Prediction of anaerobic biodegradability and bioaccessibility of municipal sludge by coupling sequential extractions with fluorescence spectroscopy: towards ADM1 variables characterization.

PubMed

Jimenez, Julie; Gonidec, Estelle; Cacho Rivero, Jesús Andrés; Latrille, Eric; Vedrenne, Fabien; Steyer, Jean-Philippe

2014-03-01

Advanced dynamic anaerobic digestion models, such as ADM1, require both detailed organic matter characterisation and intimate knowledge of the involved metabolic pathways. In the current study, a methodology for municipal sludge characterization is investigated to describe two key parameters: biodegradability and bioaccessibility of organic matter. The methodology is based on coupling sequential chemical extractions with 3D fluorescence spectroscopy. The use of increasingly strong solvents reveals different levels of organic matter accessibility and the spectroscopy measurement leads to a detailed characterisation of the organic matter. The results obtained from testing 52 municipal sludge samples (primary, secondary, digested and thermally treated) showed a successful correlation with sludge biodegradability and bioaccessibility. The two parameters, traditionally obtained through the biochemical methane potential (BMP) lab tests, are now obtain in only 5 days compared to the 30-60 days usually required. Experimental data, obtained from two different laboratory scale reactors, were used to validate the ADM1 model. The proposed approach showed a strong application potential for reactor design and advanced control of anaerobic digestion processes. Copyright © 2013 Elsevier Ltd. All rights reserved.

Anthropogenic impacts on the optical characteristics and biodegradability of dissolved and particulate organic matter in the Han River watershed, South Korea

NASA Astrophysics Data System (ADS)

Shirina Begum, Most; Jin, Hyojin; Yoon, Tae Kyung; Park, Ji-Hyung

2016-04-01

To understand how anthropogenic perturbations such as dams and pollution modify the chemical characteristics and biological transformations of riverine organic matter during transit through urbanized watersheds, we compared the optical characteristics and biodegradability of dissolved organic matter (DOM) and particulate organic matter (POM) along different reaches and urban tributary streams of the Han River watershed during short-term incubations. Laboratory incubations were conducted for 5-7 days at 20-25 oC with filtered or unfiltered water samples collected from up-, mid-, and downstream reaches with different levels of anthropogenic perturbations and three urban streams along the downstream reach that receive effluents from waste water treatment facilities in the metropolitan Seoul. Optical parameters such as ultraviolet absorbance at 254 nm, absorption coefficients at 254 nm and 350 nm, fluorescence index, humic-like fluorescence, microbial humic-like fluorescence, and protein-like fluorescence, and spectral slope at 350-400 nm were significantly correlated with increasing concentration of biodegradable dissolved organic carbon (BDOC) in filtered and unfiltered sample along the Han River up-, mid-, down-, and urban streams. The concentrations of BDOC in the urban streams were 6-12 times higher than in the filtered and unfiltered main-stem river samples, with significantly higher values in presence of POM in the unfiltered samples than in the filtered samples. In a separate 5-day incubation experiment with the unfiltered water sample from a downstream location of the Han River and its urban tributary water in isolation or mixed , the rate of concurrent biodegradation of both DOM and POM, as measured by the cumulative rate of CO2 production, was higher in the mixture than the average rate of the separately incubated samples, indicating the priming effect of mixed organic materials on the biodegradation of allochthonous organic materials from the other site. Greater amounts of CO2 were produced in all the samples than could be explained by BDOC alone, indicating the role of POM as a source of CO2. Faster and more intense changes in the consumed or produced components detected in the differential images between the fluorescence excitation emission matrices collected at intervals also suggested activated organic matter processing and CO2 production upon mixing the mainstem and tributary organic matter. Overall results suggest that dams and urban water pollution leave idiosyncratic imprints in the optical characteristics of DOM along waterways of the dammed and urbanized watershed and that inputs of anthropogenic organic materials via urban tributary streams can exert a strong priming effect on the biodegradation of both DOM and POM downstream.

Assessment of anaerobic biodegradability of five different solid organic wastes

NASA Astrophysics Data System (ADS)

Kristanto, Gabriel Andari; Asaloei, Huinny

2017-03-01

The concept of waste to energy emerges as an alternative solution to increasing waste generation and energy crisis. In the waste to energy concept, waste will be used to produce renewable energy through thermochemical, biochemical, and physiochemical processes. In an anaerobic digester, organic matter brake-down due to anaerobic bacteria produces methane gas as energy source. The organic waste break-down is affected by various characteristics of waste components, such as organic matter content (C, N, O, H, P), solid contents (TS and VS), nutrients ratio (C/N), and pH. This research aims to analyze biodegradability and potential methane production (CH4) from organic waste largely available in Indonesia. Five solid wastes comprised of fecal sludge, cow rumen, goat farm waste, traditional market waste, and tofu dregs were analyzed which showed tofu dregs as waste with the highest rate of biodegradability compared to others since the tofu dregs do not contain any inhibitor which is lignin, have 2.7%VS, 14 C/N ratios and 97.3% organic matter. The highest cumulative methane production known as Biochemical Methane Potential was achieved by tofu dregs with volume of 77 ml during 30-day experiment which then followed by cow rumen, goat farm waste, and traditional market waste. Subsequently, methane productions were calculated through percentage of COD reduction, which showed the efficiency of 99.1% that indicates complete conversion of the high organic matter into methane.

A stoichiometric organic matter decomposition model in a chemostat culture.

PubMed

Kong, Jude D; Salceanu, Paul; Wang, Hao

2018-02-01

Biodegradation, the disintegration of organic matter by microorganism, is essential for the cycling of environmental organic matter. Understanding and predicting the dynamics of this biodegradation have increasingly gained attention from the industries and government regulators. Since changes in environmental organic matter are strenuous to measure, mathematical models are essential in understanding and predicting the dynamics of organic matters. Empirical evidence suggests that grazers' preying activity on microorganism helps to facilitate biodegradation. In this paper, we formulate and investigate a stoichiometry-based organic matter decomposition model in a chemostat culture that incorporates the dynamics of grazers. We determine the criteria for the uniform persistence and extinction of the species and chemicals. Our results show that (1) if at the unique internal steady state, the per capita growth rate of bacteria is greater than the sum of the bacteria's death and dilution rates, then the bacteria will persist uniformly; (2) if in addition to this, (a) the grazers' per capita growth rate is greater than the sum of the dilution rate and grazers' death rate, and (b) the death rate of bacteria is less than some threshold, then the grazers will persist uniformly. These conditions can be achieved simultaneously if there are sufficient resources in the feed bottle. As opposed to the microcosm decomposition models' results, in a chemostat culture, chemicals always persist. Besides the transcritical bifurcation observed in microcosm models, our chemostat model exhibits Hopf bifurcation and Rosenzweig's paradox of enrichment phenomenon. Our sensitivity analysis suggests that the most effective way to facilitate degradation is to decrease the dilution rate.

Contribution of microorganisms to non-extractable residue formation from biodegradable organic contaminants in soil

NASA Astrophysics Data System (ADS)

Nowak, K. M.; Girardi, C.; Miltner, A.; Schäffer, A.; Kästner, M.

2012-04-01

Biodegradation of organic contaminants in soil is actually understood as their transformation into various primary metabolites, microbial biomass, mineralisation products and non-extractable residues (NER). NER are generally considered to be composed of parent compounds or primary metabolites with hazardous potential. Up to date, however, their chemical composition remains still unclear. Studies on NER formation are limited to quantitative analyses in soils or to simple humic acids-contaminant systems. However, in the case of biodegradable organic compounds, NER may also contain microbial biomass components, e.g. fatty acids (FA) and amino acids (AA). After cell death, these biomolecules are incorporated into soil organic matter (SOM) and stabilised, ultimately forming biogenic residues which are not any more extractable. We investigated the incorporation of the 13C-label into FA and AA and their fate during biodegradation experiments in soil with isotope-labelled 2,4-dichlorophenoxyacetic acid (13C6-2,4-D) and ibuprofen (13C6-ibu) as model organic contaminants. Our study proved for the first time that nearly all NER formed from 13C6-2,4-D and 13C6-ibu in soil derived from harmless microbial biomass components stabilised in SOM. 13C-FA and 13C-AA contents in the living microbial biomass fraction decreased over time and these components were continuously incorporated into the non-living SOM pool in biotic experiments with 13C6-2,4-D and 13C6-ibu. The 13C-AA in the non-living SOM were surprisingly stable from day 32 (13C6-2,4-D) and 58 (13C6-ibu) until the end of incubation. We also studied the transformation of 13C6-2,4-D and 13C6-ibu into NER in the abiotic soil experiments. In these experiments, the total NER contents were much lower than in the corresponding biotic experiments. The absence of labelled biomolecules in the NER fraction in abiotic soils demonstrated that they consist of the potentially hazardous parent compounds and / or their metabolites. Biogenic residue formation is relevant during biodegradation of organic contaminants, whereas abiotic NER are formed from the non-biodegraded residual contaminants. Abiotic NER and biogenic residue formation are competitive processes and do not occur in a similar extent. In the biotic treatment, the rapid mineralisation of an organic compound reduces the extent of abiotic NER formation via physico-chemical interactions between a parent compound and / or its primary metabolites with SOM. Therefore, in order to properly assess the potential risks of a target contaminant in soil to humans and the environment, it is necessary to distinguish between abiotic NER and biogenic residue formation in the mass balances of contaminants.

Long-term monitoring and prediction for settlement and composition of refuse in Shanghai Laogang Municipal Landfill.

PubMed

Jiangying, Liu; Dimin, Xu; Youcai, Zhao; Shaowei, Chen; Guojian, Li; Qi, Zhou

2004-09-01

Parameters about composition of refuse such as mass percentage of biodegradable matter, volatile solid, organic carbon, cellulose, total sugar, and settlement were monitored and analyzed in a large-scale experimental unit. The empirical formulas between composition and refuse age were established in terms of the data obtained from the experimental unit and verified by comparing with the corresponding parameters of refuse in the closed landfill units from 1991 until 1994 in the Shanghai Laogang Municipal Landfill. Furthermore, the long-term prediction for the composition of refuse was made, and it was predicted that the half-life is 7 to 11 years for biodegradable matter, 9 to 12 years for organic carbon or volatile solid, 7 to 16 years for cellulose, and 4 to 6 years for total sugar. In addition, a mathematical model, based on the mechanism of refuse biodegradation in the landfill, was developed to simulate the relationship between the settlement and the refuse age and manifests the secondary settlement potential. The mathematical model was proved not only to be reliable but also should be accurate for predicting the settlement of the landfill. The secondary settlement, which mainly results from the slow and gradual biodegradation of refuse, is linear with respect to the exponent of refuse age. Finally, according to the settlement model and empirical biodegradation formulas, it may be predicted that, 79.4% of biodegradable matter, 92.9% of total sugar, 72.7% of volatile solid and organic carbon, and 73.1% of cellulose will be biodegraded and that 79% of the maximum secondary settlement potential will occur before the Shanghai Laogang Municipal Landfill is in a high stabilization situation, i.e., approximately 21 years after final closure.

Jellyfish Lake, Palau: early diagenesis of organic matter in sediments of an anoxic marine lake

USGS Publications Warehouse

Orem, W.H.; Burnett, W.C.; Landing, W.M.; Lyons, W.B.; Showers, W.

1991-01-01

The major postdepositional change in the sedimentary organic matter is carbohydrate biodegradation. Lignin and aliphatic substances are preserved in the sediments. Dissolved organic matter in pore waters is primarily composed of carbohydrates, reflecting the degradation of sedimentary carbohydrates. Rate constants for organic carbon degradation and sulfate reduction in sediments of the lake are about 10?? lower than in other anoxic sediments. This may reflect the vascular plant source and partly degraded nature of the organic matter reaching the sediments of the lake. -from Authors

Application of TAM III to study sensitivity of soil organic matter degradation to temperature

NASA Astrophysics Data System (ADS)

Vikegard, Peter; Barros, Nieves; Piñeiro, Verónica

2014-05-01

Traditionally, studies of soil biodegradation are based on CO2 dissipation rates. CO2 is a product of aerobic degradation of labile organic substrates like carbohydrates. That limits the biodegradation concept to just one of the soil organic matter fractions. This feature is responsible for some problems to settle the concept of soil organic matter (SOM) recalcitrance and for controversial results defining sensitivity of SOM to temperature. SOM consists of highly complex macromolecules constituted by fractions with different chemical nature and redox state affecting the chemical nature of biodegradation processes. Biodegradation of fractions more reduced than carbohydrates take place through metabolic pathways that dissipate less CO2 than carbohydrate respiration, that may not dissipate CO2, or that even may uptake CO2. These compounds can be considered more recalcitrant and with lower turnover times than labile SOM just because they are degraded at lower CO2 rates that may be just a consequence of the metabolic path. Nevertheless, decomposition of every kind of organic substrate always releases heat. For this reason, the measurement of the heat rate by calorimetry yields a more realistic measurement of the biodegradation of the SOM continuum. TAM III is one of the most recent calorimeters designed for directly measuring in real time the heat rate associated with any degradation process. It is designed as a multichannel system allowing the concomitant measurement of to up 24 samples at isothermal conditions or through a temperature scanning mode from 18 to 100ºC, allowing the continous measure of any sample at controlled non-isothermal conditions. The temperature scanning mode was tested in several soil samples collected at different depths to study their sensitivity to temperature changes from 18 to 35 ºC calculating the Q10 and the activation energy (EA) by the Arrhenius equation. It was attempted to associate the obtained EA values with the soil thermal properties determined by differential scanning calorimetry and thermogravimetric analysis. The EA values obtained ranged from -30 to -48 kJ/mol increasing with soil depth and with higher heat of combustion values of the samples obtained by DSC, suggesting that increased SOM recalcitrance involves higher investment of energy by the microbial population to degrade SOM. The calorimetrically determined Q10 values were observed to decrease with soil depth and higher heat of combustión, supporting the hypothesis, as given by different authors, that higher SOM recalcitrance can be associated with a decreased sensitivity to temperature as in agreement with the increasing trend of the activation energy

Effects of effluent organic matter characteristics on the removal of bulk organic matter and selected pharmaceutically active compounds during managed aquifer recharge: Column study

NASA Astrophysics Data System (ADS)

Maeng, Sung Kyu; Sharma, Saroj K.; Abel, Chol D. T.; Magic-Knezev, Aleksandra; Song, Kyung-Guen; Amy, Gary L.

2012-10-01

Soil column experiments were conducted to investigate the effects of effluent organic matter (EfOM) characteristics on the removal of bulk organic matter (OM) and pharmaceutically active compounds (PhACs) during managed aquifer recharge (MAR) treatment processes. The fate of bulk OM and PhACs during an MAR is important to assess post-treatment requirements. Biodegradable OM from EfOM, originating from biological wastewater treatment, was effectively removed during soil passage. Based on a fluorescence excitation-emission matrix (F-EEM) analysis of wastewater effluent-dominated (WWE-dom) surface water (SW), protein-like substances, i.e., biopolymers, were removed more favorably than fluorescent humic-like substances under oxic compared to anoxic conditions. However, there was no preferential removal of biopolymers or humic substances, determined as dissolved organic carbon (DOC) observed via liquid chromatography with online organic carbon detection (LC-OCD) analysis. Most of the selected PhACs exhibited removal efficiencies of greater than 90% in both SW and WWE-dom SW. However, the removal efficiencies of bezafibrate, diclofenac and gemfibrozil were relatively low in WWE-dom SW, which contained more biodegradable OM than did SW (copiotrophic metabolism). Based on this study, low biodegradable fractions such as humic substances in MR may have enhanced the degradation of diclofenac, gemfibrozil and bezafibrate by inducing an oligotrophic microbial community via long term starvation. Both carbamazepine and clofibric acid showed persistent behaviors and were not influenced by EfOM.

Arsenic Speciation and Extraction and the Significance of Biodegradable Acid on Arsenic Removal—An Approach for Remediation of Arsenic-Contaminated Soil

PubMed Central

Nguyen Van, Thinh; Osanai, Yasuhito; Do Nguyen, Hai; Kurosawa, Kiyoshi

2017-01-01

A series of arsenic remediation tests were conducted using a washing method with biodegradable organic acids, including oxalic, citric and ascorbic acids. Approximately 80% of the arsenic in one sample was removed under the effect of the ascorbic and oxalic acid combination, which was roughly twice higher than the effectiveness of the ascorbic and citric acid combination under the same conditions. The soils treated using biodegradable acids had low remaining concentrations of arsenic that are primarily contained in the crystalline iron oxides and organic matter fractions. The close correlation between extracted arsenic and extracted iron/aluminum suggested that arsenic was removed via the dissolution of Fe/Al oxides in soils. The fractionation of arsenic in four contaminated soils was investigated using a modified sequential extraction method. Regarding fractionation, we found that most of the soil contained high proportions of arsenic (As) in exchangeable fractions with phosphorus, amorphous oxides, and crystalline iron oxides, while a small amount of the arsenic fraction was organic matter-bound. This study indicated that biodegradable organic acids can be considered as a means for arsenic-contaminated soil remediation.

Discrimination in Degradability of Soil Pyrogenic Organic Matter Follows a Return-On-Energy-Investment Principle.

PubMed

Harvey, Omar R; Myers-Pigg, Allison N; Kuo, Li-Jung; Singh, Bhupinder Pal; Kuehn, Kevin A; Louchouarn, Patrick

2016-08-16

A fundamental understanding of biodegradability is central to elucidating the role(s) of pyrogenic organic matter (PyOM) in biogeochemical cycles. Since microbial community and ecosystem dynamics are driven by net energy flows, then a quantitative assessment of energy value versus energy requirement for oxidation of PyOM should yield important insights into their biodegradability. We used bomb calorimetry, stepwise isothermal thermogravimetric analysis (isoTGA), and 5-year in situ bidegradation data to develop energy-biodegradability relationships for a suite of plant- and manure-derived PyOM (n = 10). The net energy value (ΔE) for PyOM was between 4.0 and 175 kJ mol(-1); with manure-derived PyOM having the highest ΔE. Thermal-oxidation activation energy (Ea) requirements ranged from 51 to 125 kJ mol(-1), with wood-derived PyOM having the highest Ea requirements. We propose a return-on-investment (ROI) parameter (ΔE/Ea) for differentiating short-to-medium term biodegradability of PyOM and deciphering if biodegradation will most likely proceed via cometabolism (ROI < 1) or direct metabolism (ROI ≥ 1). The ROI-biodegradability relationship was sigmoidal with higher biodegradability associated with PyOM of higher ROI; indicating that microbes exhibit a higher preference for "high investment value" PyOM.

Treatability and characterization of Natural Organic Matter (NOM) in South African waters using newly developed methods

NASA Astrophysics Data System (ADS)

Nkambule, T. I.; Krause, R. W. M.; Haarhoff, J.; Mamba, B. B.

Managing the removal of Natural Organic Matter (NOM) or problematic components from water has become increasingly important. NOM is a heterogeneous mixture of organic compounds of human origin and derived from plant and microbial residues. The inadequate removal of NOM has a bearing on the capacity of the other treatment processes to remove organic micro-pollutants or inorganic species that may be present in the water. In addition the action of certain disinfection processes has been shown to lead to the formation of harmful disinfection by-products (DBPs). Owing to the complexity, in composition and structure, of NOM, the techniques currently employed for its characterization have a number of limitations, both in terms of quantification and removal of the NOM within short periods of time. The dissolved organic carbon (DOC), biodegradable dissolved organic carbon (BDOC) and Fluorescence Emission Excitation Matrices (FEEM) were used to characterize NOM from various water samples collected around South Africa. Characterization results gave an indication of the character of NOM present in all the water samples. FEEM and UV-Vis results indicated that most of the water samples were aromatic in nature, since they had high hydrophobic and humic acid-like materials content. Generally, the characterization data indicated a varying composition of NOM amongst the various sampling points. The polarity rapid assessment method (PRAM) was then employed as a rapid NOM characterization tool. The characterization under PRAM is based on preferential adsorption of dissolved organic matter (DOM) fractions onto solid phase extraction (SPE) sorbents. The PRAM also allows the separation of DOM into fractions by polarity, hence reducing the molecular heterogeneity of NOM and thus aiding the removal of specific NOM fractions from water. The PRAM provided a quick characterization of the NOM character. However, DOC quantification by the PRAM analysis was hindered by excessive carbon leaching from the SPE cartridges. The BDOC method of analysis is based on the bacteria fixed on the biologically active sand and gives a ratio of the biodegradable NOM versus the non-biodegradable NOM. For the BDOC analysis, the percentage DOC removal for the samples ranged from 12% to 61%.

Indigenous microbes survive in situ ozonation improving biodegradation of dissolved organic matter in aged oil sands process-affected waters.

PubMed

Brown, Lisa D; Pérez-Estrada, Leonidas; Wang, Nan; El-Din, Mohamed Gamal; Martin, Jonathan W; Fedorak, Phillip M; Ulrich, Ania C

2013-11-01

The oil sands industry faces significant challenges in developing effective remediation technologies for process-affected water stored in tailings ponds. Naphthenic acids, a complex mixture of cycloaliphatic carboxylic acids, have been of particular concern because they concentrate in tailings ponds and are a component of the acutely toxic fraction of process water. Ozone treatment has been demonstrated as an effective means of rapidly degrading naphthenic acids, reducing process water toxicity, and increasing its biodegradability following seeding with the endogenous process water bacteria. This study is the first to examine subsequent in situ biodegradation following ozone pretreatment. Two aged oil sands process-affected waters from experimental reclamation tailings ponds were ozonated to reduce the dissolved organic carbon, to which naphthenic acids contributed minimally (<1mgL(-1)). Treatment with an ozone dose of 50mgL(-1) improved the 84d biodegradability of remaining dissolved organic carbon during subsequent aerobic incubation (11-13mgL(-1) removed from aged process-affected waters versus 5mgL(-1) when not pretreated with ozone). The ozone-treated indigenous microbial communities were as capable of degrading organic matter as the same community not exposed to ozone. This supports ozonation coupled with biodegradation as an effective and feasible treatment option. Copyright © 2013 Elsevier Ltd. All rights reserved.

Fractions and biodegradability of dissolved organic matter derived from different composts.

PubMed

Wei, Zimin; Zhang, Xu; Wei, Yuquan; Wen, Xin; Shi, Jianhong; Wu, Junqiu; Zhao, Yue; Xi, Beidou

2014-06-01

An experiment was conducted to determine the fractions of molecular weights (MW) and the biodegradability of dissolved organic matter (DOM) in mature composts derived from dairy cattle manure (DCM), kitchen waste (KW), cabbage waste (CW), tomato stem waste (TSW), municipal solid waste (MSW), green waste (GW), chicken manure (CM), sludge (S), and mushroom culture waste (MCW). There were distinct differences in the concentration and MW fractions of DOM, and the two measures were correlated. Fraction MW>5kDa was the major component of DOM in all mature composts. Determined 5day biochemical oxygen demand (BOD5) of DOM was correlated to the concentration of DOM and all MW fractions except MW>5kDa, indicating that the biodegradability of DOM was a function of the content and proportion of fraction MW<5kDa. This study suggests that the amount and distribution of low MW fractions affect DOM biodegradability. Copyright © 2014 Elsevier Ltd. All rights reserved.

Discrimination in Degradability of Soil Pyrogenic Organic Matter Follows a Return-On-Energy-Investment Principle

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

Harvey, Omar R.; Myers-Pigg, Allison N.; Kuo, Li-Jung

A fundamental understanding of biodegradability is central to elucidating the role(s) of pyrogenic organic matter (PyOM) in biogeochemical cycles. Since microbial community and ecosystem dynamics are driven by net energy flows, then a quantitative assessment of energy value versus energy requirement for oxidation of PyOM should yield important insights into their biodegradability. We used bomb calorimetry, step-wise isothermal thermogravimetric analysis (isoTGA) and 5-year in-situ bidegradation data, to develop energy-biodegradability relationships for a suite of plant- and manure-derived PyOM (n = 10). The net energy value (ΔE) for PyOM was between 4.0 and 175 kJ mol-1; with manure-derived PyOM having themore » highest ΔE. Thermal-oxidation activation energy (Ea) requirements ranged from 51 to 125 kJ mol-1, with wood-derived PyOM having the highest Ea requirements. We propose a return-on-investment (ROI) parameter (ΔE/Ea) for differentiating short-to-medium term biodegradability of PyOM and deciphering if biodegradation will most likely proceed via co-metabolism (ROI < 1) or direct metabolism (ROI ≥ 1). The ROI-biodegradability relationship was sigmoidal with higher biodegradability associated with PyOM of higher ROI; indicating that microbes exhibit a higher preference for “high investment value” PyOM.« less

Optimizing contaminant desorption and bioavailability in dense slurry systems. 2. PAH bioavailability and rates of degradation.

PubMed

Kim, Han S; Weber, Walter J

2005-04-01

The effects of mechanical mixing on rates of polycyclic aromatic hydrocarbon (PAH) biodegradation in dense geosorbent slurry (67% solids content, w/w) systems were evaluated using laboratory-scale intermittently mixed batch bioreactors. A PAH-contaminated soil and a phenanthrene-sorbed mineral sorbent (alpha-Al2O3) were respectively employed as slurry solids in aerobic and anaerobic biodegradation studies. Both slurries exhibited a characteristic behavior of pseudoplastic non-Newtonian fluids, and the impeller revolution rate and its diameter had dramatic impacts on power and torque requirements in their laminar flow mixing. Rates of phenanthrene biodegradation were markedly enhanced by relatively low-level auger mixing under both aerobic and anaerobic (denitrifying) conditions. Parameters for empirical models correlating biodegradation rate coefficient (k(b)) values to the degree of mixing were similar to those for correlations between mass transfer (desorption) rate coefficient (k(r)) values for rapidly desorbing fractions of soil organic matter and degree of mixing reported in a companion study, supporting a conclusion that performance-efficient and cost-effective enhancements of PAH mass transfer (desorption) and its biodegradation processes can be achieved by the introduction of optimal levels of reactor-scale mechanical mixing.

Influence of Biodegradation on the Organic Compounds Composition of Peat.

NASA Astrophysics Data System (ADS)

Serebrennikova, Olga; Svarovskaya, Lidiya; Duchko, Maria; Strelnikova, Evgeniya; Russkikh, Irina

2016-06-01

Largest wetland systems are situated on the territory of the Tomsk region. They are characterized by the high content of organic matter (OM), which undergoes transformation as a result of physical, chemical and biological processes. The composition of peat OM is determined by the nature of initial peat-forming plants, their transformation products and bacteria. An experiment in stimulated microbial impact was carried out for estimating the influence of biodegradation on the composition of peat lipids. The composition of the functional groups in the bacterial biomass, initial peat and peat after biodegradation was determined by IR-spectroscopy using the spectrometer NICOLET 5700. The IR spectra of peat and bacteria organic matter are characterized by the presence of absorption bands in ranges: 3400-3200 cm-1, which refers to the stretching vibrations of OH-group of carboxylic acids and various types of hydrogen bonds; 1738-1671 cm-1 - characteristic stretching vibrations of the C = O group of carboxylic acids and ketones; 1262 cm-1 - stretching vibrations of C-O of carboxylic acids. Group and individual composition of organic compounds in studied samples was determined by gas chromatography-mass-spectrometry.

Effect of PAC dosage in a pilot-scale PAC-MBR treating micro-polluted surface water.

PubMed

Hu, Jingyi; Shang, Ran; Deng, Huiping; Heijman, Sebastiaan G J; Rietveld, Luuk C

2014-02-01

To address the water scarcity issue and advance the traditional drinking water treatment technique, a powdered activated carbon-amended membrane bioreactor (PAC-MBR) is proposed for micro-polluted surface water treatment. A pilot-scale study was carried out by initially dosing different amounts of PAC into the MBR. Comparative results showed that 2g/L performed the best among 0, 1, 2 and 3g/L PAC-MBR regarding organic matter and ammonia removal as well as membrane flux sustainability. 1g/L PAC-MBR exhibited a marginal improvement in pollutant removal compared to the non-PAC system. The accumulation of organic matter in the bulk mixture of 3g/L PAC-MBR led to poorer organic removal and severer membrane fouling. Molecular weight distribution of the bulk liquid in 2g/L PAC-MBR revealed the synergistic effects of PAC adsorption/biodegradation and membrane rejection on organic matter removal. Additionally, a lower amount of soluble extracellular polymer substances in the bulk can be secured in 21 days operation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Simultaneous attenuation of pharmaceuticals, organic matter, and nutrients in wastewater effluent through managed aquifer recharge: Batch and column studies.

PubMed

Im, Huncheol; Yeo, Inseol; Maeng, Sung Kyu; Park, Chul Hwi; Choi, Heechul

2016-01-01

Batch and column experiments were conducted to evaluate the removal of organic matter, nutrients, and pharmaceuticals and to identify the removal mechanisms of the target contaminants. The sands used in the experiments were obtained from the Youngsan River located in South Korea. Neutral and cationic pharmaceuticals (iopromide, estrone, and trimethoprim) were removed with efficiencies greater than 80% from different sand media during experiments, due to the effect of sorption between sand and pharmaceuticals. However, the anionic pharmaceuticals (sulfamethoxazole, ketoprofen, ibuprofen, and diclofenac) were more effectively removed by natural sand, compared to baked sand. These observations were mainly attributed to biodegradation under natural conditions of surface organic matter and ATP concentrations. The removal of organic matter and nitrogen was also found to increase under biotic conditions. Therefore, it is indicated that biodegradation plays an important role and act as major mechanisms for the removal of organic matter, nutrients, and selected pharmaceuticals during sand passage and the managed aquifer recharge, which is an effective treatment method for removing target contaminants. However, the low removal efficiencies of pharmaceuticals (e.g., carbamazepine and sulfamethoxazole) require additional processes (e.g., AOPs, NF and RO membrane), a long residence time, and long travel distance for increasing the removal efficiencies. Copyright © 2015 Elsevier Ltd. All rights reserved.

Physicochemical properties and biodegradability of organically functionalized colloidal silica particles in aqueous environment.

PubMed

Schneider, Mandy; Meder, Fabian; Haiß, Annette; Treccani, Laura; Rezwan, Kurosch; Kümmerer, Klaus

2014-03-01

Engineered sub-micron particles are being used in many technical applications, leading to an increasing introduction into the aquatic environment. Only a few studies have dealt with the biodegradability of non-functionalized organic particles. In fact the knowledge of organically surface functionalized colloids is nearly non-existent. We have investigated the biodegradability of organically surface functionalized silica (SiO2) particles bearing technically relevant groups such as amino-, carboxyl-, benzyl-, sulfonate-, chloro-, and phosphatoethyl-derivatized alkyls. Essential physicochemical properties including zeta potential, isoelectric point, morphology, surface area, porosity, surface density, and elemental composition of the particles were investigated, followed by biodegradability testing using the Closed Bottle Test (OECD 301D). None of the particles met the biodegradability threshold value of 60%. Only a slight biodegradation was revealed for SiO2-Benzyl (13.7±6.7%) and for SiO2-3-Chlorpropane (10.8±1.5%). For the other particles biodegradability was below the normal background fluctuation of 5%. The results were different of those obtained from structurally similar chemicals not being functionalized on the particle surface and from general rules of structure-biodegradation prediction of organic molecules. Therefore, our results suggest that the attachment of the organic groups heavily reduces their biodegradability, increases their residence time and possibility for adverse effects to environmental species. Copyright © 2013 Elsevier Ltd. All rights reserved.

ENVIRONMENTAL BIODEGRADABILITY OF [14C] SINGLE-WALLED CARBON NANOTUBESBY TRAMETES VERSICOLOR AND NATURAL MICROBIAL CULTURES FOUND IN NEWBEDFORD HARBOR SEDIMENT AND AERATED WASTEWATER TREATMENT PLANT SLUDGE

EPA Science Inventory

Little is known about environmental biodegradability or biotransformations of single-walled carbon nanotubes (SWNT). Because of their strong association with aquatic organic matter, detailed knowledge of the ultimate fate and persistence of SWNT requires investigation of possible...

Biochemical methane potential tests of different autoclaved and microwaved lignocellulosic organic fractions of municipal solid waste.

PubMed

Pecorini, Isabella; Baldi, Francesco; Carnevale, Ennio Antonio; Corti, Andrea

2016-10-01

The aim of this research was to enhance the anaerobic biodegradability and methane production of two synthetic Organic Fractions of Municipal Solid Waste with different lignocellulosic contents by assessing microwave and autoclave pre-treatments. Biochemical Methane Potential assays were performed for 21days. Changes in the soluble fractions of the organic matter (measured by soluble chemical oxygen demand, carbohydrates and proteins), the first order hydrolysis constant kh and the cumulated methane production at 21days were used to evaluate the efficiency of microwaving and autoclaving pretreatments on substrates solubilization and anaerobic digestion. Microwave treatment led to a methane production increase of 8.5% for both the tested organic fractions while autoclave treatment had an increase ranging from 1.0% to 4.4%. Results showed an increase of the soluble fraction after pre-treatments for both the synthetic organic fractions. Soluble chemical oxygen demand observed significant increases for pretreated substrates (up to 219.8%). In this regard, the mediocre results of methane's production led to the conclusion that autoclaving and microwaving resulted in the hydrolysis of a significant fraction of non-biodegradable organic substances recalcitrant to anaerobic digestion. Copyright © 2016 Elsevier Ltd. All rights reserved.

Dissolved oxygen saturation controls PAH biodegradation in freshwater estuary sediments.

PubMed

Boyd, T J; Montgomery, M T; Steele, J K; Pohlman, J W; Reatherford, S R; Spargo, B J; Smith, D C

2005-02-01

Polycyclic aromatic hydrocarbons (PAHs) are common contaminants in terrestrial and aquatic environments and can represent a significant constituent of the carbon pool in coastal sediments. We report here the results of an 18-month seasonal study of PAH biodegradation and heterotrophic bacterial production and their controlling biogeochemical factors from 186 sediment samples taken in a tidally influenced freshwater estuary. For each sampling event, measurements were averaged from 25-45 stations covering approximately 250 km(2). There was a clear relationship between bacterial production and ambient temperature, but none between production and bottom water dissolved oxygen (DO) % saturation or PAH concentrations. In contrast with other studies, we found no effect of temperature on the biodegradation of naphthalene, phenanthrene, or fluoranthene. PAH mineralization correlated with bottom water DO saturation above 70% (r(2) > 0.99). These results suggest that the proportional utilization of PAH carbon to natural organic carbon is as much as three orders of magnitude higher during cooler months, when water temperatures are lower and DO % saturation is higher. Infusion of cooler, well-oxygenated water to the water column overlying contaminated sediments during the summer months may stimulate PAH metabolism preferentially over non-PAH organic matter.

Biodegradation kinetics of dissolved organic matter chromatographic fractions in an intermittent river

NASA Astrophysics Data System (ADS)

Catalán, N.; Casas-Ruiz, J. P.; von Schiller, D.; Proia, L.; Obrador, B.; Zwirnmann, E.; Marcé, R.

2017-01-01

Controls on the degradation of dissolved organic matter (DOM) are complex but key to understand the role of freshwaters in the carbon cycle. Both the origin and previous degradation history have been suggested to determine DOM reactivity, but it is still a major challenge to understand the links between DOM composition and biodegradation kinetics. An appropriate context to study these links are intermittent rivers, as summer drought naturally diversifies DOM sources and sinks. Here we investigated the biodegradation kinetics of DOM in the main aquatic environments present in a temporary river. During dark incubations we traced the dynamics of bulk DOM and its main chromatographic fractions defined using LC-OCD: high molecular weight substances (HMWS), low molecular weight substances (LMWS), and humic substances and building blocks. Bulk DOM decay patterns were successfully fitted to the reactivity continuum (RC) biodegradation model. The RC parameters depicted running waters as the sites presenting a more reactive DOM, and temporary pools, enriched in leaf litter, as the ones with slowest DOM decay. The decay patterns of each DOM fraction were consistent throughout sites. LMWS and HMWS decayed in all cases and could be modeled using the RC model. Notably, the dynamics of LMWS controlled the bulk DOM kinetics. We discuss the mechanistic basis for the chromatographic fractions' kinetics during biodegradation and the implications that preconditioning and summer drought can have for DOM biodegradation in intermittent rivers.

Effects of crop rotation and management system on water-extractable organic matter concentration, structure, and bioavailability in a chernozemic agricultural soil.

PubMed

Xu, Na; Wilson, Henry F; Saiers, James E; Entz, Martin

2013-01-01

Water-extractable organic matter (WEOM) in soil affects contaminant mobility and toxicity, heterotrophic production, and nutrient cycling in terrestrial and aquatic ecosystems. This study focuses on the influences of land use history and agricultural management practices on the water extractability of organic matter and nutrients from soils. Water-extractable organic matter was extracted from soils under different crop rotations (an annual rotation of wheat-pea/bean-wheat-flax or a perennial-based rotation of wheat-alfalfa-alfalfa-flax) and management systems (organic or conventional) and examined for its concentration, composition, and biodegradability. The results show that crop rotations including perennial legumes increased the concentration of water-extractable organic carbon (WEOC) and water-extractable organic nitrogen (WEON) and the biodegradability of WEOC in soil but depleted the quantity of water-extractable organic phosphorus (WEOP) and water-extractable reactive phosphorus. The 30-d incubation experiments showed that bioavailable WEOC varied from 12.5% in annual systems to 22% for perennial systems. The value of bioavailable WEOC was found to positively correlate with WEON concentrations and to negatively correlate with C:N ratio and the specific ultraviolet absorbance of WEOM. No significant treatment effect was present with the conventional and organic management practices, which suggested that WEOM, as the relatively labile pool in soil organic matter, is more responsive to the change in crop rotation than to mineral fertilizer application. Our results indicated that agricultural landscapes with contrasting crop rotations are likely to differentially affect rates of microbial cycling of organic matter leached to soil waters. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Study of the rice straw biodegradation in mixed culture of Trichoderma viride and Aspergillus niger by GC-MS and FTIR.

PubMed

Chen, Yaoning; Huang, Jingxia; Li, Yuanping; Zeng, Guangming; Zhang, Jiachao; Huang, Aizhi; Zhang, Jie; Ma, Shuang; Tan, Xuebin; Xu, Wei; Zhou, Wei

2015-07-01

This study was conducted to investigate the biodegradation ability of the mixed culture of Trichoderma viride and Aspergillus niger through the study of the organic matter extracted from rice straw and the lignocellulose structure by using gas chromatography-mass spectrometer (GC-MS) and Fourier transform infrared spectroscopy (FTIR). The results of the GC-MS showed that the mixed culture possessed shorter alkane (heptane) at the end of the incubation and more kinds of organic matter (except the alkanes, 29 kinds of organic matter were detected) than the pure cultures. It could be deduced that the organic matter could indicate the degradation degree of the lignocellulose to some extent. Moreover, pinene was detected in the mixed culture on days 5 and 10, which might represent the antagonistic relationship between T. viride and A. niger. The analysis of FTIR spectrums which indirectly verified the GC-MS results showed that the mixed culture possessed a better degradation of rice straw compared with the pure culture. Therefore, the methods used in this research could be considered as effective ones to investigate the lignocellulose degradation mechanism in mixed culture.

Using ozone to reduce recalcitrant compounds and to enhance biodegradability of pulp and paper effluents.

PubMed

Bijan, L; Mohseni, M

2004-01-01

The effect of ozone based oxidation on removing recalcitrant organic matter (ROM) and enhancing the biodegradability of alkaline bleach plant effluent was investigated. A bubble column ozonation tower was used in the study. The experiments were carried out at different temperatures (20 degrees C and 60 degrees C) and pH (9 and 11), with a number of biological and chemical parameters being monitored including BOD5, COD, TC, pH, color, and molecular weight distribution of organics (nominal cut off of 1,000 Da). Biodegradability of the effluent was determined based on BOD5/COD of the wastewater throughout the process. For all the experiments, ozonation enhanced the biodegradability of the effluent by 30-40%, which was associated with noticeable removal of ROM including high molecular weight (HMW) and color-causing organics by about 30% and 60%, respectively. While the biodegradability of HMW fraction increased by about 50%, there was no biodegradability improvement for low molecular weight (LMW) portion, which was originally readily biodegradable (with BOD5/COD of about 0.5). Statistical analysis of variance (ANOVA) revealed neither pH nor temperature played significant role on the ozonation process at 95% confidence level.

Biodegradation of organic matter and anodic microbial communities analysis in sediment microbial fuel cells with/without Fe(III) oxide addition.

PubMed

Xu, Xun; Zhao, Qingliang; Wu, Mingsong; Ding, Jing; Zhang, Weixian

2017-02-01

To enhance the biodegradation of organic matter in sediment microbial fuel cell (SMFC), Fe(III) oxide, as an alternative electron acceptor, was added into the sediment. Results showed that the SMFC with Fe(III) oxide addition obtained higher removal efficiencies for organics than the SMFC without Fe(III) oxide addition and open circuit bioreactor, and produced a maximum power density (P max ) of 87.85mW/m 2 with a corresponding maximum voltage (V max ) of 0.664V. The alteration of UV-254 and specific ultraviolet absorbance (SUVA) also demonstrated the organic matter in sediments can be effectively removed. High-throughput sequencing of anodic microbial communities indicated that bacteria from the genus Geobacter were predominantly detected (21.23%) in the biofilm formed on the anode of SMFCs, while Pseudomonas was the most predominant genus (18.12%) in the presence of Fe(III) oxide. Additionally, compared with the open circuit bioreactor, more electrogenic bacteria attached to the biofilm of anode in SMFCs. Copyright © 2016 Elsevier Ltd. All rights reserved.

Soil type-depending effect of paddy management: composition and distribution of soil organic matter

NASA Astrophysics Data System (ADS)

Urbanski, Livia; Kölbl, Angelika; Lehndorff, Eva; Houtermans, Miriam; Schad, Peter; Zhang, Gang-Lin; Rahayu Utami, Sri; Kögel-Knabner, Ingrid

2016-04-01

Paddy soil management is assumed to promote soil organic matter accumulation and specifically lignin caused by the resistance of the aromatic lignin structure against biodegradation under anaerobic conditions during inundation of paddy fields. The present study investigates the effect of paddy soil management on soil organic matter composition compared to agricultural soils which are not used for rice production (non-paddy soils). A variety of major soil types, were chosen in Indonesia (Java), including Alisol, Andosol and Vertisol sites (humid tropical climate of Java, Indonesia) and in China Alisol sites (humid subtropical climate, Nanjing). This soils are typically used for rice cultivation and represent a large range of soil properties to be expected in Asian paddy fields. All topsoils were analysed for their soil organic matter composition by solid-state 13C nuclear magnetic resonance spectroscopy and lignin-derived phenols by CuO oxidation method. The soil organic matter composition, revealed by solid-state 13C nuclear magnetic resonance, was similar for the above named different parent soil types (non-paddy soils) and was also not affected by the specific paddy soil management. The contribution of lignin-related carbon groups to total SOM was similar in the investigated paddy and non-paddy soils. A significant proportion of the total aromatic carbon in some paddy and non-paddy soils was attributed to the application of charcoal as a common management practise. The extraction of lignin-derived phenols revealed low VSC (vanillyl, syringyl, cinnamyl) values for all investigated soils, being typical for agricultural soils. An inherent accumulation of lignin-derived phenols due to paddy management was not found. Lignin-derived phenols seem to be soil type-dependent, shown by different VSC concentrations between the parent soil types. The specific paddy management only affects the lignin-derived phenols in Andosol-derived paddy soils which are characterized by significantly higher VSC values compared to their parent soil types. However, the higher organic carbon concentrations in Andosol and Alisol (China)-derived paddy soils compared to their parent soil types, could not be explained by an enrichment of lignin-derived phenols. It seems that site specific incorporation of crop residues and properties of the parent soil types are likely more important for organic carbon contents and soil organic matter composition than the effect of paddy management itself.

Methane-producing microbial community in a coal bed of the Illinois basin.

PubMed

Strapoc, Dariusz; Picardal, Flynn W; Turich, Courtney; Schaperdoth, Irene; Macalady, Jennifer L; Lipp, Julius S; Lin, Yu-Shih; Ertefai, Tobias F; Schubotz, Florence; Hinrichs, Kai-Uwe; Mastalerz, Maria; Schimmelmann, Arndt

2008-04-01

A series of molecular and geochemical studies were performed to study microbial, coal bed methane formation in the eastern Illinois Basin. Results suggest that organic matter is biodegraded to simple molecules, such as H(2) and CO(2), which fuel methanogenesis and the generation of large coal bed methane reserves. Small-subunit rRNA analysis of both the in situ microbial community and highly purified, methanogenic enrichments indicated that Methanocorpusculum is the dominant genus. Additionally, we characterized this methanogenic microorganism using scanning electron microscopy and distribution of intact polar cell membrane lipids. Phylogenetic studies of coal water samples helped us develop a model of methanogenic biodegradation of macromolecular coal and coal-derived oil by a complex microbial community. Based on enrichments, phylogenetic analyses, and calculated free energies at in situ subsurface conditions for relevant metabolisms (H(2)-utilizing methanogenesis, acetoclastic methanogenesis, and homoacetogenesis), H(2)-utilizing methanogenesis appears to be the dominant terminal process of biodegradation of coal organic matter at this location.

Sorptive fractionation of organic matter and formation of organo-hydroxy-aluminum complexes during litter biodegradation in the presence of gibbsite

Treesearch

K. Heckman; A.S. Grandy; X. Gao; M. Keiluweit; K. Wickings; K. Carpenter; J. Chorover; C. Rasmussen

2013-01-01

Solid and aqueous phase Al species are recognized to affect organic matter (OM) stabilization in forest soils. However, little is known about the dynamics of formation, composition and dissolution of organo-Al hydroxide complexes in microbially-active soil systems, where plant litter is subject to microbial decomposition in close proximity to mineral weathering...

Characterization and source identification of organic matter in view of land uses and heavy rainfall in the Lake Shihwa, Korea.

PubMed

Lee, Yeonjung; Hur, Jin; Shin, Kyung-Hoon

2014-07-15

The characteristics and sources of organic matter in water of the Lake Shihwa, which receives inputs from rural, urban, and industrial areas, were evaluated by examining the biodegradable organic carbon concentration, fluorescence spectra, and carbon and nitrogen isotope ratios, especially during rainy season and dry season. The organic matter transported from rural areas was of refractory nature, while that of industrial origin decomposed rapidly. As compared to the dry season, the organic matter in the rainy season was characterized by a reduced labile fraction. During the dry season, the autochthonous organic matter dominated in the lake, however, the contributions of allochthonous organic sources by industrial and rural areas significantly increased at rainy season. This investigation revealed that the transport of organic matter of anthropogenic origin to the Lake Shihwa was mainly influenced by heavy rainfall. Moreover, each anthropogenic source could differently influence the occurrence of organic matter in water of the Lake Shihwa. Copyright © 2014 Elsevier Ltd. All rights reserved.

Comparison between the evaluation of bacterial regrowth capability in a turbidimeter and biodegradable dissolved organic carbon bioreactor measurements in water.

PubMed

Kott, Y; Ribas, F; Frías, J; Lucena, F

1997-09-01

In recent years, two different approaches to the study of biodegradable organic matter in distribution systems have been followed. The assimilable organic carbon (AOC) indicates the portion of the dissolved organic matter used by bacteria and converted to biomass, which is directly measured as total bacteria, active bacteria or colony-forming units and indirectly as ATP or increase in turbidity. In contrast, the biodegradable dissolved organic carbon (BDOC) is the portion of the dissolved organic carbon that can be mineralized by heterotrophic microorganisms, and it is measured as the difference between the inflow and the outflow of a bioreactor. In this study, at different steps in a water treatment plant, the bacterial regrowth capability was determined by the AOC method that measures the maximum growth rate by using a computerized Monitek turbidimeter. The BDOC was determined using a plug flow bioreactor. Measurements of colony-forming units and total organic carbon (TOC) evolution in a turbidimeter and of colony-forming units at the inflow/outflow of the bioreactor were also performed, calculating at all sampling points the coefficient yield (Y = cfu/delta TOC) in both systems. The correlations between the results from the bioreactor and turbidimeter have been calculated; a high correlation level was observed between BDOC values and all the other parameters, except for Y calculated from bacterial suspension measured in the turbidimeter.

Effect of biostimulants on 2,4,6-trinitrotoluene (TNT) degradation and bacterial community composition in contaminated aquifer sediment enrichments.

PubMed

Fahrenfeld, Nicole; Zoeckler, Jeffrey; Widdowson, Mark A; Pruden, Amy

2013-04-01

2,4,6-Trinitrotoluene (TNT) is a toxic and persistent explosive compound occurring as a contaminant at numerous sites worldwide. Knowledge of the microbial dynamics driving TNT biodegradation is limited, particularly in native aquifer sediments where it poses a threat to water resources. The purpose of this study was to quantify the effect of organic amendments on anaerobic TNT biodegradation rate and pathway in an enrichment culture obtained from historically contaminated aquifer sediment and to compare the bacterial community dynamics. TNT readily biodegraded in all microcosms, with the highest biodegradation rate obtained under the lactate amended condition followed by ethanol amended and naturally occurring organic matter (extracted from site sediment) amended conditions. Although a reductive pathway of TNT degradation was observed across all conditions, denaturing gradient gel electrophoresis (DGGE) analysis revealed distinct bacterial community compositions. In all microcosms, Gram-negative γ- or β-Proteobacteria and Gram-positive Negativicutes or Clostridia were observed. A Pseudomonas sp. in particular was observed to be stimulated under all conditions. According to non-metric multidimensional scaling analysis of DGGE profiles, the microcosm communities were most similar to heavily TNT-contaminated field site sediment, relative to moderately and uncontaminated sediments, suggesting that TNT contamination itself is a major driver of microbial community structure. Overall these results provide a new line of evidence of the key bacteria driving TNT degradation in aquifer sediments and their dynamics in response to organic carbon amendment, supporting this approach as a promising technology for stimulating in situ TNT bioremediation in the subsurface.

Development of a hybrid ozonation biofilm-membrane filatration process for the production of drinking water.

PubMed

Leiknes, T; Lazarova, M; Odegaard, H

2005-01-01

Drinking water sources in Norway are characterized by high concentrations of natural organic matter (NOM), low alkalinity and low turbidity. The removal of NOM is therefore a general requirement in producing potable water. Drinking water treatment plants are commonly designed with coagulation direct filtration or NF spiral wound membrane processes. This study has investigated the feasibility and potential of a hybrid process combining ozonation and biofiltration with a rotating disk membrane for treating drinking water with high NOM concentrations. Ozonation will oxidize the NOM content removing colour and form biodegradable organic compounds, which can be removed in biological filters. A constructed water was used in this study which is representative of ozonated NOM-containing water. A rotating membrane disk bioreactor downstream the ozonation process was used to carry out both the biodegradation as well as biomass separation in the same reactor. Maintenance of biodegradation of the organic matter while controlling biofouling of the membrane and acceptable water production rates was the focus in the study. Three operating modes were investigated. Removal of the biodegradable organics was consistent throughout the study indicating that sufficient biomass was maintained in the reactor for all operating conditions tested. Biofouling control was not achieved through shear-induced cleaning by periodically rotating the membrane disks at high speed. By adding a small amount of sponges in the membrane chamber the biofouling could be controlled by mechanical cleaning of the membrane surface during disk rotation. The overall results indicate that the system can favorably be used in an ozonation/biofiltration process by carrying out both biodegradation as well as biomass separation in the same reactor.

Biodegradation of acetanilide herbicides acetochlor and butachlor in soil.

PubMed

Ye, Chang-ming; Wang, Xing-jun; Zheng, He-hui

2002-10-01

The biodegradation of two acetanilide herbicides, acetochlor and butachlor in soil after other environmental organic matter addition were measured during 35 days laboratory incubations. The herbicides were applied to soil alone, soil-SDBS (sodium dodecylbenzene sulfonate) mixtures and soil-HA (humic acid) mixtures. Herbicide biodegradation kinetics were compared in the different treatment. Biodegradation products of herbicides in soil alone samples were identified by GC/MS at the end of incubation. Addition of SDBS and HA to soil decreased acetochlor biodegradation, but increased butachlor biodegradation. The biodegradation half-life of acetochlor and butachlor in soil alone, soil-SDBS mixtures and soil-HA mixtures were 4.6 d, 6.1 d and 5.4 d and 5.3 d, 4.9 d and 5.3 d respectively. The biodegradation products were hydroxyacetochlor and 2-methyl-6-ethylaniline for acetochlor, and hydroxybutachlor and 2,6-diethylaniline for butachlor.

Escherichia coli Behavior in the Presence of Organic Matter Released by Algae Exposed to Water Treatment Chemicals

PubMed Central

Bouteleux, C.; Saby, S.; Tozza, D.; Cavard, J.; Lahoussine, V.; Hartemann, P.; Mathieu, L.

2005-01-01

When exposed to oxidation, algae release dissolved organic matter with significant carbohydrate (52%) and biodegradable (55 to 74%) fractions. This study examined whether algal organic matter (AOM) added in drinking water can compromise water biological stability by supporting bacterial survival. Escherichia coli (1.3 × 105 cells ml−1) was inoculated in sterile dechlorinated tap water supplemented with various qualities of organic substrate, such as the organic matter coming from chlorinated algae, ozonated algae, and acetate (model molecule) to add 0.2 ± 0.1 mg of biodegradable dissolved organic carbon (BDOC) liter−1. Despite equivalent levels of BDOC, E. coli behavior depended on the source of the added organic matter. The addition of AOM from chlorinated algae led to an E. coli growth equivalent to that in nonsupplemented tap water; the addition of AOM from ozonated algae allowed a 4- to 12-fold increase in E. coli proliferation compared to nonsupplemented tap water. Under our experimental conditions, 0.1 mg of algal BDOC was sufficient to support E. coli growth, whereas the 0.7 mg of BDOC liter−1 initially present in drinking water and an additional 0.2 mg of BDOC acetate liter−1 were not sufficient. Better maintenance of E. coli cultivability was also observed when AOM was added; cultivability was even increased after addition of AOM from ozonated algae. AOM, likely to be present in treatment plants during algal blooms, and thus potentially in the treated water may compromise water biological stability. PMID:15691924

Reply to 'Comment on kinetic modeling of microbially-driven redox chemistry of subsurface environments: coupling transport, microbial metabolism and geochemistry' by J. Griffioen

NASA Astrophysics Data System (ADS)

Hunter, K. S.; Van Cappellen, P.

2000-01-01

Our paper, 'Kinetic modeling of microbially-driven redox chemistry of subsurface environments: coupling transport, microbial metabolism and geochemistry' (Hunter et al., 1998), presents a theoretical exploration of biogeochemical reaction networks and their importance to the biogeochemistry of groundwater systems. As with any other model, the kinetic reaction-transport model developed in our paper includes only a subset of all physically, biologically and chemically relevant processes in subsurface environments. It considers aquifer systems where the primary energy source driving microbial activity is the degradation of organic matter. In addition to the primary biodegradation pathways of organic matter (i.e. respiration and fermentation), the redox chemistry of groundwaters is also affected by reactions not directly involving organic matter oxidation. We refer to the latter as secondary reactions. By including secondary redox reactions which consume reduced reaction products (e.g., Mn2+, FeS, H2S), and in the process compete with microbial heterotrophic populations for available oxidants (i.e. O2, NO3-, Mn(IV), Fe(III), SO42-), we predict spatio-temporal distributions of microbial activity which differ significantly from those of models which consider only the biodegradation reactions. That is, the secondary reactions have a significant impact on the distributions of the rates of heterotrophic and chemolithotrophic metabolic pathways. We further show that secondary redox reactions, as well as non-redox reactions, significantly influence the acid-base chemistry of groundwaters. The distributions of dissolved inorganic redox species along flowpaths, however, are similar in simulations with and without secondary reactions (see Figs. 3(b) and 7(b) in Hunter et al., 1998), indicating that very different biogeochemical reaction dynamics may lead to essentially the same chemical redox zonation of a groundwater system.

Combining asymmetrical flow field-flow fractionation with on- and off-line fluorescence detection to examine biodegradation of riverine dissolved and particulate organic matter.

PubMed

Lee, Sang Tak; Yang, Boram; Kim, Jin-Yong; Park, Ji-Hyung; Moon, Myeong Hee

2015-08-28

This study demonstrated that asymmetrical flow field-flow fractionation (AF4) coupled with on-line UV and fluorescence detection (FLD) and off-line excitation-emission matrix (EEM) fluorescence spectroscopy can be employed to analyze the influence of microbial metabolic activity on the consumption and production of freshwater organic matter. With the AF4 system, organic matter is on-line enriched during a focusing/relaxation period, which is an essential process prior to separation. Size-fractionated chromophoric and fluorophoric organic materials were simultaneously monitored during the 30-min AF4 separation process. Two fractions of different sizes (dissolved organic matter (DOM) and particulate organic matter (POM)) of freshwater samples from three locations (up-, mid-, and downstream) along the Han River basin of Korea were incubated with the same inoculum for 14 days to analyze fraction-specific alterations in optical properties using AF4-UV-FLD. A comparison of AF4 fractograms obtained from pre- and post-incubation samples revealed that POM-derived DOM were more susceptible to microbial metabolic activity than was DOM. Preferential microbial consumption of protein-like DOM components concurred with enhanced peaks of chromophoric and humic-like fluorescent components, presumably formed as by-products of microbial processing. AF4-UV-FLD combined with off-line identification of microbially processed components using EEM fluorescence spectroscopy provides a powerful tool to study the relationship between microbial activity and composition as well as biodegradability of DOM and POM-derived DOM from different origins, especially for the analysis of chromophoric and fluorophoric organic matter that are consumed and produced by microbial metabolic activity. The proposed AF4 system can be applied to organic matter in freshwater samples having low concentration range (0.3-2.5ppm of total organic carbon) without a pre-concentration procedure. Copyright © 2015 Elsevier B.V. All rights reserved.

Methylparaben removal using heterogeneous photocatalysis: effect of operational parameters and mineralization/biodegradability studies.

PubMed

Zúñiga-Benítez, Henry; Peñuela, Gustavo A

2017-03-01

Methylparaben (MePB) is an organic compound employed mainly in the manufacture of different personal care products. However, it has been recently listed as a potential endocrine disrupter chemical. Therefore, the main objective of this work was to evaluate the degradation of MePB in aqueous solutions using heterogeneous photocatalysis with TiO 2 and hydrogen peroxide. In this way, effects of pH and the initial concentrations of catalyst, H 2 O 2 , and pollutant on treatment were analyzed. A face centered, central composite design was used for determination of the influence of each parameter in the process and the conditions under which the pollutant suffers the highest rates of degradation were selected. In general, results indicate that combination TiO 2 /H 2 O 2 /light irradiation leads to ∼90 % of substrate removal after 30 min of reaction and that hydroxyl free radicals are the main specie responsible for organic matter elimination. Finally, in terms of mineralization and biodegradability, experimental results indicated that part of the organic matter was transformed into CO 2 and water and the photo-treatment promoted an increase in samples biodegradability.

Sorption of carbamazepine, 17α-ethinylestradiol, iopromide and trimethoprim to biomass involves interactions with exocellular polymeric substances.

PubMed

Khunjar, Wendell O; Love, Nancy G

2011-02-01

The sorption of carbamazepine (CBZ), iopromide (IOP), trimethoprim (TMP) and 17α-ethinylestradiol (EE2) was evaluated using four biomass types (pure ammonia oxidizing bacterial culture, two heterotrophic enrichment cultures with varying levels of oxygenase activity, and a full-scale nitrifying activated sludge (NAS) culture). CBZ and IOP did not sorb to the four biomass types. EE2 did not sorb to the pure culture but sorbed significantly to the heterotrophic cultures and NAS. TMP sorbed to the heterotrophic cultures and NAS, and was not evaluated for the pure culture. Three floc characteristics (hydrophobicity, median particle size, organic matter content) correlated moderately well with the EE2 organic matter sorption coefficient (KOM,EE2). Zeta potential did not correlate well with KOM,EE2 but did with KOM,TMP, indicating that TMP sorption is more influenced by electrostatic factors than EE2. Once divalent cation-linked exocellular polymeric substances (EPS) were removed from flocs, EE2 and TMP sorption to the non-EPS (cellular) fraction decreased by approximately 50%. The correlation between KOM,EE2 for the non-EPS cellular fraction deteriorated while the correlation between KOM,TMP improved. EE2 seemed to sorb more strongly to EPS protein whereas TMP sorbed equally to polysaccharide and protein EPS. Attempts to develop predictive models were not successful. Pharmaceuticals that sorbed to biomass samples underwent biodegradation whereas those that did not sorb were not biodegraded, suggesting a relationship between sorption and pharmaceutical biotransformation. Copyright © 2010 Elsevier Ltd. All rights reserved.

Effect of photodegradation and biodegradation on the concentration and composition of dissolved organic matter in diverse waterbodies

NASA Astrophysics Data System (ADS)

Manalilkada Sasidharan, S.; Dash, P.; Singh, S.; Lu, Y.

2017-12-01

The objective of this research was to quantify the effects of photodegradation and biodegradation on the dissolved organic matter (DOM) concentration and composition in five distinct waterbodies with diverse types of watershed land use and land cover in the southeastern United States. The water bodies included an agricultural pond, a lake in a predominantly forested watershed, a man-made reservoir, an estuary, and a bay. Two sets of samples were prepared from these water bodies by dispensing filtered water samples to unfiltered samples in 10:1 ratio. The first set was kept in the sunlight during the day (12 hours), and colored dissolved organic matter (CDOM) absorption and fluorescence were measured periodically over a 30-day period for examining the effects of combined photo- and biodegradation. The second set of samples was kept in the dark for examining the effects of biodegradation alone, and CDOM absorption and fluorescence were measured at the same time as the sunlight-exposed samples. Subsequently, spectrometric results in tandem with multivariate statistical analysis were used to interpret the lability vs. composition of DOM. Parallel factor analysis (PARAFAC) revealed the presence of four DOM components (C1-C4). C1 and C4 were microbial tryptophan-like, labile lighter components, while C2 and C3 were terrestrial humic like or fulvic acid type, larger aromatic refractory components. The principal component analysis (PCA) also revealed two distinct groups of DOM - C1 and C4 vs. C2 and C3. The negative PC1 loadings of C2, C3, HIX, a254 and SUVA indicated humic-like or fulvic-like structurally complex refractory aromatic DOM originated from higher plants in forested areas. C1, C4, SR, FI and BI had positive PC1 loadings, which indicated structurally simpler labile DOM were derived from agricultural areas or microbial activity. There was a decrease in dissolved organic carbon (DOC) due to combined photo- and biodegradation, and transformation of components C2, C3 into components C1, C4 was at a much faster rate than only biodegradation. This observation suggests that the presence of sunlight facilitated the degradation of larger, recalcitrant, terrestrial humic-like compounds into smaller, labile microbial components.

Distribution and biodegradability of water soluble organic carbon and nitrogen in subarctic Alaskan soils under three different land uses

USDA-ARS?s Scientific Manuscript database

Water-extractable organic matter (WEOM) contains labile organic carbon (C) and nitrogen (N) and is sensitive to soil management. However, knowledge about quantitative changes of water soluble organic C (WSOC) and N (WSON) impacted by land use conversion is still limited. In this chapter, the level a...

Determination of the origin of dissolved inorganic carbon in groundwater around a reclaimed landfill in Otwock using stable carbon isotopes.

PubMed

Porowska, Dorota

2015-05-01

Chemical and isotopic analyses of groundwater from piezometers located around a reclaimed landfill in Otwock (Poland) were performed in order to trace the origin of dissolved inorganic carbon (DIC) in the groundwater. Due to differences in the isotopic composition of carbon from different sources, an analysis of stable carbon isotopes in the groundwater, together with the Keeling plot approach and a two-component mixing model allow us to evaluate the relative contributions of carbon from these sources in the groundwater. In the natural (background) groundwater, DIC concentrations and the isotopic composition of DIC (δ(13)CDIC) comes from two sources: decomposition of organic matter and carbonate dissolution within the aquifer sediments, whereas in the leachate-contaminated groundwater, DIC concentrations and δ(13)CDIC values depend on the degradation of organic matter within the aquifer sediments and biodegradation of organic matter stored in the landfill. From the mixing model, about 4-54% of the DIC pool is derived from organic matter degradation and 96-46% from carbonate dissolution in natural conditions. In the leachate-contaminated groundwater, about 20-53% of the DIC is derived from organic matter degradation of natural origin and 80-47% from biodegradation of organic matter stored in the landfill. Partial pressure of CO2 (P CO2) was generally above the atmospheric, hence atmospheric CO2 as a source of carbon in DIC pool was negligible in the aquifer. P CO2 values in the aquifer in Otwock were always one to two orders of magnitude above the atmospheric P CO2, and thus CO2 escaped directly into the vadose zone. Copyright © 2015 Elsevier Ltd. All rights reserved.

Modelling for environmental assessment of municipal solid waste landfills (part II: biodegradation).

PubMed

Garcia de Cortázar, Amaya Lobo; Lantarón, Javier Herrero; Fernández, Oscar Montero; Monzón, Iñaki Tejero; Lamia, Maria Fantelli

2002-12-01

The biodegradation module of a simulation program for municipal solid waste landfills (MODUELO) was developed. The biodegradation module carries out the balance of organic material starting with the results of the hydrologic simulation and the waste composition. It simulates the biologic reactions of hydrolysis of solids and the gasification of the dissolved biodegradable material. The results of this module are: organic matter (COD, BOD and elemental components such as carbon, hydrogen, nitrogen, oxygen, sulfur and ash), ammonium nitrogen generated with the gas and transported by the leachates and the potential rates of methane and carbon dioxide generation. The model was calibrated by using the general tendency curves of the pollutants recorded in municipal solid waste landfills, fitting the first part of them to available landfill data. Although the results show some agreement, further work is being done to make MODUELO a useful tool for real landfill simulation.

Geochemistry of Dissolved Organic Matter in a Spatially Highly Resolved Groundwater Petroleum Hydrocarbon Plume Cross-Section.

PubMed

Dvorski, Sabine E-M; Gonsior, Michael; Hertkorn, Norbert; Uhl, Jenny; Müller, Hubert; Griebler, Christian; Schmitt-Kopplin, Philippe

2016-06-07

At numerous groundwater sites worldwide, natural dissolved organic matter (DOM) is quantitatively complemented with petroleum hydrocarbons. To date, research has been focused almost exclusively on the contaminants, but detailed insights of the interaction of contaminant biodegradation, dominant redox processes, and interactions with natural DOM are missing. This study linked on-site high resolution spatial sampling of groundwater with high resolution molecular characterization of DOM and its relation to groundwater geochemistry across a petroleum hydrocarbon plume cross-section. Electrospray- and atmospheric pressure photoionization (ESI, APPI) ultrahigh resolution mass spectrometry (FT-ICR-MS) revealed a strong interaction between DOM and reactive sulfur species linked to microbial sulfate reduction, i.e., the key redox process involved in contaminant biodegradation. Excitation emission matrix (EEM) fluorescence spectroscopy in combination with Parallel Factor Analysis (PARAFAC) modeling attributed DOM samples to specific contamination traits. Nuclear magnetic resonance (NMR) spectroscopy evaluated the aromatic compounds and their degradation products in samples influenced by the petroleum contamination and its biodegradation. Our orthogonal high resolution analytical approach enabled a comprehensive molecular level understanding of the DOM with respect to in situ petroleum hydrocarbon biodegradation and microbial sulfate reduction. The role of natural DOM as potential cosubstrate and detoxification reactant may improve future bioremediation strategies.

Methane-producing microbial community in a coal bed of the Illinois Basin

USGS Publications Warehouse

Strapoc, D.; Picardal, F.W.; Turich, C.; Schaperdoth, I.; Macalady, J.L.; Lipp, J.S.; Lin, Y.-S.; Ertefai, T.F.; Schubotz, F.; Hinrichs, K.-U.; Mastalerz, Maria; Schimmelmann, A.

2008-01-01

A series of molecular and geochemical studies were performed to study microbial, coal bed methane formation in the eastern Illinois Basin. Results suggest that organic matter is biodegraded to simple molecules, such as H 2 and CO2, which fuel methanogenesis and the generation of large coal bed methane reserves. Small-subunit rRNA analysis of both the in situ microbial community and highly purified, methanogenic enrichments indicated that Methanocorpusculum is the dominant genus. Additionally, we characterized this methanogenic microorganism using scanning electron microscopy and distribution of intact polar cell membrane lipids. Phylogenetic studies of coal water samples helped us develop a model of methanogenic biodegradation of macromolecular coal and coal-derived oil by a complex microbial community. Based on enrichments, phylogenetic analyses, and calculated free energies at in situ subsurface conditions for relevant metabolisms (H2-utilizing methanogenesis, acetoclastic methanogenesis, and homoacetogenesis), H 2-utilizing methanogenesis appears to be the dominant terminal process of biodegradation of coal organic matter at this location. Copyright ?? 2008, American Society for Microbiology. All Rights Reserved.

Biofuel from "humified" biomass

NASA Astrophysics Data System (ADS)

Kpogbemabou, D.; Lemée, L.; Amblès, A.

2009-04-01

In France, 26% of the emissions of greenhouse effect gas originate from transportation which depends for 87% on fossil fuels. Nevertheless biofuels can contribute to the fight against climate change while reducing energetic dependence. Indeed biomass potentially represents in France 30 Mtoe a year that is to say 15% national consumption. But 80% of these resources are made of lignocellulosic materials which are hardly exploitable. First-generation biofuels are made from sugar, starch, vegetable oil, or animal fats. Due to their competition with human food chain, first-generation biofuels could lead to food shortages and price rises. At the contrary second-generation biofuel production can use a variety of non food crops while using the lignocellulosic part of biomass [1]. Gasification, fermentation and direct pyrolysis are the most used processes. However weak yields and high hydrogen need are limiting factors. In France, the National Program for Research on Biofuels (PNRB) aims to increase mobilizable biomass resource and to develop lignocellulosic biomass conversion. In this context, the LIGNOCARB project studies the liquefaction of biodegraded biomass in order to lower hydrogen consumption. Our aim was to develop and optimize the biodegradation of the biomass. Once the reactor was achieved, the influence of different parameters (starting material, aeration, moisture content) on the biotransformation process was studied. The monitored parameters were temperature, pH and carbon /nitrogen ratio. Chemical (IHSS protocol) and biochemical (van Soest) fractionations were used to follow the maturity ("humic acid"/"fulvic acid" ratio) and the biological stability (soluble, hemicelluloses, celluloses, lignin) of the organic matter (OM). In example, the increase in lignin can be related to the stabilization since the OM becomes refractory to biodegradation whereas the increase in the AH/AF ratio traduces "humification". However, contrarily to the composting process, we do not look forward to obtain a mature OM for which the carbon loss would be too important. The global analysis of the biomass OM during biodegradation using infrared spectroscopy (DRIFTS) confirms "humification". Indeed the relative intensity of bands associated to aromatics increase relatively to those associated to aliphatics[2] [3]. The molecular study of lipids and humic fractions was realised using mass spectrometry (GC/MS), pyrolysis (Py-GC/MS) and thermodesorption (Headspace-GC/MS). The decrease in lipids indicates a high biodegradation. Amongst volatile organic compounds (COVs), the isoprenoid C18 ketone which is probably produced from biodegradation of phytol is observed in all our samples. The organic matter obtained after biodegradation is stable (resistant to biodegradation) and humified but still rich in carbon. The characterisation of bacterial biomarkers will help us to specify and thus to optimize biotransformation mechanisms. [1] A. Dermirbas and Al, Progress in energy and combustion science, 33 (2007), 1 - 18. [2] P. Castaldi and Al, Waste Management, 25 (2005), 213 - 217. [3] Mr. Crube and Al, Geoderma, 130 2006, 1573 - 1586.

Electrochemically modified dissolved organic matter accelerates the combining photodegradation and biodegradation of 17α-ethinylestradiol in natural aquatic environment.

