, T.; Hüttl, R. F.

2009-04-01

The search for viable re-cultivation techniques for the reclamation of large scale soil disturbances induced by mining of mineral resources has increasingly received attention in recent times. These techniques should favour plant growth under dry conditions and under nutrient-poor substrates; a problem in the lignite mining district in Lusatia, Germany. Substrates with basal respiration around 0.04 µg CO2 g-1 h-1, which is relatively low compared to mature soils, were amended with two nutrient rich commercial soil additives (CSA 1 and CSA 2). The CSA 1 is a synthetic-mineral mixture and CSA 2 an organo-mineral mixture. The amendment stimulated basal respiration based on both carbon dioxide evolution and oxygen uptake by 150 and 125 % for SCA 1 and CSA 2, respectively when 1 % of each additive was thoroughly mixed with substrate in a laboratory study. The stimulating effect was evident after glucose addition to CSA 2. The CSA 1 application in the field at lower rates still showed apparent stimulation of soil respiratory activities after one year. Similarly, the organo-mineral-mixture has prominent effects on basal respiration and substrate-induced respiration when glucose was added. We concluded that the commercial additives used as long-term amelioration techniques increased both nutrient preservation and, to some extent, soil microbial activity.

Microbial activities in hydrocarbon-laden wastewaters: Impact on diesel fuel stability and the biocorrosion of carbon steel.

PubMed

Liang, Renxing; Duncan, Kathleen E; Le Borgne, Sylvie; Davidova, Irene; Yakimov, Michail M; Suflita, Joseph M

2017-08-20

Anaerobic hydrocarbon biodegradation not only diminishes fuel quality, but also exacerbates the biocorrosion of the metallic infrastructure. While successional events in marine microbial ecosystems impacted by petroleum are well documented, far less is known about the response of communities chronically exposed to hydrocarbons. Shipboard oily wastewater was used to assess the biotransformation of different diesel fuels and their propensity to impact carbon steel corrosion. When amended with sulfate and an F76 military diesel fuel, the sulfate removal rate in the assay mixtures was elevated (26.8μM/d) relative to incubations receiving a hydroprocessed biofuel (16.1μM/d) or a fuel-unamended control (17.8μM/d). Microbial community analysis revealed the predominance of Anaerolineae and Deltaproteobacteria in F76-amended incubations, in contrast to the Beta- and Gammaproteobacteria in the original wastewater. The dominant Smithella-like sequences suggested the potential for syntrophic hydrocarbon metabolism. The general corrosion rate was relatively low (0.83 - 1.29±0.12mpy) and independent of the particular fuel, but pitting corrosion was more pronounced in F76-amended incubations. Desulfovibrionaceae constituted 50-77% of the sessile organisms on carbon steel coupons. Thus, chronically exposed microflora in oily wastewater were differentially acclimated to the syntrophic metabolism of traditional hydrocarbons but tended to resist isoalkane-laden biofuels. Copyright © 2017 Elsevier B.V. All rights reserved.

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.

A large column analog experiment of stable isotope variations during reactive transport: II. Carbon mass balance, microbial community structure and predation

NASA Astrophysics Data System (ADS)

Druhan, Jennifer L.; Bill, Markus; Lim, HsiaoChien; Wu, Cindy; Conrad, Mark E.; Williams, Kenneth H.; DePaolo, Donald J.; Brodie, Eoin L.

2014-01-01

Here we report a combined analysis of carbon mass balance based on isotopic labeling and microbiological characterization during organic carbon stimulated bioreduction of a subsurface sediment in a large laboratory column experimental system. This combination of approaches allows quantification of both the cycling of carbon through multiple redox pathways and the associated spatial and temporal evolution of bacterial communities in response to this nutrient source. Carbon isotope mass balance facilitated by the use of 13C-labeled acetate as the electron donor showed evidence for a net loss of sediment organic carbon over the course of the amendment experiment. Furthermore, these data clearly demonstrated a source of isotopically labeled inorganic carbon that was not attributable to primary metabolism by acetate-oxidizing microorganisms. Fluid samples collected weekly over the duration of the 43-day amendment at <20 cm intervals along the flow path were analyzed for microbial composition by pyrosequencing of ribosomal RNA genes. The microbial community composition was transient, with distinct occurrences of Azoarcus, Geobacter and multiple sulfate reducing species over the course of the experiment. In combination with DNA sequencing data, the anomalous carbon cycling process is shown to occur exclusively during the period of predominant Geobacter species growth. Pyrosequencing indicated, and targeted cloning and sequencing confirmed the presence of several bacteriovorous protozoa, including species of the Breviata, Planococcus and Euplotes genera. Cloning and qPCR analysis demonstrated that Euplotes species were most abundant and displayed a growth trajectory that closely followed that of the Geobacter population. These results suggest a previously undocumented secondary turnover of biomass carbon related to protozoan grazing that was not sufficiently prevalent to be observed in bulk concentrations of carbon species in the system, but was clearly identified in the partitioning of carbon isotopes. This study demonstrates evidence for predator-prey relationships that impact subsurface microbial community dynamics and provides a novel indication of the impact of this relationship on the flux of carbon through a system via the microbial biomass pool. Overall, our approach provides high temporal and spatial sampling resolution at field relevant flow rates, while minimizing effects of mixing and transverse dispersion. The result is a quantitative carbon budget accounting for a diversity of processes that should be considered for inclusion in reactive transport models that aim to predict carbon turnover, nutrient flux, and redox reactions in natural and stimulated subsurface systems. the mobilization of previously stabilized, sediment-bound carbon; a carbon mass balance for a through-flowing sediment column over the course of a 43-day amendment using 13C-labeled acetate; a phylogenetic microbial community structure at <20 cm sampling resolution with distance away from the organic carbon source weekly over the 43-day amendment; protozoan grazing on the active Geobacteraceae population and the rapid turnover of microbial biomass carbon as a secondary cycling pathway. Such a high resolution, combined analysis of microbial populations and the associated carbon mass balance in a through-flowing system at field relevant flow rates provides novel, quantitative insights into the interface between biogeochemical cycling and bulk carbon fluxes in the near-surface environment.

75 FR 73033 - Circular Welded Carbon Steel Pipes and Tubes from Thailand: Amended Final Results of Antidumping...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-29

... Pipes and Tubes from Thailand: Amended Final Results of Antidumping Duty Administrative Review AGENCY... Thailand, covering the period March 1, 2008 through February 28, 2009. The final results were subsequently... Circular Welded Carbon Steel Pipes and Tubes From Thailand: Final Results of Antidumping Duty...

Microbial Community Response to Carbon Substrate Amendment in Mercury Impacted Sediments: Implications on Microbial Methylation of Mercury.

NASA Astrophysics Data System (ADS)

Elias, D. A.; Somenahally, A. C.; Moberly, J. G.; Hurt, R. A., Jr.; Brown, S. D.; Podar, M.; Palumbo, A. V.; Gilmour, C. C.

2015-12-01

Methylmercury (MeHg) is a neurotoxic and bio-accumulative product of the microbial methylation of inorganic mercury (Hg(II)). Methylating organisms are now known to exist in almost all anaerobic niches including fermentation, Fe(III)- and sulfate- reduction as well as methanogenesis. The study objective was to determine the effect of different carbon sources on the microbial community and methylating populations in particular along a Hg contaminated creek. Sediment cores from upstream and downstream at the Hg contaminated East Fork Poplar Creek (EFPC), Oak Ridge TN, and a background site were sectioned by depth, and Hg-methylation potential (HgMP) assays were performed using stable isotope spikes. Sediments from the lowest depth possessed the highest in-situ activity. Replicate samples were amended with different carbon substrates (cellulose, acetate, propionate, lactate, ethanol and methanol), spiked with stable isotopes for HgMP assays and incubated for 24hrs. Sequencing of the 16S rRNA gene was performed to determine alterations in Bacterial and Archaeal population dynamics. Additionally, bioinformatics and our new qualitative and quantitative hgcAB primers were utilized to determine microbial community structure alterations and correlate organism and gene abundance with altered MeHg generation. HgMP was significantly reduced in cellulose amended sediments while acetate and propionate slightly decreased HgMP in both sites. Methanol, ethanol and lactate increased the HgMP in EFPC downstream while cellulose amendment significantly decreased the Proteobacteria, and the Firmicutes increased but none are currently known to produce MeHg. Geobacter bemidjiensis in particular significantly decreased in cellulose amended sediments in all three sites from being predominant in-situ. This suggests that in EFPC downstream and background sites, the prevalent Hg-methyaltors might be Deltaprotebacteria, since upstream, cellulose amendment did not reduce HgMP even though relative composition of Deltaproteobacteria decreased significantly. Hence the phylogenetic distribution of Hg-methylating bacteria upstream may be much broader. Most Archaea belonged to either Euryarchaeota or Crenarchaeota, but there were no consistent trends with specific groups among the treatments.

Effect of fire residues (ash and char) on microbial activity, respiration and methanogenesis in three subtropical wetland soils

NASA Astrophysics Data System (ADS)

Medvedeff, C.; Hogue, B.; Inglett, P.

2011-12-01

Prescribed fire is a common restoration and maintenance technique in the southern United States. Prescribed burns coupled with frequent natural fires in South Florida can have devastating effects on ecosystem function. To determine the effect fire residues have on carbon biogeochemical cycling litter material was obtained from two restored and one native marl wetland in Everglades National Park and manipulated in a laboratory setting to produce ash and vegetation derived char. Based on vegetation biomass removal pre and post fire (insitu) appropriate aliquots of each fire residue was added to experimental microcosms as a soil amendment. Soil enzymes (β-glucosidase, cellobiohydrolase, phosphatase, bis-phosphate and leucine amino peptidase), aerobic and anaerobic respiration (CO2) potentials, extractable C and methanogenesis were measured over a 25 day period. Regardless of site C enzymes responded to both amendments within 5 days of addition. Similarly amended soil contained more extractable carbon in the reference and one of the restored sites. In the restored sites ash and char inhibited methanogenesis, had no effect on anaerobic CO2 potentials, but stimulated aerobic respiration after ten days. In contrast, within the first ten days phosphatase enzyme activity was lower in the ash treatment when compared to the control treatment and stimulation of aerobic respiration was observed in both treatment soils. After ten days ash stimulated methanogenic processing while suppressing anaerobic CO2 production suggesting methanogens in this ecosystem may be dependant on usable carbon substrates derived from aerobic microbial processing. This study illustrates the variable response of C parameters to complete and incomplete combusted materials produced from both prescribed and natural fires with particular importance to fire adapted ecosystems.

REMOVAL OF ORGANIC CCL CONTAMINANTS FROM DRINKING WATERS BY ENHANCED COAGULATION, POWDERED ACTIVATED CARBON, CHEMICAL SOFTENING, AND OXIDATION

EPA Science Inventory

The 1996 amendments to the Safe Drinking Water Act (SWDA) require the US Environmental Protection Agency (USEPA) to establish a list of unregulated microbiological and chemical contaminants to aid in priority-setting for the Agency's drinking water program. This list, known as t...

Impact of organic carbon and nutrients mobilized during chemical oxidation on subsequent bioremediation of a diesel-contaminated soil.

PubMed

Sutton, Nora B; Grotenhuis, Tim; Rijnaarts, Huub H M

2014-02-01

Remediation with in situ chemical oxidation (ISCO) impacts soil organic matter (SOM) and the microbial community, with deleterious effects on the latter being a major hurdle to coupling ISCO with in situ bioremediation (ISB). We investigate treatment of a diesel-contaminated soil with Fenton's reagent and modified Fenton's reagent coupled with a subsequent bioremediation phase of 187d, both with and without nutrient amendment. Chemical oxidation mobilized SOM into the liquid phase, producing dissolved organic carbon (DOC) concentrations 8-16 times higher than the untreated field sample. Higher aqueous concentrations of nitrogen and phosphorous species were also observed following oxidation; NH4(+) increased 14-172 times. During the bioremediation phase, dissolved carbon and nutrient species were utilized for microbial growth-yielding DOC concentrations similar to field sample levels within 56d of incubation. In the absence of nutrient amendment, the highest microbial respiration rates were correlated with higher availability of nitrogen and phosphorus species mobilized by oxidation. Significant diesel degradation was only observed following nutrient amendment, implying that nutrients mobilized by chemical oxidation can increase microbial activity but are insufficient for bioremediation. While all bioremediation occurred in the first 28d of incubation in the biotic control microcosm with nutrient amendment, biodegradation continued throughout 187d of incubation following chemical oxidation, suggesting that chemical treatment also affects the desorption of organic contaminants from SOM. Overall, results indicate that biodegradation of DOC, as an alternative substrate to diesel, and biological utilization of mobilized nutrients have implications for the success of coupled ISCO and ISB treatments. Copyright © 2013 Elsevier Ltd. All rights reserved.

Impact of non-ionic surfactant on the long-term development of lab-scale-activated sludge bacterial communities.

PubMed

Lozada, Mariana; Basile, Laura; Erijman, Leonardo

2007-01-01

The development of bacterial communities in replicate lab-scale-activated sludge reactors degrading a non-ionic surfactant was evaluated by statistical analysis of denaturing gradient gel electrophoresis (DGGE) fingerprints. Four sequential batch reactors were fed with synthetic sewage, two of which received, in addition, 0.01% of nonylphenol ethoxylates (NPE). The dynamic character of bacterial community structure was confirmed by the differences in species composition among replicate reactors. Measurement of similarities between reactors was obtained by pairwise similarity analysis using the Bray Curtis coefficient. The group of NPE-amended reactors exhibited the highest similarity values (Sjk=0.53+/-0.03), indicating that the bacterial community structure of NPE-amended reactors was better replicated than control reactors (Sjk=0.36+/-0.04). Replicate NPE-amended reactors taken at different times of operation clustered together, whereas analogous relations within the control reactor cluster were not observed. The DGGE pattern of isolates grown in conditioned media prepared with media taken at the end of the aeration cycle grouped separately from other conditioned and synthetic media regardless of the carbon source amendment, suggesting that NPE degradation residuals could have a role in the shaping of the community structure.

Effect of dairy manure rate and the stabilization time of amended soils on atrazine degradation.

PubMed

Aguilera, Paula; Briceño, Gabriela; Candia, Maribel; Mora, Maria de la Luz; Demanet, Rolando; Palma, Graciela

2009-10-01

The application rate of liquid cow manure (LCM) in the field and the stabilization time of amended soils before application of pre-plant herbicides are factors that determine their efficiency. This study includes evaluation of residual atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine) in soil and amended soils with equivalent rate of 100,000; 200,000; and 300,000 L ha(-1) of LCM and the effect of pre-incubation time of amended soils on atrazine degradation. The study was carried out under controlled conditions using an Andisol with previous historical application of atrazine. The respiratory activity and fluorescein diacetate (FDA) studies indicated that the time necessary for stabilization of amended soils is over 20-30 d. During the measurement of respiratory and FDA activity, no significant differences were observed when atrazine was applied. The half-life of atrazine ranged from 5 to 8d and the relative distribution of degradation products seem to be affected by the application of LCM. The pre-incubation time of amended soil and LCM dose would not affect atrazine degradation rate, when the soil has a history of herbicide application. However, repeated applications of LCM in a long period of time could change the soil pH and increase the content of dissolved organic carbon (DOC) which could further contribute to a faster degradation of atrazine. Both effects would reduce the effectiveness of atrazine in weed control.

Zinc oxide nanoparticles affect carbon and nitrogen mineralization of Phoenix dactylifera leaf litter in a sandy soil.

PubMed

Rashid, Muhammad Imtiaz; Shahzad, Tanvir; Shahid, Muhammad; Ismail, Iqbal M I; Shah, Ghulam Mustafa; Almeelbi, Talal

2017-02-15

We investigated the impact of zinc oxide nanoparticles (ZnO NPs; 1000mgkg -1 soil) on soil microbes and their associated soil functions such as date palm (Phoenix dactylifera) leaf litter (5gkg -1 soil) carbon and nitrogen mineralization in mesocosms containing sandy soil. Nanoparticles application in litter-amended soil significantly decreased the cultivable heterotrophic bacterial and fungal colony forming units (cfu) compared to only litter-amended soil. The decrease in cfu could be related to lower microbial biomass carbon in nanoparticles-litter amended soil. Likewise, ZnO NPs also reduced CO 2 emission by 10% in aforementioned treatment but this was higher than control (soil only). Labile Zn was only detected in the microbial biomass of nanoparticles-litter applied soil indicating that microorganisms consumed this element from freely available nutrients in the soil. In this treatment, dissolved organic carbon and mineral nitrogen were 25 and 34% lower respectively compared to litter-amended soil. Such toxic effects of nanoparticles on litter decomposition resulted in 130 and 122% lower carbon and nitrogen mineralization efficiency respectively. Hence, our results entail that ZnO NPs are toxic to soil microbes and affect their function i.e., carbon and nitrogen mineralization of applied litter thus confirming their toxicity to microbial associated soil functions. Copyright © 2016 Elsevier B.V. All rights reserved.

76 FR 27987 - Circular Welded Carbon Steel Pipes and Tubes From Thailand: Amended Final Results of Antidumping...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-13

... Pipes and Tubes From Thailand: Amended Final Results of Antidumping Duty Administrative Review Pursuant... tubes from Thailand, which covered Saha Thai Steel Pipe (Public) Co., Ltd. (Saha Thai) and the period March 1, 2006, through February 28, 2007. See Circular Welded Carbon Steel Pipes and Tubes from Thailand...

Reactive amendment saltstone (RAS). A novel approach for improved sorption/retention of radionuclides such as technetium and iodine

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

Dixon, K. L.; Knox, A. S.; Cozzi, A. D.

This study examined the use of reactive amendments (hydroxyapatite, activated carbon, and two types of organoclays) that prior research suggests may improve retention of 99Tc and 129I. Tests were conducted using surrogates for 99Tc (NaReO 4) and 129I (NaI). Results showed that adding up to 10% of organoclay improved the retention of Re without adversely impacting hydraulic properties. To a lesser extent, iodine retention was also improved by adding up to 10% organoclay. Numerical modeling showed that using organoclay as a reactive barrier may significantly retard 99Tc release from saltstone disposal units.

Effects of Trophic Modes, Carbon Sources, and Salinity on the Cell Growth and Lipid Accumulation of Tropic Ocean Oilgae Strain Desmodesmus sp. WC08.

PubMed

Zhao, Zhenyu; Ma, Shasha; Li, Ang; Liu, Pinghuai; Wang, Meng

2016-10-01

The effects of trophic modes, carbon sources, and salinity on the growth and lipid accumulation of a marine oilgae Desmodesmus sp. WC08 in different trophic cultures were assayed by single factor experiment based on the blue-green algae medium (BG-11). The results implied that biomass and lipid accumulation culture process were optimized depending on the tophic modes, sorts, and concentration of carbon sources and salinity in the cultivation. There was no significant difference in growth or lipid accumulation with Na 2 CO 3 amendment or NaHCO 3 amendment. However, Na 2 CO 3 amendment did enhance the biomass and lipid accumulation to some extent. The highest Desmodesmus sp. WC08 biomass and lipid accumulation was achieved in the growth medium with photoautotrophic cultivation, 0.08 g L -1 Na 2 CO 3 amendment and 15 g L -1 sea salt, respectively.

Understanding sucrose metabolism and growth in a developing sweetgum plantation.

Treesearch

Shi-Jean S. Sung; Paul P. Kormanik; C.C. Black

1994-01-01

Stem diameter growth of 9-year-old sweetgum (Liquidambar styraciflua) trees was measured and related with the activity of sucrose synthase (SS), an enzyme that has been associated with carbon sink strength in agriculture crops and tree seedlings. In 1984, 10 sweetgum seedlings were transplanted to control plots and plots amended with sewage sludge or nitorgen and...

Transport and attenuation of metal(loid)s in mine tailings amended with organic carbon: Column experiments

NASA Astrophysics Data System (ADS)

Lindsay, Matthew B. J.; Blowes, David W.; Ptacek, Carol J.; Condon, Peter D.

2011-07-01

A laboratory-scale column experiment was conducted to evaluate the effect of organic carbon amendments on the mobility of As, Cu, Fe, Mn, Mo, Ni, Pb, Sb, Tl and Zn in mine tailings. Three columns were packed with sulfide- and carbonate-rich tailings, which were amended with a 1:1 (vol.) mixture of peat and spent brewing grain at proportions of 0, 2 and 5 vol. %. A simulated input solution characterized by circumneutral pH and elevated concentrations of SO 4 and S 2O 3 was passed through the columns for 540 days. The input solution contained low concentrations of metal(loid)s during the initial 300 days and elevated concentrations thereafter. Decreases in mass transport of S 2O 3 were observed in all columns; with increased attenuation observed at 5 vol. % organic carbon content. Removal of Mn, Ni, Cu, Sb and Mo was observed in all columns during the initial 300 days. However, during this time, mobilization of Fe, As, Zn and Pb was observed, with the greatest increases in concentration observed at the higher organic carbon content. During the final 240 days, S 2O 3 removal was enhanced in columns containing organic carbon, and Fe, Mn, Ni, Tl, As and Sb removal also was observed. This study demonstrates the influence of organic carbon amendments on metal(loid) mobility in mine tailings. Decreases in mass discharge of metal(loid)s may be achieved using this technique; however, site-specific geochemical conditions must be considered before field-scale implementation.

77 FR 10423 - Approval and Promulgation of Air Quality Implementation Plans; West Virginia; Amendments to West...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-22

... Promulgation of Air Quality Implementation Plans; West Virginia; Amendments to West Virginia's Ambient Air... ambient air quality standards (45CSR8- Ambient Air Quality Standards). These amendments incorporate by reference the National Ambient Air Quality Standards (NAAQS) for sulfur dioxide, particulate matter, carbon...

The influence of redox chemistry and pH on chemically active forms of arsenic in sewage sludge-amended soil

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

Carbonell-Barrachina, A.; Jugsujinda, A.; DeLaune, R.D.

1999-07-01

Chemical fractionation procedures were used to quantify the effect of the sediment redox and pH conditions on the adsorption and solubility of arsenic (As) in municipal sewage sludge and sewage sludge-amended soil. Sludge and sludge-amended soil were incubated in microcosms in which Eh-pH conditions were controlled. Samples were sequentially extracted to determine As in various chemical forms (water soluble, exchangeable, bound to carbonates, bound to iron (Fe) and manganese (Mn) oxides, bound to insoluble organics and sulfides) and the chemically inactive fraction (mineral residues). In both sewage sludge and sludge-amended soil, As chemistry was governed by large molecular humic mattermore » and sulfides and Fe and Mn-oxides. Solubility of As remained low and constant under both aerobic and anaerobic conditions in sludge-amended soil. After dissolution of Fe and Mn-oxides, As{sup 5+} was released into sludge solution, reduced to As{sup 3+} and likely precipitated as sulfide. Therefore, an organic amendment rich in sulfur compounds, such as sewage sludge, would drastically reduce the potential risks derived from As pollution under highly anoxic conditions by precipitation of this toxic metalloid as insoluble and immobile sulfides.« less

Secondary environmental impacts of remedial alternatives for sediment contaminated with hydrophobic organic contaminants.

PubMed

Choi, Yongju; Thompson, Jay M; Lin, Diana; Cho, Yeo-Myoung; Ismail, Niveen S; Hsieh, Ching-Hong; Luthy, Richard G

2016-03-05

This study evaluates secondary environmental impacts of various remedial alternatives for sediment contaminated with hydrophobic organic contaminants using life cycle assessment (LCA). Three alternatives including two conventional methods, dredge-and-fill and capping, and an innovative sediment treatment technique, in-situ activated carbon (AC) amendment, are compared for secondary environmental impacts by a case study for a site at Hunters Point Shipyard, San Francisco, CA. The LCA results show that capping generates substantially smaller impacts than dredge-and-fill and in-situ amendment using coal-based virgin AC. The secondary impacts from in-situ AC amendment can be reduced effectively by using recycled or wood-based virgin AC as production of these materials causes much smaller impacts than coal-based virgin AC. The secondary environmental impacts are highly sensitive to the dredged amount and the distance to a disposal site for dredging, the capping thickness and the distance to the cap materials for capping, and the AC dose for in-situ AC amendment. Based on the analysis, this study identifies strategies to minimize secondary impacts caused by different remediation activities: optimize the dredged amount, the capping thickness, or the AC dose by extensive site assessments, obtain source materials from local sites, and use recycled or bio-based AC. Copyright © 2015 Elsevier B.V. All rights reserved.

Initiation of soil formation in weathered sulfidic Cu-Pb-Zn tailings under subtropical and semi-arid climatic conditions.

PubMed

You, Fang; Dalal, Ram; Huang, Longbin

2018-08-01

Field evidence has been scarce about soil (or technosol) formation and direct phytostabilization of base metal mine tailings under field conditions. The present study evaluated key attributes of soil formation in weathered and neutral Cu-Pb-Zn tailings subject to organic amendment (WC: woodchips) and colonization of pioneer native plant species (mixed native woody and grass plant species) in a 2.5-year field trial under subtropical and semi-arid climatic conditions. Key soil indicators of engineered soil formation process were characterized, including organic carbon fractions, aggregation, microbial community and key enzymatic activities. The majority (64-87%) of the OC was stabilized in microaggregate or organo-mineral complexes in the amended tailings. The levels of OC and water soluble OC were elevated by 2-3 folds across the treatments, with the highest level in the treatment of WC and plant colonization (WC+P). Specifically, the WC+P treatment increased the proportion of water stable macroaggregates. Plants further contributed to the N rich organic matter in the tailings, favouring organo-mineral interactions and organic stabilization. Besides, the plants played a major role in boosting microbial biomass and activities in the treated tailings. WC and plants enhanced the contents of organic carbon (OC) associated with aggregates (e.g., physically protected OC), formation of water-stable aggregates (e.g., micro and macroaggregates), chemical buffering capacity (e.g., cation exchange capacity). Microbial community and enzymatic activities were also stimulated in the amended tailings. The present results showed that the formation of functional technosol was initiated in the eco-engineered and weathered Cu-Pb-Zn tailings under field conditions for direct phytostabilization. Copyright © 2018 Elsevier Ltd. All rights reserved.

Bioavailability assessments following biochar and activated carbon amendment in DDT-contaminated soil.

PubMed

Denyes, Mackenzie J; Rutter, Allison; Zeeb, Barbara A

2016-02-01

The effects of 2.8% w/w granulated activated carbon (GAC) and two types of biochar (Burt's and BlueLeaf) on DDT bioavailability in soil (39 μg/g) were investigated using invertebrates (Eisenia fetida), plants (Cucurbita pepo spp. pepo) and a polyoxymethylene (POM) passive sampler method. Biochar significantly reduced DDT accumulation in E. fetida (49%) and showed no detrimental effects to invertebrate health. In contrast, addition of GAC caused significant toxic effects (invertebrate avoidance and decreased weight) and did not significantly reduce the accumulation of DDT into invertebrate tissue. None of the carbon amendments reduced plant uptake of DDT. Bioaccumulation of 4,4'DDT and 4,4'-DDE in plants (C. pepo spp. pepo) and invertebrates (E. fetida) was assessed using bioaccumulation factors (BAFs) and compared to predicted bioavailability using the freely-dissolved porewater obtained from a polyoxymethylene (POM) equilibrium biomimetic method. The bioavailable fraction predicted by the POM samplers correlated well with measured invertebrate uptake (<50% variability), but was different from plant root uptake by 134%. A literature review of C. pepo BAFs across DDT soil contamination levels and the inclusion of field data from a 2.5 μg/g DDT-contaminated site found that these plants exhibit a concentration threshold effect at [DDT](soil) > 10 μg/g. The results of these studies illustrate the importance of including plants in bioavailability studies as the use of carbon materials for in situ contaminant sorption moves from predominantly sediment to soil remediation technologies. Copyright © 2015 Elsevier Ltd. All rights reserved.

Laboratory evaluation of surface amendments for controlling greenhouse gas emissions from beef cattle feedlots.

USDA-ARS?s Scientific Manuscript database

Pen surface amendments for mitigating emissions of greenhouse gases (GHGs), such as nitrous oxide (N2O), methane (CH4), and carbon dioxide (CO2), from beef cattle feedlots, were evaluated under controlled laboratory conditions. Amendments were organic residues (i.e., sorghum straw, prairie grass, wo...

Zeolite Combined with Alum and Polyaluminum Chloride Mixed with Agricultural Slurries Reduces Carbon Losses in Runoff from Grassed Soil Boxes.

PubMed

Murnane, J G; Brennan, R B; Fenton, O; Healy, M G

2016-11-01

Carbon (C) losses from agricultural soils to surface waters can migrate through water treatment plants and result in the formation of disinfection by-products, which are potentially harmful to human health. This study aimed to quantify total organic carbon (TOC) and total inorganic C losses in runoff after application of dairy slurry, pig slurry, or milk house wash water (MWW) to land and to mitigate these losses through coamendment of the slurries with zeolite (2.36-3.35 mm clinoptilolite) and liquid polyaluminum chloride (PAC) (10% AlO) for dairy and pig slurries or liquid aluminum sulfate (alum) (8% AlO) for MWW. Four treatments under repeated 30-min simulated rainfall events (9.6 mm h) were examined in a laboratory study using grassed soil runoff boxes (0.225 m wide, 1 m long; 10% slope): control soil, unamended slurries, PAC-amended dairy and pig slurries (13.3 and 11.7 kg t, respectively), alum-amended MWW (3.2 kg t), combined zeolite and PAC-amended dairy (160 and 13.3 kg t zeolite and PAC, respectively) and pig slurries (158 and 11.7 kg t zeolite and PAC, respectively), and combined zeolite and alum-amended MWW (72 and 3.2 kg t zeolite and alum, respectively). The unamended and amended slurries were applied at net rates of 31, 34, and 50 t ha for pig and dairy slurries and MWW, respectively. Significant reductions of TOC in runoff compared with unamended slurries were measured for PAC-amended dairy and pig slurries (52 and 56%, respectively) but not for alum-amended MWW. Dual zeolite and alum-amended MWW significantly reduced TOC in runoff compared with alum amendment only. We conclude that use of PAC-amended dairy and pig slurries and dual zeolite and alum-amended MWW, although effective, may not be economically viable to reduce TOC losses from organic slurries given the relatively low amounts of TOC measured in runoff from unamended slurries compared with the amounts applied. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Application of ultrafiltration and stable isotopic amendments to field studies of mercury partitioning to filterable carbon in lake water and overland runoff.

PubMed

Babiarz, Christopher L; Hurley, James P; Krabbenhoft, David P; Gilmour, Cynthia; Branfireun, Brian A

2003-03-20

Results from pilot studies on colloidal phase transport of newly deposited mercury in lake water and overland runoff demonstrate that the combination of ultrafiltration, and stable isotope amendment techniques is a viable tool for the study of mercury partitioning to filterable carbon. Ultrafiltration mass balance calculations were generally excellent, averaging 97.3, 96.1 and 99.8% for dissolved organic carbon (DOC), total mercury (Hg(T)), and methylmercury (MeHg), respectively. Sub nanogram per liter quantities of isotope were measurable, and the observed phase distribution from replicate ultrafiltration separations on lake water agreed within 20%. We believe the data presented here are the first published colloidal phase mercury data on lake water and overland runoff from uncontaminated sites. Initial results from pilot-scale lake amendment experiments indicate that the choice of matrix used to dissolve the isotope did not affect the initial phase distribution of the added mercury in the lake. In addition there was anecdotal evidence that native MeHg was either recently produced in the system, or at a minimum, that this 'old' MeHg partitions to the same subset of DOC that binds the amended mercury. Initial results from pilot-scale overland runoff experiments indicate that less than 20% of newly deposited mercury was transported in the filterable fraction (<0.7 microm). There is some indication of colloidal phase enrichment of mercury in runoff compared to the phase distribution of organic carbon, but the mechanism of this enrichment is unclear. The phase distribution of newly deposited mercury can differ from that of organic carbon and native mercury, suggesting that the quality of the carbon (available ligands), not the quantity of carbon, regulates partitioning. Further characterization of DOC is needed to clarify the underlying mechanisms.

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.

Protistan Predation Affects Trichloroethene Biodegradation in a Bedrock Aquifer▿

PubMed Central

Cunningham, Joseph J.; Kinner, Nancy E.; Lewis, Maureen

2009-01-01

Despite extensive research on the bottom-up force of resource availability (e.g., electron donors and acceptors), slow biodegradation rates and stalling at cis-dichloroethene (cDCE) and vinyl chloride continue to be observed in aquifers contaminated with trichloroethene (TCE). The objective of this research was to gauge the impact of the top-down force of protistan predation on TCE biodegradation in laboratory microcosms. When indigenous bacteria from an electron donor-limited TCE-contaminated bedrock aquifer were present, the indigenous protists inhibited reductive dechlorination altogether. The presence of protists during organic carbon-amended conditions caused the bacteria to elongate (length:width, ≥10:1), but reductive dechlorination was still inhibited. When a commercially available dechlorinating bacterial culture and an organic carbon amendment were added in he presence of protists, the elongated bacteria predominated and reductive dechlorination stalled at cDCE. When protists were removed under organic carbon-amended conditions, reductive dechlorination stalled at cDCE, whereas in the presence organic carbon and bacterial amendments, the total chlorinated ethene concentration decreased, indicating TCE was converted to ethene and/or CO2. The data suggested that indigenous protists grazed dechlorinators to extremely low levels, inhibiting dechlorination altogether. Hence, in situ bioremediation/bioaugmentation may not be successful in mineralizing TCE unless the top-down force of protistan predation is inhibited. PMID:19820148

Evaluation of the effectiveness of sepiolite, bentonite, and phosphate amendments on the stabilization remediation of cadmium-contaminated soils.

PubMed

Sun, Yuebing; Sun, Guohong; Xu, Yingming; Liu, Weitao; Liang, Xuefeng; Wang, Lin

2016-01-15

A pot trial was conducted to assess the effectiveness of sepiolite, bentonite, and phosphate on the immobilization remediation of cadmium (Cd)-contaminated soils using a set of variables, namely, physiological traits, sequential extraction procedure, plant growth and Cd concentration, and soil enzymatic activities and microbial population. Results showed that superoxide dismutase and peroxidase activities in the leaves of Oryza sativa L. and catalase activities in soils were stimulated after applying the amendments. However, soluble protein contents in leaves and urease and invertase activities in soils were reduced from 7.1% to 31.7%, 1.0%-23.3%, and 21.1%-62.5%, respectively, compared with the control. Results of the sequence extraction procedures revealed that the exchangeable fraction of Cd in soils was mostly converted into carbonated-associated forms. The water soluble plus exchangeable fraction (SE) of Cd in soil decreased when treated with single and compound materials of sepiolite, bentonite and phosphate, which resulted in 13.2%-69.2% reduction compared with that of CK (control test). The amendments led to decreased Cd concentrations in roots, stems, leaves, brown rice, and rice hull by 16.2%-54.5%, 16.6%-42.8%, 19.6%-59.6%, 5.0%-68.2%, and 6.2%-20.4%, respectively. Higher bacterial and actinomycete amount indicated that remediation measures improved soil environmental quality. Composite amendments could be more efficiently used for the stabilization remediation of Cd contaminated soils with low Cd uptake and translocation in the plants and available contents of Cd in soil. Copyright © 2015 Elsevier Ltd. All rights reserved.

Laboratory and pilot-scale bioremediation of pentaerythritol tetranitrate (PETN) contaminated soil.

PubMed

Zhuang, Li; Gui, Lai; Gillham, Robert W; Landis, Richard C

2014-01-15

PETN (pentaerythritol tetranitrate), a munitions constituent, is commonly encountered in munitions-contaminated soils, and pose a serious threat to aquatic organisms. This study investigated anaerobic remediation of PETN-contaminated soil at a site near Denver Colorado. Both granular iron and organic carbon amendments were used in both laboratory and pilot-scale tests. The laboratory results showed that, with various organic carbon amendments, PETN at initial concentrations of between 4500 and 5000mg/kg was effectively removed within 84 days. In the field trial, after a test period of 446 days, PETN mass removal of up to 53,071mg/kg of PETN (80%) was achieved with an organic carbon amendment (DARAMEND) of 4% by weight. In previous laboratory studies, granular iron has shown to be highly effective in degrading PETN. However, for both the laboratory and pilot-scale tests, granular iron was proven to be ineffective. This was a consequence of passivation of the iron surfaces caused by the very high concentrations of nitrate in the contaminated soil. This study indicated that low concentration of organic carbon was a key factor limiting bioremediation of PETN in the contaminated soil. Furthermore, the addition of organic carbon amendments such as the DARAMEND materials or brewers grain, proved to be highly effective in stimulating the biodegradation of PETN and could provide the basis for full-scale remediation of PETN-contaminated sites. Copyright © 2013 Elsevier B.V. All rights reserved.

In situ sediment treatment using activated carbon: a demonstrated sediment cleanup technology.

PubMed

Patmont, Clayton R; Ghosh, Upal; LaRosa, Paul; Menzie, Charles A; Luthy, Richard G; Greenberg, Marc S; Cornelissen, Gerard; Eek, Espen; Collins, John; Hull, John; Hjartland, Tore; Glaza, Edward; Bleiler, John; Quadrini, James

2015-04-01

This paper reviews general approaches for applying activated carbon (AC) amendments as an in situ sediment treatment remedy. In situ sediment treatment involves targeted placement of amendments using installation options that fall into two general approaches: 1) directly applying a thin layer of amendments (which potentially incorporates weighting or binding materials) to surface sediment, with or without initial mixing; and 2) incorporating amendments into a premixed, blended cover material of clean sand or sediment, which is also applied to the sediment surface. Over the past decade, pilot- or full-scale field sediment treatment projects using AC-globally recognized as one of the most effective sorbents for organic contaminants-were completed or were underway at more than 25 field sites in the United States, Norway, and the Netherlands. Collectively, these field projects (along with numerous laboratory experiments) have demonstrated the efficacy of AC for in situ treatment in a range of contaminated sediment conditions. Results from experimental studies and field applications indicate that in situ sequestration and immobilization treatment of hydrophobic organic compounds using either installation approach can reduce porewater concentrations and biouptake significantly, often becoming more effective over time due to progressive mass transfer. Certain conditions, such as use in unstable sediment environments, should be taken into account to maximize AC effectiveness over long time periods. In situ treatment is generally less disruptive and less expensive than traditional sediment cleanup technologies such as dredging or isolation capping. Proper site-specific balancing of the potential benefits, risks, ecological effects, and costs of in situ treatment technologies (in this case, AC) relative to other sediment cleanup technologies is important to successful full-scale field application. Extensive experimental studies and field trials have shown that when applied correctly, in situ treatment via contaminant sequestration and immobilization using a sorbent material such as AC has progressed from an innovative sediment remediation approach to a proven, reliable technology. © 2014 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of SETAC.

Carbon dynamics of contrasting agricultural practices

NASA Astrophysics Data System (ADS)

Ghee, Claire; Hallett, Paul; Neilson, Roy; Robinson, David; Paterson, Eric

2013-04-01

Application of organic amendments can improve soil quality and provide crop nutrients. To optimise these agricultural benefits from organic applications, the capacity of microbe-driven nutrient and carbon cycling must be understood and exploited. Consideration is therefore required of the complex interactions between the rhizosphere, microbial biomass and organic amendment. We hypothesise that the labile C present in root exudates of plants increases the mineralisation of organic matter in soil, constituting a mechanism to promote nutrient acquisition. This mechanism is known as the 'priming effect', but is poorly understood in the context of agricultural carbon and nutrient management. Field data from the Centre of Sustainable Cropping (CSC) research platform (Dundee, Scotland, UK) are utilised to build an understanding of soil C and N fluxes between contrasting agricultural practices. The field site uses a split-plot design to compare (i) compost amended soils with reduced tillage and chemical inputs and (ii) conventionally managed soils, reflective of current UK commercial arable practice. Significant differences (p= <0.001) were identified between compost amended and conventionally managed soils at field-scale with respect to soil microbial biomass (SMB), total organic carbon (TOC) and mineral nitrogen. Investigation into the priming effect within compost amended soils was subsequently undertaken under laboratory conditions. Stable isotope analysis and measurements of soil biotic parameters were used to quantify priming resulting from Spring Barley (Hordeum vulgare cv. Optic) cultivation for (i) unamended and (ii) municipal compost incorporated soils. Compost treatments comprised amendments of 25, 50 and 150 t/Ha and planted soils were compared with unplanted controls. Soil mesocosms were maintained under controlled environmental conditions within labelling chambers supplied continuously with 13C-depleted CO2. Throughout a 41-day incubation period, soil CO2 efflux and dissolved organic carbon (DOC) was collected for quantification and 13C analysis. Following the incubation period, soils and plant material were harvested for nitrogen, carbon and δ13C analyses. Isotopic analyses allowed partitioning of the contributions of plant- and soil-derived organic matter sources to SMB, DOC and soil respiration. The results demonstrate a strong influence of plant-microbe interactions in mediating the mobilisation and mineralisation of stabilised organic fractions in soil, constituting a significant feedback to crop productivity through increased nutrient cycling.

Evolution of soil properties and metals in acid and alkaline mine tailing ponds after amendments and microorganisms application

NASA Astrophysics Data System (ADS)

Acosta, Jose A.; Faz, Ángel; Zornoza, Raúl; Martínez-Martínez, Silvia; Bech, Jaume

2015-04-01

Intense mining activities in the past were carried out in Cartagena-La Unión mining district, SE Spain, and caused excessive accumulation of toxic metals in tailing ponds which poses a high environmental and ecological risk. One of the remediation options gaining considerable interest in recent years is the in situ immobilization of metals. A corresponding reduction in the plant-available metal fraction allows re-vegetation and ecosystem restoration of the heavily contaminated sites. In addition, the use of microorganisms to improve the soil condition is a new tool used to increase spontaneous plant colonization. The aim of this research was to assess the effect of amendments (pig manure, sewage sludge, and lime) and microorganisms on the evolution of soil properties and metals in acid and alkaline tailing ponds and to evaluate the content of metals in Zygophylum fabago one year after amendments application. The study was carried out in two mine ponds (acid and alkaline). Twenty seven square field plots, each one consisting of 4 m2, were located in each pond. Four different doses of microorganism (EM) (0 ml, 20 ml, 100 ml and 200 ml of microorganism solution in each plot) and one dose of pig manure (5 kg per plot), sewage sludge (4 kg per plot) and lime (22 kg per plot) were used. Organic amendment doses were calculated according to European nitrogen legislations, and lime dose was calculated according with the potential acid production through total sulphur oxidation. Three replicates of each treatment (organic amendment + lime + microorganism dose 0, 1, 2, or 3) and control soil (with no amendments) were carried out. Plots were left to the semi-arid climate conditions after the addition of amendments to simulate real potential applications of the results. Soil samples was collected every 4 month from each plot during one year, after this time Zygophylum fabago plants were sampled from each plots. Soil properties including: pH, salinity, total, inorganic and organic carbon, total nitrogen, total phosphorus, potassium, total, bioextractable and soluble metals (Pb, Cu, Zn, As and Cd), basal respiration and microbial biomass carbon; and metals (Pb, Cu, Zn, As and Cd) in roots and shoot from Zygophylum fabago were analyzed. The results showed that the lime increased the concentration of inorganic carbon in both ponds and, therefore, increases the pH until neutral/alkaline values, especially in the acid mine pond, reducing the risk of mobility of As, Pb and Zn to the trophic chain and the risk of leaching and runoff. The application of pig manure increased the salinity in the acid mine pond, as well as the content of OC, TN, K and P in both ponds; also it caused a higher concentration of bioavailable and soluble Cu in both ponds due to the high content of Cu in the manure; finally, an higher concentration of bioavailable and soluble As was observed in the alkaline mine pond due to the formation of organic-metal complexes. The application of sewage sludge increased the content of OC and K in both mine ponds; also it caused an increase in the concentration of bioavailable and water soluble As and a slight increase in the water soluble Cu in the alkaline mine pond likely because of the formation of organic-metal complexes. Both organic amendments increased the microbial biomass carbon (MBC), especially pig manure, indicating that this amendment brings more amount of microorganisms than sewage sludge. Similarly, the application of EM increases MBC, especially in doses 2 and 3, improving soil conditions which favour plant colonization. Furthermore, microbial activity is increased after amendments and EM applications, especially when pig manure was used; indicating that organic matter from pig manure is more easily degradable by microorganisms than organic matter from sewage sludge. Finally, the results indicated that the application of EM promotes the absorption and subsequent translocation to leaves of Cu and As, while prevents the absorption of Cd and Zn in Zygophylum fabago.

Sorbent amendment as a remediation strategy to reduce PFAS mobility and leaching in a contaminated sandy soil from a Norwegian firefighting training facility.

PubMed

Hale, Sarah E; Arp, Hans Peter H; Slinde, Gøril Aasen; Wade, Emma Jane; Bjørseth, Kamilla; Breedveld, Gijs D; Straith, Bengt Fredrik; Moe, Kamilla Grotthing; Jartun, Morten; Høisæter, Åse

2017-03-01

Aqueous film-forming foams (AFFF) containing poly- and perfluoroalkyl substances (PFAS) used for firefighting have led to the contamination of soil and water at training sites. The unique physicochemical properties of PFAS results in environmental persistency, threatening water quality and making remediation of such sites a necessity. This work investigated the role of sorbent amendment to PFAS contaminated soils in order to immobilise PFAS and reduce mobility and leaching to groundwater. Soil was sampled from a firefighting training facility at a Norwegian airport and total and leachable PFAS concentrations were quantified. Perfluorooctanesulfonic acid (PFOS) was the most dominant PFAS present in all soil samples (between 9 and 2600 μg/kg). Leaching was quantified using a one-step batch test with water (L/S 10). PFOS concentrations measured in leachate water ranged between 1.2 μg/L and 212 μg/L. Sorbent amendment (3%) was tested by adding activated carbon (AC), compost soil and montmorillonite to selected soils. The extent of immobilisation was quantified by measuring PFAS concentrations in leachate before and after amendment. Leaching was reduced between 94 and 99.9% for AC, between 29 and 34% for compost soil and between 28 and 40% for the montmorillonite amended samples. Sorbent + soil/water partitioning coefficients (K D ) were estimated following amendment and were around 8 L/kg for compost soil and montmorillonite amended soil and ranged from 1960 to 16,940 L/kg for AC amended soil. The remediation of AFFF impacted soil via immobilisation of PFAS following sorbent amendment with AC is promising as part of an overall remediation strategy. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effects of biochar amendment on geotechnical properties of landfill cover soil.

PubMed

Reddy, Krishna R; Yaghoubi, Poupak; Yukselen-Aksoy, Yeliz

2015-06-01

Biochar is a carbon-rich product obtained when plant-based biomass is heated in a closed container with little or no available oxygen. Biochar-amended soil has the potential to serve as a landfill cover material that can oxidise methane emissions for two reasons: biochar amendment can increase the methane retention time and also enhance the biological activity that can promote the methanotrophic oxidation of methane. Hydraulic conductivity, compressibility and shear strength are the most important geotechnical properties that are required for the design of effective and stable landfill cover systems, but no studies have been reported on these properties for biochar-amended landfill cover soils. This article presents physicochemical and geotechnical properties of a biochar, a landfill cover soil and biochar-amended soils. Specifically, the effects of amending 5%, 10% and 20% biochar (of different particle sizes as produced, size-20 and size-40) to soil on its physicochemical properties, such as moisture content, organic content, specific gravity and pH, as well as geotechnical properties, such as hydraulic conductivity, compressibility and shear strength, were determined from laboratory testing. Soil or biochar samples were prepared by mixing them with 20% deionised water based on dry weight. Samples of soil amended with 5%, 10% and 20% biochar (w/w) as-is or of different select sizes, were also prepared at 20% initial moisture content. The results show that the hydraulic conductivity of the soil increases, compressibility of the soil decreases and shear strength of the soil increases with an increase in the biochar amendment, and with a decrease in biochar particle size. Overall, the study revealed that biochar-amended soils can possess excellent geotechnical properties to serve as stable landfill cover materials. © The Author(s) 2015.

Nitrate removal from agricultural drainage ditch sediments with amendments of organic carbon: Potential for an innovative best management practice

USGS Publications Warehouse

Faust, Derek R.; Kröger, Robert; Miranda, Leandro E.; Rush, Scott A.

2016-01-01

Agricultural fertilizer applications have resulted in loading of nutrients to agricultural drainage ditches in the Lower Mississippi Alluvial Valley. The purpose of this study was to determine effects of dissolved organic carbon (DOC) and particulate organic carbon (POC) amendments on nitrate-nitrogen (NO3−-N) removal from overlying water, pore water, and sediment of an agricultural drainage ditch. Two experiments were conducted. In experiment 1, control (i.e., no amendment), DOC, and POC treatments were applied in laboratory microcosms for time intervals of 3, 7, 14, and 28 days. In experiment 2, control, DOC, and POC treatments were applied in microcosms at C/N ratios of 5:1, 10:1, 15:1, and 20:1. There were statistically significant effects of organic carbon amendments in experiment 1 (F2,71 = 27.1, P < 0.001) and experiment 2 (F2,53 = 39.1, P < 0.001), time (F1,71 = 14.5, P < 0.001) in experiment 1, and C/N ratio (F1,53 = 36.5, P < 0.001) in experiment 2. NO3−-N removal varied from 60 to 100 % in overlying water among all treatments. The lowest NO3−-N removals in experiment 1 were observed in the control at 14 and 28 days, which were significantly less than in DOC and POC 14- and 28-day treatments. In experiment 2, significantly less NO3−-N was removed in overlying water of the control compared to DOC and POC treatments at all C/N ratios. Amendments of DOC and POC made to drainage ditch sediment: (1) increased NO3−-N removal, especially over longer time intervals (14 to 28 days); (2) increased NO3−-N removal, regardless of C/N ratio; and (3) NO3−-N removal was best at a 5:1 C/N ratio. This study provides support for continued investigation on the use of organic carbon amendments as a best management practice for NO3−-N removal in agricultural drainage ditches.

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.

Organic amendments enhance microbial diversity and abundance of functional genes in Australian Soils

NASA Astrophysics Data System (ADS)

Aldorri, Sind; McMillan, Mary; Pereg, Lily

2016-04-01

Food and cash crops play important roles in Australia's economy with black, grey and red clay soil, widely use for growing cotton, wheat, corn and other crops in rotation. While the majority of cotton growers use nitrogen and phosphate fertilizers only in the form of agrochemicals, a few experiment with the addition of manure or composted plant material before planting. We hypothesized that the use of such organic amendments would enhance the soil microbial function through increased microbial diversity and abundance, thus contribute to improved soil sustainability. To test the hypothesis we collected soil samples from two cotton-growing farms in close geographical proximity and with mostly similar production practices other than one grower has been using composted plants as organic amendment and the second farmer uses only agrochemicals. We applied the Biolog Ecoplate system to study the metabolic signature of microbial communities and used qPCR to estimate the abundance of functional genes in the soil. The soil treated with organic amendments clearly showed higher metabolic activity of a more diverse range of carbon sources as well as higher abundance of genes involved in the nitrogen and phosphorous cycles. Since microbes undertake a large number of soil functions, the use of organic amendments can contribute to the sustainability of agricultural soils.

Multi-walled Carbon Nanotubes Reduce Toxicity of Diphenhydramine to Ceriodaphnia dubia in Water and Sediment Exposures.

PubMed

Myer, Mark H; Black, Marsha C

2017-09-01

Multi-walled carbon nanotubes are adsorptive materials that have potential for remediation of organic contaminants in water. Sediment elutriate exposures were undertaken with Ceriodaphnia dubia to compare the toxic effects of diphenhydramine in the presence and absence of sediment and multi-walled carbon nanotubes. In both sediment and solution-only treatments, addition of 0.318 mg/g of carbon nanotubes significantly decreased 48-h mortality relative to control, with a 78.7%-90.1% reduction in treatments with nanotube-amended sediment and 40.7%-53.3% reduction in nanotube-amended water exposures. The greatest degree of relative mortality reduction occurred in sediments containing higher levels of natural organic matter, indicating a potential additive effect.

Nitrogen Amendment Stimulated Decomposition of Maize Straw-Derived Biochar in a Sandy Loam Soil: A Short-Term Study.

PubMed

Lu, Weiwei; Ding, Weixin; Zhang, Junhua; Zhang, Huanjun; Luo, Jiafa; Bolan, Nanthi

2015-01-01

This study examined the effect of nitrogen (N) on biochar stability in relation to soil microbial community as well as biochar labile components using δ13C stable isotope technology. A sandy loam soil under a long-term rotation of C3 crops was amended with biochar produced from maize (a C4 plant) straw in absence (BC0) and presence (BCN) of N and monitored for dynamics of carbon dioxide (CO2) flux, phospholipid fatty acids (PLFAs) profile and dissolved organic carbon (DOC) content. N amendment significantly increased the decomposition of biochar during the first 5 days of incubation (P < 0.05), and the proportions of decomposed biochar carbon (C) were 2.30% and 3.28% in BC0 and BCN treatments, respectively, during 30 days of incubation. The magnitude of decomposed biochar C was significantly (P < 0.05) higher than DOC in biochar (1.75%) and part of relatively recalcitrant biochar C was mineralized in both treatments. N amendment increased soil PLFAs concentration at the beginning of incubation, indicating that microorganisms were N-limited in test soil. Furthermore, N amendment significantly (P < 0.05) increased the proportion of gram-positive (G+) bacteria and decreased that of fungi, while no noticeable changes were observed for gram-negative (G-) bacteria and actinobacteria at the early stage of incubation. Our results indicated that N amendment promoted more efficiently the proliferation of G+ bacteria and accelerated the decomposition of relatively recalcitrant biochar C, which in turn reduced the stability of maize straw-derived biochar in test soil.

Nitrogen Amendment Stimulated Decomposition of Maize Straw-Derived Biochar in a Sandy Loam Soil: A Short-Term Study

PubMed Central

Lu, Weiwei; Ding, Weixin; Zhang, Junhua; Zhang, Huanjun; Luo, Jiafa; Bolan, Nanthi

2015-01-01

This study examined the effect of nitrogen (N) on biochar stability in relation to soil microbial community as well as biochar labile components using δ13C stable isotope technology. A sandy loam soil under a long-term rotation of C3 crops was amended with biochar produced from maize (a C4 plant) straw in absence (BC0) and presence (BCN) of N and monitored for dynamics of carbon dioxide (CO2) flux, phospholipid fatty acids (PLFAs) profile and dissolved organic carbon (DOC) content. N amendment significantly increased the decomposition of biochar during the first 5 days of incubation (P < 0.05), and the proportions of decomposed biochar carbon (C) were 2.30% and 3.28% in BC0 and BCN treatments, respectively, during 30 days of incubation. The magnitude of decomposed biochar C was significantly (P < 0.05) higher than DOC in biochar (1.75%) and part of relatively recalcitrant biochar C was mineralized in both treatments. N amendment increased soil PLFAs concentration at the beginning of incubation, indicating that microorganisms were N-limited in test soil. Furthermore, N amendment significantly (P < 0.05) increased the proportion of gram-positive (G+) bacteria and decreased that of fungi, while no noticeable changes were observed for gram-negative (G−) bacteria and actinobacteria at the early stage of incubation. Our results indicated that N amendment promoted more efficiently the proliferation of G+ bacteria and accelerated the decomposition of relatively recalcitrant biochar C, which in turn reduced the stability of maize straw-derived biochar in test soil. PMID:26192282

77 FR 15042 - Small Diameter Graphite Electrodes From the People's Republic of China: Amended Final Results of...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-14

..., Department of Commerce. DATES: Effective Date: March 14, 2012. SUMMARY: On September 13, 2011, the Department... Jinly Petrochemical Carbon Co., Ltd. (``Fushun Jinly''); Beijing Fangda Carbon Tech Co., Ltd. (``Beijing Fangda''), Fangda Carbon New Material Co., Ltd. (``Fangda Carbon''), Fushun Carbon Co., Ltd. (```Fushun...

Soluble organic carbon and pH of organic amendments affect metal mobility and chemical speciation in mine soils.

PubMed

Pérez-Esteban, Javier; Escolástico, Consuelo; Masaguer, Alberto; Vargas, Carmen; Moliner, Ana

2014-05-01

We evaluated the effects of pH and soluble organic carbon affected by organic amendments on metal mobility to find out the optimal conditions for their application in the stabilization of metals in mine soils. Soil samples (pH 5.5-6.2) were mixed with 0, 30 and 60 th a(-1) of sheep-horse manure (pH 9.4) and pine bark compost (pH 5.7). A single-step extraction procedure was performed using 0.005 M CaCl2 adjusted to pH 4.0-7.0 and metal speciation in soil solution was simulated using NICA-Donnan model. Sheep-horse manure reduced exchangeable metal concentrations (up to 71% Cu, 75% Zn) due to its high pH and degree of maturity, whereas pine bark increased them (32% Cu, 33% Zn). However, at increasing dose and hence pH, sheep-horse manure increased soluble Cu because of higher soluble organic carbon, whereas soluble Cu and organic carbon increased at increasing dose and correspondingly decreasing pH in pine bark and non-amended treatments. Near the native pH of these soils (at pH 5.8-6.3), with small doses of amendments, there was minimum soluble Cu and organic carbon. Pine bark also increased Zn solubility, whereas sheep-horse manure reduced it as soluble Zn always decreased with increasing pH. Sheep-horse manure also reduced the proportion of free metals in soil solution (from 41% to 4% Cu, from 97% to 94% Zn), which are considered to be more bioavailable than organic species. Sheep-horse manure amendment could be efficiently used for the stabilization of metals with low risk of leaching to groundwater at low doses and at relatively low pH, such as the native pH of mine soils. Copyright © 2013 Elsevier Ltd. All rights reserved.

Mercury remediation in wetland sediment using zero-valent iron and granular activated carbon.

PubMed

Lewis, Ariel S; Huntington, Thomas G; Marvin-DiPasquale, Mark C; Amirbahman, Aria

2016-05-01

Wetlands are hotspots for production of toxic methylmercury (MeHg) that can bioaccumulate in the food web. The objective of this study was to determine whether the application of zero-valent iron (ZVI) or granular activated carbon (GAC) to wetland sediment could reduce MeHg production and bioavailability to benthic organisms. Field mesocosms were installed in a wetland fringing Hodgdon Pond (Maine, USA), and ZVI and GAC were applied. Pore-water MeHg concentrations were lower in treated compared with untreated mesocosms; however, sediment MeHg, as well as total Hg (THg), concentrations were not significantly different between treated and untreated mesocosms, suggesting that smaller pore-water MeHg concentrations in treated sediment were likely due to adsorption to ZVI and GAC, rather than inhibition of MeHg production. In laboratory experiments with intact vegetated sediment clumps, amendments did not significantly change sediment THg and MeHg concentrations; however, the mean pore-water MeHg and MeHg:THg ratios were lower in the amended sediment than the control. In the laboratory microcosms, snails (Lymnaea stagnalis) accumulated less MeHg in sediment treated with ZVI or GAC. The study results suggest that both GAC and ZVI have potential for reducing MeHg bioaccumulation in wetland sediment. Copyright © 2015 Elsevier Ltd. All rights reserved.

In situ pilot test for bioremediation of energetic compound-contaminated soil at a former military demolition range site.

PubMed

Jugnia, Louis B; Manno, Dominic; Drouin, Karine; Hendry, Meghan

2018-05-04

Bioremediation was performed in situ at a former military range site to assess the performance of native bacteria in degrading hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and 2,4-dinitrotoluene (2,4-DNT). The fate of these pollutants in soil and soil pore water was investigated as influenced by waste glycerol amendment to the soil. Following waste glycerol application, there was an accumulation of organic carbon that promoted microbial activity, converting organic carbon into acetate and propionate, which are intermediate compounds in anaerobic processes. This augmentation of anaerobic activity strongly correlated to a noticeable reduction in RDX concentrations in the amended soil. Changes in concentrations of RDX in pore water were similar to those observed in the soil suggesting that RDX leaching from the soil matrix, and treatment with waste glycerol, contributed to the enhanced removal of RDX from the water and soil. This was not the case with 2,4-DNT, which was neither found in pore water nor affected by the waste glycerol treatment. Results from saturated conditions and Synthetic Precipitation Leaching Procedure testing, to investigate the environmental fate of 2,4-DNT, indicated that 2,4-DNT found on site was relatively inert and was likely to remain in its current state on the site.

A Combined Field and Laboratory Study on Activated Carbon-Based Thin Layer Capping in a PCB-Contaminated Boreal Lake.

PubMed

Abel, Sebastian; Akkanen, Jarkko

2018-04-17

The in situ remediation of aquatic sediments with activated carbon (AC)-based thin layer capping is a promising alternative to traditional methods, such as sediment dredging. Applying a strong sorbent like AC directly to the sediment can greatly reduce the bioavailability of organic pollutants. To evaluate the method under realistic field conditions, a 300 m 2 plot in the PCB-contaminated Lake Kernaalanjärvi, Finland, was amended with an AC cap (1.6 kgAC/m 2 ). The study lake showed highly dynamic sediment movements over the monitoring period of 14 months. This led to poor retention and rapid burial of the AC cap under a layer of contaminated sediment from adjacent sites. As a result, the measured impact of the AC amendment was low: Both the benthic community structure and PCB bioaccumulation were similar on the plot and in surrounding reference sites. Corresponding follow-up laboratory studies using Lumbriculus variegatus and Chironomus riparius showed that long-term remediation success is possible, even when an AC cap is covered with contaminated sediment. To retain a measurable effectiveness (reduction in contaminant bioaccumulation), a sufficient intensity and depth of bioturbation is required. On the other hand, the magnitude of the adverse effect induced by AC correlated positively with the measured remediation success.

Mercury remediation in wetland sediment using zero-valent iron and granular activated carbon

USGS Publications Warehouse

Lewis, Ariel S.; Huntington, Thomas G.; Marvin-DiPasquale, Mark C.; Amirbahman, Aria

2016-01-01

Wetlands are hotspots for production of toxic methylmercury (MeHg) that can bioaccumulate in the food web. The objective of this study was to determine whether the application of zero-valent iron (ZVI) or granular activated carbon (GAC) to wetland sediment could reduce MeHg production and bioavailability to benthic organisms. Field mesocosms were installed in a wetland fringing Hodgdon Pond (Maine, USA), and ZVI and GAC were applied. Pore-water MeHg concentrations were lower in treated compared with untreated mesocosms; however, sediment MeHg, as well as total Hg (THg), concentrations were not significantly different between treated and untreated mesocosms, suggesting that smaller pore-water MeHg concentrations in treated sediment were likely due to adsorption to ZVI and GAC, rather than inhibition of MeHg production. In laboratory experiments with intact vegetated sediment clumps, amendments did not significantly change sediment THg and MeHg concentrations; however, the mean pore-water MeHg and MeHg:THg ratios were lower in the amended sediment than the control. In the laboratory microcosms, snails (Lymnaea stagnalis) accumulated less MeHg in sediment treated with ZVI or GAC. The study results suggest that both GAC and ZVI have potential for reducing MeHg bioaccumulation in wetland sediment.

Biochar affects carbon composition and stability in soil: a combined spectroscopy-microscopy study

PubMed Central

Hernandez-Soriano, Maria C.; Kerré, Bart; Kopittke, Peter M.; Horemans, Benjamin; Smolders, Erik

2016-01-01

The use of biochar can contribute to carbon (C) storage in soil. Upon addition of biochar, there is a spatial reorganization of C within soil particles, but the mechanisms remain unclear. Here, we used Fourier transformed infrared-microscopy and confocal laser scanning microscopy to examine this reorganization. A silty-loam soil was amended with three different organic residues and with the biochar produced from these residues and incubated for 237 d. Soil respiration was lower in biochar-amended soils than in residue-amended soils. Fluorescence analysis of the dissolved organic matter revealed that biochar application increased a humic-like fluorescent component, likely associated with biochar-C in solution. The combined spectroscopy-microscopy approach revealed the accumulation of aromatic-C in discrete spots in the solid-phase of microaggregates and its co-localization with clay minerals for soil amended with raw residue or biochar.The co-localization of aromatic-C:polysaccharides-C was consistently reduced upon biochar application. We conclude that reduced C metabolism is an important mechanism for C stabilization in biochar-amended soils. PMID:27113269

Biochar affects carbon composition and stability in soil: a combined spectroscopy-microscopy study.

PubMed

Hernandez-Soriano, Maria C; Kerré, Bart; Kopittke, Peter M; Horemans, Benjamin; Smolders, Erik

2016-04-26

The use of biochar can contribute to carbon (C) storage in soil. Upon addition of biochar, there is a spatial reorganization of C within soil particles, but the mechanisms remain unclear. Here, we used Fourier transformed infrared-microscopy and confocal laser scanning microscopy to examine this reorganization. A silty-loam soil was amended with three different organic residues and with the biochar produced from these residues and incubated for 237 d. Soil respiration was lower in biochar-amended soils than in residue-amended soils. Fluorescence analysis of the dissolved organic matter revealed that biochar application increased a humic-like fluorescent component, likely associated with biochar-C in solution. The combined spectroscopy-microscopy approach revealed the accumulation of aromatic-C in discrete spots in the solid-phase of microaggregates and its co-localization with clay minerals for soil amended with raw residue or biochar.The co-localization of aromatic-C:polysaccharides-C was consistently reduced upon biochar application. We conclude that reduced C metabolism is an important mechanism for C stabilization in biochar-amended soils.

Biochar affects carbon composition and stability in soil: a combined spectroscopy-microscopy study

NASA Astrophysics Data System (ADS)

Hernandez-Soriano, Maria C.; Kerré, Bart; Kopittke, Peter M.; Horemans, Benjamin; Smolders, Erik

2016-04-01

The use of biochar can contribute to carbon (C) storage in soil. Upon addition of biochar, there is a spatial reorganization of C within soil particles, but the mechanisms remain unclear. Here, we used Fourier transformed infrared-microscopy and confocal laser scanning microscopy to examine this reorganization. A silty-loam soil was amended with three different organic residues and with the biochar produced from these residues and incubated for 237 d. Soil respiration was lower in biochar-amended soils than in residue-amended soils. Fluorescence analysis of the dissolved organic matter revealed that biochar application increased a humic-like fluorescent component, likely associated with biochar-C in solution. The combined spectroscopy-microscopy approach revealed the accumulation of aromatic-C in discrete spots in the solid-phase of microaggregates and its co-localization with clay minerals for soil amended with raw residue or biochar.The co-localization of aromatic-C:polysaccharides-C was consistently reduced upon biochar application. We conclude that reduced C metabolism is an important mechanism for C stabilization in biochar-amended soils.

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

Relative contributions of mercury bioavailability and microbial growth rate on net methylmercury production by anaerobic mixed cultures

DOE PAGES

Kucharzyk, Katarzyna H.; Deshusses, Marc A.; Porter, Kaitlyn A.; ...

2015-07-17

Monomethylmercury (MeHg) is produced in many aquatic environments by anaerobic microorganisms that take up and methylate inorganic forms of Hg(II). Net methylation of Hg(II) appears to be correlated with factors that affect the activity of the anaerobic microbial community and factors that increase the bioavailability of Hg(II) to these organisms. However, the relative importance of one versus the other is difficult to elucidate even though this information can greatly assist remediation efforts and risk assessments. Here in this study, we investigated the effects of Hg speciation (dissolved Hg and nanoparticulate HgS) and microbial activity on the net production of MeHgmore » using two mixed microbial cultures that were enriched from marine sediments under sulfate reducing conditions. The cultures were amended with dissolved Hg (added as a dissolved nitrate salt) and nanoparticulate HgS, and grown under different carbon substrate concentrations. The results indicated that net mercury methylation was the highest for cultures incubated in the greatest carbon substrate concentration (60 mM) compared to incubations with less carbon (0.6 and 6 mM), regardless of the form of mercury amended. Net MeHg production in cultures exposed to HgS nanoparticles was significantly slower than in cultures exposed to dissolved Hg; however, the difference diminished with slower growing cultures with low carbon addition (0.6 mM). The net Hg methylation rate was found to correlate with sulfate reduction rate in cultures exposed to dissolved Hg, while methylation rate was roughly constant for cultures exposed to nanoparticulate HgS. These results indicated a potential threshold of microbial productivity: below this point net MeHg production was limited by microbial activity, regardless of Hg bioavailability. Lastly, above this threshold of productivity, Hg speciation became a contributing factor towards net MeHg production.« less

Protection from wintertime rainfall reduces nutrient losses and greenhouse gas emissions during the decomposition of poultry and horse manure-based amendments.

PubMed

Maltais-Landry, Gabriel; Neufeld, Katarina; Poon, David; Grant, Nicholas; Nesic, Zoran; Smukler, Sean

2018-04-01

Manure-based soil amendments (herein "amendments") are important fertility sources, but differences among amendment types and management can significantly affect their nutrient value and environmental impacts. A 6-month in situ decomposition experiment was conducted to determine how protection from wintertime rainfall affected nutrient losses and greenhouse gas (GHG) emissions in poultry (broiler chicken and turkey) and horse amendments. Changes in total nutrient concentration were measured every 3 months, changes in ammonium (NH 4 + ) and nitrate (NO 3 - ) concentrations every month, and GHG emissions of carbon dioxide (CO 2 ), methane (CH 4 ), and nitrous oxide (N 2 O) every 7-14 days. Poultry amendments maintained higher nutrient concentrations (except for K), higher emissions of CO 2 and N 2 O, and lower CH 4 emissions than horse amendments. Exposing amendments to rainfall increased total N and NH 4 + losses in poultry amendments, P losses in turkey and horse amendments, and K losses and cumulative N 2 O emissions for all amendments. However, it did not affect CO 2 or CH 4 emissions. Overall, rainfall exposure would decrease total N inputs by 37% (horse), 59% (broiler chicken), or 74% (turkey) for a given application rate (wet weight basis) after 6 months of decomposition, with similar losses for NH 4 + (69-96%), P (41-73%), and K (91-97%). This study confirms the benefits of facilities protected from rainfall to reduce nutrient losses and GHG emissions during amendment decomposition. The impact of rainfall protection on nutrient losses and GHG emissions was monitored during the decomposition of broiler chicken, turkey, and horse manure-based soil amendments. Amendments exposed to rainfall had large ammonium and potassium losses, resulting in a 37-74% decrease in N inputs when compared with amendments protected from rainfall. Nitrous oxide emissions were also higher with rainfall exposure, although it had no effect on carbon dioxide and methane emissions. Overall, this work highlights the benefits of rainfall protection during amendment decomposition to reduce nutrient losses and GHG emissions.

Application of ultrafiltration and stable isotopic amendments to field studies of mercury partitioning to filterable carbon in lake water and overland runoff

USGS Publications Warehouse

Babiarz, Christopher L.; Hurley, J.P.; Krabbenhoft, D.P.; Gilmour, C.; Branfireun, B.A.

2003-01-01

Results from pilot studies on colloidal phase transport of newly deposited mercury in lake water and overland runoff demonstrate that the combination of ultrafiltration, and stable isotope amendment techniques is a viable tool for the study of mercury partitioning to filterable carbon. Ultrafiltration mass balance calculations were generally excellent, averaging 97.3, 96.1 and 99.8% for dissolved organic carbon (DOC), total mercury (HgT), and methylmercury (MeHg), respectively. Sub nanogram per liter quantities of isotope were measurable, and the observed phase distribution from replicate ultrafiltration separations on lake water agreed within 20%. We believe the data presented here are the first published colloidal phase mercury data on lake water and overland runoff from uncontaminated sites. Initial results from pilot-scale lake amendment experiments indicate that the choice of matrix used to dissolve the isotope did not affect the initial phase distribution of the added mercury in the lake. In addition there was anecdotal evidence that native MeHg was either recently produced in the system, or at a minimum, that this 'old' MeHg partitions to the same subset of DOC that binds the amended mercury. Initial results from pilot-scale overland runoff experiments indicate that less than 20% of newly deposited mercury was transported in the filterable fraction (<0.7 ??m). There is some indication of colloidal phase enrichment of mercury in runoff compared to the phase distribution of organic carbon, but the mechanism of this enrichment is unclear. The phase distribution of newly deposited mercury can differ from that of organic carbon and native mercury, suggesting that the quality of the carbon (available ligands), not the quantity of carbon, regulates partitioning. Further characterization of DOC is needed to clarify the underlying mechanisms. ?? 2002 Elsevier Science B.V. All rights reserved.

Soil Organic Carbon Loss: An Overlooked Factor in the Carbon Sequestration Potential of Enhanced Mineral Weathering

NASA Astrophysics Data System (ADS)

Dietzen, Christiana; Harrison, Robert

2016-04-01

Weathering of silicate minerals regulates the global carbon cycle on geologic timescales. Several authors have proposed that applying finely ground silicate minerals to soils, where organic acids would enhance the rate of weathering, could increase carbon uptake and mitigate anthropogenic CO2 emissions. Silicate minerals such as olivine could replace lime, which is commonly used to remediate soil acidification, thereby sequestering CO2 while achieving the same increase in soil pH. However, the effect of adding this material on soil organic matter, the largest terrestrial pool of carbon, has yet to be considered. Microbial biomass and respiration have been observed to increase with decreasing acidity, but it is unclear how long the effect lasts. If the addition of silicate minerals promotes the loss of soil organic carbon through decomposition, it could significantly reduce the efficiency of this process or even create a net carbon source. However, it is possible that this initial flush of microbial activity may be compensated for by additional organic matter inputs to soil pools due to increases in plant productivity under less acidic conditions. This study aimed to examine the effects of olivine amendments on soil CO2 flux. A liming treatment representative of typical agricultural practices was also included for comparison. Samples from two highly acidic soils were split into groups amended with olivine or lime and a control group. These samples were incubated at 22°C and constant soil moisture in jars with airtight septa lids. Gas samples were extracted periodically over the course of 2 months and change in headspace CO2 concentration was determined. The effects of enhanced mineral weathering on soil organic matter have yet to be addressed by those promoting this method of carbon sequestration. This project provides the first data on the potential effects of enhanced mineral weathering in the soil environment on soil organic carbon pools.

Enhanced rice production but greatly reduced carbon emission following biochar amendment in a metal-polluted rice paddy.

PubMed

Zhang, Afeng; Bian, Rongjun; Li, Lianqing; Wang, Xudong; Zhao, Ying; Hussain, Qaiser; Pan, Genxing

2015-12-01

Soil amendment of biochar (BSA) had been shown effective for mitigating greenhouse gas (GHG) emission and alleviating metal stress to plants and microbes in soil. It has not yet been addressed if biochar exerts synergy effects on crop production, GHG emission, and microbial activity in metal-polluted soils. In a field experiment, biochar was amended at sequential rates at 0, 10, 20, and 40 t ha(-1), respectively, in a cadmium- and lead-contaminated rice paddy from the Tai lake Plain, China, before rice cropping in 2010. Fluxes of soil carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) were monitored using a static chamber method during the whole rice growing season (WRGS) of 2011. BSA significantly reduced soil CaCl2 extractable pool of Cd, and DTPA extractable pool of Cd and Pb. As compared to control, soil CO2 emission under BSA was observed to have no change at 10 t ha(-1) but decreased by 16-24% at 20 and 40 t ha(-1). In a similar trend, BSA at 20 and 40 t ha(-1) increased rice yield by 25-26% and thus enhanced ecosystem CO2 sequestration by 47-55% over the control. Seasonal total N2O emission was reduced by 7.1, 30.7, and 48.6% under BSA at 10, 20, and 40 t ha(-1), respectively. Overall, a net reduction in greenhouse gas balance (NGHGB) by 53.9-62.8% and in greenhouse gas intensity (GHGI) by 14.3-28.6% was observed following BSA at 20 and 40 t ha(-1). The present study suggested a great potential of biochar to enhancing grain yield while reducing carbon emission in metal-polluted rice paddies.

Do plant-based amendments improve soil physiochemical and microbiological properties and plant growth in dryland ecosystems?

NASA Astrophysics Data System (ADS)

Kneller, Tayla; Harris, Richard; Muñoz-Rojas, Miriam

2017-04-01

Background Land intensive practices including mining have contributed to the degradation of landscapes globally. Current challenges in post-mine restoration revolve around the use of substrates poor in organic materials (e.g. overburden and waste rock) and lack of original topsoil which may result in poor seedling recruitment and in later stages in soil nutrient deficiency, metal toxicity, decreased microbial activity and high salinity (Bateman et al., 2016; Muñoz-Rojas et al., 2016). Despite continuous efforts and advances we have not proportionally advanced our capability to successfully restore these landscapes following mining. Recent attempts to improve plant establishment in arid zone restoration programs have included the application of plant based amendments to soil profiles. This approach usually aims to accelerate soil reconstruction via improvement of soil aggregate stability and increase of soil organic carbon, and water holding capacity. Whilst a significant amount of recent research has focused on the application of such amendments, studies on the potential application of plant based materials to recover soil functionality and re-establish plant communities in post-mined landscapes in arid regions are limited. Here we will discuss our work investigating the application of a plant based amendment on soil substrates commonly used in post mining restoration in the Pilbara region, Western Australia. Methodology The study was conducted in a glasshouse facility where environmental conditions were continuously monitored. Using two growth materials (topsoil and waste rock) and a plant based amendment (dry biomass of the most common grass in the Pilbara, Triodia wiseana) five different treatments were tested. Treatments consisted of control soil treatments (topsoil, waste and a mixture of the former soil types (mixture)) and two amended soil treatments (waste amended and mixture amended). Additionally, three different vegetation communities were studies, these include Triodia wiseana, Triodia wiseana and Acacia ancistrocarpa and a combination of the former species with Grevillia wickhamii. Pots were filled with soil materials and allocated plant community treatments. Plant growth and morphology, soil physiochemical (pH, electrical conductivity, N and organic C) and biological (microbial activity) properties were measured after 12 months to assess the suitability of the amendments. Results Our results have demonstrated a general decline in plant survival over the duration of 12 months, where pots with amended mine soils displaying the lowest survival rates compared to the topsoil. However, soil microbial activity of pots containing amendments was greater than those without, although there was no significant difference in microbial activity across vegetation communities (p < 0.05). References Bateman A, Lewandrowski W, Stevens JC, Muñoz-Rojas M. 2016. Ecophysiological Indicators to Assess Drought Responses of Arid Zone Native Seedlings in Reconstructed Soils. Land Degradation & Development. published online. DOI:10.1002/ldr.2660 Muñoz-Rojas M, Erickson TE, Dixon KW, Merritt DJ. 2016. Soil quality indicators to assess functionality of restored soils in degraded semiarid ecosystems. Restoration Ecology 24, 43-52. DOI: 10.1111/rec.12368

Effects of organic carbon sequestration strategies on soil enzymatic activities

NASA Astrophysics Data System (ADS)

Puglisi, E.; Suciu, N.; Botteri, L.; Ferrari, T.; Coppolecchia, D.; Trevisan, M.; Piccolo, A.

2009-04-01

Greenhouse gases emissions can be counterbalanced with proper agronomical strategies aimed at sequestering carbon in soils. These strategies must be tested not only for their ability in reducing carbon dioxide emissions, but also for their impact on soil quality: enzymatic activities are related to main soil ecological quality, and can be used as early and sensitive indicators of alteration events. Three different strategies for soil carbon sequestration were studied: minimum tillage, protection of biodegradable organic fraction by compost amendment and oxidative polimerization of soil organic matter catalyzed by biometic porfirins. All strategies were compared with a traditional agricultural management based on tillage and mineral fertilization. Experiments were carried out in three Italian soils from different pedo-climatic regions located respectively in Piacenza, Turin and Naples and cultivated with maize or wheat. Soil samples were taken for three consecutive years after harvest and analyzed for their content in phosphates, ß-glucosidase, urease and invertase. An alteration index based on these enzymatic activities levels was applied as well. The biomimetic porfirin application didn't cause changes in enzymatic activities compared to the control at any treatment or location. Enzymatic activities were generally higher in the minimum tillage and compost treatment, while differences between location and date of samplings were limited. Application of the soil alteration index based on enzymatic activities showed that soils treated with compost or subjected to minimum tillage generally have a higher biological quality. The work confirms the environmental sustainability of the carbon sequestering agronomical practices studied.

Terrestrial Carbon Sequestration: Analysis of Terrestrial Carbon Sequestration at Three Contaminated Sites Remediated and Revitalized with Soil Amendments

EPA Pesticide Factsheets

This paper provides EPA's analysis of the data to determine carbon sequestration rates at three diverse sites that differ in geography/location, weather, soil properties, type of contamination, and age.

Use of Pyrogenic Carbon Geosorbents to Decrease the Mobility and Bioavailability of Pharmaceuticals in the Soil-Water-Biota Continuum

NASA Astrophysics Data System (ADS)

Liu, Cheng-Hua; Zhang, Yingjie; Bhalsod, Gemini; Chuang, Ya-Hui; Boyd, Stephen; Teppen, Brian; Tiedje, James; Li, Hui; Zhang, Wei

2016-04-01

Pharmaceuticals are emerging contaminants widely detected in soil and water environments, and concerns are mounting over their potential impact on human and ecosystem health. In particular, overuse of antibiotics (an important group of pharmaceuticals) in human medicine and animal agriculture and rapid emergence of antibiotic resistant bacteria on a global scale are threatening the health of humans, animals, and the environment. We have investigated interactions of pharmaceuticals with pyrogenic carbon geosorbents (e.g., biohar and activated carbon), bacteria, and vegetable crops in order to better understand sorption, uptake, and translocation of pharmaceuticals in the soil-water-biota continuum. Sorption of antibiotics by biochars was studied to assess the effect of biochar soil amendment in reducing the transport and bioavailability of antibiotics. Pyrogenic carbonaceous materials such as biochars and activated carbon had strong sorption capacities for antibiotics, and drastically lowed the uptake of antibiotics by an Escherichia coli, therefore demonstrating soil amendment with pyrogenic carbon geosorbents as an effective remediation strategy to reduce antibiotic transport and selection pressure for antibiotic resistant bacteria. Additionally, because consuming pharmaceutical-tainted food is a direct human exposure pathway, it is critical to investigate the residue levels of pharmaceuticals in food crops grown in contaminated soils or irrigated with reclaimed water. Therefore, we have studied the uptake and accumulations of pharmaceuticals in greenhouse-grown lettuce under overhead or surface irrigations. Preliminary results indicate that pharmaceuticals of large molecular weight and low water solubility had greater concentrations in lettuce shoots under overhead irrigation than surface irrigation. Pharmaceuticals of low molecular weight and high water solubility are less clearly influenced by irrigation methods. These results implies that irrigation scheme needs to be optimized when using the reclaimed water for crop irrigation. In summary, scientifically-sound soil and water management practices are needed to minimize the transfer of pharmaceuticals from soil and water to crops and microorganisms.

Soil amendment using poplar woodchips to enhance the treatment of wastewater-originated nutrients.

PubMed

Meffe, Raffaella; de Miguel, Ángel; Martínez Hernández, Virtudes; Lillo, Javier; de Bustamante, Irene

2016-09-15

Vegetation filters, a nature based wastewater regeneration technology, have been reported as a feasible solution for small municipalities and scattered populations with limited access to sewage networks. However even when such a treatment is properly planned, the leaching of contaminants through the unsaturated zone may occur. The amendment of soil with a readily-labile source of carbon is supposed to ameliorate the removal of contaminants by stimulating microbial activity and enhancing sorption processes. In this study, lab-scale leaching column experiments were carried out to explore if the addition of woodchips to the soil could be a feasible strategy to be integrated in a vegetation filter. Two different types of arrangement of soil and woodchips layers were tested. The soil was collected from an operating vegetation filter treating wastewater of an office building characterised by a high nutrient load. Daily pulse of synthetic wastewater were applied into the columns and effluent samples were collected and analyzed for major ions, total nitrogen (NT), total phosphorous (PT) and chemical oxygen demand (COD). By the end of the experiment, NT, NO3-N and PT soil contents were also measured. Results indicate that amendments with woodchips enhance the elimination of wastewater-originated contaminants. NT removal in the columns with woodchips reaches a value of 99.4%. The main processes responsible for this elimination are NH4-N sorption and nitrification/denitrification. This latter fostered by the reduced redox conditions due to the enhanced microbial activity. High removal of PT (99%) is achieved independently of the woodchips presence due to retention and/or precipitation phenomena. The COD removal efficiency is not affected by the presence of the woodchips. The leaching of organic carbon occurs only during the experimental start-up period. Copyright © 2016 Elsevier Ltd. All rights reserved.

Superfund Record of Decision (EPA Region 5): Enviro-Chem (Northside Sanitary Landfill), Zionsville, IN. (First remedial action), (Amendment), June 1991. Final report

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

Not Available

The Enviro-chem site is a former waste recovery/reclamation/brokerage facility in Boone County, Indiana. Adjacent to the site is another Superfund site, the Northside Sanitary Landfill (NSL) which, prior to the Record of Decision (ROD) amendment, was to be remediated in a combined remedy for both sites. Land use in the area is agricultural and residential to the north and west. In May 1982, the State ordered Enviro-Chem to close and environmentally secure the site because it failed to reduce hazardous waste inventories. Subsequently, two emergency removal actions were conducted to remove the major sources of contamination. The ROD amends themore » 1987 ROD and provides a comprehensive site remedy for the Enviro-Chem site addressing source control instead of ground water remediation. The primary contaminants of concern affecting the soil are VOCs including PCE, TCE, toluene; and other organics including phenols. The amended remedial action for the site includes treating contaminated soil onsite using soil vapor extraction with a granulated activated carbon system to control the extracted vapor and implementing a contingent remedy for a subsurface ground water collection and treatment system.« less

Dissolved inorganic carbon enhanced growth, nutrient uptake, and lipid accumulation in wastewater grown microalgal biofilms.

PubMed

Kesaano, Maureen; Gardner, Robert D; Moll, Karen; Lauchnor, Ellen; Gerlach, Robin; Peyton, Brent M; Sims, Ronald C

2015-03-01

Microalgal biofilms grown to evaluate potential nutrient removal options for wastewaters and feedstock for biofuels production were studied to determine the influence of bicarbonate amendment on their growth, nutrient uptake capacity, and lipid accumulation after nitrogen starvation. No significant differences in growth rates, nutrient removal, or lipid accumulation were observed in the algal biofilms with or without bicarbonate amendment. The biofilms possibly did not experience carbon-limited conditions because of the large reservoir of dissolved inorganic carbon in the medium. However, an increase in photosynthetic rates was observed in algal biofilms amended with bicarbonate. The influence of bicarbonate on photosynthetic and respiration rates was especially noticeable in biofilms that experienced nitrogen stress. Medium nitrogen depletion was not a suitable stimulant for lipid production in the algal biofilms and as such, focus should be directed toward optimizing growth and biomass productivities to compensate for the low lipid yields and increase nutrient uptake. Copyright © 2015 Elsevier Ltd. All rights reserved.

Microbially-accelerated consolidation of oil sands tailings. Pathway I: changes in porewater chemistry

PubMed Central

Siddique, Tariq; Kuznetsov, Petr; Kuznetsova, Alsu; Arkell, Nicholas; Young, Rozlyn; Li, Carmen; Guigard, Selma; Underwood, Eleisha; Foght, Julia M.

2014-01-01

Dispersed clay particles in mine tailings and soft sediments remain suspended for decades, hindering consolidation and challenging effective management of these aqueous slurries. Current geotechnical engineering models of self-weight consolidation of tailings do not consider microbial contribution to sediment behavior, however, here we show that microorganisms indigenous to oil sands tailings change the porewater chemistry and accelerate consolidation of oil sands tailings. A companion paper describes the role of microbes in alteration of clay chemistry in tailings. Microbial metabolism in mature fine tailings (MFT) amended with an organic substrate (hydrolyzed canola meal) produced methane (CH4) and carbon dioxide (CO2). Dissolution of biogenic CO2 lowered the pH of amended MFT to pH 6.4 vs. unamended MFT (pH 7.7). About 12% more porewater was recovered from amended than unamended MFT during 2 months of active microbial metabolism, concomitant with consolidation of tailings. The lower pH in amended MFT dissolved carbonate minerals, thereby releasing divalent cations including calcium (Ca2+) and magnesium (Mg2+) and increasing bicarbonate (HCO−3) in porewater. The higher concentrations increased the ionic strength of the porewater, in turn reducing the thickness of the diffuse double layer (DDL) of clay particles by reducing the surface charge potential (repulsive forces) of the clay particles. The combination of these processes accelerated consolidation of oil sands tailings. In addition, ebullition of biogenic gases created transient physical channels for release of porewater. In contrast, saturating the MFT with non-biogenic CO2 had little effect on consolidation. These results have significant implications for management and reclamation of oil sands tailings ponds and broad importance in anaerobic environments such as contaminated harbors and estuaries containing soft sediments rich in clays and organics. PMID:24711805

Microbially-accelerated consolidation of oil sands tailings. Pathway I: changes in porewater chemistry.

PubMed

Siddique, Tariq; Kuznetsov, Petr; Kuznetsova, Alsu; Arkell, Nicholas; Young, Rozlyn; Li, Carmen; Guigard, Selma; Underwood, Eleisha; Foght, Julia M

2014-01-01

Dispersed clay particles in mine tailings and soft sediments remain suspended for decades, hindering consolidation and challenging effective management of these aqueous slurries. Current geotechnical engineering models of self-weight consolidation of tailings do not consider microbial contribution to sediment behavior, however, here we show that microorganisms indigenous to oil sands tailings change the porewater chemistry and accelerate consolidation of oil sands tailings. A companion paper describes the role of microbes in alteration of clay chemistry in tailings. Microbial metabolism in mature fine tailings (MFT) amended with an organic substrate (hydrolyzed canola meal) produced methane (CH4) and carbon dioxide (CO2). Dissolution of biogenic CO2 lowered the pH of amended MFT to pH 6.4 vs. unamended MFT (pH 7.7). About 12% more porewater was recovered from amended than unamended MFT during 2 months of active microbial metabolism, concomitant with consolidation of tailings. The lower pH in amended MFT dissolved carbonate minerals, thereby releasing divalent cations including calcium (Ca(2+)) and magnesium (Mg(2+)) and increasing bicarbonate (HCO(-) 3) in porewater. The higher concentrations increased the ionic strength of the porewater, in turn reducing the thickness of the diffuse double layer (DDL) of clay particles by reducing the surface charge potential (repulsive forces) of the clay particles. The combination of these processes accelerated consolidation of oil sands tailings. In addition, ebullition of biogenic gases created transient physical channels for release of porewater. In contrast, saturating the MFT with non-biogenic CO2 had little effect on consolidation. These results have significant implications for management and reclamation of oil sands tailings ponds and broad importance in anaerobic environments such as contaminated harbors and estuaries containing soft sediments rich in clays and organics.

78 FR 65354 - Notice of Intent To Prepare an Environmental Impact Statement for the Proposed Lobos CO2

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-31

... Pipeline Project in Arizona and New Mexico and Amend the Rio Puerco, Roswell, and Socorro Resource... analyze the proposed Lobos carbon dioxide (CO 2 ) Pipeline Project and consider amendments to the Roswell...

Assessment of field-related influences on polychlorinated biphenyl exposures and sorbent amendment using polychaete bioassays and passive sampler measurements

USGS Publications Warehouse

Janssen, E.M.; Oen, A.M.; Luoma, S.N.; Luthy, R.G.

2011-01-01

Field-related influences on polychlorinated biphenyl (PCB) exposure were evaluated by employing caged deposit-feeders, Neanthes arenaceodentata, along with polyoxymethylene (POM) samplers using parallel in situ and ex situ bioassays with homogenized untreated or activated carbon (AC) amended sediment. The AC amendment achieved a remedial efficiency in reducing bioaccumulation by 90% in the laboratory and by 44% in the field transplants. In situ measurements showed that PCB uptake by POM samplers was greater for POM placed in the surface sediment compared with the underlying AC amendment, suggesting that tidal exchange of surrounding material with similar PCB availability as untreated sediment was redeposited in the cages. Polychlorinated biphenyls bioaccumulation with caged polychaetes from untreated sediment was half as large under field conditions compared with laboratory conditions. A biodynamic model was used to confirm and quantify the different processes that could have influenced these results. Three factors appeared most influential in the bioassays: AC amendment significantly reduces bioavailability under laboratory and field conditions; sediment deposition within test cages in the field partially masks the remedial benefit of underlying AC-amended sediment; and deposit-feeders exhibit less PCB uptake from untreated sediment when feeding is reduced. Ex situ and in situ experiments inevitably show some differences that are associated with measurement methods and effects of the environment. Parallel ex situ and in situ bioassays, passive sampler measurements, and quantifying important processes with a model can tease apart these field influences. ?? 2010 SETAC.

Immobilization of lead in a Korean military shooting range soil using eggshell waste: an integrated mechanistic approach.

PubMed

Ahmad, Mahtab; Hashimoto, Yohey; Moon, Deok Hyun; Lee, Sang Soo; Ok, Yong Sik

2012-03-30

This study evaluated the effectiveness of eggshell and calcined eggshell on lead (Pb) immobilization in a shooting range soil. Destructive and non-destructive analytical techniques were employed to determine the mechanism of Pb immobilization. The 5% additions of eggshell and calcined eggshell significantly decreased the TCLP-Pb concentration by 68.8% due mainly to increasing soil pH. Eggshell and calcined-eggshell amendments decreased the exchangeable Pb fraction to ≈ 1% of the total Pb in the soil, while the carbonate-associated Pb fraction was increased to 40.0-47.1% at >15% application rates. The thermodynamic modeling on Pb speciation in the soil solution predicted the precipitation of Pb-hydroxide [Pb(OH)(2)] in soils amended with eggshell and calcined eggshell. The SEM-EDS, XAFS and elemental dot mapping revealed that Pb in soil amended with calcined eggshell was associated with Si and Ca, and may be immobilized by entrapping into calcium-silicate-hydrate. Comparatively, in the soil amended with eggshell, Pb was immobilized via formation of Pb-hydroxide or lanarkite [Pb(2)O(SO(4))]. Applications of amendments increased activities of alkaline phosphatase up to 3.7 times greater than in the control soil. The use of eggshell amendments may have potential as an integrated remediation strategy that enables Pb immobilization and soil biological restoration in shooting range soils. Copyright © 2012 Elsevier B.V. All rights reserved.

Effects of the amendment of biochars and carbon nanotubes on the bioavailability of hexabromocyclododecanes (HBCDs) in soil to ecologically different species of earthworms.

PubMed

Li, Bing; Zhu, Hongkai; Sun, Hongwen; Xu, Jiayao

2017-03-01

Biochar is a promising material used in soil amendment and carbon nanotubes may enter soil due to its increasing application. These carbonaceous materials may change the bioavailability of pollutants in soil. In this concern, 0.5% w/w multi-walled carbon nanotubes (MWCNTs) and 3 corn-straw biochars acquired at different pyrolyzing temperatures were used in soil amendment and their influences on the bioavailability of hexabromocyclododecanes (HBCDs), a brominated flame retardant, to 2 ecologically different earthworm species were studied. The amendment of 4 carbonaceous materials all reduced the bioaccumulation of HBCDs in earthworms by 18.2%-67.3%, which varied depending on the type of carbonaceous materials and the pyrolyzing temperature of biochars. The reduction in HBCDs uptake by Eisenia fetida (an epigeic species) was greater than by Metaphire guillelmi (an anecic species). The 2 earthworm species both showed bioaccumulative selectivity on certain HBCD diastereoisomer and enantiomer in the amended soils, which was similar to that in the control soil. Moreover, Tenax-assisted HBCDs desorption test was carried out for the simulation of their bioavailability. The rapid desorption fraction (F rap ), total desorption (15 d), and 24 h desorption all correlated well with the uptake of HBCDs in the earthworms, suggesting that the 24 h-desorption, due to its easy availability, can be a good proxy to predict the bioavailability of HBCDs to earthworms in soil. Copyright © 2016. Published by Elsevier Ltd.

Toxicity of iron oxide nanoparticles to grass litter decomposition in a sandy soil

NASA Astrophysics Data System (ADS)

Rashid, Muhammad Imtiaz; Shahzad, Tanvir; Shahid, Muhammad; Imran, Muhammad; Dhavamani, Jeyakumar; Ismail, Iqbal M. I.; Basahi, Jalal M.; Almeelbi, Talal

2017-02-01

We examined time-dependent effect of iron oxide nanoparticles (IONPs) at a rate of 2000 mg kg-1 soil on Cynodon dactylon litter (3 g kg-1) decomposition in an arid sandy soil. Overall, heterotrophic cultivable bacterial and fungal colonies, and microbial biomass carbon were significantly decreased in litter-amended soil by the application of nanoparticles after 90 and 180 days of incubation. Time dependent effect of nanoparticles was significant for microbial biomass in litter-amended soil where nanoparticles decreased this variable from 27% after 90 days to 49% after 180 days. IONPs decreased CO2 emission by 28 and 30% from litter-amended soil after 90 and 180 days, respectively. These observations indicated that time-dependent effect was not significant on grass-litter carbon mineralization efficiency. Alternatively, nanoparticles application significantly reduced mineral nitrogen content in litter-amended soil in both time intervals. Therefore, nitrogen mineralization efficiency was decreased to 60% after 180 days compared to that after 90 days in nanoparticles grass-litter amended soil. These effects can be explained by the presence of labile Fe in microbial biomass after 180 days in nanoparticles amendment. Hence, our results suggest that toxicity of IONPs to soil functioning should consider before recommending their use in agro-ecosystems.

Biochar: A synthesis of its agronomic impact beyond carbon sequestration

USDA-ARS?s Scientific Manuscript database

Biochar has been recently heralded as an amendment to revitalize degraded soils, improve soil carbon sequestration, increase agronomic productivity and enter into future carbon trading markets. However, scientific and economic technicalities may limit the ability of biochar to consistently deliver o...

Long-term Priming-induced Changes in Permafrost Soil Organic Matter Decomposition

NASA Astrophysics Data System (ADS)

Pegoraro, E.; Bracho, R. G.; Schuur, E.

2016-12-01

Warming of tundra ecosystems due to climate change is predicted to thaw permafrost and increase plant biomass and litter input to soil. Additional input of easily decomposable carbon can stimulate microbial activity, consequently increasing soil organic matter decomposition rates. This phenomenon, known as the priming effect, can exacerbate the effects of climate change by releasing more CO2 from permafrost soils; however, the extent to which it could decrease soil carbon stocks in the Arctic is unknown. Most priming incubation studies are conducted for a short period of time, making it difficult to assess if priming is a short-term phenomenon, or could persist over the long-term. We incubated permafrost soil from a moist acidic tundra site in Healy, Alaska for 456 days at 15° C. Soil from surface and deep layers were amended with three pulses of uniformly 13C labeled glucose, a fast decomposing substrate, every 152 days. We also quantified the proportion of old carbon respired by measuring 14CO2. Substrate addition resulted in higher respiration rates in glucose amended soils; however, positive priming was only observed in deep layers, where on average 9%, 57%, and 25% more soil-derived C was respired at 45-55, 65-75, and 75-85 cm depth increments for the duration of the experiment. This suggests that microbes in deep layers are limited in energy, and the addition of easily decomposable carbon increases native soil organic matter decomposition.

Fertilization increases paddy soil organic carbon density.

PubMed

Wang, Shao-xian; Liang, Xin-qiang; Luo, Qi-xiang; Fan, Fang; Chen, Ying-xu; Li, Zu-zhang; Sun, Huo-xi; Dai, Tian-fang; Wan, Jun-nan; Li, Xiao-jun

2012-04-01

Field experiments provide an opportunity to study the effects of fertilization on soil organic carbon (SOC) sequestration. We sampled soils from a long-term (25 years) paddy experiment in subtropical China. The experiment included eight treatments: (1) check, (2) PK, (3) NP, (4) NK, (5) NPK, (6) 7F:3M (N, P, K inorganic fertilizers+30% organic N), (7) 5F:5M (N, P, K inorganic fertilizers+50% organic N), (8) 3F:7M (N, P, K inorganic fertilizers+70% organic N). Fertilization increased SOC content in the plow layers compared to the non-fertilized check treatment. The SOC density in the top 100 cm of soil ranged from 73.12 to 91.36 Mg/ha. The SOC densities of all fertilizer treatments were greater than that of the check. Those treatments that combined inorganic fertilizers and organic amendments had greater SOC densities than those receiving only inorganic fertilizers. The SOC density was closely correlated to the sum of the soil carbon converted from organic amendments and rice residues. Carbon sequestration in paddy soils could be achieved by balanced and combined fertilization. Fertilization combining both inorganic fertilizers and organic amendments is an effective sustainable practice to sequestrate SOC.

Fertilization increases paddy soil organic carbon density*

PubMed Central

Wang, Shao-xian; Liang, Xin-qiang; Luo, Qi-xiang; Fan, Fang; Chen, Ying-xu; Li, Zu-zhang; Sun, Huo-xi; Dai, Tian-fang; Wan, Jun-nan; Li, Xiao-jun

2012-01-01

Field experiments provide an opportunity to study the effects of fertilization on soil organic carbon (SOC) sequestration. We sampled soils from a long-term (25 years) paddy experiment in subtropical China. The experiment included eight treatments: (1) check, (2) PK, (3) NP, (4) NK, (5) NPK, (6) 7F:3M (N, P, K inorganic fertilizers+30% organic N), (7) 5F:5M (N, P, K inorganic fertilizers+50% organic N), (8) 3F:7M (N, P, K inorganic fertilizers+70% organic N). Fertilization increased SOC content in the plow layers compared to the non-fertilized check treatment. The SOC density in the top 100 cm of soil ranged from 73.12 to 91.36 Mg/ha. The SOC densities of all fertilizer treatments were greater than that of the check. Those treatments that combined inorganic fertilizers and organic amendments had greater SOC densities than those receiving only inorganic fertilizers. The SOC density was closely correlated to the sum of the soil carbon converted from organic amendments and rice residues. Carbon sequestration in paddy soils could be achieved by balanced and combined fertilization. Fertilization combining both inorganic fertilizers and organic amendments is an effective sustainable practice to sequestrate SOC. PMID:22467369

Fungi, bacteria and soil pH: the oxalate-carbonate pathway as a model for metabolic interaction.

PubMed

Martin, Gaëtan; Guggiari, Matteo; Bravo, Daniel; Zopfi, Jakob; Cailleau, Guillaume; Aragno, Michel; Job, Daniel; Verrecchia, Eric; Junier, Pilar

2012-11-01

The oxalate-carbonate pathway involves the oxidation of calcium oxalate to low-magnesium calcite and represents a potential long-term terrestrial sink for atmospheric CO(2). In this pathway, bacterial oxalate degradation is associated with a strong local alkalinization and subsequent carbonate precipitation. In order to test whether this process occurs in soil, the role of bacteria, fungi and calcium oxalate amendments was studied using microcosms. In a model system with sterile soil amended with laboratory cultures of oxalotrophic bacteria and fungi, the addition of calcium oxalate induced a distinct pH shift and led to the final precipitation of calcite. However, the simultaneous presence of bacteria and fungi was essential to drive this pH shift. Growth of both oxalotrophic bacteria and fungi was confirmed by qPCR on the frc (oxalotrophic bacteria) and 16S rRNA genes, and the quantification of ergosterol (active fungal biomass) respectively. The experiment was replicated in microcosms with non-sterilized soil. In this case, the bacterial and fungal contribution to oxalate degradation was evaluated by treatments with specific biocides (cycloheximide and bronopol). Results showed that the autochthonous microflora oxidized calcium oxalate and induced a significant soil alkalinization. Moreover, data confirmed the results from the model soil showing that bacteria are essentially responsible for the pH shift, but require the presence of fungi for their oxalotrophic activity. The combined results highlight that the interaction between bacteria and fungi is essential to drive metabolic processes in complex environments such as soil. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

76 FR 65497 - Certain Hot-Rolled Carbon Steel Flat Products From India: Amended Final Results of Countervailing...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-21

... DEPARTMENT OF COMMERCE International Trade Administration [C-533-821] Certain Hot-Rolled Carbon...-rolled carbon steel flat products (HRCS) from India covering the January 1, 2006, through December 31... Certain Hot-Rolled Carbon Steel Flat Products from India: Final Results of Countervailing Duty...

Assessing the use of composts from multiple sources based on the characteristics of carbon mineralization in soil.

PubMed

Zhang, Xu; Zhao, Yue; Zhu, Longji; Cui, Hongyang; Jia, Liming; Xie, Xinyu; Li, Jiming; Wei, Zimin

2017-12-01

In order to improve soil quality, reduce wastes and mitigate climate change, it is necessary to understand the balance between soil organic carbon (SOC) accumulation and depletion under different organic waste compost amended soils. The effects of proportion (5%, 15%, 30%), compost type (sewage sludge (SS), tomato stem waste (TSW), municipal solid waste (MSW), kitchen waste (KW), cabbage waste (CW), peat (P), chicken manure (CM), dairy cattle manure (DCM)) and the black soil (CK). Their initial biochemical composition (carbon, nitrogen, C:N ratio) on carbon (C) mineralization in soil amended compost have been investigated. The CO 2 -C production of different treatments were measured to indicate the levels of carbon (C) mineralization during 50d of laboratory incubation. And the one order E model (M1E) was used to quantify C mineralization kinetics. The results demonstrated that the respiration and C mineralization of soil were promoted by amending composts. The C mineralization ability increased when the percentage of compost added to the soil also increased and affected by compost type in the order CM>KW, CW>SS, DCM, TSW>MSW, P>CK at the same amended level. Based on the values of C 0 and k 1 from M1E model, a management method in agronomic application of compost products to the precise fertilization was proposed. The SS, DCM and TSW composts were more suitable in supplying fertilizer to the plant. Otherwise, The P and MSW composts can serve the purpose of long-term nutrient retention, whereas the CW and KW composts could be used as soil remediation agent. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of dolomite and biochar addition on N2O and CO2 emissions from acidic tea field soil

PubMed Central

Win, Khin Thuzar; Shibata, Akira; Yamamoto, Akinori; Sano, Tomohito; Hirono, Yuhei

2018-01-01

A laboratory study was conducted to study the effects of liming and different biochar amendments on N2O and CO2 emissions from acidic tea field soil. The first experiment was done with three different rates of N treatment; N 300 (300 kg N ha-1), N 600 (600 kg N ha-1) and N 900 (900 kg N ha-1) and four different rates of bamboo biochar amendment; 0%, 0.5%, 1% and 2% biochar. The second experiment was done with three different biochars at a rate of 2% (rice husk, sawdust, and bamboo) and a control and lime treatment (dolomite) and control at two moisture levels (50% and 90% water filled pore space (WFPS)). The results showed that dolomite and biochar amendment significantly increased soil pH. However, only biochar amendment showed a significant increase in total carbon (C), C/N (the ratio of total carbon and total nitrogen), and C/IN ratio (the ratio of total carbon and inorganic nitrogen) at the end of incubation. Reduction in soil NO3--N concentration was observed under different biochar amendments. Bamboo biochar with the rates of 0.5, 1 and 2% reduced cumulative N2O emission by 38%, 48% and 61%, respectively, compare to the control soil in experiment 1. Dolomite and biochar, either alone or combined significantly reduced cumulative N2O emission by 4.6% to 32.7% in experiment 2. Reduction in N2O production under biochar amendment was due to increases in soil pH and decreases in the magnitude of mineral-N in soil. Although, both dolomite and biochar increased cumulative CO2 emission, only biochar amendment had a significant effect. The present study suggests that application of dolomite and biochar to acidic tea field soil can mitigate N2O emissions. PMID:29394272

Effect of dolomite and biochar addition on N2O and CO2 emissions from acidic tea field soil.

PubMed

Oo, Aung Zaw; Sudo, Shigeto; Akiyama, Hiroko; Win, Khin Thuzar; Shibata, Akira; Yamamoto, Akinori; Sano, Tomohito; Hirono, Yuhei

2018-01-01

A laboratory study was conducted to study the effects of liming and different biochar amendments on N2O and CO2 emissions from acidic tea field soil. The first experiment was done with three different rates of N treatment; N 300 (300 kg N ha-1), N 600 (600 kg N ha-1) and N 900 (900 kg N ha-1) and four different rates of bamboo biochar amendment; 0%, 0.5%, 1% and 2% biochar. The second experiment was done with three different biochars at a rate of 2% (rice husk, sawdust, and bamboo) and a control and lime treatment (dolomite) and control at two moisture levels (50% and 90% water filled pore space (WFPS)). The results showed that dolomite and biochar amendment significantly increased soil pH. However, only biochar amendment showed a significant increase in total carbon (C), C/N (the ratio of total carbon and total nitrogen), and C/IN ratio (the ratio of total carbon and inorganic nitrogen) at the end of incubation. Reduction in soil NO3--N concentration was observed under different biochar amendments. Bamboo biochar with the rates of 0.5, 1 and 2% reduced cumulative N2O emission by 38%, 48% and 61%, respectively, compare to the control soil in experiment 1. Dolomite and biochar, either alone or combined significantly reduced cumulative N2O emission by 4.6% to 32.7% in experiment 2. Reduction in N2O production under biochar amendment was due to increases in soil pH and decreases in the magnitude of mineral-N in soil. Although, both dolomite and biochar increased cumulative CO2 emission, only biochar amendment had a significant effect. The present study suggests that application of dolomite and biochar to acidic tea field soil can mitigate N2O emissions.

Responses of Aquatic Bacteria to Terrestrial Runoff: Effects on Community Structure and Key Taxonomic Groups

PubMed Central

Le, Huong T.; Ho, Cuong T.; Trinh, Quan H.; Trinh, Duc A.; Luu, Minh T. N.; Tran, Hai S.; Orange, Didier; Janeau, Jean L.; Merroune, Asmaa; Rochelle-Newall, Emma; Pommier, Thomas

2016-01-01

Organic fertilizer application is often touted as an economical and effective method to increase soil fertility. However, this amendment may increase dissolved organic carbon (DOC) runoff into downstream aquatic ecosystems and may consequently alter aquatic microbial community. We focused on understanding the effects of DOC runoff from soils amended with compost, vermicompost, or biochar on the aquatic microbial community of a tropical reservoir. Runoff collected from a series of rainfall simulations on soils amended with different organic fertilizers was incubated for 16 days in a series of 200 L mesocosms filled with water from a downstream reservoir. We applied 454 high throughput pyrosequencing for bacterial 16S rRNA genes to analyze microbial communities. After 16 days of incubation, the richness and evenness of the microbial communities present decreased in the mesocosms amended with any organic fertilizers, except for the evenness in the mesocosms amended with compost runoff. In contrast, they increased in the reservoir water control and soil-only amended mesocosms. Community structure was mainly affected by pH and DOC concentration. Compared to the autochthonous organic carbon produced during primary production, the addition of allochthonous DOC from these organic amendments seemed to exert a stronger effect on the communities over the period of incubation. While the Proteobacteria and Actinobacteria classes were positively associated with higher DOC concentration, the number of sequences representing key bacterial groups differed between mesocosms particularly between the biochar runoff addition and the compost or vermi-compost runoff additions. The genera of Propionibacterium spp. and Methylobacterium spp. were highly abundant in the compost runoff additions suggesting that they may represent sentinel species of complex organic carbon inputs. Overall, this work further underlines the importance of studying the off-site impacts of organic fertilizers as their impact on downstream aquatic systems is not negligible. PMID:27379034

Responses of Aquatic Bacteria to Terrestrial Runoff: Effects on Community Structure and Key Taxonomic Groups.

PubMed

Le, Huong T; Ho, Cuong T; Trinh, Quan H; Trinh, Duc A; Luu, Minh T N; Tran, Hai S; Orange, Didier; Janeau, Jean L; Merroune, Asmaa; Rochelle-Newall, Emma; Pommier, Thomas

2016-01-01

Organic fertilizer application is often touted as an economical and effective method to increase soil fertility. However, this amendment may increase dissolved organic carbon (DOC) runoff into downstream aquatic ecosystems and may consequently alter aquatic microbial community. We focused on understanding the effects of DOC runoff from soils amended with compost, vermicompost, or biochar on the aquatic microbial community of a tropical reservoir. Runoff collected from a series of rainfall simulations on soils amended with different organic fertilizers was incubated for 16 days in a series of 200 L mesocosms filled with water from a downstream reservoir. We applied 454 high throughput pyrosequencing for bacterial 16S rRNA genes to analyze microbial communities. After 16 days of incubation, the richness and evenness of the microbial communities present decreased in the mesocosms amended with any organic fertilizers, except for the evenness in the mesocosms amended with compost runoff. In contrast, they increased in the reservoir water control and soil-only amended mesocosms. Community structure was mainly affected by pH and DOC concentration. Compared to the autochthonous organic carbon produced during primary production, the addition of allochthonous DOC from these organic amendments seemed to exert a stronger effect on the communities over the period of incubation. While the Proteobacteria and Actinobacteria classes were positively associated with higher DOC concentration, the number of sequences representing key bacterial groups differed between mesocosms particularly between the biochar runoff addition and the compost or vermi-compost runoff additions. The genera of Propionibacterium spp. and Methylobacterium spp. were highly abundant in the compost runoff additions suggesting that they may represent sentinel species of complex organic carbon inputs. Overall, this work further underlines the importance of studying the off-site impacts of organic fertilizers as their impact on downstream aquatic systems is not negligible.

Contributions of pyrogenic materials on the accumulation of soil organic matter

USDA-ARS?s Scientific Manuscript database

Soil amendment of charcoal co-product (HHVdb as high as coal) from thermochemical waste biomass-to-energy conversion (slow/fast pyrolysis and gasification) has received considerable interests for both contaminated and agricultural lands. Biochar amendment not only increases soil organic carbon cont...

Ferric iron amendment increases Fe(III)-reducing microbial diversity and carbon oxidation in on-site wastewater systems.

PubMed

Azam, Hossain M; Finneran, Kevin T

2013-01-01

Onsite wastewater systems, or septic tanks, serve approximately 25% of the United States population; they are therefore a critical component of the total carbon balance for natural water bodies. Septic tanks operate under strictly anaerobic conditions, and fermentation is the dominant process driving carbon transformation. Nitrate, Fe(III), and sulfate reduction may be operating to a limited extent in any given septic tank. Electron acceptor amendments will increase carbon oxidation, but nitrate is toxic and sulfate generates corrosive sulfides, which may damage septic system infrastructure. Fe(III) reducing microorganisms transform all major classes of organic carbon that are dominant in septic wastewater: low molecular weight organic acids, carbohydrate monomers and polymers, and lipids. Fe(III) is not toxic, and the reduction product Fe(II) is minimally disruptive if the starting Fe(III) is added at 50-150 mg L(-1). We used (14)C radiolabeled acetate, lactate, propionate, butyrate, glucose, starch, and oleic acid to demonstrate that short and long-term carbon oxidation is increased when different forms of Fe(III) are amended to septic wastewater. The rates of carbon mineralization to (14)CO(2) increased 2-5 times (relative to unamended systems) in the presence of Fe(III). The extent of mineralization reached 90% for some carbon compounds when Fe(III) was present, compared to levels of 50-60% in the absence of Fe(III). (14)CH(4) was not generated when Fe(III) was added, demonstrating that this strategy can limit methane emissions from septic systems. Amplified 16S rDNA restriction analysis indicated that unique Fe(III)-reducing microbial communities increased significantly in Fe(III)-amended incubations, with Fe(III)-reducers becoming the dominant microbial community in several incubations. The form of Fe(III) added had a significant impact on the rate and extent of mineralization; ferrihydrite and lepidocrocite were favored as solid phase Fe(III) and chelated Fe(III) (with nitrilotriacetic acid or EDTA) as soluble Fe(III) forms. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effect of biochar amendments on microbial transport through soils

USDA-ARS?s Scientific Manuscript database

The incorporation of biochar into soils had been shown to improve soil fertility, enhance soil sequestration of carbon and decrease the mobility of agrochemicals and heavy metals. Our series of column experiments have shown that in addition to these benefits, biochar amendments can limit bacterial t...

Laboratory tests on the impact of superabsorbent polymers on transformation and sorption of xenobiotics in soil taking 14C-imazalil as an example.

PubMed

Achtenhagen, J; Kreuzig, R

2011-11-15

Due to water scarcity, the agricultural production in arid areas is dependent on a sustainable irrigation management. In order to optimize irrigation systems, the application of superabsorbent polymers (SAP) as soil amendments, frequently studied within the last years, may be an appropriate measure to enhance the water holding capacity and the plant-available water in poor arable soils. These persistent polymers are also able to reduce heavy metal and salt stress to crops by accumulating those inorganic compounds. However, the impact of SAP on fate and behavior of organic xenobiotics in soil is unknown. Therefore, transformation and sorption of the model substance 14C-imazalil were monitored without and with SAP amendment in silty sand and sand soil under laboratory conditions. Within the 100-d incubation period, the transformation of 14C-imazalil was not substantially affected by the SAP amendment even though the microbial activity increased considerably. In the silty sand soil, extractable residues dropped from 90% to 45% without and from 96% to 46% with SAP amendment. Non-extractable residues continuously increased up to 49% and 35% while mineralization reached 6% and 5%, respectively. In the sand soil, characterized by its lower microbial activity and lower organic carbon content, extractable residues merely dropped from 99% to 81% and from 100% to 85% while non-extractable residues increased from 2% to 14% and 1% to 10%, respectively. Mineralization was lower than 2%. The increased microbial activity, usually promoting transformation processes of xenobiotics, was compensated by the enhanced sorption in the amended soils revealed by the increase of soil/water distribution coefficients (Kd) of 26 to 42 L kg(-1) for the silty sand and 6 to 25 L kg(-1) for the sand, respectively. Copyright © 2011 Elsevier B.V. All rights reserved.