PubMed

He, Huan; Huang, Bin; Fu, Gen; Xiong, Dan; Xu, Zhixiang; Wu, Xinhao; Pan, Xuejun

2018-06-15

The photochemical conversion and microbial transformation of pollutants mediated by dissolved organic matter (DOM), including 17α-ethinylestradiol (EE2), are often accompanied in natural water. However, there are few studies to explore the connection and mechanism between the two processes. This research aims to investigate the mechanism of DOM after electrochemically modification mediated EE2 combining photodegradation and biodegradation in the environment and it want to explain the natural phenomena of DOM after electrochemical advanced treatment entering the water environment mediated EE2 natural degradation. The results showed that combining photodegradation with biodegradation rates of EE2 mediated by DOM and electrochemically modified DOM (E-DOM) were promoted obviously. The efficiency of EE2 biodegradation was shown to be strongly correlated with electron accepting capacity (EAC) of DOM. Electrochemical modification can increase the EAC of DOM leading to EE2 biodegradation accelerated, and it also can form more triplet-state DOM moieties to promote the EE2 photodegradation in irradiation conditions, due to the increasing of quinone-type structures in DOM. Moreover, cell polymeric secretion (CPS) secreted from the microorganism could be stimulated to an excited state by irradiation, and that also accelerated EE2 degradation. Photolysis combined with biochemical degradation yielded less toxic degradation products. This study shows that the emission of DOM in wastewater after electrochemical treatment could accelerate estrogen degradation and play a positive role on the pollutant transformation in the environment. Copyright © 2018 Elsevier Ltd. All rights reserved.

Linking measurements of biodegradability, thermal stability and chemical composition to evaluate the effects of management on soil organic matter

NASA Astrophysics Data System (ADS)

Gregorich, Ed; Gillespie, Adam; Beare, Mike; Curtin, Denis; Sanei, Hamed; Yanni, Sandra

2015-04-01

The stability of soil organic matter (SOM) as it relates to resistance to microbial degradation has important implications for nutrient cycling, emission of greenhouse gases, and C sequestration. Hence, there is interest in developing new ways to accurately quantify and characterise the labile and stable forms of soil organic C. Our objectives in this study were to evaluate and describe relationships among the biodegradability, thermal stability and chemistry of SOM in soil under widely contrasting management regimes. Samples from the same soil under permanent pasture, an arable cropping rotation, and chemical fallow were fractionated (sand: 2000-50 μm; silt: 50-5 μm, and clay: < 5 μm). Biodegradability of the SOM in size fractions and whole soils was assessed in a laboratory mineralization study. The chemical composition of SOM was characterized by X-ray absorption near-edge structure (XANES) spectroscopy at the K-edge and its thermal stability was determined by analytical pyrolysis using a Rock-Eval pyrolyser. The mineralization bioassay showed that whole soils and soil fractions under fallow were less susceptible to biodegradation than other managements and that sand-associated organic matter was significantly more susceptible than that in the silt or clay fractions. Analysis by XANES showed accumulation of carboxylates and strong depletion of amides (protein) and aromatics in the fallow whole soil. Moreover, protein depletion was most significant in the sand fraction of the fallow soil. Sand fractions in fallow and cropped soils were, however, enriched in plant-derived phenols, aromatics and carboxylates compared to the sand fraction of pasture soils. In contrast, ketones, which have been identified as products of microbially-processed organic matter, were slightly enriched in the silt fraction of the pasture soil. These data suggest reduced inputs and cropping restrict the decomposition of plant residues and, without supplemental N additions, protein-N in native SOM is significantly mineralized in fallow systems to meet microbial C mineralization demands. Analytical pyrolysis showed distinct differences in the thermal stability of SOM among the size fractions and management treatments; it also showed that the loss of SOM generally involved dehydrogenation. The temperature at which half of the C was pyrolyzed showed strong correlation with mineralizable C and thus provides solid evidence for a link between the biological and thermal stability of SOM.

BIOB: a mathematical model for the biodegradation of low solubility hydrocarbons.

PubMed

Geng, Xiaolong; Boufadel, Michel C; Personna, Yves R; Lee, Ken; Tsao, David; Demicco, Erik D

2014-06-15

Modeling oil biodegradation is an important step in predicting the long term fate of oil on beaches. Unfortunately, existing models do not account mechanistically for environmental factors, such as pore water nutrient concentration, affecting oil biodegradation, rather in an empirical way. We present herein a numerical model, BIOB, to simulate the biodegradation of insoluble attached hydrocarbon. The model was used to simulate an experimental oil spill on a sand beach. The biodegradation kinetic parameters were estimated by fitting the model to the experimental data of alkanes and aromatics. It was found that parameter values are comparable to their counterparts for the biodegradation of dissolved organic matter. The biodegradation of aromatics was highly affected by the decay of aromatic biomass, probably due to its low growth rate. Numerical simulations revealed that the biodegradation rate increases by 3-4 folds when the nutrient concentration is increased from 0.2 to 2.0 mg N/L. Published by Elsevier Ltd.

Photodegradation of major soil microbial biomolecules is comparable to biodegradation: Insights from infrared and diffusion editing NMR spectroscopies

NASA Astrophysics Data System (ADS)

Spence, Adrian; Kelleher, Brian P.

2016-03-01

As a primary decomposition process in terrestrial biosystems, biodegradation has been extensively studied with regard to its impact on soil organic matter transformation. However, the biotransformation of soil microbial biomass (a primary source of soil organic carbon) remains poorly understood, and even less is known about the fate of microbial-derived carbon under photodegradation. Here, we combine infrared and diffusion editing NMR spectroscopies to provide molecular-level information on the photodegradation of major biochemical components in soil microbial biomass and leachates over time. Results indicate a considerable enrichment in aliphatic components, presumably polymethylenic-C [(C-H2)n] and the simultaneous loss of carbohydrate and protein structures in the biomass. An immediate conclusion is that photodegradation increased the conversion of macromolecular carbohydrates and proteins to smaller components. However, further analysis reveals that macromolecular carbohydrates and proteins may be more resistant to photodegradation than initially thought and are found in the leachates. Although attenuated, there is also evidence to suggest that some aliphatic structures persist in the leachates. Overall, the photodegradation pathway reported here is remarkably similar to that of biodegradation, suggesting that under rapidly expanding anthropogenic land disturbances, photodegradation could be an important driver of the transformation of microbial-derived organic matter in terrestrial biosystems.

Impacts of discarded plastic bags on marine assemblages and ecosystem functioning.

PubMed

Green, Dannielle Senga; Boots, Bas; Blockley, David James; Rocha, Carlos; Thompson, Richard

2015-05-05

The accumulation of plastic debris is a global environmental problem due to its durability, persistence, and abundance. Although effects of plastic debris on individual marine organisms, particularly mammals and birds, have been extensively documented (e.g., entanglement and choking), very little is known about effects on assemblages and consequences for ecosystem functioning. In Europe, around 40% of the plastic items produced are utilized as single-use packaging, which rapidly accumulate in waste management facilities and as litter in the environment. A range of biodegradable plastics have been developed with the aspiration of reducing the persistence of litter; however, their impacts on marine assemblages or ecosystem functioning have never been evaluated. A field experiment was conducted to assess the impact of conventional and biodegradable plastic carrier bags as litter on benthic macro- and meio-faunal assemblages and biogeochemical processes (primary productivity, redox condition, organic matter content, and pore-water nutrients) on an intertidal shore near Dublin, Ireland. After 9 weeks, the presence of either type of bag created anoxic conditions within the sediment along with reduced primary productivity and organic matter and significantly lower abundances of infaunal invertebrates. This indicates that both conventional and biodegradable bags can rapidly alter marine assemblages and the ecosystem services they provide.

Co-treatment of landfill leachate and domestic wastewater using a submerged aerobic biofilter.

PubMed

Ferraz, F M; Povinelli, J; Pozzi, E; Vieira, E M; Trofino, J C

2014-08-01

This study used a pilot-scale submerged aerobic biofilter (SAB) to evaluate the co-treatment of domestic wastewater and landfill leachate that was pre-treated by air stripping. The leachate tested volumetric ratios were 0, 2, and 5%. At a hydraulic retention time of 24 h, the SAB was best operated with a volumetric ratio of 2% and removed 98% of the biochemical oxygen demand (BOD), 80% of the chemical oxygen demand (COD) and dissolved organic carbon (DOC), and 90% of the total suspended solids (TSS). A proposed method, which we called the "equivalent in humic acid" (Eq.HA) approach, indicated that the hardly biodegradable organic matter in leachate was removed by partial degradation (71% of DOC Eq.HA removal). Adding leachate at a volumetric ratio of 5%, the concentration of the hardly biodegradable organic matter was decreased primarily as a result of dilution rather than biodegradation, which was confirmed by Fourier transform infrared (FTIR) spectroscopy. The total ammoniacal nitrogen (TAN) was mostly removed (90%) by nitrification, and the SAB performances at the volumetric ratios of 0 and 2% were equal. For the three tested volumetric ratios of leachate (0, 2, and 5%), the concentrations of heavy metals in the treated samples were below the local limits. Copyright © 2014 Elsevier Ltd. All rights reserved.

Biodegradation of vapor-phase toluene in unsaturated porous media: Column experiments.

PubMed

Khan, Ali M; Wick, Lukas Y; Harms, Hauke; Thullner, Martin

2016-04-01

Biodegradation of organic chemicals in the vapor phase of soils and vertical flow filters has gained attention as promising approach to clean up volatile organic compounds (VOC). The drivers of VOC biodegradation in unsaturated systems however still remain poorly understood. Here, we analyzed the processes controlling aerobic VOC biodegradation in a laboratory setup mimicking the unsaturated zone above a shallow aquifer. The setup allowed for diffusive vapor-phase transport and biodegradation of three VOC: non-deuterated and deuterated toluene as two compounds of highly differing biodegradability but (nearly) identical physical and chemical properties, and MTBE as (at the applied experimental conditions) non-biodegradable tracer and internal control. Our results showed for toluene an effective microbial degradation within centimeter VOC transport distances despite high gas-phase diffusivity. Degradation rates were controlled by the reactivity of the compounds while oxic conditions were found everywhere in the system. This confirms hypotheses that vadose zone biodegradation rates can be extremely high and are able to prevent the outgassing of VOC to the atmosphere within a centimeter range if compound properties and site conditions allow for sufficiently high degradation rates. Copyright © 2016 Elsevier Ltd. All rights reserved.

Cod Fractions In Mechanical-Biological Wastewater Treatment Plant

NASA Astrophysics Data System (ADS)

Płuciennik-Koropczuk, Ewelina; Jakubaszek, Anita; Myszograj, Sylwia; Uszakiewicz, Sylwia

2017-03-01

The paper presents results of studies concerning the designation of COD fraction in the raw, mechanically treated and biologically treated wastewater. The test object was a wastewater treatment plant with the output of over 20,000 PE. The results were compared with data received in the ASM models. During investigation following fractions of COD were determined: dissolved non-biodegradable SI, dissolved easily biodegradable SS, in organic suspension slowly degradable XS and in organic suspension non-biodegradable XI. Methodology for determining the COD fraction was based on the guidelines ATV-A 131. The real percentage of each fraction in total COD in raw wastewater are different from data received in ASM models.

Improved volatile fatty acid and biomethane production from lipid removed microalgal residue (LRμAR) through pretreatment.

PubMed

Suresh, Arumuganainar; Seo, Charles; Chang, Ho Nam; Kim, Yeu-Chun

2013-12-01

Renewable energy from lipid removed microalgal residues (LRμARs) serves as a promising tool for sustainable development of the microalgal biodiesel industry. Hence, in this study, LRμAR from Ettlia sp. was characterized for its physico-biochemical parameters, and applied to various pretreatment to increase the biodegradability and used in batch experiments for the production of volatile fatty acids (VFA) and biomethane. After various pretreatments, the soluble organic matters were increased at a maximum of 82% in total organic matters in alkali-autoclaved sample. In addition, VFA and methane production was enhanced by 30% and 40% in alkali-sonicated and alkali-autoclaved samples, respectively. Methane heating value was recovered at maximum of 6.6 MJ kg(-1)VS in alkali-autoclaved conditions with comparison to non-pretreated samples. The pretreatment remarkably improved LRμAR solubilization and enhanced VFA and biomethane production, which holds immense potential to eventually reduce the cost of algal biodiesel. Copyright © 2013 Elsevier Ltd. All rights reserved.

The size-reactivity continuum of major bioelements in the ocean.

PubMed

Benner, Ronald; Amon, Rainer M W

2015-01-01

Most of the carbon fixed in primary production is rapidly cycled and remineralized, leaving behind various forms of organic carbon that contribute to a vast reservoir of nonliving organic matter in seawater. Most of this carbon resides in dissolved molecules of varying bioavailability and reactivity, and aspects of the cycling of this carbon remain an enigma. The size-reactivity continuum model provides a conceptual framework for understanding the mechanisms governing the formation and mineralization of this carbon. In the seawater bioassay experiments that served as the original basis for this model, investigators observed that larger size classes of organic matter were more bioavailable and more rapidly remineralized by microbes than were smaller size classes. Studies of the chemical composition and radiocarbon content of marine organic matter have further indicated that the complexity and age of organic matter increase with decreasing molecular size. Biodegradation processes appear to shape the size distribution of organic matter and the nature of the small dissolved molecules that persist in the ocean.

Kinetics of natural organic matter (NOM) removal during drinking water biofiltration using different NOM characterization approaches.

PubMed

Chen, Fei; Peldszus, Sigrid; Elhadidy, Ahmed M; Legge, Raymond L; Van Dyke, Michele I; Huck, Peter M

2016-11-01

To better understand biofiltration, concentration profiles of various natural organic matter (NOM) components throughout a pilot-scale drinking water biofilter were investigated using liquid chromatography - organic carbon detection (LC-OCD) and fluorescence excitation and emission matrices (FEEM). Over a 2 month period, water samples were collected from six ports at different biofilter media depths. Results showed substantial removal of biopolymers (i.e. high molecular weight (MW) NOM components as characterized by LC-OCD) and FEEM protein-like materials, but low removal of humic substances, building blocks and low MW neutrals and low MW acids. For the first time, relative biodegradability of different NOM components characterized by LC-OCD and FEEM approaches were investigated across the entire MW range and for different fluorophore compositions, in addition to establishing the biodegradation kinetics. The removal kinetics for FEEM protein-like materials were different than for the LC-OCD-based biopolymers, illustrating the complementary nature of the LC-OCD and FEEM approaches. LC-OCD biopolymers (both organic carbon and organic nitrogen) and FEEM protein-like materials were shown to follow either first or second order biodegradation kinetics. Due to the low percent removal and small number of data points, the performance of three kinetic models was not distinguishable for humic substances. Pre-filtration of samples for FEEM analyses affected the removal behaviours and/or kinetics especially of protein-like materials which was attributed to the removal of the colloidal/particulate materials. Copyright © 2016 Elsevier Ltd. All rights reserved.

A case study on the method-induced difference in the chemical properties and biodegradability of soil water extractable organic carbon of a granitic forest soil.

PubMed

Wu, Yue; Jiang, Ying

2016-09-15

Water extractable organic carbon (WEOC) plays important roles in soil dissolved organic matter (DOM) research. In the present study, we have detected the chemical properties and biodegradability of WEOC obtained from one granitic forest soil with four commonly used or suggested extraction methods, to study the potential methodological influence in soil DOM research. Results showed great difference in both chemical properties and biodegradation of WEOC from various methods. For the chosen soil, compared to that from fresh soil, WEOC from dried soil contained large proportion of HIN, Base fractions and labile O-alkyl components which might be derived from microbial cell lysis, and showed low fluorescence characteristics, exhibiting great biodegradability. Similarly, WEOC extracted under low temperature and short time conditions showed low fluorescence characteristics and exhibited considerable biodegradability. Conversely, WEOC, which might be potentially subjected to decomposition and loss during extraction, contained higher percentages of HOA fractions and aromatic alkyl and aryl components, and showed high fluorescence characteristics, exhibiting low biodegradability. WEOC extracted in moderate time and temperature showed moderate biodegradability. These method-induced differences implied the direct comparison of the results from similar works is difficult, as we considered here a specific forest soil and other authors other soil types and uses. However, the complexity in comparison reminds that the methodological influence be paid more attention in future soil WEOC researches. Copyright © 2016 Elsevier B.V. All rights reserved.

The effect of humic acids on biodegradation of polycyclic aromatic hydrocarbons depends on the exposure regime.

PubMed

Tejeda-Agredano, Maria-Carmen; Mayer, Philipp; Ortega-Calvo, Jose-Julio

2014-01-01

Binding of polycyclic aromatic hydrocarbons (PAHs) to dissolved organic matter (DOM) can reduce the freely dissolved concentration, increase apparent solubility or enhance diffusive mass transfer. To study the effects of DOM on biodegradation, we used phenanthrene and pyrene as model PAHs, soil humic acids as model DOM and a soil Mycobacterium strain as a representative degrader organism. Humic acids enhanced the biodegradation of pyrene when present as solid crystals but not when initially dissolved or provided by partitioning from a polymer. Synchronous fluorescence spectrophotometry, scintillation counting and a microscale diffusion technique were applied in order to determine the kinetics of dissolution and diffusive mass transfer of pyrene. We suggest that humic acids can enhance or inhibit biodegradation as a result of the balance of two opposite effects, namely, solubilization of the chemicals on the one hand and inhibition of cell adhesion to the pollutant source on the other. Copyright © 2013 Elsevier Ltd. All rights reserved.

Aerobic biodegradation of a nonylphenol polyethoxylate and toxicity of the biodegradation metabolites.

PubMed

Jurado, Encarnación; Fernández-Serrano, Mercedes; Núñez-Olea, Josefa; Lechuga, Manuela

2009-09-01

In this paper a study was made of the biodegradation of a non-ionic surfactant, a nonylphenol polyethoxylate, in biodegradability tests by monitoring the residual surfactant matter. The influence of the concentration on the extent of primary biodegradation, the toxicity of biodegradation metabolites, and the kinetics of degradation were also determined. The primary biodegradation was studied at different initial concentrations: 5, 25 and 50 mg/L, (at sub-and supra-critical micelle concentration). The NPEO used in this study can be considered biodegradable since the primary biodegradation had already taken place (a biodegradation greater than 80% was found for the different initial concentration tested). The initial concentration affected the shape of the resulting curve, the mean biodegradation rate and the percentage of biodegradation reached (99% in less than 8 days at 5 mg/L, 98% in less than 13 days at 25 mg/L and 95% in 14 days at 50 mg/L). The kinetic model of Quiroga and Sales (1991) was applied to predict the biodegradation of the NPEO. The toxicity value was measured as EC(20) and EC(50). In addition, during the biodegradation process of the surfactant a toxicity analysis was made of the evolution of metabolites generated, confirming that the subproducts of the biodegradation process were more toxic than the original.

Effects of Cu2+ and humic acids on degradation and fate of TBBPA in pure culture of Pseudomonas sp. strain CDT.

PubMed

Ma, Yini; Zhao, Yingying; Wang, Yongfeng; Li, Xiangzhen; Sun, Feifei; Corvini, Phillippe Francois-Xavier; Ji, Rong

2017-12-01

Soil contamination with tetrabromobisphenol A (TBBPA) has caused great concerns; however, the presence of heavy metals and soil organic matter on the biodegradation of TBBPA is still unclear. We isolated Pseudomonas sp. strain CDT, a TBBPA-degrading bacterium, from activated sludge and incubated it with 14 C-labeled TBBPA for 87 days in the absence and presence of Cu 2+ and humic acids (HA). TBBPA was degraded to organic-solvent extractable (59.4%±2.2%) and non-extractable (25.1%±1.3%) metabolites, mineralized to CO 2 (4.8%±0.8%), and assimilated into cells (10.6%±0.9%) at the end of incubation. When Cu 2+ was present, the transformation of extractable metabolites into non-extractable metabolites and mineralization were inhibited, possibly due to the toxicity of Cu 2+ to cells. HA significantly inhibited both dissipation and mineralization of TBBPA and altered the fate of TBBPA in the culture by formation of HA-bound residues that amounted to 22.1%±3.7% of the transformed TBBPA. The inhibition from HA was attributed to adsorption of TBBPA and formation of bound residues with HA via reaction of reactive metabolites with HA molecules, which decreased bioavailability of TBBPA and metabolites in the culture. When Cu 2+ and HA were both present, Cu 2+ significantly promoted the HA inhibition on TBBPA dissipation but not on metabolite degradation. The results provide insights into individual and interactive effects of Cu 2+ and soil organic matter on the biotransformation of TBBPA and indicate that soil organic matter plays an essential role in determining the fate of organic pollutants in soil and mitigating heavy metal toxicity. Copyright © 2017. Published by Elsevier B.V.

RIVERBANK FILTRATION: EFFECT OF GROUND PASSAGE ON NOM CHARACTER

EPA Science Inventory

Research was conducted to explore the effect of underground travel on the character of the natural organic matter (NOM) originating from the river water source during riverbank filtration (RBF) at three Midwestern US drinking water utilities. Measurements of biodegradable dissolv...

Insight into metabolic and cometabolic activities of autotrophic and heterotrophic microorganisms in the biodegradation of emerging trace organic contaminants.

PubMed

Tran, Ngoc Han; Urase, Taro; Ngo, Huu Hao; Hu, Jiangyong; Ong, Say Leong

2013-10-01

Many efforts have been made to understand the biodegradation of emerging trace organic contaminants (EOCs) in the natural and engineered systems. This review summarizes the current knowledge on the biodegradation of EOCs while having in-depth discussion on metabolism and cometabolism of EOCs. Biodegradation of EOCs is mainly attributed to cometabolic activities of both heterotrophic and autotrophic microorganisms. Metabolism of EOCs can only be observed by heterotrophic microbes. Autotrophic ammonia oxidizing bacteria (AOB) and ammonia oxidizing archaeal (AOA) cometabolize a variety of EOCs via the non-specific enzymes, such as ammonia monooxygenase (AMO). Higher biodegradation of EOCs is often noted under nitrification at high ammonia loading rate. The presence of a growth substrate promotes cometabolic biodegradation of EOCs. Potential strategies for enhancing the biodegradation of EOCs were also proposed in this review. Copyright © 2013 Elsevier Ltd. All rights reserved.

Biodegradation of dissolved humic substances by fungi.

PubMed

Collado, Sergio; Oulego, Paula; Suárez-Iglesias, Octavio; Díaz, Mario

2018-04-01

Humic and fulvic acids constitute humic substances, a complex mixture of many different acids containing carboxyl and phenolate groups, which are not only the principal soil fertility factors but also the main pollutants present in landfill leachates or natural organic matter in water. Due to their low bacterial biodegradability, fungal biodegradation processes are key for their removal. The present study compiles and comments all the available literature on decomposition of aqueous humic substances by fungi or by their extracellular enzymes alone, focusing on the influence of the reaction conditions. The biodegradation extent mainly depends on the characteristics and concentration of the humic compounds, the type of microorganisms selected, the inoculation mode, the C and N sources, the presence of certain chemicals in the medium, the availability of oxygen, the temperature, and the pH.

Removal of non-biodegradable organic matter from landfill leachates by adsorption.

PubMed

Rodríguez, J; Castrillón, L; Marañón, E; Sastre, H; Fernández, E

2004-01-01

Leachates produced at the La Zoreda landfill in Asturias, Spain, were recirculated through a simulated landfill pilot plant. Prior to recirculation, three loads of different amounts of Municipal Solid Waste (MSW) were added to the plant, forming in this way consecutive layers. When anaerobic digestion was almost completed, the leachates from the landfill were recirculated. After recirculation, a new load of MSW was added and two new recirculations were carried out. The organic load of the three landfill leachates recirculated through the anaerobic pilot plant decreased from initial values of 5108, 3782 and 2560 mg/l to values of between 1500 and 1600 mg/l. Despite achieving reductions in the organic load of the leachate, a residual organic load still remained that was composed of non-biodegradable organic constituents such as humic substances. Similar values of the chemical oxygen demand (COD) were obtained when the landfill leachate was treated by a pressurised anoxic-aerobic process followed by ultrafiltration. After recirculation through the pilot plant, physico-chemical treatment was carried out to reduce the COD of the leachate. The pH of the leachate was decreased to a value of 1.5 to precipitate the humic fraction, obtaining a reduction in COD of about 13.5%. The supernatant liquid was treated with activated carbon and different resins, XAD-8, XAD-4 and IR-120. Activated carbon presented the highest adsorption capacities, obtaining COD values for the treated leachate in the order of 200mg/l. Similar results were obtained when treating with activated carbon, the leachate from the biological treatment plant at the La Zoreda landfill; in this case without decreasing the pH.

Microbial activity in Alaskan taiga soils contaminated by crude oil in 1976

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

Monroe, E.M.; Lindstrom, J.E.; Brown, E.J.

1995-12-31

Biodegradation, often measured via microbial activity, includes destruction of environmental pollutants by living microorganisms and is dependent upon many physical and chemical factors. Effects of mineral nutrients and organic matter on biodegradation of Prudhoe Bay crude oil were investigated at a nineteen-year-old oil spill site in Alaskan taiga. Microcosms of two different soil types from the spill site; one undeveloped soil with forest litter and detritus (O horizon) and one more developed with lower organic content (A horizon), were treated with various nitrogen and phosphorus amendments, and incubated for up to six weeks. Each microcosm was sampled periodically and assayedmore » for hydrocarbon mineralization potential using radiorespirometry, for total carbon dioxide respired using gas chromatography, and for numbers of hydrocarbon-degrading bacteria and heterotrophic bacteria using most probable number counting techniques. Organic matter in the O horizon soil along with combinations of mineral nutrients were found to stimulate microbial activity. No combination of mineral nutrient additions to the A horizon soil stimulated any of the parameters above those measured in control microcosms. The results of this study indicate that adding mineral nutrients and tilling the O horizon into the A horizon of subarctic soils contaminated with crude oil, would stimulate microbial activity, and therefore the biodegradation potential, ultimately increasing the rate of destruction of crude oil in these soils.« less

The possibility of useful usage of biodegradation products of sunflower plants.

PubMed

Kaya, Yusuf; Sengül, Meryem; Ogütçü, Hatice; Algur, Omer Faruk

2006-03-01

Heads of sunflower (Helianthus annuus L.) were first biodegraded at 55 degrees C by their microflora. Biodegradation products of sunflower heads (BPSH) were analyzed. They were found to contain 9.77% dry matter, 3.98% total ash, 3.18% crude protein and 5.75% total organic matter. BOD load was determined as 4.80 g/100 g. Subsequently, the effects of BPSH at various concentrations (1.0%, 2.5%, 10% and 100%) on the seed germination and some growth parameters of Phaseolus vulgaris L., Cicer arietinum L. and Triticum vulgare L. were investigated. The percentages of seed germination and germination index of seeds were similar between the control and 1.0% and 2.5% BPSH groups, but these values decreased at higher concentrations. On the other hand, growth of the seedlings gradually increased up to a concentration of 10% BPSH and decreased at 100% concentration. As a result, at concentrations up to 10% the product was found to be beneficial for growth of plants.

Integrated ozone and biotreatment of pulp mill effluent and changes in biodegradability and molecular weight distribution of organic compounds.

PubMed

Bijan, Leila; Mohseni, Madjid

2005-10-01

The overall effectiveness of integrating ozonation with biological treatment on the biodegradability enhancement and recalcitrant organic matter (ROM) removal from pulp mill alkaline bleach plant effluent was investigated. Ozonation was performed in a semi-batch bubble column reactor at pH of 11 and 4.5. Batch biological treatment was conducted in shake flasks. Samples obtained during the treatments were monitored for BOD5, COD, TOC, and molecular weight distribution. At an ozone dosage of 0.7-0.8 mg O3/mL wastewater, integrated treatment showed about 30% higher TOC mineralization compared to individual ozonation or biotreatment. Ozone treatment enhanced the biodegradability of the effluent (monitored as 21% COD reduction and 13% BOD5 enhancement), allowing for a higher removal of pollutants. The conversion of high molecular weight (HMW) to low molecular weight (LMW) compounds was an important factor in the overall biodegradability enhancement of the alkaline effluent. The overall biodegradability of the LMW compounds did not change over the course of ozonation, but it increased from 5% to 50% (measured as COD removal) for the HMW portion. Ozonation at pH of 11 was more effective than that at pH of 4.5 in terms of generating more biodegradable compounds.

The Environmental Behavior of Methylene-4,4'-dianiline.

PubMed

Schupp, Thomas; Allmendinger, Hans; Boegi, Christian; Bossuyt, Bart T A; Hidding, Bjoern; Shen, Summer; Tury, Bernard; West, Robert J

2018-06-24

Methylene-4,4'-dianiline (MDA, CAS-No. 101-77-9) is a high production volume intermediate that is mainly processed to diisocyanates and finally polyurethanes. This review summarizes available data concerning the environmental behavior. When released into the environment, MDA distributes into water and subsequently sediment and soil compartments; the air is of little relevance, owed to the low vapor pressure and short atmospheric half-life, which renders MDA non-critical for long-range transport. Biodegradation data present a diverged picture; in some tests, MDA is not readily biodegradable or even not inherent biodegradable; in other tests, MDA turned out to be readily biodegradable (but failing the 10-d window). The history and composition of the inoculum used for testing seem to play an important role, which is underlined by good test results with adapted inoculum. In soil, initially a rapid mineralization is observed, which slows down within the first days due to competitive chemical absorption. The latter results in degradation rates comparable to that of natural organic matter. Under anaerobic conditions, mineralization is poor. Irreversible chemisorption occurs unless soils/sediments are highly reduced. Half-lives due to primary decay do not indicate MDA to be persistent according to the regulatory guidance used in then EU, Canada, or the USA; in Japan, however, due to test results in MITI degradation tests, MDA would be regarded as persistent. The identification of microbial MDA metabolites deserves further research. MDA is not bioaccumulative, but it is toxic to aquatic organisms and mammals. MDA in pore water of soils is rapidly adsorbed on the surface of plant roots. Test runs were too short to draw a final conclusion with regards to transport to stem, leaves, and fruits. Data from structurally similar compounds indicate that such transport would account for less than 1% of the root-adsorbed material.

Improved anaerobic digestion of a thermally pretreated mixture of physicochemical sludge; broiler excreta and sugar cane wastes (SCW): Effect on organic matter solubilization, biodegradability and bioenergy production.

PubMed

Nava-Valente, Noemí; Alvarado-Lassman, Alejandro; Nativitas-Sandoval, Liliana S; Mendez-Contreras, Juan M

2016-01-01

Thermal pretreatment effect of a mixture of organic wastes (physicochemical sludge, excreta of broiler chickens and sugarcane wastes (SCW)) in the solubilization and biodegradability organic matter as well as bioenergy production by anaerobic digestion was evaluated. Two different mixtures of physicochemical sludge, excreta of broiler chickens and SCW (70%, 15%, 15% and 60%, 20%, 20% of VS, respectively) were treated at different temperatures (80 °C, 85 °C and 90 °C) and contact time (30, 60 and 90 min). Results indicate that, organic matter solubilization degree increased from 1.14 to 6.56%; subsequently, in the anaerobic digestion process, an increase of 50% in the volatile solids removal and 10% in biogas production was observed, while, retention time decreased from 23 up to 9 days. The results obtained were similar to pilot-scale. In both experimental scales it showed that the synergy produced by the simultaneous anaerobic digestion of different substrates could increase bioenergy production up to 1.3 L bio g(-1) VS removed and 0.82 L CH4 g(-1) VS removed. The treatment conditions presented in this study allow for large residue quantities to be treated and large bioenergy quantities to be produced (10% higher than during conventional treatment) without increasing the anaerobic digester volume.

Determination of the origin of dissolved inorganic carbon in groundwater around a reclaimed landfill in Otwock using stable carbon isotopes

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

Porowska, Dorota, E-mail: dorotap@uw.edu.pl

Highlights: • Research showed the origin of DIC in the groundwater around a reclaimed landfill. • Carbon isotope was used to evaluate the contributions of carbon from different sources. • The leachate-contaminated water was isotopically distinct from the natural groundwater. • DIC in the natural groundwater comes from organic matter and dissolution of carbonates. • In the contaminated water, DIC comes from organic matter in the aquifer and landfill. - Abstract: Chemical and isotopic analyses of groundwater from piezometers located around a reclaimed landfill in Otwock (Poland) were performed in order to trace the origin of dissolved inorganic carbon (DIC)more » in the groundwater. Due to differences in the isotopic composition of carbon from different sources, an analysis of stable carbon isotopes in the groundwater, together with the Keeling plot approach and a two-component mixing model allow us to evaluate the relative contributions of carbon from these sources in the groundwater. In the natural (background) groundwater, DIC concentrations and the isotopic composition of DIC (δ{sup 13}C{sub DIC}) comes from two sources: decomposition of organic matter and carbonate dissolution within the aquifer sediments, whereas in the leachate-contaminated groundwater, DIC concentrations and δ{sup 13}C{sub DIC} values depend on the degradation of organic matter within the aquifer sediments and biodegradation of organic matter stored in the landfill. From the mixing model, about 4–54% of the DIC pool is derived from organic matter degradation and 96–46% from carbonate dissolution in natural conditions. In the leachate-contaminated groundwater, about 20–53% of the DIC is derived from organic matter degradation of natural origin and 80–47% from biodegradation of organic matter stored in the landfill. Partial pressure of CO{sub 2} (P CO{sub 2}) was generally above the atmospheric, hence atmospheric CO{sub 2} as a source of carbon in DIC pool was negligible in the aquifer. P CO{sub 2} values in the aquifer in Otwock were always one to two orders of magnitude above the atmospheric P CO{sub 2}, and thus CO{sub 2} escaped directly into the vadose zone.« less

Improvement of the analysis of the biochemical oxygen demand (BOD) of Mediterranean seawater by seeding control.

PubMed

Simon, F Xavier; Penru, Ywann; Guastalli, Andrea R; Llorens, Joan; Baig, Sylvie

2011-07-15

Biochemical oxygen demand (BOD) is a useful parameter for assessing the biodegradability of dissolved organic matter in water. At the same time, this parameter is used to evaluate the efficiency with which certain processes remove biodegradable natural organic matter (NOM). However, the values of BOD in seawater are very low (around 2 mgO(2)L(-1)) and the methods used for its analysis are poorly developed. The increasing attention given to seawater desalination in the Mediterranean environment, and related phenomena such as reverse osmosis membrane biofouling, have stimulated interest in seawater BOD close to the Spanish coast. In this study the BOD analysis protocol was refined by introduction of a new step in which a critical quantity of autochthonous microorganisms, measured as adenosine triphosphate, is added. For the samples analyzed, this improvement allowed us to obtain reliable and replicable BOD measurements, standardized with solutions of glucose-glutamic acid and acetate. After 7 days of analysis duration, more than 80% of ultimate BOD is achieved, which in the case of easily biodegradable compounds represents nearly a 60% of the theoretical oxygen demand. BOD(7) obtained from the Mediterranean Sea found to be 2.0±0.3 mgO(2)L(-1) but this value decreased with seawater storage time due to the rapid consumption of labile compounds. No significant differences were found between two samples points located on the Spanish coast, since their organic matter content was similar. Finally, the determination of seawater BOD without the use of inoculum may lead to an underestimation of BOD. Copyright © 2011 Elsevier B.V. All rights reserved.

Compost mixture influence of interactive physical parameters on microbial kinetics and substrate fractionation.

PubMed

Mohajer, Ardavan; Tremier, Anne; Barrington, Suzelle; Teglia, Cecile

2010-01-01

Composting is a feasible biological treatment for the recycling of wastewater sludge as a soil amendment. The process can be optimized by selecting an initial compost recipe with physical properties that enhance microbial activity. The present study measured the microbial O(2) uptake rate (OUR) in 16 sludge and wood residue mixtures to estimate the kinetics parameters of maximum growth rate mu(m) and rate of organic matter hydrolysis K(h), as well as the initial biodegradable organic matter fractions present. The starting mixtures consisted of a wide range of moisture content (MC), waste to bulking agent (BA) ratio (W/BA ratio) and BA particle size, which were placed in a laboratory respirometry apparatus to measure their OUR over 4 weeks. A microbial model based on the activated sludge process was used to calculate the kinetic parameters and was found to adequately reproduced OUR curves over time, except for the lag phase and peak OUR, which was not represented and generally over-estimated, respectively. The maximum growth rate mu(m), was found to have a quadratic relationship with MC and a negative association with BA particle size. As a result, increasing MC up to 50% and using a smaller BA particle size of 8-12 mm was seen to maximize mu(m). The rate of hydrolysis K(h) was found to have a linear association with both MC and BA particle size. The model also estimated the initial readily biodegradable organic matter fraction, MB(0), and the slower biodegradable matter requiring hydrolysis, MH(0). The sum of MB(0) and MH(0) was associated with MC, W/BA ratio and the interaction between these two parameters, suggesting that O(2) availability was a key factor in determining the value of these two fractions. The study reinforced the idea that optimization of the physical characteristics of a compost mixture requires a holistic approach. 2010 Elsevier Ltd. All rights reserved.

Improved chemometric methodologies for the assessment of soil carbon sequestration mechanisms

NASA Astrophysics Data System (ADS)

Jiménez-González, Marco A.; Almendros, Gonzalo; Álvarez, Ana M.; González-Vila, Francisco J.

2016-04-01

The factors involved soil C sequestration, which is reflected in the highly variable content of organic matter in the soils, are not yet well defined. Therefore, their identification is crucial for understanding Earth's biogeochemical cycle and global change. The main objective of this work is to contribute to a better qualitative and quantitative assessment of the mechanisms of organic C sequestration in the soil, using omic approaches not requiring the detailed knowledge of the structure of the material under study. With this purpose, we have carried out a series of chemometric approaches on a set of widely differing soils (35 representative ecosystems). In an exploratory phase, we used multivariate statistical models (e.g., multidimensional scaling, discriminant analysis with automatic backward variable selection…) to analyze arrays of more than 200 independent soil variables (physicochemical, spectroscopic, pyrolytic...) in order to select those factors (descriptors or proxies) that explain most of the total system variance (content and stability of the different C forms). These models showed that the factors determining the stabilization of organic material are greatly dependent on the soil type. In some cases, the molecular structure of organic matter seemed strongly correlated with their resilience, while in other soil types the organo-mineral interactions played a significant bearing on the accumulation of selectively preserved C forms. In any case, it was clear that the factors driving the resilience of organic matter are manifold and not exclusive. Consequently, in a second stage, prediction models of the soil C content and their biodegradability (laboratory incubation experiments) were carried out by massive data processing by partial least squares (PLS) regression of data from Py-GC-MS and Py-MS. In some models, PLS was applied to a matrix of 150 independent variables corresponding to major pyrolysis compounds (peak areas) from the 35 samples of whole soils. The variable importance in the projection (VIP) histogram obtained from this treatment (total C and total mineralization coefficients as dependent variables) illustrated the contribution of the individual compounds to the total inertia of the models (e.g., carbohydrate-derived compounds, methoxyphenols, or specific alkylbenzenes were relevant in explaining the total quality and the biodegradation rates of the organic matter). Further simplified models consisting of direct PLS analysis of the debugged ion matrix calculated by averaging all ions (45 - 250 amu) in the whole chromatographic area in the 5-60 min range (here referred to as 'rebuilt MS spectra' or 'Py-MS spectra' when obtained connecting directly the pyrolyser to the MS detector through suitable interfaces) were carried out. The above three approaches coincided in pointing out that C sequestration behave as an emergent soil property depending on the complexity of its progressive molecular levels. Most of the total variance is explained by specific assemblages of variables, strongly depending on the soil types. On the other hand, chemical biodiversity (e.g., Shannon indices or coefficients from multivariate data models) behaved as a common background in the prediction models including very different soil types. In fact, assessment of chemodiversity of the pyrolytic compound assemblages (or the Py-MS ion data) would represent a valid clue for the assessment of the extent to which the original biomass has been diagenetically reworked into chaotic structures with non-repeatable units, providing a useful proxy to forecast at least a portion of the total variance in the soil organic matter biodegradability.

A critical review on characterization strategies of organic matter for wastewater and water treatment processes.

PubMed

Tran, Ngoc Han; Ngo, Huu Hao; Urase, Taro; Gin, Karina Yew-Hoong

2015-10-01

The presence of organic matter (OM) in raw wastewater, treated wastewater effluents, and natural water samples has been known to cause many problems in wastewater treatment and water reclamation processes, such as treatability, membrane fouling, and the formation of potentially toxic by-products during wastewater treatment. This paper summarizes the current knowledge on the methods for characterization and quantification of OM in water samples in relation to wastewater and water treatment processes including: (i) characterization based on the biodegradability; (ii) characterization based on particle size distribution; (iii) fractionation based on the hydrophilic/hydrophobic properties; (iv) characterization based on the molecular weight (MW) size distribution; and (v) characterization based on fluorescence excitation emission matrix. In addition, the advantages, disadvantages and applications of these methods are discussed in detail. The establishment of correlations among biodegradability, hydrophobic/hydrophilic fractions, MW size distribution of OM, membrane fouling and formation of toxic by-products potential is highly recommended for further studies. Copyright © 2015 Elsevier Ltd. All rights reserved.

An experimental model of COD abatement in MBBR based on biofilm growth dynamic and on substrates' removal kinetics.

PubMed

Siciliano, Alessio; De Rosa, Salvatore

2016-08-01

In this study, the performance of a lab-scale Moving Bed Biofilm Reactor (MBBR) under different operating conditions was analysed. Moreover, the dependence of the reaction rates both from the concentration and biodegradability of substrates and from the biofilm surface density, by means of several batch kinetic tests, was investigated. The reactor controls exhibited an increasing COD (Chemical Oxygen Demand) removal, reaching maximum yields (close to 90%) for influent loadings of up to12.5 gCOD/m(2)d. From this value, the pilot plant performance decreased to yields of only about 55% for influent loadings greater than 16 gCOD/m(2)d. In response to the influent loading increase, the biofilm surface density exhibited a logistic growing trend until reaching a maximum amount of total attached solids of about 9.5 g/m(2). The kinetic test results indicated that the COD removal rates for rapidly biodegradable, rapidly hydrolysable and slowly biodegradable substrates were not affected by the organic matter concentrations. Instead, first-order kinetics were detected with respect to biofilm surface density. The experimental results permitted the formulation of a mathematical model to predict the MBBR organic matter removal efficiency. The validity of the model was successfully tested in the lab-scale plant.

Effect of aluminium on dissolved organic matter mineralization in an allophanic and kaolinitic temperate rain forest soil

NASA Astrophysics Data System (ADS)

Merino, Carolina; Matus, Francisco; Fontaine, Sebastien

2016-04-01

Aluminium (Al) and it influence on the mineralization of dissolved organic matter (DOM) and thus on carbon (C) sequestration in forest soils is poorly understood. We hypothesized that an addition of Al to the soil solution beyond a molar Al:C ratio of 0.1, induces precipitation of the organic matter which leads to an excess Al in the soil solution causing an inhibitory effect for growing microorganisms. We investigated the effect of Al concentrations for the potential of C biodegradation at different Al:C ratios from DOM and Ah mineral soil horizons from two temperate rain forest soils from southern Chile. Dissolved organic matter and surface mineral horizons were incubated with initial molar Al:C ratio from 0.08 to 1.38 found under at field conditions. Mineralization was quantified by measurement of C-CO2 evolved during 15 days. Increasing the initial Al:C ratio > 0.12, led to a considerable reduction in mineralization (up to 70%). For Al:C ratio < 0.12, the mineralization rates from DOM and mineral soils were unaffected. Consequently, there would be a considerable reduction in the biodegradation of DOM and thus an increased in the C sequestration in mineral soils with molar Al:C ratio > 0.12. The observed DOM losses in the stream water of pristine southern forests can be explained by increasing the bioavailability of organic C for Al:C ratio < 0.12. Aluminium concentration had a marked effect at the spectral ART-FTIR bands assigned to cellulose-like and aromatic compounds in Ah mineral soil, diminishing the mineralization. The present results were also confirmed by the Al fluorescence using a confocal microscopy.

Enhanced micropollutant biodegradation and assessment of nitrous oxide concentration reduction in wastewater treated by acclimatized sludge bioaugmentation.

PubMed

Boonnorat, Jarungwit; Techkarnjanaruk, Somkiet; Honda, Ryo; Ghimire, Anish; Angthong, Sivakorn; Rojviroon, Thammasak; Phanwilai, Supaporn

2018-05-11

This research investigated the micropollutant biodegradation and nitrous oxide (N 2 O) concentration reduction in high strength wastewater treated by two-stage activated sludge (AS) systems with (bioaugmented) and without (non-bioaugmented) acclimatized sludge bioaugmentation. The bioaugmented and non-bioaugmented systems were operated in parallel for 228 days, with three levels of concentrations of organics, nitrogen, and micropollutants in the influent: conditions 1 (low), 2 (moderate), and 3 (high). The results showed that, under condition 1, both systems efficiently removed the organic and nitrogen compounds. However, the bioaugmented system was more effective in the micropollutant biodegradation and N 2 O concentration reduction than the non-bioaugmented one. Under condition 2, the nitrogen and micropollutant biodegradation efficiency of the non-bioaugmented system slightly decreased, while the N 2 O concentration declined in the bioaugmented system. Under condition 3, the treatment performance and N 2 O concentration abatement were substantially lowered as the compounds concentration increased. Further analysis also showed that the acclimatized sludge bioaugmentation increased the bacterial diversity in the system. In essence, the acclimatized sludge bioaugmentation strategy was highly effective for the influent with low compounds concentration, achieving the organics and nitrogen removal efficiencies of 92-97%, relative to 71-97% of the non-bioaugmented system. The micropollutant treatment efficiency of the bioaugmented system under condition 1 was 75-92%, indicating significant improvement in the treatment performance (p < 0.05), compared with 60-79% of the non-bioaugmented system. Copyright © 2018 Elsevier B.V. All rights reserved.

Biodegradation of naphthalene-2-sulfonic acid present in tannery wastewater by bacterial isolates Arthrobacter sp. 2AC and Comamonas sp. 4BC.

PubMed

Song, Zhi; Edwards, Suzanne R; Burns, Richard G

2005-06-01

Two bacterial strains, 2AC and 4BC, both capable of utilizing naphthalene-2-sulfonic acid (2-NSA) as a sole source of carbon, were isolated from activated sludges previously exposed to tannery wastewater. Enrichments were carried out in mineral salt medium (MSM) with 2-NSA as the sole carbon source. 16S rDNA sequencing analysis indicated that 2AC is an Arthrobacter sp. and 4BC is a Comamonas sp. Within 33 h, both isolates degraded 100% of 2-NSA in MSM and also 2-NSA in non-sterile tannery wastewater. The yield coefficient was 0.33 g biomass dry weight per gram of 2-NSA. A conceptual model, which describes the aerobic transformation of organic matter, was used for interpreting the biodegradation kinetics of 2-NSA. The half-lives for 2-NSA, at initial concentrations of 100 and 500 mg/l in MSM, ranged from 20 h (2AC) to 26 h (4BC) with lag-phases of 8 h (2AC) and 12 h (4BC). The carbon balance indicates that 75-90% of the initial TOC (total organic carbon) was mineralized, 5-20% remained as DOC (dissolved organic carbon) and 3-10% was biomass carbon. The principal metabolite of 2-NSA biodegradation (in both MSM and tannery wastewater) produced by Comamonas sp. 4BC had a MW of 174 and accounted for the residual DOC (7.0-19.0% of the initial TOC and 66% of the remaining TOC). Three to ten percent of the initial TOC (33% of the remaining TOC) was associated with biomass. The metabolite was not detected when Arthrobacter sp. 2AC was used, and a lower residual DOC and biomass carbon were recorded. This suggests that the two strains may use different catabolic pathways for 2-NSA degradation. The rapid biodegradation of 2-NSA (100 mg/l) added to non-sterile tannery wastewater (total 2-NSA, 105 mg/l) when inoculated with either Arthrobacter 2AC or Comamonas 4BC showed that both strains were able to compete with the indigenous microorganisms and degrade 2-NSA even in the presence of alternate carbon sources (DOC in tannery wastewater = 91 mg/l). The results provide information useful for the rational design of bioreactors for tannery wastewater treatment.

Biodegradation of organic matters from mixed unshredded municipal solid waste through air convection before landfilling.

PubMed

Mahar, Rasool B; Liu, Jianguo; Yue, Dongbei; Nie, Yongfeng

2007-01-01

Landfilling is a dominant municipal solid waste (MSW) disposal method in most developing countries. In China, approximately 85% of the generated MSW is being disposed of in the landfills. The amount of MSW is growing rapidly with the rate of approximately 8-10% annually, which contains a high quantity of moisture and organic matters. The problems of leachate treatment and landfill gas (LFG) emissions are increasing gradually. Reducing the hazard before emplacement, pretreatment of MSW before landfilling has become very important for the conventional landfill. In this study, aerobic pretreatment of mixed MSW was used, and much attention has been given to the natural convection of air in the mixed and unshredded MSW for bioconversion of organic matter (OM). This study is an attempt to investigate aerobic pretreatment suitability for the mixed and unshredded MSW at Beijing. A pilot-scale aerobic pretreatment simulator (APS) was developed at Beishen Shu Landfill in Beijing. To work out the biodegradation of the OM in the APS, fresh and pretreated MSW samples were collected and analyzed for OM, moisture content, temperature, chemical oxygen demand, total organic carbon, carbon, nitrogen, hydrogen, lignocelluloses, and biochemical methane potential at various stages of the pretreatment. Furthermore, results of the fresh and pretreated MSW are compared. Significant reduction in the observed parameters of the pretreated waste samples is observed. This work demonstrates that pretreatment is significantly effective in reducing the landfill emissions that is leachate and LFG.

Co-biodrying of sewage sludge and organic fraction of municipal solid waste: Role of mixing proportions.

PubMed

Zhang, Difang; Luo, Wenhai; Yuan, Jing; Li, Guoxue

2018-04-26

This study investigated the performance of co-biodrying sewage sludge and organic fraction of municipal solid waste (OFMSW) at different proportions. Cornstalk was added at 15% (of total wet weight) as the bulking agent. Results show that increasing OFMSW percentage promoted the biodegradation of organic matter, thus enhancing the temperature integration value and water removal to above 75% during sludge and OFMSW co-biodrying. In particular, adding more OFMSW accelerated the biodegradation of soluble carbohydrates, lignins, lipids, and amylums, resulting in more organic loss and thus lower biodrying index (3.3-3.7 for 55-85% OFMSW). Water balance calculation indicated that evaporation was the main mechanism for water removal. Heat used for water evaporation was 37.7-48.6% of total heat consumption during co-biodrying. Our results suggest that sludge and OFMSW should be mixed equally for their efficient co-biodrying. Copyright © 2018 Elsevier Ltd. All rights reserved.

Biodegradable Sonobuoy Decelerators

DTIC Science & Technology

2015-06-01

material. Two materials studied were polyvinyl alcohol (PVOH) and polyhydroxyalkanoate (PHA). Single and multilayered PVOH films were evaluated as well...readiness point for technology transition. 15. SUBJECT TERMS biodegrade, decelerator, sonobuoy, polyvinyl alcohol, polyhydroxyalkanoate , marine...Center NGO non-governmental organizations NOAA National Oceanic and Atmospheric Administration PHA polyhydroxyalkanoate PIA Parachute Industry

Understanding the anaerobic biodegradability of food waste: Relationship between the typological, biochemical and microbial characteristics.

PubMed

Fisgativa, Henry; Tremier, Anne; Le Roux, Sophie; Bureau, Chrystelle; Dabert, Patrick

2017-03-01

In this study, an extensive characterisation of food waste (FW) was performed with the aim of studying the relation between FW characteristics and FW treatability through an anaerobic digestion process. In addition to the typological composition (paper, meat, fruits, vegetables contents, etc) and the physicochemical characteristics, this study provides an original characterisation of microbial populations present in FW. These intrinsic populations can actively participate to aerobic and anaerobic degradation with the presence of Proteobacteria and Firmicutes species for the bacteria and of Ascomycota phylum for the fungi. However, the characterisation of FW bacterial and fungi community shows to be a challenge because of the biases generated by the non-microbial DNA coming from plant and by the presence of mushrooms in the food. In terms of relations, it was demonstrated that some FW characteristics as the density, the volatile solids and the fibres content vary as a function of the typological composition. No direct relationship was demonstrated between the typological composition and the anaerobic biodegradability. However, the Pearson's matrix results reveal that the anaerobic biodegradation potential of FW was highly related to the total chemical oxygen demand (tCOD), the total solid content (TS), the high weight organic matter molecules soluble in water (SOL W >1.5 kDa) and the C/N ratio content. These relations may help predicting FW behaviour through anaerobic digestion process. Finally, this study also showed that the storage of FW before collection, that could induce pre-biodegradation, seems to impact several biochemical characteristics and could improve the biodegradability of FW. Copyright © 2016 Elsevier Ltd. All rights reserved.

Fresh Kills leachate treatment and minimization study. Volume 3, Biodegradability, nitrification and denitrification: Final report

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

Fillos, J.; Khanbilvardi, R.

1993-09-01

The Fresh Kills Landfill is a 2400-acre site located on the western shore of Staten Island. The landfill is divided into several geographical sections, two of which, sections 1/9 and 6/7, will remain active for the near future. These sections will continue to produce leachate which will be collected and treated in an on-site facility. This volume presents the results of a series of leachate analyses and batch- and continuous-flow experiments designed to characterize the leachate and to develop loading criteria for a biological nitrogen removal process. The analyses showed that 57 percent of the organic matter in the leachatemore » falls below the 1,000 MW size while 14 percent is higher than 30,000 MW. Most of the organic matter is nonbiodegradable. Procedures applied to improve biodegradability, such as thermal and pH conditioning, and attempts to chemically oxidize the organic matter with ozone and hydrogen peroxide were not effective, demonstrating that the organic matter is stable and should persist indefinitely when released to the environment. However, biological nitrogen removal was extremely effective. Ammonia nitrification in excess of 99 percent was achieved in a sequencing batch reactor, using process loading rates in the range of 0.23 to 0.44 lb NH{sub 3}/lb MLVSS/day. Subsequent denitrification of the nitrites and nitrates required an external source of carbon. Methanol was used as the carbon source achieving complete denitrification in an anaerobic upflow reactor. Denitrification rates were measured in the range 62 to 125 lb NO{sub x}/1000 cu ft/day, with methanol to nitrogen ratio dosages in the rang 1.9 to 2.2 and retention time of approximately 10 hours.« less

Stabilization of polar soils organic matter: insights from 13-C NMR and ESR spectroscopy

NASA Astrophysics Data System (ADS)

Abakumov, Evgeny

2017-04-01

Polar soils play a key role in the global carbon balance, as they contain maximum stocks of soil organic matter (SOM) within the whole pedosphere. Low temperature and severe conditions provides the accumulation of large amounts of organic matter in permafrost soils over thousands of years. The quality and composition of organic matter of polar soils is underestimated. In order to better understand the implication of permafrost SOM to greenhouse gas emissions, an accurate knowledge of its spatial distribution, both in terms of quantity and quality (i.e. biodegradability, chemical composition and humification degree) is needed. The chemical composition of SOM determines its decomposability and, therefore, it determines the rate at which carbon may be transferred from soils to the atmosphere under warming conditions. Biodegradability of SOM has been related to humification degree, as more advanced stages in the humification process imply a depletion of the labile molecules, as well as an increase in the bulk aromaticity, which provides a higher stability of the SOM. Soils from Antarctic and different sectors of Arctic biome were investigated by 13-C NMR and electron spin resonance spectroscopy. It was shown, that the characteristic feature of polar soils humic acids is the dominance of aliphatic compounds on the aromatic one. This is related to the humification precursors component composition, namely to dominance of the remnants of lower plants, especially in Antarctic and low period of biological activity, which regulates the humification rate. Humic acids of Antarctic and various Arctic soils show the portion of aromatic components not more than 30 %. ESR spectroscopy shown that the concentration of free radicals is proportional to the humic acids stabilization degree. Less humified organic materials show the highest portion of free radical content, while the most developed soils and buried organic layers show decreased contents of free radicals. The database on soil organic matter composition of polar soil should be created with aim to evaluate current state of the humosphere and to provide the prognostic scenarios of possible mineralisation of humus.

Assessing the biodegradability of terrestrially-derived organic matter in Scottish sea loch sediments

NASA Astrophysics Data System (ADS)

Loh, P. S.; Miller, A. E. J.; Reeves, A. D.; Harvey, S. M.; Overnell, J.

2008-05-01

Lignin oxidation products, oxygen uptake rates, molar organic carbon to nitrogen (OC/N) ratio (from bulk elemental analysis) and Rp values (from loss on ignition experiments, the ratio of the refractory to total organic matter, OM) were determined for sediments along transects of Loch Creran and Loch Etive. Lignin data indicated the importance of riverine inputs contributing to land-derived carbon in the lochs as total lignin (Λ, mg/100 mg organic carbon, OC) decreased from 0.69 to 0.45 and 0.70 to 0.29 from the head to outside of Loch Creran and Loch Etive, respectively. In addition, significant correlations of lignin content against total OM and OC (p<0.05) also suggested a distinct contribution of terrestrial OM to carbon pools in the lochs. The general trend of decreasing oxygen uptake rates from the head (20.8 mmole m-2 day-1) to mouth (9.4 mmole m-2 day-1) of Loch Creran indicates decomposition of OM. Biodegradability of the sedimentary OM was also characterized by the increase of Rp values from the head to mouth of the lochs: 0.40 to 0.80 in Loch Etive and 0.43 to 0.63 in Loch Creran. Furthermore, the molar OC/N ratio decreased from 11.2 to 6.4 in Loch Creran, and from 17.5 to 8.2 in Loch Etive. Derived rate constants for OM degradation were found to decrease from LC0 to LC1, and increase from RE5 to RE6. This work demonstrates that oxygen uptake rates, Rp values and molar OC/N ratio are able to serve as useful proxies to indicate the biodegradability of sedimentary OM.

Safe biodegradable fluorescent particles

DOEpatents

Martin, Sue I [Berkeley, CA; Fergenson, David P [Alamo, CA; Srivastava, Abneesh [Santa Clara, CA; Bogan, Michael J [Dublin, CA; Riot, Vincent J [Oakland, CA; Frank, Matthias [Oakland, CA

2010-08-24

A human-safe fluorescence particle that can be used for fluorescence detection instruments or act as a safe simulant for mimicking the fluorescence properties of microorganisms. The particle comprises a non-biological carrier and natural fluorophores encapsulated in the non-biological carrier. By doping biodegradable-polymer drug delivery microspheres with natural or synthetic fluorophores, the desired fluorescence can be attained or biological organisms can be simulated without the associated risks and logistical difficulties of live microorganisms.

Removal of less biodegradable dissolved organic matters in water by superconducting magnetic separation with magnetic mesoporous carbon

NASA Astrophysics Data System (ADS)

Kondo, K.; Jin, T.; Miura, O.

2010-11-01

Less biodegradable dissolved organic matters in water as typified by humic substances are known as precursors of carcinogenic trihalomethanes, and are removed about 60% by current advanced water treatments. However, further increase of the removal ratio is demand. In this study, magnetic mesoporous carbon (MMPC), which can adsorb the substances physically and be efficiently collected by using superconducting high gradient magnetic separation (HGMS), has been synthesized with coconut-shell-based activated carbon and ferric nitrate solution by the gas activation method. The MMPC has the maximum magnetization value of 30.7 emu/g and an adsorption ability of 87% to 10 mg/L humic acid in a short time. The standard MMPC having a magnetization of 6.43 emu/g was able to be separated at magnetic field of 2 T. Used MMPC regained the adsorption ability to 93.1% by N2 reactivation heat treatment. These results show promise for application of current water treatments by superconducting HGMS, which is suitable for high-speed water treatment without secondary wastes.

A Review on Advanced Treatment of Pharmaceutical Wastewater

NASA Astrophysics Data System (ADS)

Guo, Y.; Qi, P. S.; Liu, Y. Z.

2017-05-01

The composition of pharmaceutical wastewater is complex, which is high concentration of organic matter, microbial toxicity, high salt, and difficult to biodegrade. After secondary treatment, there are still trace amounts of suspended solids and dissolved organic matter. To improve the quality of pharmaceutical wastewater effluent, advanced treatment is essential. In this paper, the classification of the pharmaceutical technology was introduced, and the characteristics of pharmaceutical wastewater effluent quality were summarized. The methods of advanced treatment of pharmaceutical wastewater were reviewed afterwards, which included coagulation and sedimentation, flotation, activated carbon adsorption, membrane separation, advanced oxidation processes, membrane separation and biological treatment. Meanwhile, the characteristics of each process were described.

Effects of ozonation pretreatment on natural organic matter and wastewater derived organic matter - Possible implications on the formation of ozonation by-products.

PubMed

Papageorgiou, Alexandros; Stylianou, Stylianos K; Kaffes, Pavlos; Zouboulis, Anastasios I; Voutsa, Dimitra

2017-03-01

The aim of this study was to investigate possible implications of natural and wastewater derived organic matter in river water that is subsequently used following treatment for drinking purposes. River water was subjected to lab-scale ozonation experiments under different ozone doses (0.1, 0.4, 0.8, 1.0 and 2.0 mgO 3 /mgC) and contact times (1, 3, 5, 8 and 10 min). Mixtures of river water with humic acids or wastewaters (sewage wastewater and secondary effluents) at different proportions were also ozonated. Dissolved organic carbon and biodegradable dissolved organic carbon concentrations as well as spectroscopic characteristics (UV absorbance and fluorescence intensities) of different types of dissolved organic matter and possible changes due to the ozonation treatment are presented. River water, humic substances and wastewater exhibited distinct spectroscopic characteristics that could serve for pollution source tracing. Wastewater impacted surface water results in higher formation of carbonyl compounds. However, the formation yield (μg/mgC) of wastewaters was lower than that of surface water possibly due to different composition of wastewater derived organic matter and the presence of scavengers, which may limit the oxidative efficiency of ozone. Copyright © 2016 Elsevier Ltd. All rights reserved.

Novel bioevaporation process for the zero-discharge treatment of highly concentrated organic wastewater.

PubMed

Yang, Benqin; Zhang, Lei; Lee, Yongwoo; Jahng, Deokjin

2013-10-01

A novel process termed as bioevaporation was established to completely evaporate wastewater by metabolic heat released from the aerobic microbial degradation of the organic matters contained in the highly concentrated organic wastewater itself. By adding the glucose solution and ground food waste (FW) into the biodried sludge bed, the activity of the microorganisms in the biodried sludge was stimulated and the water in the glucose solution and FW was evaporated. As the biodegradable volatile solids (BVS) concentration in wastewater increased, more heat was produced and the water removal ratio increased. When the volatile solids (VS) concentrations of both glucose and ground FW were 120 g L(-1), 101.7% and 104.3% of the added water was removed, respectively, by completely consuming the glucose and FW BVS. Therefore, the complete removal of water and biodegradable organic contents was achieved simultaneously in the bioevaporation process, which accomplished zero-discharge treatment of highly concentrated organic wastewater. Copyright © 2013 Elsevier Ltd. All rights reserved.

Molecular-Level Transformations of Lignin During Photo-Oxidation and Biodegradation

NASA Astrophysics Data System (ADS)

Feng, X.; Hills, K.; Simpson, A. J.; Simpson, M. J.

2009-05-01

As the second most abundant component of terrestrial plant residues, lignin plays a key role in regulating plant litter decomposition, humic substance formation, and dissolved organic matter (OM) production from terrestrial sources. Biodegradation is the primary decomposition process of lignin on land. However, photo- oxidation of lignin-derived compounds has been reported in aquatic systems and is considered to play a vital role in arid and semiarid regions. With increasing ultraviolet (UV) radiation due to ozone depletion, it is important to understand the biogeochemical fate of lignin exposed to photo-oxidation in terrestrial environments. This study examines and compares the transformation of lignin in a three-month laboratory simulation of biodegradation and photo-oxidation using molecular-level techniques. Lignin-derived monomers extracted by copper oxidation were analyzed by gas chromatography/mass spectrometry (GC/MS) from the water-soluble and insoluble OM of 13C-labeled corn leaves. Biodegradation increased the solubility of lignin monomers in comparison to the control samples, and the acid-to-aldehyde (Ad/Al) ratios increased in both the water-soluble and insoluble OM, indicating a higher degree of side-chain lignin oxidation. Photo-oxidation did not produce a significant change on the solubility or Ad/Al ratios of lignin from corn leaves. However, the ratios of trans-to-cis isomers of both cinnamyl units (p-coumaric acid and ferulic acid) increased with photo-oxidation and decreased with biodegradation in the insoluble OM. We also investigated the role of photo-oxidation in lignin transformation in soils cropped with 13C-labeled corn. Interestingly, the organic carbon content increased significantly with time in the water-soluble OM from soil/corn residues under UV radiation. An increase in the concentration of lignin monomers and dimers and the Ad/Al ratios was also observed with photo-oxidation. Iso-branched fatty acids of microbial origin remained in a similar concentration in the water-soluble OM from the UV-radiated and control soils, indicating little microbial contribution to the observed increase in water-soluble carbon. These observations suggest that photo-oxidation may increase the solubility of soil organic matter (SOM) through the oxidation of lignin-derived compounds. Mechanisms of lignin oxidation (demethylation or side-chain oxidation) and molecular size distribution changes of the water-soluble and NaOH-soluble OM during photo-oxidation and biodegradation will also be examined using solution-state nuclear magnetic resonance (NMR) spectroscopy. Collectively, our experiment demonstrates that while biodegradation predominates in the decomposition of lignin in plant litter, photo- oxidation may play an important part in destabilizing lignin-derived compounds in the soil.

Molecular-level transformations of lignin during photo-oxidation and biodegradation

NASA Astrophysics Data System (ADS)

Feng, X.; Hills, K.; Simpson, A. J.; Simpson, M. J.

2009-04-01

As the second most abundant component of terrestrial plant residues, lignin plays a key role in regulating plant litter decomposition, humic substance formation, and dissolved organic matter (OM) production from terrestrial sources. Biodegradation is the primary decomposition process of lignin on land. However, photo-oxidation of lignin-derived compounds has been reported in aquatic systems and is considered to play a vital role in arid and semiarid regions. With increasing ultraviolet (UV) radiation due to ozone depletion, it is important to understand the biogeochemical fate of lignin exposed to photo-oxidation in terrestrial environments. This study examines and compares the transformation of lignin in a three-month laboratory simulation of biodegradation and photo-oxidation using molecular-level techniques. Lignin-derived monomers extracted by copper oxidation were analyzed by gas chromatography/mass spectrometry (GC/MS) from the water-soluble and insoluble OM of 13C-labeled corn leaves. Biodegradation increased the solubility of lignin monomers in comparison to the control samples, and the acid-to-aldehyde (Ad/Al) ratios increased in both the water-soluble and insoluble OM, indicating a higher degree of side-chain lignin oxidation. Photo-oxidation did not produce a significant change on the solubility or Ad/Al ratios of lignin from corn leaves. However, the ratios of trans-to-cis isomers of both cinnamyl units (p-coumaric acid and ferulic acid) increased with photo-oxidation and decreased with biodegradation in the insoluble OM. We also investigated the role of photo-oxidation in lignin transformation in soils cropped with 13C-labeled corn. Interestingly, the organic carbon content increased significantly with time in the water-soluble OM from soil/corn residues under UV radiation. An increase in the concentration of lignin monomers and dimers and the Ad/Al ratios was also observed with photo-oxidation. Iso-branched fatty acids of microbial origin remained in a similar concentration in the water-soluble OM from the UV-radiated and control soils, indicating little microbial contribution to the observed increase in water-soluble carbon. These observations suggest that photo-oxidation may increase the solubility of soil organic matter (SOM) through the oxidation of lignin-derived compounds. Mechanisms of lignin oxidation (demethylation or side-chain oxidation) and molecular size distribution changes of the water-soluble and NaOH-soluble OM during photo-oxidation and biodegradation will also be examined using solution-state nuclear magnetic resonance (NMR) spectroscopy. Collectively, our experiment demonstrates that while biodegradation predominates in the decomposition of lignin in plant litter, photo-oxidation may play an important part in destabilizing lignin-derived compounds in the soil.

Evolution of biodegradation of deinking by-products used as alternative cover material.

PubMed

Aït-Benichou, Samah; Rodrigues Cabral, Alexandre; Teixeira Panarotto, Claudia

2008-01-01

Deinking by-products (DBP) have been used as alternative cover material for landfills and mine tailings. Since DBP is biodegradable because of its high cellulose and hemicellulose content, a laboratory experimental program was performed to monitor the evolution of biodegradation and changes in the physico-chemical and geotechnical properties of DBP samples submitted to accelerated biodegradation for 1460 days at 38 degrees C. The evolution of gas and leachate production was monitored in terms of both quality and quantity, which allowed for the calculation of mass loss with time. Under the conditions of the tests (no load applied), 19.6% of the mass was lost as gas, whereas 6.1% was leached out. The results show that biodegradation did not significantly alter the compaction behavior of DBP. The void ratio and water content increased significantly, while the volume of the samples slightly decreased. This seem to indicate that the porous structure of the samples was no longer the same after 1460 d of accelerated biodegradation. A slight increase in the relative density indicates that the organic/inorganic matter ratio increased. The results of permeability tests performed with samples at various stages of biodegradation and at various confining stresses show that the saturated hydraulic conductivity of recompacted biodegraded DBP decreased from 7 x 10(-7)cm/s to approximately 2 x 10(-7)cm/s, as biodegradation advanced.

Flammulina velutipes treatment of non-sterile tall wheat grass for enhancing biodegradability and methane production.

PubMed

Kasprzycka, Agnieszka; Lalak-Kańczugowska, Justyna; Tys, Jerzy

2018-05-09

In this study fungal pretreatment of non-sterile tall wheat grass via the white rot fungi Flammulina velutipes was studied and the effect on biodegradability of lignocellulosic biomass and methane production, was evaluated. Degradation of lignin, cellulose, hemicellulose, and dry matter in non-sterile tall wheat grass during 28 days of fungal pretreatment using different inoculum ratio (0%-50%) and moisture content (MC) (45% MC, 65% MC, and 75% MC) were assessed via comparison to untreated biomass. Pretreatment with F. velutipes was most effective at 65% MC and 40% inoculum ratio, resulting in 22% lignin removal. The corresponding methane yields were 181.3 Ndm 3 ·kg VS -1 , which were 280% higher than for the untreated tall wheat grass. Copyright © 2018 Elsevier Ltd. All rights reserved.

Molecular weight distribution of organic matter by ozonation and biofiltration.

PubMed

Lin, Yen-Hui

2012-01-01

Molecular weight (MW) distribution of organic matter by ozonation and biofiltration was evaluated using gel chromatography. The MW distribution of organic matter by Sephadex G-25 was observed from groups 2 (MW = 1,029-7,031 g/mol) and 3 (MW = 303-1,029 g/mol) shifted to groups 2, 3 and 4 (MW < 303 g/mol) under ozone doses of 0.1 and 0.4 mg O₃/mg total organic carbon (TOC). The shift in MW increases as ozone dosage increases. Biofiltration effectively degraded the organic molecule of group 2; however, the biofiltration only slightly degraded the organic molecule of group 4. Increased ozone dose destroyed functional groups C═C in phenolic and C-O in alcoholic compounds and increased UV-insensitive biodegradable organic carbon for subsequent biofiltration. Biofiltration effectively degraded organic compounds of alcohols and alkenes at an ozone dose of 0.1 mg O₃/mg TOC. Experimental approaches in this study can be applied to evaluate and diagnose the function of a full-scale process combining ozonation and biofiltration in drinking water treatment plants.

Recuperation de la matiere organique biodegradable presente dans l'effluent d'un MBBR a forte charge

NASA Astrophysics Data System (ADS)

Brosseau, Catherine

High-rate processes are receiving great interest due to their potential to favor the energy balance of water resource recovery facilities (WRRFs) either for their design or retrofit. Anaerobic digestion is a process that allows the valorization of organic biodegradable matter contained in sludge into biogas. This process also produces a stabilized sludge named digestate or biosolids that can be reused for agriculture purposes. This project proposed a secondary treatment train composed of a high-rate moving bed biofilm reactor (HR-MBBR) to biotransform colloidal and soluble biodegradable organics into particulate matter followed by an enhanced and compact physico-chemical separation process to recover mainly particulate organics and a part of the colloidal matter. A high-rate biological process operated at a low hydraulic retention time aimed at transforming colloidal and soluble fractions of organic matter into a particulate fraction for recovery by downstream separation process. The HR-MBBR effluent solids are known for their poor settleability, therefore requiring an efficient separation process downstream to ensure their recovery and to meet the effluent discharge regulations. The global objective of this project was to maximize the recovery of organic biodegradable matter for valorization into biogas by anaerobic digestion with an innovative treatment train combining an HR-MBBR and a separation process. The specific objectives of this report were 1) to characterize the HR-MBBR effluent solids and 2) to determine the efficiency of several physico-chemical separation processes combined with unbiodegradable or natural based coagulants and polymers. Effluents of lab-scale HR-MBBR fed with a synthetic soluble or domestic wastewater influent and the effluent of a full-scale HR-MBBR were used to evaluate the efficiency of separation processes adapted at bench-scale in jar-tests experiments. The processes studied were conventionnal settling, ballasted flocculation, dissolved air flotation and an innovative enhanced flotation process. Unlike conventional settling and dissolved air flotation, ballasted flocculation and enhanced flotation use a ballasted or flotation agent to accelerate the sludge settling or flotation rate. The original scientific hypothesis of this project is that the combination of enhanced flotation and natural based chemicals can meet a target total suspended solids (TSS) concentration of less or equal to 10 mg TSS/L in the clarified effluent of an HR-MBBR. The separation processes efficiencies were evaluated based on their TSS recoveries. Monitoring the chemical oxygen demand (COD) fractions allowed to better understand the underlying mechanisms of organic matter biotransformation and capture throughout the proposed treatment train. The concentration of solids expressed in TSS concentration in the MBBR effluent with a synthetic soluble influent was kept very low, from 27 to 61 mg TSS/L, which is about 2 to 9 times less than the expected concentration for an MBBR fed with domestic wastewater. Without the presence of particulate matter in the influent, the particulate matter in the MBBR effluent represented only the production of biomass detached by the shearing forces between the carriers. The TSS concentration and the efficiency of colloidal and soluble matter biotransformation into particulate matter increased with the MBBR hydraulic retention time. Wide volumetric particle size distributions ranging from 5 to 1000 mum in the lab-scale MBBR effluent were observed with a higher proportion of particles larger than 100 mum for a synthetic feed, and a higher proportion of small size particles of 30 mum for a domestic wastewater feed. The presence of lots of small size particles was attributed to unsettleable solids in the influent unchanged in the reactor. Despite the high proportion of large size particles for the MBBR with a synthetic feed, poor settleability of effluent solids was observed as static settling could only achieve TSS recoveries between 35 to 78%. Hence, coagulating agents were necessary to enhance the solids recovery. The combination of the innovative enhanced flotation process and unbiodegradable chemicals allowed to achieve TSS recovery efficiencies up to 97%. The enhanced flotation efficiency was reduced when using natural based chemicals, especially the natural based polymer which was not suited to treat waters with such high TSS concentrations. The hypothesis of the residual TSS concentration of 10 mg TSS/L was verified for half of the HR-MBBR operating conditions and the recovery efficiency did not seem to be influenced by the reactor hydraulic retention time, organic loading rate and temperature. More experiments are needed to confirm the effect of these parameters on TSS recovery efficiency. Although natural based chemicals reduced the coagulation and flocculation efficiency, they allowed a decrease in sludge production, which can represent a significant cost benefit. These chemicals resulted in an increase of 33 to 60% of the total COD of the MBBR effluent, compared to the unbiodegradable chemicals which only contributed about 2%. Natural based chemicals are recommended over unbiodegradable ones to promote the use of high biodegradability potential chemicals and to reduce the production of chemical sludge. However, to offset the increase of total COD, it may be required to add a treatment downstream to meet target secondary treatment COD concentration. Conventionnal settling and ballasted flocculation offered similar TSS recovery efficiencies to enhanced flottation (88% TSS recovery efficiency). The efficiency was reduced by 34% when using the dissolved air flotation process, much lower than the ones expected for such a separation process. The efficiency reduction was attributed to non-optimized and unadapted flotation lab-scale setups to treat medium strength wastewater. A similar innovative treatment train is currently being tested at pilot-scale in order to evaluate its carbon footprint and its potential to be eventually transposed to full-scale. Furthermore, the biodegradability and the biochemical methane production of the natural based chemicals are being determined. This project allowed to determine the potential of the innovative enhanced flotation process to recover the HR-MBBR solids when combined with natural based chemicals which are currently not often used in wastewater treatment for resource recovery.

Aerobic co-treatment of landfill leachate and domestic wastewater - are slowly biodegradable organics removed or simply diluted?

PubMed

Campos, R; Ferraz, F M; Vieira, E M; Povinelli, J

2014-01-01

This study investigated the co-treatment of landfill leachate/domestic wastewater in bench-scale activated sludge (AS) reactors to determine whether the slowly biodegradable organic matter (SBOM) was removed rather than diluted. The AS reactors were loaded with mixtures of raw leachate and leachate that was pretreated by air stripping. The tested volumetric ratios were 0%, 0.2%, 2% and 5%. For all of the tested conditions, the reactors performed better when pretreated leachate was used rather than raw leachate, and the best volumetric ratio was 2%. The following removals were obtained: 97% for the biochemical oxygen demand (BOD5,20), 79% for total suspended solids, 77% for dissolved organic carbon and 84% for soluble chemical oxygen demand. Most of the pretreated leachate SBOM (65%) was removed rather than diluted or adsorbed into the sludge, as confirmed by Fourier transform infrared (FTIR) spectroscopy analyses.

Biodegradation of 1,2,3- and 1,2,4-Trichlorobenzene in Soil and in Liquid Enrichment Culture †

PubMed Central

Marinucci, A. C.; Bartha, R.

1979-01-01

The biodegradation of radiochemically pure (99%) 1,2,3- and 1,2,4-trichlorobenzene (TCB) in soil was investigated. Experimental difficulties posed by the high volatility and slow biodegradation rate of the TCBs were partially overcome by using a specially designed incubation and trapping apparatus. Evolution of 14CO2 from active versus poisoned soil dosed with 50 μg of the individual TCBs per g gave conclusive proof that both isomers are biodegradable. At 20°C, 1,2,4-TCB was mineralized at an approximate rate of 1 nmol/day per 20 g of soil sample, and 1,2,3-TCB was mineralized at one-half to one-third that rate. Mineral fertilizers or cosubstrates failed to increase TCB mineralization rates in soil. Anaerobic conditions had a negative effect on mineralization, and increased temperatures had a positive effect. With increasing 1,2,4-TCB concentrations, 14CO2 evolution exhibited saturation kinetics with an apparent Km of 55.5 nmol per g of soil. Recovery of total radioactivity was good from soil containing high organic matter concentrations. From low-organic-matter soil, some of the radioactivity was recovered only on combustion, and overall recovery was lower. In soil-inoculated liquid culture, the cosubstrates glucose and benzene caused a slight stimulation of 1,2,4-TCB mineralization. Cochromatography of known standards with the extracts of soil pretreated with [14C]TCBs indicated that 3,4,5-trichlorophenol, 2,6-dichlorophenol and, to a lesser degree, 2,3-dichlorophenol were present in soils incubated with 1,2,3-TCB. 2,4-, 2,5-, and 3,4-dichlorophenol were present in soils incubated with 1,2,4-TCB. PMID:120698

Character and chlorine reactivity of dissolved organic matter from a mountain pine beetle impacted watershed.

PubMed

Beggs, Katherine M H; Summers, R Scott

2011-07-01

Lodgepole pine needle leachates from trees killed by the mountain pine beetle epidemic in Colorado were evaluated for dissolved organic matter (DOM) character, biodegradation, treatability by coagulation and disinfection byproduct (DBP) formation. An average of 8.0 (±0.62) mg-DOC/g-dry weight of litter was leached from three sets of needle samples representing different levels of forest floor degradation. Fluorescence analysis included collection of excitation and emission matrices, examination of peak intensities and development of a 4-component parallel factor (PARAFAC) analysis model. Peak intensity and PARAFAC analyses provided complementary results showing that fresh leachates were initially dominated by polyphenolic/protein-like components (60-70%) and humic-like fluorescence increased (40-70%) after biodegradation. Humic-like components were removed by coagulation (20-64%), while polyphenolic/protein-like components were not, which may create challenges for utilities required to meet OM removal regulations. DBP formation yields after 24 h chlorination were 20.5-26.4 μg/mg-DOC for trihalomethanes and 9.0-14.5 μg/mg-DOC for haloacetic acids for fresh leachates; increased after biodegradation to 19.2-64.2 and 7.1-30.9 μg/mg-DOC, respectively; and decreased after coagulation (fresh: 11.3-17.7;5.7-7.6 μg/mg-DOC, respectively; biodegraded: 12.0-27.3 and 2.9-7.2 μg/mg-DOC, respectively), reflective of changes in concentration of humic material. Humic-like PARAFAC components and peak intensities were positively correlated (R(2) ≥ 0.45) to DBP concentrations, while polyphenolic/protein-like components were not (R(2) ≤ 0.17).

Dissolved organic matter and estrogen interactions regulate estrogen removal in the aqueous environment: A review.

PubMed

Ma, Li; Yates, Scott R

2018-06-03

This review summarizes the characterization and quantification of interactions between dissolved organic matter (DOM) and estrogens as well as the effects of DOM on aquatic estrogen removal. DOM interacts with estrogens via binding or sorption mechanisms like π-π interaction and hydrogen bonding. The binding affinity is evaluated in terms of organic-carbon-normalized sorption coefficient (Log K OC ) which varies with types and composition of DOM. DOM has been suggested to be a more efficient sorbent compared with other matrices, such as suspended particulate matter, sediment and soil; likely associated with its large surface area and concentrated carbon content. As a photosensitizer, DOM enhanced estrogen photodegradation when the concentration of DOM was below a threshold value, and when above, the acceleration effect was not observed. DOM played a dual role in affecting biodegradation of estrogens depending on the recalcitrance of the DOM and the nutrition status of the degraders. DOM also acted as an electron shuttle (redox mediator) mediating the degradation of estrogens. DOM hindered enzyme-catalyzed removal of estrogens while enhanced their transformation during the simultaneous photo-enzymatic process. Membrane rejection of estrogens was pronounced for hydrophobic DOM with high aromaticity and phenolic moiety content. Elimination of estrogens via photolysis, biodegradation, enzymolysis and membrane rejection in the presence of DOM is initiated by sorption, accentuating the role of DOM as a mediator in regulating aquatic estrogen removal. Published by Elsevier B.V.

Organic Matter Composition, Recycling Susceptibility, and the Effectiveness of the Biological Pump – An Evaluation Using NMR Spectra of Marine Plankton

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

Paytan, Adina

Carbon (C) sequestration through fertilization of phytoplankton with micronutrients and enhancement of the absorption and retention of atmospheric C by ocean biota heavily depends on the efficiency of the “biological pump”. The long-term effectiveness of this strategy depends on a net transfer of C from the upper ocean-atmosphere system to the deep ocean where the C is removed from contact with the atmosphere for an extended period of time. This C removal can be equated to the amount of C fixation by phytoplankton minus the C cycling and regeneration in the euphotic zone. If the regeneration efficiency is increased, thenmore » despite increased C fixation, no net loss (sequestration) of C will result. A reduction in cycling efficiency in the euphotic zone, on the other hand, will increase the effectiveness of the “biological pump” and thus C sequestration. The degree of organic matter biodegradation and recycling depends on the “reactivity” of compounds synthesized by the biota, which in turn, is controlled by the structural characteristic of these compounds. There is considerable evidence that different phytoplankton taxa differ substantially in their biogeochemical characteristics and it is likely that the relative abundance of different compounds synthesized by these distinct taxa, and even within each group at different growth conditions, will differ too. This variability in biosynthesis and thus abundance of a wide range of organic compounds in the water column would lend itself to different susceptibility for biodegradation and regeneration. Knowledge of the distribution of various organic matter structural groups synthesized by distinct taxa, the dependence of the organic matter compound classes on different growth conditions (temperature, light, nutrients) and the selective susceptibility of these compound to regeneration is crucial for estimating the potential for rapid regeneration in the euphotic zone, and thus the effectiveness of the “biological pump”.« less

Natural biopolimers in organic food packaging

NASA Astrophysics Data System (ADS)

Wieczynska, Justyna; Cavoski, Ivana; Chami, Ziad Al; Mondelli, Donato; Di Donato, Paola; Di Terlizzi, Biagio

2014-05-01

Concerns on environmental and waste problems caused by use of non-biodegradable and non-renewable based plastic packaging have caused an increase interest in developing biodegradable packaging using renewable natural biopolymers. Recently, different types of biopolymers like starch, cellulose, chitosan, casein, whey protein, collagen, egg white, soybean protein, corn zein, gelatin and wheat gluten have attracted considerable attention as potential food packaging materials. Recyclable or biodegradable packaging material in organic processing standards is preferable where possible but specific principles of packaging are not precisely defined and standards have to be assessed. There is evidence that consumers of organic products have specific expectations not only with respect to quality characteristics of processed food but also in social and environmental aspects of food production. Growing consumer sophistication is leading to a proliferation in food eco-label like carbon footprint. Biopolymers based packaging for organic products can help to create a green industry. Moreover, biopolymers can be appropriate materials for the development of an active surfaces designed to deliver incorporated natural antimicrobials into environment surrounding packaged food. Active packaging is an innovative mode of packaging in which the product and the environment interact to prolong shelf life or enhance safety or sensory properties, while maintaining the quality of the product. The work will discuss the various techniques that have been used for development of an active antimicrobial biodegradable packaging materials focusing on a recent findings in research studies. With the current focus on exploring a new generation of biopolymer-based food packaging materials with possible applications in organic food packaging. Keywords: organic food, active packaging, biopolymers , green technology

Sorptive fractionation of organic matter and formation of organo-hydroxy-aluminum complexes during litter biodegradation in the presence of gibbsite

NASA Astrophysics Data System (ADS)

Heckman, K.; Grandy, A. S.; Gao, X.; Keiluweit, M.; Wickings, K.; Carpenter, K.; Chorover, J.; Rasmussen, C.

2013-11-01

Solid and aqueous phase Al species are recognized to affect organic matter (OM) stabilization in forest soils. However, little is known about the dynamics of formation, composition and dissolution of organo-Al hydroxide complexes in microbially-active soil systems, where plant litter is subject to microbial decomposition in close proximity to mineral weathering reactions. We incubated gibbsite-quartz mineral mixtures in the presence of forest floor material inoculated with a native microbial consortium for periods of 5, 60 and 154 days. At each time step, samples were density separated into light (<1.6 g cm-3), intermediate (1.6-2.0 g cm-3), and heavy (>2.0 g cm-3) fractions. The light fraction was mainly comprised of particulate organic matter, while the intermediate and heavy density fractions contained moderate and large amounts of Al-minerals, respectively. Multi-method interrogation of the fractions indicated the intermediate and heavy fractions differed both in mineral structure and organic compound composition. X-ray diffraction analysis and SEM/EDS of the mineral component of the intermediate fractions indicated some alteration of the original gibbsite structure into less crystalline Al hydroxide and possibly proto-imogolite species, whereas alteration of the gibbsite structure was not evident in the heavy fraction. DRIFT, Py-GC/MS and STXM/NEXAFS results all showed that intermediate fractions were composed mostly of lignin-derived compounds, phenolics, and polysaccharides. Heavy fraction organics were dominated by polysaccharides, and were enriched in proteins, N-bearing compounds, and lipids. The source of organics appeared to differ between the intermediate and heavy fractions. Heavy fractions were enriched in 13C with lower C/N ratios relative to intermediate fractions, suggesting a microbial origin. The observed differential fractionation of organics among hydroxy-Al mineral types suggests that microbial activity superimposed with abiotic mineral-surface-mediated fractionation leads to strong density differentiation of organo-mineral complex composition even over the short time scales probed in these incubation experiments. The data highlight the strong interdependency of mineral transformation, microbial community activity, and organic matter stabilization during biodegradation.

Mobilization of hydrophobic contaminants from soils by enzymatic depolymerization of soil organic matter.

PubMed

Wicke, Daniel; Reemtsma, Thorsten

2010-02-01

The effect of hydrolytic exoenzymes on the release of hydrophobic organic contaminants (HOC) from two different surface soils was studied in laboratory batch experiments. Incubation of the soils with cellulase with an activity fivefold above the inherent soil activity enhanced the release of hydrophobic contaminants (polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCB) and hydroxylated PCB) by 40-200%. Xylanase and invertase did not show measurable effects at comparable relative activity levels. This suggests that cellulose substructures are important for the retention of HOC in soil organic matter (SOM). Hydrolytic exoenzymes, and the microorganisms that release them, contribute to the mobilization of HOC from soil, by shifting the sorption equilibrium in the course of SOM transformation into dissolved organic matter or by facilitating HOC diffusion as a consequence of reduced rigidity of SOM. We conclude that not only biodegradation but also sorption and desorption of HOC in soil can be influenced by (micro-) biology and the factors that determine its activity.

Classification and modelling of non-extractable residue (NER) formation from xenobiotics in soil - a synthesis

NASA Astrophysics Data System (ADS)

Kaestner, Matthias; Nowak, Karolina; Miltner, Anja; Trapp, Stefan; Schaeffer, Andreas

2014-05-01

This presentation provides a comprehensive overview about the formation of non-extractable residues (NER) from organic pesticides and contaminants in soil and tries classifying the different types. Anthropogenic organic chemicals are deliberately (e.g. pesticides) or unintentionally (e.g. polyaromatic hydrocarbons [PAH], chlorinated solvents, pharmaceuticals) released in major amounts to nearly all compartments of the environment. Soils and sediments as complex matrices provide a wide variety of binding sites and are the major sinks for these compounds. Many of the xenobiotics entering soil undergo turnover processes and can be volatilised, leached to the groundwater, degraded by microorganisms or taken up and enriched by living organisms. Xenobiotic NER may be derived from parent compounds and primary metabolites that are sequestered (sorbed or entrapped) within the soil organic matter (type I NER) or can be covalently bound (type II NER). Especially type I NER may pose a considerably environmental risk of potential release. However, NER resulting from productive biodegradation, which means the conversion of carbon (or nitrogen) from the compounds into microbial biomass molecules during microbial degradation (type III, bioNER), do not pose any risk. Experimental and analytical approaches to clearly distinguish between the types are provided and a model to prospectively estimate their fate in soil is proposed.

Toxicity assessment of chlorpyrifos-degrading fungal bio-composites and their environmental risks.

PubMed

Liu, Jie; Zhang, Xiaoying; Yang, Mengran; Hu, Meiying; Zhong, Guohua

2018-02-01

Bioremediation techniques coupling with functional microorganisms have emerged as the most promising approaches for in-situ elimination of pesticide residue. However, the environmental safety of bio-products based on microorganisms or engineered enzymes was rarely known. Here, we described the toxicity assessment of two previously fabricated fungal bio-composites which were used for the biodegradation of chlorpyrifos, to clarify their potential risks on the environment and non-target organisms. Firstly, the acute and chronic toxicity of prepared bio-composites were evaluated using mice and rabbits, indicating neither acute nor chronic effect was induced via short-term or continuous exposure. Then, the acute mortality on zebrafish was investigated, which implied the application of fungal bio-composites had no lethal risk on aquatic organisms. Meanwhile, the assessment on soil organic matters suggested that no threat was posed to soil quality. Finally, by monitoring, the germination of cabbage was not affected by the exposure to two bio-products. Therefore, the application of fungal bio-composites for chlorpyrifos elimination cannot induce toxic risk to the environment and non-target organisms, which insured the safety of these engineered bio-products for realistic management of pesticide residue, and provided new insights for further development of bioremediation techniques based on functional microorganisms.

Comparison of biological activated carbon (BAC) and membrane bioreactor (MBR) for pollutants removal in drinking water treatment.

PubMed

Tian, J Y; Chen, Z L; Liang, H; Li, X; Wang, Z Z; Li, G B

2009-01-01

Biological activated carbon (BAC) and membrane bioreactor (MBR) were systematically compared for the drinking water treatment from slightly polluted raw water under the same hydraulic retention time (HRT) of 0.5 h. MBR exhibited excellent turbidity removal capacity due to the separation of the membrane; while only 60% of influent turbidity was intercepted by BAC. Perfect nitrification was achieved by MBR with the 89% reduction in ammonia; by contrast, BAC only eliminated a moderate amount of influent ammonia (by 54.5%). However, BAC was able to remove more dissolved organic matter (DOM, especially for organic molecules of 3,000 approximately 500 Daltons) and corresponding disinfection by-product formation potential (DBPFP) in raw water than MBR. Unfortunately, particulate organic matter (POM) was detected in the BAC effluent. On the other hand, BAC and MBR displayed essentially the same capacity for biodegradable organic matter (BOM) removal. Fractionation of DOM showed that the removal efficiencies of hydrophobic neutrals, hydrophobic acids, weakly hydrophobic acids and hydrophilic organic matter through BAC treatment were 11.7%, 8.8%, 13.9% and 4.8% higher than that through MBR; while MBR achieved 13.8% higher hydrophobic bases removal as compared with BAC.

[Study on the advanced pre-treatments of reclaimed water used for groundwater recharge].

PubMed

Gao, Yu-Tuan; Zhang, Xue; Zhao, Xuan; Zhao, Gang

2012-03-01

To prevent groundwater contamination, pretreatments of reclaimed water are needed before the groundwater recharge. In this study, five treatments, including ultrafiltration (UF), ozonation, magnetic ion exchange (MIEX), UF coupled with ozonation and MIEX coupled with ozonation, were evaluated for their purification efficiencies of the reclaimed water and their influences on the following soil aquifer treatments. For organic matters in the secondary effluents, identified as dissolved organic carbon (DOC) and specific ultraviolet absorbance (SUVA), 20% DOC and 10% SUVA are removed by MIEX treatment with dose of 5 mL x L(-1), while only 10% DOC and no SUVA are removed by UF, but neither of these two pretreatments enhance the purification of soil aquifer treatments. Differently, SUVA of the secondary effluents are removed by 60%-79% by ozonation alone or coupled with UF/MIEX, increasing the biodegradability of the reclaimed water. These pretreatments significantly enhance the removal of organic matters by the following soil aquifer with DOC in the final effluents reducing to 1-2 mg x L(-1). For nitrogen, MIEX can remove 25% NO3(-) -N, and ozonation can remove 72% NH4(+) -N. The soil aquifer treatment could efficiently remove NH4(+) -N to below 0.5 mg x L(-1), while no obvious removal is detected for NO3(-) -N. In conclusion, more attentions should be paid to the organic matters and NO3(-) -N during the pretreatments of reclaimed water. Among all the pretreatments tested here, ozonation coupled with MIEX is capable of increasing the biodegradability of the reclaimed water and removing NO3(-) -N, which is a good choice for the pretreatment of groundwater recharge.

Classes of organic molecules targeted by a methanogenic microbial consortium grown on sedimentary rocks of various maturities

PubMed Central

Meslé, Margaux; Dromart, Gilles; Haeseler, Frank; Oger, Philippe M.

2015-01-01

Organic-rich shales are populated by methanogenic consortia that are able to degrade the fossilized organic matter into methane gas. To identify the organic fraction effectively degraded, we have sequentially depleted two types of organic-rich sedimentary rocks, shale, and coal, at two different maturities, by successive solvent extractions to remove the most soluble fractions (maltenes and asphaltenes) and isolate kerogen. We show the ability of the consortia to produce methane from all rock samples, including those containing the most refractory organic matter, i.e., the kerogen. Shales yielded higher methane production than lignite and coal. Mature rocks yielded more methane than immature rocks. Surprisingly, the efficiency of the consortia was not influenced by the removal of the easily biodegradable fractions contained in the maltenes and asphaltenes. This suggests that one of the limitations of organic matter degradation in situ may be the accessibility to the carbon and energy source. Indeed, bitumen has a colloidal structure that may prevent the microbial consortia from reaching the asphaltenes in the bulk rock. Solvent extractions might favor the access to asphaltenes and kerogen by modifying the spatial organization of the molecules in the rock matrix. PMID:26136731

Use of Fenton reaction for the treatment of leachate from composting of different wastes.

PubMed

Trujillo, Daniel; Font, Xavier; Sánchez, Antoni

2006-11-02

The oxidation of leachate coming from the composting of two organic wastes (wastewater sludge and organic fraction of municipal solid wastes) using the Fenton's reagent was studied using different ratios [Fe(2+)]/[COD](0) and maintaining a ratio [H(2)O(2)]/[COD](0) equal to 1. The optimal conditions for Fenton reaction were found at a ratio [Fe(2+)]/[COD](0) equal to 0.1. Both leachates were significantly oxidized under these conditions in terms of COD removal (77 and 75% for leachate from wastewater sludge composting and leachate from organic fraction of municipal solid wastes, respectively) and BOD(5) removal (90 and 98% for leachate from wastewater sludge composting and leachate from organic fraction of municipal solid wastes, respectively). Fenton's reagent was found to oxidize preferably biodegradable organic matter of leachate. In consequence, a decrease in the biodegradability of leachates was observed after Fenton treatment for both leachates. Nevertheless, Fenton reaction proved to be a feasible technique for the oxidation of the leachate under study, and it can be considered a suitable treatment for this type of wastewaters.

Biodegradation of organic sulfur compounds in crude oils from Oman

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

Koopmans, M.P.; Sinninghe Damste, J.S.; Leeuw, J.W. de

1996-10-01

Five closely related crude oils from Oman, showing various degrees of biodegradation ranging from non-biodegraded to severely biodegraded, were quantitatively investigated for free and sulfur-bound hydrocarbons. Hydrocarbons sequestered in the alkylsulfide fraction and the polar fraction were analysed after Raney Ni desulfurisation and subsequent hydrogenation. With increasing degree of biodegradation, pristane (Pr), phytane (Ph) and a series of mid-chain methyl alkanes are enriched relative to the n-alkanes, as evidenced by increased Pr/n-C{sub 17} and Ph/n-C{sub 18} ratios. In the severely biodegraded oil no free n-alkanes, mid-chain alkanes or isoprenoid alkanes could be detected. Sterane and hopane distributions, however, remain unchangedmore » throughout the biodegradation series. Hydrocarbons sequestered in the alkylsulfide fraction (i.e. n-alkanes, mid-chain methyl alkanes, Pr and Ph) are biodegraded at lower rates than the corresponding hydrocarbons in the saturated hydrocarbon fraction. Similar hydrocarbons sequestered in the polar fraction are biodegraded at even lower rates. These results suggest that hydrocarbons bound by a higher amount of sulfur links are biodegraded at a lower rate.« less

Biodegradation of hexachlorocyclohexane (HCH) by microorganisms.

PubMed

Phillips, Theresa M; Seech, Alan G; Lee, Hung; Trevors, Jack T

2005-08-01

The organochlorine pesticide Lindane is the gamma-isomer of hexachlorocyclohexane (HCH). Technical grade Lindane contains a mixture of HCH isomers which include not only gamma-HCH, but also large amounts of predominantly alpha-, beta- and delta-HCH. The physical properties and persistence of each isomer differ because of the different chlorine atom orientations on each molecule (axial or equatorial). However, all four isomers are considered toxic and recalcitrant worldwide pollutants. Biodegradation of HCH has been studied in soil, slurry and culture media but very little information exists on in situ bioremediation of the different isomers including Lindane itself, at full scale. Several soil microorganisms capable of degrading, and utilizing HCH as a carbon source, have been reported. In selected bacterial strains, the genes encoding the enzymes involved in the initial degradation of Lindane have been cloned, sequenced, expressed and the gene products characterized. HCH is biodegradable under both oxic and anoxic conditions, although mineralization is generally observed only in oxic systems. As is found for most organic compounds, HCH degradation in soil occurs at moderate temperatures and at near neutral pH. HCH biodegradation in soil has been reported at both low and high (saturated) moisture contents. Soil texture and organic matter appear to influence degradation presumably by sorption mechanisms and impact on moisture retention, bacterial growth and pH. Most studies report on the biodegradation of relatively low (< 500 mg/kg) concentrations of HCH in soil. Information on the effects of inorganic nutrients, organic carbon sources or other soil amendments is scattered and inconclusive. More in-depth assessments of amendment effects and evaluation of bioremediation protocols, on a large scale, using soil with high HCH concentrations, are needed.

Method of increasing biodegradation of sparingly soluble vapors

DOEpatents

Cherry, Robert S.

2000-01-01

A method for increasing biodegradation of sparingly soluble volatile organic compounds (VOCs) in a bioreactor is disclosed. The method comprises dissolving in the aqueous phase of the bioreactor a water soluble, nontoxic, non-biodegradable polymer having a molecular weight of at least 500 and operable for decreasing the distribution coefficient of the VOCs. Polyoxyalkylene alkanols are preferred polymers. A method of increasing the growth rate of VOC-degrading microorganisms in the bioreactor and a method of increasing the solubility of sparingly soluble VOCs in aqueous solution are also disclosed.

Effect of aging of chemicals in soil on their biodegradability and extractability

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

Hatzinger, P.B.; Alexander, M.

1995-11-01

A study was conducted to determine whether the time that a compound remains in a soil affects its biodegradability and the ease of its extraction. Phenanthrene and 4-nitrophenol were aged in sterilized loam and muck, and bacteria able to degrade the compounds were then added to the soils. increasingly smaller amounts of phenanthrene in the muck and 4-nitrophenol in both soils were mineralized with increasing duration of aging. Aging also increased the resistance of phenanthrene to biodegradation in nutrient-amended aquifer sand. The rate of miner- alization of the two compounds in both soils declined with increasing periods of aging. Themore » amount of phenanthrene and 4-nitrophenol added to sterile soils that was recovered by butanol extraction declined with duration of aging, but subsequent Soxhlet extraction recovered phenanthrene from the loam but not the muck. The extents of mineralization of phenanthrene previously incubated for up to 27 days with soluble or insoluble organic matter from the muck were similar. Less aged than freshly added phenanthrene was biodegraded if aggregates in the muck were sonically disrupted. The data show that phenanthrene and 4-nitrophenol added to soil become increasingly more resistant with time to biodegradation and extraction.« less

Impact of solids retention time on dissolved organic nitrogen and its biodegradability in treated wastewater.

PubMed

Simsek, Halis; Kasi, Murthy; Ohm, Jae-Bom; Murthy, Sudhir; Khan, Eakalak

2016-04-01

Dissolved organic nitrogen (DON) and its biodegradability in treated wastewater have recently gained attention due to increased regulatory requirements on effluent quality to protect receiving waters. Laboratory scale chemostat experiments were conducted at 9 different solids retention times (SRTs) (0.3, 0.7, 2, 3, 4, 5, 7, 8, and 13 days) to examine whether SRT could be used to control DON, biodegradable DON (BDON), and DON biodegradability (BDON/DON) levels in treated wastewater. Results indicated no trend between effluent DON and SRTs. Effluent BDON was comparable for SRTs of 0.3-4 days and had a decreasing trend with SRT after that. Effluent DON biodegradability (effluent BDON/effluent DON) ranging from 23% to 59% tended to decrease with SRT. Chemostat during longer SRTs, however, was contributing to non-biodegradable DON (NBDON) and this fraction of DON increased with SRT above 4 days. Model calibration results indicated that ammonification rate, and growth rates for ordinary heterotrophs, ammonia oxidizing bacteria and nitrite oxidizing bacteria were not constants but have a decreasing trend with increasing SRT. This study indicates the benefit of high SRTs in term of producing effluent with less DON biodegradability leading to relatively less oxygen consumption and nutrient support in receiving waters. Copyright © 2016 Elsevier Ltd. All rights reserved.

Assessment of bioavailability limitations during slurry biodegradation of petroleum hydrocarbons in aged soils.

PubMed

Huesemann, Michael H; Hausmann, Tom S; Fortman, Tim J

2003-12-01

In an effort to determine whether bioavailability limitations are responsible for the slow or incomplete hydrocarbon biodegradation in aged soils, both the rate of desorption (rdes) and biodegradation (rbio) was measured for n-alkanes and polynuclear aromatic hydrocarbons (PAHs) at different times during the slurry biotreatment of six different soils. While all n-alkanes were biodegraded to various degrees depending on their respective carbon number and the soil organic matter content, none of them were desorbed to a significant extent, indicating that these saturated hydrocarbons do not need to be transferred from the soil particles into the aqueous phase in order to be metabolized by microorganisms. Most two- and three-ring PAHs biodegraded as fast as they were desorbed (rbio = rdes); that is, desorption rates controlled biodegradation rates. By contrast, the biodegradation kinetics of four-, five-, and six-ring PAHs was limited by microbial factors during the initial phase (rbio < rdes) while becoming mass-transfer rate limited during the final phase of bioremediation treatment (rbio = rdes). Whenever PAH biodegradation stalled or did not occur at all (rbio = 0), it was never due to bioavailability limitations (rdes > 0) but was more likely caused by microbial factors. such as the absence of specific PAH degraders or cometabolic substrates. Consequently, PAHs that are found to be microbially recalcitrant in aged soils may not be so because of limited bioavailability and thus could pose a greater risk to the environment than previously thought.

Assessment of Bioavailability Limitations During Slurry Biodegradation of Petroleum Hydrocarbons in Aged Soils

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

Huesemann, Michael H.; Hausmann, Tom S.; Fortman, Timothy J.

In an effort to determine whether bioavailability limitations are responsible for the slow or incomplete hydrocarbon biodegradation in aged soils, both the rate of desorption (rdes) and biodegradation (rbio) was measured for n-alkanes and polynuclear aromatic hydrocarbons (PAHs) at different times during the slurry biotreatment of six different soils. While all n-alkanes were biodegraded to various degrees depending on their respective carbon number and the soil organic matter content, none of them were desorbed to a significant extent indicating that these saturated hydrocarbons do not need to be transferred from the soil particles into the aqueous phase in order tomore » be metabolized by microorganisms. Most 2 and 3 ring PAHs biodegraded as fast as they were desorbed (rbio=rdes), i.e., desorption rates controlled biodegradation rates. By contrast, the biodegradation kinetics of 4, 5, and 6 ring PAHs was limited by microbial factors during the initial phase (rbio < rdes) while becoming mass-transfer rate limited during the final phase of bioremediation treatment (rbio=rdes). Whenever PAH biodegradation stalled or did not occur at all (rbio=0), it was never due to bioavailability limitations (rdes >> 0) but was more likely caused by microbial factors such as the absence of specific PAH degraders or cometabolic substrates. Consequently, PAHs that are found to be microbially recalcitrant in aged soils may not be so because of limited bioavailability and thus could pose a greater risk to the environment than previously thought.« less

Fluorescence evolution of leachates during treatment processes from two contrasting landfills.

PubMed

Sun, W L; Liu, T T; Cui, F; Ni, J R

2008-10-01

Landfill leachates are composed of a complex mixture of organic matter, including a wide range of potentially fluorescent organic compounds. The fluorescence excitation-emission matrix (FEEM) of leachates during treatment processes is investigated. Particular attention is paid to the fluorescence evolution of leachates during treatment processes. Two typical types of landfill, landfill A (a direct municipal solid waste (MSW) landfill) and landfill B (disposal of bottom ashes from MSW incinerators), in a city in Southern China were selected. The results show that two characteristic and intense excitation-emission peaks located at Ex/Em = 310-330 nm/395-410 nm (peak alpha) and Ex/Em = 250-260 nm/450-460 nm (peak alpha') are observed. As the aromatic chemicals, capable of emitting fluorescence, are more recalcitrant to biodegradation than aliphatic chemicals, enhancement of the dissolved organic carbon normalized fluorescence intensities is demonstrated during treatment processes of leachate A and leachate B. This is confirmed by the variation of ultraviolet absorptivity of leachates at 254 nm. Peak alpha' and peak alpha are attributed to a mixture of xenobiotic organic compounds with low molecular weight and relatively stable aromatic fulvic-like matters with high molecular weight, respectively. Humic substances are more resistant to biodegradation than xenobiotic organic compounds, so a significant reduction in the Ialpha'/Ialpha values (fluorescence intensity ratios of peak alpha' and peak a) of leachate A was observed during treatment processes. However, no evident variation for the Ialpha/Ialpha values of leachate B was found during treatment processes owing to the low concentrations of xenobiotic organic compounds in leachate B after incineration.

Composting of a solid olive-mill by-product ("alperujo") and the potential of the resulting compost for cultivating pepper under commercial conditions.

PubMed

Alburquerque, J A; Gonzálvez, J; García, D; Cegarra, J

2006-01-01

A pollutant solid material called "alperujo" (AL), which is the main by-product from the Spanish olive oil industry, was composted with a cotton waste as bulking agent, and the compost obtained (ALC) was compared with a cattle manure (CM) and a sewage sludge compost (SSC) for use as organic amendment on a calcareous soil. The experiment was conducted with a commercial pepper crop in a greenhouse using fertigation. Composting AL involved a relatively low level of organic matter biodegradation, an increase in pH and clear decreases in the C/N and the fat, water-soluble organic carbon and phenol contents. The resulting compost, which was rich in organic matter and free of phytotoxicity, had a high potassium and organic nitrogen content but was low in phosphorus and micronutrients. The marketable yields of pepper obtained with all three organic amendments were similar, thus confirming the composting performance of the raw AL. When CM and SSC were used for soil amendment, the soil organic matter content was significantly reduced after cultivation, while it remained almost unchanged in the ALC-amended plots.

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.

Application of micronucleus test and comet assay to evaluate BTEX biodegradation.

PubMed

Mazzeo, Dânia Elisa Christofoletti; Matsumoto, Silvia Tamie; Levy, Carlos Emílio; de Angelis, Dejanira de Franceschi; Marin-Morales, Maria Aparecida

2013-01-01

The BTEX (benzene, toluene, ethylbenzene and xylene) mixture is an environmental pollutant that has a high potential to contaminate water resources, especially groundwater. The bioremediation process by microorganisms has often been used as a tool for removing BTEX from contaminated sites. The application of biological assays is useful in evaluating the efficiency of bioremediation processes, besides identifying the toxicity of the original contaminants. It also allows identifying the effects of possible metabolites formed during the biodegradation process on test organisms. In this study, we evaluated the genotoxic and mutagenic potential of five different BTEX concentrations in rat hepatoma tissue culture (HTC) cells, using comet and micronucleus assays, before and after biodegradation. A mutagenic effect was observed for the highest concentration tested and for its respective non-biodegraded concentration. Genotoxicity was significant for all non-biodegraded concentrations and not significant for the biodegraded ones. According to our results, we can state that BTEX is mutagenic at concentrations close to its water solubility, and genotoxic even at lower concentrations, differing from some described results reported for the mixture components, when tested individually. Our results suggest a synergistic effect for the mixture and that the biodegradation process is a safe and efficient methodology to be applied at BTEX-contaminated sites. Copyright © 2012 Elsevier Ltd. All rights reserved.

Enhancement of surfactant biodegradation with an anaerobic membrane bioreactor by introducing microaeration.

PubMed

Cheng, Zhenmin; Wei, Yuansong; Zhang, Qingqing; Zhang, Junya; Lu, Tiedong; Pei, Yuanmei

2018-06-01

In controlled ecological life support system (CELSS), 100% water recycle efficiency is needed. Both water and nutrients in wastewater needs reclaiming. In an anaerobic membrane bioreactor (AnMBR) designed to hydrolyze organic matters and convert organic nitrogen, accumulation of anionic surfactants and organic compounds was observed in the supernatant. To solve the problem, microaeration which had rarely been reported to enhance surfactants biodegradation in anaerobic process was introduced and it was proved to be an effective approach that resulted in concentrations of surfactants and soluble chemical oxygen demand (SCOD) in the supernatant decreasing from 9000 mg/L and 40000 mg/L to 2000 mg/L and 10000 mg/L, respectively. And the degradations followed the kinetic characteristics of zero order reaction with R 2 values of 0.9472 and 0.949. Three-dimensional excitation emission matrix (3D-EEM) analysis revealed that some activities of microbes were activated and enhanced by microaeration, which resulted in the disintegration of aggregates of large molecules, indicated by the size exclusion chromatography (SEC). After the introduction of microaeration, the emerging genera Aquamicrobium, Flaviflexus, Pseudomonas and Thiopseudomonas in the microbial community might be responsible for the effective biodegradation of the surfactants. Copyright © 2018 Elsevier Ltd. All rights reserved.

A Novel Method for Enhancing Strains' Biodegradation of 4-Chloronitrobenzene.

PubMed

Li, Tian; Zhang, Tian C; He, Lin

2017-12-20

This paper introduces a novel approach to enhance the strains' biodegradation of 4-chloronitrobenzene by utilizing the synergistic effect of the organic reductant mannitol and the substrate beef extraction. Our results demonstrate that 4-chloronitrobenzene could not be an available nitrogen source to support target strains' growth, which induced the limited 4-chloronitrobenzene biodegradation. In addition, the organic reducing agent and substrate had a better synergistic effect than inorganic reducing agent and substrate to enhance the strains' 4-chloronitrobenzene cometabolic biodegradation. Employing the synergistic effect of the optimal mixture (mannitol and beef extraction), the biodegradation rates of 50mgL -1 4-chloronitrobenzene by seven of the ten target strains were enhanced up to 100% from previous removals of no more than 19.1% after 7days. Three of the strains could even completely degrade 100mgL -1 4-chloronitrobenzene while five strains degraded over 91.4%. The method has good potential to enhance bioremediation of various 4-Chloronitrobenzene-contaminated environments as mannitol and beef extraction are non-toxic to the environment. Copyright © 2017 Elsevier B.V. All rights reserved.

Improving ready biodegradability testing of fatty amine derivatives.

PubMed

van Ginkel, C G; Gancet, C; Hirschen, M; Galobardes, M; Lemaire, Ph; Rosenblom, J

2008-09-01

This study assesses the biodegradation potential of a number of fatty amine derivatives in tests following the OECD guidelines for ready biodegradability. A number of methods are used to reduce toxicity and improve the bioavailability of the fatty amine derivatives in these tests. Alkyl-1,3-diaminopropanes and octadecyltrimethylammonium chloride are toxic to microorganisms at concentrations used in OECD ready biodegradability tests. The concentration of these fatty amine derivatives in the aqueous phase can be reduced by reacting humic, or lignosulphonic acids with the derivatives or through the addition of silica gel to the test bottles. Using these non-biodegradable substances, ready biodegradability test results were obtained with tallow-1,3-diaminopropane and octadecyltrimethylammonium chloride. Demonstration of the ready biodegradability of the water-insoluble dioctadecylamine under the prescribed standard conditions is almost impossible due to the limited bioavailability of this compound. However, ready biodegradability results were achieved by using very low initial test substance concentrations and by introducing an organic phase. The contents of the bottles used to assess the biodegradability of dioctadecylamine were always mixed. False negative biodegradability results obtained with the fatty amine derivatives studied are the result of toxic effects and/or limited bioavailability. The aids investigated therefore improve ready biodegradability testing.

``Recycling'' Geophysics: Monitoring and Isotopic Analysis of Engineered Biological Systems

NASA Astrophysics Data System (ADS)

Doherty, R.; Singh, K. P.; Ogle, N.; Ntarlagiannis, D.

2010-12-01

The emerging sub discipline of biogeophysics has provoked debate on the mechanisms of microbial processes that may contribute to geophysical signatures. At field scales geophysical signatures are often non unique due to the many parameters (physical, chemical, and biological) that are involved. It may be easier to apply geophysical techniques such as electrodic potential (EP), self potential (SP) and induced polarization (IP) to engineered biological systems where there is a degree of control over the design of the physical and chemical domain. Here we present results of a column experiment that was designed to anaerobically biodegrade dissolved organic matter in landfill leachate. The column utilises a recycled porous media (concrete) to help sequester organic carbon. Electrodic potential, self potential and induced polarisation are used in conjunction with chemical and isotopic techniques to monitor the effectiveness of this approach. Preliminary carbon and oxygen isotopic analysis on concrete from the column in contact with leachate show isotopic enrichment suggesting abiotic precipitation of carbonates.

Development and application of screening tools for biodegradation in water-sediment systems and soil.

PubMed

Junker, Thomas; Coors, Anja; Schüürmann, Gerrit

2016-02-15

Two new screening-test systems for biodegradation in water-sediment systems (WSST; Water-Sediment Screening Tool) and soil (SST; Soil Screening Tool) were developed in analogy with the water-only test system OECD 301C (MITI-test). The test systems could be applied successfully to determine reproducible experimental mineralization rates and kinetics on the screening-test level for fifteen organic chemicals in water (MITI), water-sediment (WSST) and soil (SST). Substance-specific differences were observed for mineralization compared among the three test systems. Based on mineralization rate and mineralization half-life, the fifteen compounds could be grouped into four biodegradation categories: substances with high mineralization and a half-life <28 days in (1) all three test systems, (2) only in the MITI test and in the WSST, (3) only in the SST, and (4) none of the test systems. The observed differences between the MITI results and the WSST and SST biodegradation rates of the compounds do not reflect their (reversible) sorption into organic matter in terms of experimental K(oc) values and log D values for the relevant pH range. Regarding mineralization kinetics we recommend to determine the lag-phase, mineralization half-life and mineralization rate using a 5-parameter logistic regression for degradation curves with and without lag-phase. Experimental data obtained with the WSST and the SST could be verified by showing good agreement with biodegradation data from databases and literature for the majority of compounds tested. Thus, these new screening-tools for water-sediment and soil are considered suitable to determine sound and reliable quantitative mineralization data including mineralization kinetics in addition to the water-only ready biodegradability tests according to OECD 301. Copyright © 2015 Elsevier B.V. All rights reserved.

Partitioning microbial respiration between jet fuel and native organic matter in an organic-rich long time-contaminated aquifer.

PubMed

Bugna, G C; Chanton, J P; Stauffer, T B; MacIntyre, W G; Libelo, E L

2005-07-01

The relative importance of jet fuel biodegradation relative to the respiration of natural organic matter in a contaminated organic-rich aquifer underlying a fire training area at Tyndall Air Force Base, Florida, USA was determined with isotopic measurements. Thirteen wells were sampled and analyzed for BTX (benzene, toluene, xylene), dissolved inorganic carbon (DIC) and CH4 concentrations, and delta13C and 14C of DIC. Results range from non-detectable to 3790 ppb, 1.4-24 mM, 0.2-776 microM, +5.8 per thousand to -22 per thousand, and from 52 to 99 pmc, respectively. Residual fuel was confined to two center wells underlying the fire training area. DIC and CH4 concentrations were elevated down-gradient of the contamination, but also at sites that were not in the apparent flow path of the contaminated groundwater. DIC exhibited greatest delta13C enrichment at highest DIC and CH4 concentrations indicating that CH4 production was an important respiration mode. Radiocarbon-depleted DIC was observed at sites with high hydrocarbon concentrations and down-gradient of the site. The results indicate that while natural attenuation was not rapidly reducing the quantity of free product overlying the aquifer at the site of contamination, it was at least constraining its flow away from the spill site. Apparently under the conditions of this study, BTX was degraded as rapidly as it was dissolved.

Effect of humic acids on intestinal viscosity, leaky gut and ammonia excretion in a 24 h feed restriction model to induce intestinal permeability in broiler chickens

USDA-ARS?s Scientific Manuscript database

Humic acids (HA) are produced by biodegradation of organic matter that involves physical, chemical and microbiological processes, hence, HA are a complex mixture of many different acids containing carboxyl and phenolate groups. The purpose of this study was to evaluate the effect of HA on intestina...

Carbon Dioxide Corrosion and Acetate: A Hypothesis on the Influence of Microorganisms

DTIC Science & Technology

2008-11-01

thermocatalytic degradation of kero- gen,5 oxidation of suitable acid precursors," "and the pyrolytic destruction of kerogen or oil components.*IS... oil industry. Both chemical compounds can be produced and consumed by microorganisms during the anaerobic biodegradation of organic matter- including...hydrocarbons. We contend that the principles governing anaerobic biodegration activity can be extrapolated to above ground oil production facilities

Dissolved organic matter composition and biodegradability in a permafrost-dominated watershed network in central Siberia

NASA Astrophysics Data System (ADS)

Coble, A. A.; Rodriguez-Cardona, B.; Wymore, A.; Prokishkin, A. S.; Kolosov, R.; McDowell, W. H.

2016-12-01

Thawing permafrost soils can mobilize large quantities of dissolved organic matter (DOM) from soils to headwater streams, and DOM may undergo rapid transformations in streams and rivers in transit to the Arctic Ocean. With climate change an increased frequency of fire is also expected, which will further alter the DOM entering streams, and may contribute to changes in its biodegradability. Elucidating how DOM composition varies across a fire gradient within a river network underlain by continuous permafrost will therefore improve our understanding of the impact of climate change on Arctic ecosystems and its role in the global carbon cycle. To determine DOM composition we measured optical properties via excitation-emission matrices (EEMs) and subsequent parallel factor analysis across a spatially extensive collection of sites in central Siberia. Within a subset of streams in the Nizhnyaya Tunguska watershed network, we also measured biodegradable dissolved organic carbon (BDOC) incubated at in situ temperatures over a 7 day period during spring freshet on two dates in early June. Despite clear changes in optical properties of DOM and background DOC concentration along the fire gradient (range: 3 to >100 y since burn) BDOC did not vary systematically with years since fire for either incubation date. In the first incubation conducted near peak flow BDOC ranged from negligible to 7.6% (BDOC concentration = negligible to 1.4 mg C L-1) within a 7 day period. In the second incubation conducted 5 days later BDOC was negligible across all sites (as both a percentage and a concentration). Our results suggest that DOC exported from permafrost soils in the central Siberian plateau is relatively unreactive at in situ temperatures over 7 day time scales, which contrasts with previous studies conducted in watersheds underlain with Yedoma outcrops where biodegradability comprises a large fraction of DOC. Our preliminary results suggest that melting of permafrost soils in central Siberia may export large quantities of C to the Arctic Ocean that are not rapidly degraded in streams and rivers.

Photo- and bio-reactivity patterns of dissolved organic matter from biomass and soil leachates and surface waters in a subtropical wetland.

PubMed

Chen, Meilian; Jaffé, Rudolf

2014-09-15

Dissolved organic carbon (DOC) measurements and optical properties were applied to assess the photo- and bio-reactivity of dissolved organic matter (DOM) from different sources, including biomass leaching, soil leaching and surface waters in a subtropical wetland ecosystem. Samples were exposed to light and/or dark incubated through controlled laboratory experiments. Changes in DOC, ultraviolet (UV-Vis) visible absorbance, and excitation-emission matrix (EEM) fluorescence combined with parallel factor analysis (PARAFAC) were performed to assess sample degradation. Degradation experiments showed that while significant amounts of DOC were consumed during bio-incubation for biomass leachates, a higher degree of bio-recalcitrance for soil leachate and particularly surface waters was displayed. Photo- and bio-humification transformations were suggested for sawgrass, mangrove, and seagrass leachates, as compared to substantial photo-degradation and very little to almost no change after bio-incubation for the other samples. During photo-degradation in most cases the EEM-PARAFAC components displayed photo-decay as compared to a few cases which featured photo-production. In contrast during bio-incubation most EEM-PARAFAC components proved to be mostly bio-refractory although some increases and decreases in abundance were also observed. Furthermore, the sequential photo- followed by bio-degradation showed, with some exceptions, a "priming effect" of light exposure on the bio-degradation of DOM, and the combination of these two processes resulted in a DOM composition more similar to that of the natural surface water for the different sub-environments. In addition, for leachate samples there was a general enrichment of one of the EEM-PARAFAC humic-like component (Ex/Em: <260(305)/416 nm) during photo-degradation and an enrichment of a microbial humc-like component (Ex/Em: <260(325)/406 nm and of a tryptophan-like component (Ex/Em: 300/342 nm) during the bio-degradation process. This study exemplifies the effectiveness of optical property and EEM-PARAFAC in the assessment of DOM reactivity and highlights the importance of the coupling of photo- and bio-degradation processes in DOM degradation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Stimulation of oxygen to bioanode for energy recovery from recalcitrant organic matter aniline in microbial fuel cells (MFCs).

PubMed

Cheng, Hao-Yi; Liang, Bin; Mu, Yang; Cui, Min-Hua; Li, Kun; Wu, Wei-Min; Wang, Ai-Jie

2015-09-15

The challenge of energy generation from biodegradation of recalcitrant organics in microbial fuel cells (MFCs) is mainly attributed to their persistence to degradation under anaerobic condition in anode chamber of MFCs. In this work, we demonstrated that electricity generation from aniline, a typical recalcitrant organic matter under anaerobic condition was remarkably facilitated by employing oxygen into bioanode of MFCs. By exposing bioanode to air, electrons of 47.2 ± 6.9 C were recovered with aniline removal efficiency of 91.2 ± 2.2% in 144 h. Limited oxygen supply (the anodic headspace was initially filled with air and then closed) resulted in the decrease of electrons recovery and aniline removal efficiency by 52.5 ± 9.4% and 74.2 ± 2.1%, respectively, and further decline by respective 64.3 ± 4.5% and 82.7 ± 1.0% occurred under anaerobic condition. Community analysis showed that anode biofilm was predominated by several aerobic aniline degrading bacteria (AADB) and anode-respiration bacteria (ARB), which likely cooperated with each other and finally featured the energy recovery from aniline. Cyclic voltammetry indicated that anodic bacteria transferred electrons to anode mainly through electron shuttle. This study provided a new sight to acquaint us with the positive role of oxygen in biodegradation of recalcitrant organics on anode as well as electricity generation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Microbial Community Composition of Polyhydroxyalkanoate-Accumulating Organisms in Full-Scale Wastewater Treatment Plants Operated in Fully Aerobic Mode

PubMed Central

Oshiki, Mamoru; Onuki, Motoharu; Satoh, Hiroyasu; Mino, Takashi

2013-01-01

The removal of biodegradable organic matter is one of the most important objectives in biological wastewater treatments. Polyhydroxyalkanoate (PHA)-accumulating organisms (PHAAOs) significantly contribute to the removal of biodegradable organic matter; however, their microbial community composition is mostly unknown. In the present study, the microbial community composition of PHAAOs was investigated at 8 full-scale wastewater treatment plants (WWTPs), operated in fully aerobic mode, by fluorescence in situ hybridization (FISH) analysis and post-FISH Nile blue A (NBA) staining techniques. Our results demonstrated that 1) PHAAOs were in the range of 11–18% in the total number of cells, and 2) the microbial community composition of PHAAOs was similar at the bacterial domain/phylum/class/order level among the 8 full-scale WWTPs, and dominant PHAAOs were members of the class Alphaproteobacteria and Betaproteobacteria. The microbial community composition of α- and β-proteobacterial PHAAOs was examined by 16S rRNA gene clone library analysis and further by applying a set of newly designed oligonucleotide probes targeting 16S rRNA gene sequences of α- or β-proteobacterial PHAAOs. The results demonstrated that the microbial community composition of PHAAOs differed in the class Alphaproteobacteria and Betaproteobacteria, which possibly resulted in a different PHA accumulation capacity among the WWTPs (8.5–38.2 mg-C g-VSS−1 h−1). The present study extended the knowledge of the microbial diversity of PHAAOs in full-scale WWTPs operated in fully aerobic mode. PMID:23257912

Non-steady state simulation of BOM removal in drinking water biofilters: model development.

PubMed

Hozalski, R M; Bouwer, E J

2001-01-01

A numerical model was developed to simulate the non-steady-state behavior of biologically-active filters used for drinking water treatment. The biofilter simulation model called "BIOFILT" simulates the substrate (biodegradable organic matter or BOM) and biomass (both attached and suspended) profiles in a biofilter as a function of time. One of the innovative features of BIOFILT compared to previous biofilm models is the ability to simulate the effects of a sudden loss in attached biomass or biofilm due to filter backwash on substrate removal performance. A sensitivity analysis of the model input parameters indicated that the model simulations were most sensitive to the values of parameters that controlled substrate degradation and biofilm growth and accumulation including the substrate diffusion coefficient, the maximum rate of substrate degradation, the microbial yield coefficient, and a dimensionless shear loss coefficient. Variation of the hydraulic loading rate or other parameters that controlled the deposition of biomass via filtration did not significantly impact the simulation results.

Microbial utilisation of natural organic wastes

NASA Astrophysics Data System (ADS)

Ilyin, V. K.; Smirnov, I. A.; Soldatov, P. E.; Korniushenkova, I. N.; Grinin, A. S.; Lykov, I. N.; Safronova, S. A.

2004-03-01

The waste management strategy for the future should meet the benefits of humanity safety, respect principals of planet ecology, and compatibility with other habitability systems. For these purpose the waste management technologies, relevant to application of the biodegradation properties of bacteria are of great value. The biological treatment method is based upon the biodegradation of organic substances by various microorganisms. The advantage of the biodegradation waste management in general: it allows to diminish the volume of organic wastes, the biological hazard of the wastes is controlled and this system may be compatible with the other systems. The objectives of our study were: to evaluate effectiveness of microbial biodegradation of non-pretreated substrate, to construct phneumoautomatic digester for organic wastes biodegradation and to study microbial characteristics of active sludge samples used as inoculi in biodegradation experiment. The technology of vegetable wastes treatment was elaborated in IBMP and BMSTU. For this purpose the special unit was created where the degradation process is activated by enforced reinvention of portions of elaborated biogas into digester. This technology allows to save energy normally used for electromechanical agitation and to create optimal environment for anaerobic bacteria growth. The investigations were performed on waste simulator, which imitates physical and chemical content of food wastes calculated basing on the data on food wastes of moderate Russian city. The volume of created experimental sample of digester is 40 l. The basic system elements of device are digesters, gas receiver, remover of drops and valve monitoring and thermal control system. In our testing we used natural food wastes to measure basic parameters and time of biodegradation process. The diminution rate of organic gained 76% from initial mass taking part within 9 days of fermentation. The biogas production achieved 46 l per 1 kg of substrate. The microbial studies of biodegradation process revealed following peculiarities: gradual quantitative increasing of Lactobacillus sp. (from 10 3 to 10 5 colony forming units (CFU) per ml), activation of Clostridia sp. (from 10 2 to 10 4 CFU/ml) and elimination of aerobic conventional pathogens ( Enterobacteriaceae sp., Protea sp., staphylococci). The obtained results allow to evaluate effectiveness of proposed technology and to determine the leading role of lactobacilli and clostridia in process of natural wastes biodegradation. Our further investigations shall further be concentrated on creation of artificial inoculi for launching of food wastes biodegradation. These inoculi will include active and adapted strains of clostridia and lactobacilli.

Characterization of soluble microbial products as precursors of disinfection byproducts in drinking water supply.

PubMed

Liu, Jin-Lin; Li, Xiao-Yan; Xie, Yue-Feng; Tang, Hao

2014-02-15

Water pollution by wastewater discharge can cause the problem of disinfection byproducts (DBPs) in drinking water supply. In this study, DBP formation characteristics of soluble microbial products (SMPs) as the main products of wastewater organic biodegradation were investigated. The results show that SMPs can act as DBP precursors in simulated wastewater biodegradation process. Under the experimental conditions, stabilized SMPs had DBPFP (DBP formation potential) yield of around 5.6 μmol mmol(-1)-DOC (dissolved organic carbon) and DBP speciation profile different from that of the conventional precursor, natural organic matter (NOM). SMPs contained polysaccharides, proteins, and humic-like substances, and the latter two groups can act as reactive DBP precursors. SMP fraction with molecular weight of <1 kDa accounted for 85% of the organic carbon and 65% of the DBP formation. As small SMP molecules are more difficult to remove by conventional water treatment processes, more efforts are needed to control wastewater-derived DBP problem in water resource management. Copyright © 2013 Elsevier B.V. All rights reserved.

Dissolved organic matter in the unsaturated zone: the view from the cave

NASA Astrophysics Data System (ADS)

Baker, A.; Duan, W.; Rutlidge, H.; McDonough, L.; Oudone, P.; Meredith, K.; Andersen, M. S.; O'Carroll, D. M.; Coleborn, K.; Treble, P. C.

2017-12-01

Soil organic matter content is typically a few percent of the total soil composition. Diffuse recharge can mobilise some of this soil-derived organic matter. While soil pore water dissolved organic matter (DOM) concentrations are up to 100 ppm, the resulting groundwater dissolved organic matter concentration is typically less than 2ppm. Dissolved organic matter transported from the soil can be both biodegraded and sorbed to minerals, and the relative importance of these two processes in the unsaturated zone is poorly understood. Caves in karstified limestone uniquely provide direct access to water percolating from the soil to the groundwater. Cave percolation waters can be analysed for their DOM concentration and character. This provides insights into the extent and type of biological and chemical processing of DOM during transport from the soil to the groundwater. We determine the concentration and characteristics of DOM in cave percolation waters using liquid chromatography (LC-OCD) and optical spectrophotometry (fluorescence and absorbance). We sample DOM from multiple caves in SE Australia (Cathedral Cave, Wellington; South Glory and Harrie Wood Caves, Yarrangobilly), permitting comparison of unsaturated zone DOM properties at different depths (up to 30m below land surface) and different climate zones (montane and temperate). We use caves with long-term hydrological monitoring programs so that DOM in waters of contrasting residence times can be compared. Additionally, we compare these cave percolation water DOM characteristics to those from local and regional groundwater, sampled from nearby wells. Our results will help improve our understanding of how DOM is processed from soil to groundwater, and is also relevant to speleothem scientists interested in using organic matter preserved in speleothems as a paleoclimate or paleoenvironmental proxy.

In vivo characterization of magnesium alloy biodegradation using electrochemical H2 monitoring, ICP-MS, and XPS.

PubMed

Zhao, Daoli; Wang, Tingting; Nahan, Keaton; Guo, Xuefei; Zhang, Zhanping; Dong, Zhongyun; Chen, Shuna; Chou, Da-Tren; Hong, Daeho; Kumta, Prashant N; Heineman, William R

2017-03-01

The effect of widely different corrosion rates of Mg alloys on four parameters of interest for in vivo characterization was evaluated: (1) the effectiveness of transdermal H 2 measurements with an electrochemical sensor for noninvasively monitoring biodegradation compared to the standard techniques of in vivo X-ray imaging and weight loss measurement of explanted samples, (2) the chemical compositions of the corrosion layers of the explanted samples by XPS, (3) the effect on animal organs by histology, and (4) the accumulation of corrosion by-products in multiple organs by ICP-MS. The in vivo biodegradation of three magnesium alloys chosen for their widely varying corrosion rates - ZJ41 (fast), WKX41 (intermediate) and AZ31 (slow) - were evaluated in a subcutaneous implant mouse model. Measuring H 2 with an electrochemical H 2 sensor is a simple and effective method to monitor the biodegradation process in vivo by sensing H 2 transdermally above magnesium alloys implanted subcutaneously in mice. The correlation of H 2 levels and biodegradation rate measured by weight loss shows that this non-invasive method is fast, reliable and accurate. Analysis of the insoluble biodegradation products on the explanted alloys by XPS showed all of them to consist primarily of Mg(OH) 2 , MgO, MgCO 3 and Mg 3 (PO 4 ) 2 with ZJ41 also having ZnO. The accumulation of magnesium and zinc were measured in 9 different organs by ICP-MS. Histological and ICP-MS studies reveal that there is no significant accumulation of magnesium in these organs for all three alloys; however, zinc accumulation in intestine, kidney and lung for the faster biodegrading alloy ZJ41 was observed. Although zinc accumulates in these three organs, no toxicity response was observed in the histological study. ICP-MS also shows higher levels of magnesium and zinc in the skull than in the other organs. Biodegradable devices based on magnesium and its alloys are promising because they gradually dissolve and thereby avoid the need for subsequent removal by surgery if complications arise. In vivo biodegradation rate is one of the crucial parameters for the development of these alloys. Promising alloys are first evaluated in vivo by being implanted subcutaneously in mice for 1month. Here, we evaluated several magnesium alloys with widely varying corrosion rates in vivo using multiple characterization techniques. Since the alloys biodegrade by reacting with water forming H 2 gas, we used a recently demonstrated, simple, fast and noninvasive method to monitor the biodegradation process by just pressing the tip of a H 2 sensor against the skin above the implant. The analysis of 9 organs (intestine, kidney, spleen, lung, heart, liver, skin, brain and skull) for accumulation of Mg and Zn revealed no significant accumulation of magnesium in these organs. Zinc accumulation in intestine, kidney and lung was observed for the faster corroding implant ZJ41. The surfaces of explanted alloys were analyzed to determine the composition of the insoluble biodegradation products. The results suggest that these tested alloys are potential candidates for biodegradable implant applications. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

40 CFR 265.1084 - Waste determination procedures.

Code of Federal Regulations, 2014 CFR

2014-07-01

... to determine the organic biodegradation efficiency (Rbio) for a treated hazardous waste. (i) The... Where: Rbio = Organic biodegradation efficiency, percent. Fbio = Fraction of organic biodegraded as... to determine the actual organic mass biodegradation rate (MRbio) for a treated hazardous waste. (i...

Microbial Factors Rather Than Bioavailability Limit the Rate and Extent of PAH Biodegradation in Aged Crude Oil Contaminated Model Soils

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

Huesemann, Michael H.; Hausmann, Tom S.; Fortman, Timothy J.

The rate and extent of PAH biodegradation in a set of aged, crude oil contaminated model soils were measured in 90-week slurry bioremediation experiments. Soil properties such as organic matter content, mineral type, particle diameter, surface area, and porosity did not significantly influence the PAH biodegradation kinetics among the ten different model soils. A comparison of aged and freshly spiked soils indicates that aging affects the biodegradation rates and extents only for higher molecular weight PAHs while the effects of aging are insignificant for 3-ring PAHs and total PAHs. In all model soils with the exception of kaolinite clay, themore » rate of abiotic desorption was faster than the rate of biodegradation during the initial phase of bioremediation treatment indicating that PAH biodegradation was limited by microbial factors. Similarly, any of the higher molecular weight PAHs that were still present after 90 weeks of treatment were released rapidly during abiotic desorption tests which demonstrates that bioavailability limitations were not responsible for the recalcitrance of these hydrocarbons. Indeed, an analysis of microbial counts indicates that a severe reduction in hydrocarbon degrader populations may be responsible for the observed incomplete PAH biodegradation. It can therefore be concluded that the recalcitrance of PAHs during bioremediation is not necessarily due to bioavailability limitations and that these residual contaminants might, therefore, pose a greater risk to environmental receptors than previously thought.« less

Development auxiliaries for dyeing polyester with disperse dyes at low temperatures

NASA Astrophysics Data System (ADS)

Carrion-Fite, F. J.; Radei, S.

2017-10-01

High-molecular weight organic compounds known as carriers are widely used to expedite polyester dyeing at atmospheric pressure at 100 °C. However, carriers are usually poorly biodegradable and can partially plasticize fibres. Also, dyeing at temperatures above 100 °C in the absence of a carrier entails using expensive equipment. In this work, we developed an alternative method for dyeing polyester at temperatures below 100 °C that reduces energy expenses, dispenses with the need to invest in new equipment and avoids the undesirable effects of non-biodegradable carriers. The method uses disperse dyes in a microemulsion containing a low proportion of a non-toxic organic solvent and either of two alternative development auxiliaries (coumarin and o-vanillin) that is prepared with the aid of ultrasound.

Pyrolysis-combustion 14C dating of soil organic matter

USGS Publications Warehouse

Wang, Hongfang; Hackley, Keith C.; Panno, S.V.; Coleman, D.D.; Liu, J.C.-L.; Brown, J.

2003-01-01

Radiocarbon (14C) dating of total soil organic matter (SOM) often yields results inconsistent with the stratigraphic sequence. The onerous chemical extractions for SOM fractions do not always produce satisfactory 14C dates. In an effort to develop an alternative method, the pyrolysis-combustion technique was investigated to partition SOM into pyrolysis volatile (Py-V) and pyrolysis residue (Py-R) fractions. The Py-V fractions obtained from a thick glacigenic loess succession in Illinois yielded 14C dates much younger but more reasonable than the counterpart Py-R fractions for the soil residence time. Carbon isotopic composition (??13C) was heavier in the Py-V fractions, suggesting a greater abundance of carbohydrate- and protein-related constituents, and ??13C was lighter in the Py-R fractions, suggesting more lignin- and lipid-related constituents. The combination of 14C dates and ??13C values indicates that the Py-V fractions are less biodegradation resistant and the Py-R fractions are more biodegradation resistant. The pyrolysis-combustion method provides a less cumbersome approach for 14C dating of SOM fractions. With further study, this method may become a useful tool for analyzing unlithified terrestrial sediments when macrofossils are absent. ?? 2003 University of Washington. Published by Elsevier Inc. All rights reserved.

Culture-dependent and culture-independent characterization of potentially functional biphenyl-degrading bacterial community in response to extracellular organic matter from Micrococcus luteus.

PubMed

Su, Xiao-Mei; Liu, Yin-Dong; Hashmi, Muhammad Zaffar; Ding, Lin-Xian; Shen, Chao-Feng

2015-05-01

Biphenyl (BP)-degrading bacteria were identified to degrade various polychlorinated BP (PCB) congers in long-term PCB-contaminated sites. Exploring BP-degrading capability of potentially useful bacteria was performed for enhancing PCB bioremediation. In the present study, the bacterial composition of the PCB-contaminated sediment sample was first investigated. Then extracellular organic matter (EOM) from Micrococcus luteus was used to enhance BP biodegradation. The effect of the EOM on the composition of bacterial community was investigated by combining with culture-dependent and culture-independent methods. The obtained results indicate that Proteobacteria and Actinobacteria were predominant community in the PCB-contaminated sediment. EOM from M. luteus could stimulate the activity of some potentially difficult-to-culture BP degraders, which contribute to significant enhancement of BP biodegradation. The potentially difficult-to-culture bacteria in response to EOM addition were mainly Rhodococcus and Pseudomonas belonging to Gammaproteobacteria and Actinobacteria respectively. This study provides new insights into exploration of functional difficult-to-culture bacteria with EOM addition and points out broader BP/PCB degrading, which could be employed for enhancing PCB-bioremediation processes. © 2015 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

New insights into the source of decadal increase in chemical oxygen demand associated with dissolved organic carbon in Dianchi Lake.

PubMed

Guo, Wei; Yang, Feng; Li, Yanping; Wang, Shengrui

2017-12-15

Dissolved organic carbon (DOC) can be used an alternative index of water quality instead of chemical oxygen demand (COD) to reflect the organic pollution in water. The monitoring data of water quality in a long-term (1990-2013) from Dianchi Lake confirmed the increase trend of COD concentration in the lake since 2007. The similarities and differences in the DOC components between the lake and its sources and the contribution from allochthonous and autochthonous DOC to the total DOC in this lake were determined to elucidate the reason of COD increase based on C/N atomic ratios, stable isotope abundance of carbon and nitrogen, UV-visible spectroscopy, three-dimensional excitation-emission matrix (3DEEM) fluorescence spectroscopy. The terrigenous organic matter showed humic-like fluorescence, and the autochthonous organic matter showed tryptophan-like components. Agricultural runoff (9.5%), leaf litter (7.5%) and urban runoff (13.2%) were the main sources of DOC in the lake. Sewage tail was a major source of organic materials, 3DEEM for the indicates that sewage tail DOC composition did not change markedly over the biodegradation period, indicating that sewage tail contains a high load of DOC that is resistant to further biodegradation and subsequently accumulates in the lake. The change of land use in the catchment and the increase of sewage tail load into the lake are the key factors for the increase in COD concentration in Dianchi Lake. Thus, the lake should be protected by controlling the pollution from the urban nonpoint sources and refractory composition in point sources. Copyright © 2017 Elsevier B.V. All rights reserved.

Determination of factors responsible for the bioweathering of copper minerals from organic-rich copper-bearing Kupferschiefer black shale.

PubMed

Włodarczyk, Agnieszka; Szymańska, Agata; Skłodowska, Aleksandra; Matlakowska, Renata

2016-04-01

The aim of this study was to investigate the bioweathering of copper minerals present in the alkaline, copper-bearing and organic-rich Kupferschiefer black shale through the action of a consortium of indigenous lithobiontic, heterotrophic, neutrophilic bacteria isolated from this sedimentary rock. The involvement of microorganisms in the direct/enzymatic bioweathering of fossil organic matter of the rock was confirmed. As a result of bacterial activity, a spectrum of various organic compounds such as urea and phosphoric acid tributyl ester were released from the rock. These compounds indirectly act on the copper minerals occurring in the rock and cause them to weather. This process was reflected in the mobilization of copper, iron and sulfur and in changes in the appearance of copper minerals observed under reflected light. The potential role of identified enzymes in biodegradation of fossil organic matter and role of organic compounds released from black shale as a result of this process in copper minerals weathering was discussed. The presented results provide a new insight into the role of chemical compounds released by bacteria during fossil organic matter bioweathering potentially important in the cycling of copper and iron deposited in the sedimentary rock. The originality of the described phenomenon lies in the fact that the bioweathering of fossil organic matter and, consequently, of copper minerals occur simultaneously in the same environment, without any additional sources of energy, electrons and carbon. Copyright © 2016 Elsevier Ltd. All rights reserved.