Integration of behavioral tests and biochemical biomarkers of terrestrial isopod Porcellio scaber (Isopoda, Crustacea) is a promising methodology for testing environmental safety of chars.

PubMed

Madžarić, Suzana; Kos, Monika; Drobne, Damjana; Hočevar, Matej; Jemec Kokalj, Anita

2018-03-01

We investigated how different carbonized materials, or chars (olive mill pomace biochar (BC) and urban greens pruning residues hydrochar (HC)) affect an important member of soil fauna, the terrestrial isopod Porcellio scaber. The selection behavior of isopods towards chars after a 48 h exposure was studied in (i) soil-char amended tests with single and multiple choices, and (ii) tests with chars offered as pure material. Finally, we exposed the isopods to char-amended soils for a period of 14 days to follow the effect on food consumption, body mass and activities of enzymes that are commonly altered upon stressor exposure (acetylcholinesterase, AChE, and glutathione S-transferase, GST). We showed that isopods are able to select between char amended and un-amended soil and different forms of char amendments: a clear preference for BC, and avoidance of HC were evidenced. The preferences remained the same when the chars were sterilized leading to the conclusion that initial microorganism composition was not the reason for selection, but selection was governed by other chars' physico-chemical properties. It remains to be elucidated which of these properties were the dominant reason for the selection. We also showed that isopods intentionally use BC as food at a similar rate to alder leaves. Medium-term exposure to HC resulted in adverse effects on isopods because it led to reduced feeding and growth, in addition to increasing GST activity, although no alterations in AChE activity were found. We suggest that behavioral tests with P. scaber could be used as a fast, reliable and economically feasible screening method for determining the safety of chars for the soil environment. Results represent significant contribution in the field of char toxicity testing, highlighting the importance of tests with isopods as important members of soil meso fauna, with the aim of influencing environmental policies and quality standards. Copyright © 2017 Elsevier Ltd. All rights reserved.

Native Soil Charcoal as a Model for Designing Biochar for Carbon Sequestration

EPA Science Inventory

Under changing climate a variety of mechanisms for removing carbon from the atmosphere and sequestering it elsewhere are being considered to reduce the forcing of the atmosphere. Amending soils with biochar has been proposed as one long-term means of sequestering carbon originat...

Two decades of warming increases diversity of a potentially lignolytic bacterial community

PubMed Central

Pold, Grace; Melillo, Jerry M.; DeAngelis, Kristen M.

2015-01-01

As Earth's climate warms, the massive stores of carbon found in soil are predicted to become depleted, and leave behind a smaller carbon pool that is less accessible to microbes. At a long-term forest soil-warming experiment in central Massachusetts, soil respiration and bacterial diversity have increased, while fungal biomass and microbially-accessible soil carbon have decreased. Here, we evaluate how warming has affected the microbial community's capability to degrade chemically-complex soil carbon using lignin-amended BioSep beads. We profiled the bacterial and fungal communities using PCR-based methods and completed extracellular enzyme assays as a proxy for potential community function. We found that lignin-amended beads selected for a distinct community containing bacterial taxa closely related to known lignin degraders, as well as members of many genera not previously noted as capable of degrading lignin. Warming tended to drive bacterial community structure more strongly in the lignin beads, while the effect on the fungal community was limited to unamended beads. Of those bacterial operational taxonomic units (OTUs) enriched by the warming treatment, many were enriched uniquely on lignin-amended beads. These taxa may be contributing to enhanced soil respiration under warming despite reduced readily available C availability. In aggregate, these results suggest that there is genetic potential for chemically complex soil carbon degradation that may lead to extended elevated soil respiration with long-term warming. PMID:26042112

Positioning activated carbon amendment technologies in a novel framework for sediment management.

PubMed

Kupryianchyk, Darya; Rakowska, Magdalena I; Reible, Danny; Harmsen, Joop; Cornelissen, Gerard; van Veggel, Marc; Hale, Sarah E; Grotenhuis, Tim; Koelmans, Albert A

2015-04-01

Contaminated sediments can pose serious threats to human health and the environment by acting as a source of toxic chemicals. The amendment of contaminated sediments with strong sorbents like activated C (AC) is a rapidly developing strategy to manage contaminated sediments. To date, a great deal of attention has been paid to the technical and ecological features and implications of sediment remediation with AC, although science in this field still is rapidly evolving. This article aims to provide an update on the recent literature on these features, and provides a comparison of sediment remediation with AC to other sediment management options, emphasizing their full-scale application. First, a qualitative overview of advantages of current alternatives to remediate contaminated sediments is presented. Subsequently, AC treatment technology is critically reviewed, including current understanding of the effectiveness and ecological safety for the use of AC in natural systems. Finally, this information is used to provide a novel framework for supporting decisions concerning sediment remediation and beneficial reuse. © 2015 SETAC.

Microbial response to triepthylphosphate

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

Hazen, T.C.; Santo Domingo, J.W.; Berry, C.J.

1997-05-01

The effect of triethylphosphate (TEP) on the activity of a landfill aquifer microbial community was evaluated using standard techniques and in situ hybridizations with phylogenetic probes. Benzene was used as an external carbon source to monitor degradation of an aromatic compound in TEP amended microcosms. Microscopical and viable counts were higher in TEP containing microcosms when compared to unamended controls. A significant increase in metabolic activity was also observed for TEP amended samples as determined by the number of cells hybridizing to an eubacterial probe. In addition, the number of beta and gamma Proteobacteria increased from undetectable levels prior tomore » the study to 15-29% of the total bacteria in microcosms containing TEP and benzene. In these microcosms, nearly 40% of the benzene was degraded during the incubation period compared to less than 5% in unamended microcosms. While TEP has previously been used as an alternate phosphate source in the bioremediation of chlorinated aliphatics, this study shows that it can also stimulate the microbial degradation of aromatics in phosphate limited aquifers.« less

Effects of mussel shell addition on the chemical and biological properties of a Cambisol.

PubMed

Paz-Ferreiro, J; Baez-Bernal, D; Castro Insúa, J; García Pomar, M I

2012-03-01

The use of a by-product of the fisheries industry (mussel shell) combined with cattle slurry was evaluated as soil amendment, with special attention to the biological component of soil. A wide number of properties related to soil quality were measured: microbial biomass, soil respiration, net N mineralization, dissolved organic carbon, dissolved organic nitrogen, dissolved inorganic nitrogen, dehydrogenase, β-glucosidase, urease and phosphomonoesterase activities. The amendments showed an enhancement of soil biological activity and a decrease of aluminium held in the cation exchange complex. No adverse effects were observed on soil properties. Given that mussel shells are produced in coastal areas as a by-product and have to be managed as a waste and the fertility constraints in the local soils due to their low pH, our research suggest that there is an opportunity for disposing a residue into the soil and improving soil fertility. Copyright © 2011 Elsevier Ltd. All rights reserved.

Blending foundry sands with soil: Effect on dehydrogenase activity.

PubMed

Dungan, Robert S; Kukier, Urzsula; Lee, Brad

2006-03-15

Each year U.S. foundries landfill several million tons of sand that can no longer be used to make metalcasting molds and cores. A possible use for these materials is as an ingredient in manufactured soils; however, potentially harmful metals and resin binders (used to make cores) may adversely impact the soil microbial community. In this study, the dehydrogenase activity (DHA) of soil amended with molding sand (clay-coated sand known as "green sand") or core sands at 10%, 30%, and 50% (dry wt.) was determined. The green sands were obtained from iron, aluminum, and brass foundries; the core sands were made with phenol-formaldehyde or furfuryl alcohol based resins. Overall, incremental additions of these sands resulted in a decrease in the DHA which lasted throughout the 12-week experimental period. A brass green sand, which contained high concentrations of Cu, Pb, and Zn, severely impacted the DHA. By week 12 no DHA was detected in the 30% and 50% treatments. In contrast, the DHA in soil amended with an aluminum green sand was 2.1 times higher (all blending ratios), on average, at week 4 and 1.4 times greater (30% and 50% treatments only) than the controls by week 12. In core sand-amended soil, the DHA results were similar to soils amended with aluminum and iron green sands. Increased activity in some treatments may be a result of the soil microorganisms utilizing the core resins as a carbon source. The DHA assay is a sensitive indicator of environmental stress caused by foundry sand constituents and may be useful to assess which foundry sands are suitable for beneficial use in the environment.

Addition of biochar to simulated golf greens promotes creeping bentgrass growth

USDA-ARS?s Scientific Manuscript database

Organic amendments such as peat moss and various composts are typically added to sand-based root zones such as golf greens to increase water and nutrient retention. However, these attributes are generally lost as these amendments decompose in a few years. Biochar is a high carbon, extremely porous ...

Stabilization of lead and copper by biochar amendments in arms range soils: Influence of biochar characteristics, soil property, and equilibrium conditions

USDA-ARS?s Scientific Manuscript database

Soil amendment of char products (biochar) from thermochemical processing (slow/fast pyrolysis and gasification) of biomass for biofuel production has received considerable interests for contaminant sorption, soil fertilization, and carbon sequestration. Of potential sites for biochar application, h...

Biosolids amendment dramatically increases sequestration of crop residue-carbon in agricultural soils in western Illinois

USDA-ARS?s Scientific Manuscript database

Release of carbon dioxide through microbial respiration from the world’s crop residues (non-edible plant parts left in the field after harvest) represents an important form of carbon transfer from terrestrial ecosystems to the atmosphere. We hypothesized that alleviation of environmental stress (moi...

Pyrochars and hydrochars differently alter the sorption of the herbicide isoproturon in an agricultural soil.

PubMed

Eibisch, Nina; Schroll, Reiner; Fuß, Roland; Mikutta, Robert; Helfrich, Mirjam; Flessa, Heinz

2015-01-01

Carbonaceous material from pyrolysis (pyrochars) and hydrothermal carbonization (hydrochars) are applied to soil to improve soil fertility and carbon sequestration. As a positive side effect, the mobility of pesticides and the risk of groundwater contamination can be minimized. However, the impact of various raw materials on the sorption capacity of different pyrochars and hydrochars is poorly understood. Thus, sorption experiments were performed with (14)C-labeled isoproturon (IPU, 0.75 kg ha(-1)) in a loamy sand soil amended with either pyrochar or hydrochar (0.5% and 5% dry weight, respectively). Carbonaceous materials were produced from three different raw materials: corn digestate, miscanthus, woodchips of willow and poplar. After 72 h of incubation, a sequential extraction procedure was conducted to quantify in situ IPU bioavailability, total amount of extractable IPU, and non-extractable pesticide residues (NER). Added char amount, carbonization type, and raw materials had statistically significant effects on the sorption of IPU. The amount of in situ available IPU was reduced by a factor of 10-2283 in treatments with pyrochar and by a factor of 3-13 in hydrochar treatments. The surface area of the charred material was the most predictive variable of IPU sorption to char amended soil. Some physical and chemical char properties tend to correlate with pore water-, methanol- or non-extractable IPU amounts. Due to a low micro-porosity and ash content, high water extractable carbon contents and O-functional groups of hydrochars, the proportion of NER in hydrochar amended soils was considerably lower than in soil amended with pyrochars. Copyright © 2014 Elsevier Ltd. All rights reserved.

Cross Validation of Two Partitioning-Based Sampling Approaches in Mesocosms Containing PCB Contaminated Field Sediment, Biota, and Activated Carbon Amendment.

PubMed

Schmidt, Stine N; Wang, Alice P; Gidley, Philip T; Wooley, Allyson H; Lotufo, Guilherme R; Burgess, Robert M; Ghosh, Upal; Fernandez, Loretta A; Mayer, Philipp

2017-09-05

The Gold Standard for determining freely dissolved concentrations (C free ) of hydrophobic organic compounds in sediment interstitial water would be in situ deployment combined with equilibrium sampling, which is generally difficult to achieve. In the present study, ex situ equilibrium sampling with multiple thicknesses of silicone and in situ pre-equilibrium sampling with low density polyethylene (LDPE) loaded with performance reference compounds were applied independently to measure polychlorinated biphenyls (PCBs) in mesocosms with (1) New Bedford Harbor sediment (MA, U.S.A.), (2) sediment and biota, and (3) activated carbon amended sediment and biota. The aim was to cross validate the two different sampling approaches. Around 100 PCB congeners were quantified in the two sampling polymers, and the results confirmed the good precision of both methods and were in overall good agreement with recently published LDPE to silicone partition ratios. Further, the methods yielded C free in good agreement for all three experiments. The average ratio between C free determined by the two methods was factor 1.4 ± 0.3 (range: 0.6-2.0), and the results thus cross-validated the two sampling approaches. For future investigations, specific aims and requirements in terms of application, data treatment, and data quality requirements should dictate the selection of the most appropriate partitioning-based sampling approach.

Biochar Improves Soil Aggregate Stability and Water Availability in a Mollisol after Three Years of Field Application

PubMed Central

Zhang, Yulan; Yang, Lijie; Yu, Chunxiao; Yin, Guanghua; Doane, Timothy A.; Wu, Zhijie; Zhu, Ping; Ma, Xingzhu

2016-01-01

A field experiment was carried out to evaluate the effect of organic amendments on soil organic carbon, total nitrogen, bulk density, aggregate stability, field capacity and plant available water in a representative Chinese Mollisol. Four treatments were as follows: no fertilization (CK), application of inorganic fertilizer (NPK), combined application of inorganic fertilizer with maize straw (NPK+S) and addition of biochar with inorganic fertilizer (NPK+B). Our results showed that after three consecutive years of application, the values of soil bulk density were significantly lower in both organic amendment-treated plots than in unamended (CK and NPK) plots. Compared with NPK, NPK+B more effectively increased the contents of soil organic carbon, improved the relative proportion of soil macro-aggregates and mean weight diameter, and enhanced field capacity as well as plant available water. Organic amendments had no obvious effect on soil C/N ratio or wilting coefficient. The results of linear regression indicated that the improvement in soil water retention could be attributed to the increases in soil organic carbon and aggregate stability. PMID:27191160

Biochar Improves Soil Aggregate Stability and Water Availability in a Mollisol after Three Years of Field Application.

PubMed

Ma, Ningning; Zhang, Lili; Zhang, Yulan; Yang, Lijie; Yu, Chunxiao; Yin, Guanghua; Doane, Timothy A; Wu, Zhijie; Zhu, Ping; Ma, Xingzhu

2016-01-01

A field experiment was carried out to evaluate the effect of organic amendments on soil organic carbon, total nitrogen, bulk density, aggregate stability, field capacity and plant available water in a representative Chinese Mollisol. Four treatments were as follows: no fertilization (CK), application of inorganic fertilizer (NPK), combined application of inorganic fertilizer with maize straw (NPK+S) and addition of biochar with inorganic fertilizer (NPK+B). Our results showed that after three consecutive years of application, the values of soil bulk density were significantly lower in both organic amendment-treated plots than in unamended (CK and NPK) plots. Compared with NPK, NPK+B more effectively increased the contents of soil organic carbon, improved the relative proportion of soil macro-aggregates and mean weight diameter, and enhanced field capacity as well as plant available water. Organic amendments had no obvious effect on soil C/N ratio or wilting coefficient. The results of linear regression indicated that the improvement in soil water retention could be attributed to the increases in soil organic carbon and aggregate stability.

Influence of organic amendments on nickel phytoextraction and growth effects to Trifolium alexandrinum

NASA Astrophysics Data System (ADS)

Shahid, Muhammad; Sabir, Muhammad; Ghafoor, Abdul

2013-04-01

Heavy metal pollution of soil and other environmental compartments through anthropogenic activities and/or natural processes is a widespread and serious problem confronting society, scientists, and regulators worldwide (Shahid et al., 2011). Among the heavy metals, Ni is an essential heavy metal and plays many functions in living organisms (Khoshgoftarmanesh et al., 2011). The presence of this metal in soil or growth medium may have positive biological effects on plant growth. However, Ni may interfere with various morphological, physiological and biochemical process in plants when its concentration rises to supra-optimal values i.e., 100 mg kg-1 in plants and 420 kg ha-I in soil (Tucker, 2005). The use of organic amendments is a common practice in Pakistan to improve soil fertility. Organic amendments are known to affect chemical speciation and bioavailability of heavy metals and in turn their uptake and toxicity to plants (Shahid et al., 2012). The present study evaluate the influence of organic amendments viz. farm yard manure (FM), poultry manure (PM), press mud (PrM) and activated carbon (AC) on Ni bioavailability in soil as well as its uptake and growth responses of Trifolium alexandrinum. A pot experiment was conducted where T. alexandrinum was exposed to three different Ni level i.e., 30, 60 and 90 mg kg-1 in the form of NiCl2 solution in the presence and absence of organic amendments each applied at 15 g kg-1 soil. The results showed that the effect of organic amendments on Ni bioavailability and uptake by T. alexandrinum depend on Ni levels in soil and amendment type. Application of organic amendments generally increased Ni phytoavailability in soil and Ni uptake by plants at low Ni levels (Ni-0 and Ni-30) but decreased at higher levels (Ni-60 and Ni-90). It is proposed that the soil Ni levels and amendment type must be considered while using these amendments in Ni remediation and risk assessment studies. Keywords: Nickel, organic amendments, bioavailability, Trifolium alexandrinum, plant growth. REFERENCES Shahid M, Pinelli E, Dumat C, 2012. Review of Pb availability and toxicity to plants in relation with metal speciation; role of synthetic and natural organic ligands. Journal of Hazardous Materials, 219-220: 1-12. Shahid M, Pinelli E, Pourrut B, Silvestre J, Dumat C, 2011. Lead-induced genotoxicity to Vicia faba L. roots in relation with metal cell uptake and initial speciation. Ecotoxicology and Environmental Safety, 74(1): 78-84. Khoshgoftarmanesh, A.H. Hosseini, F. and Afyuni, M. (2011) Nickel supplementation effect on the growth, urease activity and urea and nitrate concentrations in lettuce supplied with different nitrogen sources. Sci. Horti., 130, 381-385. Tucker, M.R. Hardy, D.H. and Stokes, C.E. (2005) Heavy metals in North Carolina soils: occurrence and significance. North Carolina Department of Agriculture and Consumer Services, Agronomic Division.

Assessment of degradation potential of aliphatic hydrocarbons by autochthonous filamentous fungi from a historically polluted clay soil.

PubMed

Covino, Stefano; D'Annibale, Alessandro; Stazi, Silvia Rita; Cajthaml, Tomas; Čvančarová, Monika; Stella, Tatiana; Petruccioli, Maurizio

2015-02-01

The present work was aimed at isolating and identifying the main members of the mycobiota of a clay soil historically contaminated by mid- and long-chain aliphatic hydrocarbons (AH) and to subsequently assess their hydrocarbon-degrading ability. All the isolates were Ascomycetes and, among them, the most interesting was Pseudoallescheria sp. 18A, which displayed both the ability to use AH as the sole carbon source and to profusely colonize a wheat straw:poplar wood chip (70:30, w/w) lignocellulosic mixture (LM) selected as the amendment for subsequent soil remediation microcosms. After a 60 d mycoaugmentation with Pseudoallescheria sp. of the aforementioned soil, mixed with the sterile LM (5:1 mass ratio), a 79.7% AH reduction and a significant detoxification, inferred by a drop in mortality of Folsomia candida from 90 to 24%, were observed. However, similar degradation and detoxification outcomes were found in the non-inoculated incubation control soil that had been amended with the sterile LM. This was due to the biostimulation exerted by the amendment on the resident microbiota, fungi in particular, the activity and density of which were low, instead, in the non-amended incubation control soil. Copyright © 2014 Elsevier B.V. All rights reserved.

Quality of fresh organic matter affects priming of soil organic matter and substrate utilization patterns of microbes

PubMed Central

Wang, Hui; Boutton, Thomas W.; Xu, Wenhua; Hu, Guoqing; Jiang, Ping; Bai, Edith

2015-01-01

Changes in biogeochemical cycles and the climate system due to human activities are expected to change the quantity and quality of plant litter inputs to soils. How changing quality of fresh organic matter (FOM) might influence the priming effect (PE) on soil organic matter (SOM) mineralization is still under debate. Here we determined the PE induced by two 13C-labeled FOMs with contrasting nutritional quality (leaf vs. stalk of Zea mays L.). Soils from two different forest types yielded consistent results: soils amended with leaf tissue switched faster from negative PE to positive PE due to greater microbial growth compared to soils amended with stalks. However, after 16 d of incubation, soils amended with stalks had a higher PE than those amended with leaf. Phospholipid fatty acid (PLFA) results suggested that microbial demand for carbon and other nutrients was one of the major determinants of the PE observed. Therefore, consideration of both microbial demands for nutrients and FOM supply simultaneously is essential to understand the underlying mechanisms of PE. Our study provided evidence that changes in FOM quality could affect microbial utilization of substrate and PE on SOM mineralization, which may exacerbate global warming problems under future climate change. PMID:25960162

Measurement and modeling of polychlorinated biphenyl bioaccumulation from sediment for the marine polychaete neanthes arenaceodentata and response to sorbent amendment

USGS Publications Warehouse

Janssen, E.M.-L.; Croteau, M.-N.; Luoma, S.N.; Luthy, R.G.

2010-01-01

Bioaccumulation rates of polychlorinated biphenyls (PCBs) for the marine polychaete Neanthes arenaceodentata were characterized, including PCB uptake rates from water and sediment, and the effect of sorbent amendment to the sediment on PCB bioavailability, organism growth, and lipid content. Physiological parameters were incorporated into a biodynamic model to predict contaminant uptake. The results indicate rapid PCB uptake from contaminated sediment and significant organism growth dilution during time-series exposure studies. PCB uptake from the aqueous phase accounted for less than 3% of the total uptake for this deposit-feeder. Proportional increase of gut residence time and assimilation efficiency as a consequence of the organism's growth was assessed by PCB uptake and a reactor theory model of gut architecture. Pulse-chase feeding and multilabeled stable isotope tracing techniques proved high sediment ingestion rates (i.e., 6?10 times of dry body weight per day) indicating that such deposit-feeders are promising biological indicators for sediment risk assessment. Activated carbon amendment reduced PCB uptake by 95% in laboratory experiments with no observed adverse growth effects on the marine polychaete. Biodynamic modeling explained the observed PCB body burdens for N. arenaceodentata, with and without sorbent amendment. ?? 2009 American Chemical Society.

Quality of fresh organic matter affects priming of soil organic matter and substrate utilization patterns of microbes.

PubMed

Wang, Hui; Boutton, Thomas W; Xu, Wenhua; Hu, Guoqing; Jiang, Ping; Bai, Edith

2015-05-11

Changes in biogeochemical cycles and the climate system due to human activities are expected to change the quantity and quality of plant litter inputs to soils. How changing quality of fresh organic matter (FOM) might influence the priming effect (PE) on soil organic matter (SOM) mineralization is still under debate. Here we determined the PE induced by two (13)C-labeled FOMs with contrasting nutritional quality (leaf vs. stalk of Zea mays L.). Soils from two different forest types yielded consistent results: soils amended with leaf tissue switched faster from negative PE to positive PE due to greater microbial growth compared to soils amended with stalks. However, after 16 d of incubation, soils amended with stalks had a higher PE than those amended with leaf. Phospholipid fatty acid (PLFA) results suggested that microbial demand for carbon and other nutrients was one of the major determinants of the PE observed. Therefore, consideration of both microbial demands for nutrients and FOM supply simultaneously is essential to understand the underlying mechanisms of PE. Our study provided evidence that changes in FOM quality could affect microbial utilization of substrate and PE on SOM mineralization, which may exacerbate global warming problems under future climate change.

Quality of fresh organic matter affects priming of soil organic matter and substrate utilization patterns of microbes

NASA Astrophysics Data System (ADS)

Wang, Hui; Boutton, Thomas W.; Xu, Wenhua; Hu, Guoqing; Jiang, Ping; Bai, Edith

2015-05-01

Changes in biogeochemical cycles and the climate system due to human activities are expected to change the quantity and quality of plant litter inputs to soils. How changing quality of fresh organic matter (FOM) might influence the priming effect (PE) on soil organic matter (SOM) mineralization is still under debate. Here we determined the PE induced by two 13C-labeled FOMs with contrasting nutritional quality (leaf vs. stalk of Zea mays L.). Soils from two different forest types yielded consistent results: soils amended with leaf tissue switched faster from negative PE to positive PE due to greater microbial growth compared to soils amended with stalks. However, after 16 d of incubation, soils amended with stalks had a higher PE than those amended with leaf. Phospholipid fatty acid (PLFA) results suggested that microbial demand for carbon and other nutrients was one of the major determinants of the PE observed. Therefore, consideration of both microbial demands for nutrients and FOM supply simultaneously is essential to understand the underlying mechanisms of PE. Our study provided evidence that changes in FOM quality could affect microbial utilization of substrate and PE on SOM mineralization, which may exacerbate global warming problems under future climate change.

Biochar amendment decreases soil microbial biomass and increases bacterial diversity in Moso bamboo (Phyllostachys edulis) plantations under simulated nitrogen deposition

NASA Astrophysics Data System (ADS)

Li, Quan; Lei, Zhaofeng; Song, Xinzhang; Zhang, Zhiting; Ying, Yeqing; Peng, Changhui

2018-04-01

Biochar amendment has been proposed as a strategy to improve acidic soils after overuse of nitrogen fertilizers. However, little is known of the role of biochar in soil microbial biomass carbon (MBC) and bacterial community structure and diversity after soil acidification induced by nitrogen (N) deposition. Using high-throughput sequencing of the 16S rRNA gene, we determined the effects of biochar amendment (BC0, 0 t bamboo biochar ha‑1 BC20, 20 t bamboo biochar ha‑1 and BC40, 40 t bamboo biochar ha‑1) on the soil bacterial community structure and diversity in Moso bamboo plantations that had received simulated N deposition (N30, 30 kg N ha‑1 yr‑1 N60, 60 kg N ha‑1 yr‑1 N90, 90 kg N ha‑1 yr‑1 and N-free) for 21 months. After treatment of N-free plots, BC20 significantly increased soil MBC and bacterial diversity, while BC40 significantly decreased soil MBC but increased bacterial diversity. When used to amend N30 and N60 plots, biochar significantly decreased soil MBC and the reducing effect increased with biochar amendment amount. However, these significant effects were not observed in N90 plots. Under N deposition, biochar amendment largely increased soil bacterial diversity, and these effects depended on the rates of N deposition and biochar amendment. Soil bacterial diversity was significantly related to the soil C/N ratio, pH, and soil organic carbon content. These findings suggest an optimal approach for using biochar to offset the effects of N deposition in plantation soils and provide a new perspective for understanding the potential role of biochar amendments in plantation soil.

Amending the Structure of Renewable Carbon from Biorefinery Waste-Streams for Energy Storage Applications.

PubMed

Ho, Hoi Chun; Goswami, Monojoy; Chen, Jihua; Keum, Jong K; Naskar, Amit K

2018-05-29

Biorefineries produce impure sugar waste streams that are being underutilized. By converting this waste to a profitable by-product, biorefineries could be safeguarded against low oil prices. We demonstrate controlled production of useful carbon materials from the waste concentrate via hydrothermal synthesis and carbonization. We devise a pathway to producing tunable, porous spherical carbon materials by modeling the gross structure formation and developing an understanding of the pore formation mechanism utilizing simple reaction principles. Compared to a simple hydrothermal synthesis from sugar concentrate, emulsion-based synthesis results in hollow spheres with abundant microporosity. In contrast, conventional hydrothermal synthesis produces solid beads with micro and mesoporosity. All the carbonaceous materials show promise in energy storage application. Using our reaction pathway, perfect hollow activated carbon spheres can be produced from waste sugar in liquid effluence of biomass steam pretreatment units. The renewable carbon product demonstrated a desirable surface area of 872 m 2 /g and capacitance of up to 109 F/g when made into an electric double layer supercapacitor. The capacitor exhibited nearly ideal capacitive behavior with 90.5% capacitance retention after 5000 cycles.

Fluctuations in Species-Level Protein Expression Occur during Element and Nutrient Cycling in the Subsurface

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

Wilkins, Michael J.; Wrighton, Kelly C.; Nicora, Carrie D.

2013-03-05

While microbial activities in environmental systems play a key role in the utilization and cycling of essential elements and compounds, microbial activity and growth frequently fluctuates in response to environmental stimuli and perturbations. To investigate these fluctuations within a saturated aquifer system, we monitored a carbon-stimulated in situ Geobacter population while iron reduction was occurring, using 16S rRNA abundances and high-resolution tandem mass spectrometry proteome measurements. Following carbon amendment, 16S rRNA analysis of temporally separated samples revealed the rapid enrichment of Geobacter-like environmental strains with strong similarity to G. bemidjiensis. Tandem mass spectrometry proteomics measurements suggest high carbon flux throughmore » Geobacter respiratory pathways, and the synthesis of anapleurotic four carbon compounds from acetyl-CoA via pyruvate ferredoxin oxidoreductase activity. Across a 40-day period where Fe(III) reduction was occurring, fluctuations in protein expression reflected changes in anabolic versus catabolic reactions, with increased levels of biosynthesis occurring soon after acetate arrival in the aquifer. In addition, localized shifts in nutrient limitation were inferred based on expression of nitrogenase enzymes and phosphate uptake proteins. These temporal data offer the first example of differing microbial protein expression associated with changing geochemical conditions in a subsurface environment.« less

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

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.

Mid-term effects of mine soil reclamation by use of aided phytostabilization

NASA Astrophysics Data System (ADS)

Zornoza, Raúl; Faz, Ángel; Martínez-Martínez, Silvia; Acosta, Jose Alberto; Gómez, María Dolores; Yanardag, Ibrahim

2014-05-01

Abandoned tailing ponds show environmental and human health hazards by the transfer of heavy metals through erosion or leaching. To reduce these hazards, a reclamation strategy has been developed on a tailing pond based on aided phytostabilization. In 2011 marble mud and pig slurry were applied on the tailing pond surface. In spring 2012 thirteen native vegetal species were introduced. During two years (2012-2013) the evolution of different soil properties and the bioavailable fraction of the heavy metals Cd, Pb and Zn has been monitored. Results showed that pH, aggregates stability, organic carbon, nitrogen and cation exchange capacity increased with the application of the amendments and the development of vegetation, while the bioavailable fraction of the heavy metals drastically decreased (90-99%). Thus, the strategy followed resulted positive to reduce the availability of heavy metals, improving soil quality and fertility. These results are promising in areas with extractive activity of carbonated materials, since the generated wastes can be used for reclamation of soils affected with heavy metals, turning a waste into a by-product. Key words: amendments, geochemistry, heavy metals, mining, tailing pond. Acknowledgements: This work has been funded by the European Union LIFE+ project MIPOLARE (LIFE09 ENV/ES/000439).

Trajectories of Microbial Community Function in Response to Accelerated Remediation of Subsurface Metal Contaminants

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

Firestone, Mary

Objectives of proposed research were to; Determine if the trajectories of microbial community composition and function following organic carbon amendment can be related to, and predicted by, key environmental determinants; Assess the relative importance of the characteristics of the indigenous microbial community, sediment, groundwater, and concentration of organic carbon amendment as the major determinants of microbial community functional response and bioremediation capacity; and Provide a fundamental understanding of the microbial community ecology underlying subsurface metal remediation requisite to successful application of accelerated remediation and long-term stewardship of DOE-IFC sites.

48 CFR 225.7011-3 - Contract clause.

Code of Federal Regulations, 2010 CFR

2010-10-01

... granted, use the clause at 252.225-7030, Restriction on Acquisition of Carbon, Alloy, and Armor Steel Plate, in solicitations and contracts that' (a) Require the delivery to the Government of carbon, alloy... control of DoD to purchase carbon, alloy, or armor steel plate. [68 FR 15627, Mar. 31, 2003, as amended at...

48 CFR 225.7011-3 - Contract clause.

Code of Federal Regulations, 2011 CFR

2011-10-01

... granted, use the clause at 252.225-7030, Restriction on Acquisition of Carbon, Alloy, and Armor Steel Plate, in solicitations and contracts that' (a) Require the delivery to the Government of carbon, alloy... control of DoD to purchase carbon, alloy, or armor steel plate. [68 FR 15627, Mar. 31, 2003, as amended at...

75 FR 80455 - Certain Hot-Rolled Carbon Steel Flat Products From India: Amended Final Results of Countervailing...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-22

... DEPARTMENT OF COMMERCE International Trade Administration [C-533-821] Certain Hot-Rolled Carbon...-rolled carbon steel flat products (HRCS) from India covering the 2006 POR, to reflect the CIT's order in... INFORMATION: Background On July 14, 2008, the Department published its final results in the countervailing...

Stimulation of methanogenesis in anaerobic digesters treating leachate from a municipal solid waste incineration plant with carbon cloth.

PubMed

Lei, Yuqing; Sun, Dezhi; Dang, Yan; Chen, Huimin; Zhao, Zhiqiang; Zhang, Yaobin; Holmes, Dawn E

2016-12-01

Bio-methanogenic digestion of incineration leachate is hindered by high OLRs, which can lead to build-up of VFAs, drops in pH and ultimately in reactor souring. It was hypothesized that incorporation of carbon cloth into reactors treating leachate would promote DIET and enhance reactor performance. To examine this possibility, carbon cloth was added to laboratory-scale UASB reactors that were fed incineration leachate. As expected, the carbon-cloth amended reactor could operate stably with a 34.2% higher OLR than the control (49.4 vs 36.8kgCOD/(m 3 d)). Microbial community analysis showed that bacteria capable of extracellular electron transfer and methanogens known to participate in DIET were enriched on the carbon cloth surface, and conductivity of sludge from the carbon cloth amended reactor was almost twofold higher than sludge from the control (9.77 vs 5.47μS/cm), suggesting that microorganisms in the experimental reactor may have been expressing electrically conductive filaments. Copyright © 2016 Elsevier Ltd. All rights reserved.

Carbon dioxide emissions from agricultural soils amended with livestock-derived organic materials

NASA Astrophysics Data System (ADS)

Pezzolla, D.; Said-Pullicino, D.; Gigliotti, G.

2009-04-01

Carbon dioxide gas xchange between terrestrial ecosystems and the atmosphere, as well as the carbon sink strength of various arable land ecosystems, is of primary interest for global change research. Measures for increasing soil C inputs include the preferential use of livestock-derived organic materials (e.g. animal manure and slurries, digestate from biogas production plants and compost). The application of such materials to agricultural soils returns essential nutrients for plant growth and organic matter to maintain long-term fertility. Whether or not such practices ultimately result in sustained C sequestration at the ecosystem level will depend on their mineralization rates. This work presents preliminary results from a laboratory incubation trial to evaluate carbon dioxide fluxes from two agricultural soils (a calcareous silt loam and a silty clay loam) amended with agricultural doses of (i) pig slurry (PSL), (ii) the digestate from the anaerobic fermentation of pig slurries (AAS) and (ii) a compost from the aerobic stabilisation of the digestate (LDC). These subsequent steps of slurry stabilisation resulted in a decrease in the content of labile organic matter which was reflected in a reduction in maximum carbon dioxide emission rates from amended soils. Measurements have shown that peak emissions from soils occur immediately after application of these organic materials (within 5 days) and decrease in the order PSL > AAS > LDC. Moreover, mean cumulative emissions over the first 40 days showed that a higher percentage (about 44%) of the C added with PSL was mineralised respect to C added with AAS (39%) and LDC (25%). Although it was hypothesised that apart from the quantity and stability of the added organic materials, even soil characteristics could influence C mineralisation rates, no significant differences were observed between emission fluxes for similarly treated soils. Mean cumulative emission fluxes after 40 days from treatment were of 114, 103 and 84 g C m-2 for PSL, AAS and LDC respectively. Carbon dioxide emission rates were corroborated with results obtained from the quantification of water-extractable organic C (WEOC) and soil microbial biomass-C (Cmic). The former represents the more labile fraction of soil organic matter and its concentration in the freshly amended soils followed the order LDC > AAS ≈ PSL. However, whereas WEOC concentrations decrease rapidly for PSL and LDC amended soils, AAS treated soils showed a steady increase during the first 20 days of incubation followed by a decrease thereafter. This was attributed to the release of soluble organic matter from the anaerobically stabilised digestate in the presence of an aerobic soil microbial community. Irrespective of the type of amendment, Cmic values increased with time with respect to the unamended controls, reaching highest values after 20 days from amendment and decreasing thereafter. Even after 40 days of incubation, Cmic values in all amended soils did not return to the background values obtained with unamended controls. These results suggest that the application of stabilised livestock-derived organic materials to soils may play an important role in reducing C emissions associated with agricultural practices and increase soil C stocks, apart from other indirect beneficial effects such as the recovery of energy from combustion of biogas from anaerobic fermentation of these waste materials.

Effects of particulate carbonaceous matter on the bioavailability of benzo[a]pyrene and 2,2‘,5,5‘-tetrachlorobiphenyl to the clam, Macoma balthica

USGS Publications Warehouse

McLeod, Pamela B.; van den Heuvel-Greve, Martine J.; Allen-King, Richelle M.; Luoma, Samuel N.; Luthy, Richard G.

2004-01-01

We investigated the bioavailability via diet of spiked benzo[a]pyrene (BaP) and 2,2‘,5,5‘-tetrachlorobiphenyl (PCB-52) from different carbonaceous (non-carbonate, carbon containing) particle types to clams (Macoma balthica) collected from San Francisco Bay. Our results reveal significant differences in absorption efficiency between compounds and among carbonaceous particle types. Absorption efficiency for PCB-52 was always greater than that for BaP bound to a given particle type. Among particles, absorption efficiency was highest from wood and diatoms and lowest from activated carbon. Large differences in absorption efficiency could not be simply explained by comparatively small differences in the particles' total organic carbon content. BaP and PCB-52 bound to activated carbon exhibited less than 2% absorption efficiency and were up to 60 times less available to clams than the same contaminants associated with other types of carbonaceous matter. These results suggest that variations in the amount and type of sediment particulate carbonaceous matter, whether naturally occurring or added as an amendment, will have a strong influence on the bioavailability of hydrophobic organic contaminants. This has important implications for environmental risk assessment, sediment management, and development of novel remediation techniques.

Effects of particulate carbonaceous matter on the bioavailability of benzo[a]pyrene and 2,2'5,5'-tetrachlorobiphenyl to the clam, Macoma balthica

USGS Publications Warehouse

McLeod, Pamela B.; van den Heuvel-Greve, Martine J.; Allen-King, Richelle M.; Luoma, Samuel N.; Luthy, Richard G.

2004-01-01

We investigated the bioavailability via diet of spiked benzo[a]pyrene (BaP) and 2,2‘,5,5‘-tetrachlorobiphenyl (PCB-52) from different carbonaceous (non-carbonate, carbon containing) particle types to clams (Macoma balthica) collected from San Francisco Bay. Our results reveal significant differences in absorption efficiency between compounds and among carbonaceous particle types. Absorption efficiency for PCB-52 was always greater than that for BaP bound to a given particle type. Among particles, absorption efficiency was highest from wood and diatoms and lowest from activated carbon. Large differences in absorption efficiency could not be simply explained by comparatively small differences in the particles' total organic carbon content. BaP and PCB-52 bound to activated carbon exhibited less than 2% absorption efficiency and were up to 60 times less available to clams than the same contaminants associated with other types of carbonaceous matter. These results suggest that variations in the amount and type of sediment particulate carbonaceous matter, whether naturally occurring or added as an amendment, will have a strong influence on the bioavailability of hydrophobic organic contaminants. This has important implications for environmental risk assessment, sediment management, and development of novel remediation techniques.

Short-term fate of intertidal microphytobenthos carbon under enhanced nutrient availability: a 13C pulse-chase experiment

NASA Astrophysics Data System (ADS)

Riekenberg, Philip M.; Oakes, Joanne M.; Eyre, Bradley D.

2018-05-01

Shallow coastal waters in many regions are subject to nutrient enrichment. Microphytobenthos (MPB) can account for much of the carbon (C) fixation in these environments, depending on the depth of the water column, but the effect of enhanced nutrient availability on the processing and fate of MPB-derived C (MPB-C) is relatively unknown. In this study, MPB was labeled (stable isotope enrichment) in situ using 13C-sodium bicarbonate. The processing and fate of the newly fixed MPB-C was then traced using ex situ incubations over 3.5 days under different concentrations of nutrients (NH4+ and PO43-: ambient, 2 × ambient, 5 × ambient, and 10 × ambient). After 3.5 days, sediments incubated with increased nutrient concentrations (amended treatments) had increased loss of 13C from sediment organic matter (OM) as a portion of initial uptake (95 % remaining in ambient vs. 79-93 % for amended treatments) and less 13C in MPB (52 % ambient, 26-49 % amended), most likely reflecting increased turnover of MPB-derived C supporting increased production of extracellular enzymes and storage products. Loss of MPB-derived C to the water column via dissolved organic C (DOC) was minimal regardless of treatment (0.4-0.6 %). Loss due to respiration was more substantial, with effluxes of dissolved inorganic C (DIC) increasing with additional nutrient availability (4 % ambient, 6.6-19.8 % amended). These shifts resulted in a decreased turnover time for algal C (419 days ambient, 134-199 days amended). This suggests that nutrient enrichment of estuaries may ultimately lead to decreased retention of carbon within MPB-dominated sediments.

Stabilization of carbon in composts and biochars in relation to carbon sequestration and soil fertility.

PubMed

Bolan, N S; Kunhikrishnan, A; Choppala, G K; Thangarajan, R; Chung, J W

2012-05-01

There have been increasing interests in the conversion of organic residues into biochars in order to reduce the rate of decomposition, thereby enhancing carbon (C) sequestration in soils. However energy is required to initiate the pyrolysis process during biochar production which can also lead to the release of greenhouse gasses. Alternative methods can be used to stabilize C in composts and other organic residues without impacting their quality. The objectives of this study include: (i) to compare the rate of decomposition among various organic amendments and (ii) to examine the effect of clay materials on the stabilization of C in organic amendments. The decomposition of a number of organic amendments (composts and biochars) was examined by monitoring the release of carbon-dioxide using respiration experiments. The results indicated that the rate of decomposition as measured by half life (t(1/2)) varied between the organic amendments and was higher in sandy soil than in clay soil. The half life value ranged from 139 days in the sandy soil and 187 days in the clay soil for poultry manure compost to 9989 days for green waste biochar. Addition of clay materials to compost decreased the rate of decomposition, thereby increasing the stabilization of C. The half life value for poultry manure compost increased from 139 days to 620, 806 and 474 days with the addition of goethite, gibbsite and allophane, respectively. The increase in the stabilization of C with the addition of clay materials may be attributed to the immobilization of C, thereby preventing it from microbial decomposition. Stabilization of C in compost using clay materials did not impact negatively the value of composts in improving soil quality as measured by potentially mineralizable nitrogen and microbial biomass carbon in soil. Copyright © 2012 Elsevier B.V. All rights reserved.

Reactivation of Deep Subsurface Microbial Community in Response to Methane or Methanol Amendment

PubMed Central

Rajala, Pauliina; Bomberg, Malin

2017-01-01

Microbial communities in deep subsurface environments comprise a large portion of Earth’s biomass, but the microbial activity in these habitats is largely unknown. Here, we studied how microorganisms from two isolated groundwater fractures at 180 and 500 m depths of the Outokumpu Deep Drillhole (Finland) responded to methane or methanol amendment, in the presence or absence of sulfate as an additional electron acceptor. Methane is a plausible intermediate in the deep subsurface carbon cycle, and electron acceptors such as sulfate are critical components for oxidation processes. In fact, the majority of the available carbon in the Outokumpu deep biosphere is present as methane. Methanol is an intermediate of methane oxidation, but may also be produced through degradation of organic matter. The fracture fluid samples were incubated in vitro with methane or methanol in the presence or absence of sulfate as electron acceptor. The metabolic response of microbial communities was measured by staining the microbial cells with fluorescent redox sensitive dye combined with flow cytometry, and DNA or cDNA-derived amplicon sequencing. The microbial community of the fracture zone at the 180 m depth was originally considerably more respiratory active and 10-fold more numerous (105 cells ml-1 at 180 m depth and 104 cells ml-1 at 500 m depth) than the community of the fracture zone at the 500 m. However, the dormant microbial community at the 500 m depth rapidly reactivated their transcription and respiration systems in the presence of methane or methanol, whereas in the shallower fracture zone only a small sub-population was able to utilize the newly available carbon source. In addition, the composition of substrate activated microbial communities differed at both depths from original microbial communities. The results demonstrate that OTUs representing minor groups of the total microbial communities play an important role when microbial communities face changes in environmental conditions. PMID:28367144

Bioturbation and dissolved organic matter enhance contaminant fluxes from sediment treated with powdered and granular activated carbon.

PubMed

Kupryianchyk, D; Noori, A; Rakowska, M I; Grotenhuis, J T C; Koelmans, A A

2013-05-21

Sediment amendment with activated carbon (AC) is a promising technique for in situ sediment remediation. To date it is not clear whether this technique sufficiently reduces sediment-to-water fluxes of sediment-bound hydrophobic organic chemicals (HOCs) in the presence of bioturbators. Here, we report polychlorobiphenyl (PCB) pore water concentrations, fluxes, mass transfer coefficients, and survival data of two benthic species, for four treatments: no AC addition (control), powdered AC addition, granular AC addition and addition and subsequent removal of GAC (sediment stripping). AC addition decreased mass fluxes but increased apparent mass transfer coefficients because of dissolved organic carbon (DOC) facilitated transport across the benthic boundary layer (BBL). In turn, DOC concentrations depended on bioturbator activity which was high for the PAC tolerant species Asellus aquaticus and low for AC sensitive species Lumbriculus variegatus. A dual BBL resistance model combining AC effects on gradients, DOC facilitated transport and biodiffusion was evaluated against the data and showed how the type of resistance differs with treatment and chemical hydrophobicity. Data and simulations illustrate the complex interplay between AC and contaminant toxicity to benthic organisms and how differences in species tolerance affect mass fluxes from sediment to the water column.

Biochar

USDA-ARS?s Scientific Manuscript database

Biochar, a carbonaceous material produced by pyrolysis, can be used as soil amendment to improve soil properties. As some of the carbon is converted into a recalcitrant form rendering it more resistant to biodegradation, land application of biochar is promoted as a beneficial mean for carbon sequest...

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

USDA-ARS?s Scientific Manuscript database

In situ application of heavy metal stabilizing agents has in some cases increased the mobility of target metal contaminants. Mechanistic understandings are necessary to better predict (1) the dynamic short- and long-term response to soil amendments, and (2) the utility of biochars in nonremoval and...

Greenhouse gas emission and groundwater pollution potentials of soils amended with raw and carbonized swine solids

USDA-ARS?s Scientific Manuscript database

The objective of this research is to study the greenhouse gas emission and groundwater pollution potentials of the soils amended with raw swine solids and swine biochars made from different thermochemical conditions. Triplicate sets of small pots were designed: 1) control soil with a 50/50 mixture o...

Long-term reactive nitrogen loading alters soil carbon and microbial community properties in a subalpine forest ecosystem

USGS Publications Warehouse

Boot, Claudia M.; Hall, Ed K.; Denef, Karolien; Baron, Jill S.

2016-01-01

Elevated nitrogen (N) deposition due to increased fossil fuel combustion and agricultural practices has altered global carbon (C) cycling. Additions of reactive N to N-limited environments are typically accompanied by increases in plant biomass. Soil C dynamics, however, have shown a range of different responses to the addition of reactive N that seem to be ecosystem dependent. We evaluated the effect of N amendments on biogeochemical characteristics and microbial responses of subalpine forest organic soils in order to develop a mechanistic understanding of how soils are affected by N amendments in subalpine ecosystems. We measured a suite of responses across three years (2011–2013) during two seasons (spring and fall). Following 17 years of N amendments, fertilized soils were more acidic (control mean 5.09, fertilized mean 4.68), and had lower %C (control mean 33.7% C, fertilized mean 29.8% C) and microbial biomass C by 22% relative to control plots. Shifts in biogeochemical properties in fertilized plots were associated with an altered microbial community driven by reduced arbuscular mycorrhizal (control mean 3.2 mol%, fertilized mean 2.5 mol%) and saprotrophic fungal groups (control mean 17.0 mol%, fertilized mean 15.2 mol%), as well as a decrease in N degrading microbial enzyme activity. Our results suggest that decreases in soil C in subalpine forests were in part driven by increased microbial degradation of soil organic matter and reduced inputs to soil organic matter in the form of microbial biomass.

Laboratory evaluation of a reactive baffle approach to NOx control. Final technical report, February-April 1993

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

Nelson, S.G.; Van Stone, D.A.; Little, R.C.

1993-09-01

Vermiculite, vermiculite coated with magnesia, and activated carbon sorbents have successfully removed NOx (and carbon monoxide and particles) from combustion exhausts in a subscale drone jet engine test cell (JETC), but back pressure so generated elevated the temperature of the JETC and of the engine. The objective of this effort was to explore the feasibility of locating the sorbents in the face of the duct or of baffles parallel to the direction of flow within the ducts. Jet engine test cells (JETCs) are stationary sources of oxides of nitrogen (NOx), soot, and unburned or partially oxidized carbon compounds that formmore » as byproducts of imperfect combustion. Regulation of NOx emissions is being considered for implementation under the Clean Air Act Amendments of 1990. Several principles have been examined as candidate methods to control NOx emissions from JETCs.« less

75 FR 75455 - Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil: Final Results of Full...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-03

...-Rolled Carbon-Quality Steel Products From Brazil: Final Results of Full Sunset Review of Countervailing... of the countervailing duty (CVD) order on certain hot-rolled flat-rolled carbon-quality steel products (hot-rolled steel) from Brazil, pursuant to section 751(c) of the Tariff Act of 1930, as amended...

KSCS FOR A PAH AND PCB ASSOCIATED WITH A MARINE SEDIMENT AMENDED WITH SEVERAL TYPES OF SOOT CARBON

EPA Science Inventory

Soot carbon (SC) originates from the combustion of fossil fuels and biomass and is found in sediments around the world. SC comprises up to 30% of organic carbon in sediment and is now commonly recognized as a phase which must be considered when predicting the environmental par...

Soil biochar amendment shapes the composition of N2O-reducing microbial communities.

PubMed

Harter, Johannes; Weigold, Pascal; El-Hadidi, Mohamed; Huson, Daniel H; Kappler, Andreas; Behrens, Sebastian

2016-08-15

Soil biochar amendment has been described as a promising tool to improve soil quality, sequester carbon, and mitigate nitrous oxide (N2O) emissions. N2O is a potent greenhouse gas. The main sources of N2O in soils are microbially-mediated nitrogen transformation processes such as nitrification and denitrification. While previous studies have focused on the link between N2O emission mitigation and the abundance and activity of N2O-reducing microorganisms in biochar-amended soils, the impact of biochar on the taxonomic composition of the nosZ gene carrying soil microbial community has not been subject of systematic study to date. We used 454 pyrosequencing in order to study the microbial diversity in biochar-amended and biochar-free soil microcosms. We sequenced bacterial 16S rRNA gene amplicons as well as fragments of common (typical) nosZ genes and the recently described 'atypical' nosZ genes. The aim was to describe biochar-induced shifts in general bacterial community diversity and taxonomic variations among the nosZ gene containing N2O-reducing microbial communities. While soil biochar amendment significantly altered the 16S rRNA gene-based community composition and structure, it also led to the development of distinct functional traits capable of N2O reduction containing typical and atypical nosZ genes related to nosZ genes found in Pseudomonas stutzeri and Pedobacter saltans, respectively. Our results showed that biochar amendment can affect the relative abundance and taxonomic composition of N2O-reducing functional microbial traits in soil. Thus these findings broaden our knowledge on the impact of biochar on soil microbial community composition and nitrogen cycling. Copyright © 2016 Elsevier B.V. All rights reserved.

40 CFR 91.4 - Acronyms and abbreviations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... CAAA—Clean Air Act Amendments of 1990 CLD—chemiluminescent detector CO—Carbon monoxide CO2—Carbon...—hydrocarbons HCLD—heated chemiluminescent detector HFID—heated flame ionization detector ICI—Independent... OEM—Original engine manufacturer PMD—paramagnetic detector PWC—personal watercraft RPM—revolutions per...

40 CFR 91.4 - Acronyms and abbreviations.

Code of Federal Regulations, 2013 CFR

2013-07-01

... CAAA—Clean Air Act Amendments of 1990 CLD—chemiluminescent detector CO—Carbon monoxide CO2—Carbon...—hydrocarbons HCLD—heated chemiluminescent detector HFID—heated flame ionization detector ICI—Independent... OEM—Original engine manufacturer PMD—paramagnetic detector PWC—personal watercraft RPM—revolutions per...

40 CFR 91.4 - Acronyms and abbreviations.

Code of Federal Regulations, 2014 CFR

2014-07-01

... CAAA—Clean Air Act Amendments of 1990 CLD—chemiluminescent detector CO—Carbon monoxide CO2—Carbon...—hydrocarbons HCLD—heated chemiluminescent detector HFID—heated flame ionization detector ICI—Independent... OEM—Original engine manufacturer PMD—paramagnetic detector PWC—personal watercraft RPM—revolutions per...

40 CFR 91.4 - Acronyms and abbreviations.

Code of Federal Regulations, 2011 CFR

2011-07-01

... CAAA—Clean Air Act Amendments of 1990 CLD—chemiluminescent detector CO—Carbon monoxide CO2—Carbon...—hydrocarbons HCLD—heated chemiluminescent detector HFID—heated flame ionization detector ICI—Independent... OEM—Original engine manufacturer PMD—paramagnetic detector PWC—personal watercraft RPM—revolutions per...

40 CFR 91.4 - Acronyms and abbreviations.

Code of Federal Regulations, 2012 CFR

2012-07-01

... CAAA—Clean Air Act Amendments of 1990 CLD—chemiluminescent detector CO—Carbon monoxide CO2—Carbon...—hydrocarbons HCLD—heated chemiluminescent detector HFID—heated flame ionization detector ICI—Independent... OEM—Original engine manufacturer PMD—paramagnetic detector PWC—personal watercraft RPM—revolutions per...

Changes in heavy metal mobility and availability from contaminated wetland soil remediated with combined biochar-compost.

PubMed

Liang, Jie; Yang, Zhaoxue; Tang, Lin; Zeng, Guangming; Yu, Man; Li, Xiaodong; Wu, Haipeng; Qian, Yingying; Li, Xuemei; Luo, Yuan

2017-08-01

The combination of biochar and compost has been proven to be effective in heavy metals contaminated wetland soil restoration. However, the influence of different proportions between biochar and compost on immobilization of heavy metals in soil has been less studied up to date. Therefore, we investigated the effect of different ratios of biochar-compost mixtures on availability and speciation distribution of heavy metals (Cd, Zn and Cu) in wetland soil. The results showed that applying all amendment combinations into wetland soil increased gradually the total organic carbon (TOC) and water-extract organic carbon (WEOC) as the compost percentage rose in biochar-composts. The higher pH was obtained in a certain biochar addition (20% and 40%) in combinations due to efficient interaction of biochar with compost. All amendments could significantly decrease availability of Cd and Zn mainly from pH change, but increase available Cu concentration as the result of increased water-extract organic carbon and high total Cu content in compost. Moreover, amendments can decrease easily exchangeable fraction and increase reducible of Cd and Zn greatly with increase of compost content in combinations, while amendments containing compost promote transformation of Cu from Fe/Mn oxide and residual fractions to organic bindings. These results demonstrate that different ratios of biochar and compost have a significant effect on availability and speciation of heavy metals in multi-metal-contaminated wetland soil. Copyright © 2017 Elsevier Ltd. All rights reserved.

Bioretention Design to Improve Nitrogen Removal | Science ...

EPA Pesticide Factsheets

Bioretention has been shown to effectively remove a variety of stormwater stressors, including oil/grease, heavy metals, phosphorus, and ammonium. However, reported nitrate and total nitrogen removal performance is highly variable. The media typically used in bioretention installation is coarse-grained with low organic matter content, which facilitates high infiltration rates but fails to provide the anaerobic conditions and carbon availability necessary to promote nitrate removal by denitrification. EPA's research at the Urban Watershed Research Facility investigates the effects of media carbon amendments, introduced internal storage zones, plant type, and media volume on nitrogen removal. Initial bench-scale tests informed media and carbon amendment choices. A locally-available, sandy media with low organic matter content was added to eight experimental, pilot-scale rain gardens above a shallow pea gravel drainage layer. The media was separated from the pea gravel with a nonwoven geotextile. Double-shredded hardwood wood chips were chosen as a carbon amendment and added as a 20-cm layer 10 cm above the geotextile in four of the eight pilot-scale rain gardens; the other four did not receive the mulch layer. Four rain gardens were constructed with an elevated outlet pipe to create an internal storage zone; the other four drain freely. Pilot-scale rain gardens were constructed in tanks of two sizes to test the effects of media volume. After initial hydrologic

Dissolved Organic Carbon Degradation in Response to Nutrient Amendments in Southwest Greenland Lakes

NASA Astrophysics Data System (ADS)

Burpee, B. T.; Northington, R.; Simon, K. S.; Saros, J. E.

2014-12-01

Aquatic ecosystems across the Arctic are currently experiencing rapid shifts in biotic, chemical, and physical factors in response to climate change. Preliminary data from multiple lakes in southwestern Greenland indicate decreasing dissolved organic carbon (DOC) concentrations over the past decade. Though several factors may be contributing to this phenomenon, this study attempts to elucidate the potential of heterotrophic bacteria to degrade DOC in the presence of increasing nutrient concentrations. In certain Arctic regions, nutrient subsidies have been released into lakes due to permafrost thaw. If this is occurring in southwestern Greenland, we hypothesized that increased nutrient concentrations will relieve nutrient limitation, thereby allowing heterotrophic bacteria to utilize DOC as an energy source. This prediction was tested using experimental DOC degradation assays from four sample lakes. Four nutrient amendment treatments (control, N, P, and N + P) were used to simulate in situ subsidies. Five time points were sampled during the incubation: days 0, 3, 6, 14, and 60. Total organic carbon (TOC) and parallel factor (PARAFAC) analysis were used to monitor the relative concentrations of different DOC fractions over time. In addition, samples for extracellular enzyme activity (EEA) analysis were collected at every time point. Early analysis of fulvic and humic pools of DOC do not indicate any significant change from days 0 to 14. This could be due to the fact that these DOC fractions are relatively recalcitrant. This study will be important in determining whether bacterial degradation could be a contributing factor to DOC decline in arctic lakes.