Characterization and prediction of organic nitrogen biodegradability during anaerobic digestion: A bioaccessibility approach.

PubMed

Bareha, Y; Girault, R; Jimenez, J; Trémier, A

2018-04-26

Prediction of organic nitrogen mineralization into ammonium during anaerobic digestion is required for optimizing substitution of mineral fertilizer by digestates. The aim of this study was to understand organic nitrogen biodegradability and to investigate how it can be predicted from carbon biodegradability, and nitrogen bioaccessibility, respectively. Bioaccessibility was assessed using fractionation methods based on sequential extractions. Results showed that organic nitrogen was present in fractions whose bioaccessibility levels differed. Organic nitrogen and carbon biodegradability were also determined and compared. Results highlighted two groups of substrates: the first with an initial NH 4 + /TKN < 30%, whose carbon and nitrogen biodegradability are similar; the second with an initial NH 4 + /TKN > 30%, whose carbon and nitrogen biodegradability differ significantly. To enable prediction on all substrates, partial least square (PLS) regressions were carried out to link organic nitrogen bioaccessibility indicators to biodegradability. The models successfully predicted organic nitrogen biodegradability with a maximum prediction error of 10%. Copyright © 2018 Elsevier Ltd. All rights reserved.

Impacts of biochar on bioavailability of the fungicide azoxystrobin: a comparison of the effect on biodegradation rate and toxicity to the fungal community.

PubMed

Sopeña, Fatima; Bending, Gary D

2013-06-01

There is great interest in using biochar (BC) as a soil amendment to provide a long-term repository of carbon to mitigate climate change. BC can have major impacts on soil biogeochemical cycling processes, largely by the sorption and protection of organic matter from microbial turnover. Application of BC to agricultural soil could also affect the efficacy, fate and environmental impact of pesticides. In the current study we investigated the effect of BC on bioavailability of the fungicide azoxystrobin in soil. We found that application of BC had no effect on sorption or degradation of azoxystrobin, even at a rate of 2% w/w. While azoxystrobin reduced dehydrogenase activity, BC addition greatly increased dehydrogenase, although the inhibitory effect of azoxystrobin was still evident in BC amended soil. Using Terminal Restriction Fragment Length Polymorphism of fungal SSU rRNA gene ITS regions it was found that azoxystrobin altered the structure of the soil fungal community, although this effect was dampened by BC addition. BC application had minor effects on fungal community structure. We conclude that measurement of the effect of BC on pesticide bioavailability by analysis of biodegradation rate and non-target effects on fungal community structure gave contrasting conclusions. Copyright © 2013 Elsevier Ltd. All rights reserved.

Slowly biodegradable organic compounds impact the biostability of non-chlorinated drinking water produced from surface water.

PubMed

Hijnen, W A M; Schurer, R; Bahlman, J A; Ketelaars, H A M; Italiaander, R; van der Wal, A; van der Wielen, P W J J

2018-02-01

It is possible to distribute drinking water without a disinfectant residual when the treated water is biologically stable. The objective of this study was to determine the impact of easily and slowly biodegradable compounds on the biostability of the drinking water at three full-scale production plants which use the same surface water, and on the regrowth conditions in the related distribution systems. Easily biodegradable compounds in the drinking water were determined with AOC-P17/Nox during 2012-2015. Slowly biodegradable organic compounds measured as particulate and/or high-molecular organic carbon (PHMOC), were monitored at the inlet and after the different treatment stages of the three treatments during the same period. The results show that PHMOC (300-470 μg C L -1 ) was approximately 10% of the TOC in the surface water and was removed to 50-100 μg C L -1 . The PHMOC in the water consisted of 40-60% of carbohydrates and 10% of proteins. A significant and strong positive correlation was observed for PHMOC concentrations and two recently introduced bioassay methods for slowly biodegradable compounds (AOC-A3 and biomass production potential, BPC 14 ). Moreover, these three parameters in the biological active carbon effluent (BACF) of the three plants showed a positive correlation with regrowth in the drinking water distribution system, which was assessed with Aeromonas, heterotrophic plate counts, coliforms and large invertebrates. In contrast, the AOC-P17/Nox concentrations did not correlate with these regrowth parameters. We therefore conclude that slowly biodegradable compounds in the treated water from these treatment plants seem to have a greater impact on regrowth in the distribution system than easily biodegradable compounds. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sediment biomarker, bacterial community characterization of high arsenic aquifers in Jianghan Plain, China

PubMed Central

Ye, Hengpeng; Yang, Zeyu; Wu, Xiang; Wang, Jingwen; Du, Dongyun; Cai, Jian; Lv, Kangle; Chen, Huiyun; Mei, Jingkun; Chen, Mengqi; Du, Hong

2017-01-01

Representative biomarkers (e.g., n-alkanes), diversity and microbial community in the aquifers contaminated by high concentration of arsenic (As) in different sediment depth (0–30 m) in Jianghan Plain, Hubei, China, were analyzed to investigate the potential mechanism of As enrichment in groundwater. The concentration of As was abundant in top soil and sand, but not in clay. The analysis of the distribution of n-alkanes, CPI values, and wax to total n-alkane ratio (Wax(n)%) indicated that the organic matter (OM) from fresh terrestrial plants were abundant in the shallow sediment. However, n-alkanes have suffered from significant biodegradation from the depth of 16 m to 30 m. The deposition of fresh terrestrial derived organic matters may facilitate the release of As from sediment to groundwater in the sediment of 0–16 m. However, the petroleum derived organic matters may do the favor to the release of As in the deeper section of borehole (16 m to 30 m). The 16S rRNA gene sequences identification indicated that Acidobacteria, Actinomycetes and Hydrogenophaga are abundant in the sediments with high arsenic. Therefore, microbes and organic matters from different sources may play important roles in arsenic mobilization in the aquifers of the study area. PMID:28165031

The use of fly larvae for organic waste treatment.

PubMed

Čičková, Helena; Newton, G Larry; Lacy, R Curt; Kozánek, Milan

2015-01-01

The idea of using fly larvae for processing of organic waste was proposed almost 100 years ago. Since then, numerous laboratory studies have shown that several fly species are well suited for biodegradation of organic waste, with the house fly (Musca domestica L.) and the black soldier fly (Hermetia illucens L.) being the most extensively studied insects for this purpose. House fly larvae develop well in manure of animals fed a mixed diet, while black soldier fly larvae accept a greater variety of decaying organic matter. Blow fly and flesh fly maggots are better suited for biodegradation of meat processing waste. The larvae of these insects have been successfully used to reduce mass of animal manure, fecal sludge, municipal waste, food scrapes, restaurant and market waste, as well as plant residues left after oil extraction. Higher yields of larvae are produced on nutrient-rich wastes (meat processing waste, food waste) than on manure or plant residues. Larvae may be used as animal feed or for production of secondary products (biodiesel, biologically active substances). Waste residue becomes valuable fertilizer. During biodegradation the temperature of the substrate rises, pH changes from neutral to alkaline, ammonia release increases, and moisture decreases. Microbial load of some pathogens can be substantially reduced. Both larvae and digested residue may require further treatment to eliminate pathogens. Facilities utilizing natural fly populations, as well as pilot and full-scale plants with laboratory-reared fly populations have been shown to be effective and economically feasible. The major obstacles associated with the production of fly larvae from organic waste on an industrial scale seem to be technological aspects of scaling-up the production capacity, insufficient knowledge of fly biology necessary to produce large amounts of eggs, and current legislation. Technological innovations could greatly improve performance of the biodegradation facilities and decrease production costs. Copyright © 2014 Elsevier Ltd. All rights reserved.

Microbial utilisation of natural organic wastes.

PubMed

Ilyin, V K; Smirnov, I A; Soldatov, P E; Korniushenkova, I N; Grinin, A S; Lykov, I N; Safronova, S A

2004-03-01

The waste management strategy for the future should meet the benefits of humanity safety, respect principals of planet ecology, and compatibility with other habitability systems. For these purpose the waste management technologies, relevant to application of the biodegradation properties of bacteria are of great value. The biological treatment method is based upon the biodegradation of organic substances by various microorganisms. The advantage of the biodegradation waste management in general: it allows to diminish the volume of organic wastes, the biological hazard of the wastes is controlled, and this system may be compatible with the other systems. The objectives of our study were: to evaluate effectiveness of microbial biodegradation of non-pretreated substrate, to construct phneumoautomatic digester for organic wastes biodegradation, and to study microbial characteristics of active sludge samples used as inoculi in biodegradation experiment. The technology of vegetable wastes treatment was elaborated in IBMP and BMSTU. For this purpose the special unit was created where the degradation process is activated by enforced reinvention of portions of elaborated biogas into digester. This technology allows to save energy normally used for electromechanical agitation and to create optimal environment for anaerobic bacteria growth. The investigations were performed on waste simulator, which imitates physical and chemical content of food wastes calculated basing on the data on food wastes of moderate Russian city. The volume of created experimental sample of digester is 40 l. The basic system elements of device are digesters, gas receiver, remover of drops and valve monitoring and thermal control system. In our testing we used natural food wastes to measure basic parameters and time of biodegradation process. The diminution rate of organic gained 76% from initial mass taking part within 9 days of fermentation. The biogas production achieved 46 l per 1 kg of substrate. The microbial studies of biodegradation process revealed following peculiarities: (i) gradual quantitative increasing of Lactobacillus sp. (from 10(3) to 10(5) colony forming units (CFU) per ml), (ii) activation of Clostridia sp. (from 10(2) to 10(4)CFU/ml), (iii) elimination of aerobic conventional pathogens (Enterobacteriaceae sp., Protea sp., staphylococci). The obtained results allow to evaluate effectiveness of proposed technology and to determine the leading role of lactobacilli and clostridia in process of natural wastes biodegradation. Our further investigations shall further be concentrated on creation of artificial inoculi for launching of food wastes biodegradation. These inoculi will include active and adapted strains of clostridia and lactobacilli. c2003 Elsevier Ltd. All rights reserved.

Achilles heel of environmental risk from recycling of sludge to soil as amendment: A summary in recent ten years (2007-2016).

PubMed

Liu, Hong-Tao

2016-10-01

Recycling sludge as a soil amendment has both positive and negative effects because of its enrichment in both nutrients and contaminants. So far, the negative effect has to be extensively investigated that the severities of different types of contaminants also remain unclear. The environmental behavior and risk of organic contaminant and pharmaceuticals, heavy metal and salt as well as pathogenic microorganisms brought by sludge amendment are summarized and discussed here. Organic contaminants and pharmaceuticals are typically found at low concentrations in sludge, the risks from sludge-amended soil decrease over time owing to its biodegradability. On the other hand, application of sludge generally increases soil salinity, which may cause physiological damage to plants grown in sludge-amended soil. In some extent, this negative effect can be alleviated by means of dilution; however, greater attention should be paid to long term increasing possible risk of eutrophication. Heavy metal (particularly of mobile heavy metals, such as Cd) with high concentrations in sludge and soil receiving considerable sludge can cause its incremental abundance in soil and crop contamination, further posing risks to humans, but most cases showed that there remained not excessive in heavy metal caused by sludge amendment. It is worth noting that increasing soil organic matter content may reduce transfer of heavy metal from soil to crops, but not restrict its uptake by crops at all. Combined literature together, it is summarized that heavy metal becomes a relatively severe bottleneck in recycling of sludge as soil amendment due to its non-biodegradability and potential damage to health by adventuring contamination from agricultural products. Particular attention should therefore be paid to long term monitoring the change of heavy metals concentration in sludge amended soil. Copyright © 2016 Elsevier Ltd. All rights reserved.

Co-composting as an oxygen stabilization of an organic fraction of municipal solid waste and industrial sewage sludge.

PubMed

Milczarek, M; Neczaj, E; Parkitna, K

2013-01-01

The purpose of this work is to study the characteristics of the co-composting of municipal solid waste (MSW), sewage sludge, grass and sawdust. Differing proportions of biodegradable waste were investigated through changes of temperature, oxygen consumption, organic matters, moisture content, carbon, nitrogen, C/N ratio as well as heavy metals and pathogen microorganisms content. The present study has shown that addition of MSW above 10% had a negative impact on the composting process. The initial C/N of the mixtures with a higher MSW content was below 18. Lower losses of organic matter occurred during composting for the mixture with the highest addition of MSW. Although studies have shown that composting is a good method for the disposal of organic waste additional research is required in order to optimize the organic and nitrogen compounds degradation during the co-composting process. In conclusion, a 1:4:4:1 mixture of MSW:sewage sludge:grass:sawdust is recommended because it can achieve high temperature as well as the highest organic matter degradation and highest N content in the final composting product. The concentration of heavy and light metals in all composts was within the limits of regulation of the Polish Minister of Agriculture and Rural Development.

Environmental Assessment, Repair of the Dam at Non-Potable Reservoir #1, United States Air Force Academy, Colorado

DTIC Science & Technology

2015-08-01

crimping alone is insufficient. Hydro-mulch shall be applied using a color dye and the manufacturer’s recommended rate of an organic tackifier. D...drainage areas where erosion is probable. All erosion control blanket shall be 100% biodegradable , net- free, wood fiber (excelsior) or coconut...Manufactured biodegradable stakes (6-inch minimum) or wooden stakes (8-inch minimum) shall be used to anchor any erosion materials; metal staples

Biodegradation during contaminant transport in porous media: 1. mathematical analysis of controlling factors

NASA Astrophysics Data System (ADS)

Brusseau, Mark L.; Xie, Lily H.; Li, Li

1999-04-01

Interest in coupled biodegradation and transport of organic contaminants has expanded greatly in the past several years. In a system in which biodegradation is coupled with solute transport, the magnitude and rate of biodegradation is influenced not only by properties of the microbial population and the substrate, but also by hydrodynamic properties (e.g., residence time, dispersivity). By nondimensionalizing the coupled-process equations for transport and nonlinear biodegradation, we show that transport behavior is controlled by three characteristic parameters: the effective maximum specific growth rate, the relative half-saturation constant, and the relative substrate-utilization coefficient. The impact on biodegradation and transport of these parameters, which constitute various combinations of factors reflecting the influences of biotic and hydraulic properties of the system, are examined numerically. A type-curve diagram based on the three characteristic parameters is constructed to illustrate the conditions under which steady and non-steady transport is observed, and the conditions for which the linear, first-order approximation is valid for representing biodegradation. The influence of constraints to microbial growth and substrate utilization on contaminant transport is also briefly discussed. Additionally, the impact of biodegradation, with and without biomass growth, on spatial solute distribution and moments is examined.

Evaluation of the persistence of transformation products from ozonation of trace organic compounds - a critical review.

PubMed

Hübner, Uwe; von Gunten, Urs; Jekel, Martin

2015-01-01

Ozonation is an efficient treatment system to reduce the concentration of trace organic compounds (TrOCs) from technical aquatic systems such as drinking water, wastewater and industrial water, etc. Although it is well established that ozonation generally improves the removal of organic matter in biological post-treatment, little is known about the biodegradability of individual transformation products resulting from ozonation of TrOCs. This publication provides a qualified assessment of the persistence of ozone-induced transformation products based on a review of published product studies and an evaluation of the biodegradability of transformation products with the biodegradability probability program (BIOWIN) and the University of Minnesota Pathway Prediction System (UM-PPS). The oxidation of TrOCs containing the four major ozone-reactive sites (olefins, amines, aromatics and sulfur-containing compounds) follows well described reaction pathways leading to characteristic transformation products. Assessment of biodegradability revealed a high sensitivity to the formed products and hence the ozone-reactive site present in the target compound. Based on BIOWIN, efficient removal can be expected for products from cleavage of olefin groups and aromatic rings. In contrast, estimations and literature indicate that hydroxylamines and N-oxides, the major products from ozonation of secondary and tertiary amines are not necessarily better removed in biological post-treatment. According to UM-PPS, degradation of these products might even occur via reformation of the corresponding amine. Some product studies with sulfide-containing TrOCs showed a stoichiometric formation of sulfoxides from oxygen transfer reactions. However, conclusions on the fate of transformation products in biological post-treatment cannot be drawn based on BIOWIN and UM-PPS.

Biodegradability of dissolved organic carbon in the Yukon River and its tributaries: Seasonality and importance of inorganic nitrogen

USGS Publications Warehouse

Wickland, Kimberly P.; Aiken, George R.; Butler, Kenna D.; Dornblaser, Mark M.; RGM Spencer,; Striegl, Robert G.

2012-01-01

Northern high-latitude rivers transport large amounts of terrestrially derived dissolved organic matter (DOM) from boreal and arctic ecosystems to coastal areas and oceans. Current knowledge of the biodegradability of DOM in these rivers is limited, particularly for large rivers discharging to the Arctic Ocean. We conducted a seasonally comprehensive study of biodegradable dissolved organic carbon (BDOC) dynamics in the Yukon River and two of its tributaries in Alaska, USA. Distinct seasonal patterns of BDOC, consistent across a wide range of watershed size, indicate BDOC is transported year-round. Relative biodegradability (%BDOC) was greatest during winter, and decreased into spring and summer. Due to large seasonal differences in DOC concentration, the greatest concentrations of BDOC (mg C L−1) occurred during spring freshet, followed by winter and summer. While chemical composition of DOM was an important driver of BDOC, the overriding control of BDOC was mineral nutrient availability due to wide shifts in carbon (C) and nitrogen (N) stoichiometry across seasons. We calculated seasonal and annual loads of BDOC exported by the Yukon River by applying measured BDOC concentrations to daily water discharge values, and also by applying an empirical correlation between %BDOC and the ratio of DOC to dissolved inorganic N (DIN) to total DOC loads. The Yukon River exports ∼0.2 Tg C yr−1 as BDOC that is decomposable within 28 days. This corresponds to 12–18% of the total annual DOC export. Furthermore, we calculate that the six largest arctic rivers, including the Yukon River, collectively export ∼2.3 Tg C yr−1 as BDOC to the Arctic Ocean.

Quantitative structure-activity relationships for primary aerobic biodegradation of organic chemicals in pristine surface waters: starting points for predicting biodegradation under acclimatization.

PubMed

Nolte, Tom M; Pinto-Gil, Kevin; Hendriks, A Jan; Ragas, Ad M J; Pastor, Manuel

2018-01-24

Microbial biomass and acclimation can affect the removal of organic chemicals in natural surface waters. In order to account for these effects and develop more robust models for biodegradation, we have compiled and curated removal data for un-acclimated (pristine) surface waters on which we developed quantitative structure-activity relationships (QSARs). Global analysis of the very heterogeneous dataset including neutral, anionic, cationic and zwitterionic chemicals (N = 233) using a random forest algorithm showed that useful predictions were possible (Q ext 2 = 0.4-0.5) though relatively large standard errors were associated (SDEP ∼0.7). Classification of the chemicals based on speciation state and metabolic pathway showed that biodegradation is influenced by the two, and that the dependence of biodegradation on chemical characteristics is non-linear. Class-specific QSAR analysis indicated that shape and charge distribution determine the biodegradation of neutral chemicals (R 2 ∼ 0.6), e.g. through membrane permeation or binding to P450 enzymes, whereas the average biodegradation of charged chemicals is 1 to 2 orders of magnitude lower, for which degradation depends more directly on cellular uptake (R 2 ∼ 0.6). Further analysis showed that specific chemical classes such as peptides and organic halogens are relatively less biodegradable in pristine surface waters, resulting in the need for the microbial consortia to acclimate. Additional literature data was used to verify an acclimation model (based on Monod-type kinetics) capable of extrapolating QSAR predictions to acclimating conditions such as in water treatment, downstream lakes and large rivers under μg L -1 to mg L -1 concentrations. The framework developed, despite being based on multiple assumptions, is promising and needs further validation using experimentation with more standardised and homogenised conditions as well as adequate characterization of the inoculum used.

Interconnection of Key Microbial Functional Genes for Enhanced Benzo[a]pyrene Biodegradation in Sediments by Microbial Electrochemistry.

PubMed

Yan, Zaisheng; He, Yuhong; Cai, Haiyuan; Van Nostrand, Joy D; He, Zhili; Zhou, Jizhong; Krumholz, Lee R; Jiang, He-Long

2017-08-01

Sediment microbial fuel cells (SMFCs) can stimulate the degradation of polycyclic aromatic hydrocarbons in sediments, but the mechanism of this process is poorly understood at the microbial functional gene level. Here, the use of SMFC resulted in 92% benzo[a]pyrene (BaP) removal over 970 days relative to 54% in the controls. Sediment functions, microbial community structure, and network interactions were dramatically altered by the SMFC employment. Functional gene analysis showed that c-type cytochrome genes for electron transfer, aromatic degradation genes, and extracellular ligninolytic enzymes involved in lignin degradation were significantly enriched in bulk sediments during SMFC operation. Correspondingly, chemical analysis of the system showed that these genetic changes resulted in increases in the levels of easily oxidizable organic carbon and humic acids which may have resulted in increased BaP bioavailability and increased degradation rates. Tracking microbial functional genes and corresponding organic matter responses should aid mechanistic understanding of BaP enhanced biodegradation by microbial electrochemistry and development of sustainable bioremediation strategies.

High-rate wastewater treatment combining a moving bed biofilm reactor and enhanced particle separation.

PubMed

Helness, H; Melin, E; Ulgenes, Y; Järvinen, P; Rasmussen, V; Odegaard, H

2005-01-01

Many cities around the world are looking for compact wastewater treatment alternatives since space for treatment plants is becoming scarce. In this paper development of a new compact, high-rate treatment concept with results from experiments in lab-scale and pilot-scale are presented. The idea behind the treatment concept is that coagulation/floc separation may be used to separate suspended and colloidal matter (resulting in > 70% organic matter removal in normal wastewater) while a high-rate biofilm process (based on Moving Bed biofilm reactors) may be used for removing low molecular weight, easily biodegradable, soluble organic matter. By using flotation for floc/biomass separation, the total residence time for a plant according to this concept will normally be < 1 hour. A cationic polymer combined with iron is used as coagulant at low dosages (i.e. 1-2 mg polymer/l, 5-10 mg Fe/l) resulting in low sludge production (compared to conventional chemical treatment) and sufficient P-removal.

Organic geochemical study of domanik deposits, Tatarstan Republic.

NASA Astrophysics Data System (ADS)

Nosova, F. F.; Pronin, N. V.

2010-05-01

High-bituminous argillo-siliceous carbonate deposits of domanik formation (DF) occurring within pale depressions and down warps in the east of the Russian platform are treated by many investigators as a main source of oil and gas in the Volga-Ural province. In this study a special attention was turned to organic-rich rocks DF witch outcrop in the central part (Uratminskaya area 792, 806 boreholes) and in the west part (Sviyagskaya, 423) of the Tatarstan Republic. The aim of the present paper is to characterize the organic matter: origin, depositional environments, thermal maturity and biodegradation-weathering effects. Nowadays the most informative geochemical parameters are some biomarkers which qualitatively and are quantitatively defined from distributions of n-alkanes and branched alkanes. Biomarkers - it's original fingerprints of biomass of organic matter, that reflect molecular hydrocarbonic structure. The bulk, molecular composition of oil is initially a function of the type and maturity of the source rock from which it has been expelled, while the source rock type reflects both the nature of precursor organisms and the conditions of its deposition. Methodology used in this study included sampling, bitumen extraction, liquid-column chromatography and gas chromatography/mass spectrometry analyses. The bitumen was fractionated by column chromatography on silica gel. Non-aromatic or alifatics, aromatics and polar compounds were obtained. Alifatic were analysed by gas chromatography/mass spectrometry Percin Elmer. The hydrocarbons present in the sediments of DF and have a carbon numbers ranging from 12 through 38. The samples contain variably inputs from both terrigenous and non-terrigenous (probably marine algal) organic matter as evident in bimodal GC fingerprints of some samples. Pristane and phytane, also, occur in very high concentration in sample extracts. The relatively low Pr/Ph ratios, CPI and OEP<1 imply that the domanik organic matter was deposited in reducing environments. Mass chromatograms show the distribution of regular steranes, iso-steranes, lower molecular weight C21 and C22 steranes (pregnanes) (m/z 217) and triterpanes (m/z 191). The biomarkers distribution of the domanic samples generally suggests a major marine phytoplankton contribution relative to terrigenous land plant source input. The marine affinity is evident from the relatively abundant C27 steranes, which are biomarkers for marine algal contribution to organic matter and low C29 sterane contens. In this present study, samples are dominated by 5α, 14α, 17α (H)-20R and 5β, 14α, 17α (H)-20R steranes (biological configuration). The ratios of 20S/(20S+20R) for αααC29 steranes and ββ/(αα + ββ) for 5α-C29 steranes in the samples, are 0.21 to 0.55 and to 0.12 to 0.50, respectively. The thermal maturity level, assessed by values of several biomarker parameters has been estimated to be within end of diagenesis/eginning of catagenesis and correspond to theoretical vitrinite values (R0) in the range 0.57-0.65%.

Confirming Pseudomonas putida as a reliable bioassay for demonstrating biocompatibility enhancement by solar photo-oxidative processes of a biorecalcitrant effluent.

PubMed

García-Ripoll, A; Amat, A M; Arques, A; Vicente, R; Ballesteros Martín, M M; Pérez, J A Sánchez; Oller, I; Malato, S

2009-03-15

Experiments based on Vibrio fischeri, activated sludge and Pseudomonas putida have been employed to check variation in the biocompatibility of an aqueous solution of a commercial pesticide, along solar photo-oxidative process (TiO(2) and Fenton reagent). Activated sludge-based experiments have demonstrated a complete detoxification of the solution, although important toxicity is still detected according to the more sensitive V. fischeri assays. In parallel, the biodegradability of organic matter is strongly enhanced, with BOD(5)/COD ratio above 0.8. Bioassays run with P. putida have given similar trends, remarking the convenience of using P. putida culture as a reliable and reproducible method for assessing both toxicity and biodegradability, as a substitute to other more time consuming methods.

40 CFR 265.1084 - Waste determination procedures.

Code of Federal Regulations, 2011 CFR

2011-07-01

... biodegradation efficiency (Rbio) for a treated hazardous waste. (i) The fraction of organics biodegraded (Fbio... biodegradation efficiency, percent. Fbio = Fraction of organic biodegraded as determined in accordance with the... biodegradation rate (MRbio) for a treated hazardous waste. (i) The MRbio shall be determined based on results for...

40 CFR 265.1084 - Waste determination procedures.

Code of Federal Regulations, 2013 CFR

2013-07-01

... biodegradation efficiency (Rbio) for a treated hazardous waste. (i) The fraction of organics biodegraded (Fbio... biodegradation efficiency, percent. Fbio = Fraction of organic biodegraded as determined in accordance with the... biodegradation rate (MRbio) for a treated hazardous waste. (i) The MRbio shall be determined based on results for...

40 CFR 265.1084 - Waste determination procedures.

Code of Federal Regulations, 2012 CFR

2012-07-01

... biodegradation efficiency (Rbio) for a treated hazardous waste. (i) The fraction of organics biodegraded (Fbio... biodegradation efficiency, percent. Fbio = Fraction of organic biodegraded as determined in accordance with the... biodegradation rate (MRbio) for a treated hazardous waste. (i) The MRbio shall be determined based on results for...

40 CFR 265.1084 - Waste determination procedures.

Code of Federal Regulations, 2010 CFR

2010-07-01

... biodegradation efficiency (Rbio) for a treated hazardous waste. (i) The fraction of organics biodegraded (Fbio... biodegradation efficiency, percent. Fbio = Fraction of organic biodegraded as determined in accordance with the... biodegradation rate (MRbio) for a treated hazardous waste. (i) The MRbio shall be determined based on results for...

Estimating the Concentration and Biodegradability of Organic Matter in 22 Wastewater Treatment Plants Using Fluorescence Excitation Emission Matrices and Parallel Factor Analysis

PubMed Central

Yang, Liyang; Shin, Hyun-Sang; Hur, Jin

2014-01-01

This study aimed at monitoring the changes of fluorescent components in wastewater samples from 22 Korean biological wastewater treatment plants and exploring their prediction capabilities for total organic carbon (TOC), dissolved organic carbon (DOC), biochemical oxygen demand (BOD), chemical oxygen demand (COD), and the biodegradability of the wastewater using an optical sensing technique based on fluorescence excitation emission matrices and parallel factor analysis (EEM-PARAFAC). Three fluorescent components were identified from the samples by using EEM-PARAFAC, including protein-like (C1), fulvic-like (C2) and humic-like (C3) components. C1 showed the highest removal efficiencies for all the treatment types investigated here (69% ± 26%–81% ± 8%), followed by C2 (37% ± 27%–65% ± 35%), while humic-like component (i.e., C3) tended to be accumulated during the biological treatment processes. The percentage of C1 in total fluorescence (%C1) decreased from 54% ± 8% in the influents to 28% ± 8% in the effluents, while those of C2 and C3 (%C2 and %C3) increased from 43% ± 6% to 62% ± 9% and from 3% ± 7% to 10% ± 8%, respectively. The concentrations of TOC, DOC, BOD, and COD were the most correlated with the fluorescence intensity (Fmax) of C1 (r = 0.790–0.817), as compared with the other two fluorescent components. The prediction capability of C1 for TOC, BOD, and COD were improved by using multiple regression based on Fmax of C1 and suspended solids (SS) (r = 0.856–0.865), both of which can be easily monitored in situ. The biodegradability of organic matter in BOD/COD were significantly correlated with each PARAFAC component and their combinations (r = −0.598–0.613, p < 0.001), with the highest correlation coefficient shown for %C1. The estimation capability was further enhanced by using multiple regressions based on %C1, %C2 and C3/C2 (r = −0.691). PMID:24448170

Determination of biodegradability kinetics of RCRA compounds using respirometry for structure-activity relationships

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

Tabak, H.H.; Desai, S.; Govind, R.

1990-01-01

Electrolytic respirometry is attaining prominence in biodegradation studies and is becoming one of the more suitable experimental methods for measuring the biodegradability and the kinetics of biodegradation of toxic organic compounds by the sewage, sludge, and soil microbiota and for determining substrate inhibitory effects to microorganisms in wastewater treatment systems. The purpose of the study was to obtain information on biological treatability of the benzene, phenol, phthalate, ketone organics and of the Superfund CERCLA organics bearing wastes in wastewater treatment systems which will support the development of an EPA technical guidance document on the discharge of the above organics tomore » POTWs. The paper discusses the experimental design and procedural steps for the respirometric biodegradation and toxicity testing approach for individual organics or specific industrial wastes at different concentration levels in a mineral salts medium. A developed multi-level protocol is presented for determination of the biodegradability, microbial acclimation to toxic substrates and first order kinetic parameters of biodegradation for estimation of the Monod kinetic parameter of toxic organic compounds, in order to correlate the extent and rate of biodegradation with a predictive model based on chemical properties and molecular structure of these compounds. Respirometric biodegradation/inhibition and biokinetic data are provided for representative RCRA alkyl benzene and ketone organics.« less

Biodegradability of fluorinated fire-fighting foams in water.

PubMed

Bourgeois, A; Bergendahl, J; Rangwala, A

2015-07-01

Fluorinated fire-fighting foams may be released into the environment during fire-fighting activities, raising concerns due to the potential environmental and health impacts for some fluorinated organics. The current study investigated (1) the biodegradability of three fluorinated fire-fighting foams, and (2) the applicability of current standard measures used to assess biodegradability of fluorinated fire-fighting foams. The biodegradability of three fluorinated fire-fighting foams was evaluated using a 28-day dissolved organic carbon (DOC) Die-Away Test. It was found that all three materials, diluted in water, achieved 77-96% biodegradability, meeting the criteria for "ready biodegradability". Defluorination of the fluorinated organics in the foam during biodegradation was measured using ion chromatography. It was found that the fluorine liberated was 1-2 orders of magnitude less than the estimated initial amount, indicating incomplete degradation of fluorinated organics, and incomplete CF bond breakage. Published biodegradability data may utilize biochemical oxygen demand (BOD), chemical oxygen demand (COD), and total organic carbon (TOC) metrics to quantify organics. COD and TOC of four fluorinated compounds were measured and compared to the calculated carbon content or theoretical oxygen demand. It was found that the standard dichromate-based COD test did not provide an accurate measure of fluorinated organic content. Thus published biodegradability data using COD for fluorinated organics quantification must be critically evaluated for validity. The TOC measurements correlated to an average of 91% of carbon content for the four fluorinated test substances, and TOC is recommended for use as an analytical parameter in fluorinated organics biodegradability tests. Copyright © 2015 Elsevier Ltd. All rights reserved.

Environmental nanoparticles are significantly over-expressed in acute myeloid leukemia.

PubMed

Visani, G; Manti, A; Valentini, L; Canonico, B; Loscocco, F; Isidori, A; Gabucci, E; Gobbi, P; Montanari, S; Rocchi, M; Papa, S; Gatti, A M

2016-11-01

The increase in the incidence of acute myeloid leukemia (AML) may suggest a possible environmental etiology. PM2.5 was declared by IARC a Class I carcinogen. No report has focused on particulate environmental pollution together with AML. The study investigated the presence and composition of particulate matter in blood with a Scanning Electron Microscope coupled with an Energy Dispersive Spectroscope, a sensor capable of identifying the composition of foreign bodies. 38 peripheral blood samples, 19 AML cases and 19 healthy controls, were analyzed. A significant overload of particulate matter-derived nanoparticles linked or aggregated to blood components was found in AML patients, while almost absent in matched healthy controls. Two-tailed Student's t-test, MANOVA and Principal Component Analysis indicated that the total numbers of aggregates and particles were statistically different between cases and controls (MANOVA, P<0.001 and P=0.009 respectively). The particles detected showed to contain highly-reactive, non-biocompatible and non-biodegradable metals; in particular, micro- and nano-sized particles grouped in organic/inorganic clusters, with statistically higher frequency of a subgroup of elements in AML samples. The demonstration, for the first time, of an overload of nanoparticles linked to blood components in AML patients could be the basis for a possible, novel pathogenetic mechanism for AML development. Copyright © 2016 Elsevier Ltd. All rights reserved.

Eco-Friendly and Biodegradable Biopolymer Chitosan/Y₂O₃ Composite Materials in Flexible Organic Thin-Film Transistors.

PubMed

Du, Bo-Wei; Hu, Shao-Ying; Singh, Ranjodh; Tsai, Tsung-Tso; Lin, Ching-Chang; Ko, Fu-Hsiang

2017-09-03

The waste from semiconductor manufacturing processes causes serious pollution to the environment. In this work, a non-toxic material was developed under room temperature conditions for the fabrication of green electronics. Flexible organic thin-film transistors (OTFTs) on plastic substrates are increasingly in demand due to their high visible transmission and small size for use as displays and wearable devices. This work investigates and analyzes the structured formation of aqueous solutions of the non-toxic and biodegradable biopolymer, chitosan, blended with high-k-value, non-toxic, and biocompatible Y₂O₃ nanoparticles. Chitosan thin films blended with Y₂O₃ nanoparticles were adopted as the gate dielectric thin film in OTFTs, and an improvement in the dielectric properties and pinholes was observed. Meanwhile, the on/off current ratio was increased by 100 times, and a low leakage current was observed. In general, the blended chitosan/Y₂O₃ thin films used as the gate dielectric of OTFTs are non-toxic, environmentally friendly, and operate at low voltages. These OTFTs can be used on surfaces with different curvature radii because of their flexibility.

Insight into the composition and degradation potential of dissolved organic matter with different hydrophobicity in landfill leachates.

PubMed

He, Xiao-Song; Xi, Bei-Dou; Gao, Ru-Tai; Zhang, Hui; Dang, Qiu-Ling; Li, Dan; Huang, Cai-Hong

2016-02-01

Dissolved organic matter (DOM) isolated from the leachates with different landfill ages was fractionated into hydrophobic acid (HOA), hydrophobic neutral (HON), hydrophobic base (HOB) fractions and hydrophilic matter (HIM) based on hydrophobicity, and the composition and degradation potential of the bulk DOM and its fractions were investigated by excitation-emission matrix fluorescence spectra coupled with parallel factor analysis. Results showed that the bulk DOM comprised fulvic-, humic-, tryptophan- and tyrosine-like substances, as well as component C1, whose composition and origin was unidentified. Landfill process increased the content of component C1, fulvic- and humic-like matter. The HON fractions comprised primarily component C1 and tyrosine-like matter. The HOA, HOB and HIM fractions isolated from the young leachates consisted mainly of tryptophan- and tyrosine-like substances. As to the intermediate and old leachates, the HOA and HOB fractions comprised mainly component C1, while the HIM comprised mainly fulvic-like matter. The HIM showed the most resistant against biodegradation among the four fractions, and was the main component of leachate treatment. Advanced oxidation and/or membrane treatment are recommended to remove the HIM fraction due to its hydrophilic and stable characteristics. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effect of compost and biodegradable chelate addition on phytoextraction of copper by Oenothera picensis grown in Cu-contaminated acid soils.

PubMed

González, Isabel; Neaman, Alexander; Cortés, Amparo; Rubio, Patricio

2014-01-01

Oenothera picensis plants (Fragrant Evening Primrose) grow in the acid soils contaminated by Cu smelting in the coastal region of central Chile. We evaluated the effects of compost, at application rate of 5 kg m(-2), and biodegradable chelate MGDA (methylglycinediacetic acid), at application rate of 6 mmol plant(-1), on Cu phytoextraction by O. picensis, in field plots. No significant differences were found between treatments regarding aboveground biomass, shoot Cu concentrations and Cu phytoextraction of O. picensis. This lack of effects of the treatments was provoked by the large variability of soil properties, prior to applying of the treatments. The shoot Cu concentration in O. picensis positively and significantly correlated to exchangeable Cu concentration in the soil. Likewise, the aboveground biomass of O. picensis positively and significantly correlated to soil organic matter content. The Cu phytoextraction by O. picensis, in turn, positively and significantly correlated to both variables, i.e. exchangeable Cu concentration and organic matter content. The average Cu phytoextraction was 1.1 mg plant(-1), which is equivalent to 90 g ha(-1) at planting rate of 8 plants m(-2). In the chelate treatment, Cu phytoextraction was 2.6±2.1 mg plant(-1), which is equivalent to 212±171 g ha(-1) at planting rate of 8 plants m(-2). Copyright © 2013 Elsevier Ltd. All rights reserved.

Evaluation of the simultaneous removal of recalcitrant drugs (bezafibrate, gemfibrozil, indomethacin and sulfamethoxazole) and biodegradable organic matter from synthetic wastewater by electro-oxidation coupled with a biological system.

PubMed

Rodríguez-Nava, Odín; Ramírez-Saad, Hugo; Loera, Octavio; González, Ignacio

2016-12-01

Pharmaceutical degradation in conventional wastewater treatment plants (WWTP) represents a challenge since municipal wastewater and hospital effluents contain pharmaceuticals in low concentrations (recalcitrant and persistent in WWTP) and biodegradable organic matter (BOM) is the main pollutant. This work shows the feasibility of coupling electro-oxidation with a biological system for the simultaneous removal of recalcitrant drugs (bezafibrate, gemfibrozil, indomethacin and sulfamethoxazole (BGIS)) and BOM from wastewater. High removal efficiencies were attained without affecting the performance of activated sludge. BGIS degradation was performed by advanced electrochemical oxidation and the activated sludge process for BOM degradation in a continuous reactor. The selected electrochemical parameters from microelectrolysis tests (1.2 L s(-1) and 1.56 mA cm(-2)) were maintained to operate a filter press laboratory reactor FM01-LC using boron-doped diamond as the anode. The low current density was chosen in order to remove drugs without decreasing BOM and chlorine concentration control, so as to avoid bulking formation in the biological process. The wastewater previously treated by FM01-LC was fed directly (without chemical modification) to the activated sludge reactor to remove 100% of BGIS and 83% of BOM; conversely, the BGIS contained in wastewater without electrochemical pre-treatment were persistent in the biological process and promoted bulking formation.

Fate and behavior of dissolved organic matter in a submerged anoxic-aerobic membrane bioreactor (MBR).

PubMed

Zhang, Dongqing; Trzcinski, Antoine Prandota; Luo, Jinxue; Stuckey, David C; Tan, Soon Keat

2018-02-01

In this study, the production, composition, and characteristics of dissolved organic matter (DOM) in an anoxic-aerobic submerged membrane bioreactor (MBR) were investigated. The average concentrations of proteins and carbohydrates in the MBR aerobic stage were 3.96 ± 0.28 and 8.36 ± 0.89 mg/L, respectively. After membrane filtration, these values decreased to 2.9 ± 0.2 and 2.8 ± 0.2 mg/L, respectively. High performance size exclusion chromatograph (HP-SEC) analysis indicated a bimodal molecular weight (MW) distribution of DOMs, and that the intensities of all the peaks were reduced in the MBR effluent compared to the influent. Three-dimensional fluorescence excitation emission matrix (FEEM) indicated that fulvic and humic acid-like substances were the predominant DOMs in biological treatment processes. Precise identification and characterization of low-MW DOMs was carried out using gas chromatography-mass spectrometry (GC-MS). The GC-MS analysis indicated that the highest peak numbers (170) were found in the anoxic stage, and 54 (32%) compounds were identified with a similarity greater than 80%. Alkanes (28), esters (11), and aromatics (7) were the main compounds detected. DOMs exhibited both biodegradable and recalcitrant characteristics. There were noticeable differences in the low-MW DOMs present down the treatment process train in terms of numbers, concentrations, molecular weight, biodegradability, and recalcitrance.

Biodegradation of plastics: current scenario and future prospects for environmental safety.

PubMed

Ahmed, Temoor; Shahid, Muhammad; Azeem, Farrukh; Rasul, Ijaz; Shah, Asad Ali; Noman, Muhammad; Hameed, Amir; Manzoor, Natasha; Manzoor, Irfan; Muhammad, Sher

2018-03-01

Plastic is a general term used for a wide range of high molecular weight organic polymers obtained mostly from the various hydrocarbon and petroleum derivatives. There is an ever-increasing trend towards the production and consumption of plastics due to their extensive industrial and domestic applications. However, a wide spectrum of these polymers is non-biodegradable with few exceptions. The extensive use of plastics, lack of waste management, and casual community behavior towards their proper disposal pose a significant threat to the environment. This has raised growing concerns among various stakeholders to devise policies and innovative strategies for plastic waste management, use of biodegradable polymers especially in packaging, and educating people for their proper disposal. Current polymer degradation strategies rely on chemical, thermal, photo, and biological procedures. In the presence of proper waste management strategies coupled with industrially controlled biodegradation facilities, the use of biodegradable plastics for some applications such as packaging or health industry is a promising and attractive option for economic, environmental, and health benefits. This review highlights the classification of plastics with special emphasis on biodegradable plastics and their rational use, the identified mechanisms of plastic biodegradation, the microorganisms involved in biodegradation, and the current insights into the research on biodegradable plastics. The review has also identified the research gaps in plastic biodegradation followed by future research directions.

Selective simplification and reinforcement of microbial community in autothermal thermophilic aerobic digestion to enhancing stabilization process of sewage sludge by conditioning with ferric nitrate.

PubMed

Jin, Ningben; Shou, Zongqi; Yuan, Haiping; Lou, Ziyang; Zhu, Nanwen

2016-03-01

The effect of ferric nitrate on microbial community and enhancement of stabilization process for sewage sludge was investigated in autothermal thermophilic aerobic digestion. The disinhibition of volatile fatty acids (VFA) was obtained with alteration of individual VFA concentration order. Bacterial taxonomic identification by 454 high-throughput pyrosequencing found the dominant phylum Proteobacteria in non-dosing group was converted to phylum Firmicutes in dosing group after ferric nitrate added and simplification of bacteria phylotypes was achieved. The preponderant Tepidiphilus sp. vanished, and Symbiobacterium sp. and Tepidimicrobium sp. were the most advantageous phylotypes with conditioning of ferric nitrate. Consequently, biodegradable substances in dissolved organic matters increased, which contributed to the favorable environment for microbial metabolism and resulted in acceleration of sludge stabilization. Ultimately, higher stabilization level was achieved as ratio of soluble chemical oxygen demand to total chemical oxygen demand (TCOD) decreased while TCOD reduced as well in dosing group comparing to non-dosing group. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of oxidized leachate on degradation of lignin by sulfate-reducing bacteria.

PubMed

Kim, Jong-Ho; Kim, Moonil; Bae, Wooken

2009-08-01

Municipal solid waste materials (MSWs) in landfills need a long period of stabilization because lignin compounds in MSWs and leachate are not readily biodegraded, but inhibit methanogenic metabolism. Recirculation of leachate into the landfill offers the potential advantage of increasing the rate of decomposition of organic matter. However, the degradation of lignin by leachate recirculation alone is quite difficult. Several recent studies have demonstrated that sulfate-reducing bacteria (SRB) were able to degrade lignin compounds. In this study, batch tests were conducted to investigate the impacts of SRB enrichment on lignin decomposition rates as well as the decomposition of other biodegradable organics. Further, the effects of nitrite and nitrate on lignin degradation rates were also studied. A 16S rRNA assay showed that the SRB used herein, which were obtained by enriching solid waste collected from a closed MSW landfill, were Thaurea sp. and Desulfovibrio sp. Lignin was found to be biodegraded by the SRB and the rate of lignin removal per unit of waste volatile suspended solid was 2.9 mg lignin g(-1) VSS day(- 1). It was found that the initial degradation rate increased under higher initial lignin concentrations. However, the degradation rate during days 6-19 became slower than that during the initial 9 days because lignin consisted of complexly bonded aromatic compounds that were not readily biodegradable. Adding other organics such as lactate seemed to improve the rate and amount of lignin degradation, probably due to the increase in SRB associated with consumption of the additional organics. The lignin removal percentage decreased with increases in oxidized nitrogen (nitrite or nitrate) concentrations, indicating that oxidized nitrogen could inhibit SRB activity. Conclusively, the study verified the existence of SRB in the landfill and showed that the SRB could be activated for the degradation of lignin by the recirculation of the leachate, which is consistent with other studies showing that leachate recirculation could shorten the stabilization period of the landfill.

Dynamics of dissolved organic carbon (DOC) through stormwater basins designed for groundwater recharge in urban area: Assessment of retention efficiency.

PubMed

Mermillod-Blondin, Florian; Simon, Laurent; Maazouzi, Chafik; Foulquier, Arnaud; Delolme, Cécile; Marmonier, Pierre

2015-09-15

Managed aquifer recharge (MAR) has been developed in many countries to limit the risk of urban flooding and compensate for reduced groundwater recharge in urban areas. The environmental performances of MAR systems like infiltration basins depend on the efficiency of soil and vadose zone to retain stormwater-derived contaminants. However, these performances need to be finely evaluated for stormwater-derived dissolved organic matter (DOM) that can affect groundwater quality. Therefore, this study examined the performance of MAR systems to process DOM during its transfer from infiltration basins to an urban aquifer. DOM characteristics (fluorescent spectroscopic properties, biodegradable and refractory fractions of dissolved organic carbon -DOC-, consumption by micro-organisms during incubation in slow filtration sediment columns) were measured in stormwater during its transfer through three infiltration basins during a stormwater event. DOC concentrations sharply decreased from surface to the aquifer for the three MAR sites. This pattern was largely due to the retention of biodegradable DOC which was more than 75% for the three MAR sites, whereas the retention of refractory DOC was more variable and globally less important (from 18% to 61% depending on MAR site). Slow filtration column experiments also showed that DOC retention during stormwater infiltration through soil and vadose zone was mainly due to aerobic microbial consumption of the biodegradable fraction of DOC. In parallel, measurements of DOM characteristics from groundwaters influenced or not by MAR demonstrated that stormwater infiltration increased DOC quantity without affecting its quality (% of biodegradable DOC and relative aromatic carbon content -estimated by SUVA254-). The present study demonstrated that processes occurring in soil and vadose zone of MAR sites were enough efficient to limit DOC fluxes to the aquifer. Nevertheless, the enrichments of DOC concentrations measured in groundwater below infiltration basins need to be considered in future studies to especially assess their impact on groundwater quality. Copyright © 2015 Elsevier Ltd. All rights reserved.

Release and microbial degradation of dissolved organic matter (DOM) from the macroalgae Ulva prolifera.

PubMed

Zhang, Tao; Wang, Xuchen

2017-12-15

Release and microbial degradation of dissolved organic matter (DOM) and chromophoric dissolved organic matter (CDOM) from the macroalgae Ulva prolifera were studied in laboratory incubation experiments. The release of DOM and CDOM from Ulva prolifera was a rapid process, and hydrolysis played an important role in the initial leaching of the organic compounds from the algae. Bacterial activity enhanced the release of DOM and CDOM during degradation of the algae and utilization of the released organic compounds. It is calculated that 43±2% of the C and 63±3% of the N from Ulva prolifera's biomass were released during the 20-day incubation, and 65±3% of the released C and 87±4% of the released N were utilized by bacteria. In comparison, only 18±1% of the algae's C and 17±1% of its N were released when bacterial activities were inhibited. The fluorescence characteristics of the CDOM indicate that protein-like DOM was the major organic component released from Ulva prolifera that was highly labile and biodegradable. Bacteria played an important role in regulating the chemical composition and fluorescence characteristics of the DOM. Our study suggests that the release of DOM from Ulva prolifera provides not only major sources of organic C and N, but also important food sources to microbial communities in coastal waters. Copyright © 2017 Elsevier Ltd. All rights reserved.

Impact of biological activated carbon pre-treatment on the hydrophilic fraction of effluent organic matter for mitigating fouling in microfiltration.

PubMed

Pramanik, Biplob Kumar; Roddick, Felicity A; Fan, Linhua

2017-07-24

The hydrophilic (HPI) fraction of effluent organic matter, which has protein and carbohydrate contents, has a high propensity to foul low-pressure membranes. Biological activated carbon (BAC) filtration was examined as a pre-treatment for reducing the fouling of a microfiltration (MF) membrane (0.1 µm PVDF) by the HPI organic fraction extracted from a biologically treated secondary effluent (BTSE). Although the BAC removed less dissolved organic carbon, carbohydrate and protein from the HPI fraction than the granular activated carbon treatment which was used for comparison, it led to better improvement in permeate flux. This was shown to be due to the removal/breakdown of the HPI fraction resulting in less deposition of these organics on the membrane, many components of which are high molecular weight biopolymers (such as protein and carbohydrate molecules) through biodegradation and adsorption of those molecules on the biofilm and activated carbon. This study established the potential of BAC pre-treatment for reducing the HPI fouling of the membrane and thus improving the performance for the MF of BTSE for water reclamation.

Organic matter and modeling redox reactions during river bank filtration in an alluvial aquifer of the Lot River, France.

PubMed

Kedziorek, Monika A M; Geoffriau, Stephane; Bourg, Alain C M

2008-04-15

A 3 year study of the infiltration of Lot River water into a well field located in an adjacent gravel and clay alluvial aquifer was conducted to assess the importance of organic matter regarding the redox processes which influence groundwater quality in a positive (denitrification) or negative (Mn dissolution) manner. Chloride was used to quantify the mixing of river water with groundwater. According to modeling with PHREEQC, the biodegradation of the infiltrated dissolved organic carbon (DOCi) is not sufficient to explain the observed consequences of the redox reactions (dissolved O2 depletion, denitrification, Mn dissolution). Another electron donor source must therefore be involved: we propose solid organic carbon (SOC) as a likely candidate, if made available for degradation by prior hydrolysis. Its contribution to redox reactions could be significant (30-80% of the total organic carbon consumed by redox reactions during river bank filtration). We show here also that even though the first few meters of infiltration are highly reactive, significant redox reactions can take place further in the aquifer, possibly affecting groundwater quality away from the river bank.

Reclaimed wastewater quality enhancement by oxygen injection during transportation.

PubMed

Rodríguez-Gómez, L E; Alvarez, M; Rodríguez-Sevilla, J; Marrero, M C; Hernández, A

2011-01-01

In-sewer treatments have been studied in sewer systems, but few have been carried out on reclaimed wastewater systems. A study of oxygen injection has been performed in a completely filled gravity pipe, 0.6 m in diameter and 62 km long, in cast iron with concrete inside coating, which is part of the reclaimed wastewater reuse scheme of Tenerife (Spain). A high pressure oxygen injection system was installed at 16.0 km from pipe inlet and a constant dosage of 30 mg/L O(2) has been injected during six months, under three different operational modes (low COD, 63 mg/L; high COD, 91 mg/L; and partially nitrified water). Oxygen has been consumed in nitrification and organic matter reduction. Generally, nitrification is clearly favored instead of the organic matter oxidation. Nitrification occurs, in general, with nitrite accumulation due to the presence of free ammonia above 1 mg/L. Denitrification is in all cases incomplete due to a limitation of easily biodegradable organic matter content, inhibiting the appearance of anaerobic conditions and sulfide generation. A notable reduction of organic matter parameters is achieved (TSS below 10 mg/L), which is significantly higher than that observed under the ordinary transport conditions without oxygen. This leads to a final cost reduction, and the oxygen injection system helps water reuse managers to maintain a final good water quality in the case of a treatment plant malfunction.

Environmental impact of rejected materials generated in organic fraction of municipal solid waste anaerobic digestion plants: Comparison of wet and dry process layout.

PubMed

Colazo, Ana-Belén; Sánchez, Antoni; Font, Xavier; Colón, Joan

2015-09-01

Anaerobic digestion of source separated organic fraction of municipal solid waste is an increasing waste valorization alternative instead of incineration or landfilling of untreated biodegradable wastes. Nevertheless, a significant portion of biodegradable wastes entering the plant is lost in pre-treatments and post-treatments of anaerobic digestion facilities together with other improper materials such as plastics, paper, textile materials and metals. The rejected materials lost in these stages have two main implications: (i) less organic material enters to digesters and, as a consequence, there is a loss of biogas production and (ii) the rejected materials end up in landfills or incinerators contributing to environmental impacts such as global warming or eutrophication. The main goals of this study are (i) to estimate potential losses of biogas in the rejected solid materials generated during the pre- and post-treatments of two full-scale anaerobic digestion facilities and (ii) to evaluate the environmental burdens associated to the final disposal (landfill or incineration) of these rejected materials by means of Life Cycle Assessment. This study shows that there is a lost of potential biogas production, ranging from 8% to 15%, due to the loss of organic matter during pre-treatment stages in anaerobic digestion facilities. From an environmental point of view, the Life Cycle Assessment shows that the incineration scenario is the most favorable alternative for eight out of nine impact categories compared with the landfill scenario. The studied impact categories are Climate Change, Fossil depletion, Freshwater eutrophication, Marine eutrophication, Ozone depletion, Particulate matter formation, Photochemical oxidant formation, Terrestrial acidification and Water depletion. Copyright © 2015 Elsevier Ltd. All rights reserved.

Influences of NOM composition and bacteriological characteristics on biological stability in a full-scale drinking water treatment plant.

PubMed

Park, Ji Won; Kim, Hyun-Chul; Meyer, Anne S; Kim, Sungpyo; Maeng, Sung Kyu

2016-10-01

The influences of natural organic matter (NOM) and bacteriological characteristics on the biological stability of water were investigated in a full-scale drinking water treatment plant. We found that prechlorination decreased the hydrophobicity of the organic matter and significantly increased the high-molecular-weight (MW) dissolved organic matter, such as biopolymers and humic substances. High-MW organic matter and structurally complex compounds are known to be relatively slowly biodegradable; however, because of the prechlorination step, the indigenous bacteria could readily utilise these fractions as assimilable organic carbon. Sequential coagulation and sedimentation resulted in the substantial removal of biopolymer (74%), humic substance (33%), bacterial cells (79%), and assimilable organic carbon (67%). Rapid sand and granular activated carbon filtration induced an increase in the low-nucleic-acid content bacteria; however, these bacteria were biologically less active in relation to enzymatic activity and ATP. The granular activated carbon step was essential to securing biological stability (the ability to prevent bacterial growth) by removing the residual assimilable organic carbon that had formed during the ozone treatment. The growth potential of Escherichia coli and indigenous bacteria were found to differ in respect to NOM characteristics. In comparison with E. coli, the indigenous bacteria utilised a broader range of NOM as a carbon source. Principal component analysis demonstrated that the measured biological stability of water could differ, depending on the NOM characteristics, as well as on the bacterial inoculum selected for the analysis. Copyright © 2016 Elsevier Ltd. All rights reserved.

Fluorescence spectroscopy reveals accompanying occurrence of ammonium with fulvic acid-like organic matter in a fluvio-lacustrine aquifer of Jianhan Plain.

PubMed

Huang, Shuangbing; Wang, Yanxin; Ma, Teng; Wang, Yanyan; Zhao, Long

2016-05-01

This study is the first to investigate the simultaneous presence of NH4 (+) and fluorescent organic matter components (FOCs) from a fluvio-lacustrine aquifer in Central Jianghan Plain. Sediment, groundwater, and surface water samples were collected for the sediment organic matter extraction, 3D fluorescence spectroscopy characterization, and/or hydrochemical analysis. NH4 (+) and dissolved organic carbon was ubiquitous in the groundwater. The fluorescence spectroscopy revealed good relationships between NH4 (+) and fulvic acid-like components (FALCs) in the groundwater and sediment-extracted organic matter (SEOM) solutions. NH4 (+) also exhibited significant positive correlation with protein-like component (PLC) (p < 0.001), with the stronger in the SEOM solutions than that in groundwater. Comparisons of spectroscopic indices [e.g., humification index (HIX), biological index (BIX), spectra slope (S275-295), and specific UV absorbance (SUVA254)] between the groundwater and SEOM solutions revealed more labile properties of SEOM. This result indicates that the decreasing NH4 (+)-FOCs correlations of groundwater relative to sediments may be attributed to microbial degradation. Factor analysis identifies important factors that cause NH4 (+) occurrence in the groundwater. The accompanying increase of FALC (C1) and NH4-N with the mole concentration of the normalized HCO3 (-)/(Ca(2+)+Mg(2+)) and [H(+)] suggests that couple effects of various biodegradations simultaneously occur in the aquifer, promoting the occurrence of NH4-DOMs.

Thermochemical pretreatments of organic fraction of municipal solid waste from a mechanical-biological treatment plant.

PubMed

Álvarez-Gallego, Carlos José; Fdez-Güelfo, Luis Alberto; de los Ángeles Romero Aguilar, María; Romero García, Luis Isidoro

2015-02-09

The organic fraction of municipal solid waste (OFMSW) usually contains high lignocellulosic and fatty fractions. These fractions are well-known to be a hard biodegradable substrate for biological treatments and its presence involves limitations on the performance of anaerobic processes. To avoid this, thermochemical pretreatments have been applied on the OFMSW coming from a full-scale mechanical-biological treatment (MBT) plant, in order to pre-hydrolyze the waste and improve the organic matter solubilisation. To study the solubilisation yield, the increments of soluble organic matter have been measured in terms of dissolved organic carbon (DOC), soluble chemical oxygen demand (sCOD), total volatile fatty acids (TVFA) and acidogenic substrate as carbon (ASC). The process variables analyzed were temperature, pressure and NaOH dosage. The levels of work for each variable were three: 160-180-200 °C, 3.5-5.0-6.5 bar and 2-3-4 g NaOH/L. In addition, the pretreatment time was also modified among 15 and 120 min. The best conditions for organic matter solubilisation were 160 °C, 3 g NaOH/L, 6.5 bar and 30 min, with yields in terms of DOC, sCOD, TVFA and ASC of 176%, 123%, 119% and 178% respectively. Thus, predictably the application of this pretreatment in these optimum conditions could improve the H2 production during the subsequent Dark Fermentation process.

Oxytetracycline removal from water by novel microbial embedding gel beads

NASA Astrophysics Data System (ADS)

Wu, Nan; Pan, Peng; Zeng, Ming; Wang, Wei; Xu, Chenshan; Zhang, Zongpeng; Liu, Xinyuan; Wang, Yichao

2018-01-01

As a common antibiotic in aquatic environment, excessive oxytetracycline (OTC) is urgent to be removed due to its great biological toxicity. Compared with the traditional activated sludge, microbial embedding can enhance the treating efficiency. In this study, novel microbial embedding gel beads were produced with the additional agent of cyclodextrin (CD). Results show that CD could increase the mass transfer of OTC into gel beads, possibly because of its strong affinity for organic matters. In terms of OTC biodegradation, gel beads with CD were comparable to gel beads without CD, while the former’s sucrose removal efficiency was higher than the latter. The biodegradation of OTC only occurred in the presence of sucrose. The respiration test also confirmed these findings. Overall, the produced novel gel beads modified with CD could improve the removal performance of OTC.

Combined treatment of mezcal vinasses by ozonation and activated sludge.

PubMed

2017-10-18

In Mexico, mezcal production generates huge amounts of vinasses (MV) that cause negative environmental impacts. Thus, MV treatment is necessary before discharge to water bodies. Although there is no information for mezcal vinasses, similar effluents have been treated by biological processes (i.e. anaerobic and aerobic) usually complemented by oxidative chemical pretreatments (ozonation) and physico-chemical methods. In this work MV were first ozonated and followed by batch aerobic biological degradation. In the ozonation stage, organic matter removals were 4.5-11 % as COD, whereas the removal of aromatic compounds and phenols were 16-32 % and 48-83 % respectively. In the aerobic post-treatment, COD depletions up to 85 % were achieved; removals in ozone pre-treated vinasses were higher (80 to 85 %) than that of raw vinasse (69 %). It seems that ozonation preferentially attacked the recalcitrant fraction of organic matter present in the vinasses and increased its aerobic biodegradability.

Sorption and biodegradation characteristics of the selected pharmaceuticals and personal care products onto tropical soil.

PubMed

Foolad, Mahsa; Hu, Jiangyong; Tran, Ngoc Han; Ong, Say Leong

2016-01-01

In the present study, the sorption and biodegradation characteristics of five pharmaceutical and personal care products (PPCPs), including acetaminophen (ACT), carbamazepine (CBZ), crotamiton (CTMT), diethyltoluamide (DEET) and salicylic acid (SA), were studied in laboratory-batch experiments. Sorption kinetics experimental data showed that sorption systems under this study were more appropriately described by the pseudo second-order kinetics with a correlation coefficient (R2)>0.98. Sorption equilibrium data of almost all target compounds onto soil could be better described by the Freundlich sorption isotherm model. The adsorption results showed higher soil affinity for SA, following by ACT. Results also indicated a slight effect of pH on PPCP adsorption with lower pH causing lower adsorption of compounds onto the soil except for SA at pH 12. Moreover, adsorption of PPCPs onto the soil was influenced by natural organic matter (NOM) since the higher amount of NOM caused lower adsorption to the soil. Biodegradation studies of selected PPCPs by indigenous microbial community present in soil appeared that the removal rates of ACT, SA and DEET increased with time while no effect had been observed for the rest. This study suggests that the CBZ and CTMT can be considered as suitable chemical sewage indicators based on their low sorption affinity and high resistance to biodegradation.

Rates of As and trace-element mobilization caused by Fe reduction in mixed BTEX–ethanol experimental plumes

USGS Publications Warehouse

Ziegler, Brady A.; McGuire, Jennifer T.; Cozzarelli, Isabelle M.

2015-01-01

Biodegradation of organic matter, including petroleum-based fuels and biofuels, can create undesired secondary water-quality effects. Trace elements, especially arsenic (As), have strong adsorption affinities for Fe(III) (oxyhydr)-oxides and can be released to groundwater during Fe-reducing biodegradation. We investigated the mobilization of naturally occurring As, cobalt (Co), chromium (Cr), and nickel (Ni) from wetland sediments caused by the introduction of benzene, toluene, ethylbenzene, and xylenes (BTEX) and ethanol mixtures under iron- and nitrate-reducing conditions, using in situ push–pull tests. When BTEX alone was added, results showed simultaneous onset and similar rates of Fe reduction and As mobilization. In the presence of ethanol, the maximum rates of As release and Fe reduction were higher, the time to onset of reaction was decreased, and the rates occurred in multiple stages that reflected additional processes. The concentration of As increased from <1 μg/L to a maximum of 99 μg/L, exceeding the 10 μg/L limit for drinking water. Mobilization of Co, Cr, and Ni was observed in association with ethanol biodegradation but not with BTEX. These results demonstrate the potential for trace-element contamination of drinking water during biodegradation and highlight the importance of monitoring trace elements at natural and enhanced attenuation sites.

Linking optical properties of dissolved organic matter to multiple processes at the coastal plume zone in the East China Sea.

PubMed

Jiang, Yulin; Zhao, Jianfu; Li, Penghui; Huang, Qinghui

2016-10-12

Because of the significance in photosynthesis, nutrient dynamics, trophodynamics and biological activity, dissolved organic matter (DOM) is important to the microbial community in the coastal plume zone. In this study, we investigated the hydrodynamic processes, photodegradation and biodegradation of DOM at the Yangtze River plume in the East China Sea through analyzing water quality and optical properties of DOM. Surface water samples were collected to examine water quality and fluorescence properties of fluorescent dissolved organic matter (FDOM). The results indicated that dilution was the key factor in the multiple processes, and the mixing process gradually increased from nearshore to offshore in coastal water. Four components of FDOM representing humic-like substances (C1 & C4) and protein-like substances (C2 & C3) were identified, and all components showed nearly conservative behaviors. Protein-like substances were more mutable compared to humic-like substances. The photodegradation of humic-like substances caused brown algae blooms to some extent. The molecular weight of humic substances gradually decreased along the mixing process. FDOM in the plume zone was both of terrigenous and autochthonous origins, and the characteristic of terrigenous origin was obvious compared to that of autochthonous origin.

Gone or just out of sight? The apparent disappearance of aromatic litter components in soils

NASA Astrophysics Data System (ADS)

Klotzbücher, Thimo; Kalbitz, Karsten; Cerli, Chiara; Hernes, Peter J.; Kaiser, Klaus

2016-07-01

Uncertainties concerning stabilization of organic compounds in soil limit our basic understanding on soil organic matter (SOM) formation and our ability to model and manage effects of global change on SOM stocks. One controversially debated aspect is the contribution of aromatic litter components, such as lignin and tannins, to stable SOM forms. In the present opinion paper, we summarize and discuss the inconsistencies and propose research options to clear them. Lignin degradation takes place stepwise, starting with (i) depolymerization and followed by (ii) transformation of the water-soluble depolymerization products. The long-term fate of the depolymerization products and other soluble aromatics, e.g., tannins, in the mineral soils is still a mystery. Research on dissolved organic matter (DOM) composition and fluxes indicates dissolved aromatics are important precursors of stable SOM attached to mineral surfaces and persist in soils for centuries to millennia. Evidence comes from flux analyses in soil profiles, biodegradation assays, and sorption experiments. In contrast, studies on composition of mineral-associated SOM indicate the prevalence of non-aromatic microbial-derived compounds. Other studies suggest the turnover of lignin in soil can be faster than the turnover of bulk SOM. Mechanisms that can explain the apparent fast disappearance of lignin in mineral soils are, however, not yet identified. The contradictions might be explained by analytical problems. Commonly used methods probably detect only a fraction of the aromatics stored in the mineral soil. Careful data interpretation, critical assessment of analytical limitations, and combined studies on DOM and solid-phase SOM could thus be ways to unveil the issues.

Gone or just out of sight? The apparent disappearance of aromatic litter components in soils

NASA Astrophysics Data System (ADS)

Klotzbücher, Thimo; Kalbitz, Karsten; Cerli, Chiara; Hernes, Peter; Kaiser, Klaus

2016-04-01

Uncertainties concerning stabilization of organic compounds in soil limit our basic understanding on soil organic matter (SOM) formation and our ability to model and manage effects of global change on SOM stocks. One controversially debated aspect is the contribution of aromatic litter components, such as lignin and tannins, to stable SOM forms. Here we summarize and discuss the inconsistencies and propose research options to clear them. Lignin degradation takes place step-wise, starting with (i) depolymerisation, followed by (ii) transformation of the water-soluble depolymerization products. The long-term fate of the depolymerization products and other soluble aromatics, e.g., tannins, in the mineral soils is still a mystery. Research on dissolved organic matter (DOM) composition and fluxes indicates dissolved aromatics are important precursors of stable SOM attached to mineral surfaces and persist in soils for centuries to millennia. Evidence comes from flux analyses in soil profiles, biodegradation assays, and sorption experiments. In contrast, studies on composition of mineral-associated SOM indicate the prevalence of non-aromatic microbial-derived compounds. Other studies suggest the turnover of lignin in soil can be faster than the turnover of bulk SOM. Mechanisms that can explain the apparent fast disappearance of lignin in mineral soils are, however, not yet identified. The contradictions might be explained by analytical problems. Commonly used methods probably detect only a fraction of the aromatics stored in the mineral soil. Careful data interpretation, critical assessment of analytical limitations, and combined studies on DOM and solid-phase SOM could thus be ways to unveil the issues.

Low biodegradability of dissolved organic matter and trace metals from subarctic waters.

PubMed

Oleinikova, Olga V; Shirokova, Liudmila S; Drozdova, Olga Y; Lapitskiy, Sergey A; Pokrovsky, Oleg S

2018-03-15

The heterotrophic mineralization of dissolved organic matter (DOM) controls the CO 2 flux from the inland waters to the atmosphere, especially in the boreal waters, although the mechanisms of this process and the fate of trace metals associated with DOM remain poorly understood. We studied the interaction of culturable aquatic (Pseudomonas saponiphila) and soil (Pseudomonas aureofaciens) Gammaproteobacteria with seven different organic substrates collected in subarctic settings. These included peat leachate, pine crown throughfall, fen, humic lake, stream, river, and oligotrophic lake with variable dissolved organic carbon (DOC) concentrations (from 4 to 60mgL -1 ). The highest removal of DOC over 4days of reaction was observed in the presence of P. aureofaciens (33±5%, 43±3% and 53±7% of the initial amount in fen water, humic lake and stream, respectively). P. saponiphila degraded only 5% of DOC in fen water but did not affect all other substrates. Trace elements (TE) were essentially controlled by short-term (0-1h) adsorption on the surface of cells. Regardless of the nature of organic substrate and the identity of bacteria, the degree of adsorption ranged from 20 to 60% for iron (Fe 3+ ), 15 to 55% for aluminum (Al), 10 to 60% for manganese (Mn), 10 to 70% for nickel (Ni), 20 to 70% for copper (Cu), 10 to 60% for yttrium (Y), 30 to 80% for rare earth elements (REE), and 15 to 50% for uranium (U VI ). Rapid adsorption of organic and organo-mineral colloids on bacterial cell surfaces is novel and potentially important process, which deserves special investigation. The long-term removal of dissolved Fe and Al was generally consistent with solution supersaturation degree with respect to Fe and Al hydroxides, calculated by visual Minteq model. Overall, the biomass-normalized biodegradability of various allochthonous substrates by culturable bacteria is much lower than that of boreal DOM by natural microbial consortia. Copyright © 2017 Elsevier B.V. All rights reserved.

Revisiting the concept of recalcitrance and organic matter persistence in soils and aquatic systems: Does environment trump chemistry?

NASA Astrophysics Data System (ADS)

Marin-Spiotta, E.

2014-12-01

Most ecological models of decomposition rely on plant litter chemistry. However, growing evidence suggests that the chemical composition of organic matter (OM) is not a good predictor of its eventual fate in terrestrial or aquatic environments. New data on variable decomposition rates of select organic compounds challenge concepts of chemical recalcitrance, i.e. the inherent ability of certain molecular structures to resist biodegradation. The role of environmental or "ecosystem" properties on influencing decomposition dates back to some of the earliest research on soil OM. Despite early recognition that the physical and aqueous matrices are critical in determining the fate of organic compounds, the prevailing paradigm hinges on intrinsic chemical properties as principal predictors of decay rate. Here I build upon recent reviews and discuss new findings that contribute to three major transformations in our understanding of OM persistence: (1) a shift away from an emphasis on chemical recalcitrance as a primary predictor of turnover, (2) new interpretations of radiocarbon ages which challenge predictions of reactivity, and (3) the recognition that most detrital OM accumulating in soils and in water has been microbially processed. Predictions of OM persistence due to aromaticity are challenged by high variability in lignin and black C turnover observed in terrestrial and aquatic environments. Contradictions in the behavior of lignin are, in part, influenced by inconsistent methodologies among research communities. Even black C, long considered to be one of the most recalcitrant components of OM, is susceptible to biodegradation, challenging predictions of the stability of aromatic structures. At the same time, revised interpretations of radiocarbon data suggest that organic compounds can acquire long mean residence times by various mechanisms independent of their molecular structure. Understanding interactions between environmental conditions and biological reactivity can improve predictions of how disturbance events can further stabilize or destabilize organic C pools, with implications for terrestrial C storage, aquatic C cycling, and climate change.