Reductive dechlorination of chlorobenzenes in surfactant-amended sediment slurries

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

Van Hoof, P.L.; Jafvert, C.T.

1996-11-01

Microbial anaerobic dechlorination of hexachlorobenzene (HCB) was examined in sediment slurries amended with two classes of nonionic surfactant, polyoxyethylene (POE) sorbitan fatty acid esters (Tweens) and POE alcohols (Brijs). The rationale for surfactant addition was to increase the bioavailability of highly sorbed organic pollutants to degrading microorganisms by enhancing their solubility. The solubility of HCB was initially enhanced via micellar partitioning; however, primary degradation of most surfactants occurred within 10 d. Dechlorination activity was significantly reduced at POE alcohol concentrations above the critical micelle concentration (cmc), with or without the occurrence of surfactant degradation. Tween 80 decreased HCB dechlorination atmore » concentrations significantly above the cmc. At concentrations closer to the cmc, Tween 80 increased dechlorination rate constants four- to fivefold in acclimated slurries. Additions of Tween 80 at or below the cmc stimulated dechlorination activity in unacclimated slurries that exhibited very little activity in unamended controls. An average of 89% of HCB was dechlorinated after 90 d, compared to 20% in unamended sediments. No effect was observed for POE alcohols at these sub-cmc levels. The lack of a stimulated response for the POE alcohols suggests that Tween 80 may not be acting simply as a source of carbon or energy.« less

Utilizing thin-film solid-phase extraction to assess the effect of organic carbon amendments on the bioavailability of DDT and dieldrin to earthworms

USGS Publications Warehouse

Andrade, Natasha A.; Centofanti, Tiziana; McConnell, Laura L.; Hapeman, Cathleen J.; Torrents, Alba; Anh, Nguyen; Beyer, W. Nelson; Chaney, Rufus L.; Novak, Jeffrey M.; Anderson, Marya O.; Cantrell, Keri B.

2014-01-01

Improved approaches are needed to assess bioavailability of hydrophobic organic compounds in contaminated soils. Performance of thin-film solid-phase extraction (TF-SPE) using vials coated with ethylene vinyl acetate was compared to earthworm bioassay (Lumbricus terrestris). A DDT and dieldrin contaminated soil was amended with four organic carbon materials to assess the change in bioavailability. Addition of organic carbon significantly lowered bioavailability for all compounds except for 4,4′-DDT. Equilibrium concentrations of compounds in the polymer were correlated with uptake by earthworms after 48d exposure (R2 = 0.97; p 40yr of aging. Results show that TF-SPE can be useful in examining potential risks associated with contaminated soils and to test effectiveness of remediation efforts.

Sweet sorghum bagasse for production of biochar

USDA-ARS?s Scientific Manuscript database

Sweet sorghum bagasse is an untapped resourceful carbon-rich material that can be thermochemically converted into value-added biochars. These biochars can be applied to the field as soil amendment for soil health enhancement, improved soil carbon content, water holding capacity, soil drainage and a...

Carrot, Corn, Lettuce and Soybean Nutrient Contents are Affected by Biochar

EPA Science Inventory

Biochar, the carbon-rich material remaining after pyrolysis of cellulosic and manure feedstocks, has the potential as a soil amendment to sequester carbon and to improve soil water-holding and nutrient properties- thereby enhancing plant growth. However, biochar produced from so...

Biochar Treatment Resulted in a Combined Effect on Soybean Growth Promotion and a Shift in Plant Growth Promoting Rhizobacteria

PubMed Central

Egamberdieva, Dilfuza; Wirth, Stephan; Behrendt, Undine; Abd_Allah, Elsayed F.; Berg, Gabriele

2016-01-01

The application of biochar to soil is considered to have the potential for long-term soil carbon sequestration, as well as for improving plant growth and suppressing soil pathogens. In our study we evaluated the effect of biochar on the plant growth of soybeans, as well as on the community composition of root-associated bacteria with plant growth promoting traits. Two types of biochar, namely, maize biochar (MBC), wood biochar (WBC), and hydrochar (HTC) were used for pot experiments to monitor plant growth. Soybean plants grown in soil amended with HTC char (2%) showed the best performance and were collected for isolation and further characterization of root-associated bacteria for multiple plant growth promoting traits. Only HTC char amendment resulted in a statistically significant increase in the root and shoot dry weight of soybeans. Interestingly, rhizosphere isolates from HTC char amended soil showed higher diversity than the rhizosphere isolates from the control soil. In addition, a higher proportion of isolates from HTC char amended soil compared with control soil was found to express plant growth promoting properties and showed antagonistic activity against one or more phytopathogenic fungi. Our study provided evidence that improved plant growth by biochar incorporation into soil results from the combination of a direct effect that is dependent on the type of char and a microbiome shift in root-associated beneficial bacteria. PMID:26941730

76 FR 28419 - Certain Hot-Rolled Carbon Steel Flat Products From India: Notice of Extension of Time Limit for...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-17

... DEPARTMENT OF COMMERCE International Trade Administration [A-533-820] Certain Hot-Rolled Carbon...-rolled carbon steel flat products from India for the period December 1, 2008, through November 30, 2009... September 14, 2010, in accordance with section 751(a)(3)(A) of the Tariff Act of 1930, as amended (the Act...

Evaluation of different methods for assessing bioavailability of DDT residues during soil remediation.

PubMed

Wang, Jie; Taylor, Allison; Xu, Chenye; Schlenk, Daniel; Gan, Jay

2018-07-01

Compared to the total chemical concentration, bioavailability is a better measurement of risks of hydrophobic organic contaminants (HOCs) to biota in contaminated soil or sediment. Many different bioavailability estimation methods have been introduced to assess the effectiveness of remediation treatments. However, to date the different methods have rarely been evaluated against each other, leading to confusions in method selection. In this study, four different bioavailability estimation methods, including solid phase microextraction (SPME) and polyethylene passive sampling (PE) aiming to detect free chemical concentration (C free ), and Tenax desorption and isotope dilution method (IDM) aiming to measure chemical accessibility, were used in parallel to estimate in bioavailability of DDT residues (DDXs) in a historically contaminated soil after addition of different black carbon sorbents. Bioaccumulation into earthworm (Eisenia fetida) was measured concurrently for verification. Activated carbon or biochar amendment at 0.2-2% decreased earthworm bioaccumulation of DDXs by 83.9-99.4%, while multi-walled carbon nanotubes had a limited effect (4.3-20.7%). While all methods correctly predicted changes in DDX bioavailability after black carbon amendment, passive samplers offered more accurate predictions. Predicted levels of DDXs in earthworm lipid using the estimated bioavailability and empirical BCFs matched closely with the experimentally derived tissue concentrations. However, Tenax and IDM overestimated bioavailability when the available DDX levels were low. Our findings suggested that both passive samplers and bioaccessibility methods can be used in assessing remediation efficiency, presenting flexibility in method selection. While accessibility-oriented methods offer better sensitivity and shorter sampling time, passive samplers may be more advantageous because of their better performance and computability for in situ deployment. Copyright © 2018 Elsevier Ltd. All rights reserved.

State and solubility of cadmium as related to xenotic inorganic phases generated homogeneously in soils

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

Walker, W.J.

The state and solubility of cadmium in waste-treated soils was investigated. Three sets of experiments were designed to elucidate solid phase control of soil solution cadmium. First, the soil solution composition of two soils amended with either sludge or metal contaminated mulch was examined to determine the presence of anions capable of precipitating or co-precipitating cadmium. Results indicated that no known pure solid phases of cadmium developed but that high concentrations of phosphate, sulfate and carbonate apparently influenced cadmium solubility. Secondly, three soils were amended with 10 ug of cadmium as cadmium acetate/g of soil. Three different levels of glycerophosphate,more » cysteine and acetate were added to the soils and incubated at constant temperature and water content in order to release phosphate, sulfate and alkalinity under conditions conducive for homogeneous precipitation. Another set of treatments was prepared in the same fashion with an additional amendment of calcium carbonate to raise soil pH's to 7.0. In the presence of sulfate, cadmium solubility increased with no apparent solid phase formation. The addition of calcium carbonate shifted solid phase control to either calcium carbonate or calcium sulfate. The generation of alkalinity by acetate addition produced solid phase calcium carbonate which in turn controlled cadmium solubility through chemisorption of cadmium on calcite surfaces. In the presence of monobasic calcium phosphate, cadmium was interfacially adsorbed. In the presence of dibasic calcium phosphate, however, cadmium was homogeneously precipitated in the host crystal suggesting possible solid solution.« less

Prokaryotic Responses to Ammonium and Organic Carbon Reveal Alternative CO2 Fixation Pathways and Importance of Alkaline Phosphatase in the Mesopelagic North Atlantic

PubMed Central

Baltar, Federico; Lundin, Daniel; Palovaara, Joakim; Lekunberri, Itziar; Reinthaler, Thomas; Herndl, Gerhard J.; Pinhassi, Jarone

2016-01-01

To decipher the response of mesopelagic prokaryotic communities to input of nutrients, we tracked changes in prokaryotic abundance, extracellular enzymatic activities, heterotrophic production, dark dissolved inorganic carbon (DIC) fixation, community composition (16S rRNA sequencing) and community gene expression (metatranscriptomics) in 3 microcosm experiments with water from the mesopelagic North Atlantic. Responses in 3 different treatments amended with thiosulfate, ammonium or organic matter (i.e., pyruvate plus acetate) were compared to unamended controls. The strongest stimulation was found in the organic matter enrichments, where all measured rates increased >10-fold. Strikingly, in the organic matter treatment, the dark DIC fixation rates—assumed to be related to autotrophic metabolisms—were equally stimulated as all the other heterotrophic-related parameters. This increase in DIC fixation rates was paralleled by an up-regulation of genes involved in DIC assimilation via anaplerotic pathways. Alkaline phosphatase was the metabolic rate most strongly stimulated and its activity seemed to be related to cross-activation by nonpartner histidine kinases, and/or the activation of genes involved in the regulation of elemental balance during catabolic processes. These findings suggest that episodic events such as strong sedimentation of organic matter into the mesopelagic might trigger rapid increases of originally rare members of the prokaryotic community, enhancing heterotrophic and autotrophic carbon uptake rates, ultimately affecting carbon cycling. Our experiments highlight a number of fairly unstudied microbial processes of potential importance in mesopelagic waters that require future attention. PMID:27818655

Amending the Structure of Renewable Carbon from Biorefinery Waste-Streams for Energy Storage Applications

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

Ho, Hoi Chun; Goswami, Monojoy; Chen, Jihua

Biorefineries produce impure sugar waste streams that are being underutilized. By converting this waste to a profitable by-product, biorefineries could be safeguarded against low oil prices. We demonstrate controlled production of useful carbon materials from the waste concentrate via hydrothermal synthesis and carbonization. We devise a pathway to producing tunable, porous spherical carbon materials by modeling the gross structure formation and developing an understanding of the pore formation mechanism utilizing simple reaction principles. Compared to a simple hydrothermal synthesis from sugar concentrate, emulsion-based synthesis results in hollow spheres with abundant microporosity. In contrast, conventional hydrothermal synthesis produces solid beads withmore » micro and mesoporosity. All the carbonaceous materials show promise in energy storage application. Using our reaction pathway, perfect hollow activated carbon spheres can be produced from waste sugar in liquid effluence of biomass steam pretreatment units. As a result, the renewable carbon product demonstrated a desirable surface area of 872 m 2/g and capacitance of up to 109 F/g when made into an electric double layer supercapacitor. The capacitor exhibited nearly ideal capacitive behavior with 90.5% capacitance retention after 5000 cycles.« less

Amending the Structure of Renewable Carbon from Biorefinery Waste-Streams for Energy Storage Applications

DOE PAGES

Ho, Hoi Chun; Goswami, Monojoy; Chen, Jihua; ...

2018-05-29

Biorefineries produce impure sugar waste streams that are being underutilized. By converting this waste to a profitable by-product, biorefineries could be safeguarded against low oil prices. We demonstrate controlled production of useful carbon materials from the waste concentrate via hydrothermal synthesis and carbonization. We devise a pathway to producing tunable, porous spherical carbon materials by modeling the gross structure formation and developing an understanding of the pore formation mechanism utilizing simple reaction principles. Compared to a simple hydrothermal synthesis from sugar concentrate, emulsion-based synthesis results in hollow spheres with abundant microporosity. In contrast, conventional hydrothermal synthesis produces solid beads withmore » micro and mesoporosity. All the carbonaceous materials show promise in energy storage application. Using our reaction pathway, perfect hollow activated carbon spheres can be produced from waste sugar in liquid effluence of biomass steam pretreatment units. As a result, the renewable carbon product demonstrated a desirable surface area of 872 m 2/g and capacitance of up to 109 F/g when made into an electric double layer supercapacitor. The capacitor exhibited nearly ideal capacitive behavior with 90.5% capacitance retention after 5000 cycles.« less

Simultaneous production of l-lactic acid with high optical activity and a soil amendment with food waste that demonstrates plant growth promoting activity.

PubMed

Kitpreechavanich, Vichien; Hayami, Arisa; Talek, Anfal; Chin, Clament Fui Seung; Tashiro, Yukihiro; Sakai, Kenji

2016-07-01

A unique method to produce highly optically-active l-lactic acid and soil amendments that promote plant growth from food waste was proposed. Three Bacillus strains Bacillus subtilis KBKU21, B. subtilis N3-9 and Bacillus coagulans T27, were used. Strain KBKU21 accumulated 36.9 g/L l-lactic acid with 95.7% optical activity and 98.2% l-lactic acid selectivity when fermented at 43°C for 84 h in a model kitchen refuse (MKR) medium. Residual precipitate fraction (anaerobically-fermented MKR (AFM) compost) analysis revealed 4.60%, 0.70% and 0.75% of nitrogen (as N), phosphorous (as P2O5), and potassium (as K2O), respectively. Additionally, the carbon to nitrogen ratio decreased from 13.3 to 10.6. AFM compost with KBKU21 promoted plant growth parameters, including leaf length, plant height and fresh weight of Brassica rapa (Komatsuna), than that by chemical fertilizers or commercial compost. The concept provides an incentive for the complete recycling of food waste, contributing towards a sustainable production system. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Pesticide mobility and leachate toxicity in two abandoned mine soils. Effect of organic amendments.

PubMed

Rodríguez-Liébana, José Antonio; Mingorance, M Dolores; Peña, Aránzazu

2014-11-01

Abandoned mine areas, used in the past for the extraction of minerals, constitute a degraded landscape which needs to be reintegrated to productive or leisure activities. However these soils, mainly composed by silt or sand and with low organic matter content, are vulnerable to organic and inorganic pollutants posing a risk to the surrounding ecosystems and groundwater. Soils from two mining areas from Andalusia were evaluated: one from Nerva (NCL) in the Iberian Pyrite Belt (SW Andalusia) and another one from the iron Alquife mine (ALQ) (SE Andalusia). To improve soil properties and fertility two amendments, stabilised sewage sludge (SSL) and composted sewage sludge (CSL), were selected. The effect of amendment addition on the mobility of two model pesticides, thiacloprid and fenarimol, was assessed using soil columns under non-equilibrium conditions. Fenarimol, more hydrophobic than thiacloprid, only leached from native ALQ, a soil with lower organic carbon (OC) content than NCL (0.21 and 1.4%, respectively). Addition of amendments affected differently pesticide mobility: thiacloprid in the leachates was reduced by 14% in NCL-SSL and by 4% in ALQ-CSL. Soil OC and dissolved OC were the parameters which explained pesticide residues in soil. Chemical analysis revealed that leachates from the different soil columns did not contain toxic element levels, except As in NCL soil. Finally ecotoxicological data showed moderate toxicity in the initial leachates, with an increase coinciding with pesticide maximum concentration. The addition of SSL slightly reduced the toxicity towards Vibrio fischeri, likely due to enhanced retention of pesticides by amended soils. Copyright © 2014 Elsevier B.V. All rights reserved.

Effects of Biochar Feedstock and Pyrolysis Temperature on Growth of Corn, Soybean, Lettuce and Carrot

EPA Science Inventory

Biochar, the carbon-rich material remaining after pyrolysis (low oxygen) of cellulosic feedstocks, has the potential as a soil amendment to sequester carbon, improve soil water-holding capacity, and increase nutrient retention thereby enhancing soil conditions to benefit plant gr...

Conversion of sweet sorghum bagasse into value-added biochar

USDA-ARS?s Scientific Manuscript database

Sweet sorghum bagasse is an untapped resourceful carbon-rich material that can be thermochemically converted into value-added biochars. These biochars can be applied to the field as soil amendment for soil health enhancement, improved soil carbon content, water holding capacity, soil drainage and a...

Field-scale fluorescence fingerprinting of biochar-borne dissolved organic carbon

USDA-ARS?s Scientific Manuscript database

Biochar continues to receive worldwide enthusiasm as means of augmenting recalcitrant organic carbon in agricultural soils. Realistic biochar amendment rate (typically less than 1 wt%) in the field scale, and loss by sizing, rain, and other transport events demand reliable methods to quantify the r...

Field evaluation of intensive compost application on Cd fractionation and phytoavailability in a mining-contaminated soil.

PubMed

Li, Ming; Mohamed, Ibrahim; Raleve, David; Chen, Wenli; Huang, Qiaoyun

2016-10-01

A field experiment was conducted to investigate the effect of chicken manure compost on the fractionation of cadmium (Cd), soil biological properties and Cd uptake by wheat in a soil affected by mining activities in Hubei province, China. Compost was applied at five levels (0, 27, 54, 108, 216 t ha(-1)), and winter wheat (Triticum aestivum L.) was chosen as an indicator plant. Results showed that the application of compost increased soil pH and the content of total phosphorus and organic matter. Soil biological properties such as microbial biomass carbon, invertase, protease, urease and catalase activities were significantly enhanced by 0.24-3.47 times after compost application. Sequential extraction indicated that compost amendments decreased the acid-extractable Cd by 8.2-37.6 %, while increased the reducible and oxidisable Cd by 9.2-39.5 and 8.2-60.4 %, respectively. The addition of 27-54 t ha(-1) compost reduced Cd content in wheat stems and seeds by 69.6-75.0 % and 10.3-18.4 %, respectively. However, only 25.5-26.5 % reductions in Cd content in wheat stems were observed in 108-216 t ha(-1) compost amendments, and no significant decrease was detected for seeds. This study suggests that although compost is a suitable organic amendment to improve soil fertility and biological activities, the addition of compost should be moderated by an appropriate rate to optimize the use of compost for the reclamation of metal-contaminated soils at field scale.

Long-term climate change mitigation potential with organic matter management on grasslands.

PubMed

Ryals, Rebecca; Hartman, Melannie D; Parton, William J; DeLonge, Marcia S; Silver, Whendee L

2015-03-01

Compost amendments to grasslands have been proposed as a strategy to mitigate climate change through carbon (C) sequestration, yet little research exists exploring the net mitigation potential or the long-term impacts of this strategy. We used field data and the DAYCENT biogeochemical model to investigate the climate change mitigation potential of compost amendments to grasslands in California, USA. The model was used to test ecosystem C and greenhouse gas responses to a range of compost qualities (carbon to nitrogen [C:N] ratios of 11.1, 20, or 30) and application rates (single addition of 14 Mg C/ha or 10 annual additions of 1.4 Mg C · ha(-1) · yr(-1)). The model was parameterized using site-specific weather, vegetation, and edaphic characteristics and was validated by comparing simulated soil C, nitrous oxide (N2O), methane (CH4), and carbon dioxide (CO2) fluxes, and net primary production (NPP) with three years of field data. All compost amendment scenarios led to net greenhouse gas sinks that persisted for several decades. Rates of climate change mitigation potential ranged from 130 ± 3 g to 158 ± 8 g CO2-eq · m(-2) ·yr(-1) (where "eq" stands for "equivalents") when assessed over a 10-year time period and 63 ± 2 g to 84 ± 10 g CO2- eq · m(-2) · yr(-1) over a 30-year time period. Both C storage and greenhouse gas emissions increased rapidly following amendments. Compost amendments with lower C:N led to higher C sequestration rates over time. However, these soils also experienced greater N20 fluxes. Multiple smaller compost additions resulted in similar cumulative C sequestration rates, albeit with a time lag, and lower cumulative N2O emissions. These results identify a trade-off between maximizing C sequestration and minimizing N2O emissions following amendments, and suggest that compost additions to grassland soils can have a long-term impact on C and greenhouse gas dynamics that contributes to climate change mitigation.

Soil properties, greenhouse gas emissions and crop yield under compost, biochar and co-composted biochar in two tropical agronomic systems.

PubMed

Bass, Adrian M; Bird, Michael I; Kay, Gavin; Muirhead, Brian

2016-04-15

The addition of organic amendments to agricultural soils has the potential to increase crop yields, reduce dependence on inorganic fertilizers and improve soil condition and resilience. We evaluated the effect of biochar (B), compost (C) and co-composted biochar (COMBI) on the soil properties, crop yield and greenhouse gas emissions from a banana and a papaya plantation in tropical Australia in the first harvest cycle. Biochar, compost and COMBI organic amendments improved soil properties, including significant increases in soil water content, CEC, K, Ca, NO3, NH4 and soil carbon content. However, increases in soil nutrient content and improvements in physical properties did not translate to improved fruit yield. Counter to our expectations, banana crop yield (weight per bunch) was reduced by 18%, 12% and 24% by B, C and COMBI additions respectively, and no significant effect was observed on the papaya crop yield. Soil efflux of CO2 was elevated by addition of C and COMBI amendments, likely due to an increase in labile carbon for microbial processing. Our data indicate a reduction in N2O flux in treatments containing biochar. The application of B, C and COMBI amendments had a generally positive effect on soil properties, but this did not translate into a crop productivity increase in this study. The benefits to soil nutrient content, soil carbon storage and N2O emission reduction need to be carefully weighed against potentially deleterious effects on crop yield, at least in the short-term. Copyright © 2016 Elsevier B.V. All rights reserved.

Influence of carbon source amendment on effectiveness of anaerobic soil disinfestation

USDA-ARS?s Scientific Manuscript database

Anaerobic soil disinfestation (ASD; also termed biological soil disinfestation or soil reductive sterilization) is a non-chemical soil disinfestation process which includes 1) soil incorporation of a labile carbon (C) source, 2) mulching with a polyethylene film to limit gas exchange, and 3) drip ir...

Carbon Mineralization in Two Ultisols Amended with Different Sources and Particle Sizes of Pyrolyzed Biochar

EPA Science Inventory

Biochar produced during pyrolysis has the potential to enhance soil fertility and reduce greenhouse gas emissions. The influence of biochar properties (e.g., particle size) on both short- and long-term carbon (C) mineralization of biochar remains unclear. There is minimal informa...

75 FR 8431 - Carbon Dioxide Fire Suppression Systems on Commercial Vessels

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-24

... Fire Suppression Systems on Commercial Vessels; Proposed Rule #0;#0;Federal Register / Vol. 75 , No. 36... 1625-AB44 Carbon Dioxide Fire Suppression Systems on Commercial Vessels AGENCY: Coast Guard, DHS... for fire suppression systems on several classes of commercial vessels. The amendments would clarify...

Kim Magrini | NREL

Science.gov Websites

Developing char-based soil amendments Soil carbon and char analysis via molecular beam mass spectrometry depth profiling, Fourier transform infrared [FTIR]) Rapid soil carbon analysis using analytical DRIFTS, 13C NMR, and py-MBMS to Characterize the Effects of Soil Science Oxidation Assays on Soil Organic

Abiotic and Biotic Effect of Poultry Litter Biochar on Ammonia Removal

USDA-ARS?s Scientific Manuscript database

In the era of climate change, conversion of raw materials such as crop residuals and other waste byproducts into biochar could serve as a sink for carbon sequestration which could help reduce carbon footprint in the atmospheric environment. Biochar could also be used for soil amendment to improve ...

Influence of Biochar on Soil pH, Water Holding Capacity, Nitrogen and Carbon Dynamics

USDA-ARS?s Scientific Manuscript database

The recent focus of biochar as a soil amendment for improving soil physical-chemical properties and carbon sequestration has revealed knowledge gaps in the research covering different feedstocks in various soil types. Biochars made from four feedstocks (wood pellets [Pseudotsuga menziesii], softw...

Pyrolysis temperature-dependent release of dissolved organic carbon from plant, manure, and biorefinery wastes

USDA-ARS?s Scientific Manuscript database

Limited information is available to understand the chemical structure of biochar’s labile dissolved organic carbon (DOC) fraction that will change amended soil’s DOC composition. This study utilized the high sensitivity of fluorescence excitation-emission (EEM) spectrophotometry to understand the s...

Evaluation of carbon and nitrogen pools in different soil types amended with different organic inputs by thermogravimetric/calorimetric analysis

NASA Astrophysics Data System (ADS)

Yanardaǧ, Ibrahim H.; Zornoza, Raúl; Büyükkiliç-Yanardaǧ, Asuman; Acosta, Jose A.; Faz, Ángel; Mermut, Ahmet R.

2017-04-01

The objective of this study was to assess the short-term changes in soil organic C (SOC) and N pools after incubation of three different soil types (Regosol, Luvisol and Kastanozem) treated with three amendments differing in organic matter stability (raw pig slurry (PS), manure, and biochar (BC), and to establish relationships between different chemical, spectral and thermal/calorimetric data to assess if thermal/calorimetric analysis could replace conventional analyses to monitor changes in SOC and N poos. Thermogravimetry-Differential Scanning Calorimetry (TG-DSC) analysis showed that amendments had little effect on volatile SOC and inorganic matter, compared to unamended samples in all soils. All amendments significantly increased the labile SOC in Regosol. Manure and BC increased recalcitrant SOC in Regosol and Luvisol. BC significantly increased recalcitrant SOC in all soils. Refractory SOC slightly increased with amendments in the Luvisol compared to the control. These results support the findings obtained with chemical analyses. Selected evolved ions (m/z 30 and 44) detected by quadrupole mass spectrometry (QMS) confirmed findings from TG-DSC. Emissions of C and N containing gases from the Regosol significantly increased with the amendments because this soil contains low SOC content, and the application of these amendments provided additional C. An increase in the CO2 containing gas species (m/z 44) from volatile SOC was observed with PS application only in the Regosol. Carbon dioxide increments (m/z 44) from recalcitrant (380-475°C) and refractory (475-550/600°C) SOC pools were observed with all amendments in all soils especially with BC application. The evolved ions at m/z 44 were higher in the initial soil samples from Kastanozem than after incubation, suggesting a loss of organic compounds, mainly volatile and labile upon incubation. NO peaks (m/z 30) showed similar trends to the C containing gas species in all soils. We carried out linear regressions to estimate soil properties measured by conventional chemical procedures by the use of TG-DSC-QMS. We obtained accurate models to estimate SOC, soil carbonates, recalcitrant C, soluble C and soluble N. These results encourage the use of thermal analyses to study SOM dynamics in soils, since it provides feasible and accurate information about different organic and inorganic C and N fractions. Thermal methods are quite inexpensive, require little sample preparation, are rapid and give reproducible results. However, no relationship between thermal analyses and C and N mineralization and N volatilization was found, suggesting that this technique may be valid to assess the current value of different organic fractions in a soil in a concrete time, but not indicated to predict mineralization or volatilization trends after application of amendments.

Impacts of zeolite, alum and polyaluminum chloride amendments mixed with agricultural wastes on soil column leachate, and CO2 and CH4 emissions.

PubMed

Murnane, J G; Fenton, O; Healy, M G

2018-01-15

This study aimed to quantify leaching losses of nitrogen (N), phosphorus (P) and carbon (C), as well as carbon dioxide (CO 2 ) and methane (CH 4 ) emissions from stored slurry, and from packed soil columns surface applied with unamended and chemically amended dairy and pig slurries, and dairy soiled water (DSW). The amendments to the slurries, which were applied individually and together, were: polyaluminum chloride (PAC) and zeolite for pig and dairy slurry, and liquid aluminium sulfate (alum) and zeolite for DSW. Application of pig slurry resulted in the highest total nitrogen (TN) and nitrate-nitrogen (NO 3 -N) fluxes (22 and 12 kg ha -1 ), whereas corresponding fluxes from dairy slurries and DSW were not significantly (p < 0.05) higher than those from the control soil. There were no significant (p < 0.05) differences in leachate N losses between unamended and amended dairy slurries, unamended and amended pig slurries, and unamended and amended DSW. There were no leachate P losses measured over the experimental duration. Total cumulative organic (TOC) and inorganic C (TIC) losses in leachate were highest for unamended dairy slurry (82 and 142 kg ha -1 ), and these were significantly (p < 0.05) reduced when amended with PAC (38 and 104 kg ha -1 ). The highest average cumulative CO 2 emissions for all treatments were measured for pig slurries (680 kg CO 2 -C ha -1 ) followed by DSW (515 kg CO 2 -C ha -1 ) and dairy slurries (486 kg CO 2 -C ha -1 ). The results indicate that pig slurry, either in raw or chemically amended form, poses the greatest environmental threat of leaching losses and gaseous emissions of CO 2 and CH 4 and, in general, amendment of wastewater with PAC, alum or zeolite, does not mitigate the risk of these losses. Copyright © 2017 Elsevier Ltd. All rights reserved.

Assessing the influence of compost and biochar amendments on the mobility and toxicity of metals and arsenic in a naturally contaminated mine soil.

PubMed

Beesley, Luke; Inneh, Onyeka S; Norton, Gareth J; Moreno-Jimenez, Eduardo; Pardo, Tania; Clemente, Rafael; Dawson, Julian J C

2014-03-01

Amending contaminated soils with organic wastes can influence trace element mobility and toxicity. Soluble concentrations of metals and arsenic were measured in pore water and aqueous soil extracts following the amendment of a heavily contaminated mine soil with compost and biochar (10% v:v) in a pot experiment. Speciation modelling and toxicity assays (Vibrio fischeri luminescence inhibition and Lolium perenne germination) were performed to discriminate mechanisms controlling metal mobility and assess toxicity risk thereafter. Biochar reduced free metal concentrations furthest but dissolved organic carbon primarily controlled metal mobility after compost amendment. Individually, both amendments induced considerable solubilisation of arsenic to pore water (>2500 μg l(-1)) related to pH and soluble phosphate but combining amendments most effectively reduced toxicity due to simultaneous reductions in extractable metals and increases in soluble nutrients (P). Thus the measure-monitor-model approach taken determined that combining the amendments was most effective at mitigating attendant toxicity risk. Copyright © 2013 Elsevier Ltd. All rights reserved.

The effects of worms, clay and biochar on CO2 emissions during production and soil application of co-composts

NASA Astrophysics Data System (ADS)

Barthod, Justine; Rumpel, Cornélia; Paradelo, Remigio; Dignac, Marie-France

2016-12-01

In this study we evaluated CO2 emissions during composting of green wastes with clay and/or biochar in the presence and absence of worms (species of the genus Eisenia), as well as the effect of those amendments on carbon mineralization after application to soil. We added two different doses of clay, biochar or their mixture to pre-composted green wastes and monitored carbon mineralization over 21 days in the absence or presence of worms. The resulting co-composts and vermicomposts were then added to a loamy Cambisol and the CO2 emissions were monitored over 30 days in a laboratory incubation. Our results indicated that the addition of clay or clay/biochar mixture reduced carbon mineralization during co-composting without worms by up to 44 %. In the presence of worms, CO2 emissions during composting increased for all treatments except for the low clay dose. The effect of the amendments on carbon mineralization after addition to soil was small in the short term. Overall, composts increased OM mineralization, whereas vermicomposts had no effect. The presence of biochar reduced OM mineralization in soil with respect to compost and vermicompost without additives, whereas clay reduced mineralization only in the composts. Our study indicates a significant role of the conditions of composting on mineralization in soil. Therefore, the production of a low CO2 emission amendment requires optimization of feedstocks, co-composting agents and worm species.

Inhibition of existing denitrification enzyme activity by chloramphenicol

USGS Publications Warehouse

Brooks, M.H.; Smith, R.L.; Macalady, D.L.

1992-01-01

Chloramphenicol completely inhibited the activity of existing denitrification enzymes in acetylene-block incubations with (i) sediments from a nitrate-contaminated aquifer and (ii) a continuous culture of denitrifying groundwater bacteria. Control flasks with no antibiotic produced significant amounts of nitrous oxide in the same time period. Amendment with chloramphenicol after nitrous oxide production had begun resulted in a significant decrease in the rate of nitrous oxide production. Chloramphenicol also decreased (>50%) the activity of existing denitrification enzymes in pure cultures of Pseudomonas denitrificans that were harvested during log- phase growth and maintained for 2 weeks in a starvation medium lacking electron donor. Short-term time courses of nitrate consumption and nitrous oxide production in the presence of acetylene with P. denitrificans undergoing carbon starvation were performed under optimal conditions designed to mimic denitrification enzyme activity assays used with soils. Time courses were linear for both chloramphenicol and control flasks, and rate estimates for the two treatments were significantly different at the 95% confidence level. Complete or partial inhibition of existing enzyme activity is not consistent with the current understanding of the mode of action of chloramphenicol or current practice, in which the compound is frequently employed to inhibit de novo protein synthesis during the course of microbial activity assays. The results of this study demonstrate that chloramphenicol amendment can inhibit the activity of existing denitrification enzymes and suggest that caution is needed in the design and interpretation of denitrification activity assays in which chloramphenicol is used to prevent new protein synthesis.

[Effects of biochar application three-years ago on global warming potentials of CH4 and N2O in a rice-wheat rotation system.

PubMed

Wu, Zhen; Dong, Yu Bing; Xiong, Zheng Qin

2018-01-01

To evaluate the long-term effects of biochar amendment on greenhouse gas emissions (GHGs), a field experiment was conducted to examine the effects of 3-year field-aged biochar (B 3 ) and fresh biochar (B 0 ) on global warming potential (GWP) and greenhouse gas intensity (GHGI) of methane (CH 4 ) and nitrous oxide (N 2 O) in a typical rice-wheat rotation system. Four treatments were established as control without nitrogen fertilizer (CK), urea without biochar (N), urea with fresh biochar amended in 2015 (NB 0 ), and urea with 3-year field-aged biochar amended in 2012 (NB 3 ). Results showed that both the NB 0 and NB 3 treatments obviously increased soil pH, soil organic carbon (SOC), total nitrogen (TN) and influenced the potential activity of functional microorganisms related to GHGs compared to the N treatment. Relative to the N treatment, the NB 3 treatment significantly improved crop yield by 14.1% while reduced the CH 4 and N 2 O emissions by 9.0% and 34.0%, respectively. In addition, the NB 0 treatment significantly improved crop yield by 9.3%, while reduced the N 2 O emission by 38.6% though increased the CH 4 emissions by 4.7% relative to the N treatment. Moreover, both the NB 0 and NB 3 treatments could significantly reduce both GWP and GHGI, with NB 3 being more effective in simultaneously mitigating the GHGs emissions and enhancing crop yield. Since field-aged biochar showed obvious effects on GHGs mitigation and carbon sequestration after 3 years, biochar incorporations had long-term effect on GHGs mitigation and crop production in the rice-wheat rotation system.

Quantifying the Contribution of Entire Free-Living Nematode Communities to Carbon Mineralization under Contrasting C and N Availability

PubMed Central

Gebremikael, Mesfin Tsegaye; Steel, Hanne; Bert, Wim; Maenhout, Peter; Sleutel, Steven; De Neve, Stefaan

2015-01-01

To understand the roles of nematodes in organic matter (OM) decomposition, experimental setups should include the entire nematode community, the native soil microflora, and their food sources. Yet, published studies are often based on either simplified experimental setups, using only a few selected species of nematode and their respective prey, despite the multitude of species present in natural soil, or on indirect estimation of the mineralization process using O2 consumption and the fresh weight of nematodes. We set up a six-month incubation experiment to quantify the contribution of the entire free living nematode community to carbon (C) mineralization under realistic conditions. The following treatments were compared with and without grass-clover amendment: defaunated soil reinoculated with the entire free living nematode communities (+Nem) and defaunated soil that was not reinoculated (-Nem). We also included untreated fresh soil as a control (CTR). Nematode abundances and diversity in +Nem was comparable to the CTR showing the success of the reinoculation. No significant differences in C mineralization were found between +Nem and -Nem treatments of the amended and unamended samples at the end of incubation. Other related parameters such as microbial biomass C and enzymatic activities did not show significant differences between +Nem and -Nem treatments in both amended and unamended samples. These findings show that the collective contribution of the entire nematode community to C mineralization is small. Previous reports in literature based on simplified experimental setups and indirect estimations are contrasting with the findings of the current study and further investigations are needed to elucidate the extent and the mechanisms of nematode involvement in C mineralization. PMID:26393517

Total organic carbon and humus fractions in restored soils from limestone quarries in semiarid climate, SE Spain

NASA Astrophysics Data System (ADS)

Luna Ramos, Lourdes; Miralles Mellado, Isabel; Ángel Domene Ruiz, Miguel; Solé Benet, Albert

2016-04-01

Mining activities generate erosion and loss of plant cover and soil organic matter (SOM), especially in arid and semiarid Mediterranean regions. A precondition for ecosystem restoration in such highly disturbed areas is the development of functional soils with sufficient organic matter. But the SOM quality is also important to long-term C stabilization. The resistance to biodegradation of recalcitrant organic matter fractions has been reported to depend on some intrinsic structural factors of humic acid substances and formation of amorphous organo-mineral recalcitrant complexes. In an experimental soil restoration in limestone quarries in the Sierra de Gádor (Almería), SE Spain, several combinations of organic amendments (sewage sludge and compost from domestic organic waste) and mulches (gravel and woodchip) were added in experimental plots using a factorial design. In each plot, 75 native plants (Anthyllis cytisoides, A. terniflora and Macrochloa tenacissima) were planted and five years after the start of the experiment total organic carbon (TOC), physico-chemical soil properties and organic C fractions (particulate organic matter, H3PO4-fulvic fraction, fulvic acids (FA), humic acids (HA) and humin) were analyzed. We observed significant differences between treatments related to the TOC content and the HA/FA ratio. Compost amendments increased the TOC, HA content and HA/FA ratio, even higher than in natural undisturbed soils, indicating an effective clay humus-complex pointing to progressively increasing organic matter quality. Soils with sewage sludge showed the lowest TOC and HA/FA ratio and accumulated a lower HA proportion indicating poorer organic matter quality and comparatively lower resilience than in natural soils and soils amended with compost.

Multivariate regulation of soil CO2 and N2 O pulse emissions from agricultural soils.

PubMed

Liang, Liyin L; Grantz, David A; Jenerette, G Darrel

2016-03-01

Climate and land-use models project increasing occurrence of high temperature and water deficit in both agricultural production systems and terrestrial ecosystems. Episodic soil wetting and subsequent drying may increase the occurrence and magnitude of pulsed biogeochemical activity, affecting carbon (C) and nitrogen (N) cycles and influencing greenhouse gas (GHG) emissions. In this study, we provide the first data to explore the responses of carbon dioxide (CO2 ) and nitrous oxide (N2 O) fluxes to (i) temperature, (ii) soil water content as percent water holding capacity (%WHC), (iii) substrate availability throughout, and (iv) multiple soil drying and rewetting (DW) events. Each of these factors and their interactions exerted effects on GHG emissions over a range of four (CO2 ) and six (N2 O) orders of magnitude. Maximal CO2 and N2 O fluxes were observed in environments combining intermediate %WHC, elevated temperature, and sufficient substrate availability. Amendments of C and N and their interactions significantly affected CO2 and N2 O fluxes and altered their temperature sensitivities (Q10 ) over successive DW cycles. C amendments significantly enhanced CO2 flux, reduced N2 O flux, and decreased the Q10 of both. N amendments had no effect on CO2 flux and increased N2 O flux, while significantly depressing the Q10 for CO2 , and having no effect on the Q10 for N2 O. The dynamics across DW cycles could be attributed to changes in soil microbial communities as the different responses to wetting events in specific group of microorganisms, to the altered substrate availabilities, or to both. The complex interactions among parameters influencing trace gas fluxes should be incorporated into next generation earth system models to improve estimation of GHG emissions. © 2015 John Wiley & Sons Ltd.

Bioprecipitation of Calcium Carbonate Crystals by Bacteria Isolated from Saline Environments Grown in Culture Media Amended with Seawater and Real Brine

PubMed Central

Silva-Castro, G. A.; Uad, I.; Gonzalez-Martinez, A.; Rivadeneyra, A.; Gonzalez-Lopez, J.; Rivadeneyra, M. A.

2015-01-01

The precipitation of calcium carbonate and calcium sulphate by isolated bacteria from seawater and real brine obtained in a desalination plant growth in culture media containing seawater and brine as mineral sources has been studied. However, only bioprecipitation was detected when the bacteria were grown in media with added organic matter. Biomineralization process started rapidly, crystal formation taking place in the beginning a few days after inoculation of media; roughly 90% of total cultivated bacteria showed. Six major colonies with carbonate precipitation capacity dominated bacterial community structure cultivated in heterotrophic platable bacteria medium. Taxonomic identification of these six strains through partial 16S rRNA gene sequences showed their affiliation with Gram-positive Bacillus and Virgibacillus genera. These strains were able to form calcium carbonate minerals, which precipitated as calcite and aragonite crystals and showed bacterial fingerprints or bacteria calcification. Also, carbonic anhydrase activity was observed in three of these isolated bacteria. The results of this research suggest that microbiota isolated from sea water and brine is capable of precipitation of carbonate biominerals, which can occur in situ with mediation of organic matter concentrations. Moreover, calcium carbonate precipitation ability of this microbiota could be of importance in bioremediation of CO2 and calcium in certain environments. PMID:26273646

Bioprecipitation of Calcium Carbonate Crystals by Bacteria Isolated from Saline Environments Grown in Culture Media Amended with Seawater and Real Brine.

PubMed

Silva-Castro, G A; Uad, I; Gonzalez-Martinez, A; Rivadeneyra, A; Gonzalez-Lopez, J; Rivadeneyra, M A

2015-01-01

The precipitation of calcium carbonate and calcium sulphate by isolated bacteria from seawater and real brine obtained in a desalination plant growth in culture media containing seawater and brine as mineral sources has been studied. However, only bioprecipitation was detected when the bacteria were grown in media with added organic matter. Biomineralization process started rapidly, crystal formation taking place in the beginning a few days after inoculation of media; roughly 90% of total cultivated bacteria showed. Six major colonies with carbonate precipitation capacity dominated bacterial community structure cultivated in heterotrophic platable bacteria medium. Taxonomic identification of these six strains through partial 16S rRNA gene sequences showed their affiliation with Gram-positive Bacillus and Virgibacillus genera. These strains were able to form calcium carbonate minerals, which precipitated as calcite and aragonite crystals and showed bacterial fingerprints or bacteria calcification. Also, carbonic anhydrase activity was observed in three of these isolated bacteria. The results of this research suggest that microbiota isolated from sea water and brine is capable of precipitation of carbonate biominerals, which can occur in situ with mediation of organic matter concentrations. Moreover, calcium carbonate precipitation ability of this microbiota could be of importance in bioremediation of CO2 and calcium in certain environments.

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

Knox, Anna Sophia; Paller, Michael H.; Milliken, Charles E.

One challenge to all remedial approaches for contaminated sediments is the continued influx of contaminants from uncontrolled sources following remediation. We investigated the effects of ongoing contamination in mesocosms employing sediments remediated by different types of active and passive caps and in-situ treatment. Our hypothesis was that the sequestering agents used in active caps and in situ treatment will bind elements (arsenic, chromium, cadmium, cobalt, copper, nickel, lead, selenium, and zinc) from ongoing sources thereby reducing their bioavailability and protecting underlying remediated sediments from recontamination. Most element concentrations in surface water remained significantly lower in mesocosms with apatite and mixedmore » amendment caps than in mesocosms with passive caps (sand), uncapped sediment, and spike solution throughout the 2520 hour experiment. Element concentrations were significantly higher in Lumbriculus variegatus from untreated sediment than in Lumbriculus from most active caps. Moreover, Pearson correlations between element concentrations in Lumbriculus and metal concentrations in the top 2.5 cm of sediment or cap measured by diffusive gradient in thin films (DGT) sediment probes were generally strong (as high as 0.98) and significant (p<0.05) for almost all tested elements. Metal concentrations in both Lumbriculus and sediment/cap were lowest in apatite, mixed amendment, and activated carbon treatments. Finally, these findings show that some active caps can protect remediated sediments by reducing the bioavailable pool of metals/metalloids in ongoing sources of contamination.« less

Environmental impact of ongoing sources of metal contamination on remediated sediments

DOE PAGES

Knox, Anna Sophia; Paller, Michael H.; Milliken, Charles E.; ...

2016-04-29

One challenge to all remedial approaches for contaminated sediments is the continued influx of contaminants from uncontrolled sources following remediation. We investigated the effects of ongoing contamination in mesocosms employing sediments remediated by different types of active and passive caps and in-situ treatment. Our hypothesis was that the sequestering agents used in active caps and in situ treatment will bind elements (arsenic, chromium, cadmium, cobalt, copper, nickel, lead, selenium, and zinc) from ongoing sources thereby reducing their bioavailability and protecting underlying remediated sediments from recontamination. Most element concentrations in surface water remained significantly lower in mesocosms with apatite and mixedmore » amendment caps than in mesocosms with passive caps (sand), uncapped sediment, and spike solution throughout the 2520 hour experiment. Element concentrations were significantly higher in Lumbriculus variegatus from untreated sediment than in Lumbriculus from most active caps. Moreover, Pearson correlations between element concentrations in Lumbriculus and metal concentrations in the top 2.5 cm of sediment or cap measured by diffusive gradient in thin films (DGT) sediment probes were generally strong (as high as 0.98) and significant (p<0.05) for almost all tested elements. Metal concentrations in both Lumbriculus and sediment/cap were lowest in apatite, mixed amendment, and activated carbon treatments. Finally, these findings show that some active caps can protect remediated sediments by reducing the bioavailable pool of metals/metalloids in ongoing sources of contamination.« less

Effects of soil amendment on soil characteristics and maize yield in Horqin Sandy Land

NASA Astrophysics Data System (ADS)

Zhou, L.; Liu, J. H.; Zhao, B. P.; Xue, A.; Hao, G. C.

2016-08-01

A 4-year experiment was conducted to investigate the inter-annual effects of sandy soil amendment on maize yield, soil water storage and soil enzymatic activities in sandy soil in Northeast China in 2010 to 2014. We applied the sandy soil amendment in different year, and investigated the different effects of sandy soil amendment in 2014. There were six treatments including: (1) no sandy soil amendment application (CK); (2) one year after applying sandy soil amendment (T1); (3) two years after applying sandy soil amendment(T2); (4) three years after applying sandy soil amendment(T3); (5)four years after applying sandy soil amendment(T4); (6) five years after applying sandy soil amendment (T5). T refers to treatment, and the number refers to the year after application of the sandy soil amendment. Comparing with CK, sandy soil amendments improved the soil water storage, soil urease, invertase, and catalase activity in different growth stages and soil layers, the order of soil water storage in all treatments roughly performed: T3 > T5 > T4 > T2 > T1 > CK. the order of soil urease, invertase, and catalase activity in all treatments roughly performed: T5 > T3 > T4 > T2 > T1 > CK. Soil application of sandy soil amendment significantly (p≤⃒0.05) increased the grain yield and biomass yield by 22.75%-41.42% and 29.92%-45.45% respectively, and maize yield gradually increased with the years go by in the following five years. Sandy soil amendment used in poor sandy soil had a positive effect on soil water storage, soil enzymatic activities and maize yield, after five years applied sandy soil amendment (T5) showed the best effects among all the treatments, and deserves further research.

Chemical immobilization of Pb, Cu, and Cd by phosphate materials and calcium carbonate in contaminated soils.

PubMed

Huang, Guoyong; Su, Xiaojuan; Rizwan, Muhammad Shahid; Zhu, Yifei; Hu, Hongqing

2016-08-01

Soil contamination with toxic metals has increasingly become a global concern over the past few decades. Phosphate and carbonate compounds are good passivation materials for Pb immobilization, while the effect of phosphate and carbonate on the immobilization of multiple heavy metals (Pb, Cu, and Cd) in contaminated soils was seldom investigated. In this study, bone meal (BM), phosphate rock (PR), oxalic acid-activated phosphate rock (APR), super phosphate (SP), and calcium carbonate (CC) were added to the contaminated soils to evaluate the effect of phosphate materials and calcium carbonate on the immobilization of Pb, Cu, and Cd. The results showed that the pH of the treated soils increased 1.3-2.7, except SP which decreased 0.5 at most. Compared to the control treatment, all phosphates and calcium carbonate added to the polluted soils increased the fraction of residual metals, and the application of APR, PR, BM, and CC significantly reduced exchangeable and carbonate-bound fraction metals. PR and APR were the most effective for the immobilization of Pb, Cu, and Cd in the soils among these materials. Moreover, the concentrations of all metals in the toxicity characteristic leaching procedure (TCLP) leachate decreased with increasing amounts of amendments, and the concentrations of Pb in the TCLP leachate for soils treated with PR and APR were below the nonhazardous regulatory limit of 5 mg L(-1) (US Environmental Protection Agency). Based on our results, phosphate rock and oxalic acid-activated phosphate rock are effective in the immobilization of multiple metals by reducing their mobility in the co-contaminated soils.

Bio-oil and bio-char from low temperature pyrolysis of spent grains using activated alumina.

PubMed

Sanna, Aimaro; Li, Sujing; Linforth, Rob; Smart, Katherine A; Andrésen, John M

2011-11-01

The pyrolysis of wheat and barley spent grains resulting from bio-ethanol and beer production respectively was investigated at temperatures between 460 and 540 °C using an activated alumina bed. The results showed that the bio-oil yield and quality depend principally on the applied temperature where pyrolysis at 460 °C leaves a bio-oil with lower nitrogen content in comparison with the original spent grains and low oxygen content. The viscosity profile of the spent grains indicated that activated alumina could promote liquefaction and prevent charring of the structure between 400 and 460 °C. The biochar contains about 10-12% of original carbon and 13-20% of starting nitrogen resulting very attractive as a soil amendment and for carbon sequestration. Overall, value can be added to the spent grains opening a new market in bio-fuel production without the needs of external energy. The bio-oil from spent grains could meet about 9% of the renewable obligation in the UK. Copyright © 2011 Elsevier Ltd. All rights reserved.

Development of a novel multi-functional active membrane capping barrier for the remediation of nitrobenzene-contaminated sediment.

PubMed

Wang, Qing; Li, Yi; Wang, Chao; Wu, Yue; Wang, Peifang

2014-07-15

A novel bio-reactive capping barrier composed of polysulfone/granular activated carbon (PS/GAC) hybrid membranes immobilized with microorganism was developed for the remediation of nitrobenzene in sediments. The SEM observation demonstrated that all the membranes had a dense top layer and a porous sublayer, this structure can block the transfer of nitrobenzene from sediment to the water and enhance nitrobenzene degradation. Adsorption behaviors of nitrobenzene on membranes showed that the membrane impregnated with GAC had better performance than the pure PS membrane. The values of Kads increased from 4.64 (without GAC) to 6.19 (1:2 GAC). 20mg/L nitrobenzene can be completely degraded by Pseudomonas putida immobilized on membranes. The biodegradation rate of activated carbon-filled membrane system was little higher than that of pure PS membrane system. For remediation experiments, only about 21.7, 28.3 and 43.9% of nitrobenzene in the sediment was removed by the end of the experiments for PS/GAC membrane, sand-alone and sand amended with activated carbon capping systems, respectively. While for PS/GAC+microorganisms capping system, more than 70% of nitrobenzene loss was observed. This demonstrated that nitrobenzene can be effectively removed from contaminated sediments by microbial degradation in the bio-reactive capping system. Copyright © 2014 Elsevier B.V. All rights reserved.

A three-year experiment confirms continuous immobilization of cadmium and lead in contaminated paddy field with biochar amendment.

PubMed

Bian, Rongjun; Joseph, Stephen; Cui, Liqiang; Pan, Genxing; Li, Lianqing; Liu, Xiaoyu; Zhang, Afeng; Rutlidge, Helen; Wong, Singwei; Chia, Chee; Marjo, Chris; Gong, Bin; Munroe, Paul; Donne, Scott

2014-05-15

Heavy metal contamination in croplands has been a serious concern because of its high health risk through soil-food chain transfer. A field experiment was conducted in 2010-2012 in a contaminated rice paddy in southern China to determine if bioavailability of soil Cd and Pb could be reduced while grain yield was sustained over 3 years after a single soil amendment of wheat straw biochar. Contaminated biochar particles were separated from the biochar amended soil and microscopically analyzed to help determine where, and how, metals were immobilized with biochar. Biochar soil amendment (BSA) consistently and significantly increased soil pH, total organic carbon and decreased soil extractable Cd and Pb over the 3 year period. While rice plant tissues' Cd content was significantly reduced, depending on biochar application rate, reduction in plant Pb concentration was found only in root tissue. Analysis of the fresh and contaminated biochar particles indicated that Cd and Pb had probably been bonded with the mineral phases of Al, Fe and P on and around and inside the contaminated biochar particle. Immobilization of the Pb and Cd also occurred to cation exchange on the porous carbon structure. Copyright © 2014 Elsevier B.V. All rights reserved.

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.

10 CFR 60.46 - Particular activities requiring license amendment.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 2 2011-01-01 2011-01-01 false Particular activities requiring license amendment. 60.46 Section 60.46 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) DISPOSAL OF HIGH-LEVEL RADIOACTIVE WASTES IN GEOLOGIC REPOSITORIES Licenses License Issuance and Amendment § 60.46 Particular activities...

10 CFR 60.46 - Particular activities requiring license amendment.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 2 2010-01-01 2010-01-01 false Particular activities requiring license amendment. 60.46 Section 60.46 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) DISPOSAL OF HIGH-LEVEL RADIOACTIVE WASTES IN GEOLOGIC REPOSITORIES Licenses License Issuance and Amendment § 60.46 Particular activities...

Nutrient Limitation of Microbial Mediated Decomposition and Arctic Soil Chronology

NASA Astrophysics Data System (ADS)

Melle, C. J.; Darrouzet-Nardi, A.; Wallenstein, M. D.

2012-12-01

Soils of northern permafrost regions currently contain twice as much carbon as the entire Earth's atmosphere. Traditionally, environmental constraints have limited microbial activity resulting in restricted decomposition of soil organic matter in these systems and accumulation of massive amounts of soil organic carbon (SOC), however climate change is reducing the constraints of decomposition in arctic permafrost regions. Carbon cycling in nutrient poor, arctic ecosystems is tightly coupled to other biogeochemical cycles. Several studies have suggested strong nitrogen limitations of primary productivity and potentially warm-season microbial activity in these nutrient deficient soils. Nitrogen is required for microbial extracellular enzyme production which drives the decomposition of soil organic matter (SOM). Nitrogen limited arctic soils may also experience limitation via labile carbon availability despite the SOM rich environment due to low extracellular enzyme production. Few studies have directly addressed nutrient induced microbial limitation in SOC rich arctic tundra soils, and even less is known about the potential for nutrient co-limitation. Additionally, through the process of becoming deglaciated, sites within close proximity to one another may have experienced drastic differences in their effective soil ages due to the varied length of their active histories. Many soil properties and nutrient deficiencies are directly related to soil age, however this chronology has not previously been a focus of research on nutrient limitation of arctic soil microbial activity. Understanding of nutrient limitations, as well as potential co-limitation, on arctic soil microbial activity has important implications for carbon cycling and the ultimate fate of the current arctic SOC reservoir. Analyses of nutrient limitation on soils of a single site are not adequate for fully understanding the controls on soil microbial activity across a vast land mass with large variation in effective soil age. My research is focused on addressing the questions of the extent of microbial N limitation in arctic tundra soils, the potential for co-limitation of labile C despite a high SOC environment, and the dependence, if any, nutrient limitation may have on the effective age of the soil. I have addressed these questions by conducting a laboratory soil incubation of factorial design with treatments of amended glucose, amended ammonium nitrate, and a control consisting of an addition of an equivalent volume of deionized water. Moist acid tundra soils possessing similar soil properties from two arctic sites of close proximity yet with varying deglaciation chronologies were utilized in my study. Soil properties of C-mineralization via respiration, microbial biomass, and nitrogen content in the forms of ammonium, nitrate, and total free amino acids and microbial extra-cellular enzyme production were assayed to determine the microbial response to the experimental treatments. Through the results of this work, I hope to better our understanding of biogeochemical cycling within arctic tundra ecosystems and the response to climate change by contributing to existing knowledge of nutrient limitation on microbial mediated decomposition of SOC in the arctic and how this may differ in soils of varying effective age.

Anaerobic soil disinfestation: Carbon rate effects on tomato plant growth and organic acid production

USDA-ARS?s Scientific Manuscript database

Anaerobic soil disinfestation (ASD) is a non-chemical soil disinfestation technique proposed for the control of soil-borne pathogens, plant parasitic-nematodes, and weeds in different crops. ASD is applied in three steps: 1) Soil amendment with a labile carbon (C) source; 2) Cover the soil with tota...

Biochar: Is it a sustainable solution to dry land agriculture, forest soil reclamation and greenhouse gas mitigation?

USDA-ARS?s Scientific Manuscript database

Biochar is the carbon-rich solid co-product of thermochemical biofuel production, which has been advocated as a soil amendment capable of sequestering carbon while simultaneously improving crop yields and ecosystem sustainability. The recovery of biochar from biofuel production systems and its use a...

78 FR 25701 - Certain Hot-Rolled Carbon Steel Flat Products From India: Notice of Second Amended Final Results...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-02

... DEPARTMENT OF COMMERCE International Trade Administration [C-533-821] Certain Hot-Rolled Carbon... Commerce. SUMMARY: On April 9, 2013, the United States Court of International Trade (CIT) sustained the Department of Commerce's (the Department) January 2013 remand results.\\1\\ The January 2013 remand results...

Biochar as soil amendment to improve soil quality, crop yield, and carbon sequestration

USDA-ARS?s Scientific Manuscript database

Biochar, a by-product of a thermochemical process called pyrolysis, which involves burning of any agricultural and animal waste (biomass) under high temperature and absence of oxygen. It is assumed that since biochar is very high in aromatic carbon, which persists in soil environment for very long ...

Turnover of soil carbon pools following addition of switchgrass-derived biochar to four soils

USDA-ARS?s Scientific Manuscript database

The amendment of soils with biochar may improve plant growth and sequester carbon, especially in marginal soils not suitable for the majority of commodity production. While biochar can persist in soils, it is not clear whether its persistence is affected by soil type. Moreover, we know little of how...

Impact of management practices on water extractable organic carbon and nitrogen from 12-year poultry litter amended soils

USDA-ARS?s Scientific Manuscript database

Water extractable organic carbon (WEOC) and organic N (WEON) are two key parameters of soil water extractable organic matter (WEOM). Proper management of manure application rate in combination with tillage and cropping management could maintain appropriate WEOC and WEON concentrations in soils while...

Particulate matter emissions from biochar-amended soils as a potential tradeoff to the negative emission potential

USDA-ARS?s Scientific Manuscript database

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 impact...

Biochar as a soil amendment: Environmental friend or foe?

EPA Science Inventory

Pyrolysis to produce biofuels and biochar from biomass is not a new idea, but the use of pyrolysis to extract energy from biomass through a process that can be carbon neutral to carbon negative (i.e., reduces atmospheric CO2) is a novel application of an old technology to a curre...

Strontium Incorporation Into Calcite Generated by Bacterial Ureolysis

NASA Astrophysics Data System (ADS)

Fujita, Y.; Ingram, J. A.; Cortez, M. M.; Redden, G. D.; Smith, R. W.

2002-12-01

Strontium incorporation into calcite generated by bacterial ureolytic activity was investigated as part of a larger effort to evaluate the use of in situ urea hydrolysis for accelerating co-precipitation of trace metals and radionuclides in contaminated aquifers. 90Sr, a uranium fission product with a half-life of 29 years, is a significant subsurface contaminant at several Department of Energy facilities and could be immobilized using this remediation strategy. Experiments were conducted in a medium designed to simulate the groundwater of the Snake River Plain Aquifer in eastern Idaho, amended with strontium. Initially the solution was undersaturated with respect to calcite. As a model ureolytic organism, we used Bacillus pasteurii, a well-characterized bacterium known for high urease activity and previously shown to induce calcite precipitation in urea-amended medium. To gain information on the effect of the bacterial surfaces, we also looked at precipitation in the presence of a bacterial species that did not hydrolyze urea, as well as in the absence of bacteria. In the absence of bacterial ureolysis, carbonate precipitation was induced by addition of ammonium carbonate. All products were identified as calcite by X-ray diffraction. Strontium uptake was observed in all cases, but was greatest in the system including bacterial ureolysis. Sputter depth element profiling by time-of-flight secondary ion mass spectrometry (TOF-SIMS) confirmed this finding, showing highest Sr:Ca ratios in the bacterially generated calcite throughout the depth (~350 nm) investigated. Environmental Scanning Electron Microscopy (ESEM) of the solids revealed regular crystals containing the outlines of embedded or entombed bacterial cells, suggesting that calcite precipitated directly on the cell surfaces when present. Analysis by X-ray Absorption Near Edge Spectroscopy (XANES) indicated that in both the biotically and abiotically generated calcites the Sr was incorporated into the calcite lattice structure, rather than forming strontium carbonate. These findings are encouraging with respect to long term containment and stabilization of strontium by the proposed remediation strategy.

32 CFR 767.8 - Requests for amendments or extensions of active permits.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 32 National Defense 5 2013-07-01 2013-07-01 false Requests for amendments or extensions of active permits. 767.8 Section 767.8 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY... extensions of active permits. (a) Requests for amendments to active permits (e.g., a change in study design...

32 CFR 767.8 - Requests for amendments or extensions of active permits.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 32 National Defense 5 2012-07-01 2012-07-01 false Requests for amendments or extensions of active permits. 767.8 Section 767.8 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY... extensions of active permits. (a) Requests for amendments to active permits (e.g., a change in study design...

32 CFR 767.8 - Requests for amendments or extensions of active permits.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 32 National Defense 5 2014-07-01 2014-07-01 false Requests for amendments or extensions of active permits. 767.8 Section 767.8 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY... extensions of active permits. (a) Requests for amendments to active permits (e.g., a change in study design...

32 CFR 767.8 - Requests for amendments or extensions of active permits.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 32 National Defense 5 2011-07-01 2011-07-01 false Requests for amendments or extensions of active permits. 767.8 Section 767.8 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY... extensions of active permits. (a) Requests for amendments to active permits (e.g., a change in study design...

Technical feasibility and carbon footprint of biochar co-production with tomato plant residue.

PubMed

Llorach-Massana, Pere; Lopez-Capel, Elisa; Peña, Javier; Rieradevall, Joan; Montero, Juan Ignacio; Puy, Neus

2017-09-01

World tomato production is in the increase, generating large amounts of organic agricultural waste, which are currently incinerated or composted, releasing CO 2 into the atmosphere. Organic waste is not only produced from conventional but also urban agricultural practices due recently gained popularity. An alternative to current waste management practices and carbon sequestration opportunity is the production of biochar (thermally converted biomass) from tomato plant residues and use as a soil amendment. To address the real contribution of biochar for greenhouse gas mitigation, it is necessary to assess the whole life cycle from the production of the tomato biomass feedstock to the actual distribution and utilisation of the biochar produced in a regional context. This study is the first step to determine the technical and environmental potential of producing biochar from tomato plant (Solanum lycopersicum arawak variety) waste biomass and utilisation as a soil amendment. The study includes the characterisation of tomato plant residue as biochar feedstock (cellulose, hemicellulose, lignin and metal content); feedstock thermal stability; and the carbon footprint of biochar production under urban agriculture at pilot and small-scale plant, and conventional agriculture at large-scale plant. Tomato plant residue is a potentially suitable biochar feedstock under current European Certification based on its lignin content (19.7%) and low metal concentration. Biomass conversion yields of over 40%, 50% carbon stabilization and low pyrolysis temperature conditions (350-400°C) would be required for biochar production to sequester carbon under urban pilot scale conditions; while large-scale biochar production from conventional agricultural practices have not the potential to sequestrate carbon because its logistics, which could be improved. Therefore, the diversion of tomato biomass waste residue from incineration or composting to biochar production for use as a soil amendment would environmentally be beneficial, but only if high biochar yields could be produced. Copyright © 2017 Elsevier Ltd. All rights reserved.

Potential For Denitrification near Reclaimed Water Application Sites in Orange County, Florida, 2009

USGS Publications Warehouse

Byrne, Michael J.; Smith, Richard L.; Repert, Deborah A.

2012-01-01

The potential for denitrification was tested in water samples from four Upper Floridan aquifer wells near a reclaimed water application site, in west Orange County Florida, and two adjacent springs. Results of the study indicate that denitrifying bacteria are present in the groundwater and spring water samples, and that these bacteria can readily denitrify the waters when suitable geochemical conditions exist. The acetylene block technique was used to assess nitrous oxide in the samples that was produced by denitrification. The laboratory incubation experiment consisted of four different treatments to each of the six samples: (1) ambient water (no added nitrate or glucose), (2) ambient water amended with 1.4 milligrams per liter (mg/L) nitrate as nitrogen (N), (3) ambient water amended with 5.0 mg/L nitrate as N, and (4) ambient water amended with 5.0 mg/L nitrate as N and 10 mg/L glucose as C6H12O6. A companion set of incubations using treatment 2 tracked changes in nitrate and nitrite concentration with time. The rate of denitrification in treatment 2 ranged from 0.059 to 0.124 milligram per liter per day nitrogen [(mg/L)/d N] and in treatment 3 ranged from 0.071 to 0.226 (mg/L)/d N. At all of the sampling sites, treatment 4 yielded denitrification rates at least an order of magnitude greater than those measured for the other treatments; rates ranged from 2.3 to 4.4 (mg/L)/d N. The electron donor supply, dissolved organic carbon, in the groundwater and springwater is sufficient to remove at least 1.1-1.4 mg/L nitrate as N in 20 to 30 days, as indicated by nitrous oxide production rates under ambient conditions (treatment 1). The even higher nitrate removal observed with addition of supplemental carbon in treatment 4 suggests that carbon is a limiting nutrient in this reaction. Denitrifying activity might explain the low ambient nitrate concentrations in the Upper Floridan aquifer in this area.

Preliminary Testing of Mycoleptodiscus terrestris Formulations

DTIC Science & Technology

2009-03-01

Colletotrichum truncatum (Schw.) Andrus and Moore for management of hemp sesbania, Jackson (1997) found that carbon concentration in the medium...dry overnight. When the moisture content was between 5 and 10 percent, the granules were vacuum packed into plastic bags and stored at 4º C until...amended with ammonium chloride (0.5 g/L) and Esmigran (1.7 g/L). Four plastic cups (0.95 L) filled three-fourths with amended lake sediment were planted

Mitigating methane emission from paddy soil with rice-straw biochar amendment under projected climate change

PubMed Central

Han, Xingguo; Sun, Xue; Wang, Cheng; Wu, Mengxiong; Dong, Da; Zhong, Ting; Thies, Janice E.; Wu, Weixiang

2016-01-01

Elevated global temperatures and increased concentrations of carbon dioxide (CO2) in the atmosphere associated with climate change will exert profound effects on rice cropping systems, particularly on their greenhouse gas emitting potential. Incorporating biochar into paddy soil has been shown previously to reduce methane (CH4) emission from paddy rice under ambient temperature and CO2. We examined the ability of rice straw-derived biochar to reduce CH4 emission from paddy soil under elevated temperature and CO2 concentrations expected in the future. Adding biochar to paddy soil reduced CH4 emission under ambient conditions and significantly reduced emissions by 39.5% (ranging from 185.4 mg kg−1 dry weight soil, dws season−1 to 112.2 mg kg−1 dws season−1) under simultaneously elevated temperature and CO2. Reduced CH4 release was mainly attributable to the decreased activity of methanogens along with the increased CH4 oxidation activity and pmoA gene abundance of methanotrophs. Our findings highlight the valuable services of biochar amendment for CH4 control from paddy soil in a future that will be shaped by climate change. PMID:27090814

Delivery and Establishing Slow Release Carbon Source to the Hanford Vadose Zone Using Colloidal Silica Suspension Injection and Subsequent Gelation - Laboratory Study

NASA Astrophysics Data System (ADS)

Zhong, L.; Lee, M. H.; Lee, B.; Yang, S.

2016-12-01

Delivery of nutrient to and establish a slow release carbon source in the vadose zone and capillary fringe zone is essential for setting up of a long-lasting bioremediation of contaminations in those zones. Conventional solution-based injection and infiltration approaches are facing challenges to achieve the delivery and remedial goals. Aqueous silica suspensions undergo a delayed gelation process under favorite geochemical conditions. The delay in gelation provides a time window for the injection of the suspension into the subsurface; and the gelation of the amendment-silica suspension enables the amendment-laden gel to stay in the target zone and slowly release the constituents for contaminant remediation. This approach can potentially be applied to deliver bio-nutrients to the vadose zone and capillary fringe zone for enhanced bioremediation and achieve remedial goals. This research was conducted to demonstrate delayed gelation of colloidal silica suspensions when carbon sources were added and to prove the gelation occurs in sediments under vadose conditions. Sodium lactate, vegetable oil, ethanol, and molasses were tested as the examples of carbon source (or nutrient) amendments. The rheological properties of the silica suspensions during the gelation were characterized. The influence of silica, salinity, nutrient concentrations, and the type of nutrients was studied. The kinetics of nutrient release from silica-nutrient gel was quantified using molasses as the example, and the influence of suspension gelation time was evaluated. The injection behavior of the suspensions was investigated by monitoring their viscosity changes and the injection pressures when the suspensions were delivered into sediment columns.

Relationship between organic matter humification and bioavailability of sludge-borne copper and cadmium during long-term sludge amendment to soil.

PubMed

Liu, Hongtao

2016-10-01

Recycling of sludge as soil amendment poses certain risk of heavy metals contamination. This study investigated the relationship between organic matter in composted sludge and its heavy metals bioavailability over 7years. Periodic monitoring indicated a gradual increase in organic matter degradation, accompanied by changing degrees of polymerization, i.e., ratio of humic acid (HA)/fulvic acid (FA) coupled with incremental exchangeable fraction of copper (Cu) in sludge, with a growing rate of 74.7%, rather than that in soil. However, cadmium (Cd) in composted sludge exhibited an independent manner. Linear-regression analysis revealed that the total proportion of the Cu active fraction (exchangeable plus carbonate bound) was better correlated with the degree of polymerization (DP) and humification ratio (HR) than the degradation ratio of organic matter. Overall, amount of uptaken Cu was more dependent on the humification degree of organic matter, especially the proportion of HA in humus. Copyright © 2016 Elsevier B.V. All rights reserved.

Superfund Record of Decision (EPA Region 4): Aberdeen Pesticide Dumps, Moore County, Aberdeen, NC. (First remedial action), (Amendment), September 1991

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

Not Available

1991-09-30

The Aberdeen Pesticide Dumps site consists of a plant area and four disposal areas in Aberdeen, Moore County, North Carolina. The five areas are Farm Chemicals, Twin Sites, Fairway Six, McIver Dump, and Route 211. Ground water is the main source of drinking water for local residents. After investigations by EPA's Emergency Response Section in 1985 and 1986, several removal actions were conducted, including removing surface contaminants, drums, and soil in several areas. The ROD concurrently addresses surface and subsurface soil contamination. The amended remedial action for this site includes conducting a treatability study using thermal desorption; excavating and treatingmore » a total of 123,933 cubic yards of soil from all five areas including previously excavated soil from the Fairway Six and McIver Dump areas using an onsite thermal desorption process that includes an activated carbon adsorption to treat off-gases, followed by offsite incineration of residual organics.« less

Sequestration of Soil Carbon as Secondary Carbonates (Invited)

NASA Astrophysics Data System (ADS)

Lal, R.

2013-12-01

Rattan Lal Carbon Management and Sequestration Center The Ohio State University Columbus, OH 43210 USA Abstract World soils, the major carbon (C) reservoir among the terrestrial pools, contain soil organic C (SOC) and soil inorganic C (SIC). The SIC pool is predominant in soils of arid and semi-arid regions. These regions cover a land area of about 4.9x109 ha. The SIC pool in soils containing calcic and petrocalcic horizons is estimated at about 695-748 Pg (Pg = 1015 g = 1 gigaton) to 1-m depth. There are two types of carbonates. Lithogenic or primary carbonates are formed from weathering of carbonaceous rocks. Pedogenic or secondary carbonates are formed by dissolution of CO2 in the soil air to form carbonic acid and precipitation as carbonates of Ca+2 or Mg+2. It is the availability of Ca+2 or Mg+2 from outside the ecosystem that is essential to sequester atmospheric CO2. Common among outside sources of Ca+2 or Mg+2 are irrigation water, aerial deposition, sea breeze, fertilizers, manure and other amendments. The decomposition of SOC and root respiration may increase the partial pressure of CO2 in the soil air and lead to the formation of HCO_3^- upon dissolution in H20. Precipitation of secondary carbonates may result from decreased partial pressure of CO2 in the sub-soil, increased concentration of Ca+2, Mg+2 and HCO_3^- in soil solution, and decreased soil moisture content by evapotranspiration. Transport of bicarbonates in irrigated soils and subsequent precipitation above the ground water (calcrete), activity of termites and other soil fauna, and management of urban soils lead to formation of secondary carbonates. On a geologic time scale, weathering of silicate minerals and transport of the by-products into the ocean is a geological process of sequestration of atmospheric CO2. Factors affecting formation of secondary carbonates include land use, and soil and crop management including application of biosolids, irrigation and the quality of irrigation water, activity and species diversity of soil biota, management of soil fertility and application of Ca-bearing amendments (e.g., lime, single and triple super phosphate, manure), and adoption of conservation-effective measures which trap alluvial and aeolian sediments. Even the low rate of formation of secondary carbonates at 2-5 kg C/ha/yr has implications to aggregation, and microbiological and regolith properties. The isotropic composition of secondary carbonates is a useful tool for reconstructing paleoecological conditions. Researchable priorities include: 1) assessment of the depth distribution of CO2 concentration in soil air and its spatial and temporal variation in relation to tillage systems, crop residue management, fertilizer and manuring, irrigation, cover cropping, agroforestry, etc., 2) understanding the effects of micro and meso-climate (e.g., rainfall, evapotranspiration, air and soil temperatures) on CO2 concentration in soil air, 3) determination of the relation between soil profile characteristics (texture, structure, horizonation, hydrology) and secondary carbonates at present and under paleoecological conditions, 4) establishing the relationship between SOC and SIC pools, 5) determination of the impacts of deforestation, biomass burning, wild fires, drought, inundation, etc., on SIC dynamics, and 6) evaluating the effects of secondary carbonates on soil aggregation and water retention.

Effects of biochar amendments on soil microbial biomass and activity.

PubMed

Zhang, H; Voroney, R P; Price, G W

2014-11-01

Environmental benefits reported in the literature of using biochar as a soil amendment are generally increased microbial activity and reduced greenhouse gas (GHG) emissions. This study determined the effects of amendment with biomass feedstocks (spent coffee grounds, wood pellets, and horse bedding compost) and that of biochars (700°C) produced from these feedstocks on soil microbial biomass (C and N) and activity. Soils were amended with these substrates at 0.75% by weight and incubated for up to 175 d under laboratory conditions. Biochar residual effects on soil microbial activity were also studied by amending these soils with either ammonium nitrate (NHNO, 35 mg N kg) or with glucose (864 mg C kg) plus NHNO. Soil microbial biomass C and N, net N mineralization, and CO, NO, and CH emissions were measured. Amendment with biomass feedstocks significantly increased soil microbial biomass and activity, whereas amendment with the biochars had no significant effect. Also, biochar amendment had no significant effect on either net N mineralization or NO and CH emissions from soil. These results indicate that production of biochars at this high temperature eliminated potential substrates. Microbial biomass C in biochar-amended and unamended soils was not significantly different following additions of NHNO or glucose plus NHNO, suggesting that microbial access to otherwise labile C and N was not affected. This study shows that biochars produced at 700°C, regardless of feedstock source, do not enhance soil microbial biomass or activity. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Effects of soil amendment with different carbon sources and other factors on the bioremediation of an aged PAH-contaminated soil.

PubMed

Teng, Ying; Luo, Yongming; Ping, Lifeng; Zou, Dexun; Li, Zhengao; Christie, Peter

2010-04-01

Carbon supplementation, soil moisture and soil aeration are believed to enhance in situ bioremediation of PAH-contaminated soils by stimulating the growth of indigenous microorganisms. However, the effects of added carbon and nitrogen together with soil moisture and soil aeration on the dissipation of PAHs and on associated microbial counts have yet to be fully assessed. In this study the effects on bioremediation of carbon source, carbon-to-nitrogen ratio, soil moisture and aeration on an aged PAH-contaminated agricultural soil were studied in microcosms over a 90-day period. Additions of starch, glucose and sodium succinate increased soil bacterial and fungal counts and accelerated the dissipation of phenanthrene and benzo(a)pyrene in soil. Decreases in phenanthrene and benzo(a)pyrene concentrations were effective in soil supplemented with glucose and sodium succinate (both 0.2 g C kg(-1) dry soil) and starch (1.0 g C kg(-1) dry soil). The bioremediation effect at a C/N ratio of 10:1 was significantly higher (P < 0.05) than at a C/N of either 25:1 or 40:1. Soil microbial counts and PAH dissipation were lower in the submerged soil but soil aeration increased bacterial and fungal counts, enhanced indigenous microbial metabolic activities, and accelerated the natural degradation of phenanthrene and benzo(a)pyrene. The results suggest that optimizing carbon source, C/N ratio, soil moisture and aeration conditions may be a feasible remediation strategy in certain PAH contaminated soils with large active microbial populations.

Remediation of organochlorine pesticides contaminated lake sediment using activated carbon and carbon nanotubes.

PubMed

Hua, Shan; Gong, Ji-Lai; Zeng, Guang-Ming; Yao, Fu-Bing; Guo, Min; Ou, Xiao-Ming

2017-06-01

Organochlorine pesticides (OCPs) in sediment were a potential damage for humans and ecosystems. The aim of this work was to determine the effectiveness of carbon materials remedy hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethanes (DDTs) in sediment. Two different carbon materials including activated carbon (AC) and multi-walled carbon nanotubes (MWCNTs) were used in the present research. Sediment treated with 2 wt% AC and MWCNTs after 150 d contact showed 97%, and 75% reduction for HCH, and 93% and 59% decrease for DDTs in aqueous equilibrium concentration, respectively. Similarly, the reduction efficiencies of DDT and HCH uptake by semipermeable membrane devices (SPMDs) treated with AC (MWCNTs) were 97% (75%) and 92% (63%), respectively under the identical conditions. Furthermore, for 2 wt% AC (MWCNTs) system, a reduction of XAD beads uptake up to 87% (52%) and 73% (67%) was obtained in HCH and DDT flux to overlying water in quiescent system. Adding MWCNTs to contaminated sediment did not significantly decrease aqueous equilibrium concentration and DDTs and HCH availability in SPMDs compared to AC treatment. A series of results indicated that AC had significantly higher remediation efficiency towards HCH and DDTs in sediment than MWCNTs. Additionally, the removal efficiencies of two organic pollutants improved with increasing material doses and contact times. The greater effectiveness of AC was attributed to its greater specific surface area, which was favorable for binding contaminants. These results highlighted the potential for using AC as in-situ sorbent amendments for sediment remediation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Analyzing the impacts of three types of biochar on soil carbon fractions and physiochemical properties in a corn-soybean rotation

USDA-ARS?s Scientific Manuscript database

Biochar is a soil amendment produced from incomplete pyrolysis of organic materials in the absence of oxygen. In most previous studies, the impacts of biochar on soil physical properties and organic carbon was investigated under controlled conditions such as laboratory or greenhouse environments. Th...

Potential for Carbon Sequestration in European Soils: Preliminary Estimates for Five Scenarios Using Results from Long-Term Experiments

DOE Data Explorer

Smith, P. [University of Aberdeen, Aberdeen, UK; Powlson, D. [University of Aberdeen, Aberdeen, UK; Glendining, M. [University of Aberdeen, Aberdeen, UK; Smith, J. [University of Aberdeen, Aberdeen, UK

2003-01-01

One of the main options for carbon mitigation identified by the IPCC is the sequestration of carbon in soils. In this paper we use statistical relationships derived from European long-term experiments to explore the potential for carbon sequestration in soils in the European Union. We examine five scenarios, namely (a) the amendment of arable soils with animal manure, (b) the amendment of arable soils with sewage sludge, (c) the incorporation of cereal straw into the soils in which it was grown, (d) the afforestation of surplus arable land through natural woodland regeneration, and (e) extensification of agriculture through ley-arable farming. Our calculations suggest only limited potential to increase soil carbon stocks over the next century by addition of animal manure, sewage sludge or straw (<15 Tg C y^–1), but greater potential through extensification of agriculture (~40 Tg C y^–1) or through the afforestation of surplus arable land (~50 Tg C y^–1). We estimate that extensification could increase the total soil carbon stock of the European Union by 17%. Afforestation of 30% of present arable land would increase soil carbon stocks by about 8% over a century and would substitute up to 30 Tg C y^–1 of fossil fuel carbon if the wood were used as biofuel. However, even the afforestation scenario, with the greatest potential for carbon mitigation, can sequester only 0.8% of annual global anthropogenic CO2-carbon. Our figures suggest that, although efforts in temperate agriculture can contribute to global carbon mitigation, the potential is small compared to that available through reducing anthropogenic CO2 emissions by halting tropical and sub-tropical deforestation or by reducing fossil fuel burning.

Organic and inorganic amendment application on mercury-polluted soils: effects on soil chemical and biochemical properties.

PubMed

García-Sánchez, Mercedes; Klouza, Martin; Holečková, Zlata; Tlustoš, Pavel; Száková, Jiřina

2016-07-01

On the basis of a previous study performed in our laboratory, the use of organic and inorganic amendments can significantly modify the Hg mobility in soil. We have compared the effectiveness of organic and inorganic amendments such as digestate and fly ash, respectively, reducing the Hg mobility in Chernozem and Luvisol soils differing in their physicochemical properties. Hence, the aim of this work was to compare the impact of digestate and fly ash application on the chemical and biochemical parameters in these two mercury-contaminated soils in a model batch experiment. Chernozem and Luvisol soils were artificially contaminated with Hg and then incubated under controlled conditions for 21 days. Digestate and fly ash were applied to both soils in a dose of 10 and 1.5 %, respectively, and soil samples were collected after 1, 7, 14, and 21 days of incubation. The presence of Hg in both soils negatively affected to processes such as nitrification, provoked a decline in the soil microbial biomass C (soil microbial biomass C (MBC)), and the microbial activities (arylsulfatase, and β-glucosaminidase) in both soils. Meanwhile, the digestate addition to Chernozem and Luvisol soils contaminated with Hg improved the soil chemical properties (pH, dissolved organic carbon (DOC), N (Ntot), inorganic-N forms (N-NH4 (+) and N-NO3 (-))), as consequence of high content in C and N contained in digestate. Likewise, the soil MBC and soil microbial activities (dehydrogenase, arylsulfatase, and β-glucosaminidase) were greatly enhanced by the digestate application in both soils. In contrast, fly ash application did not have a remarkable positive effect when compared to digestate in Chernozem and Luvisol soil contaminated with mercury. These results may indicate that the use of organic amendments such as digestate considerably improved the soil health in Chernozem and Luvisol compared with fly ash, alleviating the detrimental impact of Hg. Probably, the chemical properties present in digestate may determine its use as a suitable amendment for the assisted-natural attenuation of mercury-polluted soils.

Mixing of water masses caused by a drifting iceberg affects bacterial activity, community composition and substrate utilization capability in the Southern Ocean.

PubMed

Dinasquet, Julie; Richert, Inga; Logares, Ramiro; Yager, Patricia; Bertilsson, Stefan; Riemann, Lasse

2017-06-01

The number of icebergs produced from ice-shelf disintegration has increased over the past decade in Antarctica. These drifting icebergs mix the water column, influence stratification and nutrient condition, and can affect local productivity and food web composition. Data on whether icebergs affect bacterioplankton function and composition are scarce, however. We assessed the influence of iceberg drift on bacterial community composition and on their ability to exploit carbon substrates during summer in the coastal Southern Ocean. An elevated bacterial production and a different community composition were observed in iceberg-influenced waters relative to the undisturbed water column nearby. These major differences were confirmed in short-term incubations with bromodeoxyuridine followed by CARD-FISH. Furthermore, one-week bottle incubations amended with inorganic nutrients and carbon substrates (a mix of substrates, glutamine, N-acetylglucosamine, or pyruvate) revealed contrasting capacity of bacterioplankton to utilize specific carbon substrates in the iceberg-influenced waters compared with the undisturbed site. Our study demonstrates that the hydrographical perturbations introduced by a drifting iceberg can affect activity, composition, and substrate utilization capability of marine bacterioplankton. Consequently, in a context of global warming, increased frequency of drifting icebergs in polar regions holds the potential to affect carbon and nutrient biogeochemistry at local and possibly regional scales. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

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.

Efficiency of sewage sludge biochar in improving urban soil properties and promoting grass growth.

PubMed

Yue, Yan; Cui, Liu; Lin, Qimei; Li, Guitong; Zhao, Xiaorong

2017-04-01

It is meaningful to quickly improve poor urban soil fertility in order to establish the green land vegetation. In this study, a series rates (0%, 1%, 5%, 10%, 20% and 50%, in mass ratio) of biochar derived from municipal sewage sludge was applied into an urban soil and then turf grass was grown in pots. The results showed that biochar amendment induced significant increases in soil total nitrogen, organic carbon, black carbon, and available phosphorus and potassium by more than 1.5, 1.9, 4.5, 5.6 and 0.4 times, respectively. Turf grass dry matter increased proportionally with increasing amount of added biochar (by an average of 74%), due to the improvement in plant mineral nutrition. Biochar amendment largely increased the total amounts of soil heavy metals. However, 43-97% of the heavy metals in the amended soil were concentrated in the residual fraction with low bioavailability. So the accumulation of heavy metals in turf grass aboveground biomass was highly reduced by the addition of biochar. These results indicated that sewage sludge biochar could be recommended in the poor urban raw soil as a soil conditioner at a rate of 50%. However, the environmental risk of heavy metal accumulation in soil amended with sewage sludge biochar should be carefully considered. Copyright © 2017 Elsevier Ltd. All rights reserved.

In situ stabilization of cadmium-, lead-, and zinc-contaminated soil using various amendments.

PubMed

Lee, Sang-Hwan; Lee, Jin-Soo; Choi, Youn Jeong; Kim, Jeong-Gyu

2009-11-01

Chemical stabilization is an in situ remediation method that uses inexpensive amendments to reduce contaminant availability in polluted soil. We tested the effects of several amendments (limestone, red-mud, and furnace slag) on the extractability of heavy metals, microbial activities, phytoavailability of soil metals (assessed using lettuce, Lactuca sativa L.), and availability of heavy metals in ingested soil to the human gastrointestinal system (assessed using the physiologically based extraction test). The application of soil amendments significantly decreased the amount of soluble and extractable heavy metals in the soil (p<0.05). The decreased extractable metal content of soil was accompanied by increased microbial activity and decreased plant uptake of heavy metals. Soil microbial activities (soil respiration, urease, and dehydrogenase activity) significantly increased in limestone and red-mud-amended soils. Red-mud was the most effective treatment in decreasing heavy-metal concentrations in lettuce. Compared to non-amended control soil, lettuce uptake of Cd, Pb, and Zn was reduced 86%, 58%, and 73%, respectively, by the addition of red-mud.

Greenhouse gas emission from soil amended with biochar made from hydrothermally carbonizing swine solids

USDA-ARS?s Scientific Manuscript database

Biochar made from hydrothermally carbonizing swine solids was mixed with a 50/50 mixture of Norfolk Ap and E horizon at a rate of 20 g/kg. During the incubation period of 54 days, greenhouse gas (CO2 and N2O) emission fluxes were calculated by nonlinearly regressing time-series headspace gas concent...

Belowground carbon dynamics in lohlolly pine (Pinus taeda) immediately following diammonium phosphate fertilization

Treesearch

Christopher M. Gough; John R. Seiler

2004-01-01

Forest soils store an immense quantity of labile carbon (C) and a may be large potential sink for atmospheric C. Forest management practices such as fertilization may enhance overall C storage in soils, yet changes in physiological processes following nutrient amendments have not been widely investigated. We intensively monitored below-ground C dynamics for nearly 200...

Short-term effects of natural and NH4+-enriched chabazite zeolitite amendments to soil microbial biomass

NASA Astrophysics Data System (ADS)

Ferretti, Giacomo; Keiblinger, Katharina Maria; Di Giuseppe, Dario; Faccini, Barbara; Colombani, Nicolò; Zechmeister-Boltenstern, Sophie; Coltorti, Massimo; Mastrocicco, Micòl

2017-04-01

Natural zeolite-bearing rocks (zeolitites) are known to be a suitable material for agricultural purposes by improving soil physicochemical properties and nitrogen use efficiency (NUE). However, little is known about their effects on soil microbial biomass. Aim of this work is to evaluate short-term effects of different chabazite-zeolitite amendments on soil microbial biomass (and activity). To this purpose a silty-clay agricultural soil was amended in three different ways, by the addition of 5 and 15 wt% of natural chabazite zeolitites (NZ) and 10 wt% of NH4+-enriched chabazite zeolitites (CZ). Soil pH, water content, dissolved organic carbon (C), total dissolved N, NH4+, NO3-, NO2-, microbial biomass C and N and ergosterol were periodically measured over a time course of 16 days in a laboratory incubation experiment. In order to verify the immobilization of N derived from CZ into microbial biomass, the δ15N signature of microorganisms was evaluated by the Extraction-Fumigation-Extraction method followed by EA-IRMS analysis. This latter investigation was possible because zeolitites were enriched with NH4+ derived from pig-slurry, which have a very high 15N natural abundance that allow to trace microbial incorporation. Soil amended with 5 wt% of NZ showed increased ergosterol content as well as microbial C/N ratio starting from day 9 of incubation, suggesting that fungal biomass was probably favored, although the same behavior was not found in the soil amended with 15 wt% of the same material. On the other hand, the NH4+-enriched CZ showed strong interactions with soil microbial biomass N. Isotopic measurements supported microbial assimilation of the N introduced with CZ since the second day of incubation. The high dissolved organic C and microbial biomass N suggested an increase of mineralization and immobilization processes. In addition, in CZ amended soil, microbial biomass N was related to NO3- production over time and inversely related to NH4+, suggesting high nitrification processes especially from day 7 of incubation. Low microbial C/N ratio support bacterial prevalence in the soil amended with CZ for N-assimilation and ammonia oxidation. This confirm that CZ is an efficient soil amendment providing an immediately available N pool to soil microbial biomass.

Soils as a Solution: The Potential of Rangelands to Contribute to Climate Change Mitigation

NASA Astrophysics Data System (ADS)

Silver, W. L.; Ryals, R.; DeLonge, M. S.; Owen, J. J.

2015-12-01

The majority of soil-related climate change research has focused on describing the problem - estimating rates of carbon (C) losses and greenhouse gas (GHG) emissions from natural and managed ecosystems. More research is needed to explore potential solutions to climate change through mitigation and adaptation. Here we report on an integrated set of studies aimed at critically evaluating the biogeochemical potential of rangeland soils to help mitigate climate change, while improving the sustainability and productivity of food production systems. We explored direct effects through enhanced net primary production (NPP) and soil C sequestration, and indirect effects through diversion of high emitting sources to lower emitting organic matter dynamics. We used a combination of long- and short-term field experiments, modeling, laboratory assays, life cycle assessment (LCA), and meta-analyses in consultation with a diverse group of stakeholders from both the private and public sectors. We found that organic matter amendments held particularly strong potential. Compost amendments increased soil C storage by 0.5-1.0 Mg C ha-1 y-1 in surface soils over 5 y, and increased NPP and water holding capacity. We measured 1.0 Mg of new C ha-1 y-1 over 3 y. Long-term amendment of cattle manure increased surface soil C by 19.0±7.3 Mg C ha-1 relative to unmanured fields. However, field and modeling experiments suggested that manure amendments lead to large nitrous oxide emissions that eventually eliminated CO2e benefits, whereas compost amendments continued to benefit climate for decades longer. An LCA identified a broader range of climate impacts. When scaled to an area of 25% of California's rangelands, new C sequestered following compost amendments (21 million Mg CO2e) exceeded emissions from cattle (15 million Mg CO2e); diverting organics from waste streams to amendments led to additional GHG savings. In collaboration with our partners, our research contributed to the development of a protocol for compost amendments, which is being used by stakeholders in C markets and by government agencies in climate action planning. In summary, we hope that our research and related activities will serve as a "call to arms" to the scientific community by highlighting a new and much needed arena for rigorous scientific research.

Leaching of Cu, Cd, Pb, and phosphorus and their availability in the phosphate-amended contaminated soils under simulated acid rain.

PubMed

Cui, Hongbiao; Zhang, Shiwen; Li, Ruyan; Yi, Qitao; Zheng, Xuebo; Hu, Youbiao; Zhou, Jing

2017-09-01

Phosphate amendments have been used to immobilize heavy metal-contaminated soils. However, phosphate amendments contain large amounts of phosphorus, which could leach out to potentially contaminate groundwater and surface water. A laboratory column leaching experiment was designed to study the effects of simulated acid rain (SAR) on the potential release of copper (Cu), lead (Pb), cadmium (Cd), and phosphorus (P), and their availability after immobilizing with hydroxyapatite (HAP) and potassium dihydrogen phosphate (PDP). The application of HAP and PDP enhanced the leachate electrical conductivity, total organic carbon, and pH. Higher P was found in the PDP- (>4.29 mg L -1 ) and HAP-treated (>1.69 mg L -1 ) columns than that in untreated (<0.2 mg L -1 ) columns, and they were both over the class V limit (0.4 mg L -1 ) mandated by the Chinese National Quality Standards for Surface Waters (GB 3838-2002). PDP application decreased the leachate Cu, Pb, and Cd effectively; however, HAP addition increased leachate Cu and Pb. HAP and PDP applications decreased the soil CaCl 2 -extractable and exchangeable fraction of Cu, Pb, and Cd, and increased resin P. However, eluviations transformed the heavy metals from inactive to active fractions and reduced soil labile P. These findings showed that HAP and PDP had a potential risk of excessive P-induced eutrophication. Meanwhile, more attention should be paid to the leaching loss of multiple metals because phosphate amendments might promote the leaching of some metals while immobilizing others.

Is it efficient to co-compost and co-vermicompost green waste with biochar and/or clay to reduce CO2 emissions? A short-term laboratory experiment on (vermi)composts with additives.

NASA Astrophysics Data System (ADS)

Barthod, Justine; Rumpel, Cornélia; Paradelo, Remigio; Dignac, Marie-France

2016-04-01

Intensive farming practices can lead to a depletion of soil organic matter, negatively impacting important soil properties such as structural stability, fertility and C storage. The addition of organic amendments such as compost and vermicompost, rich in carbon, helps maintaining soil organic matter levels or restoring degraded soils. Composting and vermicomposting are based on stabilization of organic matter through the mineralization of easily decomposable organic matter compounds, therefore releasing greenhouse gases, including CO2. The aim of this study was to evaluate the global potential reduction of such emissions by the use of additives (2:1 clay and/or biochar): during (vermi)composting processes and after use of the final products as soil amendments. We hypothesized that the interactions between the additives and organic matter may lead to carbon stabilization and that such interactions may be enhanced by the presence of worms (Eisenia). We added in different proportions clay (25% or 50%), biochar (10%) and a mixture of biochar (10%) with clay (25%) to pre-composted green waste. The CO2 emissions of the composting and vermicomposting processes were measured during 21 days. After that, the amendments were added to a loamy cambisol soil and the CO2 emissions were monitored during 30 days of a laboratory experiment. The most efficient treatments in terms of reducing global CO2 emissions were the co-vermicomposting process with 25% clay followed by co-composting with 50% clay and with 10% biochar plus 25% clay. In this treatment (vermicompost with 25% clay), the carbon emissions were decreased by up to 44% compared to regular compost. Addition of biochar reduced CO2 emissions only during composting. Co-composting with biochar could be a promising avenue to limit global CO2 emissions whereas in presence of worms clay additions are better suited. These findings suggest that the presence of worms increased the formation of organo-mineral associations and thus C protection up to a certain clay/organic matter ratio. This strategy could be used to enhance the stability of organic amendments and increase soil carbon sequestration.

Earthworms and priming of soil organic matter - The impact of food sources, food preferences and fauna - microbiota interactions

NASA Astrophysics Data System (ADS)

Potthoff, Martin; Wichern, Florian; Dyckmans, Jens; Joergensen, Rainer Georg

2016-04-01

Earthworms deeply interact with the processes of soil organic matter turnover in soil. Stabilization of carbon by soil aggregation and in the humus fraction of SOM are well known processes related to earthworm activity and burrowing. However, recent research on priming effects showed inconsistent effects for the impact of earthworm activity. Endogeic earthworms can induce apparent as well as true positive priming effects. The main finding is almost always that earthworm increase the CO2 production from soil. The sources of this carbon release can vary and seem to depend on a complex interaction of quantity and quality of available carbon sources including added substrates like straw or other compounds, food preferences and feeding behavior of earthworms, and soil properties. Referring to recent studies on earthworm effects on soil carbon storage and release (mainly Eck et al. 2015 Priming effects of Aporrectodea caliginosa on young rhizodeposits and old soil organic matter following wheat straw addition, European Journal of Soil Biology 70:38-45; Zareitalabad et al. 2010 Decomposition of 15N-labelled maize leaves in soil affected by endogeic geophagous Aporrectodea caliginosa, Soil Biology and Biochemistry 42(2):276-282; and Potthoff et al. 2001 Short-term effects of earthworm activity and straw amendment on the microbial C and N turnover in a remoistened arable soil after summer drought, Soil Biology and Biochemistry 33(4):583-591) we summaries the knowledge on earthworms and priming and come up with a conceptual approach and further research needs.

Electron harvest and treatment of amendment free municipal wastewater using microbial anodes: A case study

NASA Astrophysics Data System (ADS)

Rosa, Luis F. M.; Koch, Christin; Korth, Benjamin; Harnisch, Falk

2017-07-01

Microbial electrochemical technologies (METs) and especially microbial fuel cells (MFCs) are considered to allow energy harvest from the fuel wastewater during its treatment. However, the majority of studies use either "artificial" wastewater, amended wastewater, (i.e. with addition of chemicals), or pre-enriched microbial anodes. As these strategies might not be transferable to large scale, this study uses exclusively amendment free municipal wastewater as inoculum and sole carbon and energy source. It is shown that electrons can be harvested, at maximum current densities of 0.01 mA cm-2. In weekly cycles using batch systems (with 90 cm2 L-1 anode surface) only a minor fraction (<10%) of the available charge from COD-removal was turned into electricity by a highly diverse anodic microbial community. This performance is below those achieved by pre-enriched anodes or in amended wastewater studies, illustrating the need for more fundamental, application relevant studies.

Effect of microaerobic fermentation in preprocessing fibrous lignocellulosic materials.

PubMed

Alattar, Manar Arica; Green, Terrence R; Henry, Jordan; Gulca, Vitalie; Tizazu, Mikias; Bergstrom, Robby; Popa, Radu

2012-06-01

Amending soil with organic matter is common in agricultural and logging practices. Such amendments have benefits to soil fertility and crop yields. These benefits may be increased if material is preprocessed before introduction into soil. We analyzed the efficiency of microaerobic fermentation (MF), also referred to as Bokashi, in preprocessing fibrous lignocellulosic (FLC) organic materials using varying produce amendments and leachate treatments. Adding produce amendments increased leachate production and fermentation rates and decreased the biological oxygen demand of the leachate. Continuously draining leachate without returning it to the fermentors led to acidification and decreased concentrations of polysaccharides (PS) in leachates. PS fragmentation and the production of soluble metabolites and gases stabilized in fermentors in about 2-4 weeks. About 2 % of the carbon content was lost as CO(2). PS degradation rates, upon introduction of processed materials into soil, were similar to unfermented FLC. Our results indicate that MF is insufficient for adequate preprocessing of FLC material.

Winery vermicomposts to control the leaching of diuron, imidacloprid and their metabolites: role of dissolved organic carbon content.

PubMed

Fernández-Bayo, Jesús D; Nogales, Rogelio; Romero, Esperanza

2015-01-01

Soil organic amendment addition is an effective practice in Mediterranean areas due to its associated high agricultural benefits and its potential to reduce the pesticide impact on water resources. However, their metabolites have received scarce attention, even when they may pose more risk than their parent compounds. Two winery vermicomposts obtained from spent grape marc (V1) and the mixture vine shoot-biosolid vinasses (V2) have been investigated as low cost organic amendments to minimize the leaching of diuron, imidacloprid and their metabolites in columns packed with a sandy loam (S1) and a silty-clay loam soil (S2) under steady state flow conditions. In the unamended soil columns, leached amounts of diuron were 75% and 53% in S1 and S2, respectively. Its metabolites (3-(3,4-dichlorophenyl)-1-methylurea, DPMU; and 3,4-dichlorophenylurea, DPU) percolated less than 35% of the total applied amount. The amount of the metabolite 3,4-dichloroaniline (DCA) was 2% and 30% for S1 and S2, respectively. Leaching of imidacloprid was 79% and 96% for S1 and S2, respectively, while its metabolite 6-chloronicotinic acid (CNA) was entirely leached. In the vermicompost-amended columns, the leaching of diuron was reduced 2 to 3-fold. DPMU and DPU were also significantly reduced (more than 6-fold). DCA did not appear in any of the leachates of the amended soil columns. Imidacloprid leaching was reduced 1 to 2-folds in the amended columns. The amendments did not affect the transport of CNA. The dissolved organic carbon (DOC) from the vermicomposts did not enhance pesticide transport throughout the soil in any case. This qualitative study presents these vermicomposts as an effective potential low-cost tool in reducing pesticide and metabolite leaching. The next step would be to test them under more realistic conditions.

Microbial Growth and Metabolism in Soil - Refining the Interpretation of Carbon Use Efficiency

NASA Astrophysics Data System (ADS)

Geyer, K.; Frey, S. D.

2016-12-01

Carbon use efficiency (CUE) describes a critical step in the terrestrial carbon cycle where microorganisms partition organic carbon (C) between stabilized organic forms and CO2. Application of this concept, however, begins with accurate measurements of CUE. Both traditional and developing approaches still depend on numerous assumptions that render them difficult to interpret and potentially incompatible with one another. Here we explore the soil processes inherent to traditional (e.g., substrate-based, biomass-based) and emerging (e.g., growth rate-based, calorimetry) CUE techniques in order to better understand the information they provide. Soil from the Harvard Forest Long Term Ecological Research (LTER) site in Massachusetts, USA, was amended with both 13C-glucose and 18O-water and monitored over 72 h for changes in dissolved organic carbon (DOC), respiration (R), microbial biomass (MB), DNA synthesis, and heat flux (Q). Four different CUE estimates were calculated: 1) (ΔDOC - R)/ΔDOC (substrate-based), 2) Δ13C-MB/(Δ13C-MB + R) (biomass-based), 3) Δ18O-DNA/(Δ18O-DNA + R) (growth rate-based), 4) Q/R (energy-based). Our results indicate that microbial growth (estimated by both 13C and 18O techniques) was delayed for 40 h after amendment even though DOC had declined to pre-amendment levels within 48 h. Respiration and heat flux also peaked after 40 h. Although these soils have a relatively high organic C content (5% C), respired CO2 was greater than 88% glucose-derived throughout the experiment. All estimates of microbial growth (Spearman's ρ >0.83, p<0.01) and efficiency (Spearman's ρ >0.65, p<0.05) were positively correlated, but strong differences in the magnitude of CUE suggest incomplete C accounting. This work increases the transparency of CUE techniques for researchers looking to choose the most appropriate measure for their scale of inquiry or to use CUE estimates in modeling applications.

Metal availability, soil nutrient, and enzyme activity in response to application of organic amendments in Cd-contaminated soil.

PubMed

Yang, Zhanbiao; Liu, Lixia; Lv, Yanfeng; Cheng, Zhang; Xu, Xiaoxun; Xian, Junren; Zhu, Xuemei; Yang, Yuanxiang

2018-01-01

The study investigated the effects of organic amendments: green tea amendment (GTA) and oil cake amendment (OCA) on Cd bioavailability, soil nutrients, and soil enzyme activity in Cd-contaminated soil. The amendments were added to the soil at the doses of 1, 3, and 5% and were incubated for 45 days. Then, pakchoi cabbage was planted to test the remediation effect of the above two organic amendments. The diethylenetriaminepentaacetic acid (DTPA)-extractable Cd in GTA and OCA treatments was reduced by 14.69-27.51 and 13.75-68.77%, respectively, compared to no amendment-applied treatment. The application of GTA and OCA notably decreased the proportion of exchangeable fraction of Cd, but increased the percentage of oxide and organic-bound fraction of Cd, thereby suppressing the uptake by pakchoi cabbage. Cd concentration of aboveground parts decreased by 8.21-18.05 and 7.77-35.89% in GTA and OCA treatments, respectively. Relative to the no amendment-applied treatment, both GTA and OCA had enhanced soil nutrients and enzyme activities largely. Redundancy analysis showed that organic matter, total P, available N, and DTPA-extractable Cd significantly affected the enzyme activities. Furthermore, the application of OCA at the dose of 5% was more effective in reducing bioavailable Cd, enhancing soil available nutrients and urease and catalase activities in contaminated soil. These results indicated that oil cake should be used to immobilize metal and improve fertility and quality of Cd-contaminated soil.

Effects of Cd and Pb on soil microbial community structure and activities.

PubMed

Khan, Sardar; Hesham, Abd El-Latif; Qiao, Min; Rehman, Shafiqur; He, Ji-Zheng

2010-02-01

Soil contamination with heavy metals occurs as a result of both anthropogenic and natural activities. Heavy metals could have long-term hazardous impacts on the health of soil ecosystems and adverse influences on soil biological processes. Soil enzymatic activities are recognized as sensors towards any natural and anthropogenic disturbance occurring in the soil ecosystem. Similarly, microbial biomass carbon (MBC) is also considered as one of the important soil biological activities frequently influenced by heavy metal contamination. The polymerase chain reaction-denaturing gradient gel electrophoresis (DGGE) has recently been used to investigate changes in soil microbial community composition in response to environmental stresses. Soil microbial community structure and activities are difficult to elucidate using single monitoring approach; therefore, for a better insight and complete depiction of the soil microbial situation, different approaches need to be used. This study was conducted in a greenhouse for a period of 12 weeks to evaluate the changes in indigenous microbial community structure and activities in the soil amended with different application rates of Cd, Pb, and Cd/Pb mix. In a field environment, soil is contaminated with single or mixed heavy metals; so that, in this research, we used the selected metals in both single and mixed forms at different application rates and investigated their toxic effects on microbial community structure and activities, using soil enzyme assays, plate counting, and advanced molecular DGGE technique. Soil microbial activities, including acid phosphatase (ACP), urease (URE), and MBC, and microbial community structure were studied. A soil sample (0-20 cm) with an unknown history of heavy metal contamination was collected and amended with Cd, Pb, and Cd/Pb mix using the CdSO(4) and Pb(NO(3))(2) solutions at different application rates. The amended soils were incubated in the greenhouse at 25 +/- 4 degrees C and 60% water-holding capacity for 12 weeks. During the incubation period, samples were collected from each pot at 0, 2, 9, and 12 weeks for enzyme assays, MBC, numeration of microbes, and DNA extraction. Fumigation-extraction method was used to measure the MBC, while plate counting techniques were used to numerate viable heterotrophic bacteria, fungi, and actinomycetes. Soil DNAs were extracted from the samples and used for DGGE analysis. ACP, URE, and MBC activities of microbial community were significantly lower (p < 0.05) in the metal-amended samples than those in the control. The enzyme inhibition extent was obvious between different incubation periods and varied as the incubation proceeded, and the highest rate was detected in the samples after 2 weeks. However, the lowest values of ACP and URE activities (35.6% and 36.6% of the control, respectively) were found in the Cd(3)/Pb(3)-treated sample after 2 weeks. Similarly, MBC was strongly decreased in both Cd/Pb-amended samples and highest reduction (52.4%) was detected for Cd(3)/Pb(3) treatment. The number of bacteria and actinomycetes were significantly decreased in the heavy metal-amended samples compared to the control, while fungal cells were not significantly different (from 2.3% to 23.87%). In this study, the DGGE profile indicated that the high dose of metal amendment caused a greater change in the number of bands. DGGE banding patterns confirmed that the addition of metals had a significant impact on microbial community structure. In soil ecosystem, heavy metals exhibit toxicological effects on soil microbes which may lead to the decrease of their numbers and activities. This study demonstrated that toxicological effects of heavy metals on soil microbial community structure and activities depend largely on the type and concentration of metal and incubation time. The inhibition extent varied widely among different incubation periods for these enzymes. Furthermore, the rapid inhibition in microbial activities such as ACP, URE, and MBC were observed in the 2 weeks, which should be related to the fact that the microbes were suddenly exposed to heavy metals. The increased inhibition of soil microbial activities is likely to be related to tolerance and adaptation of the microbial community, concentration of pollutants, and mechanisms of heavy metals. The DGGE profile has shown that the structure of the bacterial community changed in amended heavy metal samples. In this research, the microbial community structure was highly affected, consistent with the lower microbial activities in different levels of heavy metals. Furthermore, a great community change in this study, particularly at a high level of contamination, was probably a result of metal toxicity and also unavailability of nutrients because no nutrients were supplied during the whole incubation period. The added concentrations of heavy metals have changed the soil microbial community structure and activities. The highest inhibitory effects on soil microbial activities were observed at 2 weeks of incubation. The bacteria were more sensitive than actinomycetes and fungi. The DGGE profile indicated that bacterial community structure was changed in the Cd/Pb-amended samples, particularly at high concentrations. The investigation of soil microbial community structure and activities together could give more reliable and accurate information about the toxic effects of heavy metals on soil health.

The 26th Amendment and Youth Voting Rights.

ERIC Educational Resources Information Center

Schamel, Wynell

1996-01-01

Describes learning activities to be used in conjunction with a facsimile of the 92nd Congress's joint resolution passing the 26th Amendment extending the voting franchise to 18-year-olds. These activities include document analysis, time lines, class discussions, and storytelling. Briefly reviews the amendment process. (MJP)

Lability of High Molecular Weight Dissolved Organic Matter Polysaccharides Increases with Mild Acid or Base Treatment.

NASA Astrophysics Data System (ADS)

Pedler Sherwood, B.; Sosa, O.; Nelson, C. E.; Repeta, D.; DeLong, E.

2016-02-01

Approximately 662 Pg of dissolved organic carbon (DOC) has accumulated in the global ocean, yet the biological and chemical constraints on DOC turnover remain poorly understood. High molecular weight dissolved organic matter (HMWDOM) is largely comprised of semi-labile polysaccharides. These polysaccharides resist degradation even in the presence of nutrient amendments, suggesting unknown factors of polysaccharide composition affect microbial degradation. In a series of microcosm incubations conducted at station ALOHA in the North Pacific Subtropical Gyre, we tested the affect of mild base (KOH-DOM) and acid (HCl-DOM) treatments on polysaccharide lability. KOH-DOM, HCl-DOM, and untreated HMWDOM was added to seawater from the deep chlorophyll maximum and 200m. Microcosms amended with KOH-DOM and HCl-DOM yielded higher bacterial abundance and greater carbon drawdown relative to untreated HMWDOM and unamended controls. Microcosms amended with KOH-DOM and HCl-DOM also showed significant production of fluorescent DOM (fDOM), whereas untreated HMWDOM and unamended controls showed a net decrease in fDOM as measured by parallel factor analysis of DOM excitation-emission spectra. Metagenomic analyses revealed that microcosms amended with untreated HMWDOM and controls became dominated by Alteromonas genera ( 60% total sequence reads). In contrast, KOH-DOM and HCl-DOM amended microcosms yielded greater bacterial diversity; Alteromonas genera comprised 25% of sequence reads, with differences primarily accounted for by proportional increases in vibrio, roseobacter, rugeria and marinomonas clades. Transcriptomic analyses identified differential gene expression during growth on each DOM fraction. This study provides new insight into specific chemical moieties that may limit the bacterial degradation rate of semi-labile HMWDOM in the ocean.

Functional Diversity of Microbial Communities in Sludge-Amended Soils

NASA Astrophysics Data System (ADS)

Sun, Y. H.; Yang, Z. H.; Zhao, J. J.; Li, Q.

The BIOLOG method was applied to exploration of functional diversity of soil microbial communities in sludge-amended soils sampled from the Yangtze River Delta. Results indicated that metabolic profile, functional diversity indexes and Kinetic parameters of the soil microbial communities changed following soil amendment with sewage sludge, suggesting that the changes occurred in population of the microbes capable of exploiting carbon substrates and in this capability as well. The kinetic study of the functional diversity revealed that the metabolic profile of the soil microbial communities exhibited non-linear correlation with the incubation time, showing a curse of sigmoid that fits the dynamic model of growth of the soil microbial communities. In all the treatments, except for treatments of coastal fluvo-aquic soil amended with fresh sludge and dried sludge from Hangzhou, kinetic parameters K and r of the functional diversity of the soil microbial communities decreased significantly and parameter S increased. Changes in characteristics of the functional diversity well reflected differences in C utilizing capacity and model of the soil microbial communities in the sludge-amended soils, and changes in functional diversity of the soil microbial communities in a particular eco-environment, like soil amended with sewage sludge.

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.

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.

Influence of activated carbon and biochar on phytotoxicity of air-dried sewage sludges to Lepidium sativum.

PubMed

Oleszczuk, Patryk; Rycaj, Marcin; Lehmann, Johannes; Cornelissen, Gerard

2012-06-01

The goal of the research was to determine the phytotoxicity (using Lepidium sativum) of two activated carbon/biochar-amended sewage sludges. Apart from the impact of the AC/biochar dose, the influence of biochar particle diameter (<300, 300-500 and >500 μm) and the influence of the contact time (7, 60, 90 days) between AC/biochar and sewage sludges on their phytotoxicity was also assessed. No negative impact of sewage sludges on seed germination was observed (P>0.05). The application of AC or biochar to the sludges positively affected root growth by reducing the harmful effect by 7.8 to 42% depending on the material used. Furthermore, the reduction range clearly depended on the type of sewage sludge. No differences were observed in the inhibition of the toxic effect between both biochar types used and the biochar particle size. The extension of the contact time between AC/biochar and sewage sludges had a negative impact on root growth. Copyright © 2012 Elsevier Inc. All rights reserved.

Granular activated carbon as nucleating agent for aerobic sludge granulation: Effect of GAC size on velocity field differences (GAC versus flocs) and aggregation behavior.

PubMed

Zhou, Jia-Heng; Zhao, Hang; Hu, Miao; Yu, Hai-Tian; Xu, Xiang-Yang; Vidonish, Julia; Alvarez, Pedro J J; Zhu, Liang

2015-12-01

Initial cell aggregation plays an important role in the formation of aerobic granules. In this study, three parallel aerobic granular sludge reactors treating low-strength wastewater were established using granular activated carbon (GAC) of different sizes as the nucleating agent. A novel visual quantitative evaluation method was used to discern how GAC size affects velocity field differences (GAC versus flocs) and aggregation behavior during sludge granulation. Results showed that sludge granulation was significantly enhanced by addition of 0.2mm GAC. However, there was no obvious improvement in granulation in reactor amended with 0.6mm GAC. Hydraulic analysis revealed that increase of GAC size enhanced the velocity field difference between flocs and GAC, which decreased the lifecycle and fraction of flocs-GAC aggregates. Overall, based on analysis of aggregation behavior, GAC of suitable sizes (0.2mm) can serve as the nucleating agent to accelerate flocs-GAC coaggregation and formation of aerobic granules. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of granular activated carbon on methane removal performance and methanotrophic community of a lab-scale bioreactor.