The second green revolution? Production of plant-based biodegradable plastics.

PubMed

Mooney, Brian P

2009-03-01

Biodegradable plastics are those that can be completely degraded in landfills, composters or sewage treatment plants by the action of naturally occurring micro-organisms. Truly biodegradable plastics leave no toxic, visible or distinguishable residues following degradation. Their biodegradability contrasts sharply with most petroleum-based plastics, which are essentially indestructible in a biological context. Because of the ubiquitous use of petroleum-based plastics, their persistence in the environment and their fossil-fuel derivation, alternatives to these traditional plastics are being explored. Issues surrounding waste management of traditional and biodegradable polymers are discussed in the context of reducing environmental pressures and carbon footprints. The main thrust of the present review addresses the development of plant-based biodegradable polymers. Plants naturally produce numerous polymers, including rubber, starch, cellulose and storage proteins, all of which have been exploited for biodegradable plastic production. Bacterial bioreactors fed with renewable resources from plants--so-called 'white biotechnology'--have also been successful in producing biodegradable polymers. In addition to these methods of exploiting plant materials for biodegradable polymer production, the present review also addresses the advances in synthesizing novel polymers within transgenic plants, especially those in the polyhydroxyalkanoate class. Although there is a stigma associated with transgenic plants, especially food crops, plant-based biodegradable polymers, produced as value-added co-products, or, from marginal land (non-food), crops such as switchgrass (Panicum virgatum L.), have the potential to become viable alternatives to petroleum-based plastics and an environmentally benign and carbon-neutral source of polymers.

Assessment of toxicity and biodegradability on activated sludge of priority and emerging pollutants.

PubMed

Tobajas, Montserrat; Verdugo, Verónica; Polo, Alicia M; Rodriguez, Juan J; Mohedano, Angel F

2016-01-01

Several methods for evaluating the toxicity and biodegradability of hazardous pollutants (chlorinated compounds, chemical additives and pharmaceuticals) have been studied in this work. Different bioassays using representative bacteria of marine and terrestrial ecosystems such as Vibrio fischeri and Pseudomonas putida have been used to assess the ecotoxicity. Activated sludge was used to analyse the effect of those pollutants in a biological reactor of a sewage treatment plant (STP). The results demonstrate that none of the compounds is toxic to activated sludge, except ofloxacin to P. putida. The additives tested can be considered moderately toxic according to the more sensitive V. fischeri assays, whereas the EC50 values of the pharmaceuticals depend on the specific microorganism used in each test. Regarding the biodegradability, respirometric measurements were carried out for fast biodegradability assessment and the Zahn-Wellens test for inherent biodegradability. The evolution of the specific oxygen uptake rate (SOUR) showed that only diethyl phthalate was easily biodegradable and acetylsalicylic acid was partially biodegradable (98% and 65% degradation, respectively). The persistence of dichloromethane, ofloxacin and hidrochlorothiazide was confirmed along the 28 days of the Zahn-Wellens test whereas 1,1,1-trichloroethane showed inherent biodegradability (74% removal). Most of the chlorinated compounds, pharmaceuticals, bisphenol A and ethylenediaminetetraacetic acid were partially degraded in 28 d with total organic carbon (TOC) reduction ranging from 21% to 51%. Sulphamethoxazole showed certain biodegradation (50% removal) with TOC decrease around 31%, which indicates the formation of non-biodegradable by-products.

Recycling of aged refuse from a closed landfill.

PubMed

Zhao, Youcai; Song, Liyan; Huang, Renhua; Song, Lijie; Li, Xiong

2007-04-01

In this study, refuse excavated from a typical refuse landfill in Shanghai after 8-10 years of placement was characterized in terms of particle size, total nitrogen, total phosphorus, and biodegradable matter. The refuse contained a large and diverse population of micro-organisms with a high capacity for decomposing refractory organic matter present in some wastewaters, including leachate. It was found that the aged refuse was quite stable after about a decade of decomposition in the warm, humid climate of southern China. The fine fractions resembled and had the properties of black soil, a medium that is suitable for green construction, organic fertilizer, or as bioreactor media for biological treatment of organic wastewaters. Excavation of the aged refuse would make about 50% of the space available for fresh refuse. The plastics, glass, textiles, and cans can be readily mechanically separated and recycled after cleaning. It is estimated that at least 200 millions tonnes of such aged refuse are available in China alone, and at least 10 times that much is buried worldwide. Hence, the evaluation of mined landfill waste and consideration of its potential uses is of great significance.

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.

Environmental biodegradability of [¹⁴C] single-walled carbon nanotubes by Trametes versicolor and natural microbial cultures found in New Bedford Harbor sediment and aerated wastewater treatment plant sludge.

PubMed

Parks, Ashley N; Chandler, G Thomas; Ho, Kay T; Burgess, Robert M; Ferguson, P Lee

2015-02-01

Little is known about environmental biodegradability or biotransformations of single-walled carbon nanotubes (SWNT). Because of their strong association with aquatic organic matter, detailed knowledge of the ultimate fate and persistence of SWNT requires investigation of possible biotransformations (i.e., biodegradation) in environmental media. In the present study, [(14)C]SWNT were utilized to track biodegradation over 6 mo by pure liquid culture of the fungus Trametes versicolor and mixed bacterial isolates from field-collected sediment or aerated wastewater treatment plant sludge. The mixed cultures were chosen as more environmentally relevant media where SWNT will likely be deposited under both aerobic and anaerobic conditions. Activity of [(14)C] was assessed in solid, aqueous, and (14)CO2 gaseous phases to determine amounts of intact SWNT, partially soluble SWNT degradation products, and mineralized SWNT, respectively, during the 6 mo of the experiment. Mass balances based on radiocarbon activity were approximately 100% over 6 mo, and no significant degradation of SWNT was observed. Approximately 99% of the [(14)C] activity remained in the solid phase, 0.8% in the aqueous phase, and less than 0.1% was mineralized to (14)CO2, regardless of culture type. These results suggest that SWNT are not readily biodegraded by pure fungal cultures or environmental microbial communities, and are likely persistent in environmental media. © 2014 SETAC.

Impact of Photooxidation and Biodegradation on the Fate of Oil Spilled During the Deepwater Horizon Incident: Advanced Stages of Weathering.

PubMed

Harriman, Brian H; Zito, Phoebe; Podgorski, David C; Tarr, Matthew A; Suflita, Joseph M

2017-07-05

While the biogeochemical forces influencing the weathering of spilled oil have been investigated for decades, the environmental fate and effects of "oxyhydrocarbons" in sand patties deposited on beaches are not well-known. We collected sand patties deposited in the swash zone on Gulf of Mexico beaches following the Deepwater Horizon oil spill. When sand patties were exposed to simulated sunlight, a larger concentration of dissolved organic carbon was leached into seawater than the corresponding dark controls. This result was consistent with the general ease of movement of seawater through the sand patties as shown with a 35 SO 4 2- radiotracer. Ultrahigh-resolution mass spectrometry, as well as optical measurements revealed that the chemical composition of dissolved organic matter (DOM) leached from the sand patties under dark and irradiated conditions were substantially different, but neither had a significant inhibitory influence on the endogenous rate of aerobic or anaerobic microbial respiratory activity. Rather, the dissolved organic photooxidation products stimulated significantly more microbial O 2 consumption (113 ± 4 μM) than either the dark (78 ± 2 μM) controls or the endogenous (38 μM ± 4) forms of DOM. The changes in the DOM quality and quantity were consistent with biodegradation as an explanation for the differences. These results confirm that sand patties undergo a gradual dissolution of DOM in both the dark and in the light, but photooxidation accelerates the production of water-soluble polar organic compounds that are relatively more amenable to aerobic biodegradation. As such, these processes represent previously unrecognized advanced weathering stages that are important in the ultimate transformation of spilled crude oil.

Manmade organic compounds in the surface waters of the United States: a review of current understanding

USGS Publications Warehouse

Smith, James A.; Witkowski, Patrick J.; Fusillo, Thomas V.

1987-01-01

This report reviews the occurrence and distribution of manmade organic compounds in the surface waters of the United States. On the basis of their aqueous solubilities, nonionic organic compounds partition themselves between water, dissolved organic matter, particulate organic matter, and the lipid reservoirs of aquatic organisms. Ionized organic compounds can be absorbed to sediments, thereby reducing their aqueous concentrations. Transformation processes of photolysis, hydrolysis, biodegradation, and volatilization can attenuate organic compounds, and attenuation rate commonly follow a first-order kinetic process. Eight groups of manmade organic compounds are discussed: 1. Polychlorinated biphenyls and organochlorine insecticides, 2. Carbamate and organophosphorus insecticides, 3. Herbicides, 4. Phenols, 5. Halogenated aliphatic and monocyclic aromatic hydrocarbons, 6. Phthalate esters, 7. Polychlorinated dibenzo-p-dioxins, and 8. Polycyclic aromatic hydrocarbons. For each compound group, data pertaining to use, production, and properties are presented and discussed. Processes that influence that the environmental fate of each group, as determined primarily through laboratory studies, are reviewed, and important fate processes are identified. Environmental concentrations of compounds from each group in water, biota, and sediment are given to demonstrate representative values for comparison to concentrations determined during ongoing research. Finally, where sufficient data exist, regional and temporal contamination trends in the United States are discussed.

Manmade organic compounds in the surface waters of the United States; a review of current understanding

USGS Publications Warehouse

Smith, James A.; Witkowski, P.J.; Fusillo, Thomas V.

1988-01-01

This report reviews the occurrence and distribution of manmade organic compounds in the surface waters of the United States. On the basis of their aqueous solubilities, nonionic organic compounds partition themselves among water, dissolved organic matter, particulate organic matter, and the lipid reservoirs of aquatic organisms. Ionized organic compounds can be adsorbed to sediments, thereby reducing their aqueous concentrations. Transformation processes of photolysis, hydrolysis, biodegradation, and volatilization can attenuate organic compounds, and attenuation rates commonly follow a first-order kinetic process. Eight groups of manmade organic compounds are discussed: 1. Polychlorinated biphenyls and organochlorine insecticides, 2. Carbamate and organophosphorus insecticides, 3. Herbicides, 4. Phenols, 5. Halogenated aliphatic and monocyclic aromatic hydrocarbons, 6. Phthalate esters, 7. Polychlorinated dibenzo-p-dioxins, and 8. Polycyclic aromatic hydrocarbons. For each compound group, data pertaining to use, production, and properties are presented and discussed. Processes that influence the environmental fate of each group, as determined primarily through laboratory studies, are reviewed, and important fate processes are identified. Environmental concentrations of compounds from each group in water, biota, and sediment are given to demonstrate representative values for comparison with concentrations determined during ongoing research. Finally, where data are sufficient, regional and temporal contamination trends in the United States are discussed.

Thermoformed protein based composites in presence of organic acids

USDA-ARS?s Scientific Manuscript database

World industrialization has generated substantial quantities of petroleum-based plastics over many years, which are non biodegradable. There is a growing demand for the use of renewable agricultural sources to develop eco-friendly biobased composites. Agriculture-sourced proteins and starches are b...

Compost biodegradation of recalcitrant hoof keratin by bacteria and fungi.

PubMed

Reuter, T; Gilroyed, B H; Xu, W; McAllister, T A; Stanford, K

2015-08-01

Compost activities efficiently break down a wide range of organic substances over time. In this study, bovine hoof was used as recalcitrant protein model to gain so far cryptic information on biodegradation during livestock mortalities composting. Bovine hooves (black and white), containing different amounts of melanin, placed into nylon bags were monitored during composting of cattle mortalities for up to 230 days. Besides physiochemical analysis, bacterial 16S and fungal 18S DNA fragments were amplified by PCR and profiles were separated by DGGE. Sequence analysis of separated fragments revealed various bacterial and fungal identities during composting. The microbial diversity was affected by a time-temperature interaction and by the hoof colour. Our molecular data, supported by electron microscopy, suggest hoof colonization by shifting bacteria and fungi communities. During composting, microbial communities work collaboratively in the degradation of recalcitrant organic matter such as keratin over time. A number of biomolecules including recalcitrant proteins may persist in environmental reservoirs, but breakdown can occur during composting. A combination of bioactivity and physiochemical conditions appear to be decisive for the fate of persistent biomolecules. © 2015 The Society for Applied Microbiology.

Structure-biodegradability study and computer-automated prediction of aerobic biodegradation of chemicals

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

Klopman, G.; Tu, M.

1997-09-01

It is shown that a combination of two programs, MultiCASE and META, can help assess the biodegradability of industrial organic materials in the ecosystem. MultiCASE is an artificial intelligence computer program that had been trained to identify molecular substructures believed to cause or inhibit biodegradation and META is an expert system trained to predict the aerobic biodegradation products of organic molecules. These two programs can be used to help evaluate the fate of disposed chemicals by estimating their biodegradability and the nature of their biodegradation products under conditions that may model the environment.

Biodegradation of Emiliania huxleyi Aggregates by natural Prokaryotic Communities under Increasing Hydrostatic Pressure.

NASA Astrophysics Data System (ADS)

Riou, V.; Para, J.; Garel, M.; Guigue, C.; Al Ali, B.; Santinelli, C.; Lefèvre, D.; Gattuso, J. P.; Goutx, M.; Panagiotopoulos, C.; Beaufort, L.; Jacquet, S.; Le Moigne, F. A. C.; Tachikawa, K.; Tamburini, C.

2016-02-01

Fluxes of particulate organic carbon (POC) and minerals are positively correlated, suggesting that minerals could enhance the flux of POC into the deep ocean. The so called "ballast effect" posits that minerals could increase sinking particle densities and/or protect the organic matter from heterotrophic degradation. Laboratory controlled experiments on coccolithophorid aggregates under atmospheric pressure show that biogenic calcite both increases particle settling velocities and preserves the organic matter. However, such experiments have yet to include genuine prokaryote rates indicators as well as the effect of increasing pressure. Here, we used the PArticle Sinking Simulator (PASS) to investigate the effect of the increasing pressure on the degradation of Emiliania huxleyi (calcifiers) aggregates. Extra care was taken to obtain culture aggregates with low prokaryotic abundance prior to exposure to natural mesopelagic prokaryotic communities. Particulate organic and inorganic carbon and dissolved organic carbon concentrations were monitored along with the lipid and carbohydrate compositions, as well as prokaryotic community abundance and specific diversity. A control experiment, without natural prokaryotic community addition, indicates that the pressure increase did not have any effect on calcite dissolution observed after ten days. In contrast, the addition of natural prokaryotic community accelerates calcite dissolution under conditions of increasing pressure. Prokaryotic community development and the lipid fraction of E. huxleyi particulate organic carbon are enhanced under increasing pressure. These results suggest that hydrostatic pressure denatures the structural integrity of the carbonate skeleton that protects the cellular organic matter.

Applications of Fluorescence Spectroscopy for dissolved organic matter characterization in wastewater treatment plants

NASA Astrophysics Data System (ADS)

Goffin, Angélique; Guérin, Sabrina; Rocher, Vincent; Varrault, Gilles

2016-04-01

Dissolved organic matter (DOM) influences wastewater treatment plants efficiency (WTTP): variations in its quality and quantity can induce a foaming phenomenon and a fouling event inside biofiltration processes. Moreover, in order to manage denitrification step (control and optimization of the nitrate recirculation), it is important to be able to estimate biodegradable organic matter quantity before biological treatment. But the current methods used to characterize organic matter quality, like biological oxygen demand are laborious, time consuming and sometimes not applicable to directly monitor organic matter in situ. In the context of MOCOPEE research program (www.mocopee.com), this study aims to assess the use of optical techniques, such as UV-Visible absorbance and more specifically fluorescence spectroscopy in order to monitor and to optimize process efficiency in WWTP. Fluorescence excitation-emission matrix (EEM) spectroscopy was employed to prospect the possibility of using this technology online and in real time to characterize dissolved organic matter in different effluents of the WWTP Seine Centre (240,000 m3/day) in Paris, France. 35 sewage water influent samples were collected on 10 days at different hours. Data treatment were performed by two methods: peak picking and parallel factor analysis (PARAFAC). An evolution of DOM quality (position of excitation - emission peaks) and quantity (intensity of fluorescence) was observed between the different treatment steps (influent, primary treatment, biological treatment, effluent). Correlations were found between fluorescence indicators and different water quality key parameters in the sewage influents. We developed different multivariate linear regression models in order to predict a variety of water quality parameters by fluorescence intensity at specific excitation-emission wavelengths. For example dissolved biological oxygen demand (r2=0,900; p<0,0001) and ammonium concentration (r2=0,898; p<0,0001) present good correlation with specific fluorescence peaks and indicators. These indicators derived from 3D spectrofluorescence could be used in order to characterize DOM online and thus to optimize process efficiency in WWTP.

Quantifying biodegradable organic matter in polluted water on the basis of coulombic yield.

PubMed

Liu, Yuan; Tuo, Ai-Xue; Jin, Xiao-Jun; Li, Xiang-Zhong; Liu, Hong

2018-01-01

Biodegradable organic matter (BOM) in polluted water plays a key role in various biological purification technologies. The five-day biochemical oxygen demand (BOD 5 ) index is often used to determine the amount of BOM. However, standard BOD 5 assays, centering on dissolved oxygen detection, have long testing times and often show severe deviation (error ≥ 15%). In the present study, the coulombic yield (Q) of a bio-electrochemical degradation process was determined, and a new index for BOM quantification was proposed. The Q value represents the quantity of transferred electrons from BOM to oxygen, and the corresponding index was defined as BOM Q . By revealing Q-BOM stoichiometric relationship, we were able to perform a BOM Q assay in a microbial fuel cell involved technical platform. Experimental results verified that 5-500mgL -1 of BOM Q toward artificial wastewater samples could be directly obtained without calibration in several to dozens of hours, leaving less than 5% error. Moreover, the BOM Q assay remained accurate and precise in a wide range of optimized operational conditions. A ratio of approximately 1.0 between the values of BOM Q and BOD 5 toward artificial and real wastewater samples was observed. The rapidity, accuracy, and precision of the measurement results are supported by a solid theoretical foundation. Thus, BOM Q is a promising water quality index for quantifying BOM in polluted water. Copyright © 2017 Elsevier B.V. All rights reserved.

Impact of vent pipe diameter on characteristics of waste degradation in semi-aerobic bioreactor landfill.

PubMed

Jiang, Guobin; Liu, Dan; Chen, Weiming; Ye, Zhicheng; Liu, Hong; Li, Qibin

2017-10-01

The evolution mechanism of a vent pipe diameter on a waste-stabilization process in semi-aerobic bioreactor landfills was analyzed from the organic-matter concentration, biodegradability, spectral characteristics of dissolved organic matter, correlations and principal-component analysis. Waste samples were collected at different distances from the vent pipe and from different landfill layers in semi-aerobic bioreactor landfills with different vent pipe diameters. An increase in vent pipe diameter favored waste degradation. Waste degradation in landfills can be promoted slightly when the vent pipe diameter increases from 25 to 50 mm. It could be promoted significantly when the vent pipe diameter was increased to 75 mm. The vent pipe diameter is important in waste degradation in the middle layer of landfills. The dissolved organic matter in the waste is composed mainly of long-wave humus (humin), short-wave humus (fulvic acid) and tryptophan. The humification levels of the waste that was located at the center of vent pipes with 25-, 50- and 75-mm diameters were 2.2682, 4.0520 and 7.6419 Raman units, respectively. The appropriate vent pipe diameter for semi-aerobic bioreactor landfills with an 800-mm diameter was 75 mm. The effect of different vent pipe diameters on the degree of waste stabilization is reflected by two main components. Component 1 is related mainly to the content of fulvic acid, biologically degradable material and organic matter. Component 2 is related mainly to the content of tryptophan and humin from the higher vascular plants.

Effect of influent aeration on removal of organic matter from coffee processing wastewater in constructed wetlands.

PubMed

Rossmann, Maike; Matos, Antonio Teixeira; Abreu, Edgar Carneiro; Silva, Fabyano Fonseca; Borges, Alisson Carraro

2013-10-15

The aim of the present study was to evaluate the influence of aeration and vegetation on the removal of organic matter in coffee processing wastewater (CPW) treated in 4 constructed wetlands (CWs), characterized as follows: (i) ryegrass (Lolium multiflorum) cultivated system operating with an aerated influent; (ii) non-cultivated system operating with an aerated influent, (iii) ryegrass cultivated system operating with a non-aerated influent; and (iv) non-cultivated system operating with a non-aerated influent. The lowest average chemical oxygen demand (COD), biochemical oxygen demand (BOD) and total suspended solids (TSS) removal efficiencies of 87, 84 and 73%, respectively, were obtained in the ryegrass cultivated system operating with a non-aerated influent. However, ryegrass cultivation did not influence the removal efficiency of organic matter. Artificial aeration of the CPW, prior to its injection in the CW, did not improve the removal efficiencies of organic matter. On other hand it did contribute to increase the instantaneous rate at which the maximum COD removal efficiency was reached. Although aeration did not result in greater organic matter removal efficiencies, it is important to consider the benefits of aeration on the removal of the other compounds. Copyright © 2013 Elsevier Ltd. All rights reserved.

Biodegradation of food waste using microbial cultures producing thermostable α-amylase and cellulase under different pH and temperature.

PubMed

Awasthi, Mukesh Kumar; Wong, Jonathan W C; Kumar, Sunil; Awasthi, Sanjeev Kumar; Wang, Quan; Wang, Meijing; Ren, Xiuna; Zhao, Junchao; Chen, Hongyu; Zhang, Zengqiang

2018-01-01

The aim of this work was to study the biodegradation of food waste employing thermostable α-amylase and cellulase enzymes producing bacteria. Four potential isolates were identified which were capable of producing maximum amylase and cellulase and belong to the amylolytic strains, Brevibacillus borstelensis and Bacillus licheniformis; cellulolytic strains, Bacillus thuringiensis and Bacillus licheniformis, respectively. These strains were selected based on its higher cell density, enzymatic activities and stability at a wide range of pH and temperature compared to other strains. The results indicated that 1:1 ratio of pre and post consumed food wastes (FWs) were helpful to facilitate the degradation employing bacterial consortium. In addition, organic matter decomposition and chemical parameters of the end product quality also indicated that bacterial consortium was very effective for 1:1 ratio of FWs degradation as compared to the other treatments. Copyright © 2017 Elsevier Ltd. All rights reserved.

Biodegradation of six haloacetic acids in drinking water.

PubMed

Bayless, Walt; Andrews, Robert C

2008-03-01

Haloacetic acids (HAAs) are produced by the reaction of chlorine with natural organic matter and are regulated disinfection by-products of health concern. Biofilms in drinking water distribution systems and in filter beds have been associated with the removal of some HAAs, however the removal of all six routinely monitored species (HAA(6)) has not been previously reported. In this study, bench-scale glass bead columns were used to investigate the ability of a drinking water biofilm to degrade HAA(6). Monochloroacetic acid (MCAA) and monobromoacetic acid (MBAA) were the most readily degraded of the halogenated acetic acids. Trichloroacetic acid (TCAA) was not removed biologically when examined at a 90% confidence level. In general, di-halogenated species were removed to a lesser extent than the mono-halogenated compounds. The order of biodegradability by the biofilm was found to be monobromo > monochloro > bromochloro > dichloro > dibromo > trichloroacetic acid.

Research regarding biodegradable properties of food polymeric products under microorganism activity

NASA Astrophysics Data System (ADS)

Opran, Constantin; Lazar, Veronica; Fierascu, Radu Claudiu; Ditu, Lia Mara

2018-02-01

Aim of this research is the structural analysis by comparison of the biodegradable properties of two polymeric products made by non-biodegradable polymeric material (polypropylene TIPPLEN H949 A) and biodegradable polymeric material (ECOVIO IS 1335), under microorganism activity in order to give the best solution for the manufacture of food packaging biodegradable products. It presents the results of experimental determinations on comparative analysis of tensile strength for the two types of polymers. The sample weight variations after fungal biodegradation activity revealed that, after 3 months, there are no significant changes in polymeric substratum for non-biodegradable polymeric. The microscopically analysis showed that the fungal filaments did not strongly adhered on the non-biodegradable polymeric material, instead, both filamentous fungi strains adhered and covered the surface of the biodegradable sample with germinated filamentous conidia. The spectral analysis of polymer composition revealed that non-biodegradable polymer polypropylene spectra are identical for control and for samples that were exposed to fungal activity, suggesting that this type of sample was not degraded by the fungi strains. Instead, for biodegradable polymer sample, it was observed significant structural changes across multiple absorption bands, suggesting enzyme activity manifested mainly by Aspergillus niger strain. Structural analysis of interdisciplinary research results, lead, to achieving optimal injection molded technology emphasizing technological parameters, in order to obtain food packaging biodegradable products.

REMOVAL OF MTBE FROM WATER WITH ZEOLITES

EPA Science Inventory

MTBE has impacted public drinking water wells from releases of gasoline making the water non-potable. MTBE is highly soluble in water, has a low volatility, does not adsorb strongly to soil, and is not thought to be easily biodegradable. Traditional methods of removing organics ...

Fate of natural organic matter at a full-scale Drinking Water Treatment Plant in Greece.

PubMed

Papageorgiou, A; Papadakis, N; Voutsa, D

2016-01-01

The aim of this study was to investigate the fate of natural organic matter (NOM) and subsequent changes during the various treatment processes at a full-scale Drinking Water Treatment Plant (DWTP). Monthly sampling campaigns were conducted for 1 year at six sites along DWTP of Thessaloniki, Northern Greece including raw water from the Aliakmonas River that supplies DWTP and samples from various treatment processes (pre-ozonation, coagulation, sand filtration, ozonation, and granular activated carbon (GAC) filtration). The concentration of NOM and its characteristics as well as the removal efficiency of various treatment processes on the basis of dissolved organic carbon, UV absorbance, specific ultra-violet absorbance, fluorescence intensity, hydrophobicity, biodegradable dissolved organic carbon, and formation potential of chlorination by-products trihalomethanes (THMs) and haloacetic acids (HAAs) were studied. The concentration of dissolved organic carbon (DOC) in reservoir of the Aliakmonas River ranged from 1.46 to 1.84 mg/L, exhibiting variations regarding UV, fluorescence, and hydrophobic character through the year. Along DWTP, a significant reduction of aromatic, fluorophoric, and hydrophobic character of NOM was observed resulting in significant elimination of THM (63%) and HAAs (75%) precursors.

BTEX biodegradation by bacteria from effluents of petroleum refinery.

PubMed

Mazzeo, Dânia Elisa Christofoletti; Levy, Carlos Emílio; de Angelis, Dejanira de Franceschi; Marin-Morales, Maria Aparecida

2010-09-15

Groundwater contamination with benzene, toluene, ethylbenzene and xylene (BTEX) has been increasing, thus requiring an urgent development of methodologies that are able to remove or minimize the damages these compounds can cause to the environment. The biodegradation process using microorganisms has been regarded as an efficient technology to treat places contaminated with hydrocarbons, since they are able to biotransform and/or biodegrade target pollutants. To prove the efficiency of this process, besides chemical analysis, the use of biological assessments has been indicated. This work identified and selected BTEX-biodegrading microorganisms present in effluents from petroleum refinery, and evaluated the efficiency of microorganism biodegradation process for reducing genotoxic and mutagenic BTEX damage through two test-systems: Allium cepa and hepatoma tissue culture (HTC) cells. Five different non-biodegraded BTEX concentrations were evaluated in relation to biodegraded concentrations. The biodegradation process was performed in a BOD Trak Apparatus (HACH) for 20 days, using microorganisms pre-selected through enrichment. Although the biodegradation usually occurs by a consortium of different microorganisms, the consortium in this study was composed exclusively of five bacteria species and the bacteria Pseudomonas putida was held responsible for the BTEX biodegradation. The chemical analyses showed that BTEX was reduced in the biodegraded concentrations. The results obtained with genotoxicity assays, carried out with both A. cepa and HTC cells, showed that the biodegradation process was able to decrease the genotoxic damages of BTEX. By mutagenic tests, we observed a decrease in damage only to the A. cepa organism. Although no decrease in mutagenicity was observed for HTC cells, no increase of this effect after the biodegradation process was observed either. The application of pre-selected bacteria in biodegradation processes can represent a reliable and effective tool in the treatment of water contaminated with BTEX mixture. Therefore, the raw petroleum refinery effluent might be a source of hydrocarbon-biodegrading microorganisms. Copyright 2010 Elsevier B.V. All rights reserved.

Effect of ultrasonication on anaerobic degradability of solid waste digestate.

PubMed

Boni, M R; D'Amato, E; Polettini, A; Pomi, R; Rossi, A

2016-02-01

This paper evaluates the effect of ultrasonication on anaerobic biodegradability of lignocellulosic residues. While ultrasonication has been commonly applied as a pre-treatment of the feed substrate, in the present study a non-conventional process configuration based on recirculation of sonicated digestate to the biological reactor was evaluated at the lab-scale. Sonication tests were carried out at different applied energies ranging between 500 and 50,000kJ/kg TS. Batch anaerobic digestion tests were performed on samples prepared by mixing sonicated and untreated substrate at two different ratios (25:75 and 75:25 w/w). The results showed that when applied as a post-treatment of digestate, ultrasonication can positively affect the yield of anaerobic digestion, mainly due to the dissolution effect of complex organic molecules that have not been hydrolyzed by biological degradation. A good correlation was found between the CH4 production yield and the amount of soluble organic matter at the start of digestion tests. The maximum gain in biogas production was 30% compared to that attained with the unsonicated substrate, which was tentatively related to the type and concentration of the metabolic products. Copyright © 2015 Elsevier Ltd. All rights reserved.

How the origin of fresh household waste affects its ability to be biodegraded: an assessment using basic tools and its application to the city of Kara in Togo.

PubMed

Segbeaya, K N; Feuillade-Cathalifaud, G; Baba, G; Koledzi, E K; Pallier, V; Tchangbedji, G; Matejka, G

2012-12-01

Waste biodegradation has been largely investigated in the literature by using conventional tests like the BMP test and the respirometric test, whereas only few studies deal with the use of leaching tests in combination with biological activity measurements. Consequently, this study used an improved leaching test to evaluate the biodegradability of two deposits of fresh household waste from the city of Kara in Togo. The first deposit came from households in neighborhoods located in the outskirts of the city and the second consisted of fresh waste, mainly composed of business waste and household waste, collected in the urban center and aimed at being deposited in the landfill. A physicochemical characterization of the two deposits completed the leaching test. The biological activity was monitored by measuring O(2) consumption and CO(2) production. pH, DOC/OM, VFA/DOC ratios and the SUVA index was measured in the leaching juice to assess both the state of degradation of the waste in the deposits and the ability of the organic matter to be mobilized quickly and to be easily assimilated by microorganisms. The biodegradability of waste from the city of Kara correlated with their origin even though the physical characteristics of the two deposits studied differed greatly. Copyright © 2012 Elsevier Ltd. All rights reserved.

Matrix effect on the performance of headspace solid phase microextraction method for the analysis of target volatile organic compounds (VOCs) in environmental samples.

PubMed

Higashikawa, Fábio S; Cayuela, Maria Luz; Roig, Asunción; Silva, Carlos A; Sánchez-Monedero, Miguel A

2013-11-01

Solid phase microextraction (SPME) is a fast, cheap and solvent free methodology widely used for environmental analysis. A SPME methodology has been optimized for the analysis of VOCs in a range of matrices covering different soils of varying textures, organic matrices from manures and composts from different origins, and biochars. The performance of the technique was compared for the different matrices spiked with a multicomponent VOC mixture, selected to cover different VOC groups of environmental relevance (ketone, terpene, alcohol, aliphatic hydrocarbons and alkylbenzenes). VOC recovery was dependent on the nature itself of the VOC and the matrix characteristics. The SPME analysis of non-polar compounds, such as alkylbenzenes, terpenes and aliphatic hydrocarbons, was markedly affected by the type of matrix as a consequence of the competition for the adsorption sites in the SPME fiber. These non-polar compounds were strongly retained in the biochar surfaces limiting the use of SPME for this type of matrices. However, this adsorption capacity was not evident when biochar had undergone a weathering/aging process through composting. Polar compounds (alcohol and ketone) showed a similar behavior in all matrices, as a consequence of the hydrophilic characteristics, affected by water content in the matrix. SPME showed a good performance for soils and organic matrices especially for non-polar compounds, achieving a limit of detection (LD) and limit of quantification (LQ) of 0.02 and 0.03 ng g(-1) for non-polar compounds and poor extraction for more hydrophilic and polar compounds (LD and LQ higher 310 and 490 ng g(-1)). The characteristics of the matrix, especially pH and organic matter, had a marked impact on SPME, due to the competition of the analytes for active sites in the fiber, but VOC biodegradation should not be discarded in matrices with active microbial biomass. Copyright © 2013 Elsevier Ltd. All rights reserved.

ELECTROSPUN MESOFIBERS, A NOVEL BIODEGRADABLE PHEROMONE DISPENSER TECHNOLOGY, ARE COMBINED WITH MECHANICAL DEPLOYMENT FOR EFFICIENT IPM OF LOBESIA BOTRANA IN VINEYARDS.

PubMed

Hummel, Hans E; Langner, S S; Breuer, M

2015-01-01

Behaviour modifying pheromones are well known agents for disrupting mating communication of pest insects. For optimal activity, they must be dispensed in time and space at a quantitatively measurable, predetermined release rate covering the flight period of the target species. Pheromones appeal to environmentally conscientious entomologists for their biodegradability, non-toxicity and ecological compatibility. In attempts of combining the virtues of pheromones, suitable slow release dispensers, and their mechanical deployment, an ecologically sensible, reasonably priced and patented procedure was developed and tested with the vineyard pest Lobesia botrana (Lep.: Tortricidae). It is characterized by (1) Electrospun mesofibers with diameters ranging from 0.6 to 3.5 micrometres, containing disruptants and dispensing it by slow release diffusion into the crop, (2) simultaneous application of the fully biodegradable combination of pheromone with Ecoflex polyester mesofiber, (3) combination of mechanical deployment by multi-purpose cultivators of the prefabricated pheromone dispensers with other simultaneous cultivation measures, and thus further reducing labour time and treatment costs. The dispensers are biodegradable within half a year without leaving any objectionable residues. In the standard eco-toxicology tests pheromone dispensers are harmless to non-target organisms. The disruptive effect of one treatment lasts for seven weeks which covers well one of several flight periods of L. botrana.

Effects of exogenous aerobic bacteria on methane production and biodegradation of municipal solid waste in bioreactors.

PubMed

Ge, Sai; Liu, Lei; Xue, Qiang; Yuan, Zhiming

2016-09-01

Landfill is the most common and efficient ways of municipal solid waste (MSW) disposal and the landfill biogas, mostly methane, is currently utilized to generate electricity and heat. The aim of this work is to study the effects and the role of exogenous aerobic bacteria mixture (EABM) on methane production and biodegradation of MSW in bioreactors. The results showed that the addition of EABM could effectively enhance hydrolysis and acidogenesis processes of MSW degradation, resulting in 63.95% reduction of volatile solid (VS), the highest methane production rate (89.83Lkg(-1) organic matter) ever recorded and a threefold increase in accumulative methane production (362.9L) than the control (127.1L). In addition, it is demonstrated that white-rot fungi (WRF) might further promote the methane production through highly decomposing lignin, but the lower pH value in leachate and longer acidogenesis duration may cause methane production reduced. The data demonstrated that methane production and biodegradation of MSW in bioreactors could be significantly enhanced by EABM via enhanced hydrolysis and acidogenesis processes, and the results are of great economic importance for the future design and management of landfill. Copyright © 2015 Elsevier Ltd. All rights reserved.

Characterization of dissolved organic matter in landfill leachate during the combined treatment process of air stripping, Fenton, SBR and coagulation

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

Liu, ZhiPing, E-mail: liulqs@163.com; Faculty of Urban Construction and Environmental Engineering, Chongqing University, Chongqing 400020; Wu, WenHui

Highlights: • DOM fractions spectra analysis during the whole treatment process. • Efficient method was achieved to remove organic matters in landfill leachate. • Molecular weight distribution and fractions were discussed. - Abstract: A combined treatment process of air stripping + Fenton + sequencing batch reactor (SBR)+ coagulation was performed to remove the pollutants in landfill leachate. Molecular weight (MW) distribution and fractions of dissolved organic matter (DOM) were discussed to study the characteristics. The experiment showed that the removal rate of chemical oxygen demand (COD), five day biological oxygen demand (BOD{sub 5}) and ammonia nitrogen (NH{sub 3}−N) by themore » combined process were 92.8%, 87.8% and 98.0%, respectively. Humic acid (HA) and fulvic acid (FA) were the main fractions in raw leachate with 81.8% of the total COD concentration, while hydrophilic organic matter (HyI) was the dominant fraction in the final effluent of the combined process with 63.5% of the total COD concentration. After the combined treatment process, the removal rate of DOM and fractions HA, FA, HyI were 91.9%, 97.1%, 95.8% and 71.7%, respectively. Organic matters of MW < 2 k and MW > 100 k were removed with 90.5% and 97.9% COD concentration after the treatment. The ultraviolet–visible spectra (UV–vis), Fourier transform infrared spectra (FTIR) and three-dimensional excitation-emission matrices spectra (EEMs) indicated that benzene materials and phenol compounds were preferentially removed in air stripping. High MW matters, aromatic rings, conjugated moieties and some functional groups were mainly removed by Fenton. While small MW fractions, carboxylic acids, alcohols and protein-like materials were preferentially biodegraded via SBR. Fulvic-like and humic-like materials were mainly destroyed via Fenton oxidation and coagulation.« less

[The remove characteristics of dissolved organic matter in landfill leachate during the treatment process].

PubMed

He, Xiao-Song; Yu, Jing; Xi, Bei-Dou; Jiang, Yong-Hai; Zhang, Jin-Bao; Li, Dan; Pan, Hong-Wei; Liu, Hong-Liang

2012-09-01

In order to investigate remove characteristics of dissolved organic matter in landfill leachate, leachates were sampled during the process (i. e. , adjusting tank, anaerobic zone, oxidation ditch and MBR processing). Dissolved organic matter was extracted and its content and structure were characterized by fluorescence excitation-emission matrix spectra, UV-Vis specrtra and FTIR spectra. The results showed that an amount of 377.6 mg x L(-1) dissolved organic carbon (DOC) was removed during the whole treatment process, and the total removal rate was up to 78.34%. The 25.56% of DOC in the adjusting tank was removed during the anaerobic zone, 41.58% of DOC in anaerobic effluent was removed during the oxidation ditch, while 50.19% of DOC in the oxidation ditch effluent decreased in the MBR process. The anaerobic process increased the content of unsaturated compound and polysaccharides in leachate DOM, which improved the leachate biochemical characteristics. The unsaturated compound and polysaccharides were removed effectively during being in oxidation ditch. Protein-like and humic-like fluorescence peaks were observed in the adjusting tank and anaerobic zone, while humic-like fluorescence peaks were just presented in the oxidation ditch and MBR processing. Protein-like and fulvic-like substances were biodegraded in the adjusting tank and anaerobic zone, while humic-like materials were removed in the MBR process.

Removal and transformation of effluent organic matter (EfOM) in biotreated textile wastewater by GAC/O3 pre-oxidation and enhanced coagulation.

PubMed

Qian, Feiyue; Sun, Xianbo; Liu, Yongdi; Xu, Hongyong

2013-01-01

GAC/O3 (ozonation in the presence of granular activated carbon) combined with enhanced coagulation was employed to process biotreated textile wastewater for possible reuse. The doses of ozone, GAC and coagulant were the variables studied for optimization. The effects of different treatment processes on effluent organic matter (EfOM) characteristics, including biodegradability, hydrophobic and hydrophilic nature, and apparent molecular weight (AMW) distribution were also investigated. Compared with ozonation, GAC/O3 not only presented a higher pre-oxidation efficiency, but also improved the treatability of hydrophobic and high molecular weight compounds by enhanced coagulation. After treatment by GAC/O3 pre-oxidation (0.6 mg O3 x mg(-1) COD and 20 g x L(-1) GAC) and enhanced coagulation (25 mg x L(-1) Al3+ at pH 5.5), the removal efficiencies of chemical oxygen demand (COD), dissolved organic carbon (DOC) and colour were higher than those for coagulation alone by 17.3%, 12.0% and 25.6%, respectively. Residual organic matter consisted mainly of hydrophobic acids and hydrophilic compounds of AMW < 1 kDa, which were colourless and of limited biological availability. The combination of GAC/O3 and enhanced coagulation was proved to be a simple and effective treatment strategy for removing EfOM from biotreated textile wastewater.

Composition and Biolability of Dissolved Organic Matter Leached from the Dominant Endmembers of the Siberian Arctic

NASA Astrophysics Data System (ADS)

Borgen, M.; Spencer, R. G.; Mann, P. J.; Vonk, J. E.; Bulygina, E. B.; Holmes, R. M.

2012-12-01

Terrigenous dissolved organic matter (DOM) has historically been thought to be refractory as it is mobilized into and transported through Arctic fluvial networks. However, a growing body of evidence suggests that this DOM, largely leached from vegetation, soils, and litter during the annual freshet, is highly biolabile. This study examined DOM leached from these dominant endmembers of the Kolyma River watershed in the Siberian Arctic. As leachates progressed through time, measurements of dissolved organic carbon (DOC), optical parameters to assess DOM composition, and biodegradation incubations were undertaken. This suite of measurements allowed examination of the rate and composition of leached DOC into the aquatic system and quantification of the biolability of the DOM from the diverse range of endmembers examined. Of all the endmembers, vascular plants leached the greatest amount of DOC and results will be presented relating DOC concentration and DOM composition to initial source material. Furthermore, controls on DOM biolability, enzymatic activity, and the ultimate fate of terriginous DOC in Siberian fluvial systems will be discussed.

Raw liquid waste treatment process

NASA Technical Reports Server (NTRS)

Humphrey, Marshall F. (Inventor)

1980-01-01

A raw sewage treatment process is disclosed in which substantially all the non-dissolved matter, which is suspended in the sewage water is first separated from the water, in which at least organic matter is dissolved. The non-dissolved material is pyrolyzed to form an activated carbon and ash material without the addition of any conditioning agents. The activated carbon and ash material is added to the water from which the non-dissolved matter was removed. The activated carbon and ash material absorbs organic matter and heavy metal ions, it is believed, are dissolved in the water and is thereafter supplied in a counter current flow direction and combined with the incoming raw sewage to facilitate the separation of the non-dissolved settleable materials from the sewage water. The used carbon and ash material together with the non-dissolved matter which was separated from the sewage water are pyrolyzed to form the activated carbon and ash material.

Raw Liquid Waste Treatment System and Process

NASA Technical Reports Server (NTRS)

Humphrey, M. F. (Inventor)

1974-01-01

A raw sewage treatment process is disclosed in which substantially all the non-dissolved matter, suspended in the sewage water is first separated from the water, in which at least organic matter remains dissolved. The non-dissolved material is pyrolyzed to form an activated carbon and ash material without the addition of any conditioning agents. The activated carbon and ash material is added to the water from which the non-dissolved matter was removed. The activated carbon and ash material adsorbs the organic matter dissolved in the water and is thereafter supplied in a counter flow direction and combined with the incoming raw sewage to at least facilitate the separation of the non-dissolved settleable materials from the sewage water. Carbon and ash material together with the non-dissolved matter which was separated from the sewage water are pyrolyzed to form the activated carbon and ash material.

Fractionation and removal of dissolved organic carbon in a full-scale granular activated carbon filter used for drinking water production.

PubMed

Gibert, Oriol; Lefèvre, Benoît; Fernández, Marc; Bernat, Xavier; Paraira, Miquel; Pons, Marc

2013-05-15

The removal of natural organic matter (NOM) and, more particularly, its individual fractions by two different GACs was investigated in full-scale filters in a drinking water treatment plant (DWTP). Fractionation of NOM was performed by high performance size exclusion chromatography (HPSEC) into biopolymers, humic substances, building blocks and low molecular weight organics. The sorption capacity of GAC in terms of iodine number (IN) and apparent surface area (SBET), as well as the filling of narrow- and super-microporosity were monitored over the 1-year operation of the filters. Both GACs demonstrated to be effective at removing NOM over a wide range of fractions, especially the low and intermediate molecular weight fractions. TOC removal initially occurred via adsorption, and smaller (lighter) fractions were more removed as they could enter and diffuse more easily through the pores of the adsorbent. As time progressed, biodegradation also played a role in the TOC removal, and lighter fractions continued to be preferentially removed due to their higher biodegradability. The gained knowledge would assist drinking water utilities in selecting a proper GAC for the removal of NOM from water and, therefore, complying more successfully the latest water regulations. Copyright © 2013 Elsevier Ltd. All rights reserved.

[Agroindustrial wastes methanization and bacterial composition in anaerobic digestion].

PubMed

González-Sánchez, María E; Pérez-Fabiel, Sergio; Wong-Villarreal, Arnoldo; Bello-Mendoza, Ricardo; Yañez-Ocampo, Gustavo

2015-01-01

The tons of organic waste that are annually generated by agro-industry, can be used as raw material for methane production. For this reason, it is important to previously perform biodegradability tests to organic wastes for their full scale methanization. This paper addresses biodegradability, methane production and the behavior of populations of eubacteria and archaeabacteria during anaerobic digestion of banana, mango and papaya agroindustrial wastes. Mango and banana wastes had higher organic matter content than papaya in terms of their volatile solids and total solid rate (94 and 75% respectively). After 63 days of treatment, the highest methane production was observed in banana waste anaerobic digestion: 63.89ml CH4/per gram of chemical oxygen demand of the waste. In the PCR-DGGE molecular analysis, different genomic footprints with oligonucleotides for eubacteria and archeobacteria were found. Biochemical methane potential results proved that banana wastes have the best potential to be used as raw material for methane production. The result of a PCR- DGGE analysis using specific oligonucleotides enabled to identify the behavior of populations of eubacteria and archaeabacteria present during the anaerobic digestion of agroindustrial wastes throughout the process. Copyright © 2015 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Characterization and biodegradation of water-soluble biomarkers and organic carbon extracted from low temperature chars

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

Norwood, Matt J.; Louchouarn, Patrick; Kuo, Li-Jung

This study demonstrates that wildfires/biomass combustion may be an important source of labile pyrogenic water-soluble organic matter (Py-WSOM) to aquatic systems. Spectroscopic analysis (of the solid char and Py-WSOM) with Fourier transform infrared spectroscopy (FTIR) indicated that the Py-WSOM extracted from two low temperature chars (one wood, one grass) was dominated by polar moieties (-OH and C-O) derived from depolymerization and fragmentation of lignocellulose. Incubation experiments under aerobic conditions with unsterilized river water suggested that Py-WSOM and associated biomarkers may have turnover rates on the order of weeks to months, consistent with mixing and transport conditions of riverine systems. Formore » example, pyrogenic dissolved organic carbon (Py-DOC) had a half-life of 30-40 days. Turnover rate for the combustion biomarkers was shorter, with levoglucosan and free lignin phenols having a half-life around 3-4 days and polymeric lignin components 13-14 days. The latter observations contradict earlier studies on the biodegradation of dissolved lignin and point to the need for re-assessment of lignin degradation kinetics in well-mixed riverine systems, particularly when such lignin components are derived from thermally altered plant material that may exist in a form more labile than that in highly processed riverine DOM.« less

Advanced characterisation of organic matter in oil sands and tailings sands used for land reclamation by Fourier transform-ion cyclotron resonance-mass spectrometry (FT-ICR-MS)

NASA Astrophysics Data System (ADS)

Noah, M.; Vieth-Hillebrand, A.; Wilkes, H.

2012-04-01

The Athabasca region of northern Alberta, Canada, is home to deposits of oil sands containing vast amounts (~ 173 billion barrels) of heavily biodegraded petroleum. Oil sands are recovered by surface mining or by in situ steam injection. The extraction of bitumen from oil sands by caustic hot water processing results in large volumes of fluid tailings, which are stored in on-site settling basins. There the tailings undergo a compaction and dewatering process, producing a slowly densifying suspension. The released water is recycled for extraction. The fine tailings will be reclaimed as either dry or wet landscapes. [1] To produce 1 barrel of crude oil, 2 tons of oil sand and 2 - 3 tons of water (including recycled water) are required. [2] Open pit mining and the extraction of the bitumen from the oil sands create large and intense disturbances of different landscapes. The area currently disturbed by mining operations covers about 530 km2 and the area of tailing ponds surpasses 130 km2. An issue of increasing importance is the land remediation and reclamation of oil sand areas in Canada and the reconstruction of these disturbed landscapes back to working ecosystems similar to those existing prior to mining operations. An important issue in this context is the identification of oil sand-derived organic compounds in the tailings, their environmental behaviour and the resulting chances and limitations with respect to land reclamation. Furthermore the biodegradation processes that occur in the tailings and that could lead to a decrease in hazardous organic compounds are important challenges, which need to be investigated. This presentation will give a detailed overview of our compositional and quantitative characterisation of the organic matter in oil sand, unprocessed and processed mature fine tailings samples as well as in tailings sands used as part of land reclamation. The analytical characterisation is based on the extraction of the soluble organic matter, its subsequent separation into asphaltenes, aliphatic hydrocarbons, aromatic hydrocarbons, neutral nitrogen, sulphur, oxygen (NSO) compounds and carboxylic acids. The asphaltene fractions are analysed using pyrolysis-GC, all other fractions are analysed by GC-MS. Additionally Fourier transform-ion cyclotron resonance-mass spectrometry (FT-ICR-MS) is used to study the chemical composition of the samples on the molecular level using different ionisation methods.

Study of methanogenesis during bioutilization of plant residuals

NASA Astrophysics Data System (ADS)

Ilyin, V. K.; Korniushenkova, I. N.; Starkova, L. V.; Lauriniavichius, K. S.

2005-02-01

The waste management strategy for the future should meet the benefits of human safety, respect principles of planet ecology, and compatibility with other habitability systems. For these purposes waste management technologies relevant to application of the biodegradation properties of bacteria are of great value. Biological treatment method is based on the biodegradation of organic substances by various microorganisms. The objectives of our study were: to evaluate the effectiveness of microbial biodegradation of vegetable non-edible residual, using artificial inoculum, and to study the peculiarities of biogas, and possibilities of optimizing or reducing the share of methane. The diminution rate of organic gained 76% from initial mass within 9 days of fermentation. The biogas production achieved 46 l/kg of substrate. The microbial studies of biodegradation process revealed the following peculiarities: (i) gradual quantitative increase of Lactobacillus sp. (from 103 to 105 colony-forming units (CFU) per ml); (ii) activation of Clostridia sp. (from 102 to 10 4 CFU/ml); and (iii) elimination of aerobic conventional pathogens (Enterobacteriaceae, Protea sp., Staphylococci). Chromatography analysis revealed the constant presence of carbon dioxide (up to 90.9%). The methane content measures revealed traces 0.1-0.4%. However, when we optimized the methane production in "boiling layer" using methanogenic granules, the amount of methane in biogas reached 80-90%. Based on the results obtained the artificial inoculum was created which was capable of initiating biodegradation of vegetable wastes. This inoculum consisted of active sludge adapted to wastes mixed with excretea of insects which consume plant wastes. Using this inoculum the biodegradation process takes less time than that using active sludge. Regulation of methane concentration from traces to 90% may be achieved by adding methane reactor to the plant digester.

Green Synthesis of Fe and Fe/Pd Bimetallic Nanoparticles in Membranes for Reductive Degradation of Chlorinated Organics

EPA Science Inventory

Membranes containing reactive nanoparticles (Fe and Fe/Pd) immobilized in a polymer film (polyacrylic acid, PAA-coated polyvinylidene fluoride, PVDF membrane) are prepared by a new method. In the present work a biodegradable, non-toxic -“green” reducing agent, green tea extract ...

Toxicity threshold of chitosan for the subterranean termite, Reticulitermes flavipes

Treesearch

Olanrewaju Raji; Telmah Telmadarrehei; Juliet D. Tang; Dragica Jeremic

2015-01-01

Chitosan is a hydrophilic and biodegradable polysaccharide with antimicrobial properties. It has low toxicity to non-target organisms and is considered an environmentally friendly preservative. In this study, the efficacy of chitosan polymer (> 50 kDa) as a wood preservative was evaluated against the subterranean termites Reticulitermes flavipes...

Anaerobic storage as a pretreatment for enhanced biodegradability of dewatered sewage sludge.

PubMed

Xu, Huacheng; He, Pinjing; Wang, Guanzhao; Shao, Liming; Lee, Duujong

2011-01-01

Dewatered sewage sludge is often stored still before further processing and final disposal. This study showed that anaerobic storage of dewatered sewage sludge could hydrolyze organic matter from the sludge matrix, and increase soluble organic acid content from 90 to 2400 mg/L and soluble organic carbon content from 220 to 1650 mg/L. Correspondingly, the contents of proteins, celluloses and hemicelluloses were reduced by 2-9%. Applying anaerobic storage markedly enhanced the efficiency of the subsequent bio-drying process on stored sludge. Correspondingly, biogas and odor gas were produced immediately after commencing the sludge storage. Anaerobic storage with odor control can be applied as a pretreatment process for dewatered sewage sludge in wastewater treatment plants. Copyright © 2010 Elsevier Ltd. All rights reserved.

Chitin: 'Forgotten' Source of Nitrogen: From Modern Chitin to Thermally Mature Kerogen: Lessons from Nitrogen Isotope Ratios

USGS Publications Warehouse

Schimmelmann, A.; Wintsch, R.P.; Lewan, M.D.; DeNiro, M.J.

1998-01-01

Chitinous biomass represents a major pool of organic nitrogen in living biota and is likely to have contributed some of the fossil organic nitrogen in kerogen. We review the nitrogen isotope biogeochemistry of chitin and present preliminary results suggesting interaction between kerogen and ammonium during thermal maturation. Modern arthropod chitin may shift its nitrogen isotope ratio by a few per mil depending on the chemical method of chitin preparation, mostly because N-containing non-amino-sugar components in chemically complex chitin cannot be removed quantitatively. Acid hydrolysis of chemically complex chitin and subsequent ion-chromatographic purification of the "deacetylated chitin-monomer" D-glucosamine (in hydrochloride form) provides a chemically well-defined, pure amino-sugar substrate for reproducible, high-precision determination of ??15N values in chitin. ??15N values of chitin exhibited a variability of about one per mil within an individual's exoskeleton. The nitrogen isotope ratio differed between old and new exoskeletons by up to 4 per mil. A strong dietary influence on the ??15N value of chitin is indicated by the observation of increasing ??15N values of chitin from marine crustaceans with increasing trophic level. Partial biodegradation of exoskeletons does not significantly influence ??15N values of remaining, chemically preserved amino sugar in chitin. Diagenesis and increasing thermal maturity of sedimentary organic matter, including chitin-derived nitrogen-rich moieties, result in humic compounds much different from chitin and may significantly change bulk ??15N values. Hydrous pyrolysis of immature source rocks at 330??C in contact with 15N-enriched NH4Cl, under conditions of artificial oil generation, demonstrates the abiogenic incorporation of inorganic nitrogen into carbon-bound nitrogen in kerogen. Not all organic nitrogen in natural, thermally mature kerogen is therefore necessarily derived from original organic matter, but may partly result from reaction with ammonium-containing pore waters.

Application of stable isotope ratio analysis for biodegradation monitoring in groundwater

USGS Publications Warehouse

Hatzinger, Paul B.; Böhlke, John Karl; Sturchio, Neil C.

2013-01-01

Stable isotope ratio analysis is increasingly being applied as a tool to detect, understand, and quantify biodegradation of organic and inorganic contaminants in groundwater. An important feature of this approach is that it allows degradative losses of contaminants to be distinguished from those caused by non-destructive processes such as dilution, dispersion, and sorption. Recent advances in analytical techniques, and new approaches for interpreting stable isotope data, have expanded the utility of this method while also exposing complications and ambiguities that must be considered in data interpretations. Isotopic analyses of multiple elements in a compound, and multiple compounds in the environment, are being used to distinguish biodegradative pathways by their characteristic isotope effects. Numerical models of contaminant transport, degradation pathways, and isotopic composition are improving quantitative estimates of in situ contaminant degradation rates under realistic environmental conditions.

Evaluation of natural materials as exogenous carbon sources for biological treatment of low carbon-to-nitrogen wastewater.

PubMed

Ramírez-Godínez, Juan; Beltrán-Hernández, Icela; Álvarez-Hernández, Alejandro; Coronel-Olivares, Claudia; Contreras-López, Elizabeth; Quezada-Cruz, Maribel; Vázquez-Rodríguez, Gabriela

2015-01-01

In the bacterial processes involved in the mitigation of nitrogen pollution, an adequately high carbon-to-nitrogen (C : N) ratio is key to sustain denitrification. We evaluated three natural materials (woodchips, barley grains, and peanut shells) as carbon sources for low C : N wastewater. The amount of organic matter released from these materials to aqueous media was evaluated, as well as their pollution swapping potential by measuring the release of total Kjeldahl nitrogen, N-NH4 (+), NO2 (-), and NO3 (-), and total phosphorous. Barley grains yielded the highest amount of organic matter, which also showed to be the most easily biodegradable. Woodchips and peanut shells released carbon rather steadily and so they would not require frequent replenishment from biological reactors. These materials produced eluates with lower concentrations of nutrients than the leachates from barley grains. However, as woodchips yielded lower amounts of suspended solids, they constitute an adequate exogenous source for the biological treatment of carbon-deficient effluents.

Evaluation of Natural Materials as Exogenous Carbon Sources for Biological Treatment of Low Carbon-to-Nitrogen Wastewater

PubMed Central

Ramírez-Godínez, Juan; Beltrán-Hernández, Icela; Álvarez-Hernández, Alejandro; Coronel-Olivares, Claudia; Contreras-López, Elizabeth; Quezada-Cruz, Maribel

2015-01-01

In the bacterial processes involved in the mitigation of nitrogen pollution, an adequately high carbon-to-nitrogen (C : N) ratio is key to sustain denitrification. We evaluated three natural materials (woodchips, barley grains, and peanut shells) as carbon sources for low C : N wastewater. The amount of organic matter released from these materials to aqueous media was evaluated, as well as their pollution swapping potential by measuring the release of total Kjeldahl nitrogen, N-NH4 +, NO2 −, and NO3 −, and total phosphorous. Barley grains yielded the highest amount of organic matter, which also showed to be the most easily biodegradable. Woodchips and peanut shells released carbon rather steadily and so they would not require frequent replenishment from biological reactors. These materials produced eluates with lower concentrations of nutrients than the leachates from barley grains. However, as woodchips yielded lower amounts of suspended solids, they constitute an adequate exogenous source for the biological treatment of carbon-deficient effluents. PMID:26495313

SUSTAINABLE PACKAGING SOLUTIONS BASED ON BIODEGRADABLE PLASTICS

EPA Science Inventory

Packaging is one of the largest market segments for the polymer industry. Food packaging industry is currently dominated by crude oil-derived, non-biodegradable polyolefin and polyesters. Due to their environmental persistence (non-biodegradability) leading to accumulatio...

Fluctuations of dissolved organic matter in river used for drinking water and impacts on conventional treatment plant performance.

PubMed

Volk, Christian; Kaplan, Louis A; Robinson, Jeff; Johnson, Bruce; Wood, Larry; Zhu, Hai Wei; LeChevallier, Mark

2005-06-01

Natural organic matter (NOM) in drinking water supplies can provide precursors for disinfectant byproducts, molecules that impact taste and odors, compounds that influence the efficacy of treatment, and other compounds that are a source of energy and carbon for the regrowth of microorganisms during distribution. NOM, measured as dissolved organic carbon (DOC), was monitored daily in the White River and the Indiana-American water treatment plant over 22 months. Other parameters were either measured daily (UV-absorbance, alkalinity, color, temperature) or continuously (turbidity, pH, and discharge) and used with stepwise linear regressions to predict DOC concentrations. The predictive models were validated with monthly samples of the river water and treatment plant effluent taken over a 2-year period after the daily monitoring had ended. Biodegradable DOC (BDOC) concentrations were measured in the river water and plant effluent twice monthly for 18 months. The BDOC measurements, along with measurements of humic and carbohydrate constituents within the DOC and BDOC pools, revealed that carbohydrates were the organic fraction with the highest percent removal during treatment, followed by BDOC, humic substances, and refractory DOC.

Biodegradation and flushing of MBT wastes

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

Siddiqui, A.A., E-mail: aasiddiqui.cv@amu.ac.in; Richards, D.J.; Powrie, W.

Highlights: • Stabilization was achieved for MBT wastes of different degrees of pretreatment. • About 92% reduction in the gas generation compared with raw MSW. • Pretreatment resulted in reduced TOC, nitrogen and heavy metals in leachate. • A large proportion of carbon and nitrogen remained in the waste material. - Abstract: Mechanical–biological treatment (MBT) processes are increasingly being adopted as a means of diverting biodegradable municipal waste (BMW) from landfill, for example to comply with the EU Landfill Directive. However, there is considerable uncertainty concerning the residual pollution potential of such wastes. This paper presents the results of laboratorymore » experiments on two different MBT waste residues, carried out to investigate the remaining potential for the generation of greenhouse gases and the flushing of contaminants from these materials when landfilled. The potential for gas generation was found to be between 8% and 20% of that for raw MSW. Pretreatment of the waste reduced the potential for the release of organic carbon, ammoniacal nitrogen, and heavy metal contents into the leachate; and reduced the residual carbon remaining in the waste after final degradation from ∼320 g/kg dry matter for raw MSW to between 183 and 195 g/kg dry matter for the MBT wastes.« less

Subcritical water extraction of organic matter from sedimentary rocks.

PubMed

Luong, Duy; Sephton, Mark A; Watson, Jonathan S

2015-06-16

Subcritical water extraction of organic matter containing sedimentary rocks at 300°C and 1500 psi produces extracts comparable to conventional solvent extraction. Subcritical water extraction of previously solvent extracted samples confirms that high molecular weight organic matter (kerogen) degradation is not occurring and that only low molecular weight organic matter (free compounds) are being accessed in analogy to solvent extraction procedures. The sedimentary rocks chosen for extraction span the classic geochemical organic matter types. A type I organic matter-containing sedimentary rock produces n-alkanes and isoprenoidal hydrocarbons at 300°C and 1500 psi that indicate an algal source for the organic matter. Extraction of a rock containing type II organic matter at the same temperature and pressure produces aliphatic hydrocarbons but also aromatic compounds reflecting the increased contributions from terrestrial organic matter in this sample. A type III organic matter-containing sample produces a range of non-polar and polar compounds including polycyclic aromatic hydrocarbons and oxygenated aromatic compounds at 300°C and 1500 psi reflecting a dominantly terrestrial origin for the organic materials. Although extraction at 300°C and 1500 psi produces extracts that are comparable to solvent extraction, lower temperature steps display differences related to organic solubility. The type I organic matter produces no products below 300°C and 1500 psi, reflecting its dominantly aliphatic character, while type II and type III organic matter contribute some polar components to the lower temperature steps, reflecting the chemical heterogeneity of their organic inventory. The separation of polar and non-polar organic compounds by using different temperatures provides the potential for selective extraction that may obviate the need for subsequent preparative chromatography steps. Our results indicate that subcritical water extraction can act as a suitable replacement for conventional solvent extraction of sedimentary rocks, but can also be used for any organic matter containing mineral matrix, including soils and recent sediments, and has the added benefit of tailored extraction for analytes of specific polarities. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

[Local foreign body reactions to biodegradable implants. A classification].

PubMed

Hoffmann, R; Weller, A; Helling, H J; Krettek, C; Rehm, K E

1997-08-01

Biodegradable implants are increasingly used in orthopedic and trauma surgery. Many different implants consisting of different biodegradable polymers are currently available. Different factors contribute to the biocompatibility of these implants, and local foreign-body reactions remain a matter of concern. Therefore, it is mandatory to document and compare the tissue reactions caused by various biodegradable implants in experimental or clinical studies. We have developed a standardized system of classification based on our previous experimental and clinical observations. Foreign-body reactions are differentiated into osteolysis (0-0 to 0-4), extra-articular (EA-0 to EA-4) and intraarticular (IA-0 to A-4) soft-tissue reactions.

Study of Methanogenesis while Bioutilisation of Plant Residuals

NASA Astrophysics Data System (ADS)

Ilyin, V. K.; Korniushenkova, I. N.; Starkova, L. V.; Lauriniavichius, K. S.

respect principals of planet ecology, and compatibility with other habitability systems. For these purpose the waste management technologies, relevant to application of the biodegradation properties of bacteria are of great value. Biological treatment method is based upon the biodegradation of organic substances by various microorganisms. vegetable non-edible residual, using artificial inoculum; to study peculiarities of biogas, possibilities to optimize or to reduce the share of methane. fermentation. The biogas production achieved 46 l per 1 kg of substrate. The microbial studies of biodegradation process revealed following peculiarities: (i)gradual quantitative increasing of Lactobacillus sp. (from 103 to 105 colony forming units (CFU) per ml); (ii)activation of Clostridia sp. (from 102 to 104 CFU/ml); (iii) elimination of aerobic conventional pathogens (Enterobacteriaceae sp., Protea sp., staphylococci). methane content measures revealed traces 0.1-0.4%. granules, the amount of methane in biogas reached 80-90%. biodegradation of vegetable wastes. This inoculum consists of active sludge adapted to wastes mixed with excretes of insects which consume plant wastes. Using this inoculum the biodegradation process takes less time, then that using active sludge. Regulation of methane concentration from traces to 90% may be achieved by adding of methane reactor to the plant digester.

Improvement of Landfill Leachate Biodegradability with Ultrasonic Process

PubMed Central

Mahvi, Amir Hossein; Roodbari, Ali Akbar; Nabizadeh Nodehi, Ramin; Nasseri, Simin; Dehghani, Mohammad Hadil; Alimohammadi, Mahmood

2012-01-01

Landfills leachates are known to contain recalcitrant and/or non-biodegradable organic substances and biological processes are not efficient in these cases. A promising alternative to complete oxidation of biorecalcitrant leachate is the use of ultrasonic process as pre-treatment to convert initially biorecalcitrant compounds to more readily biodegradable intermediates. The objectives of this study are to investigate the effect of ultrasonic process on biodegradability improvement. After the optimization by factorial design, the ultrasonic were applied in the treatment of raw leachates using a batch wise mode. For this, different scenarios were tested with regard to power intensities of 70 and 110 W, frequencies of 30, 45 and 60 KHz, reaction times of 30, 60, 90 and 120 minutes and pH of 3, 7 and 10. For determining the effects of catalysts on sonication efficiencies, 5 mg/l of TiO2 and ZnO have been also used. Results showed that when applied as relatively brief pre-treatment systems, the sonocatalysis processes induce several modifications of the matrix, which results in significant enhancement of its biodegradability. For this reason, the integrated chemical–biological systems proposed here represent a suitable solution for the treatment of landfill leachate samples. PMID:22829863

40 CFR 264.1082 - Standards: General.

Code of Federal Regulations, 2011 CFR

2011-07-01

... process is equal to or greater than 95 percent, and the organic biodegradation efficiency (Rbio) for the... biodegradation efficiency for the process shall be determined using the procedures specified in § 264.1083(b) of this subpart. (B) The total actual organic mass biodegradation rate (MRbio) for all hazardous waste...

40 CFR 265.1083 - Standards: General.

Code of Federal Regulations, 2013 CFR

2013-07-01

... process is equal to or greater than 95 percent, and the organic biodegradation efficiency (Rbio) for the... biodegradation efficiency for the process shall be determined using the procedures specified in § 265.1084(b) of this subpart. (B) The total actual organic mass biodegradation rate (MRbio) for all hazardous waste...

40 CFR 264.1082 - Standards: General.

Code of Federal Regulations, 2010 CFR

2010-07-01

... process is equal to or greater than 95 percent, and the organic biodegradation efficiency (Rbio) for the... biodegradation efficiency for the process shall be determined using the procedures specified in § 264.1083(b) of this subpart. (B) The total actual organic mass biodegradation rate (MRbio) for all hazardous waste...

40 CFR 265.1083 - Standards: General.

Code of Federal Regulations, 2012 CFR

2012-07-01

... process is equal to or greater than 95 percent, and the organic biodegradation efficiency (Rbio) for the... biodegradation efficiency for the process shall be determined using the procedures specified in § 265.1084(b) of this subpart. (B) The total actual organic mass biodegradation rate (MRbio) for all hazardous waste...

40 CFR 264.1082 - Standards: General.

Code of Federal Regulations, 2014 CFR

2014-07-01

... process is equal to or greater than 95 percent, and the organic biodegradation efficiency (Rbio) for the... biodegradation efficiency for the process shall be determined using the procedures specified in § 264.1083(b) of this subpart. (B) The total actual organic mass biodegradation rate (MRbio) for all hazardous waste...

40 CFR 265.1083 - Standards: General.

Code of Federal Regulations, 2010 CFR

2010-07-01

... process is equal to or greater than 95 percent, and the organic biodegradation efficiency (Rbio) for the... biodegradation efficiency for the process shall be determined using the procedures specified in § 265.1084(b) of this subpart. (B) The total actual organic mass biodegradation rate (MRbio) for all hazardous waste...

40 CFR 264.1082 - Standards: General.

Code of Federal Regulations, 2012 CFR

2012-07-01

... process is equal to or greater than 95 percent, and the organic biodegradation efficiency (Rbio) for the... biodegradation efficiency for the process shall be determined using the procedures specified in § 264.1083(b) of this subpart. (B) The total actual organic mass biodegradation rate (MRbio) for all hazardous waste...

40 CFR 265.1083 - Standards: General.

Code of Federal Regulations, 2011 CFR

2011-07-01

... process is equal to or greater than 95 percent, and the organic biodegradation efficiency (Rbio) for the... biodegradation efficiency for the process shall be determined using the procedures specified in § 265.1084(b) of this subpart. (B) The total actual organic mass biodegradation rate (MRbio) for all hazardous waste...

40 CFR 265.1083 - Standards: General.

Code of Federal Regulations, 2014 CFR

2014-07-01

... process is equal to or greater than 95 percent, and the organic biodegradation efficiency (Rbio) for the... biodegradation efficiency for the process shall be determined using the procedures specified in § 265.1084(b) of this subpart. (B) The total actual organic mass biodegradation rate (MRbio) for all hazardous waste...

40 CFR 264.1082 - Standards: General.

Code of Federal Regulations, 2013 CFR

2013-07-01

... process is equal to or greater than 95 percent, and the organic biodegradation efficiency (Rbio) for the... biodegradation efficiency for the process shall be determined using the procedures specified in § 264.1083(b) of this subpart. (B) The total actual organic mass biodegradation rate (MRbio) for all hazardous waste...

Geobacteraceae Community Composition Is Related to Hydrochemistry and Biodegradation in an Iron-Reducing Aquifer Polluted by a Neighboring Landfill†

PubMed Central

Lin, Bin; Braster, Martin; van Breukelen, Boris M.; van Verseveld, Henk W.; Westerhoff, Hans V.; Röling, Wilfred F. M.

2005-01-01

Relationships between community composition of the iron-reducing Geobacteraceae, pollution levels, and the occurrence of biodegradation were established for an iron-reducing aquifer polluted with landfill leachate by using cultivation-independent Geobacteraceae 16S rRNA gene-targeting techniques. Numerical analysis of denaturing gradient gel electrophoresis (DGGE) profiles and sequencing revealed a high Geobacteraceae diversity and showed that community composition within the leachate plume differed considerably from that of the unpolluted aquifer. This suggests that pollution has selected for specific species out of a large pool of Geobacteraceae. DGGE profiles of polluted groundwater taken near the landfill (6- to 39-m distance) clustered together. DGGE profiles from less-polluted groundwater taken further downstream did not fall in the same cluster. Several individual DGGE bands were indicative of either the redox process or the level of pollution. This included a pollution-indicative band that dominated the DGGE profiles from groundwater samples taken close to the landfill (6 to 39 m distance). The clustering of these profiles and the dominance by a single DGGE band corresponded to the part of the aquifer where organic micropollutants and reactive dissolved organic matter were attenuated at relatively high rates. PMID:16204512

Waste-Activated Sludge Fermentation for Polyacrylamide Biodegradation Improved by Anaerobic Hydrolysis and Key Microorganisms Involved in Biological Polyacrylamide Removal.

PubMed

Dai, Xiaohu; Luo, Fan; Zhang, Dong; Dai, Lingling; Chen, Yinguang; Dong, Bin

2015-07-06

During the anaerobic digestion of dewatered sludge, polyacrylamide (PAM), a chemical conditioner, can usually be consumed as a carbon and nitrogen source along with other organic matter (e.g., proteins and carbohydrates in the sludge). However, a significant accumulation of acrylamide monomers (AMs) was observed during the PAM biodegradation process. To improve the anaerobic hydrolysis of PAM, especially the amide hydrolysis process, and to avoid the generation of the intermediate product AM, a new strategy is reported herein that uses an initial pH of 9, 200 mg COD/L of PAM and a fermentation time of 17 d. First, response surface methodology (RSM) was applied to optimize PAM removal in the anaerobic digestion of the sludge. The biological hydrolysis of PAM reached 86.64% under the optimal conditions obtained from the RSM. Then, the mechanisms for the optimized parameters that significantly improved the biological hydrolysis of PAM were investigated by the synergistic effect of the main organic compounds in the sludge, the floc size distribution, and the enzymatic activities. Finally, semi-continuous-flow experiments for a microbial community study were investigated based on the determination of key microorganisms involved in the biological hydrolysis of PAM.

Influence of organic substrates on the kinetics of bacterial As(III) oxidation

NASA Astrophysics Data System (ADS)

Lescure, T.; Joulian, C.; Bauda, P.; Hénault, C.; Battaglia-Brunet, F.

2012-04-01

Soil microflora plays a major role on the behavior of metals and metalloids. Arsenic speciation, in particular, is related to the activity of bacteria able to oxidize, reduce or methylate this element, and determines mobility, bioavailability and toxicity of As. Arsenite (AsIII) is more toxic and more mobile than arsenate (AsV). Bacterial As(III)-oxidation tends to reduce the toxicity of arsenic in soils and the risk of transfer toward underlying aquifers, that would affect the quality of water resources. Previous results suggest that organic matter may affect kinetics or efficiency of bacterial As(III)-oxidation in presence of oxygen, thus in conventional physico-chemical conditions of a surface soil. Different hypothesis can be proposed to explain the influence of organic matter on As(III) oxidation. Arsenic is a potential energy source for bacteria. The presence of easily biodegradable organic matter may inhibit the As(III) oxidation process because bacteria would first metabolize these more energetic substrates. A second hypothesis would be that, in presence of organic matter, the Ars system involved in bacterial resistance to arsenic would be more active and would compete with the Aio system of arsenite oxidation, decreasing the global As(III) oxidation rate. In addition, organic matter influences the solubility of iron oxides which often act as the main pitfalls of arsenic in soils. The concentration and nature of organic matter could therefore have a significant influence on the bioavailability of arsenic and hence on its environmental impact. The influence of organic matter on biological As(III) oxidation has not yet been determined in natural soils. In this context, soil amendment with organic matter during operations of phytostabilization or, considering diffuse pollutions, through agricultural practices, may affect the mobility and bio-availability of the toxic metalloid. The objective of the present project is to quantify the influence of organic matter on the bacterial speciation of arsenic in contaminated soils. Moreover, the biogeochemical consequences of this phenomenon on the mobility and ecotoxicity of this metalloid will be studied. The first task of this program is the precise and systematic investigation of the influence of different types and concentrations of organic matters on the activity of As(III)-oxidizing pure strains. Influence of aspartate, succinate (simple substrates) and yeast extract (complex substrate) on As(III)-oxidation kinetics has been studied. For each experiment, the bacterial growth and the expression of genes involved in the speciation of arsenic, i.e. aio and ars genes, has been monitored. A direct perspective of this work will be to perform experiments with humic and fulvic acids (complex organic matter commonly found in soils), and with water-extracted organic matter from polluted soils. Then the As(III)-oxidation activity of bacterial communities extracted from contaminated soils will be followed. These assays should allow the screening of conditions which will be applied in subsequent experiments with several real contaminated soils, including a former mining site, impacted industrial sites, and a forest soil heavily contaminated after arsenical ammunitions storage. This work is co-funded by BRGM and ADEME (convention TEZ 11-16).

Biodegradability of organic nanoparticles in the aqueous environment.

PubMed

Kümmerer, Klaus; Menz, Jakob; Schubert, Thomas; Thielemans, Wim

2011-03-01

Synthetic nanoparticles have already been detected in the aquatic environment. Therefore, knowledge on their biodegradability is of utmost importance for risk assessment but such information is currently not available. Therefore, the biodegradability of fullerenes, single, double, multi-walled as well as COOH functionalized carbon nanotubes and cellulose and starch nanocrystals in aqueous environment has been investigated according to OECD standards. The biodegradability of starch and cellulose nanoparticles was also compared with the biodegradability of their macroscopic counterparts. Fullerenes and all carbon nanotubes did not biodegrade at all, while starch and cellulose nanoparticles biodegrade to similar levels as their macroscopic counterparts. However, neither comfortably met the criterion for ready biodegradability (60% after 28 days). The cellulose and starch nanoparticles were also found to degrade faster than their macroscopic counterparts due to their higher surface area. These findings are the first report of biodegradability of organic nanoparticles in the aquatic environment, an important accumulation environment for manmade compounds. Copyright © 2010 Elsevier Ltd. All rights reserved.

Non-Destructive High-Resolution Organic Matter Record on Lake Sediment using Steady-State Solid Phase Fluorescence: Organic Matter Quality and Quantity Assessment.

NASA Astrophysics Data System (ADS)

Quiers, M.; Perrette, Y.; Etienne, D.; Develle, A. L.; Jacq, K.

2017-12-01

The use of organic proxies increases in paleoenvironmental reconstructions from natural archives. Major advances have been achieved by the development of new highly informative molecular proxies usually linked to specific compounds. While studies focused on targeted compounds, offering a high information degree, advances on bulk organic matter are limited. However, this bulk is the main contributor to carbon cycle and has been shown to be a driver of many mineral or organic compounds transfer and record. Development of target proxies need complementary information on bulk organic matter to understand biases link to controlling factors or analytical methods, and provide a robust interpretation. Fluorescence methods have often been employed to characterize and quantify organic matter. However, these technics are mainly developed for liquid samples, inducing material and resolution loss when working on natural archives (either stalagmite or sediments). High-resolution solid phase fluorescence (SPF) was developed on speleothems. This method allows now to analyse organic matter quality and quantity if procedure to constrain the optical density are adopted. In fact, a calibration method using liquid phase fluorescence (LPF) was developed for speleothem, allowing to quantify organic carbon at high-resolution. We report here an application of such a procedure SPF/LPF measurements on lake sediments. In order to avoid sediment matrix effects on the fluorescence signal, a calibration using LPF measurements was realised. First results using this method provided organic matter quality record of different organic matter compounds (humic-like, protein-like and chlorophylle-like compounds) at high resolution for the sediment core. High resolution organic matter fluxes are obtained in a second time, applying pragmatic chemometrics model (non linear models, partial least square models) on high resolution fluorescence data. SPF method can be considered as a promising tool for high resolution record on organic matter quality and quantity. Potential application of this method will be evocated (lake ecosystem dynamic, changes in trophic levels)

Organic intermediates in the anaerobic biodegradation of coal to methane under laboratory conditions

USGS Publications Warehouse

Orem, William H.; Voytek, Mary A.; Jones, Elizabeth J.; Lerch, Harry E.; Bates, Anne L.; Corum, Margo D.; Warwick, Peter D.; Clark, Arthur C.

2010-01-01

Organic intermediates in coal fluids produced by anaerobic biodegradation of geopolymers in coal play a key role in the production of methane in natural gas reservoirs. Laboratory biodegradation experiments on sub-bituminous coal from Texas, USA, were conducted using bioreactors to examine the organic intermediates relevant to methane production. Production of methane in the bioreactors was linked to acetate accumulation in bioreactor fluid. Long chain fatty acids, alkanes (C19–C36) and various low molecular weight aromatics, including phenols, also accumulated in the bioreactor fluid and appear to be the primary intermediates in the biodegradation pathway from coal-derived geopolymers to acetate and methane.

Presence, fate and effects of the intense sweetener sucralose in the aquatic environment.

PubMed

Tollefsen, Knut Erik; Nizzetto, Luca; Huggett, Duane B

2012-11-01

Sucralose (1,6-dichloro-1,6-dideoxy-b-D-fructo-furanosyl 4-chloro-4-deoxy-a-D-galactopyranoside), sold under the trade name Splenda, has been detected in municipal effluents and surface waters in the United States and Europe. The environmental presence of sucralose has led to interest in the possibility of toxic effects in non-target species. This review presents an environmental risk assessment of sucralose based on available data concerning its presence, fate and effects in the environment. Sucralose, which is made by selective chlorination of sucrose, is a highly stable compound, which undergoes negligible metabolism in mammals, including humans, and displays a low biodegradation potential in the environment. This intense sweetener is highly soluble in water, displays a low bioaccumulation potential and a low sorption potential to soil and organic matter, and thus is predominantly present in the water column. The predicted environmental concentration (PEC) for sucralose, based on measured data in surface waters, was determined to be 10 μg/L. Aquatic toxicity studies using standardized, validated protocols used in regulatory decision making indicate that sucralose does not alter survival, growth and reproduction of aquatic organisms (such as plants, algae, crustaceans and fish) at concentrations >9000 times higher than those detected in the environment. Some studies, using non-standardized protocols, have reported behavioral and other non-traditional responses in aquatic organisms, but the relevance of these findings for assessing adverse effects on individuals and populations will require further investigation. In terms of traditional risk assessment, the proposed predicted no effect concentration for aquatic organisms (PNEC) was determined to be 0.93 mg/L, based on the lowest no effect concentration (NOEC) from a validated chronic study with mysid shrimp and an application factor of 100. The resultant PEC/PNEC quotient was determined to be well below 1 (PEC/PNEC=0.08), thus indicating a limited risk to the environment using traditional ecological risk assessment approaches. Copyright © 2012 Elsevier B.V. All rights reserved.

Bacterial diversity and active biomass in full-scale granular activated carbon filters operated at low water temperatures.

PubMed

Kaarela, Outi E; Härkki, Heli A; Palmroth, Marja R T; Tuhkanen, Tuula A

2015-01-01

Granular activated carbon (GAC) filtration enhances the removal of natural organic matter and micropollutants in drinking water treatment. Microbial communities in GAC filters contribute to the removal of the biodegradable part of organic matter, and thus help to control microbial regrowth in the distribution system. Our objectives were to investigate bacterial community dynamics, identify the major bacterial groups, and determine the concentration of active bacterial biomass in full-scale GAC filters treating cold (3.7-9.5°C), physicochemically pretreated, and ozonated lake water. Three sampling rounds were conducted to study six GAC filters of different operation times and flow modes in winter, spring, and summer. Total organic carbon results indicated that both the first-step and second-step filters contributed to the removal of organic matter. Length heterogeneity analysis of amplified 16S rRNA genes illustrated that bacterial communities were diverse and considerably stable over time. α-Proteobacteria, β-Proteobacteria, and Nitrospira dominated in all of the GAC filters, although the relative proportion of dominant phylogenetic groups in individual filters differed. The active bacterial biomass accumulation, measured as adenosine triphosphate, was limited due to low temperature, low flux of nutrients, and frequent backwashing. The concentration of active bacterial biomass was not affected by the moderate seasonal temperature variation. In summary, the results provided an insight into the biological component of GAC filtration in cold water temperatures and the operational parameters affecting it.

Nanoparticles in Constanta-North Wastewater Treatment Plant

NASA Astrophysics Data System (ADS)

Panaitescu, I. M.; Panaitescu, Fanel-Viorel L.; Panaitescu, Ileana-Irina F. V.

2015-02-01

In this paper we describe the route of the nanoparticles in the WWTP and demonstrate how to use the simulation flow sensitivity analysis within STOATTM program to evaluate the effect of variation of the constant, "k" in the equation v= kCh settling on fixed concentration of nanoparticles in sewage water from a primary tank of physical-biological stage. Wastewater treatment facilities are designed to remove conventional pollutants from sanitary waste. Major processes of treatment includes: a) physical treatment-remove suspended large solids by settling or sedimentation and eliminate floating greases; b) biological treatment-degradation or consumption of the dissolved organic matter using the means of cultivated in activated sludge or the trickling filters; c) chemical treatment-remove other matters by the means of chemical addition or destroying pathogenic organisms through disinfection; d) advanced treatment- removing specific constituents using processes such as activated carbon, membrane separation, or ion exchange. Particular treatment processes are: a) sedimentation; b) coagulation and flocculation; c) activated sludge; d) sand filters; e) membrane separation; f) disinfection. Methods are: 1) using the STOATTM program with input and output data for primary tank and parameters of wastewater. 2) generating a data file for influent using a sinusoidal model and we accepted defaults STOATTM data. 3) After this, getting spreadsheet data for various characteristics of wastewater for 48 hours:flow, temperature, pH, volatile fatty acids, soluble BOD, COD inert soluble particulate BOD, COD inert particles, volatile solids, volatile solids, ammonia, nitrate and soluble organic nitrogen. Findings and Results:1.Graphics after 48 hour;. 2.Graphics for parameters - flow,temperature, pH/units hours; 3.Graphics of nanoparticles; 4. Graphics of others volatile and non-volatile solids; 5. Timeseries data and summary statistics. Biodegradation of nanoparticles is the breakdown of organic molecules that may cause changes in the physical structure or the surface characteristic of the material.

Selective Leaching of Dissolved Organic Matter From Alpine Permafrost Soils on the Qinghai-Tibetan Plateau

NASA Astrophysics Data System (ADS)

Wang, Yinghui; Xu, Yunping; Spencer, Robert G. M.; Zito, Phoebe; Kellerman, Anne; Podgorski, David; Xiao, Wenjie; Wei, Dandan; Rashid, Harunur; Yang, Yuanhe

2018-03-01

Ongoing global temperature rise has caused significant thaw and degradation of permafrost soils on the Qinghai-Tibetan Plateau (QTP). Leaching of organic matter from permafrost soils to aquatic systems is highly complex and difficult to reproduce in a laboratory setting. We collected samples from natural seeps of active and permafrost layers in an alpine swamp meadow on the QTP to shed light on the composition of mobilized dissolved organic matter (DOM) by combining optical measurements, ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry, radiocarbon (14C), and solid-state 13C nuclear magnetic resonance spectroscopy. Our results show that even though the active layer soils contain large amounts of proteins and carbohydrates, there is a selective release of aromatic components, whereas in the deep permafrost layer, carbohydrate and protein components are preferentially leached during the thawing process. Given these different chemical characteristics of mobilized DOM, we hypothesize that photomineralization contributes significantly to the loss of DOM that is leached from the seasonally thawed surface layer. However, with continued warming, biodegradation will become more important since biolabile materials such as protein and carbohydrate are preferentially released from deep-layer permafrost soils. This transition in DOM leachate source and associated chemical composition has ramifications for downstream fluvial networks on the QTP particularly in terms of processing of carbon and associated fluxes.

Response of microbial growth to orthophosphate and organic carbon influx in copper and plastic based plumbing water systems.

PubMed

Park, Se-Keun; Kim, Yeong-Kwan; Choi, Sung-Chan

2008-07-01

Consequences of orthophosphate addition for corrosion control in water distribution pipes with respect to microbial growth were investigated using batch and dynamic tests. Batch tests showed that the release of copper in either low or high organic carbon content water was decreased by 69% and 56% with addition 206 microg PO(4)-P, respectively. Dosing of orthophosphate against corrosion did not increase microbial growth potential in the water and in the biofilm in both corroded and uncorroded systems receiving tap water with a low content of organic carbon and of biodegradable organic fraction. However, in tap water having a high concentration of organic carbon from acetate addition, orthophosphate addition promoted the growth of bacteria, allowed more bacteria to assemble on corroded and uncorroded surfaces, and increased the consumption of organic carbon. Orthophosphate consumption did not exceed 1% of the amount of easily biodegradable organic carbon required for microbial growth, and the orthophosphate demand for corrosion control greatly exceeded the nutritional requirement of microbial growth. The results of the dynamic tests demonstrated that there was a significant effect of interaction between biodegradable organic carbon and orthophosphate on biofilm growth, whereby the effect of orthophosphate flux on microbial growth was dependent on the levels of biodegradable organic carbon. Controlling an easily biodegradable organic carbon would be therefore necessary to minimize the microbial growth potential induced by orthophosphate-based anticorrosion treatment.

Retardation of biodegradation of linear alkyl benzene sulphonate by a sublethal concentration of mercuric chloride

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

Misra, V.; Pandey, S.D.; Viswanathan, P.N.

1991-10-01

Environmental xenobiotics are usually classified into persistent and biodegradable ones. However, this may not be universally true, since biochemical capacity of ecosystems species may vary with species diversity and versatility. This may differ in different locations decided by geoclimatic factors. Prolonged exposure of organisms causing primary degradation to the toxic xenobiotics may lead to metabolic adaptation to survive the chemical stress. Also under multiple toxicant stress, the normal biodegrading capacity may be impaired by the effect of one toxicant on the organisms per se or on the enzymes causing degradation. If such inhibition of biodegradation occurs in ecosystems, even normallymore » biodegradable chemicals may tend to accumulate. To test this view, model experiments were conducted with LAS (Linear alkyl benzene sulphonate) a biodegradable surfactant and mercuric chloride. Since the purpose of the study was to test the degradation under natural conditions, no attempt was made to identify the micro-organisms involved.« less

Comparison of methane production potential, biodegradability, and kinetics of different organic substrates.

PubMed

Li, Yeqing; Zhang, Ruihong; Liu, Guangqing; Chen, Chang; He, Yanfeng; Liu, Xiaoying

2013-12-01

The methane production potential, biodegradability, and kinetics of a wide range of organic substrates were determined using a unified and simple method. Results showed that feedstocks that contained high energy density and easily degradable substrates exhibited high methane production potential and biodegradability. Lignocellulosic biomass with high content of fibrous compositions had low methane yield and biodegradability. Feedstocks with high lignin content (≥ 15%, on a TS basis) had low first-order rate constant (0.05-0.06 1/d) compared to others. A negative linear correlation between lignin content and experimental methane yield (or biodegradability) was found for lignocellulosic and manure wastes. This could be used as a fast method to predict the methane production potential and biodegradability of fiber-rich substrates. The findings of this study provided a database for the conversion efficiency of different organic substrates and might be useful for applications of biomethane potential assay and anaerobic digestion in the future. Copyright © 2013 Elsevier Ltd. All rights reserved.

Value added phytoremediation of metal stressed soils using phosphate solubilizing microbial consortium.

PubMed

Gupta, Pratishtha; Kumar, Vipin

2017-01-01

The presence of heavy metals in the soil is a matter of growing concern due to their toxic and non-biodegradable nature. Lack of effectiveness of various conventional methods due to economic and technical constraints resulted in the search for an eco-friendly and cost-effective biological techniques for heavy metal removal from the environment. Until now, phytoremediation has emerged as an innovative technique to address the problem. However, the efficiency of phytoremediation process is hindered under the high metal concentration conditions. Hence, phosphate solubilizing microbes (PSM) assisted phytoremediation technique is gaining more insight as it can reduce the contamination load even under elevated metal stressed conditions. These microbes convert heavy metals into soluble and bioavailable forms, which consequently facilitate phytoremediation. Several studies have reported that the use of microbial consortium for remediation is considered more effective as compared to single strain pure culture. Therefore, this review paper focuses on the current trends in research related to PSM mediated uptake of heavy metal by plants. The efficiency of PSM consortia in enhancing the phytoremediation process has also been reviewed. Moreover, the role of phosphatase enzymes in the mineralization of organic forms of phosphate in soil is further discussed. Biosurfactant mediated bioremediation of metal polluted soils is a matter of extensive research nowadays. Hence, the recent advancement of using biosurfactants in enhanced phytoremediation of metal stressed soils is also described.

Assessing the environmental availability of sulfamethoxazole and its acetylated metabolite in agricultural soils amended with compost and manure: an experimental and modeling study

NASA Astrophysics Data System (ADS)

Goulas, Anaïs; Sertillange, Nicolas; Garnier, Patricia; Dumény, Valérie; Bergheaud, Valérie; Benoit, Pierre; Haudin, Claire-Sophie

2017-04-01

The recycling of sludge compost and farmyard manure in agriculture can lead to the introduction of sulfonamide antibiotics and their acetylated metabolites into soils. The quality and the biodegradability of the exogenous organic matter (EOM) containing antibiotic residues is determinant for their environmental availability and fate in soils (Goulas et al., 2016). This study combined experimental and modeling approaches in order to: 1) assess the fraction of sulfamethoxazole (SMX) and N-acetyl-sulfamethoxazole (AcSMX) available in EOM-amended soils by using soft extractions (CaCl2, EDTA or cyclodextrin solutions) during a 28-day incubation; and 2) better understand the dynamics of sulfonamide residues in amended soils in connection with their availability and the mineralization of EOM organic matter thanks to the COP-Soil model (Geng et al. 2015). This model proposes several options to couple the biotransformation of organic pollutants (OP) with the decomposition of EOM in soil. The microbial degradation can be simulated by co-metabolism and specific-metabolism. The model also accounts for the formation of non-extractable residues (NER) via both physicochemical and microbial routes. The available fraction in both soil/EOM mixtures decreased from 56-96% and 31-63% initial 14C-activity for AcSMX and SMX, respectively, to reach 7-33% after 28 days. This high decrease in the first seven days was mainly due to the formation of NER that were more abundant in soil/manure mixtures than in the soil/compost ones. The three aqueous solutions differently extracted the available 14C-residues according to the incubation time, the EOM and the molecule. The mineralized fractions for both 14C-molecules were only 2-3% with a little more mineralization in the soil/manure mixtures than in the soil/compost. By using the COP-Soil model, the dynamics of EOM and OP were well described using parameter values specific to the organic matter mineralization, and this for the three soft extractants used. Others parameter values were common to both EOM and both sulfonamide compounds when coupling the dynamics of OP to EOM with the assumption of co-metabolism. The set of parameter values describing the pollutant fate strongly differed according to the soft extractant, confirming different mechanisms of extraction. Globally, the best OP simulations were obtained for the CaCl2-based extraction. Keywords Sulfonamides; environmental availability; recycling; organic matter; modeling References Goulas A. Haudin C.-S., Bergheaud V., Dumény V., Fehri S., Bourdat-Deschamps M, Nelieu S., Benoit P. 2016. A new extraction method to assess the environmental availability of ciprofloxacin in agricultural soil amended with exogenous organic matters. Chemosphere, 165, 460-469. Geng C., Haudin C.-S., Zhang Y., Lashermes G., Houot S., Garnier P.. 2015. Modelling the release of organic contaminants during compost decomposition in soil. Chemosphere, 119: 423-431.

Need for improvements in physical pretreatment of source-separated household food waste.

PubMed

Bernstad, A; Malmquist, L; Truedsson, C; la Cour Jansen, J

2013-03-01

The aim of the present study was to investigate the efficiency in physical pretreatment processes of source-separated solid organic household waste. The investigation of seventeen Swedish full-scale pretreatment facilities, currently receiving separately collected food waste from household for subsequent anaerobic digestion, shows that problems with the quality of produced biomass and high maintenance costs are common. Four full-scale physical pretreatment plants, three using screwpress technology and one using dispergation technology, were compared in relation to resource efficiency, losses of nitrogen and potential methane production from biodegradable matter as well as the ratio of unwanted materials in produced biomass intended for wet anaerobic digestion. Refuse generated in the processes represent 13-39% of TS in incoming wet waste. The methane yield from these fractions corresponds to 14-36Nm(3)/ton separately collected solid organic household waste. Also, 13-32% of N-tot in incoming food waste is found in refuse. Losses of both biodegradable material and nutrients were larger in the three facilities using screwpress technology compared to the facility using dispersion technology.(1) Thus, there are large potentials for increase of both the methane yield and nutrient recovery from separately collected solid organic household waste through increased efficiency in facilities for physical pretreatment. Improved pretreatment processes could thereby increase the overall environmental benefits from anaerobic digestion as a treatment alternative for solid organic household waste. Copyright © 2012 Elsevier Ltd. All rights reserved.

Leachate/domestic wastewater aerobic co-treatment: A pilot-scale study using multivariate analysis.

PubMed

Ferraz, F M; Bruni, A T; Povinelli, J; Vieira, E M

2016-01-15

Multivariate analysis was used to identify the variables affecting the performance of pilot-scale activated sludge (AS) reactors treating old leachate from a landfill and from domestic wastewater. Raw leachate was pre-treated using air stripping to partially remove the total ammoniacal nitrogen (TAN). The control AS reactor (AS-0%) was loaded only with domestic wastewater, whereas the other reactor was loaded with mixtures containing leachate at volumetric ratios of 2 and 5%. The best removal efficiencies were obtained for a ratio of 2%, as follows: 70 ± 4% for total suspended solids (TSS), 70 ± 3% for soluble chemical oxygen demand (SCOD), 70 ± 4% for dissolved organic carbon (DOC), and 51 ± 9% for the leachate slowly biodegradable organic matter (SBOM). Fourier transform infrared (FTIR) spectroscopic analysis confirmed that most of the SBOM was removed by partial biodegradation rather than dilution or adsorption of organics in the sludge. Nitrification was approximately 80% in the AS-0% and AS-2% reactors. No significant accumulation of heavy metals was observed for any of the tested volumetric ratios. Principal component analysis (PCA) and partial least squares (PLS) indicated that the data dimension could be reduced and that TAN, SCOD, DOC and nitrification efficiency were the main variables that affected the performance of the AS reactors. Copyright © 2015 Elsevier Ltd. All rights reserved.

Application of Bioelectrochemical Process (BES) for Electricity Generation and Sustainable Wastewater Treatment

NASA Astrophysics Data System (ADS)

Kim, Jung Rae

Bioelectrochemical system such as microbial fuel cells (MFCs) and microbial electrolysis cell are an emerging technology which converts biodegradable organic matter to electrical energy or hydrogen using a biofilm on the electrode as the biocatalyst. It has recently been shown that waste-to-energy technology based on MFC can treat organic contaminant in domestic or industrial wastewater and simultaneously produce electricity. The maximum power density increased up to 1kW/m3 based on reactor volume. Bioelectrochemical systems may reduce the energy consumption for wastewater treatment by replacing energy intensive aeration of present treatment systems, while generate electrical energy from waste. In addition, the biomass production in MFCs has been reported to be 10-50% of conventional wastewater treatment, leading to reduce environmental impact and disposal costs. Various electrochemically active bacteria metabolize biodegradable organic compounds then discharge electrons to an extracellular electron acceptor for bacterial respiration. These bacteria also transfer electrons to electrodes by direct electron transfer, electron mediators or shuttles, and electrically conductive nanowires. Investigation of bacterial electron transport mechanisms may improve understanding of the biomaterial involved and metabolic pathways as well as improving power from MFCs. Biofuel cell systems require interdisciplinary research ranging from electrochemistry, microbiology, material science and surface chemistry to engineering such as reactor design, operation and modelling. Collaboration within each study and integration of systems might increase the performance and feasibility of BES process for sustainable energy.

Biodegradable Polymers and Stem Cells for Bioprinting.

PubMed

Lei, Meijuan; Wang, Xiaohong

2016-04-29

It is imperative to develop organ manufacturing technologies based on the high organ failure mortality and serious donor shortage problems. As an emerging and promising technology, bioprinting has attracted more and more attention with its super precision, easy reproduction, fast manipulation and advantages in many hot research areas, such as tissue engineering, organ manufacturing, and drug screening. Basically, bioprinting technology consists of inkjet bioprinting, laser-based bioprinting and extrusion-based bioprinting techniques. Biodegradable polymers and stem cells are common printing inks. In the printed constructs, biodegradable polymers are usually used as support scaffolds, while stem cells can be engaged to differentiate into different cell/tissue types. The integration of biodegradable polymers and stem cells with the bioprinting techniques has provided huge opportunities for modern science and technologies, including tissue repair, organ transplantation and energy metabolism.

Photochemical Alternation of Phragmites australis Plant Litter: New Insight into the Chemical Evolution of Particulate Organic Matter

NASA Astrophysics Data System (ADS)

Carrasquillo, A. J.; Gelfond, C. E.; Kocar, B. D.

2015-12-01

The photolysis of natural organic matter (NOM) is a potential pathway for the alteration of material that is not easily biodegraded. Irradiation can alter the physical state of organic matter by facilitating the cycling between the particulate (POM) and dissolved (DOM) pools. However, a detailed understanding of the underlying chemical changes to the material in both phases is lacking. Here, we use a suspension of particles derived from Phragmites australis, a common marsh reed with high lignin content, as our model "recalcitrant" POM substrate. The solution was irradiated for three weeks with regular sampling, and the composition of the POM and the photo-produced DOM were measured separately using a suite of mass spectrometric and spectroscopic techniques. The chemical composition of individual molecules was measured by coupling soft ionization techniques (electrospray (ESI) and matrix assisted laser desorption (MALDI) to high-resolution mass spectrometry. Structural information, including the distribution of the major carbon containing functional groups, was obtained using a combination of FTIR for bulk analyses and scanning transmission x-ray microscopy (STXM) for spatially resolved chemistry. Results are discussed in the context of differences in chemical composition and structure with increased irradiation time for both organic matter pools. We observed a general shift in the mass spectra of POM towards lower molecular weight masses and an increase in the abundance of ions in DOM as a function of irradiation time- hence the larger POM matrix is likely fragmenting into smaller species that are more soluble. Spectroscopic measurements indicate that the abundance of acidic and alcohol functionalities increased with irradiation in both carbon pools. These complementary approaches provide new detailed information about how the chemical composition of recalcitrant NOM evolves as it is exposed to sunlight.

Anaerobic digestion of cheese whey: Energetic and nutritional potential for the dairy sector in developing countries.

PubMed

Escalante, H; Castro, L; Amaya, M P; Jaimes, L; Jaimes-Estévez, J

2018-01-01

Cheese whey (CW) is the main waste generated in the cheesemaking process and has high organic matter content and acidity. Therefore, CW disposal is a challenge for small to medium enterprises (SMEs) in the dairy industry that do not have any type of treatment plant. Anaerobic digestion (AD) is an attractive process for solving this problem. The aim of this research was to determine the biomethane and struvite precipitation potentials of CW from four dairy SMEs. First, changes in CW properties (organic matter and pH) were evaluated. Second, biomethane and struvite potentials were assessed using cattle slurry as inoculum. The organic matter in CW varied from 40 to 65gVS/kg, 65 to 140g COD/L, and 2 to 10g/L for VFAs depending on the sampling time and type of sample. The pH of the CW samples ranged from 3 to 6.5. In the anaerobic biodegradability analysis, methane yields reached 0.51 to 0.60L CH 4 /g VS added , which represented electrical and caloric potentials of 54 and 108kWh/m 3 for CW, respectively. Organic matter removal in all experiments was above 83%. Moreover, anaerobic digestates presented NH 4 + /PO 4 3- molar ratios between 2.6 and 4.0, which are adequate for struvite precipitation with potential production of 8.5-10.4g struvite/L CW. Finally, the use of biogas as energetic supplement and struvite as soil fertilizer, represents economics saves of US$ 6.91/m 3 CW and US$ 5.75/m 3 CW in therms of electricity and fertilizer use, respectively. The energetic, agricultural and economic potentials, evidence that AD process is a feasible alternative for cheese whey treatment. Copyright © 2017. Published by Elsevier Ltd.

Fluorescence spectroscopy for monitoring reduction of natural organic matter and halogenated furanone precursors by biofiltration.

PubMed

Peleato, Nicolás M; McKie, Michael; Taylor-Edmonds, Lizbeth; Andrews, Susan A; Legge, Raymond L; Andrews, Robert C

2016-06-01

The application of fluorescence spectroscopy to monitor natural organic matter (NOM) reduction as a function of biofiltration performance was investigated. This study was conducted at pilot-scale where a conventional media filter was compared to six biofilters employing varying enhancement strategies. Overall reductions of NOM were identified by measuring dissolved organic carbon (DOC), and UV absorbance at 254 nm, as well as characterization of organic sub-fractions by liquid chromatography-organic carbon detection (LC-OCD) and parallel factors analysis (PARAFAC) of fluorescence excitation-emission matrices (FEEM). The biofilter using granular activated carbon media, with exhausted absorptive capacity, was found to provide the highest removal of all identified PARAFAC components. A microbial or processed humic-like component was found to be most amenable to biodegradation by biofilters and removal by conventional treatment. One refractory humic-like component, detectable only by FEEM-PARAFAC, was not well removed by biofiltration or conventional treatment. All biofilters removed protein-like material to a high degree relative to conventional treatment. The formation potential of two halogenated furanones, 3-chloro-4(dichloromethyl)-2(5H)-furanone (MX) and mucochloric acid (MCA), as well as overall treated water genotoxicity are also reported. Using the organic characterization results possible halogenated furanone and genotoxicity precursors are identified. Comparison of FEEM-PARAFAC and LC-OCD results revealed polysaccharides as potential MX/MCA precursors. Copyright © 2016 Elsevier Ltd. All rights reserved.

Bioavailability of Heavy Metals in Soil: Impact on Microbial Biodegradation of Organic Compounds and Possible Improvement Strategies

PubMed Central

Olaniran, Ademola O.; Balgobind, Adhika; Pillay, Balakrishna

2013-01-01

Co-contamination of the environment with toxic chlorinated organic and heavy metal pollutants is one of the major problems facing industrialized nations today. Heavy metals may inhibit biodegradation of chlorinated organics by interacting with enzymes directly involved in biodegradation or those involved in general metabolism. Predictions of metal toxicity effects on organic pollutant biodegradation in co-contaminated soil and water environments is difficult since heavy metals may be present in a variety of chemical and physical forms. Recent advances in bioremediation of co-contaminated environments have focussed on the use of metal-resistant bacteria (cell and gene bioaugmentation), treatment amendments, clay minerals and chelating agents to reduce bioavailable heavy metal concentrations. Phytoremediation has also shown promise as an emerging alternative clean-up technology for co-contaminated environments. However, despite various investigations, in both aerobic and anaerobic systems, demonstrating that metal toxicity hampers the biodegradation of the organic component, a paucity of information exists in this area of research. Therefore, in this review, we discuss the problems associated with the degradation of chlorinated organics in co-contaminated environments, owing to metal toxicity and shed light on possible improvement strategies for effective bioremediation of sites co-contaminated with chlorinated organic compounds and heavy metals. PMID:23676353

Production of mono- and di-carboxylated polyethylene glycols as a factor obstacle to the successful ozonation-assisted biodegradation of ethoxylated compounds.

PubMed

Nakai, Satoshi; Okuda, Tetsuji; Nishijima, Wataru; Okada, Mitsumasa

2015-10-01

Ozonation is believed to improve the biodegradability of organic compounds. In the present study, degradation of nonylphenol ethoxylates (NPEOs) was monitored in hybrid treatment systems consisting of ozonation and microbial degradation processes. We found that ozonation of NPEOs decreased, rather than increased, the biodegradability under certain conditions. The timing of ozonation was a definitive factor in determining whether ozonation increased or decreased the biodegradation rates of NPEOs. Initial ozonation of NPEOs prior to biodegradation reduced the rate of dissolved organic carbon (DOC) removal during the subsequent 14 d of biodegradation, whereas intermediate ozonation at the 9th day of biodegradation improved subsequent DOC removal during 14 d of NPEO biodegradation. Furthermore, reduction of DOC removal was also observed, when initial ozonation prior to biodegradation was subjected to cetyl alcohol ethoxylates. The production of less biodegradable intermediates, such as mono- and dicarboxylated polyethylene glycols (MCPEGs and DCPEGs), was responsible for the negative effect of ozonation on biodegradability of NPEOs. DCPEGs and MCPEGs were produced by biodegradation of polyethylene glycols (PEGs) that were ozonolysis products of the NPEOs, and the biodegradability of DCPEGs and MCPEGs was less than that of the precursor PEGs. The results indicate that, if the target chemicals contain ethoxy chains, production of PEGs may be one of the important factors when ozonation is considered. Copyright © 2015 Elsevier Ltd. All rights reserved.

Characterization of isolated fractions of dissolved organic matter derived from municipal solid waste compost.

PubMed

Yu, Minda; He, Xiaosong; Liu, Jiaomei; Wang, Yuefeng; Xi, Beidou; Li, Dan; Zhang, Hui; Yang, Chao

2018-04-14

Understanding the heterogeneous evolution characteristics of dissolved organic matter fractions derived from compost is crucial to exploring the composting biodegradation process and the possible applications of compost products. Herein, two-dimensional correlation spectroscopy integrated with reversed-phase high performance liquid chromatography and size exclusion chromatography were utilized to obtain the molecular weight (MW) and polarity evolution characteristics of humic acid (HA), fulvic acid (FA), and the hydrophilic (HyI) fractions during composting. The high-MW humic substances and building blocks in the HA fraction degraded faster during composting than polymers, proteins, and organic colloids. Similarly, the low MW acid FA factions transformed faster than the low weight neutral fractions, followed by building blocks, and finally polymers, proteins, and organic colloids. The evolutions of HyI fractions during composting occurred first for building blocks, followed by low MW acids, and finally low weight neutrals. With the progress of composting, the hydrophobic properties of the HA and FA fractions were enhanced. The degradation/humification process of the hydrophilic and transphilic components was faster than that of the hydrophobic component. Compared with the FA and HyI fractions, the HA fraction exhibited a higher MW and increased hydrophobicity. Copyright © 2018 Elsevier B.V. All rights reserved.

Distribution and Bioconcentration of Polycyclic Aromatic Hydrocarbons in Surface Water and Fishes

PubMed Central

Li, Haiyan; Ran, Yong

2012-01-01

To examine spatial distribution and bioconcentration of PAHs, water and fish samples were collected from Pearl River Delta in summer and spring, respectively. Particulate organic carbon, dissolved organic carbon, biodegradable DOC (BDOC), and chlorophyll a were measured. PAHs were dominated by 2- and 3-ring compounds in the water and SPM samples. Aqueous and solid-phase PAHs, respectively, showed significant correlations with total organic matter (TOC) in SPM or dissolved organic matter (DOC) in the water. The in-situ partitioning coefficients (logK oc, mL/g) for the samples were observed to be related to logK ow, implying that the hydrophobicity of PAHs is a critical factor in their distribution. It was also observed that BCF increased with the increasing K ow in the viscera of tilapia (logBCF = 0.507logK ow − 1.368, r = 0.883). However, most of the observed log BCF values in other different fish tissues at first increased with the increasing of log K ow, then reached a maximum value when logK ow is between 5 and 7, and then decreased when logK ow is higher than 7, indicating that the value of BCF may vary due to the diversity of fish species. PMID:23365526

Evaluation of a new pulping technology for pre-treating source-separated organic household waste prior to anaerobic digestion.

PubMed

Naroznova, Irina; Møller, Jacob; Larsen, Bjarne; Scheutz, Charlotte

2016-04-01

A new technology for pre-treating source-separated organic household waste prior to anaerobic digestion was assessed, and its performance was compared to existing alternative pre-treatment technologies. This pre-treatment technology is based on waste pulping with water, using a specially developed screw mechanism. The pre-treatment technology rejects more than 95% (wet weight) of non-biodegradable impurities in waste collected from households and generates biopulp ready for anaerobic digestion. Overall, 84-99% of biodegradable material (on a dry weight basis) in the waste was recovered in the biopulp. The biochemical methane potential for the biopulp was 469 ± 7 mL CH4/g ash-free mass. Moreover, all Danish and European Union requirements regarding the content of hazardous substances in biomass intended for land application were fulfilled. Compared to other pre-treatment alternatives, the screw-pulping technology showed higher biodegradable material recovery, lower electricity consumption and comparable water consumption. The higher material recovery achieved with the technology was associated with greater transfer of nutrients (N and P), carbon (total and biogenic) but also heavy metals (except Pb) to the produced biomass. The data generated in this study could be used for the environmental assessment of the technology and thus help in selecting the best pre-treatment technology for source separated organic household waste. Copyright © 2016 Elsevier Ltd. All rights reserved.

Current trends in biodegradable polyhydroxyalkanoates.

PubMed

Chanprateep, Suchada

2010-12-01

The microbial polyesters known as polyhydroxyalkanoates (PHAs) positively impact global climate change scenarios by reducing the amount of non-degradable plastic used. A wide variety of different monomer compositions of PHAs has been described, as well as their future prospects for applications where high biodegradability or biocompatibility is required. PHAs can be produced from renewable raw materials and are degraded naturally by microorganisms that enable carbon dioxide and organic compound recycling in the ecosystem, providing a buffer to climate change. This review summarizes recent research on PHAs and addresses the opportunities as well as challenges for their place in the global market. Copyright © 2010 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Enhanced hydrolysis and methane yield by applying microaeration pretreatment to the anaerobic co-digestion of brown water and food waste.

PubMed

Lim, Jun Wei; Wang, Jing-Yuan

2013-04-01

Microaeration has been used conventionally for the desulphurization of biogas, and recently it was shown to be an alternative pretreatment to enhance hydrolysis of the anaerobic digestion (AD) process. Previous studies on microaeration pretreatment were limited to the study of substrates with complex organic matter, while little has been reported on its effect on substrates with higher biodegradability such as brown water and food waste. Due to the lack of consistent microaeration intensities, previous studies were not comparable and thus inconclusive in proving the effectiveness of microaeration to the overall AD process. In this study, the role of microaeration pretreatment in the anaerobic co-digestion of brown water and food waste was evaluated in batch-tests. After a 4-day pretreatment with 37.5 mL-O2/L(R)-d added to the liquid phase of the reactor, the methane production of substrates were monitored in anaerobic conditions over the next 40 days. The added oxygen was consumed fully by facultative microorganisms and a reducing environment for organic matter degradation was maintained. Other than higher COD solubilization, microaeration pretreatment led to greater VFA accumulation and the conversion of other short chain fatty acids to acetate. This could be due to enhanced activities of hydrolytic and acidogenic bacteria and the degradation of slowly biodegradable compounds under microaerobic conditions. This study also found that the nature of inoculum influenced the effects of microaeration as a 21% and 10% increase in methane yield was observed when pretreatment was applied to inoculated substrates, and substrates without inoculum, respectively. Copyright © 2012 Elsevier Ltd. All rights reserved.

Fate of the antibiotic sulfadiazine in natural soils: Experimental and numerical investigations.

PubMed

Engelhardt, Irina; Sittig, Stephan; Šimůnek, Jirka; Groeneweg, Joost; Pütz, Thomas; Vereecken, Harry

2015-01-01

Based on small-scale laboratory and field-scale lysimeter experiments, the sorption and biodegradation of sulfonamide sulfadiazine (SDZ) were investigated in unsaturated sandy and silty-clay soils. Sorption and biodegradation were low in the laboratory, while the highest leaching rates were observed when SDZ was mixed with manure. The leaching rate decreased when SDZ was mixed with pure water, and was smallest with the highest SDZ concentrations. In the laboratory, three transformation products (TPs) developed after an initial lag phase. However, the amount of TPs was different for different mixing-scenarios. The TP 2-aminopyrimidine was not observed in the laboratory, but was the most prevalent TP at the field scale. Sorption was within the same range at the laboratory and field scales. However, distinctive differences occurred with respect to biodegradation, which was higher in the field lysimeters than at the laboratory scale. While the silty-clay soil favored sorption of SDZ, the sandy, and thus highly permeable, soil was characterized by short half-lives and thus a quick biodegradation of SDZ. For 2-aminopyrimidine, half-lives of only a few days were observed. Increased field-scale biodegradation in the sandy soil resulted from a higher water and air permeability that enhanced oxygen transport and limited oxygen depletion. Furthermore, low pH was more important than the organic matter and clay content for increasing the biodegradation of SDZ. A numerical analysis of breakthrough curves of bromide, SDZ, and its TPs showed that preferential flow pathways strongly affected the solute transport within shallow parts of the soil profile at the field scale. However, this effect was reduced in deeper parts of the soil profile. Due to high field-scale biodegradation in several layers of both soils, neither SDZ nor 2-aminopyrimidine was detected in the discharge of the lysimeter at a depth of 1m. Synthetic 50 year long simulations, which considered the application of manure with SDZ for general agricultural practices in Germany and humid climate conditions, showed that the concentration of SDZ decreased below 0.1 μg/L in both soils below the depth of 50 cm. Copyright © 2015 Elsevier B.V. All rights reserved.

Fate of the antibiotic sulfadiazine in natural soils: Experimental and numerical investigations

NASA Astrophysics Data System (ADS)

Engelhardt, Irina; Sittig, Stephan; Šimůnek, Jirka; Groeneweg, Joost; Pütz, Thomas; Vereecken, Harry

2015-06-01

Based on small-scale laboratory and field-scale lysimeter experiments, the sorption and biodegradation of sulfonamide sulfadiazine (SDZ) were investigated in unsaturated sandy and silty-clay soils. Sorption and biodegradation were low in the laboratory, while the highest leaching rates were observed when SDZ was mixed with manure. The leaching rate decreased when SDZ was mixed with pure water, and was smallest with the highest SDZ concentrations. In the laboratory, three transformation products (TPs) developed after an initial lag phase. However, the amount of TPs was different for different mixing-scenarios. The TP 2-aminopyrimidine was not observed in the laboratory, but was the most prevalent TP at the field scale. Sorption was within the same range at the laboratory and field scales. However, distinctive differences occurred with respect to biodegradation, which was higher in the field lysimeters than at the laboratory scale. While the silty-clay soil favored sorption of SDZ, the sandy, and thus highly permeable, soil was characterized by short half-lives and thus a quick biodegradation of SDZ. For 2-aminopyrimidine, half-lives of only a few days were observed. Increased field-scale biodegradation in the sandy soil resulted from a higher water and air permeability that enhanced oxygen transport and limited oxygen depletion. Furthermore, low pH was more important than the organic matter and clay content for increasing the biodegradation of SDZ. A numerical analysis of breakthrough curves of bromide, SDZ, and its TPs showed that preferential flow pathways strongly affected the solute transport within shallow parts of the soil profile at the field scale. However, this effect was reduced in deeper parts of the soil profile. Due to high field-scale biodegradation in several layers of both soils, neither SDZ nor 2-aminopyrimidine was detected in the discharge of the lysimeter at a depth of 1 m. Synthetic 50 year long simulations, which considered the application of manure with SDZ for general agricultural practices in Germany and humid climate conditions, showed that the concentration of SDZ decreased below 0.1 μg/L in both soils below the depth of 50 cm.

Organic pollutant loading and biodegradability of firefighting foam

NASA Astrophysics Data System (ADS)

Zhang, Xian-Zhong; Bao, Zhi-ming; Hu, Cheng; Li-Shuai, Jing; Chen, Yang

2017-11-01

Firefighting foam has been widely used as the high-performance extinguishing agent in extinguishing the liquid poor fire. It was concerned for its environmental impacts due to its massive usage. In this study, the organic loading level and the biodegradability of 18 firefighting foams commonly used in China were evaluated and compared. The COD and TOC of firefighting foam concentrates are extremely high. Furthermore, those of foam solutions are also much higher than regular wastewater. The COD/TOC ratio of synthetic foams are higher than protein foams. The 28-day biodegradation rates of 18 firefighting foams are all over 60%, indicating that they are all ready biodegradable. Protein foams (P, FP and FFFP) have the higher organic loading and lower 28-day biodegradation rates compared to the synthetic foams (Class A foam, AFFF and S). The short and long-term impact of protein foams on the environment are larger than synthetic foams.

Deformation behaviors of peat with influence of organic matter.

PubMed

Yang, Min; Liu, Kan

2016-01-01

Peat is a kind of special material rich in organic matter. Because of the high content of organic matter, it shows different deformation behaviors from conventional geotechnical materials. Peat grain has a non-negligible compressibility due to the presence of organic matter. Biogas can generate from peat and can be trapped in form of gas bubbles. Considering the natural properties of peat, a special three-phase composition of peat is described which indicates the existence of organic matter and gas bubbles in peat. A stress-strain-time model is proposed for the compression of organic matter, and the surface tension effect is considered in the compression model of gas bubbles. Finally, a mathematical model has been developed to simulate the deformation behavior of peat considering the compressibility of organic matter and entrapped gas bubbles. The deformation process is the coupling of volume variation of organic matter, gas bubbles and water drainage. The proposed model is used to simulate a series of peat laboratory oedometer tests, and the model can well capture the test results with reasonable model parameters. Effects of model parameters on deformation of peat are also analyzed.

40 CFR 268.42 - Treatment standards expressed as specified technologies.

Code of Federal Regulations, 2014 CFR

2014-07-01

... thereby reducing potential emissions of elemental mercury vapors to the air. BIODG: Biodegradation of...., Total Organic Carbon can often be used as an indicator parameter for the biodegradation of many organic...

40 CFR 268.42 - Treatment standards expressed as specified technologies.

Code of Federal Regulations, 2013 CFR

2013-07-01

... thereby reducing potential emissions of elemental mercury vapors to the air. BIODG: Biodegradation of...., Total Organic Carbon can often be used as an indicator parameter for the biodegradation of many organic...

40 CFR 268.42 - Treatment standards expressed as specified technologies.

Code of Federal Regulations, 2012 CFR

2012-07-01

... thereby reducing potential emissions of elemental mercury vapors to the air. BIODG: Biodegradation of...., Total Organic Carbon can often be used as an indicator parameter for the biodegradation of many organic...

Biochemical interpretation of quantitative structure-activity relationships (QSAR) for biodegradation of N-heterocycles: a complementary approach to predict biodegradability.

PubMed

Philipp, Bodo; Hoff, Malte; Germa, Florence; Schink, Bernhard; Beimborn, Dieter; Mersch-Sundermann, Volker

2007-02-15

Prediction of the biodegradability of organic compounds is an ecologically desirable and economically feasible tool for estimating the environmental fate of chemicals. We combined quantitative structure-activity relationships (QSAR) with the systematic collection of biochemical knowledge to establish rules for the prediction of aerobic biodegradation of N-heterocycles. Validated biodegradation data of 194 N-heterocyclic compounds were analyzed using the MULTICASE-method which delivered two QSAR models based on 17 activating (OSAR 1) and on 16 inactivating molecular fragments (GSAR 2), which were statistically significantly linked to efficient or poor biodegradability, respectively. The percentages of correct classifications were over 99% for both models, and cross-validation resulted in 67.9% (GSAR 1) and 70.4% (OSAR 2) correct predictions. Biochemical interpretation of the activating and inactivating characteristics of the molecular fragments delivered plausible mechanistic interpretations and enabled us to establish the following biodegradation rules: (1) Target sites for amidohydrolases and for cytochrome P450 monooxygenases enhance biodegradation of nonaromatic N-heterocycles. (2) Target sites for molybdenum hydroxylases enhance biodegradation of aromatic N-heterocycles. (3) Target sites for hydratation by an urocanase-like mechanism enhance biodegradation of imidazoles. Our complementary approach represents a feasible strategy for generating concrete rules for the prediction of biodegradability of organic compounds.

Various causes behind the desorption hysteresis of carboxylic acids on mudstones.

PubMed

Rasamimanana, S; Lefèvre, G; Dagnelie, R V H

2017-02-01

Adsorption desorption is a key factor for leaching, migration and (bio)degradation of organic pollutants in soils and sediments. Desorption hysteresis of apolar organic compounds is known to be correlated with adsorption/diffusion into soil organic matter. This work focuses on the desorption hysteresis of polar organic compounds on a natural mudstone sample. Acetic, citric and ortho-phthalic acids displayed adsorption-desorption hysteresis on Callovo-Oxfordian mudstone. The non-reversible behaviours resulted from three different mechanisms. Adsorption and desorption kinetics were evaluated using 14C- and 3H-labelled tracers and an isotopic exchange method. The solid-liquid distribution ratio of acetate decreased using a NaN 3 bactericide, indicating a rapid bacterial consumption compared with negligible adsorption. The desorption hysteresis of phthalate was apparent and suppressed by the equilibration of renewal pore water with mudstone. This confirms the significant and reversible adsorption of phthalate. Finally, persistent desorption hysteresis was evidenced for citrate. In this case, a third mechanism should be considered, such as the incorporation of citrate in the solid or a chemical perturbation, leading to strong desorption resilience. The results highlighted the different pathways that polar organic pollutants might encounter in a similar environment. Data on phthalic acid is useful to predict the retarded transport of phthalate esters and amines degradation products in sediments. The behaviour of citric acid is representative of polydentate chelating agents used in ore and remediation industries. The impact of irreversible adsorption on solid/solution partitioning and transport deserves further investigation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Study of the degradation in aqueous solution of a refractory organic compound: avermectin type used as pesticide in agriculture.

PubMed

Boukhrissa, Athir; Ferrag-Siagh, Fatiha; Rouidi, Lina-Mounia; Chemat, Smaïn; Aït-Amar, Hamid

2017-10-01

We examined the removal of abamectin by the electro-Fenton (EF) process and the feasibility of biological treatment after degradation. The effect of the operating parameters showed that abamectin (Aba) degradation was enhanced with increasing temperature. Response surface analysis of the central composite design led to the following optimal conditions for the abatement of chemical oxygen demand: 45.5 °C, 5 mg L -1 , 150 mA, and 0.15 mmol L -1 for the temperature, initial Aba concentration, current intensity, and catalyst concentration, respectively. Under these conditions, 68.01% of the organic matter was removed and 94% of Aba was degraded after 5 h and 20 min of electrolysis, respectively. A biodegradability test, which was performed on a solution electrolyzed at 47 °C, 9 mg L -1 , 150 mA, and 0.15 mmol L -1 , confirms that the ratio of biological oxygen demand/chemical oxygen demand increased appreciably from 0.0584 to 0.64 after 5 h of electrolysis. This increased ratio is slightly above the limit of biodegradability (0.4). These results show the relevance of the EF process and its effectiveness for abamectin degradation. We conclude that biological treatment can be combined with the EF process for total mineralization.

Waste-Activated Sludge Fermentation for Polyacrylamide Biodegradation Improved by Anaerobic Hydrolysis and Key Microorganisms Involved in Biological Polyacrylamide Removal

PubMed Central

Dai, Xiaohu; Luo, Fan; Zhang, Dong; Dai, Lingling; Chen, Yinguang; Dong, Bin

2015-01-01

During the anaerobic digestion of dewatered sludge, polyacrylamide (PAM), a chemical conditioner, can usually be consumed as a carbon and nitrogen source along with other organic matter (e.g., proteins and carbohydrates in the sludge). However, a significant accumulation of acrylamide monomers (AMs) was observed during the PAM biodegradation process. To improve the anaerobic hydrolysis of PAM, especially the amide hydrolysis process, and to avoid the generation of the intermediate product AM, a new strategy is reported herein that uses an initial pH of 9, 200 mg COD/L of PAM and a fermentation time of 17 d. First, response surface methodology (RSM) was applied to optimize PAM removal in the anaerobic digestion of the sludge. The biological hydrolysis of PAM reached 86.64% under the optimal conditions obtained from the RSM. Then, the mechanisms for the optimized parameters that significantly improved the biological hydrolysis of PAM were investigated by the synergistic effect of the main organic compounds in the sludge, the floc size distribution, and the enzymatic activities. Finally, semi-continuous-flow experiments for a microbial community study were investigated based on the determination of key microorganisms involved in the biological hydrolysis of PAM. PMID:26144551

[Bioremediation of oil-polluted soils: using the [13C]/[12C] ratio to characterize microbial products of oil hydrocarbon biodegradation].

PubMed

Ziakun, A M; Brodskiĭ, E S; Baskunov, B P; Zakharchenko, V N; Peshenko, V P; Filonov, A E; Vetrova, A A; Ivanova, A A; Boronin, A M

2014-01-01

We compared data on the extent of bioremediation in soils polluted with oil. The data were obtained using conventional methods of hydrocarbon determination: extraction gas chromatography-mass spectrometry, extraction IR spectroscopy, and extraction gravimetry. Due to differences in the relative abundances of the stable carbon isotopes (13C/12C) in oil and in soil organic matter, these ratios could be used as natural isotopic labels of either substance. Extraction gravimetry in combination with characteristics of the carbon isotope composition of organic products in the soil before and after bioremediation was shown to be the most informative approach to an evaluation of soil bioremediation. At present, it is the only method enabling quantification of the total petroleum hydrocarbons in oil-polluted soil, as well as of the amounts of hydrocarbons remaining after bioremediation and those microbially transformed into organic products and biomass.

Incorporation of electrochemical advanced oxidation processes in a multistage treatment system for sanitary landfill leachate.

PubMed

Moreira, Francisca C; Soler, J; Fonseca, Amélia; Saraiva, Isabel; Boaventura, Rui A R; Brillas, Enric; Vilar, Vítor J P

2015-09-15

The current study has proved the technical feasibility of including electrochemical advanced oxidation processes (EAOPs) in a multistage strategy for the remediation of a sanitary landfill leachate that embraced: (i) first biological treatment to remove the biodegradable organic fraction, oxidize ammonium and reduce alkalinity, (ii) coagulation of the bio-treated leachate to precipitate humic acids and particles, followed by separation of the clarified effluent, and (iii) oxidation of the resulting effluent by an EAOP to degrade the recalcitrant organic matter and increase its biodegradability so that a second biological process for removal of biodegradable organics and nitrogen content could be applied. The influence of current density on an UVA photoelectro-Fenton (PEF) process was firstly assessed. The oxidation ability of various EAOPs such as electro-Fenton (EF) with two distinct initial total dissolved iron concentrations ([TDI]0), PEF and solar PEF (SPEF) was further evaluated and these processes were compared with their analogous chemical ones. A detailed assessment of the two first treatment stages was made and the biodegradability enhancement during the SPEF process was determined by a Zahn-Wellens test to define the ideal organics oxidation state to stop the EAOP and apply the second biological treatment. The best current density was 200 mA cm(-2) for a PEF process using a BDD anode, [TDI]0 of 60 mg L(-1), pH 2.8 and 20 °C. The relative oxidation ability of EAOPs increased in the order EF with 12 mg [TDI]0 L(-1) < EF with 60 mg [TDI]0 L(-1) < PEF with 60 mg [TDI]0 L(-1) ≤ SPEF with 60 mg [TDI]0 L(-1), using the abovementioned conditions. While EF process was much superior to the Fenton one, the superiority of PEF over photo-Fenton was less evident and SPEF attained similar degradation to solar photo-Fenton. To provide a final dissolved organic carbon (DOC) of 163 mg L(-1) to fulfill the discharge limits into the environment after a second biological process, 6.2 kJ L(-1) UV energy and 36 kWh m(-3) electrical energy were consumed using SPEF with a BDD anode at 200 mA cm(-2), 60 mg [TDI]0 L(-1), pH 2.8 and 20 °C. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Effects of Biodegradation and Photodegradation on DOM Optical Properties: Controlled Laboratory Study Using Plant, Soil and Algal Leachates

NASA Astrophysics Data System (ADS)

Hansen, A. M.; Kraus, T. E. C.; Pellerin, B. A.; Fleck, J.

2014-12-01

Many studies use optical properties to infer dissolved organic matter (DOM) composition and origin; however, there are few controlled studies which examine the effects of environmental processing on different DOM sources. Our goal was to better understand the roles DOM plays in wetland environments of the Sacramento-San Joaquin Delta. Therefore, five endmember sources of DOM from this region were selected for use in this study: peat soil (euic, thermic Typic Medisaprists); three aquatic macrophytes (white rice (Oryza sativa); tule (Schoenoplectus acutus); cattail (Typha spp.)); and one diatom (Thalassiosira weissflogii). We measured DOM concentrations (mg C/L) and optical properties (absorbance and fluorescence) of these sources following biological and photochemical degradation over a three month period. DOM concentration decreased by over 90% in plant and algal leachates following 3 months of biodegradation, while photoexposure had negligible effects. The fluorescence index (FI), humic index (HI), specific UV absorbance at 254 nm (SUVA), and carbon-normalized fluorescence of Peaks C and A increased with biodegradation, whereas Peak T decreased. Photoexposure resulted in a decrease of the FI, HI and SUVA values. Our results emphasize the need to better understand how environmental processing affects DOM properties in aquatic environments; the frequently opposing effects of biodegradation and photodegradation, which occur simultaneously in nature, make it challenging to decipher the original DOM source without considering multiple parameters. This dataset can help us better identify which optical properties, either individual or in combination, can provide insight into how biogeochemical processes affect DOM in aquatic environments.

Identification of degradation routes of metamitron in soil microcosms using 13C-isotope labeling.

PubMed

Wang, Shizong; Miltner, Anja; Nowak, Karolina M

2017-01-01

Metamitron is one of the most commonly used herbicide in sugar beet and flower bulb cultures. Numerous laboratory and field studies on sorption and degradation of metamitron were performed. Detailed biodegradation studies in soil using 13 C-isotope labeling are still missing. Therefore, we aimed at providing a detailed turnover mass balance of 13 C 6 -metamitron in soil microcosms over 80 days. In the biotic system, metamitron mineralized rapidly, and 13 CO 2 finally constituted 60% of the initial 13 C 6 -metamitron equivalents. In abiotic control experiments CO 2 rose to only 7.4% of the initial 13 C 6 -metamitron equivalents. The 13 C label from 13 C 6 -metamitron was incorporated into microbial amino acids that were ultimately stabilized in the soil organic matter forming presumably harmless biogenic residues. Finally, 13 C label from 13 C 6 -metamitron was distributed between the 13 CO 2 and the 13 C-biogenic residues indicating nearly complete biodegradation. The parallel increase of 13 C-alanine, 13 C-glutamate and 13 CO 2 indicates that metamitron was initially biodegraded via the desamino-metamitron route suggesting its relevance in the growth metabolism. In later phases of biodegradation, the "Rhodococcus route" was indicated by the low 13 CO 2 evolution and the high relevance of the pyruvate pathway, which aims at biomolecule synthesis and seems to be related to starvation. This is a first report on the detailed degradation route of metamitron in soil. Copyright © 2016 Elsevier Ltd. All rights reserved.

Organic matter variations in transgressive and regressive shales

USGS Publications Warehouse

Pasley, M.A.; Gregory, W.A.; Hart, G.F.

1991-01-01

Organic matter in the Upper Cretaceous Mancos Shale adjacent to the Tocito Sandstone in the San Juan Basin of New Mexico was characterized using organic petrology and organic geochemistry. Differences in the organic matter found in these regressive and transgressive offshore marine sediments have been documented and assessed within a sequence stratigraphic framework. The regressive Lower Mancos Shale below the Tocito Sandstone contains abundant well preserved phytoclasts and correspondingly low hydrogen indices. Total organic carbon values for the regressive shale are low. Sediments from the transgressive systems tract (Tocito Sandstone and overlying Upper Mancos Shale) contain less terrestrially derived organic matter, more amorphous non-structured protistoclasts, higher hydrogen indices and more total organic carbon. Advanced stages of degradation are characteristic of the phytoclasts found in the transgressive shale. Amorphous material in the transgressive shale fluoresces strongly while that found in the regressive shale is typically non-fluorescent. Data from pyrolysis-gas chromatography confirm these observations. These differences are apparently related to the contrasting depositional styles that were active on the shelf during regression and subsequent transgression. It is suggested that data from organic petrology and organic geochemistry provide greater resolution in sedimentologic and stratigraphic interpretations, particularly when working with basinward, fine-grained sediments. Petroleum source potential for the regressive Lower Mancos Shale below the Tocito Sandstone is poor. Based on abundant fluorescent amorphous material, high hydrogen indices, and high total organic carbon, the transgressive Upper Mancos Shale above the Tocito Sandstone possesses excellent source potential. This suggests that appreciable source potential can be found in offshore, fine-grained sediments of the transgressive systems tract below the condensed section and associated downlap surface. Organic petrology can be used to accurately predict petroleum source potential. The addition of simple fluorescence microscopy greatly enhances this predictive ability because non-generative amorphous material is generally non-fluorescent. Organic petrology must also be used to properly evaluate the utility of Tmax from programmed pyrolysis as a thermal maturity indicator. Organic matter dominated by autochthonous amorphous protistoclasts exhibits lower Tmax values than that which is composed of mostly phytoclasts. ?? 1991.

Molecularly organic/inorganic hybrid hollow mesoporous organosilica nanocapsules with tumor-specific biodegradability and enhanced chemotherapeutic functionality.

PubMed

Huang, Ping; Chen, Yu; Lin, Han; Yu, Luodan; Zhang, Linlin; Wang, Liying; Zhu, Yufang; Shi, Jianlin

2017-05-01

Based on the intrinsic features of high stability and unique multifunctionality, inorganic nanoparticles have shown remarkable potentials in combating cancer, but their biodegradability and biocompatibility are still under debate. As a paradigm, this work successfully demonstrates that framework organic-inorganic hybridization can endow the inorganic mesoporous silica nanocarriers with unique tumor-sensitive biodegradability and high biocompatibility. Based on a "chemical homology" mechanism, molecularly organic-inorganic hybridized hollow mesoporous organosilica nanocapsules (HMONs) with high dispersity and sub-50 nm particle dimension were constructed in mass production. A physiologically active disulfide bond (SS) was directly incorporated into the silica framework, which could break up upon contacting the reducing microenvironment of tumor tissue and biodegrade accordingly. Such a tumor-specific biodegradability is also responsible for the tumor-responsive drug releasing by the fast biodegradation and disintegration of the framework. The ultrasmall particle size of HMONs guarantees their high accumulation into tumor tissue, thus causing the high chemotherapeutic outcome. This research provides a paradigm that framework organic-inorganic hybridization can endow the inorganic nanocarrier with unique biological effects suitable for biomedical application, benefiting the development of novel nanosystems with the unique bio-functionality and performance. Copyright © 2017 Elsevier Ltd. All rights reserved.

BIODEGRADATION DURING CONTAMINANT TRANSPORT IN POROUS MEDIA. 3. APPARENT CONDITION-DEPENDENCY OF GROWTH-RELATED COEFFICIENTS. (R825415)

EPA Science Inventory

Abstract

The biodegradation of organic contaminants in the subsurface has become a major focus of attention, in part, due to the tremendous interest in applying in situ biodegradation and natural attenuation approaches for site remediation. The biodegradation and trans...

BIODEGRADATION DURING CONTAMINANT TRANSPORT IN POROUS MEDIA: 1. MATHEMATICAL ANALYSIS OF CONTROLLING FACTORS. (R825415)

EPA Science Inventory

Abstract

Interest in coupled biodegradation and transport of organic contaminants has expanded greatly in the past several years. In a system in which biodegradation is coupled with solute transport, the magnitude and rate of biodegradation is influenced not only by pr...

Formulation of microbial cocktails for BTEX biodegradation.

PubMed

Nagarajan, Karthiga; Loh, Kai-Chee

2015-02-01

BTEX biodegradation by a mixed community of micro-organisms offers a promising approach in terms of cost-effectiveness and elimination of secondary pollution. Two bacterial strains, Pseudomonas putida F1 and Pseudomonas stutzeri OX1 were chosen to formulate synthetic consortia based on their ability to biodegrade the mono-aromatic compounds. Benzene and toluene supported the growth of both the strains; while ethyl benzene and o-xylene were only utilized as growth substrates by P. putida F1 and P. stutzeri OX1, respectively. In a mixed substrate system, P. putida F1 exhibited incomplete removal of o-xylene while P. stutzeri OX1 displayed cometabolic removal of ethyl benzene with dark coloration of the growth medium. The biodegradation potential of the two Pseudomonas species complemented each other and offered opportunities to explore their performance as a co-culture for enhanced BTEX biodegradation. Several microbial formulations were concocted and their BTEX biodegradation characteristics were evaluated. Mixed culture biodegradation ascertained the advantages of the co-culture over the individual Pseudomonas species. This study also emphasized the significance of inoculum density and species proportion while concocting preselected micro-organisms for enhanced BTEX biodegradation.

Advances in Biodegradation of Multiple Volatile Organic Compounds

NASA Astrophysics Data System (ADS)

Zhang, M.; Yoshikawa, M.

2017-12-01

Bioremediation of soil and groundwater containing multiple contaminants remains a challenge in environmental science and engineering because complete biodegradation of all components is necessary but very difficult to accomplish in practice. This presentation provides a brief overview on advances in biodegradation of multiple volatile organic compounds (VOCs) including chlorinated ethylenes, benzene, toluene and dichloromethane (DCM). Case studies on aerobic biodegradation of benzene, toluene and DCM, and integrated anaerobic-aerobic biodegradation of 7 contaminants, specifically, tetrachloroethylene (PCE), trichloroethylene (TCE), cis-dichloroethylene (cis-DCE), vinyl chloride (VC), DCM, benzene and toluene will be provided. Recent findings based on systematic laboratory experiments indicated that aerobic toluene degradation can be enhanced by co-existence of benzene. Propioniferax, not a known benzene, toluene and DCM degrader can be a key microorganism that involves in biodegradation when the three contaminants co-exist. Integrated anaerobic-aerobic biodegradation is capable of completely degrading the seven VOCs with initial concentrations less than 30 mg/L. Dehalococcoides sp., generally considered sensitive to oxygen, can survive aerobic conditions for at least 28 days, and can be activated during the subsequent anaerobic biodegradation. This presentation may provide a systematic information about biodegradation of multiple VOCs, and a scientific basis for the complete bioremediation of multiple contaminants in situ.

Dual Effect of Manganese Oxide Micromotors: Catalytic Degradation and Adsorptive Bubble Separation of Organic Pollutants.

PubMed

Wani, Owies M; Safdar, Muhammad; Kinnunen, Niko; Jänis, Janne

2016-01-22

Manganese oxide (MnO2 ) based micromotors exhibiting a dual effect, that is, catalytic degradation and adsorptive bubble separation, were employed for water remediation. The dual effect of MnO2 microparticles led to a greater than 90 % of decolorization of non-biodegradable organic dyes in just 1 h, without the need for external agitation or bubble generation. These findings suggest high potential of MnO2 micromotors for decontamination of organic pollutants from wastewaters or natural water reserves. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A model framework to describe growth-linked biodegradation of trace-level pollutants in the presence of coincidental carbon substrates and microbes.

PubMed

Liu, Li; Helbling, Damian E; Kohler, Hans-Peter E; Smets, Barth F

2014-11-18

Pollutants such as pesticides and their degradation products occur ubiquitously in natural aquatic environments at trace concentrations (μg L(-1) and lower). Microbial biodegradation processes have long been known to contribute to the attenuation of pesticides in contaminated environments. However, challenges remain in developing engineered remediation strategies for pesticide-contaminated environments because the fundamental processes that regulate growth-linked biodegradation of pesticides in natural environments remain poorly understood. In this research, we developed a model framework to describe growth-linked biodegradation of pesticides at trace concentrations. We used experimental data reported in the literature or novel simulations to explore three fundamental kinetic processes in isolation. We then combine these kinetic processes into a unified model framework. The three kinetic processes described were: the growth-linked biodegradation of micropollutant at environmentally relevant concentrations; the effect of coincidental assimilable organic carbon substrates; and the effect of coincidental microbes that compete for assimilable organic carbon substrates. We used Monod kinetic models to describe substrate utilization and microbial growth rates for specific pesticide and degrader pairs. We then extended the model to include terms for utilization of assimilable organic carbon substrates by the specific degrader and coincidental microbes, growth on assimilable organic carbon substrates by the specific degrader and coincidental microbes, and endogenous metabolism. The proposed model framework enables interpretation and description of a range of experimental observations on micropollutant biodegradation. The model provides a useful tool to identify environmental conditions with respect to the occurrence of assimilable organic carbon and coincidental microbes that may result in enhanced or reduced micropollutant biodegradation.

Hydrological changes of DOM composition and biodegradability of rivers in temperate monsoon climates

NASA Astrophysics Data System (ADS)

Shin, Yera; Lee, Eun-Ju; Jeon, Young-Joon; Hur, Jin; Oh, Neung-Hwan

2016-09-01

The spatial and hydrological dynamics of dissolved organic matter (DOM) composition and biodegradability were investigated for the five largest rivers in the Republic of Korea (South Korea) during the years 2012-2013 using incubation experiments and spectroscopic measurements, which included parallel factor analysis (PARAFAC). The lower reaches of the five rivers were selected as windows showing the integrated effects of basin biogeochemistry of different land use under Asian monsoon climates, providing an insight on consistency of DOM dynamics across multiple sites which could be difficult to obtain from a study on an individual river. The mean dissolved organic carbon (DOC) concentrations of the five rivers were relatively low, ranging from 1.4 to 3.4 mg L-1, due to the high slope and low percentage of wetland cover in the basin. Terrestrial humic- and fulvic-like components were dominant in all the rivers except for one, where protein-like compounds were up to ∼80%. However, terrestrial components became dominant in all five of the rivers after high precipitation during the summer monsoon season, indicating the strong role of hydrology on riverine DOM compositions for the basins under Asian monsoon climates. Considering that 64% of South Korea is forested, our results suggest that the forests could be a large source of riverine DOM, elevating the DOM loads during monsoon rainfall. Although more DOM was degraded when DOM input increased, regardless of its sources, the percent biodegradability was reduced with increased proportions of terrestrially derived aromatic compounds. The shift in DOM quality towards higher percentages of aromatic terrestrial compounds may alter the balance of the carbon cycle of coastal ecosystems by changing microbial metabolic processes if climate extremes such as heavy storms and typhoons become more frequent due to climate change.