PubMed

Lee, Eun-Hee; Choi, Sun-Ah; Yi, Taewoo; Kim, Tae Gwan; Lee, Sang-Don; Cho, Kyung-Suk

2015-01-01

Two identical lab-scale bioreactor systems were operated to examine the effects of granular activated carbon (GAC) on methane removal performance and methanotrophic community. Both bioreactor systems removed methane completely at a CH4 loading rate of 71.2 g-CH4·d(-1) for 17 days. However, the methane removal efficiency declined to 88% in the bioreactor without GAC, while the bioreactor amended with GAC showed greater methane removal efficiency of 97% at a CH4 loading rate of 107.5 g-CH4·d(-1). Although quantitative real-time PCR showed that methanotrophic populations were similar levels of 5-10 × 10(8) pmoA gene copy number·VSS(-1) in both systems, GAC addition changed the methanotrophic community composition of the bioreactor systems. Microarray assay revealed that GAC enhanced the type I methanotrophic genera including Methylobacter, Methylomicrobium, and Methylomonas of the system, which suggests that GAC probably provided a favorable environment for type I methanotrophs. These results indicated that GAC is a promising support material in bioreactor systems for CH4 mitigation.

Recovery of community genomes to assess subsurface metabolic potential: exploiting the capacity of next generation sequencing-based metagenomics

NASA Astrophysics Data System (ADS)

Wrighton, K. C.; Thomas, B.; Miller, C. S.; Sharon, I.; Wilkins, M. J.; VerBerkmoes, N. C.; Handley, K. M.; Lipton, M. S.; Hettich, R. L.; Williams, K. H.; Long, P. E.; Banfield, J. F.

2011-12-01

With the goal of developing a deterministic understanding of the microbiological and geochemical processes controlling subsurface environments, groundwater bacterial communities were collected from the Rifle Integrated Field Research Challenge (IFRC) site. Biomass from three temporal acetate-stimulated groundwater samples were collected during a period of dominant Fe(III)-reduction, in a region of the aquifer that had previously received acetate amendment the year prior. Phylogenetic analysis revealed a diverse Bacterial community, notably devoid of Archaea with 249 taxa from 9 Bacterial phyla including the dominance of uncultured candidate divisions, BD1-5, OD1, and OP11. We have reconstructed 86 partial to near-complete genomes and have performed a detailed characterization of the underlying metabolic potential of the ecosystem. We assessed the natural variation and redundancy in multi-heme c-type cytochromes, sulfite reductases, and central carbon metabolic pathways. Deep genomic sampling indicated the community contained various metabolic pathways: sulfur oxidation coupled to microaerophilic conditions, nitrate reduction with both acetate and inorganic compounds as donors, carbon and nitrogen fixation, antibiotic warfare, and heavy-metal detoxification. Proteomic investigations using predicted proteins from metagenomics corroborated that acetate oxidation is coupled to reduction of oxygen, sulfur, nitrogen, and iron across the samples. Of particular interest was the detection of acetate oxidizing and sulfate reducing proteins from a Desulfotalea-like bacterium in all three time points, suggesting that aqueous sulfide produced by active sulfate-reducing bacteria could contribute to abiotic iron reduction during the dominant iron reduction phase. Additionally, proteogenomic analysis verified that a large portion of the community, including members of the uncultivated BD1-5, are obligate fermenters, characterized by the presence of hydrogen-evolving hydrogenases, the capacity to oxidize complex organic carbon, as well as lack of membrane bound electron transport chains and an incomplete citric acid cycle. We propose that these organisms grow cryptically on residual biomass from previous biostimulation experiments and thus demonstrate that resource utilization and turnover in the aquifer can be decoupled from existing acetate amendment and external terminal electron accepting processes. In addition to the first recovery of multiple genomes from these novel candidate divisions, our community genomic approach uncovered viral diversity not yet observed at the site, with the reconstruction of six phage genomes and the presence of CRISPR loci detected in bacterial genomes from diverse lineages. These findings have implications for predictive ecosystem modeling, highlighting the importance of integrating the response, adaptation, as well as biological and geochemical feedback mechanisms existing within complex subsurface communities to long term organic carbon amendment.

Evolutionary and ecophysiological significance of sugar utilization by the peat moss Sphagnum compactum (Sphagnaceae) and the common charophycean associates Cylindrocystis brebissonii and Mougeotia sp. (Zygnemataceae).

PubMed

Graham, Linda E; Kim, Eunsoo; Arancibia-Avila, Patricia; Graham, James M; Wilcox, Lee W

2010-09-01

The goal of this study was to illuminate the evolutionary history and ecological importance of plant mixotrophy-the uptake and utilization of exogenous organic compounds. • We quantitatively assessed the effect of sugar amendments on laboratory growth of Sphagnum compactum as a representative emergent peat moss and two species of ecologically associated zygnematalean algae, Cylindrocystis brebissonii and Mougeotia sp. • Together with observations published elsewhere, our results suggest that under carbon or light limitation, the uptake of exogenous sugars by cells of charophycean algae and peat mosses may help these organisms maintain positive carbon balance. Utilization of 1% glucose by aquatic-grown algae helped to relieve dissolved inorganic carbon limitation, enhancing photoautotrophic growth by factors of 9.0 and 1.7, respectively. After an 8-wk growth period, amendments of 1% and 2% glucose enhanced air-grown moss biomass by 28 and 39 times, respectively, that of controls lacking sugar amendments. After 9 wk, 1% fructose enhanced biomass by 21 times, and 2% sucrose enhanced biomass by 31 times. • Our results indicate that plant mixotrophy is an early-evolved trait. The results also indicate that quantitative differences in sugar utilization by bryophytes and charophycean algae correlate with relative investments in protective cell-wall polyphenolics measured in previous studies, suggesting that sugar utilization may subsidize the cost of producing phenolic wall compounds in bryophytes.

Varying Inundation Regimes Differentially Affect Natural and Sand-Amended Marsh Sediments.

PubMed

Wigand, C; Sundberg, K; Hanson, A; Davey, E; Johnson, R; Watson, E; Morris, J

2016-01-01

Climate change is altering sea level rise rates and precipitation patterns worldwide. Coastal wetlands are vulnerable to these changes. System responses to stressors are important for resource managers and environmental stewards to understand in order to best manage them. Thin layer sand or sediment application to drowning and eroding marshes is one approach to build elevation and resilience. The above- and below-ground structure, soil carbon dioxide emissions, and pore water constituents in vegetated natural marsh sediments and sand-amended sediments were examined at varying inundation regimes between mean sea level and mean high water (0.82 m NAVD88 to 1.49 m NAVD88) in a field experiment at Laws Point, part of the Plum Island Sound Estuary (MA). Significantly lower salinities, pH, sulfides, phosphates, and ammonium were measured in the sand-amended sediments than in the natural sediments. In natural sediments there was a pattern of increasing salinity with increasing elevation while in the sand-amended sediments the trend was reversed, showing decreasing salinity with increasing elevation. Sulfide concentrations generally increased from low to high inundation with highest concentrations at the highest inundation (i.e., at the lowest elevations). High pore water phosphate concentrations were measured at low elevations in the natural sediments, but the sand-amended treatments had mostly low concentrations of phosphate and no consistent pattern with elevation. At the end of the experiment the lowest elevations generally had the highest measures of pore water ammonium. Soil carbon dioxide emissions were greatest in the sand-amended mesocosms and at higher elevations. Differences in coarse root and rhizome abundances and volumes among the sediment treatments were detected with CT imaging, but by 20 weeks the natural and sand-amended treatments showed similar total belowground biomass at the intermediate and high elevations. Although differences in pore water nutrient concentrations, pH, salinity, and belowground root and rhizome morphology were detected between the natural and sand-amended sediments, similar belowground productivity and total biomass were measured by the end of the growing season. Since the belowground productivity supports organic matter accumulation and peat buildup in marshes, our results suggest that thin layer sand or sediment application is a viable climate adaptation action to build elevation and coastal resiliency, especially in areas with low natural sediment supplies.

L-asparaginase and L-glutaminase activities in submerged rice soil amended with municipal solid waste compost and decomposed cow manure.

PubMed

Bhattacharyya, P; Chakrabarti, K; Tripathy, S; Chakraborty, A; Kim, K; Kim, S H

2007-01-01

The field study was conducted to evaluate the effect of municipal solid waste compost (MSWC) as a soil amendment on L-asparaginase (LA) and L-glutaminase (LG) activities. Experiments were conducted during the wet seasons of 1997, 1998 and 1999 on rice grown under a submerged condition, at the Agriculture Experimental Farm, Calcutta University at Baruipur, West Bengal, India. The treatments consisted of control, no input; MSWC, at 60 Kg N ha(- 1); well-decomposed cow manure (DCM), at 60 Kg N ha(- 1); MSWC (30 Kg N ha(- 1)) + Urea (U) (30 Kg N ha(- 1)); DCM (30 Kg N ha(- 1)) + U (30 Kg N ha(- 1)) and Fertilizer, (at 60:30:30 NPK kg ha(- 1)) through urea, single superphosphate and muriate of potash respectively). LA and LG activities alone and their ratio with organic-C (ratio index value, RIV), straw and grain yield were higher in DCM than MSWC-treated soils, due to higher amount of biogenic organic materials like water-soluble organic carbon, carbohydrate and mineralizable nitrogen in the former. The studied parameters were higher when urea was integrated with DCM or MSWC, compared to their single applications. The heavy metals in MSWC did not detrimentally influence the above-measured activities of soil. In the event of long term MSWC application, changes in soil quality parameters should be monitored regularly, since heavy metals once entering into soil persist over a long period.

Enhancement of Population Size of a Biological Control Agent and Efficacy in Control of Bacterial Speck of Tomato through Salicylate and Ammonium Sulfate Amendments

PubMed Central

Ji, Pingsheng; Wilson, Mark

2003-01-01

Sodium salicylate and ammonium sulfate were applied to leaf surfaces along with suspensions of the biological control agents Pseudomonas syringae Cit7(pNAH7), which catabolizes salicylate, and Cit7, which does not catabolize salicylate, to determine whether enhanced biological control of bacterial speck of tomato could be achieved. Foliar amendment with salicylate alone significantly enhanced the population size and the efficacy of Cit7(pNAH7), but not of Cit7, on tomato leaves. Application of ammonium sulfate alone did not result in enhanced population size or biological control efficacy of either Cit7(pNAH7) or Cit7; however, when foliar amendments with both sodium salicylate and ammonium sulfate were applied, a trend toward further increases in population size and biological control efficacy of Cit7(pNAH7) was observed. This study demonstrates the potential of using a selective carbon source to improve the efficacy of a bacterial biological control agent in the control of a bacterial plant disease and supports previous conclusions that the growth of P. syringae in the phyllosphere is primarily carbon limited and secondarily nitrogen limited. PMID:12571060

Impact of biochar amendment on soil water soluble carbon in the context of extreme hydrological events.

PubMed

Wang, Daoyuan; Griffin, Deirdre E; Parikh, Sanjai J; Scow, Kate M

2016-10-01

Biochar amendments to soil have been promoted as a low cost carbon (C) sequestration strategy as well as a way to increase nutrient retention and remediate contaminants. If biochar is to become part of a long-term management strategy, it is important to consider its positive and negative impacts, and their trade-offs, on soil organic matter (SOM) and soluble C under different hydrological conditions such as prolonged drought or frequent wet-dry cycles. A 52-week incubation experiment measuring the influence of biochar on soil water soluble C under different soil moisture conditions (wet, dry, or wet-dry cycles) indicated that, in general, dry and wet-dry cycles increased water soluble C, and biochar addition further increased release of water soluble C from native SOM. Biochar amendment appeared to increase transformation of native SOM to water soluble C, based on specific ultraviolet absorption (SUVA) and C stable isotope composition; however, the increased amount of water soluble C from native SOM is less than 1% of total biochar C. The impacts of biochar on water soluble C need to be carefully considered when applying biochar to agricultural soil. Copyright © 2016 Elsevier Ltd. All rights reserved.

Nutrient Supplying Potential of Different Spent Mushroom Substrate Preparations as Soil Amendment in a Potting Media

NASA Astrophysics Data System (ADS)

Ultra, VU, Jr.; Ong Sotto, JME; Punzalan, MR

2018-03-01

A three consecutive cropping experiment was conducted to evaluate the nutrient supplying potential of different preparations of the spent mushroom substrate as an amendment of growing media for potted plants using pechay as test plant. There are 12 treatment combinations consisted 4 types of growing media containing soil alone and mixtures of soil with fresh SMS (FSMS), weathered SMS (WSMS) and carbonized SMS (CSMS) in combination with 0%, 50% or 100% recommended rate (RR) of nitrogen fertilizer. Succeeding two trials were conducted on the same pots and treatment assignments. The high yield of pechay during the first and second crop was observed on WSMS and CSMS treatments FSMS media produced high yields only during the 3rd crop. Yield was increased by N fertilizer in WSMS and CSMS treatments but not in FSMS. The growth differences is attributed to differences in available nutrients and C/N ratio between treatments. WSMS and CSMS increased the available N while FSMS immobilized N and other nutrients indicting that weathered SMS and carbonized SMS are more suitable as a component of potting media or as soil amendments without detrimental effect on immobilization and availability of nutrients.

Low carbon amendment rates during anaerobic soil disinfestation (ASD) at moderate soil temperatures do not decrease viability of Sclerotinia sclerotiorum sclerotia or Fusarium root rot of common bean

USDA-ARS?s Scientific Manuscript database

Anaerobic soil disinfestation (ASD; also termed biological soil disinfestation) is a non-chemical process which includes 1) soil incorporation of a labile carbon (C) source, 2) mulching with polyethylene film to limit gas exchange, and 3) drip irrigation to saturation of the topsoil or bedded area. ...

Immobilisation of lead and zinc in contaminated soil using compost derived from industrial eggshell.

PubMed

Soares, Micaela A R; Quina, Margarida J; Quinta-Ferreira, Rosa M

2015-12-01

This study aims to evaluate the capacity of a compost obtained by co-composting of industrial eggshell (CES) to immobilise lead (Pb) and zinc (Zn) in an acidic soil contaminated by mining activities. Mature compost without eggshell (CWES) and natural eggshell (ES) were also tested as soil amendments for comparison purposes. Three different application rates were used for each material, ensuring the same quantity in terms of neutralizing capacity. Incubation experiments were conducted under controlled conditions and CO2 emissions monitored for 94 days. The environmental availability of Pb and Zn in the amended soil was assessed and bioassays were performed at the end of the incubation period. When eggshells were present, the CES compost raised the soil pH to values higher than 6 and reduced the soil mobile fraction for both Pb and Zn, in more than 95%. Soil toxicity towards Vibrio fischeri was also suppressed and environmental risk decreased to "low level". However, the immobilisation in the acid insoluble soil component was significantly achieved only for Zn. In addition, regarding soil carbon dynamics the CO2-C emissions were enhanced, mainly in the case of the highest rate of amendment. Both first order-E and parallel first order models may adequately describe the kinetic data of CO2-C cumulative release. Without eggshells, the CWES compost revealed limited effect on heavy metals immobilisation, likely due to its small capacity to correct soil acidity, at lower application rates. Using solely eggshells, the ES waste had similar outcomes when compared with CES, but at the higher application rate, CO2 emissions were enhanced with the eggshell compost due to the contribution of biotic carbon present therein. Therefore, this study points out that CES is an effective liming material and may be used for in situ remediation of contaminated soil with Pb and Zn. Copyright © 2015 Elsevier Ltd. All rights reserved.

15 CFR 922.132 - Prohibited or otherwise regulated activities.

Code of Federal Regulations, 2014 CFR

2014-01-01

..., as amended, (MMPA), 16 U.S.C. 1361 et seq., Endangered Species Act, as amended, (ESA), 16 U.S.C. 1531...) approved in accordance with section 312 of the Federal Water Pollution Control Act, as amended (FWPCA), 33... effective date of Sanctuary designation (January 1, 1993), provided that the activity is pursuant to, and...

15 CFR 922.132 - Prohibited or otherwise regulated activities.

Code of Federal Regulations, 2013 CFR

2013-01-01

..., as amended, (MMPA), 16 U.S.C. 1361 et seq., Endangered Species Act, as amended, (ESA), 16 U.S.C. 1531...) approved in accordance with section 312 of the Federal Water Pollution Control Act, as amended (FWPCA), 33... effective date of Sanctuary designation (January 1, 1993), provided that the activity is pursuant to, and...

15 CFR 922.132 - Prohibited or otherwise regulated activities.

Code of Federal Regulations, 2012 CFR

2012-01-01

..., as amended, (MMPA), 16 U.S.C. 1361 et seq., Endangered Species Act, as amended, (ESA), 16 U.S.C. 1531...) approved in accordance with section 312 of the Federal Water Pollution Control Act, as amended (FWPCA), 33... effective date of Sanctuary designation (January 1, 1993), provided that the activity is pursuant to, and...

Fate of Soil Organic Carbon and Polycyclic Aromatic Hydrocarbons in a Vineyard Soil Treated with Biochar.

PubMed

Rombolà, Alessandro G; Meredith, Will; Snape, Colin E; Baronti, Silvia; Genesio, Lorenzo; Vaccari, Francesco Primo; Miglietta, Franco; Fabbri, Daniele

2015-09-15

The effect of biochar addition on the levels of black carbon (BC) and polcyclic aromatic hydrocarbons (PAHs) in a vineyard soil in central Italy was investigated within a two year period. Hydropyrolysis (HyPy) was used to determine the contents of BC (BCHyPy) in the amended and control soils, while the hydrocarbon composition of the semi-labile (non-BCHyPy) fraction released by HyPy was determined by gas chromatography-mass spectrometry, together with the solvent-extractable PAHs. The concentrations of these three polycyclic aromatic carbon reservoirs changed and impacted differently the soil organic carbon over the period of the trial. The addition of biochar (33 ton dry biochar ha(-1)) gave rise to a sharp increase in soil organic carbon, which could be accounted for by an increase in BCHyPy. Over time, the concentration of BCHyPy decreased significantly from 36 to 23 mg g(-1) and as a carbon percentage from 79% to 61%. No clear time trends were observed for the non-BCHyPy PAHs varying from 39 to 34 μg g(-1) in treated soils, not significantly different from control soils. However, the concentrations of extractable PAHs increased markedly in the amended soils and decreased with time from 153 to 78 ng g(-1) remaining always higher than those in untreated soil. The extent of the BCHyPy loss was more compatible with physical rather than chemical processes.

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.

Improvement of soil characteristics and growth of Dorycnium pentaphyllum by amendment with agrowastes and inoculation with AM fungi and/or the yeast Yarowia lipolytica.

PubMed

Medina, A; Vassileva, M; Caravaca, F; Roldán, A; Azcón, R

2004-08-01

The effectiveness of two microbiologically treated agrowastes [dry olive cake (DOC) and/or sugar beet (SB)] on plant growth, soil enzymatic activities and other soil characteristics was determined in a natural soil from a desertified area. Dorycnium pentaphyllum, a legume plant adapted to stress situations, was the test plant to evaluate the effect of inoculation of native arbuscular mycorrhizal (AM) fungi and/or Yarowia lipolytica (a dry soil adapted yeast) on amended and non-amended soils. Plant growth and nutrition, symbiotic developments and soil enzymatic activities were limited in non-amended soil where microbial inoculations did not improve plant development. The lack of nodules formation and AM colonization can explain the limited plant growth in this natural soil. The effectiveness and performance of inocula applied was only evident in amended soils. AM colonization and spores number in natural soil were increased by amendments and the inoculation with Y. lipolytica promoted this value. The effect of the inoculations on plant N-acquisition was only important in AM-inoculated plants growing in SB medium. Enzymatic activities as urease and protease activities were particularly increased in DOC amended soil meanwhile dehydrogenase activity was greatest in treatments inoculated with Y. lipolytica in SB added soil. The biological activities in rhizosphere of agrowaste amended soil, used as indices of changes in soil properties and fertility, were affected not only by the nature of amendments but also by the inoculant applied. All these results show that the lignocellulosic agrowastes treated with a selected microorganism and its further interaction with beneficial microbial groups (native AM fungi and/or Y. lipolytica) is a useful tool to modify soil physico-chemical, biological and fertility properties that enhance the plant performance probably by making nutrients more available to plants.

[Soil biological activities at maize seedling stage under application of slow/controlled release nitrogen fertilizers].

PubMed

Li, Dongpo; Wu, Zhijie; Chen, Lijun; Liang, Chenghua; Zhang, Lili; Wang, Weicheng; Yang, Defu

2006-06-01

With pot experiment and simulating field ecological environment, this paper studied the effects of different slow/ controlled release N fertilizers on the soil nitrate - reductase and urease activities and microbial biomass C and N at maize seedling stage. The results showed that granular urea amended with dicyandiamide (DCD) and N-(n-bultyl) thiophosphoric triamide (NBPT) induced the highest soil nitrate-reductase activity, granular urea brought about the highest soil urease activity and microbial biomass C and N, while starch acetate (SA)-coated granular urea, SA-coated granular urea amended with DCD, methyl methacrylate (MMA) -coated granular urea amended with DCD, and no N fertilization gave a higher soil urease activity. Soil microbial C and N had a similar variation trend after applying various kinds of test slow/controlled release N fertilizers, and were the lowest after applying SA-coated granular urea amended with DCD and NBPT. Coated granular urea amended with inhibitors had a stronger effect on soil biological activities than coated granular urea, and MMA-coating had a better effect than SA-coating.

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

Carbon Balance in an Irrigated Corn Field after Inorganic Fertilizer or Manure Application

NASA Astrophysics Data System (ADS)

Lentz, R. D.; Lehrsch, G. A.

2014-12-01

Little is known about inorganic fertilizer or manure effects on organic carbon (OC) and inorganic C (IC) losses from a furrow irrigated field, particularly in the context of other system C gains or losses. In 2003 and 2004, we measured dissolved organic and inorganic C (DOC, DIC), particulate OC and IC (POC, PIC) concentrations in irrigation inflow, runoff, and percolation waters (6-7 irrigations/y); C inputs from soil amendments and crop biomass; harvested C; and gaseous C emissions from field plots cropped to silage corn (Zea mays L.) in southern Idaho. Annual treatments included: (M) 13 (y 1) and 34 Mg/ha (y 2) stockpiled dairy manure; (F) 78 (yr 1) and 195 kg N/ha (y 2) inorganic N fertilizer; or (NA) no amendment--control. The mean annual total C input into M plots averaged 16.1 Mg/ha, 1.4-times greater than that for NA (11.5 Mg/ha) or F (11.1 Mg/ha), while total C outputs for the three treatments were similar, averaging 11.8 Mg/ha. Thus, the manure plots ended each growing season with an average net gain of 3.8 Mg C/ha (a positive net C flux), while the control (-0.5 Mg C/ha) and fertilizer (-0.4 Mg C/ha) treatments finished the season with a net C loss. Atmospheric CO2 incorporated into the crop biomass contributed 96% of the mean annual C input to NA and F plots but only 68% to M plots. We conclude that nutrient amendments substantially influence the short-term carbon balance of our furrow-irrigated system. Amendments had both direct and indirect influences on individual C components, such as the losses of DIC and POC in runoff and DOC in percolation water, producing temporally complex outcomes which may depend on environmental conditions external to the field.

Using raw and sulfur-impregnated activated carbon as active cap for leaching inhibition of mercury and methylmercury from contaminated sediment.

PubMed

Ting, Yu; Chen, Chi; Ch'ng, Boon-Lek; Wang, Ying-Lin; Hsi, Hsing-Cheng

2018-07-15

Sulfur-impregnated activated carbon (SAC) has been reported with a high affinity to Hg, but little research has done on understanding its potential as active cap for inhibition of Hg release from contaminated sediments. In this study, high-quality coconut-shell activated carbon (AC) and its derived SAC were examined and shown to have great affinity to both aqueous Hg 2+ and methylmercury (MeHg). SAC had greater partitioning coefficients for Hg 2+ (K D  = 9.42 × 10 4 ) and MeHg (K D  = 7.661 × 10 5 ) as compared to those for AC (K D  = 3.69 × 10 4 and 2.25 × 10 5 , respectively). However, AC appeared to have greater inhibition in total Hg (THg) leaching from sediment (14.2-235.8 mg-Hg/kg-sediment) to porewater phase as compared to SAC. 3 wt% AC amendment in sediment (235.8 mg/kg Hg) was the optimum dosage causing the porewater THg reduction by 99.88%. Moreover, significant inhibition in both THg and MeHg releases within the 83-d trial microcosm tests was demonstrated with active caps composed of SAC + bentonite, SAC + clean sediment, and AC + bentonite. While both AC and SAC successfully reduce the porewater Hg in sediment environment, the smaller inhibition in Hg release by SAC as compared to that by raw AC may suggest that possibly formed HgS nanoparticles could be released into the porewater that elevates the porewater Hg concentration. Copyright © 2018 Elsevier B.V. All rights reserved.

Soil physical and hydrological properties as affected by long-term addition of various organic amendments

NASA Astrophysics Data System (ADS)

Eden, Marie; Völkel, Jörg; Mercier, Vincent; Labat, Christophe; Houot, Sabine

2014-05-01

The use of organic residues as soil amendments in agriculture not only reduces the amount of waste needing to be disposed of; it may also lead to improvements in soil properties, including physical and hydrological ones. The present study examines a long-term experiment called "Qualiagro", run jointly by INRA and Veolia Environment in Feucherolles, France (near Paris). It was initiated in 1998 on a loess-derived silt loam (787 g/kg silt, 152 g/kg clay) and includes ten treatments: four types of organic amendments and a control (CNT) each at two levels of mineral nitrogen (N) addition: minimal (Nmin) and optimal (Nopt). The amendments include three types of compost and farmyard manure (FYM), which were applied every other year at a rate of ca. 4 t carbon ha-1. The composts include municipal solid waste compost (MSW), co-compost of green wastes and sewage sludge (GWS), and biowaste compost (BIO). The plots are arranged in a randomized block design and have a size of 450 m²; each treatment is replicated four times (total of 40 plots). Ca. 15 years after the start of the experiment soil organic carbon (OC) had continuously increased in the amended plots, while it remained stable or decreased in the control plots. This compost- or manure-induced increase in OC plays a key role, affecting numerous dependant soil properties like bulk density, porosity and water retention. The water holding capacity (WHC) of a soil is of particular interest to farmers in terms of water supply for plants, but also indicates soil quality and functionality. Addition of OC may affect WHC in different ways: carbon-induced aggregation may increase larger-pore volume and hence WHC at the wet end while increased surface areas may lead to an increased retention of water at the dry end. Consequently it is difficult to predict (e.g. with pedotransfer functions) the impact on the amount of water available for plants (PAW), which was experimentally determined for the soils, along with the entire range of the water retention curve. The impact of organic amendments on water retained at field capacity (FC) and wilting point (WP) as well as the retention curve in general differed compared to CNT but also depends on the definition of FC (the associated matric potential). Overall, within the first 15 years of the experiment, the organic treatments affected and generally improved various soil properties relevant in terms of quality, functionality and productivity. Acknowledgment: This work was granted by ADEME within the Pro-Extern project.

Microbial communities involved in methane production from hydrocarbons in oil sands tailings.

PubMed

Siddique, Tariq; Penner, Tara; Klassen, Jonathan; Nesbø, Camilla; Foght, Julia M

2012-09-04

Microbial metabolism of residual hydrocarbons, primarily short-chain n-alkanes and certain monoaromatic hydrocarbons, in oil sands tailings ponds produces large volumes of CH(4) in situ. We characterized the microbial communities involved in methanogenic biodegradation of whole naphtha (a bitumen extraction solvent) and its short-chain n-alkane (C(6)-C(10)) and BTEX (benzene, toluene, ethylbenzene, and xylenes) components using primary enrichment cultures derived from oil sands tailings. Clone libraries of bacterial 16S rRNA genes amplified from these enrichments showed increased proportions of two orders of Bacteria: Clostridiales and Syntrophobacterales, with Desulfotomaculum and Syntrophus/Smithella as the closest named relatives, respectively. In parallel archaeal clone libraries, sequences affiliated with cultivated acetoclastic methanogens (Methanosaetaceae) were enriched in cultures amended with n-alkanes, whereas hydrogenotrophic methanogens (Methanomicrobiales) were enriched with BTEX. Naphtha-amended cultures harbored a blend of these two archaeal communities. The results imply syntrophic oxidation of hydrocarbons in oil sands tailings, with the activities of different carbon flow pathways to CH(4) being influenced by the primary hydrocarbon substrate. These results have implications for predicting greenhouse gas emissions from oil sands tailings repositories.

Sorption-desorption equilibrium and diffusion of tetracycline in poultry litter and municipal biosolids soil amendments.

PubMed

D'Angelo, E

2017-12-01

Tetracycline (TET) is commonly used to treat bacterial diseases in humans and chickens (Gallus gallus domesticus), is largely excreted, and is found at elevated concentrations in treated sewage sludge (biosolids) and poultry litter (excrement plus bedding materials). Routine application of these nutrient-and carbon-enriched materials to soils improves fertility and other characteristics, but the presence of antibiotics (and other pharmaceuticals) in amendments raises questions about potential adverse effects on biota and development of antibiotic resistance in the environment. Hazard risks are largely dictated by sorption-desorption and diffusion behavior in amendments, so these processes were evaluated from sorption-desorption equilibrium isotherm and diffusion cell experiments with four types amendments (biosolids, poultry manure, wood chip litter, and rice hull litter) at three temperatures (8 °C, 20 °C and 32 °C). Linear sorption-desorption equilibrium distribution constants (Kd) in native amendments ranged between 124-2418 L kg -1 . TET sorption was significantly increased after treatment with alum, and there was a strong exponential relationship between Kd and the concentration of bound Al 3+ in amendments (R 2  = 0.94), which indicated that amendments contained functional groups capable of chelating Al 3+ and forming metal bridges with TET. Effective diffusion coefficients of TET in amendments ranged between 0.1 and 5.2 × 10 -6  cm 2  s -1 , which were positively related to temperature and inversely related to Kd by a multiple regression model (R 2  = 0.86). Treatment of organic amendments with alum greatly increased Kd, would decrease D s , and so would greatly reduce hazard risks of applying these organic amendments with this antibiotic to soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

Three-year study of fast-growing trees in degraded soils amended with composts: Effects on soil fertility and productivity.

PubMed

Madejón, Paula; Alaejos, Joaquin; García-Álbala, José; Fernández, Manuel; Madejón, Engracia

2016-03-15

Currently, worries about the effects of intensive plantations on long-term nutrient supply and a loss of productivity have risen. In this study two composts were added to degraded soils where this type of intensive crops were growing, to avoid the soil fertility decrease and try to increase biomass production. For the experiment, two degraded soils in terms of low organic carbon content and low pH were selected in South-West Spain: La Rábida (RA) and Villablanca (VI) sites. Both study sites were divided into 24 plots. In RA, half of the plots were planted with Populus x canadensis "I-214"; the other half was planted with Eucalyptus globulus. At the VI site, half of the plots were planted with Paulownia fortunei, and the other plots were planted with Eucalyptus globulus. For each tree and site, three treatments were established (two organic composts and a control without compost), with four replications per treatment. The organic amendments were "alperujo" compost, AC, a solid by-product from the extraction of olive oil, and BC, biosolid compost. During the three years of experimentation, samples of soils and plants were analyzed for studying chemical and biochemical properties of soil, plant growth and plant nutritional status and biomass production. The composts increased total organic carbon, water-soluble carbon, nutrients and pH of soil only in the most acidic soil. Soil biochemical quality was calculated with the geometric mean of the enzymatic activities (Dehydrogenase, β-glucosidase, Phosphatase and Urease activities) determined in soils. The results showed a beneficial improvement in comparison with soils without compost. However, the best results were found in the growth and biomass production of the studied trees, especially in Eucalyptus. Nutritional levels of leaves of the trees were, in general, in the normal established range for each species, although no clear effect of the composts was observed. The results of this study justify the addition of compost to guarantee good biomass production and maintain or improve soil management in degraded soils, especially in acid soils. Copyright © 2015 Elsevier Ltd. All rights reserved.

Marble waste and pig manure amendments decrease metal availability, increase soil quality and facilitate vegetation development in bare mine soils

NASA Astrophysics Data System (ADS)

Zornoza, Raúl; Faz, Ángel; Martínez-Martínez, Silvia; Acosta, José A.; Gómez, M. Dolores; Ángeles Muñoz, M.

2013-04-01

In order to bring out a functional and sustainable land use in a highly contaminated mine tailing, firstly environmental risks have to be reduced or eliminated by suitable reclamation activities. Tailing ponds pose environmental hazards, such as acidity and toxic metals reaching to waters through wind and water erosions and leaching. As a consequence, soils have no vegetation and low soil organic matter and nutrients. Various physicochemical and biochemical properties, together with exchangeable metals were measured before, 6 months and 12 months after the application of marble waste and pigs manure as reclamation strategy in a tailing pond from SE Spain to reduce hazards for environment and human health. Three months after the last addition of amendments, eight different native shrub species where planted for phytostabilization. Results showed the pH increased up to neutrality. Aggregates stability, organic carbon, total nitrogen, cation exchange capacity, bioavailable phosphorus and potassium, microbial biomass and microbial activity increased with the application of the amendments, while exchangeable metals drastically decreased (~90%). After one year of plantation, only 20% planted species died, with a high growth of survivals reaching flowering and fructification. This study confirms the high effectiveness of initial applications of marble wastes together with pig manure and plantation of shrub species to initialize the recovery of the ecosystem in bare mine soils under Mediterranean semiarid conditions. Key Words: pig manure, marble waste, heavy metals, mine soil. Acknowledgements This work has been funded by the European Union LIFE+ project MIPOLARE (LIFE09 ENV/ES/000439). J.A. Acosta acknowledges a "Saavedra Fajardo" contract from Comunidad Autónoma de Murcia (Spain)

Growth of Norway spruce seedlings after transplanting into silty soil amended with biochar: A bioassay in a growth chamber

Treesearch

J. Heiskanen; P. Tammeorg; R. K. Dumroese

2013-01-01

Biochar (BC), the carbon-rich by-product resulting from pyrolysis of biomass, is used for bioenergy and increasingly as a soil additive for carbon sequestration and soil improvement. However, information about the effects of BC on forest productivity and reforestation success, especially on boreal and temperate forest soils, is scant. We examined the effects of two BC...

The Influence of Leaf Fall and Organic Carbon Availability on Nitrogen Cycling in a Headwater Stream

NASA Astrophysics Data System (ADS)

Thomas, S. A.; Kristin, A.; Doyle, B.; Goodale, C. L.; Gurwick, N. P.; Lepak, J.; Kulkari, M.; McIntyre, P.; McCalley, C.; Raciti, S.; Simkin, S.; Warren, D.; Weiss, M.

2005-05-01

The study of allochthonous carbon has a long and distinguished history in stream ecology. Despite this legacy, relatively little is known regarding the influence of leaf litter on nutrient dynamics. We conducted 15N-NO3 tracer additions to a headwater stream in upstate New York before and after autumn leaf fall to assess the influence of leaf litter on nitrogen spiraling. In addition, we amended the stream with labile dissolved organic carbon (as acetate) midway through each experiment to examine whether organic carbon availability differentially stimulated nitrogen cycling. Leaf standing stocks increased from 53 to 175 g dry mass m-2 and discharge more than tripled (6 to 20 L s-1) between the pre- and post-leaf fall period. In contrast, nitrate concentration fell from approximately 50 to less then 10 ug L-1. Despite higher discharge, uptake length was shorter following leaf fall under both ambient (250 and 72 m, respectively) and DOC amended (125 and 45 m) conditions. Uptake velocity increased dramatically following leaf fall, despite a slight decline in the areal uptake rate. Dissolved N2 gas samples were also collected to estimate denitrification rates under each experimental condition. The temporal extent of increased nitrogen retention will also be explored.

Microbial activities and dissolved organic matter dynamics in oil-contaminated surface seawater from the Deepwater Horizon oil spill site.

PubMed

Ziervogel, Kai; McKay, Luke; Rhodes, Benjamin; Osburn, Christopher L; Dickson-Brown, Jennifer; Arnosti, Carol; Teske, Andreas

2012-01-01

The Deepwater Horizon oil spill triggered a complex cascade of microbial responses that reshaped the dynamics of heterotrophic carbon degradation and the turnover of dissolved organic carbon (DOC) in oil contaminated waters. Our results from 21-day laboratory incubations in rotating glass bottles (roller bottles) demonstrate that microbial dynamics and carbon flux in oil-contaminated surface water sampled near the spill site two weeks after the onset of the blowout were greatly affected by activities of microbes associated with macroscopic oil aggregates. Roller bottles with oil-amended water showed rapid formation of oil aggregates that were similar in size and appearance compared to oil aggregates observed in surface waters near the spill site. Oil aggregates that formed in roller bottles were densely colonized by heterotrophic bacteria, exhibiting high rates of enzymatic activity (lipase hydrolysis) indicative of oil degradation. Ambient waters surrounding aggregates also showed enhanced microbial activities not directly associated with primary oil-degradation (β-glucosidase; peptidase), as well as a twofold increase in DOC. Concurrent changes in fluorescence properties of colored dissolved organic matter (CDOM) suggest an increase in oil-derived, aromatic hydrocarbons in the DOC pool. Thus our data indicate that oil aggregates mediate, by two distinct mechanisms, the transfer of hydrocarbons to the deep sea: a microbially-derived flux of oil-derived DOC from sinking oil aggregates into the ambient water column, and rapid sedimentation of the oil aggregates themselves, serving as vehicles for oily particulate matter as well as oil aggregate-associated microbial communities.

Microbial Activities and Dissolved Organic Matter Dynamics in Oil-Contaminated Surface Seawater from the Deepwater Horizon Oil Spill Site

PubMed Central

Ziervogel, Kai; McKay, Luke; Rhodes, Benjamin; Osburn, Christopher L.; Dickson-Brown, Jennifer; Arnosti, Carol; Teske, Andreas

2012-01-01

The Deepwater Horizon oil spill triggered a complex cascade of microbial responses that reshaped the dynamics of heterotrophic carbon degradation and the turnover of dissolved organic carbon (DOC) in oil contaminated waters. Our results from 21-day laboratory incubations in rotating glass bottles (roller bottles) demonstrate that microbial dynamics and carbon flux in oil-contaminated surface water sampled near the spill site two weeks after the onset of the blowout were greatly affected by activities of microbes associated with macroscopic oil aggregates. Roller bottles with oil-amended water showed rapid formation of oil aggregates that were similar in size and appearance compared to oil aggregates observed in surface waters near the spill site. Oil aggregates that formed in roller bottles were densely colonized by heterotrophic bacteria, exhibiting high rates of enzymatic activity (lipase hydrolysis) indicative of oil degradation. Ambient waters surrounding aggregates also showed enhanced microbial activities not directly associated with primary oil-degradation (β-glucosidase; peptidase), as well as a twofold increase in DOC. Concurrent changes in fluorescence properties of colored dissolved organic matter (CDOM) suggest an increase in oil-derived, aromatic hydrocarbons in the DOC pool. Thus our data indicate that oil aggregates mediate, by two distinct mechanisms, the transfer of hydrocarbons to the deep sea: a microbially-derived flux of oil-derived DOC from sinking oil aggregates into the ambient water column, and rapid sedimentation of the oil aggregates themselves, serving as vehicles for oily particulate matter as well as oil aggregate-associated microbial communities. PMID:22509359

Department of Energy Carbon Capture and Sequestration Program Amendments Act of 2011

THOMAS, 112th Congress

Sen. Bingaman, Jeff [D-NM

2011-03-31

Senate - 07/11/2011 Placed on Senate Legislative Calendar under General Orders. Calendar No. 99. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Sustainable biochar effects for low carbon crop production: A 5-crop season field experiment on a low fertility soil from Central China

NASA Astrophysics Data System (ADS)

Liu, X.

2014-12-01

Biochar's effects on improving soil fertility, enhancing crop productivity and reducing greenhouse gases (GHGs) emission from croplands had been well addressed in numerous short-term experiments with biochar soil amendment (BSA) mostly in a single crop season / cropping year. However, the persistence of these effects, after a single biochar application, has not yet been well known due to limited long-term field studies so far. Large scale BSA in agriculture is often commented on the high cost due to large amount of biochar in a single application. Here, we try to show the persistence of biochar effects on soil fertility and crop productivity improvement as well as GHGs emission reduction, using data from a field experiment with BSA for 5 crop seasons in central North China. A single amendment of biochar was performed at rates of 0 (C0), 20 (C20) and 40 t ha-1 (C40) before sowing of the first crop season. Emissions of CO2, CH4 and N2O were monitored with static closed chamber method throughout the crop growing season for the 1st, 2nd and 5th cropping. Crop yield was measured and topsoil samples were collected at harvest of each crop season. BSA altered most of the soil physic-chemical properties with a significant increase over control in soil organic carbon (SOC) and available potassium (K) content. The increase in SOC and available K was consistent over the 5 crop seasons after BSA. Despite a significant yield increase in the first maize season, enhancement of crop yield was not consistent over crop seasons without corresponding to the changes in soil nutrient availability. BSA did not change seasonal total CO2 efflux but greatly reduced N2O emissions throughout the five seasons. This supported a stable nature of biochar carbon in soil, which played a consistent role in reducing N2O emission, which showed inter-annual variation with changes in temperature and soil moisture conditions. The biochar effect was much more consistent under C40 than under C20 and with GHGs emission than with soil property and crop yield. Thus, our study suggested that biochar amended in dry land could sustain a low carbon production both of maize and wheat in terms of its efficient carbon sequestration, lower GHGs emission intensity and soil improvement over 5 crop seasons after a single amendment.

Substrate-Driven Convergence of the Microbial Community in Lignocellulose-Amended Enrichments of Gut Microflora from the Canadian Beaver (Castor canadensis) and North American Moose (Alces americanus).

PubMed

Wong, Mabel T; Wang, Weijun; Lacourt, Michael; Couturier, Marie; Edwards, Elizabeth A; Master, Emma R

2016-01-01

Strategic enrichment of microcosms derived from wood foragers can facilitate the discovery of key microbes that produce enzymes for the bioconversion of plant fiber (i.e., lignocellulose) into valuable chemicals and energy. In this study, lignocellulose-degrading microorganisms from the digestive systems of Canadian beaver (Castor canadensis) and North American moose (Alces americanus) were enriched under methanogenic conditions for over 3 years using various wood-derived substrates, including (i) cellulose (C), (ii) cellulose + lignosulphonate (CL), (iii) cellulose + tannic acid (CT), and (iv) poplar hydrolysate (PH). Substantial improvement in the conversion of amended organic substrates into biogas was observed in both beaver dropping and moose rumen enrichment cultures over the enrichment phases (up to 0.36-0.68 ml biogas/mg COD added), except for enrichments amended with tannic acid where conversion was approximately 0.15 ml biogas/mg COD added. Multiplex-pyrosequencing of 16S rRNA genes revealed systematic shifts in the population of Firmicutes, Bacteroidetes, Chlorobi, Spirochaetes, Chloroflexi, and Elusimicrobia in response to the enrichment. These shifts were predominantly substrate driven, not inoculum driven, as revealed by both UPGMA clustering pattern and OTU distribution. Additionally, the relative abundance of multiple OTUs from poorly defined taxonomic lineages increased from less than 1% to 25-50% in microcosms amended with lignocellulosic substrates, including OTUs from classes SJA-28, Endomicrobia, orders Bacteroidales, OPB54, and family Lachnospiraceae. This study provides the first direct comparison of shifts in microbial communities that occurred in different environmental samples in response to multiple relevant lignocellulosic carbon sources, and demonstrates the potential of enrichment to increase the abundance of key lignocellulolytic microorganisms and encoded activities.

Substrate-Driven Convergence of the Microbial Community in Lignocellulose-Amended Enrichments of Gut Microflora from the Canadian Beaver (Castor canadensis) and North American Moose (Alces americanus)

PubMed Central

Wong, Mabel T.; Wang, Weijun; Lacourt, Michael; Couturier, Marie; Edwards, Elizabeth A.; Master, Emma R.

2016-01-01

Strategic enrichment of microcosms derived from wood foragers can facilitate the discovery of key microbes that produce enzymes for the bioconversion of plant fiber (i.e., lignocellulose) into valuable chemicals and energy. In this study, lignocellulose-degrading microorganisms from the digestive systems of Canadian beaver (Castor canadensis) and North American moose (Alces americanus) were enriched under methanogenic conditions for over 3 years using various wood-derived substrates, including (i) cellulose (C), (ii) cellulose + lignosulphonate (CL), (iii) cellulose + tannic acid (CT), and (iv) poplar hydrolysate (PH). Substantial improvement in the conversion of amended organic substrates into biogas was observed in both beaver dropping and moose rumen enrichment cultures over the enrichment phases (up to 0.36–0.68 ml biogas/mg COD added), except for enrichments amended with tannic acid where conversion was approximately 0.15 ml biogas/mg COD added. Multiplex-pyrosequencing of 16S rRNA genes revealed systematic shifts in the population of Firmicutes, Bacteroidetes, Chlorobi, Spirochaetes, Chloroflexi, and Elusimicrobia in response to the enrichment. These shifts were predominantly substrate driven, not inoculum driven, as revealed by both UPGMA clustering pattern and OTU distribution. Additionally, the relative abundance of multiple OTUs from poorly defined taxonomic lineages increased from less than 1% to 25–50% in microcosms amended with lignocellulosic substrates, including OTUs from classes SJA-28, Endomicrobia, orders Bacteroidales, OPB54, and family Lachnospiraceae. This study provides the first direct comparison of shifts in microbial communities that occurred in different environmental samples in response to multiple relevant lignocellulosic carbon sources, and demonstrates the potential of enrichment to increase the abundance of key lignocellulolytic microorganisms and encoded activities. PMID:27446004

Part 106--Nondiscrimination on the Basis of Sex in Education Programs or Activities Receiving Federal Financial Assistance.

ERIC Educational Resources Information Center

Office for Civil Rights (ED), Washington, DC.

This document addresses nondiscrimination on the basis of sex in education programs or activities receiving federal financial assistance. It includes the amendments made in the notice of Final Regulations published in the Federal Register on November 13, 2000. The amendments effectuate Title IX of the Education Amendments of 1972. The official…

Molecular Assessment of litter decay dynamics across old and young forest sites

NASA Astrophysics Data System (ADS)

Filley, T. R.; Crow, S.; Gamblin, D.; McCormick, M.; Whigham, D.; Taylor, D. L.

2006-12-01

The response of soil organic matter pools to changes in litter input, land cover, and ýinvertebrate activity is a research area of intensive study given the proposed impacts that ýrising CO2 and surface temperatures may have on forest productivity and distribution of ýinvasive species. In a mixed deciduous forest at the Smithsonian Environmental ýResearch Center litter amendment plots were established in old (120-150 y) and young ýý(50-70 y) forests. In May 2004, six plots were amended with locally collected ýLirodendron tulipifera wood (chipped) and leaves. At the same time, leaf and wood litter ýbag decomposition experiments on the sites were also started. Changes in the ýconcentration and composition of biopolymers, e.g. lignin and cutin/suberin, after ýapproximately four months of decay were tracked by alkaline CuO extraction. Resultant ýleaf and wood litter in the surface amendments was distinct between age groupings. ýYoung sites exhibited the greatest change in chemical character showing increased lignin ýand decreased cutin/suberin resulting in a cutin-poor residue. Minor changes to ýbiopolymer character were observed in older sites with residues exhibiting small but ýopposite trends to the young sites. In contrast, the litter bag studies exhibited little to no ývariation in chemistry with age of stand; although, generally leaf litter showed the ýgreatest age-related effect. These patterns in litter decay are consistent with both ýmicrobial activity and relative biomass of invasive earthworms; young forests exhibit ýrelatively higher activity of both phenol oxidase and B-glucosidase in the soil (0-5 cm) ýplots and greater biomass and relative abundance invasive earthworms. These results are ýimportant as they show how stand age and the presence of invertebrate species may have ýimportant controls on the impact that many global change drivers may have on forest soil ýand carbon exchange dynamics.ý

Arsenic and selenium mobilisation from organic matter treated mine spoil with and without inorganic fertilisation.

PubMed

Moreno-Jiménez, Eduardo; Clemente, Rafael; Mestrot, Adrien; Meharg, Andrew A

2013-02-01

Organic matter amendments are applied to contaminated soil to provide a better habitat for re-vegetation and remediation, and olive mill waste compost (OMWC) has been described as a promising material for this aim. We report here the results of an incubation experiment carried out in flooded conditions to study its influence in As and metal solubility in a trace elements contaminated soil. NPK fertilisation and especially organic amendment application resulted in increased As, Se and Cu concentrations in pore water. Independent of the amendment, dimethylarsenic acid (DMA) was the most abundant As species in solution. The application of OMWC increased pore water dissolved organic-carbon (DOC) concentrations, which may explain the observed mobilisation of As, Cu and Se; phosphate added in NPK could also be in part responsible of the mobilisation caused in As. Therefore, the application of soil amendments in mine soils may be particularly problematic in flooded systems. Copyright © 2012 Elsevier Ltd. All rights reserved.

Impact of organosulfur content on diesel fuel stability and implications for carbon steel corrosion.

PubMed

Lyles, Christopher N; Aktas, Deniz F; Duncan, Kathleen E; Callaghan, Amy V; Stevenson, Bradley S; Suflita, Joseph M

2013-06-04

Ultralow sulfur diesel (ULSD) fuel has been integrated into the worldwide fuel infrastructure to help meet a variety of environmental regulations. However, desulfurization alters the properties of diesel fuel in ways that could potentially impact its biological stability. Fuel desulfurization might predispose ULSD to biodeterioration relative to sulfur-rich fuels and in marine systems accelerate rates of sulfate reduction, sulfide production, and carbon steel biocorrosion. To test such prospects, an inoculum from a seawater-compensated ballast tank was amended with fuel from the same ship or with refinery fractions of ULSD, low- (LSD), and high sulfur diesel (HSD) and monitored for sulfate depletion. The rates of sulfate removal in incubations amended with the refinery fuels were elevated relative to the fuel-unamended controls but statistically indistinguishable (∼50 μM SO4/day), but they were found to be roughly twice as fast (∼100 μM SO4/day) when the ship's own diesel was used as a source of carbon and energy. Thus, anaerobic hydrocarbon metabolism likely occurred in these incubations regardless of fuel sulfur content. Microbial community structure from each incubation was also largely independent of the fuel amendment type, based on molecular analysis of 16S rRNA sequences. Two other inocula known to catalyze anaerobic hydrocarbon metabolism showed no differences in fuel-associated sulfate reduction or methanogenesis rates between ULSD, LSD, and HSD. These findings suggest that the stability of diesel is independent of the fuel organosulfur compound status and reasons for the accelerated biocorrosion associated with the use of ULSD should be sought elsewhere.

Selective enrichment of a methanol-utilizing consortium using pulp & paper mill waste streams

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

Gregory R. Mockos; William A. Smith; Frank J. Loge

Efficient utilization of carbon inputs is critical to the economic viability of the current forest products sector. Input carbon losses occur in various locations within a pulp mill, including losses as volatile organics and wastewater . Opportunities exist to capture this carbon in the form of value-added products such as biodegradable polymers. Waste activated sludge from a pulp mill wastewater facility was enriched for 80 days for a methanol-utilizing consortium with the goal of using this consortium to produce biopolymers from methanol-rich pulp mill waste streams. Five enrichment conditions were utilized: three high-methanol streams from the kraft mill foul condensatemore » system, one methanol-amended stream from the mill wastewater plant, and one methanol-only enrichment. Enrichment reactors were operated aerobically in sequencing batch mode at neutral pH and 25°C with a hydraulic residence time and a solids retention time of four days. Non-enriched waste activated sludge did not consume methanol or reduce chemical oxygen demand. With enrichment, however, the chemical oxygen demand reduction over 24 hour feed/decant cycles ranged from 79 to 89 %, and methanol concentrations dropped below method detection limits. Neither the non-enriched waste activated sludge nor any of the enrichment cultures accumulated polyhydroxyalkanoates (PHAs) under conditions of nitrogen sufficiency. Similarly, the non-enriched waste activated sludge did not accumulate PHAs under nitrogen limited conditions. By contrast, enriched cultures accumulated PHAs to nearly 14% on a dry weight basis under nitrogen limited conditions. This indicates that selectively-enriched pulp mill waste activated sludge can serve as an inoculum for PHA production from methanol-rich pulp mill effluents.« less

Natural oil slicks fuel surface water microbial activities in the northern Gulf of Mexico

PubMed Central

Ziervogel, Kai; D'souza, Nigel; Sweet, Julia; Yan, Beizhan; Passow, Uta

2014-01-01

We conducted a series of roller tank incubations with surface seawater from the Green Canyon oil reservoir, northern Gulf of Mexico, amended with either a natural oil slick (GCS-oil) or pristine oil. The goal was to test whether bacterial activities of natural surface water communities facilitate the formation of oil-rich marine snow (oil snow). Although oil snow did not form during any of our experiments, we found specific bacterial metabolic responses to the addition of GCS-oil that profoundly affected carbon cycling within our 4-days incubations. Peptidase and β-glucosidase activities indicative of bacterial enzymatic hydrolysis of peptides and carbohydrates, respectively, were suppressed upon the addition of GCS-oil relative to the non-oil treatment, suggesting that ascending oil and gas initially inhibits bacterial metabolism in surface water. Biodegradation of physically dispersed GCS-oil components, indicated by the degradation of lower molecular weight n-alkanes as well as the rapid transformation of particulate oil-carbon (C: N >40) into the DOC pool, led to the production of carbohydrate- and peptide-rich degradation byproducts and bacterial metabolites such as transparent exopolymer particles (TEP). TEP formation was highest at day 4 in the presence of GCS-oil; in contrast, TEP levels in the non-oil treatment already peaked at day 2. Cell-specific enzymatic activities closely followed TEP concentrations in the presence and absence of GCS-oil. These results demonstrate that the formation of oil slicks and activities of oil-degrading bacteria result in a temporal offset of microbial cycling of organic matter, affecting food web interactions and carbon cycling in surface waters over cold seeps. PMID:24847314

Natural oil slicks fuel surface water microbial activities in the northern Gulf of Mexico.

PubMed

Ziervogel, Kai; D'Souza, Nigel; Sweet, Julia; Yan, Beizhan; Passow, Uta

2014-01-01

We conducted a series of roller tank incubations with surface seawater from the Green Canyon oil reservoir, northern Gulf of Mexico, amended with either a natural oil slick (GCS-oil) or pristine oil. The goal was to test whether bacterial activities of natural surface water communities facilitate the formation of oil-rich marine snow (oil snow). Although oil snow did not form during any of our experiments, we found specific bacterial metabolic responses to the addition of GCS-oil that profoundly affected carbon cycling within our 4-days incubations. Peptidase and β-glucosidase activities indicative of bacterial enzymatic hydrolysis of peptides and carbohydrates, respectively, were suppressed upon the addition of GCS-oil relative to the non-oil treatment, suggesting that ascending oil and gas initially inhibits bacterial metabolism in surface water. Biodegradation of physically dispersed GCS-oil components, indicated by the degradation of lower molecular weight n-alkanes as well as the rapid transformation of particulate oil-carbon (C: N >40) into the DOC pool, led to the production of carbohydrate- and peptide-rich degradation byproducts and bacterial metabolites such as transparent exopolymer particles (TEP). TEP formation was highest at day 4 in the presence of GCS-oil; in contrast, TEP levels in the non-oil treatment already peaked at day 2. Cell-specific enzymatic activities closely followed TEP concentrations in the presence and absence of GCS-oil. These results demonstrate that the formation of oil slicks and activities of oil-degrading bacteria result in a temporal offset of microbial cycling of organic matter, affecting food web interactions and carbon cycling in surface waters over cold seeps.

Formate oxidation-driven calcium carbonate precipitation by Methylocystis parvus OBBP.

PubMed

Ganendra, Giovanni; De Muynck, Willem; Ho, Adrian; Arvaniti, Eleni Charalampous; Hosseinkhani, Baharak; Ramos, Jose Angel; Rahier, Hubert; Boon, Nico

2014-08-01

Microbially induced carbonate precipitation (MICP) applied in the construction industry poses several disadvantages such asammonia release to the air and nitric acid production. An alternative MICP from calcium formate by Methylocystis parvus OBBP is presented here to overcome these disadvantages. To induce calcium carbonate precipitation, M. parvus was incubated at different calcium formate concentrations and starting culture densities. Up to 91.4% ± 1.6% of the initial calcium was precipitated in the methane-amended cultures compared to 35.1% ± 11.9% when methane was not added. Because the bacteria could only utilize methane for growth, higher culture densities and subsequently calcium removals were exhibited in the cultures when methane was added. A higher calcium carbonate precipitate yield was obtained when higher culture densities were used but not necessarily when more calcium formate was added. This was mainly due to salt inhibition of the bacterial activity at a high calcium formate concentration. A maximum 0.67 ± 0.03 g of CaCO3 g of Ca(CHOOH)2(-1) calcium carbonate precipitate yield was obtained when a culture of 10(9) cells ml(-1) and 5 g of calcium formate liter(-)1 were used. Compared to the current strategy employing biogenic urea degradation as the basis for MICP, our approach presents significant improvements in the environmental sustainability of the application in the construction industry.

Formate Oxidation-Driven Calcium Carbonate Precipitation by Methylocystis parvus OBBP

PubMed Central

Ganendra, Giovanni; De Muynck, Willem; Ho, Adrian; Arvaniti, Eleni Charalampous; Hosseinkhani, Baharak; Ramos, Jose Angel; Rahier, Hubert

2014-01-01

Microbially induced carbonate precipitation (MICP) applied in the construction industry poses several disadvantages such as ammonia release to the air and nitric acid production. An alternative MICP from calcium formate by Methylocystis parvus OBBP is presented here to overcome these disadvantages. To induce calcium carbonate precipitation, M. parvus was incubated at different calcium formate concentrations and starting culture densities. Up to 91.4% ± 1.6% of the initial calcium was precipitated in the methane-amended cultures compared to 35.1% ± 11.9% when methane was not added. Because the bacteria could only utilize methane for growth, higher culture densities and subsequently calcium removals were exhibited in the cultures when methane was added. A higher calcium carbonate precipitate yield was obtained when higher culture densities were used but not necessarily when more calcium formate was added. This was mainly due to salt inhibition of the bacterial activity at a high calcium formate concentration. A maximum 0.67 ± 0.03 g of CaCO3 g of Ca(CHOOH)2−1 calcium carbonate precipitate yield was obtained when a culture of 109 cells ml−1 and 5 g of calcium formate liter−1 were used. Compared to the current strategy employing biogenic urea degradation as the basis for MICP, our approach presents significant improvements in the environmental sustainability of the application in the construction industry. PMID:24837386

75 FR 75663 - Certain Coated Paper Suitable for High-Quality Print Graphics Using Sheet-Fed Presses From the...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-06

...., Washington, DC 20230. SUPPLEMENTARY INFORMATION: On November 17, 2010, the Department published an amended... (China or other clay), calcium carbonate, titanium dioxide, and/or other inorganic substances; with or...