Adsorption studies of the herbicide simazine in agricultural soils of the Aconcagua valley, central Chile.

PubMed

Flores, Cecilia; Morgante, Verónica; González, Myriam; Navia, Rodrigo; Seeger, Michael

2009-03-01

Simazine is a s-triazine herbicide that has been applied worldwide for agriculture. This herbicide is the second most commonly detected pesticide in surface and groundwater in the United States, Europe and Australia. In this study, simazine adsorption behaviour was studied in two agricultural soils of the Aconcagua valley, central Chile. The two studied soils were soil A (loam, 8.5% organic matter content) and soil B (clay-loam, 3.5% organic matter content). Three times higher simazine adsorption capacity was observed in soil A (68.03 mg kg(-1)) compared to soil B (22.03 mg kg(-1)). The simazine adsorption distribution coefficients (K(d)) were 9.32 L kg(-1) for soil A and 7.74 L kg(-1) for soil B. The simazine adsorption enthalpy in soil A was -21.0 kJ mol(-1) while in soil B the adsorption enthalpy value was -11.5 kJ mol(-1). These results indicate that simazine adsorption process in these soils is exothermic, governing H bonds the adsorption process of simazine in both the loam and clay-loam soils. These results and the potentiometric profiles of both soils, suggest that simazine adsorption in soil A is mainly governed by simazine-organic matter interactions and in soil B by simazine-clay interactions. The understanding of simazine sorption-desorption processes is essential to determine the pesticide fate and availability in soil for pest control, biodegradation, runoff and leaching.

Microbial availability and size fractionation of dissolved organic carbon after drought in an intermittent stream: biogeochemical link across the stream-riparian interface.

PubMed

Romaní, Anna M; Vázquez, Eusebi; Butturini, Andrea

2006-10-01

The evolution of dissolved organic carbon (DOC) molecular-weight fractions, DOC biodegradability (BDOC), DOC origin [fluorescence index (FI)], and enzyme activities between the stream waters (main and ephemeral channel) and ground waters (riparian and hillslope) were analyzed during the transition from drought to precipitation in a forested Mediterranean stream. After the first rains, DOC content in stream water reached its maximum value (10-18 mg L(-1)), being explained by the leaching of deciduous leaves accumulated on the stream bed during drought. During this period, the largest molecules (>10 kDa), were the most biodegradable, as indicated by high BDOC values measured during storm events and high enzymatic activities (especially for leucine-aminopeptidase). DOC >100 kDa was strongly immobilized (78%) at the stream-riparian interface, whereas the smallest molecules (<1 kDa) were highly mobile and accumulated in ground waters, indicating their greater recalcitrance. Differential enzymatic patterns between compartments showed a fast utilization of polysaccharides in the flowing water but a major protein utilization in the ground water. The results of the FI indicated a more terrestrial origin of the larger molecules in the flowing water, also suggesting that transformation of material occurs through the stream-riparian interface. Microbial immobilization and fast utilization of the most biodegradable fraction at the stream-riparian interface is suggested as a relevant DOC retention mechanism just after initial recharging of the ground water compartment. Large and rapid DOC inputs entering the intermittent river system during the transition from drought to precipitation provide available N and C sources for the heterotrophs. Heterotrophs efficiently utilize these resources that were in limited supply during the period of drought. Such changes in C cycling may highlight possible changes in organic matter dynamics under the prediction of extended drying periods in aquatic ecosystems.

The ectomycorrhizal fungus Paxillus involutus converts organic matter in plant litter using a trimmed brown-rot mechanism involving Fenton chemistry

PubMed Central

Rineau, Francois; Roth, Doris; Shah, Firoz; Smits, Mark; Johansson, Tomas; Canbäck, Björn; Olsen, Peter Bjarke; Persson, Per; Grell, Morten Nedergaard; Lindquist, Erika; Grigoriev, Igor V; Lange, Lene; Tunlid, Anders

2012-01-01

Soils in boreal forests contain large stocks of carbon. Plants are the main source of this carbon through tissue residues and root exudates. A major part of the exudates are allocated to symbiotic ectomycorrhizal fungi. In return, the plant receives nutrients, in particular nitrogen from the mycorrhizal fungi. To capture the nitrogen, the fungi must at least partly disrupt the recalcitrant organic matter–protein complexes within which the nitrogen is embedded. This disruption process is poorly characterized. We used spectroscopic analyses and transcriptome profiling to examine the mechanism by which the ectomycorrhizal fungus Paxillus involutus degrades organic matter when acquiring nitrogen from plant litter. The fungus partially degraded polysaccharides and modified the structure of polyphenols. The observed chemical changes were consistent with a hydroxyl radical attack, involving Fenton chemistry similar to that of brown-rot fungi. The set of enzymes expressed by Pa. involutus during the degradation of the organic matter was similar to the set of enzymes involved in the oxidative degradation of wood by brown-rot fungi. However, Pa. involutus lacked transcripts encoding extracellular enzymes needed for metabolizing the released carbon. The saprotrophic activity has been reduced to a radical-based biodegradation system that can efficiently disrupt the organic matter–protein complexes and thereby mobilize the entrapped nutrients. We suggest that the released carbon then becomes available for further degradation and assimilation by commensal microbes, and that these activities have been lost in ectomycorrhizal fungi as an adaptation to symbiotic growth on host photosynthate. The interdependence of ectomycorrhizal symbionts and saprophytic microbes would provide a key link in the turnover of nutrients and carbon in forest ecosystems. PMID:22469289

Dissolved Organic Carbon in the Yukon, Tanana and Porcupine Rivers, Alaska

NASA Astrophysics Data System (ADS)

Aiken, G. R.; Striegl, R. G.; Wickland, K. P.; Dornblaser, M. M.; Raymond, P. A.

2006-12-01

The spatial and temporal variability of dissolved organic carbon (DOC) in the Yukon River (YR) and two major tributaries, the Porcupine River (PR), a black water river draining a watershed almost entirely underlain by permafrost, and the Tanana River (TR), a glacial dominated river, are being studied to better define processes controlling DOC in these systems. Five-year seasonal averages indicate DOC concentrations follow the discharge hydrograph, with highest daily and seasonal flux occurring during spring in YR and PR and during summer-autumn in TR. Largest DOC concentrations and specific UV absorption (SUVA) values, a measure of aromatic carbon content of the DOC and an indicator of DOC source, occurred at all locations during spring snowmelt. Lowest DOC concentration and SUVA occurred during low-flow in winter due to greatly reduced contributions of soil organic matter and to relatively greater influences of ground water. While all sites had comparable DOC concentration during winter, DOC concentration was greatest at PR during spring and summer-autumn, whereas TR had the lowest average DOC and SUVA values. Within the YR, average DOC concentration and SUVA values in spring and summer-autumn increase downriver due to contributions from organic carbon rich tributaries, such as PR, that increase in number and significance as the river flows through Alaska. Most the DOC in each system was comprised of hydrophobic organic acids (HPOA) derived from terrestrial vegetation. During winter, the hydrophilic fraction, determined to be the most biodegradable, was a larger percentage of the DOC than during spring-autumn. During spring, HPOA concentration and SUVA increased significantly at all sites, suggesting that most DOC in spring is derived from terrestrial organic matter that was frozen on the land surface over winter. During spring-autumn, PR had the largest concentration of HPOA and TR had the least. Like DOC concentration, HPOA concentration and SUVA increased down river. 14C-DOC values correspond to radiocarbon ages of modern (PR), 282 (TR), and 328 (YR) yrs B.P, indicating the presence of some aged DOC in YR and TR. Comparison of the chemical character of DOC from sites along the YR suggests that most DOC is transported from its source to the Bering Sea with little within river chemical or biological alteration, a result supported by laboratory biodegradation experiments.

Acute aquatic toxicity and biodegradation potential of biodiesel fuels

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

Haws, R.A.; Zhang, X.; Marshall, E.A.

1995-12-31

Recent studies on the biodegradation potential and aquatic toxicity of biodiesel fuels are reviewed. Biodegradation data were obtained using the shaker flask method observing the appearance of CO{sub 2} and by observing the disappearance of test substance with gas chromatography. Additional BOD{sub 5} and COD data were obtained. The results indicate the ready biodegradability of biodiesel fuels as well as the enhanced co-metabolic biodegradation of biodiesel and petroleum diesel fuel mixtures. The study examined reference diesel, neat soy oil, neat rape oil, and the methyl and ethyl esters of these vegetable oils as well as various fuel blends. Acute toxicitymore » tests on biodiesel fuels and blends were performed using Oncorhynchus mykiss (Rainbow Trout) in a static non-renewal system and in a proportional dilution flow replacement system. The study is intended to develop data on the acute aquatic toxicity of biodiesel fuels and blends under US EPA Good Laboratory Practice Standards. The test procedure is designed from the guidelines outlined in Methods for Measuring the Acute Toxicity of Effluents and Receiving Waters to Freshwater and Marine Organisms and the Fish Acute Aquatic Toxicity Test guideline used to develop aquatic toxicity data for substances subject to environmental effects test regulations under TSCA. The acute aquatic toxicity is estimated by an LC50, a lethal concentration effecting mortality in 50% of the test population.« less

Evaluation of the biodegradability and toxicity of landfill leachates after pretreatment using advanced oxidative processes.

PubMed

da Costa, Fabio Moraes; Daflon, Sarah Dario Alves; Bila, Daniele Maia; da Fonseca, Fabiana Valeria; Campos, Juacyara Carbonelli

2018-06-01

Leachate from urban solid waste landfills is a complex mixture of organic and inorganic substances that cause damage to the environment, due to the high concentration of recalcitrant organic matter and toxicity. The objective of this study was to apply advanced oxidation processes (AOP), namely the dark Fenton and solar photo-Fenton processes, to young and old landfill leachates prior to biological treatment. The leachates were obtained from the Seropedica and Gramacho landfill sites, respectively, located in Rio de Janeiro State, Brazil. For the two Fenton processes, different conditions of pH (1.5, 3.0 and 5.0) and Fe 2+ : H 2 O 2 ratio (1:2, 1:5 and 1:10) were evaluated. Biodegradability was evaluated using the Zahn-Wellens methodology and Aliivibrio fischeri acute toxicity tests were conducted in order to predict the toxicity in the activated sludge. The best conditions for both Fenton processes were pH of 3.0 and Fe 2+ : H 2 O 2 and COD RAW :H 2 O 2 mass ratios of 1:5 and 1:1, respectively. The solar photo-Fenton process was more effective at improving the quality for both leachates, reaching COD, TOC and abs 254 nm reductions of 82%, 85% and 96.3%, respectively, for the Seropedica landfill leachate. In the case of the Gramacho landfill leachate, the corresponding reductions were 78.2, 80.7% and 91.1%, respectively. The biodegradability results for the untreated leachates from the Seropedica and Gramacho sites were 65% and 30% respectively. The biodegradability of both leachates was improved by the Fenton processes, especially the solar photo-Fenton process, which increased the leachate biodegradability to 89% (Seropedica) and 69% (Gramacho). For both leachates, a greater reduction in the acute toxicity was achieved with the solar photo-Fenton compared to the dark-Fenton process. The Seropedica landfill leachate showed high toxicity (EC50 = 33%, 15 min), after the dark Fenton and solar photo Fenton processes, with EC50 values of 81 and 91%, respectively. In the case of Gramacho landfill leachate toxicity, the EC50 value of the raw leachate was 13%, whereas after the dark Fenton and solar photo Fenton processes the corresponding values were 54% and 59%, respectively. These results indicate that the Fenton process (especially solar photo-Fenton), was efficient in terms of increasing the biodegradability and reducing the toxicity of the leachate. This is important in relation to protecting the microbiological community in the activated sludge process. Copyright © 2018 Elsevier Ltd. All rights reserved.

BIOPLUME MODEL FOR CONTAMINANT TRANSPORT AFFECTED BY OXYGEN LIMITED BIODEGRADATION

EPA Science Inventory

Many of the organic pollutants entering ground water are potentially biodegradable in the subsurface. This potential has been demonstrated in aquifers contaminated by wood-creosoting process wastes. The persistence of many of these organic compounds in the subsurface indicated ...

Effect of rhizosphere on soil microbial community and in-situ pyrene biodegradation

USGS Publications Warehouse

Su, Y.; Yang, X.; Chiou, C.T.

2008-01-01

To access the influence of a vegetation on soil microorganisms toward organic pollutant biogegration, this study examined the rhizospheric effects of four plant species (sudan grass, white clover, alfalfa, and fescue) on the soil microbial community and in-situ pyrene (PYR) biodegradation. The results indicated that the spiked PYR levels in soils decreased substantially compared to the control soil without planting. With equal planted densities, the efficiencies of PYR degradation in rhizosphere with sudan grass, white clover, alfalfa and fescue were 34.0%, 28.4%, 27.7%, and 9.9%, respectively. However, on the basis of equal root biomass the efficiencies were in order of white clover >> alfalfa > sudan > fescue. The increased PYR biodegradation was attributed to the enhanced bacterial population and activity induced by plant roots in the rhizosphere. Soil microbial species and biomasses were elucidated in terms of microbial phospholipid ester-linked fatty acid (PLFA) biomarkers. The principal component analysis (PCA) revealed significant changes in PLFA pattern in planted and non-planted soils spiked with PYR. Total PLFAs in planted soils were all higher than those in non-planted soils. PLFA assemblages indicated that bacteria were the primary PYR degrading microorganisms, and that Gram-positive bacteria exhibited higher tolerance to PYR than Gram-negative bacteria did. ?? 2008 Higher Education Press and Springer-Verlag GmbH.

Application of bioinformatics tools and databases in microbial dehalogenation research (a review).

PubMed

Satpathy, R; Konkimalla, V B; Ratha, J

2015-01-01

Microbial dehalogenation is a biochemical process in which the halogenated substances are catalyzed enzymatically in to their non-halogenated form. The microorganisms have a wide range of organohalogen degradation ability both explicit and non-specific in nature. Most of these halogenated organic compounds being pollutants need to be remediated; therefore, the current approaches are to explore the potential of microbes at a molecular level for effective biodegradation of these substances. Several microorganisms with dehalogenation activity have been identified and characterized. In this aspect, the bioinformatics plays a key role to gain deeper knowledge in this field of dehalogenation. To facilitate the data mining, many tools have been developed to annotate these data from databases. Therefore, with the discovery of a microorganism one can predict a gene/protein, sequence analysis, can perform structural modelling, metabolic pathway analysis, biodegradation study and so on. This review highlights various methods of bioinformatics approach that describes the application of various databases and specific tools in the microbial dehalogenation fields with special focus on dehalogenase enzymes. Attempts have also been made to decipher some recent applications of in silico modeling methods that comprise of gene finding, protein modelling, Quantitative Structure Biodegradibility Relationship (QSBR) study and reconstruction of metabolic pathways employed in dehalogenation research area.

In vivo cleansing efficacy of biodegradable exfoliating beads assessed by skin bioengineering techniques.

PubMed

Kitsongsermthon, J; Duangweang, K; Kreepoke, J; Tansirikongkol, A

2017-11-01

The plastic microbeads, used in many cleansers, will be banned in cosmetic and personal care products within 2017 since they are non-degradable and can disturb the living organisms in water reservoirs. Various choices of biodegradable beads are commercially available, but their efficacy has not been proven yet. This study aimed to compare the cleansing efficacy in dirt and sebum removal aspects of three types of exfoliating beads. The gel scrubs with polyethylene (PE) beads, mannan beads or wax beads, were formulated and evaluated for their stability. The in vivo evaluation was done in 38 healthy volunteers and the skin irritation, efficacy for dirt and sebum removal were measured by Mexameter ® , Colorimeter ® , and Sebumeter ® , respectively. The selected gel scrubs did not cause an irritation in any volunteers. The differences in dirt residues between before and after scrubbing were not statistically significant among three gel scrubs and the similar result was also reported in the sebum removal study. All gel scrubs demonstrated the comparable cleansing efficacy in term of dirt and sebum removal. Thus, mannan beads and wax beads may be replaced non-biodegradable PE beads to achieve the similar cleansing effect. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Methane production and hydrolysis kinetics in the anaerobic degradation of wastewater screenings.

PubMed

Cadavid-Rodríguez, L S; Horan, N

2013-01-01

Anaerobic biodegradability and hydrolysis rates of wastewater screenings were determined using the biochemical methane potential test at 37 °C. The extent and rate of screenings conversion to methane of this complex and particulate substrate were investigated and since two stages of hydrolysis were identified, corresponding to the different types of materials in screenings, a linear and non-linear model was used. No accumulation of intermediary products was observed and so it was possible to use the methane production rate and a linear model to estimate the hydrolysis rate in the first phase of hydrolysis. The measured values of 0.061-0.127 d(-1) are in the range reported for other comparable organic wastes. It was also observed that the inoculum-to-substrate ratio has a large impact on methane production rate of screenings. The difference in biodegradation rates from the materials in screenings and the overall hydrolysis could be represented by the modified Gompertz non-linear model which was able to describe the methane production rate of screenings with a high confidence. Screenings were found to have 52% biodegradability on average and this shows the potential for volatile solids destruction. A two-stage process with an improved hydrolysis rate is proposed to ensure that the full potential of the material is exploited.

Biodegradation of high concentrations of benzene vapors in a two phase partition stirred tank bioreactor.

PubMed

Karimi, Ali; Golbabaei, Farideh; Neghab, Masoud; Pourmand, Mohammad Reza; Nikpey, Ahmad; Mohammad, Kazem; Mehrnia, Momammad Reza

2013-01-15

The present study examined the biodegradation rate of benzene vapors in a two phase stirred tank bioreactor by a bacterial consortium obtained from wastewater of an oil industry refinery house. Initially, the ability of the microbial consortium for degrading benzene was evaluated before running the bioreactor. The gaseous samples from inlet and outlet of bioreactor were directly injected into a gas chromatograph to determine benzene concentrations. Carbone oxide concentration at the inlet and outlet of bioreactor were also measured with a CO2 meter to determine the mineralization rate of benzene. Influence of the second non-aqueous phase (silicon oil) has been emphasized, so at the first stage the removal efficiency (RE) and elimination capacity (EC) of benzene vapors were evaluated without any organic phase and in the second stage, 10% of silicon oil was added to bioreactor media as an organic phase. Addition of silicon oil increased the biodegradation performance up to an inlet loading of 5580 mg/m3, a condition at which, the elimination capacity and removal efficiency were 181 g/m3/h and 95% respectively. The elimination rate of benzene increased by 38% in the presence of 10% of silicone oil. The finding of this study demonstrated that two phase partition bioreactors (TPPBs) are potentially effective tools for the treatment of gas streams contaminated with high concentrations of poorly water soluble organic contaminant, such as benzene.

BIODEGRADATION PROBABILITY PROGRAM (BIODEG)

EPA Science Inventory

The Biodegradation Probability Program (BIODEG) calculates the probability that a chemical under aerobic conditions with mixed cultures of microorganisms will biodegrade rapidly or slowly. It uses fragment constants developed using multiple linear and non-linear regressions and d...

Microbial activity and soil organic matter decay in roadside soils polluted with petroleum hydrocarbons

NASA Astrophysics Data System (ADS)

Mykhailova, Larysa; Fischer, Thomas; Iurchenko, Valentina

2015-04-01

It has been demonstrated previously that hydrocarbon addition to soil provokes soil organic matter priming (Zyakun et al., 2011). It has further been shown that petroleum hydrocarbons deposit to roadside soils bound to fine mineral particles and together with vehicle spray (Mykhailova et al., 2014), and that hydrocarbon concentrations decrease to safe levels within the first 15 m from the road, reaching background concentrations at 60-100 m distance (Mykhailova et al., 2013). It was the aim of this study to (I) identify the bioavailability of different petroleum hydrocarbon fractions to degradation and to (II) identify the native (i.e. pedogenic) C fraction affected by hydrocarbon-mediated soil organic matter priming during decay. To address this aim, we collected soil samples at distances from 1 to 100 m (sampling depth 15 cm) near the Traktorostroiteley avenue and the Pushkinskaya street in Kharkov, as well as near the country road M18 near Kharkov, Ukraine. The roads have been under exploitation for several decades, so microbial adaptation to enhanced hydrocarbon levels and full expression of effects could be assumed. The following C fractions were quantified using 13C-CP/MAS-NMR: Carbohydrates, Proteins, Lignin, Aliphates, Carbonyl/Carboxyl as well as black carbon according to Nelson and Baldock (2005). Petroleum hydrocarbons were determind after hexane extraction using GC-MS and divided into a light fraction (chain-length C27, Mykhailova et al., 2013). Potential soil respiration was determined every 48 h by trapping of CO2 evolving from 20 g soil in NaOH at 20 ° C and at 60% of the maximum water holding capacity and titration after a total incubation period of 4 weeks in the lab. It was found that soil respiration positively correlated with the ratio of the light fraction to the sum of medium and heavy fractions of petroleum hydrocarbons, which indicates higher biodegradation primarily of the light petroleum hydrocarbon fraction. Further, soil respiration was positively correlated with the carbohydrate fraction and negatively correlated with the aliphatic fraction of the soil C, while carbohydrate-C and alkyl-C increased and decreased with distance from the road, respectively. It is proposed that petroleum hydrocarbons supress soil biological activity at concentrations above 1500 mg kg-1, and that soil organic matter priming primarily affects the carbohydrate fraction of soil organic matter. It can be concluded that the abundance of solid carbohydrates (O-alkyl C) is of paramount importance for the hydrocarbon mineralization under natural conditions, compared to more recalcitrant SOM fractions (mainly aromatic and alkyl C). References Mykhailova, L., Fischer, T., Iurchenko, V. (2013) Distribution and fractional composition of petroleum hydrocarbons in roadside soils. Applied and Environmental Soil Science, vol. 2013, Article ID 938703, 6 pages, DOI 10.1155/2013/938703 Mykhailova, L., Fischer, T., Iurchenko, V. (2014) Deposition of petroleum hydrocarbons with sediment trapped in snow in roadside areas. Journal of Environmental Engineering and Landscape Management 22(3):237-244, DOI 10.3846/16486897.2014.889698 Nelson P.N. and Baldock J.A. (2005) Estimating the molecular composition of a diverse range of natural organic materials from solid-state 13C NMR and elemental analyses, 2005, Biogeochemistry (2005) 72: 1-34, DOI 10.1007/s10533-004-0076-3 Zyakun, A., Nii-Annang, S., Franke, G., Fischer, T., Buegger, F., Dilly, O. (2011) Microbial Actvity and 13C/12C Ratio as Evidence of N-Hexadecane and N-Hexadecanoic Acid Biodegradation in Agricultural and Forest Soils. Geomicrobiology Journal 28:632-647, DOI 10.1080/01490451.2010.489922

External validation of structure-biodegradation relationship (SBR) models for predicting the biodegradability of xenobiotics.

PubMed

Devillers, J; Pandard, P; Richard, B

2013-01-01

Biodegradation is an important mechanism for eliminating xenobiotics by biotransforming them into simple organic and inorganic products. Faced with the ever growing number of chemicals available on the market, structure-biodegradation relationship (SBR) and quantitative structure-biodegradation relationship (QSBR) models are increasingly used as surrogates of the biodegradation tests. Such models have great potential for a quick and cheap estimation of the biodegradation potential of chemicals. The Estimation Programs Interface (EPI) Suite™ includes different models for predicting the potential aerobic biodegradability of organic substances. They are based on different endpoints, methodologies and/or statistical approaches. Among them, Biowin 5 and 6 appeared the most robust, being derived from the largest biodegradation database with results obtained only from the Ministry of International Trade and Industry (MITI) test. The aim of this study was to assess the predictive performances of these two models from a set of 356 chemicals extracted from notification dossiers including compatible biodegradation data. Another set of molecules with no more than four carbon atoms and substituted by various heteroatoms and/or functional groups was also embodied in the validation exercise. Comparisons were made with the predictions obtained with START (Structural Alerts for Reactivity in Toxtree). Biowin 5 and Biowin 6 gave satisfactorily prediction results except for the prediction of readily degradable chemicals. A consensus model built with Biowin 1 allowed the diminution of this tendency.

Influence of a compost layer on the attenuation of 28 selected organic micropollutants under realistic soil aquifer treatment conditions: insights from a large scale column experiment.

PubMed

Schaffer, Mario; Kröger, Kerrin Franziska; Nödler, Karsten; Ayora, Carlos; Carrera, Jesús; Hernández, Marta; Licha, Tobias

2015-05-01

Soil aquifer treatment is widely applied to improve the quality of treated wastewater in its reuse as alternative source of water. To gain a deeper understanding of the fate of thereby introduced organic micropollutants, the attenuation of 28 compounds was investigated in column experiments using two large scale column systems in duplicate. The influence of increasing proportions of solid organic matter (0.04% vs. 0.17%) and decreasing redox potentials (denitrification vs. iron reduction) was studied by introducing a layer of compost. Secondary effluent from a wastewater treatment plant was used as water matrix for simulating soil aquifer treatment. For neutral and anionic compounds, sorption generally increases with the compound hydrophobicity and the solid organic matter in the column system. Organic cations showed the highest attenuation. Among them, breakthroughs were only registered for the cationic beta-blockers atenolol and metoprolol. An enhanced degradation in the columns with organic infiltration layer was observed for the majority of the compounds, suggesting an improved degradation for higher levels of biodegradable dissolved organic carbon. Solely the degradation of sulfamethoxazole could clearly be attributed to redox effects (when reaching iron reducing conditions). The study provides valuable insights into the attenuation potential for a wide spectrum of organic micropollutants under realistic soil aquifer treatment conditions. Furthermore, the introduction of the compost layer generally showed positive effects on the removal of compounds preferentially degraded under reducing conditions and also increases the residence times in the soil aquifer treatment system via sorption. Copyright © 2015 Elsevier Ltd. All rights reserved.

BIOPLUME III: NATURAL ATTENTUATION DECISION SUPPORT SYSTEM USER'S MANUAL - VERSION 1.0

EPA Science Inventory

The BIOPLUME III program is a two-dimensional, finite difference model for simulating the natural attenuation of organic contaminants in ground water due to the processes of advection, dispersion, sorption, and biodegradation. The model simulates the biodegradation of organic...

Enhanced Amendment Delivery to Low Permeability Zones for Chlorinated Solvent Source Area Bioremediation

DTIC Science & Technology

2014-10-01

enhanced amendments delivery process, a non-toxic biodegradable polymer, such as xanthan gum, is added to the injection solution to form a non- Newtonian...Once injection stops, the injected fluid viscosity increases and creates a more stable zone for biodegradation reactions because the amendment-laden...electron acceptors and biodegradation of the shear-thinning agent. • Determine the cost factors for applying the STF enhanced delivery technology

Terminal Proterozoic reorganization of biogeochemical cycles

NASA Technical Reports Server (NTRS)

Logan, G. A.; Hayes, J. M.; Hieshima, G. B.; Summons, R. E.

1995-01-01

The Proterozoic aeon (2,500-540 million years ago) saw episodic increases in atmospheric oxygen content, the evolution of multicellular life and, at its close, an enormous radiation of animal diversity. These profound biological and environmental changes must have been linked, but the underlying mechanisms have been obscure. Here we show that hydrocarbons extracted from Proterozoic sediments in several locations worldwide are derived mainly from bacteria or other heterotrophs rather than from photosynthetic organisms. Biodegradation of algal products in sedimenting matter was therefore unusually complete, indicating that organic material was extensively reworked as it sank slowly through the water column. We propose that a significant proportion of this reworking will have been mediated by sulphate-reducing bacteria, forming sulphide. The production of sulphide and consumption of oxygen near the ocean surface will have inhibited transport of O2 to the deep ocean. We find that preservation of algal-lipid skeletons improves at the beginning of the Cambrian, reflecting the increase in transport by rapidly sinking faecal pellets. We suggest that this rapid removal of organic matter will have increased oxygenation of surface waters, leading to a descent of the O2-sulphide interface to the sea floor and to marked changes in the marine environment, ultimately contributing to the Cambrian radiation.

The role of organic matter and clay content in sediments for bioavailability of pyrene.

PubMed

Spasojević, Jelena; Maletić, Snežana; Rončević, Srđan; Grgić, Marko; Krčmar, Dejan; Varga, Nataša; Dalmacija, Božo

2018-01-01

Evaluation of the bioavailable fractions of organic contaminants such as polycyclic aromatic hydrocarbons (PAHs) is extremely important for assessing their risk to the environment. This available fraction, which can be solubilised and/or easily extracted, is believed to be the most accessible for bioaccumulation, biosorption and/or transformation. Sediment organic matter (OM) and clay play an important role in the biodegradation and bioavailability of PAHs. The strong association of PAHs with OM and clay in sediments has a great influence not only on their distribution but also on their long-term environmental impact. This paper investigates correlations between bioavailability and the clay and OM contents in sediments. The results show that OM is a better sorbent for pyrene (chosen as a model PAH) and that increasing the OM content reduces the bioavailable fraction. A mathematical model was used to predict the kinetic desorption, and these results showed that the sediment with the lowest content of OM had an F fast value of 24%, whereas sediment with 20% OM gave a value of 9%. In the experiments with sediments with different clay contents, no clear dependence between clay and rate constants of the fast desorbing fractions was observed, which can be explained by the numerous possible interactions at the molecular level.

Aerobic SMBR/reverse osmosis system enhanced by Fenton oxidation for advanced treatment of old municipal landfill leachate.

PubMed

Zhang, Guoliang; Qin, Lei; Meng, Qin; Fan, Zheng; Wu, Dexin

2013-08-01

A novel combined process of Fenton oxidation, submerged membrane bioreactor (SMBR) and reverse osmosis (RO) was applied as an appropriate option for old municipal landfill leachate treatment. Fenton process was designed to intensively solve the problem of non-biodegradable organic pollutant removal and low biodegradability of leachate, although the removal of ammonia-nitrogen was similar to 10%. After SMBR treatment, it not only presented a higher removal efficiency of organics, but also exhibited high ammonia-nitrogen removal of 80% on average. The variation of extracellular polymeric substance (EPS) content, zeta potential, and particle size of flocs after Fenton effluent continually fed in SMBR was found to be benefit for alleviating membrane fouling. Finally, three kinds of RO membranes (RE, CPA, and BW) were applied to treat SMBR effluents and successfully met wastewater re-utilization requirement. Compared with simple RO process, the troublesome membrane fouling can be effectively reduced in the combined process. Copyright © 2013 Elsevier Ltd. All rights reserved.

The University of Minnesota Biocatalysis/Biodegradation Database: specialized metabolism for functional genomics.

PubMed Central

Ellis, L B; Hershberger, C D; Wackett, L P

1999-01-01

The University of Minnesota Biocatalysis/Biodegradation Database (UM-BBD, http://www.labmed.umn.edu/umbbd/i nde x.html) first became available on the web in 1995 to provide information on microbial biocatalytic reactions of, and biodegradation pathways for, organic chemical compounds, especially those produced by man. Its goal is to become a representative database of biodegradation, spanning the diversity of known microbial metabolic routes, organic functional groups, and environmental conditions under which biodegradation occurs. The database can be used to enhance understanding of basic biochemistry, biocatalysis leading to speciality chemical manufacture, and biodegradation of environmental pollutants. It is also a resource for functional genomics, since it contains information on enzymes and genes involved in specialized metabolism not found in intermediary metabolism databases, and thus can assist in assigning functions to genes homologous to such less common genes. With information on >400 reactions and compounds, it is poised to become a resource for prediction of microbial biodegradation pathways for compounds it does not contain, a process complementary to predicting the functions of new classes of microbial genes. PMID:9847233

Removal of refractory organics in nanofiltration concentrates of municipal solid waste leachate treatment plants by combined Fenton oxidative-coagulation with photo--Fenton processes.

PubMed

Li, Jiuyi; Zhao, Lei; Qin, Lele; Tian, Xiujun; Wang, Aimin; Zhou, Yanmei; Meng, Liao; Chen, Yong

2016-03-01

Removal of the refractory organic matters in leachate brines generated from nanofiltration unit in two full-scale municipal solid waste landfill leachate treatment plants was investigated by Fenton oxidative-coagulation and ultraviolet photo - Fenton processes in this study. Fenton oxidative-coagulation was performed under the condition of an initial pH of 5.0 and low H2O2/Fe(2+) ratios. After precipitate separation, the remaining organic constituents were further oxidized by photo - Fenton process. For both leachate brines with varying pollution strength, more than 90% COD and TOC reductions were achieved at H2O2/Fe(2+) dosages of 35 mM/8 mM and 90 mM/10 mM, respectively. The effluent COD ranged 120-160 mg/L under the optimal operating conditions, and the biodegradability was increased significantly. Fenton oxidative-coagulation was demonstrated to contribute nearly 70% overall removal of organic matters. In the combined processes, the efficiency of hydrogen peroxide varied from 216 to 228%, which may significantly reduce the operating cost of conventional Fenton method. Six phthalic acid esters and thirteen polycyclic aromatic hydrocarbons were found in leachate brines, and, on the average, around 80% phthalic acid esters and 90% polycyclic aromatic hydrocarbons were removed by the combined treatments. Copyright © 2015 Elsevier Ltd. All rights reserved.

A REVIEW OF STRUCTURE-BASED BIODEGRADATION ESTIMATION METHODS. (R825370C077)

EPA Science Inventory

Biodegradation, being the principal abatement process in the environment, is the most important parameter influencing the toxicity, persistence, and ultimate fate in aquatic and terrestrial ecosystems. Biodegradation of an organic chemical in natural systems may be classified ...

A REVIEW OF STRUCTURE-BASED BIODEGRADATION ESTIMATION METHODS. (R825370C064)

EPA Science Inventory

Biodegradation, being the principal abatement process in the environment, is the most important parameter influencing the toxicity, persistence, and ultimate fate in aquatic and terrestrial ecosystems. Biodegradation of an organic chemical in natural systems may be classified ...

Biodegradation: Updating the concepts of control for microbial cleanup in contaminated aquifers.

PubMed

Meckenstock, Rainer U; Elsner, Martin; Griebler, Christian; Lueders, Tillmann; Stumpp, Christine; Aamand, Jens; Agathos, Spiros N; Albrechtsen, Hans-Jørgen; Bastiaens, Leen; Bjerg, Poul L; Boon, Nico; Dejonghe, Winnie; Huang, Wei E; Schmidt, Susanne I; Smolders, Erik; Sørensen, Sebastian R; Springael, Dirk; van Breukelen, Boris M

2015-06-16

Biodegradation is one of the most favored and sustainable means of removing organic pollutants from contaminated aquifers but the major steering factors are still surprisingly poorly understood. Growing evidence questions some of the established concepts for control of biodegradation. Here, we critically discuss classical concepts such as the thermodynamic redox zonation, or the use of steady state transport scenarios for assessing biodegradation rates. Furthermore, we discuss if the absence of specific degrader populations can explain poor biodegradation. We propose updated perspectives on the controls of biodegradation in contaminant plumes. These include the plume fringe concept, transport limitations, and transient conditions as currently underestimated processes affecting biodegradation.

Spatio-seasonal variability in dissolved organic matter optical properties and its bioavailability in a subalpine lake

NASA Astrophysics Data System (ADS)

Stadler, Masumi; Ejarque, Elisabet; Kainz, Martin J.

2017-04-01

Allochthonous and autochothonous dissolved organic matter (DOM) in lakes mainly originate from terrestrial and aquatic primary production, respectively. Due to their differing biochemical composition the degradability of DOM by microorganisms is expected to vary. The carbon use efficiency of bacteria and DOM biodegradability determine whether the consumed DOM is incorporated into microbial biomass or respired to CO2 and ultimately emitted into the atmosphere. Thus, understanding the interaction of biodegradable DOM and its consumers is crucial to increase our knowledge on the role of lakes in the global carbon cycling. However, interactions of specific aquatic DOM signatures and the microbial population still remain widely debated. The aim of this study was to explore how DOM biodegradability changes along a stream-lake continuum at different seasons of the year. We monitored DOM quantity and its optical properties, inorganic nutrients, CO2 and bacterial growth over 20 days in dark bioassays with water from the inflow, outflow and at three layers of an oligotrophic subalpine lake. Preliminary results reveal highest microbial abundance in the metalimnion in winter and summer (0.7 106 and 2.5 106 cells mL-1, respectively) and the inflow in spring and autumn (1 106 and 1.4 106 cells mL-1, respectively) after 20 days. Surprisingly, with the exception of winter samples final inflow bacterial abundance results high, despite its lowest initial natural cell concentration, providing evidence for effective utilisation of terrestrial DOM, even with its high humic signature as indicated by the humification index (HIX). Nonetheless, after a microbial biomass peak with the inflow yielding mostly highest after three days, at the final experimental stage microbial biomass does only marginally differ between all sites with the exception of autumn samples where outflow and metalimnion turn out most productive. Even though the DOM of all lake sites and the lake outflow were characterised by lower molecular weight (indicated by the slope ratio (SR)) and a higher autochthonous signature (BIX) in all seasons, rapid growth of inflow bacteria highlight the potential of terrestrially-derived DOM to support bacterial growth, and challenge previous ideas that autchthonously-produced DOM would be more labile than DOM of terrestrial origin.

Precursors of Halobenzoquinones and Their Removal During Drinking Water Treatment Processes.

PubMed

Wang, Wei; Qian, Yichao; Jmaiff, Lindsay K; Krasner, Stuart W; Hrudey, Steve E; Li, Xing-Fang

2015-08-18

Halobenzoquinones (HBQs) widely occur in drinking water treatment plant (DWTP) effluents; however, HBQ precursors and their removal by treatments remain unclear. Thus, we have investigated HBQ precursors in plant influents and their removal by each treatment before chlorination in nine DWTPs. The levels of HBQ precursors were determined using formation potential (FP) tests for 2,6-dichloro-1,4-benzoquinone (DCBQ), 2,3,6-trichloro-1,4-benzoquinone (TCBQ), 2,6-dichloro-3-methyl-1,4-benzoquinone (DCMBQ), and 2,6-dibromo-1,4-benzoquinone (DBBQ). HBQ precursors were present in all plant influents. DCBQ precursors were the most abundant (DCBQ FP up to 205 ng/L). Coagulation removed dissolved organic carbon (DOC) (up to 56%) and HBQ precursors (up to 39% for DCBQ). The level of removal of DOC was significantly greater than the level of removal of HBQ FP, suggesting that organic matter removed by coagulation had a high proportion of non-HBQ-precursor material. Granular activated carbon (GAC) decreased the level of HBQ FPs by 10-20%, where DOC removal was only 0.2-4.7%, suggesting that the GAC was not in the adsorption mode and biodegradation of HBQ precursors may have been occurring. Ozonation destroyed/transformed HBQ FPs by 10-30%, whereas anthracite/sand filtration and UV irradiation appeared to have no impact. The results demonstrated that the combined treatments did not substantially reduce HBQ precursor levels in water.

Prediction of temperature and thermal inertia effect in the maturation stage and stockpiling of a large composting mass

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

Barrena, R.; Canovas, C.; Sanchez, A.

2006-07-01

A macroscopic non-steady state energy balance was developed and solved for a composting pile of source-selected organic fraction of municipal solid waste during the maturation stage (13,500 kg of compost). Simulated temperature profiles correlated well with temperature experimental data (ranging from 50 to 70 deg. C) obtained during the maturation process for more than 50 days at full scale. Thermal inertia effect usually found in composting plants and associated to the stockpiling of large composting masses could be predicted by means of this simplified energy balance, which takes into account terms of convective, conductive and radiation heat dissipation. Heat lossesmore » in a large composting mass are not significant due to the similar temperatures found at the surroundings and at the surface of the pile (ranging from 15 to 40 deg. C). In contrast, thermophilic temperature in the core of the pile was maintained during the whole maturation process. Heat generation was estimated with the static respiration index, a parameter that is typically used to monitor the biological activity and stability of composting processes. In this study, the static respiration index is presented as a parameter to estimate the metabolic heat that can be generated according to the biodegradable organic matter content of a compost sample, which can be useful in predicting the temperature of the composting process.« less

Building organic matter of long-term sugarcane soils in a temperate environment

USDA-ARS?s Scientific Manuscript database

Mineral soils with a history of sugarcane monoculture cropping contain less soil organic matter (-35%), and plant macro- and micronutrients, including N (-20%), K (-26%), S (-7%), Ca (-8%), B (-33%), Zn (-88%), Mn (-29%), and Cu (-26%), than adjacent non-cultivated soils. Harvesting sugarcane ‘green...

Non-biodegradable landfill leachate treatment by combined process of agitation, coagulation, SBR and filtration

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

Abood, Alkhafaji R.; Thi Qar University, Nasiriyah; Bao, Jianguo, E-mail: bjianguo888@126.com

2014-02-15

Highlights: • A novel method of stripping (agitation) was investigated for NH{sub 3}-N removal. • PFS coagulation followed agitation process enhanced the leachate biodegradation. • Nitrification–denitrification achieved by changing operation process in SBR treatment. • A dual filter of carbon-sand is suitable as a polishing treatment of leachate. • Combined treatment success for the complete treatment of non-biodegradable leachate. - Abstract: This study describes the complete treatment of non-biodegradable landfill leachate by combined treatment processes. The processes consist of agitation as a novel stripping method used to overcome the ammonia toxicity regarding aerobic microorganisms. The NH{sub 3}-N removal ratio wasmore » 93.9% obtained at pH 11.5 and a gradient velocity (G) 150 s{sup −1} within a five-hour agitation time. By poly ferric sulphate (PFS) coagulation followed the agitation process; chemical oxygen demand (COD) and biological oxygen demand (BOD{sub 5}) were removed at 70.6% and 49.4%, respectively at an optimum dose of 1200 mg L{sup −1} at pH 5.0. The biodegradable ratio BOD{sub 5}/COD was improved from 0.18 to 0.31 during pretreatment step by agitation and PFS coagulation. Thereafter, the effluent was diluted with sewage at a different ratio before it was subjected to sequencing batch reactor (SBR) treatment. Up to 93.3% BOD{sub 5}, 95.5% COD and 98.1% NH{sub 3}-N removal were achieved by SBR operated under anoxic–aerobic–anoxic conditions. The filtration process was carried out using sand and carbon as a dual filter media as polishing process. The final effluent concentration of COD, BOD{sub 5}, suspended solid (SS), NH{sub 3}-N and total organic carbon (TOC) were 72.4 mg L{sup −1}, 22.8 mg L{sup −1}, 24.2 mg L{sup −1}, 18.4 mg L{sup −1} and 50.8 mg L{sup −1} respectively, which met the discharge standard. The results indicated that a combined process of agitation-coagulation-SBR and filtration effectively eliminated pollutant loading from landfill leachate.« less

Determination of optimal conditions for 5-methyl-benzotriazole biodegradation with activated sludge communities by dilution of the inoculum.

PubMed

Yuan, Heyang; Herzog, Bastian; Helmreich, Brigitte; Lemmer, Hilde; Müller, Elisabeth

2014-07-15

The aerobic biodegradation of 5-methyl-benzotriazole (5-TTri) was optimized using lab-scale setups and activated sludge communities (ASC) collected from three wastewater treatment plants (WWTP) MBR-MH, CAS-E and CAS-M being different in their treatment technologies. ASC inocula were diluted to rule out non-biodegrading species and incubated under two nutrient conditions: A) mineral salt media (MSM) and B) carbon and nitrogen supplied MSM giving MSM-CN. 5-TTri removal with the ASC ranged from 60% to 100% in only 10 days. 100 μL suspended biomass from the biodegrading setups was subsequently plated on solid media to eliminate possible activated sludge remnants. After growth occurred, mixed colonies were harvested and inoculated in fresh liquid MSM containing 20 mg L(-1) 5-TTri. These bacterial consortia showed good 5-TTri removal in MSM-CN rather than in MSM, indicating nutrient supply being required for efficient biodegradation. In addition, experiments with high 5-TTri concentrations ranging from 20 to 1,000 mg L(-1) were conducted in both, MSM and MSM-CN and the maximal 5-TTri removal capacity of the ASC evaluated. 50 mg L(-1) 5-TTri was still removed in both media whereas 100 mg L(-1) was solely removed in MSM-CN. 5-TTri biodegradation patterns also indicated that 5-TTri might be co-metabolized by microbial consortia. Furthermore, experiments with gradient-solid-media-plates showed 5-TTri to be inhibitory for the ASC in concentrations above 50 mg L(-1) and revealed the optimal conditions regarding carbon and nitrogen concentration and pH value for effective 5-TTri biodegradation by ASC. Nitrogen proved a crucial factor for enhancing organisms' biodegradation capacity with an optimal pH around 7 while carbon showed no such effect. Copyright © 2013 Elsevier B.V. All rights reserved.

Biodegradable nanoparticles for gene therapy technology

NASA Astrophysics Data System (ADS)

Hosseinkhani, Hossein; He, Wen-Jie; Chiang, Chiao-Hsi; Hong, Po-Da; Yu, Dah-Shyong; Domb, Abraham J.; Ou, Keng-Liang

2013-07-01

Rapid propagations in materials technology together with biology have initiated great hopes in the possibility of treating many diseases by gene therapy technology. Viral and non-viral gene carriers are currently applied for gene delivery. Non-viral technology is safe and effective for the delivery of genetic materials to cells and tissues. Non-viral systems are based on plasmid expression containing a gene encoding a therapeutic protein and synthetic biodegradable nanoparticles as a safe carrier of gene. Biodegradable nanoparticles have shown great interest in drug and gene delivery systems as they are easy to be synthesized and have no side effect in cells and tissues. This review provides a critical view of applications of biodegradable nanoparticles on gene therapy technology to enhance the localization of in vitro and in vivo and improve the function of administered genes.

Magnesium Powder Injection Molding (MIM) of Orthopedic Implants for Biomedical Applications

NASA Astrophysics Data System (ADS)

Wolff, M.; Schaper, J. G.; Suckert, M. R.; Dahms, M.; Ebel, T.; Willumeit-Römer, R.; Klassen, T.

2016-04-01

Metal injection molding (MIM) has a high potential for the economic near-net-shape mass production of small-sized and complex-shaped parts. The motivation for launching Mg into the MIM processing chain for manufacturing biodegradable medical implants is related to its compatibility with human bone and its degradation in a non-toxic matter. It has been recognized that the load-bearing capacity of MIM Mg parts is superior to that of biodegradable polymeric components. However, the choice of appropriate polymeric binder components and alloying elements enabling defect-free injection molding and sintering is a major challenge for the use of MIM Mg parts. This study considered the full processing chain for MIM of Mg-Ca alloys to achieve ultimate tensile strength of up to 141 MPa with tensile yield strength of 73 MPa, elongation at fracture Af of 7% and a Young's modulus of 38 GPa. To achieve these mechanical properties, a thermal debinding study was performed to determine optimal furnace and atmosphere conditions, sintering temperature, heating rates, sintering time and pressure.

ANAEROBIC BIODEGRADABILITY OF NON-PETROLEUM OILS.

EPA Science Inventory

Research has demonstrated that vegetable oils are amenable to anaerobic biodegradation. This is in contrast to petroleum oils. Vegetable oils are already oxygenated because they are composed of fatty acids and glycerols, which contribute to the biodegradability. A strategy has be...

Composition, dynamics, and fate of leached dissolved organic matter in terrestrial ecosystems: Results from a decomposition experiment

USGS Publications Warehouse

Cleveland, C.C.; Neff, J.C.; Townsend, A.R.; Hood, E.

2004-01-01

Fluxes of dissolved organic matter (DOM) are an important vector for the movement of carbon (C) and nutrients both within and between ecosystems. However, although DOM fluxes from throughfall and through litterfall can be large, little is known about the fate of DOM leached from plant canopies, or from the litter layer into the soil horizon. In this study, our objectives were to determine the importance of plant-litter leachate as a vehicle for DOM movement, and to track DOM decomposition [including dissolve organic carbon (DOC) and dissolved organic nitrogen (DON) fractions], as well as DOM chemical and isotopic dynamics, during a long-term laboratory incubation experiment using fresh leaves and litter from several ecosystem types. The water-extractable fraction of organic C was high for all five plant species, as was the biodegradable fraction; in most cases, more than 70% of the initial DOM was decomposed in the first 10 days of the experiment. The chemical composition of the DOM changed as decomposition proceeded, with humic (hydrophobic) fractions becoming relatively more abundant than nonhumic (hydrophilic) fractions over time. However, in spite of proportional changes in humic and nonhumic fractions over time, our data suggest that both fractions are readily decomposed in the absence of physicochemical reactions with soil surfaces. Our data also showed no changes in the ??13C signature of DOM during decomposition, suggesting that isotopic fractionation during DOM uptake is not a significant process. These results suggest that soil microorganisms preferentially decompose more labile organic molecules in the DOM pool, which also tend to be isotopically heavier than more recalcitrant DOM fractions. We believe that the interaction between DOM decomposition dynamics and soil sorption processes contribute to the ??13C enrichment of soil organic matter commonly observed with depth in soil profiles.

Characterization of a joint recirculation of concentrated leachate and leachate to landfills with a microaerobic bioreactor for leachate treatment.

PubMed

He, Ruo; Wei, Xiao-Meng; Tian, Bao-Hu; Su, Yao; Lu, Yu-Lan

2015-12-01

With comparison of a traditional landfill, a joint recirculation of concentrated leachate and leachate to landfills with or without a microaerobic reactor for leachate treatment was investigated in this study. The results showed that the joint recirculation of concentrated leachate and leachate with a microaerobic reactor for leachate treatment could not only utilize the microaerobic reactor to buffer the fluctuation of quality and quantity of leachate during landfill stabilization, but also reduce the inhibitory effect of acidic pH and high concentrations of ammonium in recycled liquid on microorganisms and accelerate the degradation of landfilled waste. After 390 days of operation, the discharge of COD and total nitrogen (TN) from the landfill with leachate pretreatment by a microaerobic reactor was 7.4 and 0.9 g, respectively, which accounted for 0.7% and 2.6% of COD, 1.9% and 7.5% of the TN discharge from the landfills without recirculation and directly recirculated with leachate and concentrated leachate, respectively. The degradation of the organic matter and biodegradable matter (BDM) in the landfill reactors could fit well with the first-order kinetics. The highest degradation of the organic matter and BDM was observed in the joint recirculation system with a microaerobic reactor for leachate treatment with the degradation constant of the first-order kinetics of 0.001 and 0.002. Copyright © 2015 Elsevier Ltd. All rights reserved.

Impact of solids retention time on dissolved organic nitrogen and its biodegradability in treated wastewater

USDA-ARS?s Scientific Manuscript database

Dissolved organic nitrogen (DON) and its biodegradability in treated wastewater have recently gained attention because DON potentially causes oxygen depletion and/or eutrophication in receiving waters. Laboratory scale chemostat experiments were conducted at 9 different solids retention times (SRTs)...

Application of stable isotope tools for evaluating natural and stimulated biodegradation of organic pollutants in field studies.

PubMed

Fischer, Anko; Manefield, Mike; Bombach, Petra

2016-10-01

Stable isotope tools are increasingly applied for in-depth evaluation of biodegradation of organic pollutants at contaminated field sites. They can be divided into three methods i) determination of changes in natural abundance of stable isotopes using compound-specific stable isotope analysis (CSIA), ii) detection of incorporation of stable-isotope label from a stable-isotope labelled target compound into degradation and/or mineralisation products and iii) determination of stable-isotope label incorporation into biomarkers using stable isotope probing (SIP). Stable isotope tools have been applied as key monitoring tools for multiple-line-of-evidence-approaches (MLEA) for sensitive evaluation of pollutant biodegradation. This review highlights the application of CSIA, SIP and MLEA including stable isotope tools for assessing natural and stimulated biodegradation of organic pollutants in field studies dealing with soil and groundwater contaminations. Copyright © 2016 Elsevier Ltd. All rights reserved.

Physical Pretreatment Methods for Improving Microalgae Anaerobic Biodegradability.

PubMed

Córdova, Olivia; Passos, Fabiana; Chamy, Rolando

2018-05-01

Microalgae may be a potential feedstock for biogas production through anaerobic digestion. However, this process is limited by the hydrolytic stage, due to the complex and resistant microalgae cell wall components. This fact hinders biomass conversion into biogas, demanding the application of pretreatment techniques for inducing cell damage and/or lysis and organic matter solubilisation. In this study, sonication, thermal, ultrasound, homogeneizer, hydrothermal and steam explosion pretreatments were evaluated in different conditions for comparing their effects on anaerobic digestion performance in batch reactors. The results showed that the highest biomass solubilisation values were reached for steam explosion (65-73%) and ultrasound (33-57%). In fact, only applied energies higher than 220 W or temperatures higher than 80 °C induced cell wall lysis in C. sorokiniana. Nonetheless, the highest methane yields were not correlated to biogas production. Thermal hydrolysis and steam explosion showed lower methane yields in respect to non-pretreated biomass, suggesting the presence of toxic compounds that inhibited the biological process. Accordingly, these pretreatment techniques led to a negative energy balance. The best pretreatment method among the ones evaluated was thermal pretreatment, with four times more energy produced that demanded.

Modeling Effects of Lability on Microbial Uptake of DOM in River Reaches

NASA Astrophysics Data System (ADS)

Li, A.; Drummond, J. D.; Bowen, J. C.; Cory, R. M.; Kaplan, L.; Packman, A. I.

2017-12-01

Rivers are hotspots for biological degradation of dissolved organic matter (DOM), contributing to 1.8 petagrams of carbon emissions per year. DOM represents approximately 60% of the total mass of organic carbon transported within river networks, fueling stream ecosystem metabolism. Not all DOM is biodegradable, biodegradation rates vary based on lability, and lability decreases with reaction time. Fluorescent fractions of DOM (FDOM) are often used as proxies of DOM lability. Humic-like FDOM, previously considered recalcitrant and thought to contribute minimally to the biodegradable DOM pools, has recently been shown to contribute more than 50% to DOM uptake in bioreactor columns colonized by bacteria in stream water. Protein-like FDOM, a proxy for the biodegradable DOM pool, also contributes to the recalcitrant DOM pool in bioreactors. However, the contribution of different lability pools to DOM uptake at the reach scale remains elusive. Here we combine local-scale results from a bioreactor study and measures of stream geomorphology parameters to model reach-scale DOM uptake in White Clay Creek, a Pennsylvania piedmont stream with an intact, forested riparian zone and inputs from upland agriculture. Steady state modeling of a point-source, continuous injection of FDOM shows that humic-like FDOM contributes up to 80% of the total removal of FDOM at the reach scale, suggesting its importance to in-stream DOM uptake. Tryptophan-like FDOM, a protein-like FDOM, contributes to 80% of the remaining fraction of FDOM at the reach scale that incorporates longer timescales of transport and retention. This is consistent with recent local-scale findings that the lability of tryptophan-like FDOM decreases substantially with reaction time in bioreactors, such that it becomes much more recalcitrant as it travels downstream. Steady state modeling of a distributed source, continuous injection of FDOM shows that contributing sources distribute differently along the river reach for each FDOM component, due to their different uptake patterns. Thus, variations of DOM lability are important for estimating reach-scale microbial uptake and contributing sources of in-stream DOM.

Development of dopant-free conductive bioelastomers

PubMed Central

Xu, Cancan; Huang, Yihui; Yepez, Gerardo; Wei, Zi; Liu, Fuqiang; Bugarin, Alejandro; Tang, Liping; Hong, Yi

2016-01-01

Conductive biodegradable materials are of great interest for various biomedical applications, such as tissue repair and bioelectronics. They generally consist of multiple components, including biodegradable polymer/non-degradable conductive polymer/dopant, biodegradable conductive polymer/dopant or biodegradable polymer/non-degradable inorganic additives. The dopants or additives induce material instability that can be complex and possibly toxic. Material softness and elasticity are also highly expected for soft tissue repair and soft electronics. To address these concerns, we designed a unicomponent dopant-free conductive polyurethane elastomer (DCPU) by chemically linking biodegradable segments, conductive segments, and dopant molecules into one polymer chain. The DCPU films which had robust mechanical properties with high elasticity and conductivity can be degraded enzymatically and by hydrolysis. It exhibited great electrical stability in physiological environment with charge. Mouse 3T3 fibroblasts survived and proliferated on these films exhibiting good cytocompatibility. Polymer degradation products were non-toxic. DCPU could also be processed into a porous scaffold and in an in vivo subcutaneous implantation model, exhibited good tissue compatibility with extensive cell infiltration over 2 weeks. Such biodegradable DCPU with good flexibility and elasticity, processability, and electrical stability may find broad applications for tissue repair and soft/stretchable/wearable bioelectronics. PMID:27686216

Impact assessment of intermediate soil cover on landfill stabilization by characterizing landfilled municipal solid waste.

PubMed

Qi, Guangxia; Yue, Dongbei; Liu, Jianguo; Li, Rui; Shi, Xiaochong; He, Liang; Guo, Jingting; Miao, Haomei; Nie, Yongfeng

2013-10-15

Waste samples at different depths of a covered municipal solid waste (MSW) landfill in Beijing, China, were excavated and characterized to investigate the impact of intermediate soil cover on waste stabilization. A comparatively high amount of unstable organic matter with 83.3 g kg(-1) dry weight (dw) total organic carbon was detected in the 6-year-old MSW, where toxic inorganic elements containing As, Cd, Cr, Cu, Mn, Ni, Pb, and Zn of 10.1, 0.98, 85.49, 259.7, 530.4, 30.5, 84.0, and 981.7 mg kg(-1) dw, respectively, largely accumulated because of the barrier effect of intermediate soil cover. This accumulation resulted in decreased microbial activities. The intermediate soil cover also caused significant reduction in moisture in MSW under the soil layer, which was as low as 25.9%, and led to inefficient biodegradation of 8- and 10-year-old MSW. Therefore, intermediate soil cover with low permeability seems to act as a barrier that divides a landfill into two landfill cells with different degradation processes by restraining water flow and hazardous matter. Copyright © 2013 Elsevier Ltd. All rights reserved.

Optical properties of dissolved organic matter (DOM): Effects of biological and photolytic degradation

USGS Publications Warehouse

Hansen, Angela; Kraus, Tamara; Pellerin, Brian; Fleck, Jacob; Downing, Bryan D.; Bergamaschi, Brian

2016-01-01

Advances in spectroscopic techniques have led to an increase in the use of optical properties (absorbance and fluorescence) to assess dissolved organic matter (DOM) composition and infer sources and processing. However, little information is available to assess the impact of biological and photolytic processing on the optical properties of original DOM source materials. We measured changes in commonly used optical properties and indices in DOM leached from peat soil, plants, and algae following biological and photochemical degradation to determine whether they provide unique signatures that can be linked to original DOM source. Changes in individual optical parameters varied by source material and process, with biodegradation and photodegradation often causing values to shift in opposite directions. Although values for different source materials overlapped at the end of the 111-day lab experiment, multivariate statistical analyses showed that unique optical signatures could be linked to original DOM source material even after degradation, with 17 optical properties determined by discriminant analysis to be significant (p<0.05) in distinguishing between DOM source and environmental processing. These results demonstrate that inferring the source material from optical properties is possible when parameters are evaluated in combination even after extensive biological and photochemical alteration.

Efficient degradation of lube oil by a mixed bacterial consortium.

PubMed

Wang, Haifeng; Xu, Ran; Li, Fengting; Qiao, Junlian; Zhang, Bingru

2010-01-01

A laboratory study was performed to assess the biodegradation of lube oil in bio-reactor with 304# stainless steel as a biofilm carrier. Among 164 oil degrading bacterial cultures isolated from oil contaminated soil samples, Commaonas acidovorans Pxl, Bacillus sp. Px2, Pseudomonas sp. Px3 were selected to prepare a mixed consortium for the study based on the efficiency of lube oil utilization. The percentage of oil degraded by the mixed bacterial consortium decreased slightly from 99% to 97.2% as the concentration of lube oil was increased from 2000 to 10,000 mg/L. The degradation of TDOC (total dissolved organic carbon) showed a similar tendency compared with lube oil removal, which indicated that the intermediates in degradation process hardly accumulated. Selected mixed bacterial consortium showed their edge compared to activated sludge. Scanning electron microscopy (SEM) photos showed that biofilms on stainless steel were robust and with a dimensional framework constructed by EPS (extracellular polymeric substances), which could promote the biodegradation of hydrocarbons. The increase of biofilm followed first-order kinetics with rate of 0.216 microg glucose/(cm2-day) in logarithm phase. With analysis of Fourier transform infrared spectroscopy (FT-IR) and gas chromatography-mass spectrometry (GC-MS) combined with removal of lube oil and TDOC, mixed bacterial consortium could degrade benzene and its derivatives, aromatic ring organic matters with a percentage over 97%.

Enhancing MRI of liver metastases with a zwitterionized biodegradable dendritic contrast agent.

PubMed

Zhou, Xiaoxuan; Ye, Mingzhou; Han, Yuxin; Tang, Jianbin; Qian, Yue; Hu, Hongjie; Shen, Youqing

2017-07-25

Metastasis is the main reason for cancer-associated mortality, and accurate diagnostic imaging of metastases is critical for the clinical administration and tailoring personalized treatments for metastatic tumors. However, magnetic resonance imaging of metastases in the liver is impeded by its low sensitivity because the currently used contrast agents accumulate in hepatocytes and Kupffer cells instead of cancer cells. Herein, a 4 th generation zwitterionized biodegradable dendritic contrast agent (DCA) with a size of ca. 9 nm and a longitudinal relaxivity of 15.7 mM -1 s -1 in terms of Gd was synthesized and used to enhance the MRI of liver metastasis. The DCA could remarkably enhance the MRI of metastasized tumors in the liver, because it could simultaneously reduce the background signal in the liver by avoiding uptake by hepatocytes and Kupffer cells through the zwitterionization and increase the signal in tumors through the enhanced permeability and retention effect. Moreover, in contrast to non-biodegradable DCA, this DCA showed minimal long-term Gd 3+ retention in all organs and tissues because it could be degraded into small fragments. The significant capability of enhancing the MRI of metastases in the liver plus its excellent biodegradability made this DCA a promising CA for metastatic tumor imaging.

Comparison of biodegradation of low-weight hydroentangled raw cotton nonwoven fabric and that of commonly used disposable nonwoven fabrics in the aerobic Captina silt loam soil

USDA-ARS?s Scientific Manuscript database

The increasing use of disposable nonwovens made of petroleum-based materials generates a large amount of non-biodegradable, solid waste in the environment. As an effort to enhance the usage of biodegradable cotton in nonwovens, this study analyzed the biodegradability of mechanically pre-cleaned gr...

78 FR 27321 - Revision of Auxiliary Regulations

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-10

... organization; amend provisions regarding Auxiliary membership; and address other administrative matters. These... Suits in Admiralty Act, the Admiralty Extension Act, and other matters related to non- contractual civil... (series)). Medals and awards are a matter of agency management and agency personnel, and therefore exempt...

Evaluating the primary and ready biodegradability of dianilinodithiophosphoric acid.

PubMed

Lin, Weixiong; Sun, Shuiyu; Xu, Pingting; Dai, Yongkang; Ren, Jie

2016-04-01

Dianilinodithiophosphoric acid (DDA) is widely used as sulfide mineral flotation collector in China. It is necessary to investigate the biodegradability of DDA to provide the fundamental knowledge to assess the environmental fate in the risk assessment of DDA and to design and operate the DDA flotation wastewater biological treatment plant. In the present study, the primary and ready aerobic biodegradations of DDA were studied and the primary biodegradation kinetic model of DDA was developed. The results show that DDA displays a good primary biodegradability and its biodegradation ratio reaches 99.8 % in 7 days. In contrast, DDA is not easily ready biodegradable; hence, it is a partially biodegradable organic compound. The primary aerobic biodegradation kinetics can be described using the first-order reaction kinetics equation: C = 19.72191e(-0.01513t).

40 CFR 98.464 - Monitoring and QA/QC requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... stream by either using at least a 60-day anaerobic biodegradation test as specified in paragraph (b)(4)(i... specified in paragraph (b)(4)(ii) of this section. (i) Perform an anaerobic biodegradation test and... standards organization to conduct a minimum of a 60-day anaerobic biodegradation test. Consensus-based...

40 CFR 98.464 - Monitoring and QA/QC requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

...-day anaerobic biodegradation test as specified in paragraph (b)(4)(i) of this section or by estimating...) of this section. (i) Perform an anaerobic biodegradation test and determine the DOC value of a waste... minimum of a 60-day anaerobic biodegradation test. Consensus-based standards organizations include, but...

Biodegradability of immidazolium, pyridinium, piperidinium and pyrrolidinium based ionic liquid in different water source

NASA Astrophysics Data System (ADS)

Krishnan, S.; Quraishi, K. S.; Aminuddin, N. F.; Mazlan, F. A.; Leveque, J.-M.

2016-11-01

Ionic Liquid (IL), combination of an organic cation with an organic or inorganic cation, possess some remarkable physical chemical properties such as no virtual vapor pressure (allowing recyclability and reusability), wide liquid range, high thermal and chemical stability, ease to choose hydrophobic/hydrophilic character and wide electrochemical window. Owing to that, they have become increasingly popular as green solvents/additives/catalysts for organic synthetic chemistry, extraction, electrochemistry, catalysis, biomass conversion, biotechnologies and pharmaceutical applications. This is acknowledged by the exponential number of yearly published articles related to them. However, even if these are very widely studied in the international scientific community, they are not or very little used on an industrial scale, particularly because of the lack of data on their toxicity and biodegradability. Notably hydrophobic ILs seems to display higher toxicity towards microorganisms and lower biodegradability compared to their hydrophilic analogues since they are not readily disassociated in water. This present work aims to explore the biodegradability of 8 different insoluble ILs in different sources of water bearing varied amount of microorganisms to study the impact of the used water on the biodegradability assessment. The water sources used are Type III Water, Pond water and filtered Sewage Water. Based on the results obtained, it can be concluded that the type of water has a very minor influence on the biodegradability effect of insoluble ILs. However, there is still some degree of influence on the type of water with the biodegradability.

A framework for modeling non-steady-state concentrations of semivolatile organic compounds indoors ― II. Interactions with particulate matter

EPA Science Inventory

This paper describes a method for dynamic modeling of the interactions of semivolatile organic compounds (SVOCs) with airborne and settled particulate matter in the indoor environment. This method is fully compatible with the other components within the framework. Despite the unc...

Speciation and Toxic Emissions from On road Vehicles, and Particulate Matter Emissions from Light-Duty Gasoline Vehicles in MOVES201X

EPA Science Inventory

Updated methane, non-methane organic gas, and volatile organic compound calculations based on speciation data. Updated speciation and toxic emission rates for new model year 2010 and later heavy-duty diesel engines. Updated particulate matter emission rates for 2004 and later mod...

Nutrient and organic matter inputs to Hawaiian anchialine ponds: influences of n-fixing and non-n-fixing trees

Treesearch

Kehauwealani K. Nelson-Kaula; Rebecca Ostertag; R. Flint Hughes; Bruce D. Dudley

2016-01-01

Invasive nitrogen-fixing plants often increase energy and nutrient inputs to both terrestrial and aquatic ecosystems via litterfall, and these effects may be more pronounced in areas lacking native N2-fixers. We examined organic matter and nutrient inputs to and around anchialine ponds...

Application of Bayesian belief net in modelling the origin and effects of terrigenous dissolved organic matter in a boreal aquatic ecosystem

NASA Astrophysics Data System (ADS)

Rahikainen, Mika; Hoikkala, Laura; Soinne, Helena

2013-04-01

Bayesian belief nets (BBN) are capable of developing holistic understanding of the origin, transportation, and effects of dissolved organic matter (DOM) in ecosystems. The role of riverine DOM, transporting carbon and macronutrients N and P into lakes and coastal areas, has been largely neglected in research about processes influencing aquatic ecosystem functions although dissolved organic matter provides a significant nutrient source for primary producers in aquatic environments. This neglect has also contributed to the environmental policies which are focused in the control of inorganic N and P load. It is of great social and economic interest to gain improved knowledge of whether the currently applied policy instruments act in synchrony in mitigating eutrophication caused by N and P versus DOM load. DOM is a complex mixture of compounds that are poorly characterized. DOM export is strongly regulated by land use (urban, forest, agricultural land, peat land), in addition to soil type and soil organic carbon concentration. Furthermore, the composition of DOM varies according to its origin. The fate and effects of DOM loads in the fresh water and coastal environments depend, for example, on their biodegradability. Degradation kinetics again depends on the interactions between composition of the DOM pool and the receiving environment. Impact studies of dissolved organic matter pose a complicated environmental impact assessment challenge for science. There exists strategic uncertainty in the science about the causal dependencies and about the quality of knowledge related to DOM. There is a clear need for systematization in the approach as uncertainty is typically high about many key processes. A cross-sectorial, integrative analysis will aid in focusing on the most relevant issues. A holistic and unambiguous analysis will provide support for policy-decisions and management by indicating which outcome is more probable than another. The task requires coupling complex models of different environmental compartments (soil chemistry, agricultural management practices, aquatic processes, costs and benefits for society) with explicit treatment of uncertainty. In order to achieve policy relevance, these models have to be integrated into resource management. We use a Bayesian belief net to describe the probabilistic dependencies among the driving forces, processes, and impacts relevant to dissolved organic matter in boreal waterways.

Decomposition and biodegradability enhancement of textile wastewater using a combination of electron beam irradiation and activated sludge process.

PubMed

Mohd Nasir, Norlirubayah; Teo Ming, Ting; Ahmadun, Fakhru'l-Razi; Sobri, Shafreeza

2010-01-01

The research conducted a study on decomposition and biodegradability enhancement of textile wastewater using a combination of electron beam irradiation and activated sludge process. The purposes of this research are to remove pollutant through decomposition and to enhance the biodegradability of textile wastewater. The wastewater is treated using electron beam irradiation as a pre-treatment before undergo an activated sludge process. As a result, for non-irradiated wastewater, the COD removal was achieved to be between 70% and 79% after activated sludge process. The improvement of COD removal efficiency increased to 94% after irradiation of treated effluent at the dose of 50 kGy. Meanwhile, the BOD(5) removal efficiencies of non-irradiated and irradiated textile wastewater were reported to be between 80 and 87%, and 82 and 99.2%, respectively. The maximum BOD(5) removal efficiency was achieved at day 1 (HRT 5 days) of the process of an irradiated textile wastewater which is 99.2%. The biodegradability ratio of non-irradiated wastewater was reported to be between 0.34 and 0.61, while the value of biodegradability ratio of an irradiated wastewater increased to be between 0.87 and 0.96. The biodegradability enhancement of textile wastewater is increased with increasing the doses. Therefore, an electron beam radiation holds a greatest application of removing pollutants and also on enhancing the biodegradability of textile wastewater.

Potential for enhancement of aerobic biological removal of recalcitrant organic matter in bleached pulp mill effluents.

PubMed

Mounteer, A H; Souza, L C; Silva, C M

2007-02-01

Increasingly stringent effluent quality limits for bleached kraft pulp mills pose a great challenge to mill wastewater system managers since these limits can require levels of chemical oxygen demand (COD) removal efficiency rarely reported for biological treatment of these types of effluents. The present study was therefore undertaken to better understand the nature of recalcitrant COD in bleached kraft pulp effluents that persists through the biological treatment system. Bleaching effluents from a Brazilian eucalypt bleached kraft pulp mill were collected and treated in a bench-scale sequencing batch reactor. Organic matter in raw and treated effluents was characterized before and after separation into low and high molecular mass fractions. Biological treatment removed 71% of the COD, with 83% removal of the low molecular mass COD but only 36% removal of the high molecular mass COD. Microorganisms capable of degrading the recalcitrant COD were isolated from enrichment cultures of the original activated sludge fed on fractions of the bleaching effluent that presented low biodegradabilities. Use of a microbial consortium composed of ten of these isolates to treat the biologically treated effluent removed a further 12% of the effluent COD, all from the high molecular mass fraction. Results of this research indicate that microorganisms with potential for degrading recalcitrant COD are present in activated sludge, but that these are not metabolically active during normal activated sludge treatment of mill effluents. The use of biological selectors in the treatment system to promote growth of such microorganisms may enhance removal of recalcitrant organic matter.