Investigating biochar as a tool for environmental remediation

EPA Science Inventory

Biochar is being proposed as a cost-effective, carbon negative soil amendment for environmental remediation. Research has demonstrated the efficacy of biochar to sorb heavy metals and agricultural chemicals from contaminated soils, thus effectively reducing the potential for met...

Department of Energy Carbon Capture and Sequestration Program Amendments Act of 2009

THOMAS, 111th Congress

Sen. Bingaman, Jeff [D-NM

2009-05-07

Senate - 05/14/2009 Committee on Energy and Natural Resources. Hearings held. Hearings printed: S.Hrg. 111-50. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Synthesis of biomass derived carbon materials for environmental engineering and energy storage applications

NASA Astrophysics Data System (ADS)

Huggins, Mitchell Tyler

Biomass derived carbon (BC) can serve as an environmentally and cost effective material for both remediation and energy production/storage applications. The use of locally derived biomass, such as unrefined wood waste, provides a renewable feedstock for carbon material production compared to conventional unrenewable resources like coal. Additionally, energy and capital cost can be reduced through the reduction in transport and processing steps and the use of spent material as a soil amendment. However, little work has been done to evaluate and compare biochar to conventional materials such as granular activated carbon or graphite in advanced applications of Environmental Engineering. In this work I evaluated the synthesis and compared the performance of biochar for different applications in wastewater treatment, nutrient recovery, and energy production and storage. This includes the use of biochar as an electrode and filter media in several bioelectrochemical systems (BES) treating synthetic and industrial wastewater. I also compared the treatment efficiency of granular biochar as a packed bed adsorbent for the primary treatment of high strength brewery wastewater. My studies conclude with the cultivation of fungal biomass to serve as a template for biochar synthesis, controlling the chemical and physical features of the feedstock and avoiding some of the limitations of waste derived materials.

Impacts of integrated nutrient management on methane emission, global warming potential and carbon storage capacity in rice grown in a northeast India soil.

PubMed

Bharali, Ashmita; Baruah, Kushal Kumar; Baruah, Sunitee Gohain; Bhattacharyya, Pradip

2018-02-01

Rice soil is a source of emission of two major greenhouse gases (methane (CH 4 ) and nitrous oxide (N 2 O)) and a sink of carbon dioxide (CO 2 ). The effect of inorganic fertilizers in combination with various organics (cow dung, green manure (Sesbania aculeata) Azolla compost, rice husk) on CH 4 emission, global warming potential, and soil carbon storage along with crop productivity were studied at university farm under field conditions. The experiment was conducted in a randomized block design for 2 years in a monsoon rice (cv. Ranjit) ecosystem (June-November, 2014 and 2015). Combined application of inorganic (NPK) with Sesbania aculeata resulted in high global warming potential (GWP) of 887.4 kg CO 2 ha -1 and low GWP of 540.6 kg CO 2 ha -1 was recorded from inorganic fertilizer applied field. Irrespective of the type of organic amendments, flag leaf photosynthesis of the rice crop increased over NPK application (control). There was an increase in CH 4 emission from the organic amended fields compared to NPK alone. The combined application of NPK and Azolla compost was effective in the buildup of soil carbon (16.93 g kg -1 ) and capacity of soil carbon storage (28.1 Mg C ha -1 ) with high carbon efficiency ratio (16.9). Azolla compost application along with NPK recorded 15.66% higher CH 4 emission with 27.43% yield increment over control. Azolla compost application significantly enhanced carbon storage of soil and improved the yielding ability of grain (6.55 Mg ha -1 ) over other treatments.

Effect of nitrate, organic carbon, and temperature on potential denitrification rates in nitrate-rich riverbed sediments

USGS Publications Warehouse

Pfenning, K.S.; McMahon, P.B.

1997-01-01

A study conducted in 1994 as part of the US Geological Survey's National Water-Quality Assessment Program, South Platte River Basin investigation, examined the effect of certain environmental factors on potential denitrification rates in nitrate-rich riverbed sediments. The acetylene block technique was used to measure nitrous oxide (N2O) production rates in laboratory incubations of riverbed sediments to evaluate the effect of varying nitrate concentrations, organic carbon concentrations and type, and water temperature on potential denitrification rates. Sediment incubations amended with nitrate, at concentrations ranging from 357 to 2142 ??mol l-1 (as measured in the field), produced no significant increase (P > 0.05) in N2O production rates, indicating that the denitrification potential in these sediments was not nitrate limited. In contrast, incubations amended with acetate as a source of organic carbon, at concentrations ranging from 0 to 624 ??mol l-1, produced significant increases (P < 0.05) in N2O production rates with increased organic carbon concentration, indicating that the denitrification potential in these sediments was organic carbon limited. Furthermore, N2O production rates also were affected by the type of organic carbon available as an electron donor. Acetate and surface-water-derived fulvic acid supported higher N2O production rates than groundwater-derived fulvic acid or sedimentary organic carbon. Lowering incubation temperatures from 22 to 4??C resulted in about a 77% decrease in the N2O production rates. These results help to explain findings from previous studies indicating that only 15-30% of nitrate in groundwater was denitrified before discharging to the South Platte River and that nitrate concentrations in the river generally were higher in winter than in summer.

77 FR 30376 - Amendment of Restricted Area R-2101; Anniston Army Depot, AL

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-23

...-0510; Airspace Docket No. 12-ASO-17] RIN 2120-AA66 Amendment of Restricted Area R-2101; Anniston Army... amends the description of restricted area R-2101, Anniston Army Depot, AL, by removing the abbreviation.... This amendment does not change the dimensions of, or activities conducted within, R-2101. DATES...

An assessment of emergy, energy, and cost-benefits of grain production over 6 years following a biochar amendment in a rice paddy from China.

PubMed

Wang, Lei; Li, Lianqing; Cheng, Kun; Ji, Chunying; Yue, Qian; Bian, Rongjun; Pan, Genxing

2018-04-01

Biochar soil amendment had been increasingly advocated for improving crop productivity and reducing carbon footprint in agriculture worldwide. However, the long-term benefits of biochar application with farming systems had not been thoroughly understood. This study quantified and assessed emergy, energy, and economic benefits of rice and wheat production throughout 6 rotation years following a single biochar amendment in a rice paddy from Southeastern China. Using the data from farm inventory, the quantified emergy indices included grain outputs, unit emergy value, and relative percentage of free renewable resources, environmental loading ratio, emergy yield ratio, and emergy sustainability index (ESI). The results indicated contrasting differences in these emergy values between biochar-amended and unamended production systems over the 6 years. The overall emergy efficiency of rice and wheat productions in biochar-amended system were higher by 11-28 and 15-47%, respectively, than that of unamended one of which the production being highly resource intensive. Moreover, ESI on average was 0.46 for rice and 0.63 for wheat in amended system, compared to 0.35 for rice and 0.39 for wheat in unamended one. Furthermore, over the 6 years following a single application, the ESI values showed considerable variation in the unamended system but consistently increasing in the amended system. Again, the biochar-amended system exerted significantly higher energy and economic return than the unamended one. Nonetheless, there was a tradeoff between rice and wheat in grain yield and net economic gain. Overall, biochar amendment could be a viable measure to improve the resilience of grain production while to reduce resource intensity and environment impacts in paddy soil from China.

Influence of calcium carbonate and charcoal application on aggregation processes and organic matter retention at the silt-size scale

NASA Astrophysics Data System (ADS)

Asefaw Berhe, Asmeret; Kaiser, Michael; Ghezzehei, Teamrat; Myrold, David; Kleber, Markus

2013-04-01

The effectiveness of charcoal and calcium carbonate applications to improve soil conditions has been well documented. However, their influence on the formation of silt-sized aggregates and the amount and protection of associated organic matter (OM) against microbial decomposition is still largely unknown. For sustainable management of agricultural soils, silt-sized aggregates (2-53 µm) are of particularly large importance because they store up to 60% of soil organic carbon with mean residence times between 70 and 400 years. The objectives are i) to analyze the ability of CaCO3 and/or charcoal application to increase the amount of silt-sized aggregates and associated OM, ii) vary soil mineral conditions to establish relevant boundary conditions for amendment-induced aggregation processes, iii) to determine how amendment-induced changes in formation of silt-sized aggregates relate to microbial decomposition of OM. We set up artificial high reactive (HR, clay: 40%, sand: 57%, OM: 3%) and low reactive soils (LR, clay: 10%, sand: 89%, OM: 1%) and mixed them with charcoal (CC, 1%) and/or calcium carbonate (Ca, 0.2%). The samples were adjusted to a water potential of 0.3 bar and sub samples were incubated with microbial inoculum (MO). After a 16-weeks aggregation experiment, size fractions were separated by wet-sieving and sedimentation. Since we did not use mineral compounds in the artificial mixtures within the size range of 2 to 53 µm, we consider material recovered in this fraction as silt-sized aggregates, which was confirmed by SEM analyses. For the LR mixtures, we detected increasing N concentrations within the 2-53 µm fractions of the charcoal amended samples (CC, CC+Ca, and CC+Ca+MO) as compared to the Control sample with the strongest effect for the CC+Ca+MO sample. This indicates an association of N-containing microbial derived OM with silt-sized aggregates. For the charcoal amended LR and HR mixtures, the C concentrations of the 2-53 µm fractions are larger than those of the respective fractions of the Control samples but the effect is several times stronger for the LR mixtures. The C concentrations of the 2-53 µm fractions relative to the total C amount of the LR and HR mixtures are between 30 and 50%. The charcoal amended samples show generally larger relative C amounts associated with the 2-53 µm fractions than the Control samples. Benefits for aggregate formation and OM storage were larger for sand (LR) than for clay soil (HR). The gained data are similar to respective data for natural soils. Consequently, the suggested microcosm experiments are suitable to analyze mechanisms within soil aggregation processes.

Author Correction: The carbon footprint of global tourism

NASA Astrophysics Data System (ADS)

Lenzen, Manfred; Sun, Ya-Yen; Faturay, Futu; Ting, Yuan-Peng; Geschke, Arne; Malik, Arunima

2018-06-01

In the version of this Article originally published, in the penultimate paragraph of the section "Gas species and supply chains", in the sentence "In this assessment, the contribution of air travel emissions amounts to 20% (0.9 GtCO2e) of tourism's global carbon footprint..." the values should have read "12% (0.55 GtCO2e)"; this error has now been corrected, and Supplementary Table 9 has been amended to clarify this change.

Changes in heavy metal bioavailability and speciation from a Pb-Zn mining soil amended with biochars from co-pyrolysis of rice straw and swine manure.

PubMed

Meng, Jun; Tao, Mengming; Wang, Lili; Liu, Xingmei; Xu, Jianming

2018-08-15

Biochar has been utilized as a good amendment to immobilize heavy metals in contaminated soils. However, the effectiveness of biochar in metal immobilization depends on biochar properties and metal species. In this study, the biochars produced from co-pyrolysis of rice straw with swine manure at 400°C were investigated to evaluate their effects on bioavailability and chemical speciation of four heavy metals (Cd, Cu, Pb and Zn) in a Pb-Zn contaminated soil through incubation experiment. Results showed that co-pyrolysis process significantly change the yield, ash content, pH, and electrical conductivity (EC) of the blended biochars compared with the single straw/manure biochar. The addition of these biochars significantly increased the soil pH, EC, and dissolved organic carbon (DOC) concentrations. The addition of biochars at a rate of 3% significantly reduced the CaCl 2 -extractable metal concentrations in the order of Pb>Cu>Zn>Cd. The exchangeable heavy metals decreased in all the biochar-amended soils whereas the carbonate-bound metal speciation increased. The increase in soil pH and the decrease in the CaCl 2 extractable metals indicated that these amendments can directly transform the highly availability metal speciation to the stable speciation in soils. In conclusion, biochar derived from co-pyrolysis of rice straw with swine manure at a mass ratio of 3:1 could most effectively immobilize the heavy metals in the soil. Copyright © 2018 Elsevier B.V. All rights reserved.

Global Warming Potential from early phase decomposition of soil organic matter amendments

NASA Astrophysics Data System (ADS)

Mayer, A.; Silver, W. L.

2015-12-01

Organic matter amendments to soil are widely used as a method of enhancing nutrient availability for crops or grassland. Amendments such as composted manure or greenwaste also have the co-benefits of potentially increasing soil carbon (C) stocks (DeLonge et al., 2013) and diverting organic waste from landfills or manure lagoons. However, application of organic matter amendments can also stimulate emissions of greenhouse gases (GHGs). In this study we determined how the chemical quality of organic matter amendments affected soil C and N content and GHG emissions during early stage decomposition. California grassland soils were amended with six different amendments of varying C and N content including three composts and three feedstocks (goat and horse bedding and cattle manure). Amendments and soils were incubated in the laboratory for 7 weeks; GHG fluxes were measured weekly. The three feedstocks emitted significantly more GHGs than the composted materials. With the exception of cow manure, N content of the amendment was linearly correlated with global warming potential emitted (R2= 0.66, P <0.0001). C:N ratios were not a significant predictor of GHG emissions. Cow manure stimulated a net loss of C (or C equivalents) in the mineral soil, as expected. However, greenwaste compost also surprisingly resulted in net C losses, while goat bedding, horse bedding, and the other compost were either C neutral or a slight net C sink at the end of the incubation. Ongoing analyses are examining the fate of the C incorporated from the amendment to the soil as occluded or free light fraction, as well as N mineralization rates. Our data suggest that N content of organic matter amendments is a good predictor of initial GHG emissions. The study also indicates that composting greenwaste with N-rich bedding and manure can result in lower GHG emissions and C sequestration compared to the individual uncomposted components.

Microbial association with the dynamics of particulate organic carbon in response to the amendment of elevated CO2-derived wheat residue into a Mollisol.

PubMed

Wang, Yanhong; Yu, Zhenhua; Li, Yansheng; Wang, Guanghua; Liu, Junjie; Liu, Judong; Liu, Xiaobing; Jin, Jian

2017-12-31

As the chemical quality of crop residue is likely to be affected by elevated CO 2 (eCO 2 ), residue amendments may influence soil organic carbon (SOC) sequestration. However, in Mollisols, the dynamics of the SOC fractions in response to amendment with wheat residue produced under eCO 2 and the corresponding microbial community composition remain unknown. Such investigation is essential to residue management, which affects the soil quality and productivity of future farming systems. To narrow this knowledge gap, 13 C-labeled shoot and root residue derived from ambient CO 2 (aCO 2 ) or eCO 2 were amended into Mollisols and incubated for 200days. The soil was sampled during the incubation period to determine the residue-C retained in the three SOC fractions, i.e., coarse intra-aggregate particulate organic C (coarse iPOC), fine iPOC and mineral-associated organic C (MOC). The soil bacterial community was assessed using a MiSeq sequencing instrument. The results showed that the increase in SOC concentrations attributable to the application of the wheat residue primarily occurred in the coarse iPOC fraction. Compared with the aCO 2 -derived shoot residue, the amendment of eCO 2 -derived shoot residue resulted in greater SOC concentrations, whereas no significant differences (P>0.05) were observed between the aCO 2 - and eCO 2 -derived roots. Principal coordinates analysis (PCoA) showed that the residue amendment significantly (P≤0.05) altered the bacterial community composition compared with the non-residue amendment. Additionally, the bacterial community in the aCO 2 -derived shoot treatment differed from those in the other residue treatments until day 200 of the incubation period. The eCO 2 -derived shoot treatment significantly increased (P≤0.05) the relative abundances of the genera Acidobacteriaceae_(Subgroup_1)_uncultured, Bryobacter, Candidatus_Solibacter, Gemmatimonas and Nitrosomonadaceae_uncultured, whereas the opposite trend was observed in Nonomuraea, Actinomadura, Streptomyces and Arthrobacter (P≤0.05). These results imply that the response of the microbial community to the eCO 2 -derived shoot treatment is associated with its contribution to the POC fractions. Copyright © 2017 Elsevier B.V. All rights reserved.

Biochar-stimulated plant performance is strongly linked to microbial diversity and metabolic potential in the rhizosphere.

PubMed

Kolton, Max; Graber, Ellen R; Tsehansky, Ludmila; Elad, Yigal; Cytryn, Eddie

2017-02-01

The 'biochar effect' depicts a phenomenon in which biochar soil amendment enhances plant performance by promoting growth and suppressing disease. Although this phenomenon has been observed in numerous studies, the mode of action that explains it is currently unknown. In order to elucidate mechanisms responsible for the 'biochar effect', we comprehensively monitored tomato plant development and resistance to the foliar fungal pathogen Botrytis cinerea, in biochar-amended and nonamended soils using native biochar and washed biochar, striped of labile chemical constituents. We concomitantly assessed bacterial community succession in the rhizosphere by high-throughput 16S rRNA gene amplicon sequencing and carbon-source utilization profiling. Biochar had little impact on plant physiological parameters. However, both native and washed biochar treatments were characterized by higher rhizosphere bacterial diversity and enhanced carbohydrate and phenolic compound utilization rates coupled to stimulation of bacteria known to degrade phenolic compounds. This study indicates that the 'biochar effect' is at least partially dictated by increased diversity and changes in metabolic potential in the rhizosphere microbiome, which is primarily triggered by the recalcitrant carbon backbone of the biochar and tightly bound compounds. It corresponds to the growing consensus that soil amendments which enhance microbial diversity have important benefits to ecosystem functioning. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Studying the First Amendment.

ERIC Educational Resources Information Center

Scales, Pat

2000-01-01

Discussion of censorship against books in public and school libraries focuses on intellectual freedom; First Amendment rights; and curriculum development to include lessons on the First Amendment. Offers suggestions for activities focusing on censorship and banned books. (LRW)

Soil microbial properties after long-term swine slurry application to conventional and no-tillage systems in Brazil.

PubMed

Balota, Elcio L; Machineski, Oswaldo; Hamid, Karima I A; Yada, Ines F U; Barbosa, Graziela M C; Nakatani, Andre S; Coyne, Mark S

2014-08-15

Swine waste can be used as an agricultural fertilizer, but large amounts may accumulate excess nutrients in soil or contaminate the surrounding environment. This study evaluated long-term soil amendment (15 years) with different levels of swine slurry to conventional (plow) tillage (CT) and no tillage (NT) soils. Long-term swine slurry application did not affect soil organic carbon. Some chemical properties, such as calcium, base saturation, and aluminum saturation were significantly different within and between tillages for various application rates. Available P and microbial parameters were significantly affected by slurry addition. Depending on tillage, soil microbial biomass and enzyme activity increased up to 120 m(3) ha(-1) year(-1) in all application rates. The NT system had higher microbial biomass and activity than CT at all application levels. There was an inverse relationship between the metabolic quotient (qCO2) and MBC, and the qCO2 was 53% lower in NT than CT. Swine slurry increased overall acid phosphatase activity, but the phosphatase produced per unit of microbial biomass decreased. A comparison of data obtained in the 3rd and 15th years of swine slurry application indicated that despite slurry application the CT system degraded with time while the NT system had improved values of soil quality indicators. For these Brazilian oxisols, swine slurry amendment was insufficient to maintain soil quality parameters in annual crop production without additional changes in tillage management. Copyright © 2014 Elsevier B.V. All rights reserved.

Tracking heterotrophic and autotrophic carbon cycling by magnetotactic bacteria in freshwater sediments using DNA stable isotope probing

NASA Astrophysics Data System (ADS)

Kürşat Coşkun, Ömer; Roud, Sophie; He, Kuang; Petersen, Nikolai; Gilder, Stuart; Orsi, William D.

2017-04-01

Magnetotactic bacteria (MTB) are diverse, widespread, motile prokaryotes which biomineralize nanosize magnetic minerals, either magnetite or gregite, under highly conserved genetic control and have magnetotaxis to align their position in aquatic environment according to Earth's magnetic field. They play important roles on some geobiological cycle of important minerals such as iron, sulphur, nitrogen and carbon. Yet, to date, their importance in carbon cycle and carbon source in their natural environment have not been previously studied. In this study, we focused on freshwater benthic carbon cycling of MTB and total bacteria using DNA stable isotope probing (DNA-SIP) technique coupled with quantitative PCR (qPCR). Pond sediments from Unterlippach (Germany) were amended with 13C-labelled sodium bicarbonate and 13C-labelled organic matter, and incubated in the dark over a two week time period. Applying separate qPCR assays specific for total bacteria and MTB, respectively, allowed us to estimate the contribution of MTB to total heterotrophic and autotrophic carbon cycling via DNA-SIP. After one week, there was a slight degree of autotrophic activity which increased markedly after two weeks. Comparing total DNA to the qPCR data revealed that changes in the buoyant density of DNA was due mainly to autotrophic bacterial production. DNA-SIP also identified heterotrophic utilization of 13C-labelled organic matter by MTB after 1 week. The qPCR data also allowed us to estimate uptake rates based on the incubation times for heterotrophic and autotrophic MTB. High-throughput DNA sequencing of 16S rRNA genes showed that most of the MTB involved in carbon cycling were related to the Magnetococcus genus. This study sheds light on the carbon sources for MTB in a natural environment and helps unravel their ecological role in the carbon cycle.

Shifts in soil chemical properties and bacterial communities responding to biotransformed dry olive residue used as organic amendment.

PubMed

Siles, José A; Cajthaml, Tomas; Hernández, Paola; Pérez-Mendoza, Daniel; García-Romera, Inmaculada; Sampedro, Inmaculada

2015-07-01

Dry olive residue (DOR) is a waste product derived from olive oil extraction and has been proposed as an organic amendment. However, it has been demonstrated that a pre-treatment, such as its transformation by saprophytic fungi, is required before DOR soil application. A greenhouse experiment was designed where 0 and 50 g kg(-1) of raw DOR (DOR), Coriolopsis floccosa-transformed DOR (CORDOR) and Fusarium oxysporum-transformed DOR (FUSDOR) were added to soil. Analyses of the soil chemical properties as well as the structure and relative abundance of bacterial and actinobacterial communities were conducted after 0, 30 and 60 days following amendment. The different amendments produced a slight decrease in soil pH and significant increases in carbon fractions, C/N ratios, phenols and K, with these increases being more significant after DOR application. Quantitative PCR assays of the 16S rRNA gene and PLFA analyses showed that all amendments favoured bacterial growth at 30 and 60 days, although actinobacterial proliferation was more evident after CORDOR and FUSDOR application at 60 days. Bacterial and actinobacterial DGGE multivariate analyses showed that the amendments produced structural changes in both communities, especially after 60 days of amendment. PLFA data analysis identified changes in soil microbial communities according to the amendment considered, with FUSDOR and CORDOR being less disruptive than DOR. Finally, integrated analysis of all data monitored in the present study enabled us to conclude that the greatest impact on soil properties was caused by DOR at 30 days and that soil showed some degree of resilience after this time.

Effects of topsoil treatments on afforestation in a dry Mediterranean climate (southern Spain)

NASA Astrophysics Data System (ADS)

Hueso-González, Paloma; Francisco Martínez-Murillo, Juan; Damian Ruiz-Sinoga, Jose

2016-10-01

Afforestation programs in semiarid areas are associated with a high level of sapling mortality. Therefore, the development of alternative low-cost and low-environmental-impact afforestation methods that ensure the survival of seedlings is crucial for improving the efficiency of Mediterranean forest management. This study assessed the effects of five types of soil amendments on the afforestation success (e.g., plant growth and survival) of a Mediterranean semiarid area. The amendments tested were (i) straw mulch; (ii) mulch containing chipped branches of Aleppo pine (Pinus halepensis L.); (iii) sheep manure compost; (iv) sewage sludge from a wastewater treatment plant; and (v) TerraCottem hydroabsorbent polymer. We hypothesized that in the context of dry Mediterranean climatic conditions, the use of organic amendments would enhance plant establishment and ensure successful afforestation. The results showed that afforestation success varied among the various soil amendment treatments in the experimental plots. The amendments had no effect on soil organic carbon, pH, or salinity, but the results indicated that the addition of mulch or hydroabsorbent polymer can reduce transplant stress by increasing the soil water available for plant growth throughout the hydrological year, and potentially improve the success of afforestation by reducing plant mortality.

Influence of biochar on the enantioselective behavior of the chiral fungicide metalaxyl in soil

NASA Astrophysics Data System (ADS)

Gámiz, Beatriz; Pignatello, Joseph J.; Hermosín, María Carmen; Cox, Lucía; Celis, Rafael

2015-04-01

Chiral pesticides comprise an emerging and important class of organic pollutants currently, accounting for more than a quarter of used pesticides. Consequently, the contamination problems caused by chiral pesticides are concern matter and factors affecting enantioselective processes of chiral pesticides in soil need to be understood. For example, certain soil management practices, such as the use of organic amendments, can affect the enantioselective behavior of chiral pesticides in soils. Recently, biochar (BC), i.e. organic matter subjected to pyrolysis, has been proposed as organic amendment due to beneficial properties such as its high stability against decay in soil environments and its apparent ability to influence the availability of nutrients. BC is considered to be more biologically inert as compared to otherforms of organic carbon. However, its side-effects on the enantioselectivity of processes affecting the fate of chiral pesticides is unknown. The aim of this study was to assess the effect of biochar (BC) on the enantioselectivity of sorption, degradation, and leaching of the chiral fungicide metalaxyl in an agricultural soil. Amending the soil with BC (2% w/w) resulted in 3 times higher sorption of metalaxyl enantiomers compared to unamended soil, but no enantioselectivity in the process was observed. Moreover, both enantiomers showed some resistance to be desorbed in BC-amended soil compared to unamended soil. Dissipation studies revealed that the degradation of metalaxylwas more enantioselective in the unamended soil than in BC-amended soil. In unamended soil, R-metalaxyl(biologically active) and S- metalaxyl had half-lives (t1/2) of 3 and 34 days, respectively. BC enhanced the persistence of both enantiomers in the soil, with R-metalaxyl being degraded faster (t1/2=43 days) than S-metalaxyl (t1/2= 100 days). The leaching of both S-and R-metalaxyl was almost suppressed after amending the soil with BC; less than 10% of the fungicide applied to soil columns was recovered in leachates, in contrast to significantly higher percentages leachedin unamended soil, being the process more enantioselective in the latter case. Finally, total recoveries of both enantiomers were greater for BC-amended soil columns than for unamended soil columns, indicating reduced degradation in BC- amended soil. Our findings illustrated the ability of biochar to modify the enantioselectivity behavior of metalaxyl in soil by its high sorption capacity. BC could contribute to reduce the current agronomic doses used for chiral pesticides to deplete the contamination problems associated with their use, and also to act as an immobilizing amendment in soil remediation strategies. Acknowledgments: MINECO (AGL2011-23779), FACCE-JPI (Designchar4food), JA (AGR-264) and FEDER-FSE (OP 2007-2013).

76 FR 6762 - Drill Pipe From the People's Republic of China: Amended Final Determination of Critical...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-08

... the specific chemistry of the steel (i.e., carbon, stainless steel, or other alloy steel), and without... collar green tubes) and unfinished drill pipe (including drill pipe green tubes, which are tubes meeting...

Carbon Dioxide as a Fire Suppressant: Examining the Risks

EPA Pesticide Factsheets

Under the Clean Air Act Amendments of 1990, the U.S. Environmental Protection Agency (EPA) has the statutory authority to set phase-out dates for ozone-depleting substances (ODS) and to evaluate potential risks posed by proposed ODS substitutes.

Cover crop and CO2 emissions

USDA-ARS?s Scientific Manuscript database

Agricultural land management practices account for about 50% of soil organic carbon (SOC) loss. Restoring SOC is important to soil productivity and fertility. Management strategies to rebuild SOC include addition of manure or other organic amendments, increasing root biomass from crops, leaving crop...

SEQUESTERING AGENTS FOR METAL IMMOBILIZATION APPLICATION TO THE DEVELOPMENT OF ACTIVE CAPS IN FRESH AND SALT WATER SEDIMENTS

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

Knox, A; Michael Paller, M

2006-11-17

This research evaluated the removal of inorganic contaminants by a variety of amendments and mixtures of amendments in fresh and salt water. A series of removal and retention batch experiments was conducted to identify the best treatment for metal removal. Metal removal by the amendments was evaluated by calculating the partition coefficient and percent removal. Retention of metals by the amendments was evaluated in retention (desorption) studies in which residue from the removal studies was extracted with 1 M MgCl{sub 2} solution. The results indicated that phosphate amendments, some organoclays (e.g., OCB-750), and the biopolymer, chitosan, are very effective inmore » removal and retention of metals in both fresh and salt water. These amendments are being evaluated further as components in the development of active caps for sediment remediation.« less

Soil bacterial communities of a calcium-supplemented and a reference watershed at the Hubbard Brook Experimental Forest (HBEF), New Hampshire, USA.

PubMed

Sridevi, Ganapathi; Minocha, Rakesh; Turlapati, Swathi A; Goldfarb, Katherine C; Brodie, Eoin L; Tisa, Louis S; Minocha, Subhash C

2012-03-01

Soil Ca depletion because of acidic deposition-related soil chemistry changes has led to the decline of forest productivity and carbon sequestration in the northeastern USA. In 1999, acidic watershed (WS) 1 at the Hubbard Brook Experimental Forest (HBEF), NH, USA was amended with Ca silicate to restore soil Ca pools. In 2006, soil samples were collected from the Ca-amended (WS1) and reference watershed (WS3) for comparison of bacterial community composition between the two watersheds. The sites were about 125 m apart and were known to have similar stream chemistry and tree populations before Ca amendment. Ca-amended soil had higher Ca and P, and lower Al and acidity as compared with the reference soils. Analysis of bacterial populations by PhyloChip revealed that the bacterial community structure in the Ca-amended and the reference soils was significantly different and that the differences were more pronounced in the mineral soils. Overall, the relative abundance of 300 taxa was significantly affected. Numbers of detectable taxa in families such as Acidobacteriaceae, Comamonadaceae, and Pseudomonadaceae were lower in the Ca-amended soils, while Flavobacteriaceae and Geobacteraceae were higher. The other functionally important groups, e.g. ammonia-oxidizing Nitrosomonadaceae, had lower numbers of taxa in the Ca-amended organic soil but higher in the mineral soil. Published 2011. This article is a U.S. Government work and is in the public domain in the USA.

15 CFR 922.72 - Prohibited or otherwise regulated activities-Sanctuary-wide.

Code of Federal Regulations, 2012 CFR

2012-01-01

... authorized by the Marine Mammal Protection Act, as amended, (MMPA), 16 U.S.C. 1361 et seq., Endangered Species Act, as amended, (ESA), 16 U.S.C. 1531 et seq., Migratory Bird Treaty Act, as amended, (MBTA), 16... classification) approved in accordance with section 312 of the Federal Water Pollution Control Act, as amended...

Metal leaching in mine tailings: short-term impact of biochar and wood ash amendments.

PubMed

Beauchemin, Suzanne; Clemente, Joyce S; MacKinnon, Ted; Tisch, Bryan; Lastra, Rolando; Smith, Derek; Kwong, John

2015-01-01

Biochar is perceived as a promising amendment to reclaim degraded, metal-contaminated lands. The objective of this study was to compare the potential of biochar and wood ash amendments to reduce metal(loid) leaching in mine tailings. A 2-mo leaching experiment was conducted in duplicate on acidic and alkaline tailings, each mixed with 5 wt.% of one of the following amendments: three wood-derived, fast-pyrolysis biochars (OC > 57 wt.%) and two wood ash materials (organic carbon [OC] ≤ 16 wt.%); a control test with no carbon input was also added. The columns were leached with water after 1, 2, 4, 8, 16, 32, and 64 d, and the leachates were monitored for dissolved metals, OC, and pH. For the acidic and alkaline tailings, the most significant impact on metal mobility was observed with wood ash materials due to their greater neutralization potential (>15% CaCO eq.) compared with biochar (≤3.3% CaCO eq.). An increase of 1 pH unit in the wood ash-treated alkaline tailings led to an undesirable mobilization of As and Se. The addition of biochar did not significantly reduce the leaching of the main contaminants (Cu and Ni in the acidic tailings and As in the alkaline tailings) over 2 mo. The Se attenuation noted in some biochar-treated acid tailings may be mainly due to a slight alkaline effect rather than Se removal by biochar, given the low capacity for the fresh biochars to retain Se under acidic conditions (pH 4.5). The increased loss of dissolved OC in the biochar-amended systems was of short duration and was not associated with metal(loid) mobilization. Copyright © Her Majesty the Queen in Right of Canada, as represented by the Minister of Agriculture and Agri-Food Canada.

Major Effect of Hydrogen Peroxide on Bacterioplankton Metabolism in the Northeast Atlantic

PubMed Central

Baltar, Federico; Reinthaler, Thomas; Herndl, Gerhard J.; Pinhassi, Jarone

2013-01-01

Reactive oxygen species such as hydrogen peroxide have the potential to alter metabolic rates of marine prokaryotes, ultimately impacting the cycling and bioavailability of nutrients and carbon. We studied the influence of H2O2 on prokaryotic heterotrophic production (PHP) and extracellular enzymatic activities (i.e., β-glucosidase [BGase], leucine aminopeptidase [LAPase] and alkaline phosphatase [APase]) in the subtropical Atlantic. With increasing concentrations of H2O2 in the range of 100–1000 nM, LAPase, APase and BGase were reduced by up to 11, 23 and 62%, respectively, in the different water layers. Incubation experiments with subsurface waters revealed a strong inhibition of all measured enzymatic activities upon H2O2 amendments in the range of 10–500 nM after 24 h. H2O2 additions also reduced prokaryotic heterotrophic production by 36–100% compared to the rapid increases in production rates occurring in the unamended controls. Our results indicate that oxidative stress caused by H2O2 affects prokaryotic growth and hydrolysis of specific components of the organic matter pool. Thus, we suggest that oxidative stress may have important consequences on marine carbon and energy fluxes. PMID:23593386

In situ treatment with activated carbon reduces bioaccumulation in aquatic food chains.

PubMed

Kupryianchyk, D; Rakowska, M I; Roessink, I; Reichman, E P; Grotenhuis, J T C; Koelmans, A A

2013-05-07

In situ activated carbon (AC) amendment is a new direction in contaminated sediment management, yet its effectiveness and safety have never been tested on the level of entire food chains including fish. Here we tested the effects of three different AC treatments on hydrophobic organic chemical (HOC) concentrations in pore water, benthic invertebrates, zooplankton, and fish (Leuciscus idus melanotus). AC treatments were mixing with powdered AC (PAC), mixing with granular AC (GAC), and addition-removal of GAC (sediment stripping). The AC treatments resulted in a significant decrease in HOC concentrations in pore water, benthic invertebrates, zooplankton, macrophytes, and fish. In 6 months, PAC treatment caused a reduction of accumulation of polychlorobiphenyls (PCB) in fish by a factor of 20, bringing pollutant levels below toxic thresholds. All AC treatments supported growth of fish, but growth was inhibited in the PAC treatment, which was likely explained by reduced nutrient concentrations, resulting in lower zooplankton (i.e., food) densities for the fish. PAC treatment may be advised for sites where immediate ecosystem protection is required. GAC treatment may be equally effective in the longer term and may be adequate for vulnerable ecosystems where longer-term protection suffices.

Organic Amendments to Avocado Crops Induce Suppressiveness and Influence the Composition and Activity of Soil Microbial Communities

PubMed Central

Bonilla, Nuria; Vida, Carmen; Martínez-Alonso, Maira; Landa, Blanca B.; Gaju, Nuria; Cazorla, Francisco M.

2015-01-01

One of the main avocado diseases in southern Spain is white root rot caused by the fungus Rosellinia necatrix Prill. The use of organic soil amendments to enhance the suppressiveness of natural soil is an inviting approach that has successfully controlled other soilborne pathogens. This study tested the suppressive capacity of different organic amendments against R. necatrix and analyzed their effects on soil microbial communities and enzymatic activities. Two-year-old avocado trees were grown in soil treated with composted organic amendments and then used for inoculation assays. All of the organic treatments reduced disease development in comparison to unamended control soil, especially yard waste (YW) and almond shells (AS). The YW had a strong effect on microbial communities in bulk soil and produced larger population levels and diversity, higher hydrolytic activity and strong changes in the bacterial community composition of bulk soil, suggesting a mechanism of general suppression. Amendment with AS induced more subtle changes in bacterial community composition and specific enzymatic activities, with the strongest effects observed in the rhizosphere. Even if the effect was not strong, the changes caused by AS in bulk soil microbiota were related to the direct inhibition of R. necatrix by this amendment, most likely being connected to specific populations able to recolonize conducive soil after pasteurization. All of the organic amendments assayed in this study were able to suppress white root rot, although their suppressiveness appears to be mediated differentially. PMID:25769825

Soil ionomic and enzymatic responses and correlations to fertilizations amended with and without organic fertilizer in long-term experiments.

PubMed

Feng, Xumeng; Ling, Ning; Chen, Huan; Zhu, Chen; Duan, Yinghua; Peng, Chang; Yu, Guanghui; Ran, Wei; Shen, Qirong; Guo, Shiwei

2016-04-15

To investigate potential interactions between the soil ionome and enzyme activities affected by fertilization with or without organic fertilizer, soil samples were collected from four long-term experiments over China. Irrespective of variable interactions, fertilization type was the major factor impacting soil ionomic behavior and accounted for 15.14% of the overall impact. Sampling site was the major factor affecting soil enzymatic profile and accounted for 34.25% of the overall impact. The availabilities of Pb, La, Ni, Co, Fe and Al were significantly higher in soil with only chemical fertilizer than the soil with organic amendment. Most of the soil enzyme activities, including α-glucosidase activity, were significantly activated by organic amendment. Network analysis between the soil ionome and the soil enzyme activities was more complex in the organic-amended soils than in the chemical fertilized soils, whereas the network analysis among the soil ions was less complex with organic amendment. Moreover, α-glucosidase was revealed to generally harbor more corrections with the soil ionic availabilities in network. We concluded that some of the soil enzymes activated by organic input can make the soil more vigorous and stable and that the α-glucosidase revealed by this analysis might help stabilize the soil ion availability.

Soil ionomic and enzymatic responses and correlations to fertilizations amended with and without organic fertilizer in long-term experiments

PubMed Central

Feng, Xumeng; Ling, Ning; Chen, Huan; Zhu, Chen; Duan, Yinghua; Peng, Chang; Yu, Guanghui; Ran, Wei; Shen, Qirong; Guo, Shiwei

2016-01-01

To investigate potential interactions between the soil ionome and enzyme activities affected by fertilization with or without organic fertilizer, soil samples were collected from four long-term experiments over China. Irrespective of variable interactions, fertilization type was the major factor impacting soil ionomic behavior and accounted for 15.14% of the overall impact. Sampling site was the major factor affecting soil enzymatic profile and accounted for 34.25% of the overall impact. The availabilities of Pb, La, Ni, Co, Fe and Al were significantly higher in soil with only chemical fertilizer than the soil with organic amendment. Most of the soil enzyme activities, including α-glucosidase activity, were significantly activated by organic amendment. Network analysis between the soil ionome and the soil enzyme activities was more complex in the organic-amended soils than in the chemical fertilized soils, whereas the network analysis among the soil ions was less complex with organic amendment. Moreover, α-glucosidase was revealed to generally harbor more corrections with the soil ionic availabilities in network. We concluded that some of the soil enzymes activated by organic input can make the soil more vigorous and stable and that the α-glucosidase revealed by this analysis might help stabilize the soil ion availability. PMID:27079657

Effects of inorganic and organic amendment on soil chemical properties, enzyme activities, microbial community and soil quality in yellow clayey soil.

PubMed

Liu, Zhanjun; Rong, Qinlei; Zhou, Wei; Liang, Guoqing

2017-01-01

Understanding the effects of external organic and inorganic components on soil fertility and quality is essential for improving low-yielding soils. We conducted a field study over two consecutive rice growing seasons to investigate the effect of applying chemical fertilizer (NPK), NPK plus green manure (NPKG), NPK plus pig manure (NPKM), and NPK plus straw (NPKS) on the soil nutrient status, enzyme activities involved in C, N, P, and S cycling, microbial community and rice yields of yellow clayey soil. Results showed that the fertilized treatments significantly improved rice yields over the first three experimental seasons. Compared with the NPK treatment, organic amendments produced more favorable effects on soil productivity. Notably, the NPKM treatment exhibited the highest levels of nutrient availability, microbial biomass carbon (MBC), activities of most enzymes and the microbial community. This resulted in the highest soil quality index (SQI) and rice yield, indicating better soil fertility and quality. Significant differences in enzyme activities and the microbial community were observed among the treatments, and redundancy analysis showed that MBC and available N were the key determinants affecting the soil enzyme activities and microbial community. The SQI score of the non-fertilized control (0.72) was comparable to that of the NPK (0.77), NPKG (0.81) and NPKS (0.79) treatments but significantly lower compared with NPKM (0.85). The significant correlation between rice yield and SQI suggests that SQI can be a useful to quantify soil quality changes caused by different agricultural management practices. The results indicate that application of NPK plus pig manure is the preferred option to enhance SOC accumulation, improve soil fertility and quality, and increase rice yield in yellow clayey soil.

Effects of inorganic and organic amendment on soil chemical properties, enzyme activities, microbial community and soil quality in yellow clayey soil

PubMed Central

Liu, Zhanjun; Rong, Qinlei; Zhou, Wei; Liang, Guoqing

2017-01-01

Understanding the effects of external organic and inorganic components on soil fertility and quality is essential for improving low-yielding soils. We conducted a field study over two consecutive rice growing seasons to investigate the effect of applying chemical fertilizer (NPK), NPK plus green manure (NPKG), NPK plus pig manure (NPKM), and NPK plus straw (NPKS) on the soil nutrient status, enzyme activities involved in C, N, P, and S cycling, microbial community and rice yields of yellow clayey soil. Results showed that the fertilized treatments significantly improved rice yields over the first three experimental seasons. Compared with the NPK treatment, organic amendments produced more favorable effects on soil productivity. Notably, the NPKM treatment exhibited the highest levels of nutrient availability, microbial biomass carbon (MBC), activities of most enzymes and the microbial community. This resulted in the highest soil quality index (SQI) and rice yield, indicating better soil fertility and quality. Significant differences in enzyme activities and the microbial community were observed among the treatments, and redundancy analysis showed that MBC and available N were the key determinants affecting the soil enzyme activities and microbial community. The SQI score of the non-fertilized control (0.72) was comparable to that of the NPK (0.77), NPKG (0.81) and NPKS (0.79) treatments but significantly lower compared with NPKM (0.85). The significant correlation between rice yield and SQI suggests that SQI can be a useful to quantify soil quality changes caused by different agricultural management practices. The results indicate that application of NPK plus pig manure is the preferred option to enhance SOC accumulation, improve soil fertility and quality, and increase rice yield in yellow clayey soil. PMID:28263999

Sorption/Desorption and Transport of Trichloroethene in Freshly-amended, Synthetically- aged, and Field-contaminated Aquifer Material

NASA Astrophysics Data System (ADS)

Johnson, G. R.; Norris, D. K.; Brusseau, M. L.

2008-12-01

This study investigates the effect of long-term contaminant aging on the sorption/desorption and transport of trichloroethene in a low organic-carbon content aquifer material collected from the source zone of a chlorinated-solvent contaminated federal Superfund site in Arizona. This was accomplished by comparing elution behavior for field-contaminated, synthetically-aged (contact times of approximately four years), and freshly-amended aquifer material. Elution of trichloroethene exhibited extensive low-concentration tailing, despite minimal retention of trichloroethene by the aquifer material. The observed nonideal behavior indicates significant mass-transfer constraints influenced trichloroethene transport in this aquifer material. The elution behavior of trichloroethene for the field-contaminated and aged treatments was essentially identical to that observed for the fresh treatments. In addition, the results of three independent mass- balance analyses, total mass eluted, solvent-extraction analysis of residual sorbed mass, and flow- interruption rebound, showed equivalent recoveries for the aged and fresh treatments. These results indicate that long-term contaminant aging did not significantly influence the transport and fate behavior of trichloroethene in this low organic-carbon aquifer material. The observed nonideal behavior of trichloroethene (i.e., nonlinear sorption and significantly rate-limited sorption/desorption) suggests physically condensed carbonaceous material, comprising 61% of this media's organic-carbon content, mediates the transport and fate behavior of trichloroethene in this low organic-carbon content aquifer material.

Reclamation of a burned forest soil with municipal waste compost: macronutrient dynamic and improved vegetation cover recovery.

PubMed

Guerrero, C; Gómez, I; Moral, R; Mataix-Solera, J; Mataix-Beneyto, J; Hernández, T

2001-02-01

The reclamation of burned soils in Mediterranean environments is of paramount importance in order to increase the levels of soil protection and minimise erosion and soil loss. The changes produced in the content of total organic carbon (TOC), N (Kjeldahl) and available P, K, Ca and Mg by the addition of different doses of a municipal solid waste compost to a burned soil were evaluated during one year. The effect of organic amendment on the improvement in the vegetation cover after one year was also evaluated. The organic amendment, particularly at a high dose, increased the TOC and N-Kjeldahl content of the soil in a closely related way. The levels of available K in soil were also enhanced by the organic amendment. Although the effects on all three parameters tended to decrease with time, their values in the amended soils were higher than in the control soil, which clearly indicates the improvement in the chemical quality of the soil brought about by the organic amendment. The available P content did not seem to be influenced by organic treatment, while available Mg levels were higher than in the control during the first 4 months following organic amendment. The application of compost to the burned soil improved its fertility and favoured rapid vegetal recovery, thus minimising the risk of soil erosion.

40 CFR 90.5 - Acronyms and abbreviations.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Materials CAA—Clean Air Act CAAA—Clean Air Act Amendments of 1990 CLD—chemiluminescent detector CO—Carbon... per kilowatt hour HC—hydrocarbons HCLD—heated chemiluminescent detector HFID—heated flame ionization detector ICI—independent Commercial Importer NDIR—non-dispersive infrared analyzer NIST—National Institute...

40 CFR 90.5 - Acronyms and abbreviations.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Materials CAA—Clean Air Act CAAA—Clean Air Act Amendments of 1990 CLD—chemiluminescent detector CO—Carbon... per kilowatt hour HC—hydrocarbons HCLD—heated chemiluminescent detector HFID—heated flame ionization detector ICI—independent Commercial Importer NDIR—non-dispersive infrared analyzer NIST—National Institute...

40 CFR 90.5 - Acronyms and abbreviations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Materials CAA—Clean Air Act CAAA—Clean Air Act Amendments of 1990 CLD—chemiluminescent detector CO—Carbon... per kilowatt hour HC—hydrocarbons HCLD—heated chemiluminescent detector HFID—heated flame ionization detector ICI—independent Commercial Importer NDIR—non-dispersive infrared analyzer NIST—National Institute...

40 CFR 90.5 - Acronyms and abbreviations.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Materials CAA—Clean Air Act CAAA—Clean Air Act Amendments of 1990 CLD—chemiluminescent detector CO—Carbon... per kilowatt hour HC—hydrocarbons HCLD—heated chemiluminescent detector HFID—heated flame ionization detector ICI—independent Commercial Importer NDIR—non-dispersive infrared analyzer NIST—National Institute...

40 CFR 90.5 - Acronyms and abbreviations.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Materials CAA—Clean Air Act CAAA—Clean Air Act Amendments of 1990 CLD—chemiluminescent detector CO—Carbon... per kilowatt hour HC—hydrocarbons HCLD—heated chemiluminescent detector HFID—heated flame ionization detector ICI—independent Commercial Importer NDIR—non-dispersive infrared analyzer NIST—National Institute...

75 FR 20813 - Certain Magnesia Carbon Bricks from the People's Republic of China: Amended Preliminary...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-21

... other errors, would result in (1) a change of at least five absolute percentage points in, but not less...) preliminary determination, or (2) a difference between a weighted-average dumping margin of zero or de minimis...

15 CFR 922.72 - Prohibited or otherwise regulated activities-Sanctuary-wide.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Mammal Protection Act, as amended, (MMPA), 16 U.S.C. 1361 et seq., Endangered Species Act, as amended, (ESA), 16 U.S.C. 1531 et seq., Migratory Bird Treaty Act, as amended, (MBTA), 16 U.S.C. 703 et seq., or... classification) approved in accordance with section 312 of the Federal Water Pollution Control Act, as amended...

15 CFR 922.152 - Prohibited or otherwise regulated activities.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Protection Act, as amended, (MMPA), 16 U.S.C. 1361 et seq., the Endangered Species Act, as amended, (ESA), 16 U.S.C. 1531 et seq., and the Migratory Bird Treaty Act, as amended, (MBTA), 16 U.S.C. 703 et seq... section 312 of the Federal Water Pollution Control Act, as amended, (FWPCA), 33 U.S.C. 1322 et seq.; (C...

15 CFR 922.72 - Prohibited or otherwise regulated activities-Sanctuary-wide.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Mammal Protection Act, as amended, (MMPA), 16 U.S.C. 1361 et seq., Endangered Species Act, as amended, (ESA), 16 U.S.C. 1531 et seq., Migratory Bird Treaty Act, as amended, (MBTA), 16 U.S.C. 703 et seq., or... classification) approved in accordance with section 312 of the Federal Water Pollution Control Act, as amended...

15 CFR 922.152 - Prohibited or otherwise regulated activities.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Protection Act, as amended, (MMPA), 16 U.S.C. 1361 et seq., the Endangered Species Act, as amended, (ESA), 16 U.S.C. 1531 et seq., and the Migratory Bird Treaty Act, as amended, (MBTA), 16 U.S.C. 703 et seq... section 312 of the Federal Water Pollution Control Act, as amended, (FWPCA), 33 U.S.C. 1322 et seq.; (C...

15 CFR 922.152 - Prohibited or otherwise regulated activities.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Protection Act, as amended, (MMPA), 16 U.S.C. 1361 et seq., the Endangered Species Act, as amended, (ESA), 16 U.S.C. 1531 et seq., and the Migratory Bird Treaty Act, as amended, (MBTA), 16 U.S.C. 703 et seq... section 312 of the Federal Water Pollution Control Act, as amended, (FWPCA), 33 U.S.C. 1322 et seq.; (C...

30 CFR 925.12 - State program provisions and amendments disapproved.

Code of Federal Regulations, 2010 CFR

2010-07-01

... § 925.12 State program provisions and amendments disapproved. (a) The amendment at 10 CSR 40-4.030(4)(A... mining activities. (b) The amendment at 10 CSR 40-4.030(4)(B), submitted on December 14 and 18, 1987, is... land use. (c) The definitions of “coal processing plant” and “coal preparation plant” at 10 CSR 40-8...

Selective Enrichment of a Methanol-Utilizing Consortium Using Pulp and Paper Mill Waste Streams

NASA Astrophysics Data System (ADS)

Mockos, Gregory R.; Smith, William A.; Loge, Frank J.; Thompson, David N.

Efficient utilization of carbon inputs is critical to the economic viability of the current forest products sector. Input carbon losses occur in various locations within a pulp mill, including losses as volatile organics and wastewater. Opportunities exist to capture this carbon in the form of value-added products such as biodegradable polymers. Wasteactivated sludge from a pulp mill wastewater facility was enriched for 80 days for a methanol-utilizing consortium with the goal of using this consortium to produce biopolymers from methanol-rich pulp mill waste streams. Five enrichment conditions were utilized: three high-methanol streams from the kraft mill foul condensate system, one methanol-amended stream from the mill wastewater plant, and one methanol-only enrichment. Enrichment reactors were operated aerobically in sequencing batch mode at neutral pH and 25°C with a hydraulic residence time and a solids retention time of 4 days. Non-enriched waste activated sludge did not consume methanol or reduce chemical oxygen demand. With enrichment, however, the chemical oxygen demand reduction over 24-h feed/ decant cycles ranged from 79 to 89%, and methanol concentrations dropped below method detection limits. Neither the non-enriched waste-activated sludge nor any of the enrichment cultures accumulated polyhydroxyalkanoates (PHAs) under conditions of nitrogen sufficiency. Similarly, the non-enriched waste activated sludge did not accumulate PHAs under nitrogen-limited conditions. By contrast, enriched cultures accumulated PHAs to nearly 14% on a dry weight basis under nitrogen-limited conditions. This indicates that selectively enriched pulp mill waste activated sludge can serve as an inoculum for PHA production from methanol-rich pulp mill effluents.

Effects of poultry manure on soil biochemical properties in phthalic acid esters contaminated soil.

PubMed

Gao, Jun; Qin, Xiaojian; Ren, Xuqin; Zhou, Haifeng

2015-12-01

This study aimed to evaluate the effects of poultry manure (PM) on soil biological properties in DBP- and DEHP-contaminated soils. An indoor incubation experiment was conducted. Soil microbial biomass C (Cmic), soil enzymatic activities, and microbial phospholipid fatty acid (PLFA) concentrations were measured during incubation period. The results indicated that except alkaline phosphatase activity, DBP and DEHP had negative effects on Cmic, dehydrogenase, urease, protease activities, and contents of total PLFA. However, 5 % PM treatment alleviated the negative effects of PAEs on the above biochemical parameters. In DBP-contaminated soil, 5 % PM amendment even resulted in dehydroenase activity and Cmic content increasing by 17.8 and 11.8 % on the day 15 of incubation, respectively. During the incubation periods, the total PLFA contents decreased maximumly by 17.2 and 11.6 % in DBP- and DEHP-contaminated soils without PM amendments, respectively. Compared with those in uncontaminated soil, the total PLFA contents increased slightly and the value of bacPLFA/fugalPLFA increased significantly in PAE-contaminated soils with 5 % PM amendment. Nevertheless, in both contaminated soils, the effects of 5 % PM amendment on the biochemical parameters were not observed with 10 % PM amendment. In 10 % PM-amended soils, DBP and DEHP had little effect on Cmic, soil enzymatic activities, and microbial community composition. At the end of incubation, the effects of PAEs on these parameters disappeared, irrespective of PM amendment. The application of PM ameliorated the negative effect of PAEs on soil biological environment. However, further work is needed to study the effect of PM on soil microbial gene expression in order to explain the change mechanisms of soil biological properties.

Equilibrium and kinetic modeling of contaminant immobilization by activated carbon amended to sediments in the field.

PubMed

Rakowska, Magdalena I; Kupryianchyk, Darya; Koelmans, Albert A; Grotenhuis, Tim; Rijnaarts, Huub H M

2014-12-15

Addition of activated carbons (AC) to polluted sediments and soils is an attractive remediation technique aiming at reducing pore water concentrations of hydrophobic organic contaminants (HOCs). In this study, we present (pseudo-)equilibrium as well as kinetic parameters for sorption of a series of PAHs and PCBs to powdered and granular activated carbons (AC) after three different sediment treatments: sediment mixed with powdered AC (PAC), sediment mixed with granular AC (GAC), and addition of GAC followed by 2 d mixing and subsequent removal ('sediment stripping'). Remediation efficiency was assessed by quantifying fluxes of PAHs towards SPME passive samplers inserted in the sediment top layer, which showed that the efficiency decreased in the order of PAC > GAC stripping > GAC addition. Sorption was very strong to PAC, with Log KAC (L/kg) values up to 10.5. Log KAC values for GAC ranged from 6.3-7.1 and 4.8-6.2 for PAHs and PCBs, respectively. Log KAC values for GAC in the stripped sediment were 7.4-8.6 and 5.8-7.7 for PAH and PCB. Apparent first order adsorption rate constants for GAC (kGAC) in the stripping scenario were calculated with a first-order kinetic model and ranged from 1.6 × 10(-2) (PHE) to 1.7 × 10(-5) d(-1) (InP). Sorption affinity parameters did not change within 9 months post treatment, confirming the longer term effectiveness of AC in field applications for PAC and GAC. Copyright © 2014. Published by Elsevier Ltd.

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.

Assessment of the use potential of edible sea urchins (Paracentrotus lividus) processing waste within the agricultural system: influence on soil chemical and biological properties and bean (Phaseolus vulgaris) and wheat (Triticum vulgare) growth in an amended acidic soil.

PubMed

Garau, Giovanni; Castaldi, Paola; Deiana, Salvatore; Campus, Paolo; Mazza, Antonio; Deiana, Pietrino; Pais, Antonio

2012-10-30

In this study we evaluated the influence of ground purple sea urchin (Paracentrotus lividus) endoskeletons, a processing waste common to all edible sea urchin plants, on the chemical, biochemical and microbiological features of an acidic (pH 5.65) sandy-loam soil. The purple sea urchin endoskeletons were characterized by a high content of total carbonates (∼94%), a moderately alkaline pH in water (pH 7.88) and electrical conductivity values (3.55 mS/cm) very similar to those of commercial lime. To evaluate the influence of the P. lividus endoskeletons on soil properties four different amendment rates were tested, notably 0.5, 1.0, 3.0 and 5.0% based on soil dry weight, and the effects compared with those recorded on unamended control soil. The addition of the purple sea urchin processing waste caused an immediate and significant pH increase which was positively related to the rate of the amendment addition. After a six months equilibration period, the differences in soil pH were still evident and significant increases of electrical conductivity and available phosphorus were also detected in soils with the higher amendment rates. The number of heterotrophic and cellulolytic bacteria and actinomycetes significantly increased after amendment addition while the number of culturable fungi steadily declined. The analysis of the Biolog Community Level Physiological Profile indicated a clear influence of the purple sea urchin processing waste on the structure of the native microbial community while a significant increase of microbial functionality (i.e. dehydrogenase activity) was recorded in soil treated with the higher amendment rates (i.e. 3.0 and 5.0%). The improvement of microbial abundance and functionality as well as the change of the microbial community structure were ascribed to the pH shift induced by the P. lividus processing waste. To investigate possible effects on soil fertility, dwarf bean (Phaseolus vulgaris) and wheat (Triticum vulgare) growth were also assessed in a pot experiment. Plant growth was unaffected (wheat) or stimulated (bean) by the amendment addition in the 0.5-3.0% range while the higher amendment rate (i.e. 5.0%) was detrimental for both plant species indicating a phytotoxic effect which could be due to different factors such as an excess of calcium in soil, a suppression of Mg uptake or the higher EC values detected at the highest amendment rate. It is concluded that ground P. lividus endoskeletons have potential as a soil amendment to ameliorate chemical and biological properties of acidic Mediterranean soils. This seems particularly relevant, especially at the lower amendment rates, since for the first time, a sustainable management system is proposed for P. lividus processing waste, which foresees economic value in the sea urchin by-product through its re-use within the agricultural production system. Copyright © 2012 Elsevier Ltd. All rights reserved.

32 CFR 806b.2 - Basic guidelines.

Code of Federal Regulations, 2014 CFR

2014-07-01

... person exercises First Amendment rights. Exceptions are when: The Air Force has the permission of that..., an authorized law enforcement activity. First Amendment rights include, but are not limited to... decisions that deny individuals access to or amendment of their records through appellate procedures. ...

32 CFR 806b.2 - Basic guidelines.

Code of Federal Regulations, 2012 CFR

2012-07-01

... person exercises First Amendment rights. Exceptions are when: The Air Force has the permission of that..., an authorized law enforcement activity. First Amendment rights include, but are not limited to... decisions that deny individuals access to or amendment of their records through appellate procedures. ...

Hydraulic Test of a Bioretention Media Carbon Amendment

EPA Science Inventory

Rain gardens effectively remove some stressors from stormwater, but in most cases they show much smaller removal rates of nitrate, likely due to the high sand and low organic matter content of rain garden media inhibiting denitrification. A bench-scale experiment was conducted to...

77 FR 38801 - Environmental Impacts Statements; Notice of Availability

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-29

... Resource Management (VRM) Plan, Amendment, Class Designation, Carbon County, WY, Review Period Ends: 07/30... Final Vehicle Management Plan, Implementation, Denali National Park and Preserve, AK, Review Period Ends.... EIS No. 20120199, Final EIS, RUS, MS, ADOPTION--Kemper County Integrated Gasification Combined Cycle...

Investigating biochar as a tool for mine soil remediation

USDA-ARS?s Scientific Manuscript database

Biochar is a cost-effective, carbon negative soil amendment that can lead to improved soil quality. Research has also demonstrated the efficacy of biochar to sorb heavy metals and agricultural chemicals from contaminated soils, thus effectively reducing the potential for metal and chemical contamin...

Designing advanced biochar products for maximizing greenhouse gas mitigation potential

USDA-ARS?s Scientific Manuscript database

Greenhouse gas (GHG) emissions from agricultural operations continue to increase. Carbon enriched char materials like biochar have been described as a mitigation strategy. Utilization of biochar material as a soil amendment has been demonstrated to provide potentially further soil GHG suppression du...

Effect of pyrochar and hydrochar amendments on the mineralization of the herbicide isoproturon in an agricultural soil.

PubMed

Eibisch, Nina; Schroll, Reiner; Fuß, Roland

2015-09-01

Carbon (C)-rich, solid products from pyrolysis (pyrochars) and hydrothermal carbonization (HTC, hydrochars) are expected to reduce the bioavailability and bioaccessibility of pesticides as side effect of soil addition. To compare effects of different feedstocks (digestate, miscanthus, woodchips) and production processes (pyrolysis at 750°C, HTC at 200°C and 250°C), (14)C-labeled isoproturon (IPU) was applied at 0.75 kg ha(-)(1) to loamy sand amended either with 0.5% or 5% pyrochars or hydrochars, which was then incubated for 50d. Mineralization of IPU was measured as (14)C-CO2 released from soil-char composites. Pore-water and methanol extractable (14)C-IPU was quantified as well as non-extractable (14)C-residues (NER). Furthermore, C mineralization of pyrochars, hydrochars and feedstocks was studied to assess the relationship between IPU bioaccessibility and char decomposability. In pure soil, 8.1% of applied IPU was mineralized after 50d. This was reduced more strongly in pyrochar treatments (81 ± 6% reduction) than in hydrochar treatments (56 ± 25% reduction). Different feedstocks had no significantly different effect when 5% char was added, but their effect was significant and dependent on the production process in 0.5% amendments. Pesticide binding can occur by surface sorption as well as by diffusion and subsequent occlusion in micropores. The latter can be expected to result in high amounts of NER, as it was observed in the pyrochar treatments. Hydrochars were less stable than pyrochars and contained lower amounts of NER. Thus, in hydrochar amended soils, better accessibility of IPU to microbial degradation may be a result of full char decomposition within decades ensuring controlled pesticide degradation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Sunflower hulls degradation by co-composting with different nitrogen sources.

PubMed

Conghos, M M; Aguirre, M E; Santamaría, R M

2006-09-01

The decomposition of sunflower hull and its mixtures was examined under mesophilic (M) and thermophilic (T) temperatures during 100 days. Thermophilic conditions were used to define the composting process. Vetch, alfalfa and ammonium nitrate were used as nitrogen co-substrates, in 6 treatments: sunflower hulls alone (C), sunflower hulls plus ammonium nitrate (CN), sunflower hulls plus alfalfa (CA), sunflower hulls plus alfalfa and ammonium nitrate (CAV), sunflower hulls plus vetch (CV), sunflower hulls plus vetch and ammonium nitrate (CVN). Total organic carbon (TOC), oxidizable carbon (OC), dry matter, ashes content, total nitrogen (N), cellulose, hemicellulose, lignin, pH, electrical conductivity and C to N ratio were measured to asses the efficiency of the composting process and to determine the best amendment. Results show that sunflower hulls (Sh) treatment with the organic amendments had a better response than the inorganic ones. This was concluded from the variation in the fiberfractions, the decrease in dry matter and the major decrease in C to N ratio.

Assessing cellulolysis in passive treatment systems for mine drainage: a modified enzyme assay.

PubMed

McDonald, Corina M; Gould, W Douglas; Lindsay, Matthew B J; Blowes, David W; Ptacek, Carol J; Condon, Peter D

2013-01-01

A modified cellulase enzyme assay was developed to monitor organic matter degradation in passive treatment systems for mine drainage. This fluorogenic substrate method facilitates assessment of exo-(1,4)-β-D-glucanase, endo-(1,4)-β-D-glucanase, and β-glucosidase, which compose an important cellulase enzyme system. The modified method was developed and refined using samples of organic carbon-amended mine tailings from field experiments where sulfate reduction was induced as a strategy for managing water quality. Sample masses (3 g) and the number of replicates ( ≥ 3) were optimized. Matrix interferences within these metal-rich samples were found to be insignificant. Application of this modified cellulase assay method provided insight into the availability and degradation of organic carbon within the amended tailings. Results of this study indicate that cellulase enzyme assays can be applied to passive treatment systems for mine drainage, which commonly contain elevated concentrations of metals. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Defense Responses in Rice Induced by Silicon Amendment against Infestation by the Leaf Folder Cnaphalocrocis medinalis

PubMed Central

Han, Yongqiang; Li, Pei; Gong, Shaolong; Yang, Lang; Wen, Lizhang; Hou, Maolin

2016-01-01

Silicon (Si) amendment to plants can confer enhanced resistance to herbivores. In the present study, the physiological and cytological mechanisms underlying the enhanced resistance of plants with Si addition were investigated for one of the most destructive rice pests in Asian countries, the rice leaf folder, Cnaphalocrocis medinalis (Guenée). Activities of defense-related enzymes, superoxide dismutase, peroxidase, catalase, phenylalanine ammonia-lyase, and polyphenol oxidase, and concentrations of malondialdehyde and soluble protein in leaves were measured in rice plants with or without leaf folder infestation and with or without Si amendment at 0.32 g Si/kg soil. Silicon amendment significantly reduced leaf folder larval survival. Silicon addition alone did not change activities of defense-related enzymes and malondialdehyde concentration in rice leaves. With leaf folder infestation, activities of the defense-related enzymes increased and malondialdehyde concentration decreased in plants amended with Si. Soluble protein content increased with Si addition when the plants were not infested, but was reduced more in the infested plants with Si amendment than in those without Si addition. Regardless of leaf folder infestation, Si amendment significantly increased leaf Si content through increases in the number and width of silica cells. Our results show that Si addition enhances rice resistance to the leaf folder through priming the feeding stress defense system, reduction in soluble protein content and cell silicification of rice leaves. PMID:27124300

Soil microbial properties after 5 years of consecutive amendment with composted tannery sludge.

PubMed

Araujo, Ademir Sérgio Ferreira; Miranda, Ana Roberta Lima; Oliveira, Mara Lucia Jacinto; Santos, Vilma Maria; Nunes, Luís Alfredo Pinheiro Leal; Melo, Wanderley José

2015-01-01

Composting has been recognised an alternative method to tannery sludge recycling and afterwards to be used in agriculture. As the tannery sludge contains salts and chromium, the application of composted tannery sludge (CTS) should be performed carefully to minimise negative effects on soil microbial properties. Therefore, this study evaluated the effects of 5-year repeated CTS amendment on soil microbial biomass (SMB) and enzyme activities in a tropical soil. CTS was applied during 5 years at 0, 2.5, 5, 10 and 20 Mg ha(-1), and at the fifth year, the microbial biomass C (MBC) and N (MBN), basal and substrate-induced respiration (SIR), metabolic quotient (qCO₂) and dehydrogenase (DHA) and fluorescein diacetate (FDA) hydrolysis were determined in the soil samples. Soil MBC and MBN showed the highest values with the amendment of 5 Mg ha(-1) CTS. Soil respiration increased with the increase in CTS rates, while SIR showed the highest values with the amendment of 0, 2.5 and 5 Mg ha(-1) CTS. DHA activity showed the highest values with the amendment up to 2.5 Mg ha(-1), while FDA hydrolysis increased up to the rate of 5 Mg ha(-1) CTS. The results show that after 5 years of permanent amendment of CTS, soils amended with 2.5 Mg ha(-1) have SMB and enzymatic activities similar to those in unamended soil.

Organic amendments to avocado crops induce suppressiveness and influence the composition and activity of soil microbial communities.

PubMed

Bonilla, Nuria; Vida, Carmen; Martínez-Alonso, Maira; Landa, Blanca B; Gaju, Nuria; Cazorla, Francisco M; de Vicente, Antonio

2015-05-15

One of the main avocado diseases in southern Spain is white root rot caused by the fungus Rosellinia necatrix Prill. The use of organic soil amendments to enhance the suppressiveness of natural soil is an inviting approach that has successfully controlled other soilborne pathogens. This study tested the suppressive capacity of different organic amendments against R. necatrix and analyzed their effects on soil microbial communities and enzymatic activities. Two-year-old avocado trees were grown in soil treated with composted organic amendments and then used for inoculation assays. All of the organic treatments reduced disease development in comparison to unamended control soil, especially yard waste (YW) and almond shells (AS). The YW had a strong effect on microbial communities in bulk soil and produced larger population levels and diversity, higher hydrolytic activity and strong changes in the bacterial community composition of bulk soil, suggesting a mechanism of general suppression. Amendment with AS induced more subtle changes in bacterial community composition and specific enzymatic activities, with the strongest effects observed in the rhizosphere. Even if the effect was not strong, the changes caused by AS in bulk soil microbiota were related to the direct inhibition of R. necatrix by this amendment, most likely being connected to specific populations able to recolonize conducive soil after pasteurization. All of the organic amendments assayed in this study were able to suppress white root rot, although their suppressiveness appears to be mediated differentially. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

To amend the Sikes Act to promote the use of cooperative agreements under such Act for land management related to Department of Defense readiness activities and to amend title 10, United States Code, to facilitate interagency cooperation in conservation programs to avoid or reduce adverse impacts on military readiness activities.

THOMAS, 113th Congress

Rep. Bordallo, Madeleine Z. [D-GU-At Large

2013-03-12

House - 06/17/2013 Reported (Amended) by the Committee on Natural Resources. H. Rept. 113-115, Part I. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Behavior of oxyfluorfen in soils amended with different sources of organic matter. Effects on soil biology.

PubMed

Gómez, Isidoro; Rodríguez-Morgado, Bruno; Parrado, Juan; García, Carlos; Hernández, Teresa; Tejada, Manuel

2014-05-30

We performed a laboratory study on the effect of oxyfluorfen at a rate of 4lha(-1) on biological properties of a soil amended with four organic wastes (two biostimulants/biofertilizers, obtained from rice bran, RB1 and RB2; municipal solid waste, MSW; and sheep manure, SM). Soil was mixed with SM at a rate of 1%, MSW at a rate of 0.52%, RB1 at a rate of 0.39% and RB2 at a rate of 0.30%, in order to apply the same amount of organic matter to the soil. The enzymatic activities and microbial community in the soil were determined during the incubation times. The application of RB1 and RB2 to soil without oxyfluorfen increased the enzymatic activities and biodiversity, peaking at day 10 of the incubation period. This stimulation was higher in the soil amended with RB2 than in that amended with RB1. In SM and CF-amended soils, the stimulation of enzymatic activities and soil biodiversity increased during the experiment. The application of herbicide in organic-amended soils decreased the inhibition of soil enzymatic activities and soil biodiversity. Possibly the low molecular weight protein content easily assimilated by soil microorganisms and the higher fat content in the biostimulants/biofertilizers are responsible for the lower inhibition of these soil biological properties. Copyright © 2014 Elsevier B.V. All rights reserved.

15 CFR Supplement No. 3 to Part 715 - Deadlines for Submission of Declarations, No Changes Authorization Forms, Amendments for...

Code of Federal Regulations, 2013 CFR

2013-01-01

... Declarations, No Changes Authorization Forms, Amendments for Unscheduled Discrete Organic Chemical (UDOC... COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING UNSCHEDULED DISCRETE ORGANIC..., No Changes Authorization Forms, Amendments for Unscheduled Discrete Organic Chemical (UDOC...

15 CFR Supplement No. 3 to Part 715 - Deadlines for Submission of Declarations, No Changes Authorization Forms, Amendments for...

Code of Federal Regulations, 2011 CFR

2011-01-01

... Declarations, No Changes Authorization Forms, Amendments for Unscheduled Discrete Organic Chemical (UDOC... COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING UNSCHEDULED DISCRETE ORGANIC... Changes Authorization Forms, Amendments for Unscheduled Discrete Organic Chemical (UDOC) Facilities, and...

15 CFR Supplement No. 3 to Part 715 - Deadlines for Submission of Declarations, No Changes Authorization Forms, Amendments for...

Code of Federal Regulations, 2014 CFR

2014-01-01

... Declarations, No Changes Authorization Forms, Amendments for Unscheduled Discrete Organic Chemical (UDOC... COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING UNSCHEDULED DISCRETE ORGANIC..., No Changes Authorization Forms, Amendments for Unscheduled Discrete Organic Chemical (UDOC...

15 CFR Supplement No. 3 to Part 715 - Deadlines for Submission of Declarations, No Changes Authorization Forms, Amendments for...

Code of Federal Regulations, 2012 CFR

2012-01-01

... Declarations, No Changes Authorization Forms, Amendments for Unscheduled Discrete Organic Chemical (UDOC... COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING UNSCHEDULED DISCRETE ORGANIC... Changes Authorization Forms, Amendments for Unscheduled Discrete Organic Chemical (UDOC) Facilities, and...

15 CFR Supplement No. 3 to Part 715 - Deadlines for Submission of Declarations, No Changes Authorization Forms, Amendments for...

Code of Federal Regulations, 2010 CFR

2010-01-01

... Declarations, No Changes Authorization Forms, Amendments for Unscheduled Discrete Organic Chemical (UDOC... COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING UNSCHEDULED DISCRETE ORGANIC... Changes Authorization Forms, Amendments for Unscheduled Discrete Organic Chemical (UDOC) Facilities, and...

Role of CaCO3 and Charcoal Application on Organic Matter Retention in Silt-sized Aggregates

NASA Astrophysics Data System (ADS)

Berhe, A. A.; Kaiser, M.; Ghezzehei, T.; Myrold, D.; Kleber, M.

2011-12-01

The effectiveness of charcoal and calcium carbonate (CaCO3) applications to improve soil conditions has been well documented. However, their influence on the formation of silt-sized aggregates and the amount and protection of associated organic matter (OM) against microbial decomposition under differing soil mineralogical and microbiological conditions are still unknown. For sustainable management of agricultural soils, silt-sized aggregates (2-50 μm) are of particularly large importance because they store up to 60% of soil organic carbon and with mean residence times between 70 and 400 years. The objectives of this study are i) to analyze the ability of soil amendments (CaCO3, charcoal and their combined application) to increase the amount of silt-sized aggregates and associated organic matter, ii) vary soil mineral conditions to establish relevant boundary conditions for amendment-induced aggregation process, iii) to determine how amendment-induced changes in formation of silt-sized aggregates relate to microbial decomposition of OM. We set up artificial high reactive (clay: 40%, sand: 57%, SOM: 3%) and low reactive soils (clay: 10%, sand: 89%, SOM: 1%) and mixed them with charcoal (1%) and/or CaCO3 (0.2%). The samples were adjusted to a water potential of 0.3 bar using a nutrient solution and sub samples were incubated with microbial innoculum. After four months, silt-sized aggregates are separated by a combination of wet-sieving and sedimentation. We hypothesize that the relative increase in amount of silt-sized aggregates and associated OM is larger for less reactive soils than for high reactive soils because of a relative larger increase in binding agents by addition of charcoal and/or CaCO3 in less reactive soils. The effect of charcoal and/or CaCO3 application on the amount of silt-sized aggregates and associated OM is expected to increases with an increase in microbial activity. Between different treatments, we expect the incubated 'charcoal+CaCO3' combination to have the largest effect on silt-size scale aggregation processes because the amount of microbial derived cementing agents, charcoal derived functional groups containing OM, and Ca2+ ions are enhanced at the same time.

Influence of pyrolysis temperature on composted sewage sludge biochar priming effect in a loamy soil.

PubMed

Méndez, A; Tarquis, A M; Saa-Requejo, A; Guerrero, F; Gascó, G

2013-10-01

Biochar is a carbon-rich solid product obtained by the pyrolysis of organic materials. The carbon stability of biochar allows that it can be applied to soil for long-term carbon storage. This carbon stability is greatly influenced by the pyrolysis temperature and the raw material used for biochar production. The aim of the present work is to study the soil carbon sequestration after the application of biochar from sewage sludge (SL) pyrolysis at two different temperatures (400 and 600 °C). For this purpose, soil CO2 emissions were measured for 80 d in an incubation experiment after soil amendment with the SL and each biochar at a dosage of 8 wt%. Biochar reduced the CO2 emissions during incubation between 11% and 32% relative to the SL treatment. The CO2 data were fit to a dual exponential model, and the CO2 emissions were simulated at different times (1, 5 and 10 yr). Additionally, the kinetics of the CO2 evolution from SL, two biochar samples, soil and amended soil were well fit to a dual first-order kinetic model with correlation coefficients greater than 0.93. The simulation of CO2 emissions from the soil by applying the proposed double first-order kinetic model (kg CO2-C ha(-1)) showed a reduction of CO2 emissions between 301 and 932 kg CO2-C ha(-1)with respect to the direct application of raw sewage sludge after 10 yr. Copyright © 2013 Elsevier Ltd. All rights reserved.

Carbon amendment stimulates benthic nitrogen cycling during the bioremediation of particulate aquaculture waste

NASA Astrophysics Data System (ADS)

Robinson, Georgina; MacTavish, Thomas; Savage, Candida; Caldwell, Gary S.; Jones, Clifford L. W.; Probyn, Trevor; Eyre, Bradley D.; Stead, Selina M.

2018-03-01

The treatment of organic wastes remains one of the key sustainability challenges facing the growing global aquaculture industry. Bioremediation systems based on coupled bioturbation-microbial processing offer a promising route for waste management. We present, for the first time, a combined biogeochemical-molecular analysis of the short-term performance of one such system that is designed to receive nitrogen-rich particulate aquaculture wastes. Using sea cucumbers (Holothuria scabra) as a model bioturbator we provide evidence that adjusting the waste C : N from 5 : 1 to 20 : 1 promoted a shift in nitrogen cycling pathways towards the dissimilatory nitrate reduction to ammonium (DNRA), resulting in net NH4+ efflux from the sediment. The carbon amended treatment exhibited an overall net N2 uptake, whereas the control receiving only aquaculture waste exhibited net N2 production, suggesting that carbon supplementation enhanced nitrogen fixation. The higher NH4+ efflux and N2 uptake was further supported by meta-genome predictions that indicate that organic-carbon addition stimulated DNRA over denitrification. These findings indicate that carbon addition may potentially result in greater retention of nitrogen within the system; however, longer-term trials are necessary to determine whether this nitrogen retention is translated into improved sea cucumber biomass yields. Whether this truly constitutes a remediation process is open for debate as there remains the risk that any increased nitrogen retention may be temporary, with any subsequent release potentially raising the eutrophication risk. Longer and larger-scale trials are required before this approach may be validated with the complexities of the in-system nitrogen cycle being fully understood.

Review on utilization of biochar for metal-contaminated soil and sediment remediation.

PubMed

Wang, Mingming; Zhu, Yi; Cheng, Lirong; Andserson, Bruce; Zhao, Xiaohui; Wang, Dayang; Ding, Aizhong

2018-01-01

Biochar is a carbon-neutral or even carbon-negative material produced through thermal decomposition of plant- and animal-based biomass under oxygen-limited conditions. Recently, there has been an increasing interest in the application of biochar as an adsorbent, soil ameliorant and climate mitigation approach in many types of applications. Metal-contaminated soil remediation using biochar has been intensively investigated in small-scale and pilot-scale trials with obtained beneficial results and multifaceted effects. But so far, the study and application of biochar in contaminated sediment management has been very limited, and this is also a worldwide problem. Nonetheless, there is reason to believe that the same multiple benefits can also be realized with these sediments due to similar mechanisms for stabilizing contaminants. This paper provides a review on current biochar properties and its use as a sorbent/amendment for metal-contaminated soil/sediment remediation and its effect on plant growth, fauna habits as well as microorganism communities. In addition, the use of biochar as a potential strategy for contaminated sediment management is also discussed, especially as regards in-situ planning. Finally, we highlight the possibility of biochar application as an effective amendment and propose further research directions to ensure the safe and sustainable use of biochar as an amendment for remediation of contaminated soil and sediment. Copyright © 2017. Published by Elsevier B.V.

Differences in soil solution chemistry between soils amended with nanosized CuO or Cu reference materials: implications for nanotoxicity tests.

PubMed

McShane, Heather V A; Sunahara, Geoffrey I; Whalen, Joann K; Hendershot, William H

2014-07-15

Soil toxicity tests for metal oxide nanoparticles often include micrometer-sized oxide and metal salt treatments to distinguish between toxicity from nanometer-sized particles, non-nanometer-sized particles, and dissolved ions. Test result will be confounded if each chemical form has different effects on soil solution chemistry. We report on changes in soil solution chemistry over 56 days-the duration of some standard soil toxicity tests-in three soils amended with 500 mg/kg Cu as nanometer-sized CuO (nano), micrometer-sized CuO (micrometer), or Cu(NO3)2 (salt). In the CuO-amended soils, the log Cu2+ activity was initially low (minimum -9.48) and increased with time (maximum -5.20), whereas in the salt-amended soils it was initially high (maximum -4.80) and decreased with time (minimum -6.10). The Cu2+ activity in the nano-amended soils was higher than in the micrometer-amended soils for at least the first 11 days, and lower than in the salt-amended soils for at least 28 d. The pH, and dissolved Ca and Mg concentrations in the CuO-amended soils were similar, but the salt-amended soils had lower pH for at least 14 d, and higher Ca and Mg concentrations throughout the test. Soil pretreatments such as leaching and aging prior to toxicity tests are suggested.

Effect of Carbonate Matrix on δ15N Analysis Tested for Simple Bulk Combustion on Coupled Elemental Analyzer-GC-IRMS

NASA Astrophysics Data System (ADS)

Saxena, D.; Grossman, E. L.; Maupin, C. R.; Roark, B.; O'Dea, A.

2016-12-01

Nitrogen isotopes (15N/14N) have been extensively used to reconstruct trophic structure, anthropogenic nutrient loading, ecosystem dynamics, and nutrient cycling in terrestrial and marine systems. Extending similar efforts to deep time is critical to investigate sources and fluxes of nutrients in past oceans, and explore causes of biotic turnover. To test the fidelity of N-isotope analyses of biogenic carbonate samples by simple bulk combustion, we performed two sets of experiments involving varying proportions of reagent CaCO3 (0, 2, 35 mg) and three organic standards (3.7-47.2 µg) viz. USGS40 (δ15NAir = -4.52‰), USGS41 (δ15NAir = +47.57‰), and in-house standard Rice (δ15NAir = +1.18‰). At high N contents (15-47.2 µg), δ15N values for CaCO3-amended samples are consistently either 0.5‰ higher (USGS40, -4.5‰), equivalent (Rice, 1.2‰), or 0.5‰ lower (USGS41, 47.6‰) relative to unamended samples. The difference thus depends on the δ15N of the standard relative to air. With decreasing N content (10-15 µg), δ15N values for CaCO3-amended samples diverge from expected values, with 35 mg CaCO3 samples diverging at the highest N content and 0 mg CaCO3 samples at the lowest (10 µg). The latter matches the lower sample-size limit for accurate measurement under the experimental conditions. At very low sample size (3.7-10 µg), all unamended standards show decreasing δ15N with decreasing N content, presumably because of non-linearity in instrument electronics and ion source behavior. The δ15N values of amended USGS41 also decrease with decreasing N content, but those of amended USGS40 and Rice samples increase, with samples containing more CaCO3 (35 versus 2 mg) showing greater deviation from expected values. Potential causes for deviation in δ15N values with CaCO3 amendments include N2 contamination from tin capsules and reagent CaCO3, and incomplete combustion due to energy consumption during CaCO3 decomposition. While tin capsules and reagent CaCO3 provide some N background (0.07 Vs and 0.23 Vs [40 mg CaCO3] respectively), mass balance considerations suggest incomplete combustion likely caused the deviation from true values. Nevertheless, for higher N content samples reliable δ15N measurements can be made with simple bulk combustion of carbonate.

Brassica napus has a key role in the recovery of the health of soils contaminated with metals and diesel by rhizoremediation.

PubMed

Lacalle, Rafael G; Gómez-Sagasti, María T; Artetxe, Unai; Garbisu, Carlos; Becerril, José M

2018-03-15

Contaminated soils are frequently characterized by the simultaneous presence of organic and inorganic contaminants, as well as a poor biological and nutritional status. Rhizoremediation, the combined use of phytoremediation and bioremediation, has been proposed as a Gentle Remediation Option to rehabilitate multi-contaminated soils. Recently, newer techniques, such as the application of metallic nanoparticles, are being deployed in an attempt to improve traditional remediation options. In order to implement a phytomanagement strategy on calcareous alkaline peri-urban soils simultaneously contaminated with several metals and diesel, we evaluated the effectiveness of Brassica napus L., a profitable crop species, assisted with organic amendment and zero-valent iron nanoparticles (nZVI). A two-month phytotron experiment was carried out using two soils, i.e. amended and unamended with organic matter. Soils were artificially contaminated with Zn, Cu and Cd (1500, 500 and 50mgkg -1 , respectively) and diesel (6000mgkg -1 ). After one month of stabilization, soils were treated with nZVI and/or planted with B. napus. The experiment was conducted with 16 treatments resulting from the combination of the following factors: amended/unamended, contaminated/non-contaminated, planted/unplanted and nZVI/no-nZVI. Soil physicochemical characteristics and biological indicators (plant performance and soil microbial properties) were determined at several time points along the experiment. Carbonate content of soils was the crucial factor for metal immobilization and, concomitantly, reduction of metal toxicity. Organic amendment was essential to promote diesel degradation and to improve the health and biomass of B. napus. Soil microorganisms degraded preferably diesel hydrocarbons of biological origin (biodiesel). Plants had a remarkable positive impact on the activity and functional diversity of soil microbial communities. The nZVI were ineffective as soil remediation tools, but did not cause any toxicity. We concluded that rhizoremediation with B. napus combined with an organic amendment is promising for the phytomanagement of calcareous soils with mixed (metals and diesel) contamination. Copyright © 2017 Elsevier B.V. All rights reserved.

In situ remediation of chlorinated solvent-contaminated groundwater using ZVI/organic carbon amendment in China: field pilot test and full-scale application.

PubMed

Yang, Jie; Meng, Liang; Guo, Lin

2018-02-01

Chlorinated solvents in groundwater pose threats to human health and the environment due to their carcinogenesis and bioaccumulation. These problems are often more severe in developing countries such as China. Thus, methods for chlorinated solvent-contaminated groundwater remediation are urgently needed. This study presents a technique of in situ remediation via the direct-push amendment injection that enhances the reductive dechlorination of chlorinated solvents in groundwater in the low-permeability aquifer. A field-based pilot test and a following real-world, full-scale application were conducted at an active manufacturing facility in Shanghai, China. The chlorinated solvents found at the clay till site included 1,1,1-trichloroethane (1,1,1-TCA), 1,1-dichloroethane (1,1-DCA), 1,1-dichloroethylene (1,1-DCE), vinyl chloride (VC), and chloroethane (CA). A commercially available amendment (EHC ® , Peroxychem, Philadelphia, PA) combining zero-valent iron and organic carbon was used to treat the above pollutants. Pilot test results showed that direct-push EHC injection efficiently facilitated the in situ reductive remediation of groundwater contaminated with chlorinated solvents. The mean removal rates of 1,1,1-TCA, 1,1-DCA, and 1,1-DCE at 270 days post-injection were 99.6, 99.3, and 73.3%, respectively, which were obviously higher than those of VC and CA (42.3 and 37.1%, respectively). Clear decreases in oxidation-reduction potential and dissolved oxygen concentration, and increases in Fe 2+ and total organic carbon concentration, were also observed during the monitoring period. These indicate that EHC promotes the anaerobic degradation of chlorinated hydrocarbons primarily via long-term biological reductive dechlorination, with instant chemical reductive dechlorination acting as a secondary pathway. The optimal effective time of EHC injection was 0-90 days, and its radius of influence was 1.5 m. In full-scale application, the maximum concentrations of 1,1,1-TCA and 1,1-DCA in the contaminate plume fell below the relevant Dutch Intervention Values at 180 days post-injection. Moreover, the dynamics of the target pollutant concentrations mirrored those of the pilot test. Thus, we have demonstrated that the direct-push injection of EHC successfully leads to the remediation of chlorinated solvent-contaminated groundwater in a real-world scenario. The parameters determined by this study (e.g., effectiveness, injection amount, injection depth, injection pressures, and radius of influence) are applicable to other low-permeability contaminated sites where in situ remediation by enhanced reductive dechlorination is required.

Microbial utilization of rice straw and its derived biochar in a paddy soil.

PubMed

Pan, Fuxia; Li, Yaying; Chapman, Stephen James; Khan, Sardar; Yao, Huaiying

2016-07-15

The application of straw and biochar to soil has received great attention because of their potential benefits such as fertility improvement and carbon (C) sequestration. The abiotic effects of these materials on C and nitrogen (N) cycling in the soil ecosystem have been previously investigated, however, the effects of straw or its derived biochar on the soil microbial community structure and function are not well understood. For this purpose, a short-term incubation experiment was conducted using (13)C-labeled rice straw and its derived biochar ((13)C-labeled biochar) to deepen our understanding about soil microbial community dynamics and function in C sequestration and greenhouse gas emission in the acidic paddy soil amended with these materials. Regarding microbial function, biochar and straw applications increased CO2 emission in the initial stage of incubation and reached the highest level (0.52 and 3.96mgCkg(-1)soilh(-1)) at 1d and 3d after incubation, respectively. Straw amendment significantly (p<0.01) increased respiration rate, total phospholipid fatty acids (PLFAs) and (13)C-PLFA as compared to biochar amendment and the control. The amount and percent of Gram positive bacteria, fungi and actinomycetes were also significantly (p<0.05) higher in (13)C-labeled straw amended soil than the (13)C-labeled biochar amended soil. According to the (13)C data, 23 different PLFAs were derived from straw amended paddy soil, while only 17 PLFAs were derived from biochar amendments. The profile of (13)C-PLFAs derived from straw amendment was significantly (p<0.01) different from biochar amendment. The PLFAs18:1ω7c and cy17:0 (indicators of Gram negative bacteria) showed high relative abundances in the biochar amendment, while 10Me18:0, i17:0 and 18:2ω6,9c (indicators of actinomycetes, Gram positive bacteria and fungi, respectively) showed high relative abundance in the straw amendments. Our results suggest that the function, size and structure of the microbial community were strongly influenced by the substrate composition and availability. Copyright © 2016 Elsevier B.V. All rights reserved.

78 FR 52680 - Amendment to the International Traffic in Arms Regulations: Registration and Licensing of Brokers...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-26

...The Department of State is issuing this interim final rule amending the International Traffic in Arms Regulations (ITAR) relating to brokers and brokering activities and to related provisions of the ITAR. These amendments clarify registration requirements, the scope of brokering activities, prior approval requirements and exemptions, procedures for obtaining prior approval and guidance, and reporting and recordkeeping of such activities. Conforming and technical changes are made to other parts of the ITAR that affect export as well as brokering activities. The revisions contained in this rule are part of the Department of State's retrospective plan under E.O. 13563 completed on August 17, 2011.

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...

Biochar: A soil amendment worth considering

USDA-ARS?s Scientific Manuscript database

Biochar is a fine-grained, carbon enriched product created when biomass (e.g. wood waste, manures) is burned at relatively low temperatures (less than 1300oF) and under an anoxic (lack of oxygen) atmosphere. The benefits of biochar addition to soils have long since been recognized. Amazonian dark ...

Black Earths (Terra Preta): Observations of wider occurrence from natural fire

USDA-ARS?s Scientific Manuscript database

Recently, the occurrence of fertile dark-colored soils in the Amazon (Anthropogenic Dark Earths or terra preta de Indio) has been associated with prehistoric anthropogenic soil modification through long term additions of black carbon and other organic amendments from both agricultural and waste mana...

The Influence of Biochar on Soil Processes

USDA-ARS?s Scientific Manuscript database

Biochar may be a good soil amendment with the potential to sequester Carbon (C) for long periods of time. In addition, biochar added to soils could increase water infiltration and retention, increase cation exchange capacity and perhaps soil aggregation. However the effects of biochar on soil biol...

40 CFR 52.515 - Original identification of plan section.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) Amendments to Sections 8-2:702 (Definitions), 8-2:708 (Fuel Burning Particulate Emission) and 8-2:720..., submitted on December 6, 1983. (25) Plan revision, excluding the required vehicle emission inspection... Carbon Monoxide Attainment Plan consisting of an approvable vehicle emission inspection and maintenance...

Polycyclic aromatic hydrocarbons and volatile organic compounds in biochar and biochar-amended soil: A review

USDA-ARS?s Scientific Manuscript database

Residual pollutants including polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs), and carbon(aceous) nanoparticles are inevitably generated during the pyrolysis of waste biomass, and remain on the solid co-product called biochar. Such pollutants could have adverse effects on ...

Application of N-modified lignite and activated biochar to increase growth of summer wheat on nutrient-poor sandy soil

NASA Astrophysics Data System (ADS)

Schillem, Steffi; Schneider, Bernd-Uwe; Zeihser, Uwe; Hüttl, Reinhard F.

2017-04-01

Land degradation is recognized as the main environmental problem that adversely depletes soil organic carbon (SOC) and nitrogen (SON) stocks, which in turn directly affects the fertility and productivity of soils. Degraded soils and marginal lands are characterized by low fertility, poor physicochemical and biological properties and are almost free of soil organic matter (SOM), limiting their functional properties and, hence, their productivity. To enhance or restore the fertility of these soils, natural soil amendments such as biochar, lignite or humic acids can be added. A greenhouse experiment was carried out to investigate the effect of different application rates (5, 7.5, 11, 15, 28 t ha-1) of N-modified lignite (NL) incorporated in a nutrient-poor sandy soil from a recultivation site on plant growth, water use and nitrogen use efficiency of summer wheat. Additionally activated biochar (BC) was tested to see whether any differences exist between N-modified lignite and activated biochar at the same C-application rates. All variants with soil amendments displayed a much higher grain and straw yield and water use efficiency compared to the control sample. The differences were significant for the 28 t ha-1variant followed by the variant with 5 t ha-1 NL. With the 7.5 t ha-1 NL higher biomasses, water and nitrogen use efficiency could be achieved compared to the variant treated with BC at the same C-content. This study shows that even small amounts of N-modified lignite can increase growth, water and nitrogen use efficiency of summer wheat on marginal lands.

Protection of Students' Privacy Rights: The Hatch Amendment.

ERIC Educational Resources Information Center

Mesibov, Laurie

1985-01-01

Widely divergent interpretations are being made of the implementing regulations to the Hatch Amendment, which gives parents the right to inspect instructional materials and to limit their children's participation in some federally supported school programs and activities. This article briefly explains the Hatch Amendment and suggests a source of…

6 CFR 17.235 - Statutory amendments.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Statutory amendments. (a) This section, which applies to all provisions of these Title IX regulations, addresses statutory amendments to Title IX. (b) These Title IX regulations shall not apply to or preclude... Federal law. (c) For purposes of these Title IX regulations, program or activity or program means: (1) All...

75 FR 31795 - Office of Biotechnology Activities; Recombinant DNA Research: Amended Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-04

... DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health Office of Biotechnology Activities; Recombinant DNA Research: Amended Notice of Meeting ACTION: Notice of cancellation of... information. Dated: May 26, 2010. Jacqueline Corrigan-Curay, Acting Director, Office of Biotechnology...

Accelerated removal of pyrene and benzo[a]pyrene in freshwater sediments with amendment of cyanobacteria-derived organic matter.

PubMed

Yan, Zaisheng; Jiang, Helong; Li, Xiaohong; Shi, Yuan

2014-05-15

The removal of pyrene and benzo[a]pyrene (BaP) were investigated in freshwater sediments with amendment of seven different organic matters including cyanobacteria-derived organic matter (COM), plant-derived organic matter (POM), and humic substances (HS). During the 210 days of experiments, the amendment of COM or HS enhanced significantly the removal of pyrene and BaP in sediments, especially with fresh COM (FCOM) treatment much superior to HS. On the contrary, degradation of these polycyclic aromatic hydrocarbons (PAHs) was not significantly improved and even inhibited in POM-amended sediments. The first-order rate constants of pyrene and BaP degradation in the FCOM-amended sediments reached 0.00540±0.00017d(-1) and 0.00517±0.00057d(-1), respectively, and were about three and five folds of those in the control treatment. The enhanced PAHs degradation in FCOM-amended sediments was related to higher PAH-degrading bacteria number and bioavailability with a result of biostimulation and priming effect by labile carbon and high-value nutrition in FCOM. Thus, this study improved our understanding about effects of settled biomass from cyanobacterial blooms, which occurred frequently in eutrophic aquatic ecosystems, on the natural attenuation of PAHs in sediments. Furthermore, this study would also help develop a new promising approach to remediate PAH-contaminated sediments through utilization of cyanobacterial bloom biomass. Copyright © 2014 Elsevier B.V. All rights reserved.

Global warming potential of manure amended soils under rice-wheat system in the Indo-Gangetic plains

NASA Astrophysics Data System (ADS)

Bhatia, A.; Pathak, H.; Jain, N.; Singh, P. K.; Singh, A. K.

Use of organic amendments such as farmyard manure (FYM), green manure (GM) and crop residues is important to improve soil health and reduce the dependence on synthetic chemical fertilizer. However, these organic amendments also effect the emissions of greenhouse gas (GHG) from soil. Influence of different organic amendments on emissions of GHG from soil and their global warming potential (GWP) was studied in a field experiment in rice-wheat cropping system of Indo-Gangetic plains (IGP). There was 28% increase in CH 4 emissions on addition of 25% N through Sesbania GM along with urea compared to urea alone. Substitution of 100% inorganic N by organic sources lead to a 60% increase in CH 4 emissions. The carbon equivalent emission from rice-wheat systems varied between 3816 and 4886 kg C equivalent ha -1 depending upon fertilizer and organic amendment. GWP of rice-wheat system increased by 28% on full substitution of organic N by chemical N. However, the C efficiency ratios of the GM and crop residue treatments were at par with the recommended inorganic fertilizer treatment. Thus use of organic amendments along with inorganic fertilizer increases the GWP of the rice-wheat system but may improve the soil fertility status without adversely affecting the C efficiency ratio. However, the trade-off between improved yield and soil health versus GHG emissions should be taken into account while promoting the practice of farming with organic residues substitution for mineral fertilizer.

Heterogeneity of zeolite combined with biochar properties as a function of sewage sludge composting and production of nutrient-rich compost.

PubMed

Kumar Awasthi, Mukesh; Wang, Meijing; Pandey, Ashok; Chen, Hongyu; Kumar Awasthi, Sanjeev; Wang, Quan; Ren, Xiuna; Hussain Lahori, Altaf; Li, Dong-Sheng; Li, Ronghua; Zhang, Zengqiang

2017-10-01

In the present study, biochar combined with a higher dosage of zeolite (Z) and biochar (B) alone were applied as additives for dewatered fresh sewage sludge (DFSS) composting using 130-L working volume lab-scale reactors. We first observed that the addition of a mixture of B and Z to DFSS equivalent to 12%B+10% (Z-1), 15% (Z-2) and 30% (Z-3) zeolite (dry weight basis) worked synergistically as an amendment and increased the composting efficiency compared with a treatment of 12%B alone amended and a control without any amendment. In a composting reactor, the addition of B+Z may serve as a novel approach for improving DFSS composting and the quality of the end product in terms of the temperature, water-holding capacity, CO 2 emissions, electrical conductivity, water-soluble and total macro-nutrient content and phytotoxicity. The results indicated that during the thermophilic phase, dissolved organic carbon, NH 4 + -N and NO 3 - -N increased drastically in all biochar amended treatments, whereas considerably low water-soluble nutrients were observed in the control treatment throughout and at the end of the composting. Furthermore, the maturity parameters and dissolved organic carbon (DOC) indicated that compost with 12%B+15%Z became more mature and humified within 35days of DFSS composting, with the maturity parameters, such as CO 2 evolution and the concentration of NH 4 + -N in the compost, being within the permissible limits of organic farming in contrast to the control. Furthermore, at the end of composting, the addition of higher dosage of biochar (12%) alone and 12% B+Z lowered the pH by 7.15 to 7.86 and the electrical conductivity by 2.65 to 2.95mScm -1 as compared to the control, while increased the concentrations of water-soluble nutrients (gkg -1 ) including available phosphorus, sodium and potassium. In addition, greenhouse experiments demonstrated that the treatment of 150kgha -1 biochar combined with zeolite and that of 12%B alone improved the yield of Chinese cabbage (Brassica rapa chinensis L.). The highest dry weight biomass (1.41±0.12g/pot) was obtained with 12%B+15%Z amended compost. Therefore, 12%B+15%Z can be potentially applied as an amendment to improve DFSS composting. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of water additions, chemical amendments, and plants on in situ measures of nutrient bioavailability in calcareous soils of southeastern Utah, USA

USGS Publications Warehouse

Miller, M.E.; Belnap, J.; Beatty, S.W.; Webb, B.L.

2006-01-01

We used ion-exchange resin bags to investigate effects of water additions, chemical amendments, and plant presence on in situ measures of nutrient bioavailability in conjunction with a study examining soil controls of ecosystem invasion by the exotic annual grass Bromus tectorum L. At five dryland sites in southeastern Utah, USA, resin bags were buried in experimental plots randomly assigned to combinations of two watering treatments (wet and dry), four chemical-amendment treatments (KCl, MgO, CaO, and no amendment), and four plant treatments (B. tectorum alone, the perennial bunchgrass Stipa hymenoides R. & S. alone, B. tectorum and S. hymenoides together, and no plants). Resin bags were initially buried in September 1997; replaced in January, April, and June 1998; and removed at the end of the study in October 1998. When averaged across watering treatments, plots receiving KCl applications had lower resin-bag NO 3- than plots receiving no chemical amendments during three of four measurement periods-probably due to NO 3- displacement from resin bags by Cl- ions. During the January-April period, KCl application in wet plots (but not dry plots) decreased resin-bag NH 4+ and increased resin-bag NO 3- . This interaction effect likely resulted from displacement of NH 4+ from resins by K+ ions, followed by nitrification and enhanced NO 3- capture by resin bags. In plots not receiving KCl applications, resin-bag NH 4+ was higher in wet plots than in dry plots during the same period. During the January-April period, resin-bag measures for carbonate-related ions HPO 42- , Ca2+, and Mn2+ tended to be greater in the presence of B. tectorum than in the absence of B. tectorum. This trend was evident only in wet plots where B. tectorum densities were much higher than in dry plots. We attribute this pattern to the mobilization of carbonate-associated ions by root exudates of B. tectorum. These findings indicate the importance of considering potential indirect effects of soil amendments performed in conjunction with resource-limitation studies, and they suggest the need for further research concerning nutrient acquisition mechanisms of B. tectorum. ?? 2006 Springer Science+Business Media B.V.

75 FR 64785 - Corporate Credit Unions

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-20

...NCUA is issuing final amendments to its rule governing corporate credit unions. The major revisions involve corporate credit union capital, investments, asset-liability management, governance, and credit union service organization (CUSO) activities. The amendments establish a new capital scheme, including risk-based capital requirements; impose new prompt corrective action requirements; place various new limits on corporate investments; impose new asset-liability management controls; amend some corporate governance provisions; and limit a corporate CUSO to categories of services preapproved by NCUA. In addition, this rulemaking contains conforming amendments to rules governing Prompt Corrective Action (for natural person credit unions); Investments and Deposit Activities (for federal credit unions); Administrative Actions, Adjudicative Hearings, Rules of Practice and Procedure, and Investigations; and Involuntary Liquidation of Federal Credit Unions and Adjudication of Creditor Claims Involving Federally Insured Credit Unions. These amendments will strengthen individual corporates and the corporate credit union system as a whole.

Antifungal activity of food additives in vitro and as ingredients of hydroxypropyl methylcellulose-lipid edible coatings against Botrytis cinerea and Alternaria alternata on cherry tomato fruit.

PubMed

Fagundes, Cristiane; Pérez-Gago, María B; Monteiro, Alcilene R; Palou, Lluís

2013-09-16

The antifungal activity of food additives or 'generally recognized as safe' (GRAS) compounds was tested in vitro against Botrytis cinerea and Alternaria alternata. Radial mycelial growth of each pathogen was measured in PDA Petri dishes amended with food preservatives at 0.2, 1.0, or 2.0% (v/v) after 3, 5, and 7 days of incubation at 25 °C. Selected additives and concentrations were tested as antifungal ingredients of hydroxypropyl methylcellulose (HPMC)-lipid edible coatings. The curative activity of stable coatings was tested in in vivo experiments. Cherry tomatoes were artificially inoculated with the pathogens, coated by immersion about 24 h later, and incubated at 20 °C and 90% RH. Disease incidence and severity (lesion diameter) were determined after 6, 10, and 15 days of incubation and the 'area under the disease progress stairs' (AUDPS) was calculated. In general, HPMC-lipid antifungal coatings controlled black spot caused by A. alternata more effectively than gray mold caused by B. cinerea. Overall, the best results for reduction of gray mold on cherry tomato fruit were obtained with coatings containing 2.0% of potassium carbonate, ammonium phosphate, potassium bicarbonate, or ammonium carbonate, while 2.0% sodium methylparaben, sodium ethylparaben, and sodium propylparaben were the best ingredients for coatings against black rot. © 2013 Elsevier B.V. All rights reserved.

Fate and Distribution of Heavy Metals in Wastewater Irrigated Calcareous Soils

PubMed Central

Stietiya, Mohammed Hashem; Duqqah, Mohammad; Udeigwe, Theophilus; Zubi, Ruba; Ammari, Tarek

2014-01-01

Accumulation of heavy metals in Jordanian soils irrigated with treated wastewater threatens agricultural sustainability. This study was carried out to investigate the environmental fate of Zn, Ni, and Cd in calcareous soils irrigated with treated wastewater and to elucidate the impact of hydrous ferric oxide (HFO) amendment on metal redistribution among soil fractions. Results showed that sorption capacity for Zarqa River (ZR1) soil was higher than Wadi Dhuleil (WD1) soil for all metals. The order of sorption affinity for WD1 was in the decreasing order of Ni > Zn > Cd, consistent with electrostatic attraction and indication of weak association with soil constituents. Following metal addition, Zn and Ni were distributed among the carbonate and Fe/Mn oxide fractions, while Cd was distributed among the exchangeable and carbonate fractions in both soils. Amending soils with 3% HFO did not increase the concentration of metals associated with the Fe/Mn oxide fraction or impact metal redistribution. The study suggests that carbonates control the mobility and bioavailability of Zn, Ni, and Cd in these calcareous soils, even in presence of a strong adsorbent such as HFO. Thus, it can be inferred that in situ heavy metal remediation of these highly calcareous soils using iron oxide compounds could be ineffective. PMID:24723833

Biochar increased water holding capacity but accelerated organic carbon leaching from a sloping farmland soil in China.

PubMed

Liu, Chen; Wang, Honglan; Tang, Xiangyu; Guan, Zhuo; Reid, Brian J; Rajapaksha, Anushka Upamali; Ok, Yong Sik; Sun, Hui

2016-01-01

A hydrologically contained field study, to assess biochar (produced from mixed crop straws) influence upon soil hydraulic properties and dissolved organic carbon (DOC) leaching, was conducted on a loamy soil (entisol). The soil, noted for its low plant-available water and low soil organic matter, is the most important arable soil type in the upper reaches of the Yangtze River catchment, China. Pore size distribution characterization (by N2 adsorption, mercury intrusion, and water retention) showed that the biochar had a tri-modal pore size distribution. This included pores with diameters in the range of 0.1-10 μm that can retain plant-available water. Comparison of soil water retention curves between the control (0) and the biochar plots (16 t ha(-1) on dry weight basis) demonstrated biochar amendment to increase soil water holding capacity. However, significant increases in DOC concentration of soil pore water in both the plough layer and the undisturbed subsoil layer were observed in the biochar-amended plots. An increased loss of DOC relative to the control was observed upon rainfall events. Measurements of excitation-emission matrix (EEM) fluorescence indicated the DOC increment originated primarily from the organic carbon pool in the soil that became more soluble following biochar incorporation.

Removal of triclosan in nitrifying activated sludge: effects of ammonia amendment and bioaugmentation.

PubMed

Lee, Do Gyun; Cho, Kun-Ching; Chu, Kung-Hui

2015-04-01

This study investigated two possible strategies, increasing ammonia oxidation activity and bioaugmenting with triclosan-degrader Sphingopyxis strain KCY1, to enhance triclosan removal in nitrifying activated sludge (NAS). Triclosan (2 mg L(-1)) was removed within 96-h in NAS bioreactors amended with 5, 25 and 75 mg L(-1) of ammonium (NH4-N). The fastest triclosan removal was observed in 25 mg NH4-NL(-1) amended-bioreactors where high ammonia oxidation occurred. Inhibition of ammonia oxidation and slower triclosan removal were observed in 75 mg NH4-NL(-1) amended-bioreactors. Triclosan removal was correlated to the molar ratio of the amount of nitrate produced to the amount of ammonium removed. Bioaugmentation with strain KCY1 did not enhance triclosan removal in the bioreactors with active ammonia oxidation. Approximately 36-42% and 59% of triclosan added were removed within 24-h by ammonia-oxidizing bacteria and unknown triclosan-degrading heterotrophs, respectively. The results suggested that increasing ammonia oxidation activity can be an effective strategy to enhance triclosan removal in NAS. Copyright © 2015 Elsevier Ltd. All rights reserved.

Reactive and recoverable sorbents for halogenated organic compound remediation in sediments

NASA Astrophysics Data System (ADS)

Werner, David; Taggalou, Villy; Kordulis, Christos; Dolfing, Jan; Karapanagioti, Hrissi K.

2013-04-01

Activated carbon (AC) has been proposed as a sediment amendment for aquatic systems polluted with hydrophobic organic compounds. AC acts as a strong binding agent that lowers the pollutant concentration and thus, its toxicity. A draw back of this in-situ remediation method is that although the pollutant will remain non-bioavailable for many years being sorbed into AC, it actually stays in the system. A reactive sorbent, a sorbent that would, at the same time, facilitate the degradation of the pollutant, would be better accepted by the public or the regulators than AC amendment. So far, catalysts supported on AC with zero valent iron and a reactive metal have been proposed for the dechlorination of chlorinated organic compounds. These reactive metals are usually expensive or toxic and thus, their addition to the environment is not desirable. In the present study, activated carbon modified with reduced iron(AC/Fe) is tested in batch systems in the presence of sediment and DDT sorbed on polyethylene sheets. The batch systems are equilibrated for different contact times. Then, the DDT remaining in the polyethylene sheets is quantified along with DDD produced due to the dechlorination of DDT. A small percentage of DDT is degraded to DDD in the systems containing the AC/Fe material. No degradation of DDT is observed in the control systems containing the pollutant and the sediment or the pollutant, the sediment and AC. Thus, the addition of AC/Fe to the sediment with the DDT is enough to cause the dechlorination of DDT. At the end of the experiments, a magnet rod is used to recover the AC/Fe material from the batches with the sediment. An average recovery of 83% is achieved. This is a high percentage suggesting that the material can be easily recovered. Some drawbacks of the material preparation method are identified after the composite material characterization. For example, the AC/Fe surface area is decreased with the material preparation compared to the initial surface area of the AC. This fact results in decrease of the sorption ability of the AC/Fe material compared to that of the AC. At the same time, more DDT degradation might be achievable by increasing the AC/Fe dosage from the 1% weight used in this study that is lower than commonly used for sediment amendments. More research is necessary to optimize the material preparation and properties.

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.

Dissolved organic matter dynamic and resident microbiota evolution in soil amended with fresh and composted olive mill wastes

NASA Astrophysics Data System (ADS)

Gigliotti, Giovanni; Massaccesi, Luisa; Federici, Ermanno; Fidati, Laura; Nasini, Luigi; Proietti, Primo

2013-04-01

The disposal of olive mill wastes represents a problem of environmental relevance particularly in the Mediterranean countries where olive oil is mostly produced. Among the several valorisation and recycling methods proposed, interesting for its operational simplicity and convenience is land spreading, either directly or after composting. However, the agriculture use of the water-saturated husk produced by the new two-phase oil extraction systems may be hampered by its consistency and its high content of phenolic compounds, which may finally lead to phytotoxicity. Humid husk may indeed modify the dynamic of soil organic matter (SOM) and the structure and function of microbial communities. On the other hand, organic amendments are known to positively affect SOM fractions, particularly by increasing the concentration and quality of dissolved organic matter (DOM), which may eventually lead to an increase in microbial activity. The aim of this work was to investigate, during a 90-day field trial, the modifications in soil DOM composition and the effects on the soil microbiota induced by a humid husk, obtained from a new generation two-phase oil extraction plant, spread in an olive orchard either as a fresh amendment or after a composting process. With respect to the control, the soil amended with either fresh or composted husk showed an increase in water extractable organic carbon (WEOC). Interestingly, while during the first 30 days the soil amended with the composted husk showed a WEOC content higher than the one amended with the fresh husk, after that time only in the latter the WEOC remained significantly higher than in the control. The total content of phenolic compounds showed a similar trend, with the only difference that their concentration in the soil amended with both treatments remained higher than the control for the entire trial. Similarly, both treatments induced an increase in soil reducing sugars, with an higher effect observed in the soil amended with the composted husk. FT-IR spectra and SUVA254 data confirmed the changes in DOM composition caused by the amendments. Denaturing gradient gel electrophoresis (DGGE) analyses of 16S and 18S rRNA genes was used to characterize the microbiota in both amendments and soils. Interestingly, the DGGE profiles changed after composting the humid husk, indicating how the organic matter transformations occurring during this process profoundly altered the microbial communities of the OMW. Soil bacterial communities were very complex and presented a high species richness throughout the entire trial. In particular, the fresh and the composted husk appeared to have only a slight effect on the bacterial community structure. This effect was observed only during the first 60 days, while after 90 days no differences with the control plot were present. On the contrary, the fungal communities presented a lower biodiversity and more variable DGGE profiles than the bacterial communities. Both treatments clearly altered the structure of the soil fungal community throughout the entire trial. Interestingly, the fungal communities profiles were different when the fresh or the composted husk was used, with the former showing more profound and stable effects.

Enhancing rain garden design to promote nitrate removal: testing a media carbon amendment.

EPA Science Inventory

Rain gardens effectively remove some stressors from stormwater, in particular heavy metals, phosphorus, and oil and grease, but in most cases they show much smaller removal rates of nitrate. This is likely due to the high sand and low organic matter content specified for rain ga...

Biochar: What is the future for industrial production and world usage?

USDA-ARS?s Scientific Manuscript database

Biochar has gained world attention as a soil amendment to increase carbon sequestration, improve fertility levels and bolster soil water retention. Unfortunately, the amount of biochar needed for field application rates to achieve these results can be in the tons per hectare range. There is concer...

Biochar and soil properties affecting microbial transport through biochar-amended soils

USDA-ARS?s Scientific Manuscript database

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. We have recently conducted a series of experiments t...

Author Correction: Ultrahard carbon film from epitaxial two-layer graphene.

PubMed

Gao, Yang; Cao, Tengfei; Cellini, Filippo; Berger, Claire; de Heer, Walter A; Tosatti, Erio; Riedo, Elisa; Bongiorno, Angelo

2018-05-21

In the version of this Article originally published, the second affiliation for Walter A. de Heer had not been included; it should be 'TICNN, Tianjin University, Tianjin, China'. This has now been added and the numbering of subsequent affiliations amended accordingly in all versions of the Article.

77 FR 3211 - Approval and Promulgation of Air Quality Implementation Plans; Delaware; Amendments to the...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-23

... Emissions From Industrial Boilers and Process Heaters at Petroleum Refineries AGENCY: Environmental... that establishes controls for nitrogen oxides (NO X ) emissions from industrial boilers and process... carbon monoxide (CO) boiler at the Delaware City Refinery and providing for a facility-wide NOx emission...

75 FR 10546 - Shipping Coordinating Committee; Notice of Committee Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-08

... centre --Explanatory notes for the application of the safe return to port requirements --Recommendation... --Amendments to chapter II-2 related to the releasing controls and means of escape for spaces protected by fixed carbon dioxide systems --Means of escape from machinery spaces --Review of fire protection for on...

RESPONSE OF TALL FESCUE, BUSH BEAN, AND MAIZE TO CHROME TANNERY SLUDGE IN SOILS

EPA Science Inventory

Tannery sludge was compared with commercial nitrogen fertiliser to investigate its potential use as an alternative to commercial fertiliser. Soils containing 38% and 7% organic carbon and with nitrogen contents of 1-3% and 0-2%, respectively, were amended with either commercial N...

40 CFR 98.166 - Data reporting requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... CO2 collected and transferred off site in either gas, liquid, or solid forms, following the... off site in either gas, liquid, or solid forms (kg carbon). [74 FR 56374, Oct. 30, 2009, as amended at... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Hydrogen Production § 98.166 Data reporting requirements. In...

40 CFR 98.166 - Data reporting requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... CO2 collected and transferred off site in either gas, liquid, or solid forms, following the... off site in either gas, liquid, or solid forms (kg carbon). [74 FR 56374, Oct. 30, 2009, as amended at... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Hydrogen Production § 98.166 Data reporting requirements. In...