Control of Biofouling using Biodegradable Natural Products

DTIC Science & Technology

2002-10-01

Hydroxylated aromatic acids are also known fungicides. An example of this is the production of protocatechuic acid by Allium sativum (garlic). The...copper, zinc ), non-biodegradable, or difficult/costly to use (peroxides, ozone). In addition, the potential of unintentional negative impact on non

A biodegradation study of forest biomass by Aspergillus niger F7: correlation between enzymatic activity, hydrolytic percentage and biodegradation index

PubMed Central

Sharma, Nivedita; Kaushal, Richa; Gupta, Rakesh; Kumar, Sanjeev

2012-01-01

Aspergillus niger F7 isolated from soil was found to be the potent producer of cellulase and xylanase. The residue of forest species Toona ciliata, Celtris australis, Cedrus deodara and Pinus roxburghii was selected as substrate for biodegradation study due to its easy availability and wide use in industry. It was subjected to alkali (sodium hydroxide) treatment for enhancing its degradation. Biodegradation of forest waste by hydrolytic enzymes (cellulase and xylanase) secreted by A. niger under solid state fermentation (SSF) was explored. SSF of pretreated forest biomass was found to be superior over untreated forest biomass. Highest extracellular enzyme activity of 2201±23.91 U/g by A. niger was shown in pretreated C. australis wood resulting in 6.72±0.20 percent hydrolysis and 6.99±0.23 biodegradation index (BI). The lowest BI of 1.40±0.08 was observed in untreated saw dust of C. deodara having the least enzyme activity of 238±1.36 U/g of dry matter. Biodegradation of forest biomass under SSF was increased many folds when moistening agent i.e. tap water had been replaced with modified basal salt media (BSM). In BSM mediated degradation of forest waste with A. niger, extracellular enzyme activity was increased up to 4089±67.11 U/g of dry matter in turn resulting in higher BI of 15.4±0.41 and percent hydrolysis of 19.38±0.81 in pretreated C. australis wood. A. niger exhibited higher enzyme activity on pretreated biomass when moistened with modified BSM in this study. Statistically a positive correlation has been drawn between these three factors i.e. enzyme activity, BI and percent hydrolysis of forest biomass thus proving their direct relationship with each other. PMID:24031853

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.

Enhancing the biological degradability of sulfamethoxazole by ionizing radiation treatment in aqueous solution

NASA Astrophysics Data System (ADS)

Sági, Gyuri; Kovács, Krisztina; Bezsenyi, Anikó; Csay, Tamás; Takács, Erzsébet; Wojnárovits, László

2016-07-01

Changes of biodegradability and toxicity were followed up on aqueous solutions of sulfamethoxazole (SMX), during ionizing radiation treatment. The biodegradability of SMX (0.1 mmol dm-3) was specified by five-day biological oxygen demand (BOD5), using municipal activated sludge, and the results showed an improvement with applying only 0.4 kGy dose. BOD5 further increased with prolonged irradiation, indicating a conversion of SMX, a non-biodegradable compound, to biologically treatable substances. At 2.5 kGy dose, the BOD5/COD ratio increased from 0 to 0.16. The total organic carbon (TOC) content showed a decrease of only 15% at this point, thus high degree of mineralization is not necessary to make SMX digestible for the low concentrations of microorganisms used during BOD5 measurements. Increment in respiration inhibition of municipal activated sludge was observed with increasing the dose. The EC50 values showed a decrease of one order of magnitude when changing the dose from 0.4 kGy to 2.5 kGy. The increase of inhibition and formation of H2O2 showed a strong correlation.

Energy performance of an integrated bio-and-thermal hybrid system for lignocellulosic biomass waste treatment.

PubMed

Kan, Xiang; Yao, Zhiyi; Zhang, Jingxin; Tong, Yen Wah; Yang, Wenming; Dai, Yanjun; Wang, Chi-Hwa

2017-03-01

Lignocellulosic biomass waste, a heterogeneous complex of biodegradables and non-biodegradables, accounts for large proportion of municipal solid waste. Due to limitation of single-stage treatment, a two-stage hybrid AD-gasification system was proposed in this work, in which AD acted as pre-treatment to convert biodegradables into biogas followed by gasification converting solid residue into syngas. Energy performance of single and two-stage systems treating 3 typical lignocellulosic wastes was studied using both experimental and numerical methods. In comparison with conventional single-stage gasification treatment, this hybrid system could significantly improve the quality of produced gas for all selected biomass wastes and show its potential in enhancing total gas energy production by a maximum value of 27% for brewer's spent grain treatment at an organic loading rate (OLR) of 3gVS/L/day. The maximum overall efficiency of the hybrid system for horticultural waste treatment was 75.2% at OLR of 11.3gVS/L/day, 5.5% higher than conventional single-stage system. Copyright © 2016 Elsevier Ltd. All rights reserved.

Application of H2O and UV/H2O2 processes for enhancing the biodegradability of reactive black 5 dye.

PubMed

Kalpana, S Divya; Kalyanaraman, Chitra; Gandhi, N Nagendra

2011-07-01

Leather processing is a traditional activity in India during which many organic and inorganic chemicals are added while part of it is absorbed by the leather, the remaining chemicals are discharged along with the effluent. The effluent contains both easily biodegradable and not easily biodegradable synthetic organics like dyes, syntans. Easily biodegradable organics are removed in the existing biological treatment units whereas synthetic organics present in the wastewater are mostly adsorbed over the microbes. As the tannery effluent contains complex chemicals, it is difficult to ascertain the degradation of specific pollutants. To determine the increase in the biodegradability, one of the complex and synthetic organic chemical like dye used in the tanning operation was selected for Advanced Oxidation Process (AOPs) treatment for cleaving complex organics and its subsequent treatment in aerobic process. In the present study, Reactive Black 5 Dye used in the tanning operation was selected for Hydrogen Peroxide (H2O2) and UV/H2O2 pre-treatment for different operating conditions like pH, contact time and different volume of H2O2. A comparison was made between the untreated, Hydrogen Peroxide (H2O2) and UV/H2O2 treated effluent in order to ascertain the influence of AOP on the improvement of biodegradability of effluent. An increase in the BOD5/COD ratio from 0.21 to 0.435 was achieved in the UV/H2O2 pre-treatment process. This pre-treated effluent was further subjected to aerobic process. Biochemical Oxygen Demand (BOD5) and Chemical Oxygen Demand (COD) removal efficiency of the UV/H2O2 pre-treated dye solution in the aerobic process was found to be 86.39% and 77.82% when compared to 52.43% of BOD5 and 51.55% of COD removal efficiency without any pre-treatment. Hence from these results, to increase the biodegradability of Reactive Black 5 dye pre-treatment methods like H2O2 and UV/H2O2 can be used prior to biological treatment process.

Sorption, transport and biodegradation - An insight into bioavailability of persistent organic pollutants in soil.

PubMed

Ren, Xiaoya; Zeng, Guangming; Tang, Lin; Wang, Jingjing; Wan, Jia; Liu, Yani; Yu, Jiangfang; Yi, Huan; Ye, Shujing; Deng, Rui

2018-01-01

Contamination of soils with persistent organic pollutants (POPs), such as organochlorine pesticide, polybrominated diphenyl ethers, halohydrocarbon, polycyclic aromatic hydrocarbons (PAHs) is of increasing concern. Microbial degradation is potential mechanism for the removal of POPs, but it is often restricted by low bioavailability of POPs. Thus, it is important to enhance bioavailability of POPs in soil bioremediation. A series of reviews on bioavailability of POPs has been published in the past few years. However, bioavailability of POPs in relation to soil organic matter, minerals and soil microbes has been little studied. To fully understand POPs bioavailability in soil, research on interactions of POPs with soil components and microbial responses in bioavailability limitation conditions are needed. This review focuses on bioavailability mechanisms of POPs in terms of sorption, transport and microbial adaptation, which is particularly novel. In consideration of the significance of bioavailability, further studies should investigate the influence of various bioremediation strategies on POPs bioavailability. Copyright © 2017 Elsevier B.V. All rights reserved.

Impact of the excess sludge modification with selected chemical reagents on the increase of dissolved organic substances concentration compounds transformations in activated sludge.

PubMed

Zawieja, Iwona; Lidia, Wolny; Marta, Próba

2017-07-01

Submission of excess sludge initial disintegration process significantly affects the efficiency of anaerobic stabilization process. Expression of increasing the concentration of organic matter in dissolved form is to increase sludge disintegration. As a result of chemical modification is an increase of the chemical oxygen demand and the concentration of volatile fatty acids. The aim of this study was to determine the impact of the disintegration process with selected chemical reagents to increase the concentration of organic substances in dissolved form. The process of chemical disintegration of excess sludge was treated using the following reagents: Mg(OH) 2 , Ca(OH) 2 , HCl, H 2 SO 4 , H 2 O 2 . The modification was carried out at ambient temperature for 2, 6 and 24h. During sludge disintegration it was noticed the growth of indicators values that confirmed the susceptibility of prepared sludge to biodegradation. Copyright © 2017 Elsevier Inc. All rights reserved.

Ingestion and fragmentation of plastic carrier bags by the amphipod Orchestia gammarellus: Effects of plastic type and fouling load.

PubMed

Hodgson, D J; Bréchon, A L; Thompson, R C

2018-02-01

Inappropriate disposal of plastic debris has led to the contamination of marine habitats worldwide. This debris can be ingested by organisms; however, the extent to which chewing and gut transit modifies plastic debris is unclear. Detritivores, such as amphipods, ingest and shred natural organic matter and are fundamental to its breakdown. Here we examine ingestion and shredding of plastic carrier bags by Orchestia gammarellus. A laboratory experiment showed these amphipods shredded plastic carrier bags, generating numerous microplastic fragments (average diameter 488.59μm). The presence of a biofilm significantly increased the amount of shredding, but plastic type (conventional, degradable and biodegradable) had no effect. Subsequent field observations confirmed similar shredding occurred on the strandline. Rates of shredding will vary according to amphipod density; however, our data indicates that shredding by organisms could substantially accelerate the formation microplastics in the environment. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

The Effects of Permafrost Thaw on Organic Matter Quality and Availability Along a Hill Slope in Northeastern Siberia

NASA Astrophysics Data System (ADS)

Connolly, C. T.; Spawn, S.; Ludwig, S.; Schade, J. D.; Natali, S.

2014-12-01

Climate warming and permafrost thaw in northeastern Siberia are expected to change the quantity and quality of organic matter (OM) transported through watersheds, releasing previously frozen carbon (C) to biologically available pool. Hill slopes have shown to influence the distribution of OM, resulting in a downhill accumulation of available C and nutrients relative to uphill. Here we examine how future permafrost thaw will change OM quality and availability along a hill slope in a larch-dominated watershed. We collected soils from the thawed organic and mineral layers, and 1m deep permafrost cores for dissolved organic C (DOC) and total dissolved N (TDN), C composition from measures of colored dissolved organic matter (CDOM), DOC lability from biodegradable DOC (BDOC) incubations, C and nutrient availability from extracellular-enzyme assays (EEA's), and microbial respiration from aerobic soil incubations. Here we show that organic soils (O), in comparison to mineral soils (M) and permafrost (P) are the most abundant source of C (avg O DOC: 51.6mg/L), exhibiting low molecular complexity (avg O SUVA254: 4.05) and high quality. Evidence suggests permafrost OM may be an equally abundant, and more labile source of C than mineral soils (highest P DOC: 16.1 mg/L, lowest P SUVA254: 6.32; median M DOC: 18.5 mg/L, median M SUVA254: 24.0). Furthermore, we demonstrate that there may be a positive relationship in the rate of C mineralization and distance downhill, showing 15-30% greater CO2 production/gC downhill relative to uphill. Evidence also supports a similar relationship in permafrost DOC content and molecular complexity, showing more DOC of a lower complexity further downhill. This indicates DOC transport may have been occurring through the active layer and downhill during ice-rich permafrost formation, and may supply a labile source of carbon to lowland areas and adjacent stream networks upon thaw.

Surface tension and wetting properties of rapeseed oil to biofuel conversion by-products

NASA Astrophysics Data System (ADS)

Muszyński, Siemowit; Sujak, Agnieszka; Stępniewski, Andrzej; Kornarzyński, Krzysztof; Ejtel, Marta; Kowal, Natalia; Tomczyk-Warunek, Agnieszka; Szcześniak, Emil; Tomczyńska-Mleko, Marta; Mleko, Stanisław

2018-04-01

This work presents a study on the surface tension, density and wetting behaviour of distilled glycerol, technical grade glycerol and the matter organic non-glycerin fraction. The research was conducted to expand the knowledge about the physical properties of wastes from the rapeseed oil biofuel production. The results show that the densities of technical grade glycerol (1.300 g cm-3) and distilled glycerol (1.267 g cm-3) did not differ and were significantly lower than the density of the matter organic non-glycerin fraction (1.579 g cm-3). Furthermore, the surface tension of distilled glycerol (49.6 mN m-1) was significantly higher than the matter organic non-glycerin fraction (32.7 mN m-1) and technical grade glycerol (29.5 mN m-1). As a result, both technical grade glycerol and the matter organic non-glycerin fraction had lower contact angles than distilled glycerol. The examined physical properties of distilled glycerol were found to be very close to that of the commercially available pure glycerol. The results suggest that technical grade glycerol may have potential application in the production of glycerol/fuel blends or biosurfactants. The presented results indicate that surface tension measurements are more useful when examining the quality of biofuel wastes than is density determination, as they allow for a more accurate analysis of the effects of impurities on the physical properties of the biofuel by-products.

Biodegradable Plastic Mulch Films: Impacts on Soil Microbial Communities and Ecosystem Functions.

PubMed

Bandopadhyay, Sreejata; Martin-Closas, Lluis; Pelacho, Ana M; DeBruyn, Jennifer M

2018-01-01

Agricultural plastic mulch films are widely used in specialty crop production systems because of their agronomic benefits. Biodegradable plastic mulches (BDMs) offer an environmentally sustainable alternative to conventional polyethylene (PE) mulch. Unlike PE films, which need to be removed after use, BDMs are tilled into soil where they are expected to biodegrade. However, there remains considerable uncertainty about long-term impacts of BDM incorporation on soil ecosystems. BDMs potentially influence soil microbial communities in two ways: first, as a surface barrier prior to soil incorporation, indirectly affecting soil microclimate and atmosphere (similar to PE films) and second, after soil incorporation, as a direct input of physical fragments, which add carbon, microorganisms, additives, and adherent chemicals. This review summarizes the current literature on impacts of plastic mulches on soil biological and biogeochemical processes, with a special emphasis on BDMs. The combined findings indicated that when used as a surface barrier, plastic mulches altered soil microbial community composition and functioning via microclimate modification, though the nature of these alterations varied between studies. In addition, BDM incorporation into soil can result in enhanced microbial activity and enrichment of fungal taxa. This suggests that despite the fact that total carbon input from BDMs is minuscule, a stimulatory effect on microbial activity may ultimately affect soil organic matter dynamics. To address the current knowledge gaps, long term studies and a better understanding of impacts of BDMs on nutrient biogeochemistry are needed. These are critical to evaluating BDMs as they relate to soil health and agroecosystem sustainability.

Organic biowastes blend selection for composting industrial eggshell by-product: experimental and statistical mixture design.

PubMed

Soares, Micaela A R; Andrade, Sandra R; Martins, Rui C; Quina, Margarida J; Quinta-Ferreira, Rosa M

2012-01-01

Composting is one of the technologies recommended for pre-treating industrial eggshells (ES) before its application in soils, for calcium recycling. However, due to the high inorganic content of ES, a mixture of biodegradable materials is required to assure a successful procedure. In this study, an adequate organic blend composition containing potato peel (PP), grass clippings (GC) and wheat straw (WS) was determined by applying the simplex-centroid mixture design method to achieve a desired moisture content, carbon: nitrogen ratio and free air space for effective composting of ES. A blend of 56% PP, 37% GC and 7% WS was selected and tested in a self heating reactor, where 10% (w/w) of ES was incorporated. After 29 days of reactor operation, a dry matter reduction of 46% was achieved and thermophilic temperatures were maintained during 15 days, indicating that the blend selected by statistical approach was adequate for composting of ES.

Enhancing Potentially Plant-Available Lead Concentrations in Contaminated Residential Soils Using a Biodegradable Chelating Agent

NASA Astrophysics Data System (ADS)

Andra, S.; Datta, R.; Sarkar, D.; Saminathan, S.

2007-12-01

Chelation of heavy metals is an important factor in enhancing metal solubility and, hence, metal availability to plants to promote phytoremediation. In the present study, we compared the effects of application of a biodegradable chelating agent, namely, ethylenediaminedisuccinic acid (EDDS) on enhancing plant available form of lead (Pb) in Pb-based paint contaminated residential soils compared to that of a more commonly used, but non-biodegradable chelate, i.e., ethylenediaminetetraacetic acid (EDTA). Development of a successful phytoremediation model for metals such as Pb depends on a thorough understanding of the physical and chemical properties of the soil, along with the optimization of a chelate treatment to mobilize Pb from `unavailable' pools to potentially plant available fraction. In this context, we set out to perform batch incubation experiments to investigate the effectiveness of the two aforementioned chelates in enhancing plant available Pb at four different concentrations (0, 5, 10 and 15 mM/kg soil) and three treatment durations (0, 10 and 30 days). We selected 12 contaminated residential soils from two major metropolitan areas (San Antonio, TX and Baltimore, MD) with varying soil physico-chemical properties - the soils from San Antonio were primarily alkaline and those from Baltimore were typically acidic. Total soil Pb concentrations ranged between 256 mg/kg and 4,182 mg/kg. Our results show that both chelates increased the solubility of Pb, otherwise occluded in the complex soil matrix. For both EDTA and EDDS, the exchangeable concentrations of soil Pb also increased with increase in chelate concentration and incubation time. The most effective treatment was 15 mM chelate kg-1 soil incubated for 30 days, which caused many fold increase in potentially plant available Pb (a combination of the soluble and exchangeable fractions) relative to the unamended controls. Step wise multiple linear regression analysis using chelate-extractable Pb and soil properties showed that plant available Pb fraction could be assessed from the two inter-related soil parameters: soil organic matter and soil pH. Although EDTA was more effective in Pb solubilization than EDDS, the rapid kinetics of the Pb-EDTA complexation process and the prolonged persistence of EDTA in soils pose a potential groundwater contamination problem via metal leaching. In contrast to EDTA, EDDS addition caused relatively slow release of Pb from the soil matrix. The biodegradable nature (and short half life) of EDDS in soils makes it a promising chelating agent for use as soil amendment to enhance Pb solubilization and hence, potential plant uptake.

What is soil organic matter worth?

PubMed

Sparling, G P; Wheeler, D; Vesely, E-T; Schipper, L A

2006-01-01

The conservation and restoration of soil organic matter are often advocated because of the generally beneficial effects on soil attributes for plant growth and crop production. More recently, organic matter has become important as a terrestrial sink and store for C and N. We have attempted to derive a monetary value of soil organic matter for crop production and storage functions in three contrasting New Zealand soil orders (Gley, Melanic, and Granular Soils). Soil chemical and physical characteristics of real-life examples of three pairs of matched soils with low organic matter contents (after long-term continuous cropping for vegetables or maize) or high organic matter content (continuous pasture) were used as input data for a pasture (grass-clover) production model. The differences in pasture dry matter yields (non-irrigated) were calculated for three climate scenarios (wet, dry, and average years) and the yields converted to an equivalent weight and financial value of milk solids. We also estimated the hypothetical value of the C and N sequestered during the recovery phase of the low organic matter content soils assuming trading with C and N credits. For all three soil orders, and for the three climate scenarios, pasture dry matter yields were decreased in the soils with lower organic matter contents. The extra organic matter in the high C soils was estimated to be worth NZ$27 to NZ$150 ha(-1) yr(-1) in terms of increased milk solids production. The decreased yields from the previously cropped soils were predicted to persist for 36 to 125 yr, but with declining effect as organic matter gradually recovered, giving an accumulated loss in pastoral production worth around NZ$518 to NZ$1239 ha(-1). This was 42 to 73 times lower than the hypothetical value of the organic matter as a sequestering agent for C and N, which varied between NZ$22,963 to NZ$90,849 depending on the soil, region, discount rates, and values used for carbon and nitrogen credits.

Fate and transport of monoterpenes through soils. Part II: calculation of the effect of soil temperature, water saturation and organic carbon content.

PubMed

van Roon, André; Parsons, John R; Krap, Lenny; Govers, Harrie A J

2005-09-01

This theoretical study was performed to investigate the influence of soil temperature, soil water content and soil organic carbon fraction on the mobility of monoterpenes (C10HnOn') applied as pesticides to a top soil layer. This mobility was expressed as the amount volatilized and leached from the contaminated soil layer after a certain amount of time. For this, (slightly modified) published analytical solutions to a one dimensional, homogeneous medium, diffusion/advection/biodegradation mass balance equation were used. The required input-parameters were determined in a preceding study. Because the monoterpenes studied differ widely in the values for their physico-chemical properties, the relative importance of the various determinants also differed widely. Increasing soil water saturation reduced monoterpene vaporization and leaching losses although a modest increase was usually observed at high soil water contents. Organic matter served as the major retention domain, reducing volatilization and leaching losses. Increasing temperature resulted in higher volatilization and leaching losses. Monoterpene mobility was influenced by vertical water flow. Volatilization losses could be reduced by adding a clean soil layer on top of the contaminated soil. Detailed insight into the specific behaviour of different monoterpenes was obtained by discussing intermediate calculation results; the transport retardation factors and effective soil diffusion coefficients. One insight was that the air-water interface compartment is probably not an important partitioning domain for monoterpenes in most circumstances. The results further indicated that biodegradation is an important process for monoterpenes in soil.

Sub-soil microbial activity under rotational cotton crops in Australia

NASA Astrophysics Data System (ADS)

Polain, Katherine; Knox, Oliver; Wilson, Brian; Pereg, Lily

2016-04-01

Soil microbial communities contribute significantly to soil organic matter formation, stabilisation and destabilisation, through nutrient cycling and biodegradation. The majority of soil microbial research examines the processes occurring in the top 0 cm to 30 cm of the soil, where organic nutrients are easily accessible. In soils such as Vertosols, the high clay content causes swelling and cracking. When soil cracking is coupled with rain or an irrigation event, a flush of organic nutrients can move down the soil profile, becoming available for subsoil microbial community use and potentially making a significant contribution to nutrient cycling and biodegradation in soils. At present, the mechanisms and rates of soil nutrient turnover (such as carbon and nitrogen) at depth under cotton rotations are mostly speculative and the process-response relationships remain unclear, although they are undoubtedly underpinned by microbial activity. Our research aims to determine the contribution and role of soil microbiota to the accumulation, cycling and mineralisation of carbon and nitrogen through the whole root profile under continuous cotton (Gossypium hirsutum) and cotton-maize rotations in regional New South Wales, Australia. Through seasonal work, we have established both baseline and potential microbial activity rates from 0 cm to 100 cm down the Vertosol profile, using respiration and colourimetric methods. Further whole soil profile analyses will include determination of microbial biomass and isotopic carbon signatures using phospholipid fatty acid (PLFA) methodology, identification of microbial communities (sequencing) and novel experiments to investigate potential rates of nitrogen mineralisation and quantification of associated genes. Our preliminary observations and the hypotheses tested in this three-year study will be presented.

78 FR 52100 - National Organic Program; Proposed Amendments to the National List of Allowed and Prohibited...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-22

... least 90% biodegradation absolute or relative to microcrystalline cellulose in less than two years, in... standards for compostability, biodegradation, and biobased content be included at subparagraph (b)(2)(iii...% biodegradation absolute or relative to microcrystalline cellulose in less than two years, in soil, according to...

40 CFR 98.464 - Monitoring and QA/QC requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) Determine DOC value of a waste stream by either using at least a 60-day anaerobic biodegradation test as... biodegradation test and determine the DOC value of a waste stream following the procedures and requirements in...-based standards organization to conduct a minimum of a 60-day anaerobic biodegradation test. Consensus...

Enhanced hydrolysis and methane yield by applying microaeration pretreatment to the anaerobic co-digestion of brown water and food waste

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

Lim, Jun Wei; School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798; Wang, Jing-Yuan, E-mail: jywang@ntu.edu.sg

2013-04-15

Highlights: ► Microaeration pretreatment was effective for brown water and food waste mixture. ► The added oxygen was consumed fully by facultative microorganisms. ► Enhanced solubilization, acidification and breakdown of SCFAs to acetate. ► Microaeration pretreatment improved methane yield by 10–21%. ► Nature of inoculum influenced the effects of microaeration. - Abstract: Microaeration has been used conventionally for the desulphurization of biogas, and recently it was shown to be an alternative pretreatment to enhance hydrolysis of the anaerobic digestion (AD) process. Previous studies on microaeration pretreatment were limited to the study of substrates with complex organic matter, while little hasmore » been reported on its effect on substrates with higher biodegradability such as brown water and food waste. Due to the lack of consistent microaeration intensities, previous studies were not comparable and thus inconclusive in proving the effectiveness of microaeration to the overall AD process. In this study, the role of microaeration pretreatment in the anaerobic co-digestion of brown water and food waste was evaluated in batch-tests. After a 4-day pretreatment with 37.5 mL-O{sub 2}/L{sub R}-d added to the liquid phase of the reactor, the methane production of substrates were monitored in anaerobic conditions over the next 40 days. The added oxygen was consumed fully by facultative microorganisms and a reducing environment for organic matter degradation was maintained. Other than higher COD solubilization, microaeration pretreatment led to greater VFA accumulation and the conversion of other short chain fatty acids to acetate. This could be due to enhanced activities of hydrolytic and acidogenic bacteria and the degradation of slowly biodegradable compounds under microaerobic conditions. This study also found that the nature of inoculum influenced the effects of microaeration as a 21% and 10% increase in methane yield was observed when pretreatment was applied to inoculated substrates, and substrates without inoculum, respectively.« less

Use of Organic Substrates as a Best Management Practice for Active Ranges

DTIC Science & Technology

2011-11-30

is much more limited in high organic carbon soils due to a combination of enhanced sorption and degradation . Organic materials can enhance explosive... degradation by stimulating anaerobic biodegradation of the target contaminants and reducing naturally occurring Fe(III) to Fe(II), providing a reservoir...of reducing power to maintain anoxic conditions in the soil and enhance abiotic degradation . Humic materials slowly biodegrade, consuming oxygen

Photoconversion of gasified organic materials into biologically-degradable plastics

DOEpatents

Weaver, P.F.; Pinching Maness.

1993-10-05

A process is described for converting organic materials (such as biomass wastes) into a bioplastic suitable for use as a biodegradable plastic. In a preferred embodiment the process involves thermally gasifying the organic material into primarily carbon monoxide and hydrogen, followed by photosynthetic bacterial assimilation of the gases into cell material. The process is ideally suited for waste recycling and for production of useful biodegradable plastic polymer. 3 figures.

Photoconversion of gasified organic materials into biologically-degradable plastics

DOEpatents

Weaver, Paul F.; Maness, Pin-Ching

1993-01-01

A process is described for converting organic materials (such as biomass wastes) into a bioplastic suitable for use as a biodegradable plastic. In a preferred embodiment the process involves thermally gasifying the organic material into primarily carbon monoxide and hydrogen, followed by photosynthetic bacterial assimilation of the gases into cell material. The process is ideally suited for waste recycling and for production of useful biodegradable plastic polymer.

Biodegradation of paint stripper solvents in a modified gas lift loop bioreactor.

PubMed

Vanderberg-Twary, L; Steenhoudt, K; Travis, B J; Hanners, J L; Foreman, T M; Brainard, J R

1997-07-05

Paint stripping wastes generated during the decontamination and decommissioning of former nuclear facilities contain paint stripping organics (dichloromethane, 2-propanol, and methanol) and bulk materials containing paint pigments. It is desirable to degrade the organic residues as part of an integrated chemical-biological treatment system. We have developed a modified gas lift loop bioreactor employing a defined consortium of Rhodococcus rhodochrous strain OFS and Hyphomicrobium sp. DM-2 that degrades paint stripper organics. Mass transfer coefficients and kinetic constants for biodegradation in the system were determined. It was found that transfer of organic substrates from surrogate waste into the air and further into the liquid medium in the bioreactor were rapid processes, occurring within minutes. Monod kinetics was employed to model the biodegradation of paint stripping organics. Analysis of the bioreactor process was accomplished with BIOLAB, a mathematical code that simulates coupled mass transfer and biodegradation processes. This code was used to fit experimental data to Monod kinetics and to determine kinetic parameters. The BIOLAB code was also employed to compare activities in the bioreactor of individual microbial cultures to the activities of combined cultures in the bioreactor. This code is of benefit for further optimization and scale-up of the bioreactor for treatment of paint stripping and other volatile organic wastes in bulk materials.

40 CFR 88.103-94 - Abbreviations.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Vehicle LDT—Light-Duty Truck LDV—Light-Duty Vehicle NMHC—Non-Methane Hydrocarbon NMHCE—Non-Methane Hydrocarbon Equivalent NMOG—Non-Methane Organic Gas NOx—Nitrogen Oxides PM—Particulate Matter GVWR—Gross...

40 CFR 88.103-94 - Abbreviations.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Vehicle LDT—Light-Duty Truck LDV—Light-Duty Vehicle NMHC—Non-Methane Hydrocarbon NMHCE—Non-Methane Hydrocarbon Equivalent NMOG—Non-Methane Organic Gas NOx—Nitrogen Oxides PM—Particulate Matter GVWR—Gross...

40 CFR 88.103-94 - Abbreviations.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Vehicle LDT—Light-Duty Truck LDV—Light-Duty Vehicle NMHC—Non-Methane Hydrocarbon NMHCE—Non-Methane Hydrocarbon Equivalent NMOG—Non-Methane Organic Gas NOx—Nitrogen Oxides PM—Particulate Matter GVWR—Gross...

40 CFR 88.103-94 - Abbreviations.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Vehicle LDT—Light-Duty Truck LDV—Light-Duty Vehicle NMHC—Non-Methane Hydrocarbon NMHCE—Non-Methane Hydrocarbon Equivalent NMOG—Non-Methane Organic Gas NOx—Nitrogen Oxides PM—Particulate Matter GVWR—Gross...

40 CFR 88.103-94 - Abbreviations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Vehicle LDT—Light-Duty Truck LDV—Light-Duty Vehicle NMHC—Non-Methane Hydrocarbon NMHCE—Non-Methane Hydrocarbon Equivalent NMOG—Non-Methane Organic Gas NOx—Nitrogen Oxides PM—Particulate Matter GVWR—Gross...

Pollution profile and biodegradation characteristics of fur-suede processing effluents.

PubMed

Yildiz Töre, G; Insel, G; Ubay Cokgör, E; Ferlier, E; Kabdaşli, I; Orhon, D

2011-07-01

This study investigated the effect of stream segregation on the biodegradation characteristics of wastewaters generated by fur-suede processing. It was conducted on a plant located in an organized industrial district in Turkey. A detailed in-plant analysis of the process profile and the resulting pollution profile in terms of significant parameters indicated the characteristics of a strong wastewater with a maximum total COD of 4285 mg L(-1), despite the excessive wastewater generation of 205 m3 (ton skin)(-1). Respirometric analysis by model calibration yielded slow biodegradation kinetics and showed that around 50% of the particulate organics were utilized at a rate similar to that of endogenous respiration. A similar analysis on the segregated wastewater streams suggested that biodegradation of the plant effluent is controlled largely by the initial washing/pickling operations. The effect of other effluent streams was not significant due to their relatively low contribution to the overall organic load. The respirometric tests showed that the biodegradation kinetics of the joint treatment plant influent of the district were substantially improved and exhibited typical levels reported for tannery wastewater, so that the inhibitory impact was suppressed to a great extent by dilution and mixing with effluents of the other plants. The chemical treatment step in the joint treatment plant removed the majority of the particulate organics so that 80% of the available COD was utilized in the oxygen uptake rate (OUR) test, a ratio quite compatible with the biodegradable COD fractions of tannery wastewater. Consequently, process kinetics and especially the hydrolysis rate appeared to be significantly improved.

28 CFR 0.26 - Organization.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Administration DEPARTMENT OF JUSTICE ORGANIZATION OF THE DEPARTMENT OF JUSTICE 1-Office of International Programs... Deputy Attorney General with officials of foreign governments, foreign non-governmental organizations, and international organizations. (5) As required, advise the Deputy Attorney General on matters...

Microbial control of the dark end of the biological pump

PubMed Central

2014-01-01

A fraction of the carbon captured by phytoplankton in the sunlit surface ocean sinks to depth as dead organic matter and faecal material. The microbial breakdown of this material in the subsurface ocean generates carbon dioxide. Collectively, this microbially mediated flux of carbon from the atmosphere to the ocean interior is termed the biological pump. In recent decades it has become clear that the composition of the phytoplankton community in the surface ocean largely determines the quantity and quality of organic matter that sinks to depth. This settling organic matter, however, is not sufficient to meet the energy demands of microbes in the dark ocean. Two additional sources of organic matter have been identified: non-sinking organic particles of debated origin that escape capture by sediment traps and exhibit stable concentrations throughout the dark ocean, and microbes that convert inorganic carbon into organic matter. Whether these two sources can together account for the significant mismatch between organic matter consumption and supply in the dark ocean remains to be seen. It is clear, however, that the microbial community of the deep ocean works in a fundamentally different way from surface water communities. PMID:24707320

Dissolved organic carbon and nitrogen release from boreal Holocene permafrost and seasonally frozen soils of Alaska

NASA Astrophysics Data System (ADS)

Wickland, Kimberly P.; Waldrop, Mark P.; Aiken, George R.; Koch, Joshua C.; Torre Jorgenson, M.; Striegl, Robert G.

2018-06-01

Permafrost (perennially frozen) soils store vast amounts of organic carbon (C) and nitrogen (N) that are vulnerable to mobilization as dissolved organic carbon (DOC) and dissolved organic and inorganic nitrogen (DON, DIN) upon thaw. Such releases will affect the biogeochemistry of permafrost regions, yet little is known about the chemical composition and source variability of active-layer (seasonally frozen) and permafrost soil DOC, DON and DIN. We quantified DOC, total dissolved N (TDN), DON, and DIN leachate yields from deep active-layer and near-surface boreal Holocene permafrost soils in interior Alaska varying in soil C and N content and radiocarbon age to determine potential release upon thaw. Soil cores were collected at three sites distributed across the Alaska boreal region in late winter, cut in 15 cm thick sections, and deep active-layer and shallow permafrost sections were thawed and leached. Leachates were analyzed for DOC, TDN, nitrate (NO3 ‑), and ammonium (NH4 +) concentrations, dissolved organic matter optical properties, and DOC biodegradability. Soils were analyzed for C, N, and radiocarbon (14C) content. Soil DOC, TDN, DON, and DIN yields increased linearly with soil C and N content, and decreased with increasing radiocarbon age. These relationships were significantly different for active-layer and permafrost soils such that for a given soil C or N content, or radiocarbon age, permafrost soils released more DOC and TDN (mostly as DON) per gram soil than active-layer soils. Permafrost soil DOC biodegradability was significantly correlated with soil Δ14C and DOM optical properties. Our results demonstrate that near-surface Holocene permafrost soils preserve greater relative potential DOC and TDN yields than overlying seasonally frozen soils that are exposed to annual leaching and decomposition. While many factors control the fate of DOC and TDN, the greater relative yields from newly thawed Holocene permafrost soils will have the largest potential impact in areas dominated by organic-rich soils.

Evaluation of select blends of cotton byproducts in the manufacture of biodegradable packaging material

USDA-ARS?s Scientific Manuscript database

Polystyrene is one of the most widely used plastics in the manufacture of packaging materials. Extruded polystyrene foam is commonly sold under the trademark name of StyrofoamTM. Polystyrene packaging is a multibillion dollar a year industry. Since polystyrene is non-biodegradable, a biodegradable m...

High-performance green flexible electronics based on biodegradable cellulose nanofibril paper

PubMed Central

Jung, Yei Hwan; Chang, Tzu-Hsuan; Zhang, Huilong; Yao, Chunhua; Zheng, Qifeng; Yang, Vina W.; Mi, Hongyi; Kim, Munho; Cho, Sang June; Park, Dong-Wook; Jiang, Hao; Lee, Juhwan; Qiu, Yijie; Zhou, Weidong; Cai, Zhiyong; Gong, Shaoqin; Ma, Zhenqiang

2015-01-01

Today's consumer electronics, such as cell phones, tablets and other portable electronic devices, are typically made of non-renewable, non-biodegradable, and sometimes potentially toxic (for example, gallium arsenide) materials. These consumer electronics are frequently upgraded or discarded, leading to serious environmental contamination. Thus, electronic systems consisting of renewable and biodegradable materials and minimal amount of potentially toxic materials are desirable. Here we report high-performance flexible microwave and digital electronics that consume the smallest amount of potentially toxic materials on biobased, biodegradable and flexible cellulose nanofibril papers. Furthermore, we demonstrate gallium arsenide microwave devices, the consumer wireless workhorse, in a transferrable thin-film form. Successful fabrication of key electrical components on the flexible cellulose nanofibril paper with comparable performance to their rigid counterparts and clear demonstration of fungal biodegradation of the cellulose-nanofibril-based electronics suggest that it is feasible to fabricate high-performance flexible electronics using ecofriendly materials. PMID:26006731

High-performance green flexible electronics based on biodegradable cellulose nanofibril paper.

PubMed

Jung, Yei Hwan; Chang, Tzu-Hsuan; Zhang, Huilong; Yao, Chunhua; Zheng, Qifeng; Yang, Vina W; Mi, Hongyi; Kim, Munho; Cho, Sang June; Park, Dong-Wook; Jiang, Hao; Lee, Juhwan; Qiu, Yijie; Zhou, Weidong; Cai, Zhiyong; Gong, Shaoqin; Ma, Zhenqiang

2015-05-26

Today's consumer electronics, such as cell phones, tablets and other portable electronic devices, are typically made of non-renewable, non-biodegradable, and sometimes potentially toxic (for example, gallium arsenide) materials. These consumer electronics are frequently upgraded or discarded, leading to serious environmental contamination. Thus, electronic systems consisting of renewable and biodegradable materials and minimal amount of potentially toxic materials are desirable. Here we report high-performance flexible microwave and digital electronics that consume the smallest amount of potentially toxic materials on biobased, biodegradable and flexible cellulose nanofibril papers. Furthermore, we demonstrate gallium arsenide microwave devices, the consumer wireless workhorse, in a transferrable thin-film form. Successful fabrication of key electrical components on the flexible cellulose nanofibril paper with comparable performance to their rigid counterparts and clear demonstration of fungal biodegradation of the cellulose-nanofibril-based electronics suggest that it is feasible to fabricate high-performance flexible electronics using ecofriendly materials.

High-performance green flexible electronics based on biodegradable cellulose nanofibril paper

NASA Astrophysics Data System (ADS)

Jung, Yei Hwan; Chang, Tzu-Hsuan; Zhang, Huilong; Yao, Chunhua; Zheng, Qifeng; Yang, Vina W.; Mi, Hongyi; Kim, Munho; Cho, Sang June; Park, Dong-Wook; Jiang, Hao; Lee, Juhwan; Qiu, Yijie; Zhou, Weidong; Cai, Zhiyong; Gong, Shaoqin; Ma, Zhenqiang

2015-05-01

Today's consumer electronics, such as cell phones, tablets and other portable electronic devices, are typically made of non-renewable, non-biodegradable, and sometimes potentially toxic (for example, gallium arsenide) materials. These consumer electronics are frequently upgraded or discarded, leading to serious environmental contamination. Thus, electronic systems consisting of renewable and biodegradable materials and minimal amount of potentially toxic materials are desirable. Here we report high-performance flexible microwave and digital electronics that consume the smallest amount of potentially toxic materials on biobased, biodegradable and flexible cellulose nanofibril papers. Furthermore, we demonstrate gallium arsenide microwave devices, the consumer wireless workhorse, in a transferrable thin-film form. Successful fabrication of key electrical components on the flexible cellulose nanofibril paper with comparable performance to their rigid counterparts and clear demonstration of fungal biodegradation of the cellulose-nanofibril-based electronics suggest that it is feasible to fabricate high-performance flexible electronics using ecofriendly materials.

Fungal alteration of organic coatings on sand grains

NASA Astrophysics Data System (ADS)

Rothhardt, S.; Gleixner, G.; Benzerara, K.; Fischer, C.; Gaupp, R.

2012-04-01

We studied the fungal alteration of organically coated sand particles, sampled in Eocene sediments in the open cast mining Profen, near Leipzig (Germany). These organic coatings were formed on sand grains after their sedimentation owing to mobilization of organic matter from younger coal layers. The organic coatings formed non-continuous layers on quartz grains, measuring few micrometers up to 30 µm in thickness. It has been shown that organic coatings on sand grains retain efficiently dissolved metals by adsorption from groundwaters. They consequently might be used as adsorbent to purify low heavy metal contaminated water. However, their stability has not been assessed yet especially in the oxic environment and, more specifically, in the presence of microorganisms. This is important in order to evaluate whether coated sands could act as a reliable tool in remediation. In order to address this question we characterized the fungal alteration of organic coatings on sand grains using several techniques, including scanning electron microscopy (SEM), scanning transmission X-ray microscopy (STXM) and vertical scanning interferometry (VSI). Sand grains coated with organics were incubated on complex yeast medium with and without Schizophyllum commune to estimate changes in heavy metal retention. Formation of biominerals and etch pits is induced by fungal colonization as shown by SEM. Surface topography analysis was performed using VSI technique. Etch pit depth ranges from 0.5 to 1 µm. Pit formation is limited to the organic coating; dissolution of quartz grains was not detected. Using STXM we measured near-edge X-ray absorption fine structure (NEXAFS) spectra at the C K-edge, N-edge, and O K-edge to characterize the different organic compartments (fungi, genuine organic coatings, altered organic coatings) down to the 25-nm scale. We observed in the spectra measured at the C K-edge on the altered organic coatings a decrease in aromatic and phenolic groups as well as an enrichment in amide-rich molecules compared to the genuine organic coatings. Our results suggest heterogeneous biodegradation of organic coatings on sand grains by fungal exudation. An important implication might be the overall decrease in metal retention potential of organically coated sand grains owing to the alteration processes by S. commune.

Post fire organic matter biodegradation in permafrost soils: Case study after experimental heating of mineral horizons.

PubMed

Masyagina, O V; Tokareva, I V; Prokushkin, A S

2016-12-15

Periodical ground fires of high frequency in permafrost forest ecosystems of Siberia (Russian Federation) are essential factors determining quantitative and qualitative parameters of permafrost soil organic matter. Specific changes in physical and chemical parameters and microbial activity of permafrost soil mineral horizons of northern taiga larch stands were revealed after heating at high temperatures (150-500°C) used for imitation of different burn intensities. Burning at 150-200°C resulted in decreasing of soil pH, whilst heating at 300-500°C caused increase of pH compare to unheated soils. Water-soluble organic carbon concentration in permafrost soils heated at 150-200°C was much higher than that of unheated soils. All these changes determined soil microbial activity in heated soils. In particular, in soils heated at 300-500°C there was momentary stimulating effect on substrate-induced respiration registered and on basal respiration values in soils burned at 150°C and 300-400°C. Four-month laboratory incubation of permafrost soils heated at different temperatures showed stimulation of microbial activity in first several days after inoculation due to high substrate availability after heating. Then soon after that soil microbial community started to be depleted on substrate because of decreasing water-soluble organic carbon, C and N content and it continued to the end of incubation. Copyright © 2016 Elsevier B.V. All rights reserved.

Microbial adaptation to biodegrade toxic organic micro-pollutants in membrane bioreactor using different sludge sources.

PubMed

Boonnorat, Jarungwit; Chiemchaisri, Chart; Chiemchaisri, Wilai; Yamamoto, Kazuo

2014-08-01

Biodegradation of toxic organic micro-pollutants in municipal solid waste (MSW) leachate by membrane bioreactor (MBR) was investigated. The MBR systems were seeded with different sludge sources, one was from a pilot-scale MBR system treating MSW leachate and the other was from an activated sludge sewage treatment plant. The biodegradation of BPA, 2,6-DTBP, BHT, DEP, DBP and DEHP, DCP and BBzP, by sludge from both reactors were found improved with time. However, enhanced biodegradation of micro-pollutants was observed in MBR operated under long sludge age condition. Bacterial population analyses determined by PCR-DGGE revealed the development of phenol and phthalate degrading bacteria consortium in MBR sludge during its operation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Biodegradation of potato slops from a rural distillery by thermophilic aerobic bacteria.

PubMed

Cibis, Edmund; Kent, Christopher A; Krzywonos, Malgorzata; Garncarek, Zbigniew; Garncarek, Barbara; Miśkiewicz, Tadeusz

2002-10-01

A study has been made of thermophilic aerobic biodegradation of the liquid fraction of potato slops (distillation residue) from a rural distillery. The COD of this fraction ranged from 49 to 104 g O2/l, the main contributions to the COD coming from organic acids, reducing substances, and glycerol. It was found that biodegradation could be divided into the following stages: organic acids were removed first, followed by reducing substances and glycerol. The extent of removal varied according to the process temperature. At 50 degrees C, acetic and malic acids were removed completely, but the amount of isobutyric acid increased. At 60 degrees C, organic acid removal ranged from 51.2% (isobutyric acid) to 99.6% (lactic acid). Removals of glycerol and reducing substances were 86.2% and 87.4%, respectively. COD reduction was also temperature dependent, the highest removal efficiency (76.7%) being achieved at 60 degrees C. Dissolved oxygen may have limited the biodegradation process, as indicated by the DOT-versus-time profile.

Osmotic versus conventional membrane bioreactors integrated with reverse osmosis for water reuse: Biological stability, membrane fouling, and contaminant removal.

PubMed

Luo, Wenhai; Phan, Hop V; Xie, Ming; Hai, Faisal I; Price, William E; Elimelech, Menachem; Nghiem, Long D

2017-02-01

This study systematically compares the performance of osmotic membrane bioreactor - reverse osmosis (OMBR-RO) and conventional membrane bioreactor - reverse osmosis (MBR-RO) for advanced wastewater treatment and water reuse. Both systems achieved effective removal of bulk organic matter and nutrients, and almost complete removal of all 31 trace organic contaminants investigated. They both could produce high quality water suitable for recycling applications. During OMBR-RO operation, salinity build-up in the bioreactor reduced the water flux and negatively impacted the system biological treatment by altering biomass characteristics and microbial community structure. In addition, the elevated salinity also increased soluble microbial products and extracellular polymeric substances in the mixed liquor, which induced fouling of the forward osmosis (FO) membrane. Nevertheless, microbial analysis indicated that salinity stress resulted in the development of halotolerant bacteria, consequently sustaining biodegradation in the OMBR system. By contrast, biological performance was relatively stable throughout conventional MBR-RO operation. Compared to conventional MBR-RO, the FO process effectively prevented foulants from permeating into the draw solution, thereby significantly reducing fouling of the downstream RO membrane in OMBR-RO operation. Accumulation of organic matter, including humic- and protein-like substances, as well as inorganic salts in the MBR effluent resulted in severe RO membrane fouling in conventional MBR-RO operation. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

Changes in the dissolved organic matter leaching from soil under severe temperature and N-deposition.

PubMed

Nguyen, Hang Vo-Minh; Choi, Jung Hyun

2015-06-01

In this study, we conducted growth chamber experiments using three types of soil (wetland, rice paddy, and forest) under the conditions of a severe increase in the temperature and N-deposition in order to investigate how extreme weather influences the characteristics of the dissolved organic matter (DOM) leaching from different soil types. This leachate controls the quantity and quality of DOM in surface water systems. After 5 months of incubation, the dissolved organic carbon (DOC) concentrations decreased in the range of 21.1 to 88.9 %, while the specific UV absorption (SUVA) values increased substantially in the range of 19.9 to 319.9 % for all of the samples. Higher increases in the SUVA values were observed at higher temperatures, whereas the opposite trend was observed for samples with N-addition. The parallel factor analysis (PARAFAC) results showed that four fluorescence components: terrestrial humic-like (component 1 (C1)), microbial humic-like (component 2 (C2)), protein-like (component 3 (C3)), and anthropogenic humic-like (component 4 (C4)) constituted the fluorescence matrices of soil samples. During the experiment, labile DOM from the soils was consumed and transformed into resistant aromatic carbon structures and less biodegradable components via microbial processes. The principle component analysis (PCA) results indicated that severe temperatures and N-deposition could enhance the contribution of the aromatic carbon compounds and humic-like components in the soil samples.

Biodegradation of organic pollutants in saline wastewater by halophilic microorganisms: a review.

PubMed

Castillo-Carvajal, Laura C; Sanz-Martín, José Luis; Barragán-Huerta, Blanca E

2014-01-01

Agro-food, petroleum, textile, and leather industries generate saline wastewater with a high content of organic pollutants such as aromatic hydrocarbons, phenols, nitroaromatics, and azo dyes. Halophilic microorganisms are of increasing interest in industrial waste treatment, due to their ability to degrade hazardous substances efficiently under high salt conditions. However, their full potential remains unexplored. The isolation and identification of halophilic and halotolerant microorganisms from geographically unrelated and geologically diverse hypersaline sites supports their application in bioremediation processes. Past investigations in this field have mainly focused on the elimination of polycyclic aromatic hydrocarbons and phenols, whereas few studies have investigated N-aromatic compounds, such as nitro-substituted compounds, amines, and azo dyes, in saline wastewater. Information regarding the growth conditions and degradation mechanisms of halophilic microorganisms is also limited. In this review, we discuss recent research on the removal of organic pollutants such as organic matter, in terms of chemical oxygen demand (COD), dyes, hydrocarbons, N-aliphatic and N-aromatic compounds, and phenols, in conditions of high salinity. In addition, some proposal pathways for the degradation of aromatic compounds are presented.

Reduced temperature hydrolysis at 134 °C before thermophilic anaerobic digestion of waste activated sludge at increasing organic load.

PubMed

Gianico, A; Braguglia, C M; Cesarini, R; Mininni, G

2013-09-01

The performance of thermophilic digestion of waste activated sludge, either untreated or thermal pretreated, was evaluated through semi-continuous tests carried out at organic loading rates in the range of 1-3.7 kg VS/m(3)d. Although the thermal pretreatment at T=134 °C proved to be effective in solubilizing organic matter, no significant gain in organics degradation was observed. However, the digestion of pretreated sludge showed significant soluble COD removal (more than 55%) whereas no removal occurred in control reactors. The lower the initial sludge biodegradability, the higher the efficiency of thermal pretreated digestion was observed, in particular as regards higher biogas and methane production rates with respect to the parallel untreated sludge digestion. Heat balance of the combined thermal hydrolysis/thermophilic digestion process, applied on full-scale scenarios, showed positive values for direct combustion of methane. In case of combined heat and power generation, attractive electric energy recoveries were obtained, with a positive heat balance at high load. Copyright © 2013. Published by Elsevier Ltd.

Biodegradable Polymers

PubMed Central

Vroman, Isabelle; Tighzert, Lan

2009-01-01

Biodegradable materials are used in packaging, agriculture, medicine and other areas. In recent years there has been an increase in interest in biodegradable polymers. Two classes of biodegradable polymers can be distinguished: synthetic or natural polymers. There are polymers produced from feedstocks derived either from petroleum resources (non renewable resources) or from biological resources (renewable resources). In general natural polymers offer fewer advantages than synthetic polymers. The following review presents an overview of the different biodegradable polymers that are currently being used and their properties, as well as new developments in their synthesis and applications.

Biodegradation and bio-sorption of antibiotics and non-steroidal anti-inflammatory drugs using immobilized cell process.

PubMed

Yu, Tsung-Hsien; Lin, Angela Yu-Chen; Panchangam, Sri Chandana; Hong, Pui-Kwan Andy; Yang, Ping-Yi; Lin, Cheng-Fang

2011-08-01

In the present study, the removal mechanisms of four antibiotics (sulfamethoxazole, sulfadimethoxine, sulfamethazine, and trimethoprim) and four non-steroidal anti-inflammatory drugs (acetaminophen, ibuprofen, ketoprofen, and naproxen) in immobilized cell process were investigated using batch reactors. This work principally explores the individual or collective roles of biodegradation and bio-sorption as removal routes of the target pharmaceuticals and the results were validated by various experimental and analytical tools. Biodegradation and bio-sorption were found as dominant mechanisms for the drug removal, while volatilization and hydrolysis were negligible for all target pharmaceuticals. The target pharmaceuticals responded to the two observed removal mechanisms in different ways, typically: (1) strong biodegradability and bio-sorption by acetaminophen, (2) strong biodegradability and weak bio-sorption by sulfamethoxazole, sulfadimethoxine, ibuprofen and naproxen, (3) low biodegradability and weak bio-sorption by sulfamethazine and ketoprofen, and (4) low biodegradability and medium bio-sorption by trimethoprim. In the sorption/desorption experiment, acetaminophen, sulfamethoxazole and sulfadimethoxine were characterized by strong sorption and weak desorption. A phenomenon of moderate sorption and well desorption was observed for sulfamethazine, trimethoprim and naproxen. Both ibuprofen and ketoprofen were weakly sorbed and strongly desorbed. Copyright © 2011 Elsevier Ltd. All rights reserved.

Degradation of Nitroguanidine in Soils

DTIC Science & Technology

1985-01-01

columns. Nitroguanidine was biodegraded if sufficient supplemental carbon was provided in the wastewater. The primary product formed during the... biodegradation of nitroguanidine in soil was ammonia. Only trace concentration of nitrosoguanidine were detected and no significant levels of other organic...low cost treatment option for these wastewaters. In addition, preliminary work was performed to evaluate the biodegradability of guanidine nitrate

Use of the University of Minnesota Biocatalysis/Biodegradation Database for study of microbial degradation

PubMed Central

2012-01-01

Microorganisms are ubiquitous on earth and have diverse metabolic transformative capabilities important for environmental biodegradation of chemicals that helps maintain ecosystem and human health. Microbial biodegradative metabolism is the main focus of the University of Minnesota Biocatalysis/Biodegradation Database (UM-BBD). UM-BBD data has also been used to develop a computational metabolic pathway prediction system that can be applied to chemicals for which biodegradation data is currently lacking. The UM-Pathway Prediction System (UM-PPS) relies on metabolic rules that are based on organic functional groups and predicts plausible biodegradative metabolism. The predictions are useful to environmental chemists that look for metabolic intermediates, for regulators looking for potential toxic products, for microbiologists seeking to understand microbial biodegradation, and others with a wide-range of interests. PMID:22587916

The effects of organic matter-mineral interactions and organic matter chemistry on diuron sorption across a diverse range of soils.

PubMed

Smernik, Ronald J; Kookana, Rai S

2015-01-01

Sorption of non-ionic organic compounds to soil is usually expressed as the carbon-normalized partition coefficient (KOC), because it is assumed that the main factor that influences the amount sorbed is the organic carbon content of the soil. However, KOC can vary by a factor of at least ten across a range of soils. We investigated two potential causes of variation in diuron KOC - organic matter-mineral interactions and organic matter chemistry - for a diverse set of 34 soils from Sri Lanka, representing a wide range of soil types. Treatment with hydrofluoric acid (HF-treatment) was used to concentrate soil organic matter. HF-treatment increased KOC for the majority of soils (average factor 2.4). We attribute this increase to the blocking of organic matter sorption sites in the whole soils by minerals. There was no significant correlation between KOC for the whole soils and KOC for the HF-treated soils, indicating that the importance of organic matter-mineral interactions varied greatly amongst these soils. There was as much variation in KOC across the HF-treated soils as there was across the whole soils, indicating that the nature of soil organic matter is also an important contributor to KOC variability. Organic matter chemistry, determined by solid-state (13)C nuclear magnetic resonance (NMR) spectroscopy, was correlated with KOC for the HF-treated soils. In particular, KOC increased with the aromatic C content (R=0.64, p=1×10(-6)), and decreased with O-alkyl C (R=-0.32, p=0.03) and alkyl C (R=-0.41, p=0.004) content. Copyright © 2014 Elsevier Ltd. All rights reserved.

Correlations between PAH bioavailability, degrading bacteria, and soil characteristics during PAH biodegradation in five diffusely contaminated dissimilar soils.

PubMed

Crampon, M; Bureau, F; Akpa-Vinceslas, M; Bodilis, J; Machour, N; Le Derf, F; Portet-Koltalo, F

2014-01-01

The natural biodegradation of seven polycyclic aromatic hydrocarbons (PAHs) by native microorganisms was studied in five soils from Normandy (France) from diffusely polluted areas, which can also pose a problem in terms of surfaces and amounts of contaminated soils. Bioavailability tests using cyclodextrin-based extractions were performed. The natural degradation of low molecular weight (LMW) PAHs was not strongly correlated to their bioavailability due to their sorption to geosorbents. Conversely, the very low degradation of high molecular weight (HMW) PAHs was partly correlated to their poor availability, due to their sorption on complexes of organic matter and kaolinites or smectites. A principal component analysis allowed us to distinguish between the respective degradation behaviors of LMW and HMW PAHs. LMW PAHs were degraded in less than 2-3 months and were strongly influenced by the relative percentage of phenanthrene-degrading bacteria over total bacteria in soils. HMW PAHs were not significantly degraded, not only because they were less bioavailable but also because of a lack of degrading microorganisms. Benzo[a]pyrene stood apart since it was partly degraded in acidic soils, probably because of a catabolic cooperation between bacteria and fungi.

Plant-Associated Bacterial Degradation of Toxic Organic Compounds in Soil

PubMed Central

McGuinness, Martina; Dowling, David

2009-01-01

A number of toxic synthetic organic compounds can contaminate environmental soil through either local (e.g., industrial) or diffuse (e.g., agricultural) contamination. Increased levels of these toxic organic compounds in the environment have been associated with human health risks including cancer. Plant-associated bacteria, such as endophytic bacteria (non-pathogenic bacteria that occur naturally in plants) and rhizospheric bacteria (bacteria that live on and near the roots of plants), have been shown to contribute to biodegradation of toxic organic compounds in contaminated soil and could have potential for improving phytoremediation. Endophytic and rhizospheric bacterial degradation of toxic organic compounds (either naturally occurring or genetically enhanced) in contaminated soil in the environment could have positive implications for human health worldwide and is the subject of this review. PMID:19742157

Hydrogen Isotopes in Amino Acids and Soils Offer New Potential to Study Complex Processes

NASA Astrophysics Data System (ADS)

Fogel, M. L.; Newsome, S. D.; Williams, E. K.; Bradley, C. J.; Griffin, P.; Nakamoto, B. J.

2016-12-01

Hydrogen isotopes have been analyzed extensively in the earth and biogeosciences to trace water through various environmental systems. The majority of the measurements have been made on water in rocks and minerals (inorganic) or non-exchangeable H in lipids (organic), important biomarkers that represent a small fraction of the organic molecules synthesized by living organisms. Our lab has been investigating hydrogen isotopes in amino acids and complex soil organic matter, which have traditionally been thought to be too complex to interpret owing to complications from potentially exchangeable hydrogen. For the amino acids, we show how hydrogen in amino acids originates from two sources, food and water, and demonstrate that hydrogen isotopes can be routed directly between organisms. Amino acid hydrogen isotopes may unravel cycling in extremophiles in order to discover novel biochemical pathways central to the organism. For soil organic matter, recent approaches to understanding the origin of soil organic matter are pointing towards root exudates along with microbial biomass as the source, rather than aboveground leaf litter. Having an isotope tracer in very complex, potentially exchangeable organic matter can be handled with careful experimentation. Although no new instrumentation is being used per se, extension of classes of organic matter to isotope measurements has potential to open up new doors for understanding organic matter cycling on earth and in planetary materials.

Characterizing The Microbial Lability And Isotopic (14C, 13C) Signatures Of Marine Organic Matter With A Novel Culture Vessel System

NASA Astrophysics Data System (ADS)

Beaupre, S. R.; Mahmoudi, N.; Pearson, A.

2016-02-01

The rate at which non-living organic matter is respired in the ocean is an unconstrained and important property of the marine carbon cycle. Studies of inherent mineralization rates are complicated by the fact that marine organic matter is a mixture of compounds that vary in reactivity and concentration. While natural radiocarbon ages (14C, half-life = 5730 yr) have served as proxies for lability, they have not been used extensively to characterize that fraction of marine organic matter that is biologically accessible. To address this problem, we developed a novel batch culture system to monitor the time-dependent production rates and isotopic signatures of CO2 released during microbial degradation of natural organic matter. The system simulated a nepheloid layer by maintaining a slurry of decarbonated sediment and minimal media (M9) in a custom 2-liter culture vessel. The natural microbial community was allowed to develop within the sediment, and respired CO2 was continuously sparged from the medium with helium and oxygen, quantified in real time with an infrared gas analyzer, and isolated as a series of contiguous fractions for subsequent isotopic (∆14C, d13C) characterization. Control experiments indicated the accumulation of just 4.5 mg of background carbon per hour of continuous gas flow, which constituted ≤ 10 % of the respired carbon mass in each fraction. Since ∆14C values are conserved during molecular transformations, this low-blank system enables the detection of subtle shifts in the "age" of organic matter respired during the course of a culture experiment. Analyses of sediments from Falmouth, MA revealed both a variable CO2 production rate and an increase in post-bomb ∆14C values during a 10-day incubation. This suggests that the microbial lability of organic matter at this site decreased non-linearly with apparent 14C age, and that the least labile fraction observed was not more than 50 years old. These results underscore the complex relationship between microbial communities, organic matter composition, and its 14C age distribution.

Microbial colonization and degradation of polyethylene and biodegradable plastic bags in temperate fine-grained organic-rich marine sediments.

PubMed

Nauendorf, Alice; Krause, Stefan; Bigalke, Nikolaus K; Gorb, Elena V; Gorb, Stanislav N; Haeckel, Matthias; Wahl, Martin; Treude, Tina

2016-02-15

To date, the longevity of plastic litter at the sea floor is poorly constrained. The present study compares colonization and biodegradation of plastic bags by aerobic and anaerobic benthic microbes in temperate fine-grained organic-rich marine sediments. Samples of polyethylene and biodegradable plastic carrier bags were incubated in natural oxic and anoxic sediments from Eckernförde Bay (Western Baltic Sea) for 98 days. Analyses included (1) microbial colonization rates on the bags, (2) examination of the surface structure, wettability, and chemistry, and (3) mass loss of the samples during incubation. On average, biodegradable plastic bags were colonized five times higher by aerobic and eight times higher by anaerobic microbes than polyethylene bags. Both types of bags showed no sign of biodegradation during this study. Therefore, marine sediment in temperate coastal zones may represent a long-term sink for plastic litter and also supposedly compostable material. Copyright © 2016 Elsevier Ltd. All rights reserved.

Influence of humic acid addition on the degradation of pharmaceuticals by biofilms in effluent wastewater.

PubMed

Tang, Kai; Escola Casas, Monica; Ooi, Gordon T H; Kaarsholm, Kamilla M S; Bester, Kai; Andersen, Henrik R

2017-05-01

The degradation of organic micropollutants in wastewater treatment is suspected to depend on co-degradation i.e. be dependent on concentrations of substrate. This complicates predicting and modelling their fate. The effect of humic acid, as a model for complex organic substrate, was investigated in relation to the biodegradation of pharmaceuticals by suspended biofilm carriers adapted to polishing effluent water from a tertiary sewage treatment plant. Twelve out of 22 investigated pharmaceuticals were significantly biodegradable. The biodegradation rate constants of ten of those compounds were increasing with increased humic acid concentrations. At the highest humic acid concentration (30mgC/L), the biodegradation rate constants were four times higher than the biodegradation rate constants without added humic acid. This shows that the presence of complex substrate stimulates degradation via a co-metabolism-like mechanism and competitive inhibition does not occur. Increases of rate constant per mgC/L are tentatively calculated. Copyright © 2017 Elsevier GmbH. All rights reserved.

Biodegradability enhancement and detoxification of cork processing wastewater molecular size fractions by ozone.

PubMed

Santos, Diana C; Silva, Lúcia; Albuquerque, António; Simões, Rogério; Gomes, Arlindo C

2013-11-01

Cork boiling wastewater pollutants were fractionated by sequential use of four ultrafiltration membranes and five fractions were obtained: four retentates (>100, 50-100, 20-50 and 10-20 kDa) and one permeate (<10 kDa); which were used to study the correlation of molecular size with biodegradability and toxicity before and after ozonation. The results show that molecular size is correlated with organic load and restrains biodegradability. The fraction with >100 kDa corresponds to 56% of the organic load and the one with <10 kDa only 8%. The biodegradability of fractions increased 182% with fractions molecular size reduction from >100 to <10 kDa and the chemical oxygen demand (COD) was from 3436 to 386 mg L(-1). For biodegradability enhancement the best outcome of ozonation was obtained with compounds having molecular size >20 kDa and range from 5% up to 175% for applied ozone doses to COD ratios between 0.15 and 0.38. Copyright © 2013 Elsevier Ltd. All rights reserved.

Biodegradation of PAHs and PCBs in soils and sludges

USGS Publications Warehouse

Liu, L.; Tindall, J.A.; Friedel, M.J.

2007-01-01

Results from a multi-year, pilot-scale land treatment project for PAHs and PCBs biodegradation were evaluated. A mathematical model, capable of describing sorption, sequestration, and biodegradation in soil/water systems, is applied to interpret the efficacy of a sequential active-passive biotreatment process of organic chemicals on remediation sites. To account for the recalcitrance of PAHs and PCBs in soils and sludges during long-term biotreatment, this model comprises a kinetic equation for organic chemical intraparticle sequestration process. Model responses were verified by comparison to measurements of biodegradation of PAHs and PCBs in land treatment units; a favorable match was found between them. Model simulations were performed to predict on-going biodegradation behavior of PAHs and PCBs in land treatment units. Simulation results indicate that complete biostabilization will be achieved when the concentration of reversibly sorbed chemical (S RA) reduces to undetectable levels, with a certain amount of irreversibly sequestrated residual chemical (S IA) remaining within the soil particle solid phase. The residual fraction (S IA) tends to lose its original chemical and biological activity, and hence, is much less available, toxic, and mobile than the "free" compounds. Therefore, little or no PAHs and PCBs will leach from the treatment site and constitutes no threat to human health or the environment. Biotreatment of PAHs and PCBs can be terminated accordingly. Results from the pilot-scale testing data and model calculations also suggest that a significant fraction (10-30%) of high-molecular-weight PAHs and PCBs could be sequestrated and become unavailable for biodegradation. Bioavailability (large K d , i.e., slow desorption rate) is the key factor limiting the PAHs degradation. However, both bioavailability and bioactivity (K in Monod kinetics, i.e., number of microbes, nutrients, and electron acceptor, etc.) regulate PCBs biodegradation. The sequential active-passive biotreatment can be a cost-effective approach for remediation of highly hydrophobic organic contaminants. The mathematical model proposed here would be useful in the design and operation of such organic chemical biodegradation processes on remediation sites. ?? 2007 Springer Science+Business Media B.V.

Non-invasive localization of organic matter in soil aggregates using SR-μCT

NASA Astrophysics Data System (ADS)

Peth, Stephan; Mordhorst, Anneka; Chenu, Claire; Uteau Puschmann, Daniel; Garnier, Patricia; Nunan, Naoise; Pot, Valerie; Beckmann, Felix; Ogurreck, Malte

2014-05-01

Knowledge of the location of soil organic matter (SOM) and its spatial association to soil structure is an important step in improving modeling approaches for simulating organic matter turnover processes. Advanced models for carbon mineralization are able to account for the 3D distribution of SOM which is assumed to influence mineralisation. However, their application is still limited by the fact that no method exists to non-invasively determine the 3D spatial distribution of SOM in structured soils. SR-based X-ray microtomography (SR-µCT) is an advanced and promising tool in gaining knowledge on the 3-dimensional organization of soil phases (minerals, organic matter, water, air) which on a voxel level could be implemented into spatially explicit models. However, since the contrast of linear attenuation coefficients of soil organic matter on the one hand and mineral components and water on the other hand are relatively low, especially when materials are finely dispersed, organic matter within the soil pore space is often not resolved in ordinary X-ray absorption contrast imaging. To circumvent this problem we have developed a staining procedure for organic matter using Osmium-tetroxide since Osmium is an element with an absorption edge at a higher X-ray energy level. Osmium is known from transmission electron microscopy analysis (TEM) to stain organic matter specifically and irreversibly while having an absorption edge at approximately 74 keV. We report on the application of a novel Osmium vapor staining method to analyze differences in organic matter content and identify small scale spatial distribution of SOM in soil aggregates. To achieve this we have taken soil aggregate samples (6-8 mm across) obtained from arable soils differing in soil management. Aggregate samples were investigated by synchrotron-based X-ray microtomography (SR-µCT) after staining the sample with Osmium-tetroxide (OsO4) vapor. We utilized the monochromatic X-ray beam to locate osmium bound to SOM in the stained soil aggregate samples by scanning the aggregates at different photon energies: 30 keV at which the attenuation contrast is optimal for distinguishing other soil constituents, 70 keV (below the absorption of osmium) and 78 keV (above the absorption edge of osmium). The results suggest that particulate organic matter, which was not visibly by scanning samples at energy levels optimal for resolving soil structure (30 keV), was identified after osmium staining and scanning the samples at energy levels just below (70 keV) and above (78 keV) the absorption edge of Osmium. Subtracting the images below from the images above the osmium edged we were able to isolate stained particulate organic matter which otherwise would have been wrongly interpreted as pore space without staining. Combining both pore space and organic matter distribution we are able to investigate the association of SOM with soil structure.

Microbial community in a full-scale drinking water biosand filter.

PubMed

Feng, Shuo; Chen, Chao; Wang, Qingfeng; Yang, Zhiyu; Zhang, Xiaojian; Xie, Shuguang

2013-04-01

To remove turbidity and minimize microbiological risks, rapid sand filtration is one of main drinking water treatment processes in the world. However, after a long-term operation, sand particles will be colonized by microorganisms which can remove biodegradable organic matters and nitrogen compounds. In this study, 16S rRNA gene clone library analysis was applied to characterize the microbial community in a full-scale biosand filter used for drinking water treatment. The results indicate that phylum Nitrospirae and class Alphaproteobacteria were the dominant bacterial groups in the biosand sample collected from the upper filter layer. The dominance of Sphingomonas species might pose a microbiological risk. This work could provide some new insights into microbial community in drinking water biofilter.

Influence of Concentration and Salinity on the Biodegradability of Organic Additives in Hydraulic Fracturing Fluid

NASA Astrophysics Data System (ADS)

Mouser, P. J.; Kekacs, D.

2014-12-01

One of the risks associated with the use of hydraulic fracturing technologies for energy development is the potential release of hydraulic fracturing-related fluids into surface waters or shallow aquifers. Many of the organic additives used in hydraulic fracturing fluids are individually biodegradable, but little is know on how they will attenuate within a complex organic fluid in the natural environment. We developed a synthetic hydraulic fracturing fluid based on disclosed recipes used by Marcellus shale operators to evaluate the biodegradation potential of organic additives across a concentration (25 to 200 mg/L DOC) and salinity gradient (0 to 60 g/L) similar to Marcellus shale injected fluids. In aerobic aqueous solutions, microorganisms removed 91% of bulk DOC from low SFF solutions and 57% DOC in solutions having field-used SFF concentrations within 7 days. Under high SFF concentrations, salinity in excess of 20 g/L inhibited organic compound biodegradation for several weeks, after which time the majority (57% to 75%) of DOC remained in solution. After SFF amendment, the initially biodiverse lake or sludge microbial communities were quickly dominated (>79%) by Pseudomonas spp. Approximately 20% of added carbon was converted to biomass while the remainder was respired to CO2 or other metabolites. Two alcohols, isopropanol and octanol, together accounted for 2-4% of the initial DOC, with both compounds decreasing to below detection limits within 7 days. Alcohol degradation was associated with an increase in acetone at mg/L concentrations. These data help to constrain the biodegradation potential of organic additives in hydraulic fracturing fluids and guide our understanding of the microbial communities that may contribute to attenuation in surface waters.

Fractionation and characterization of organic matter in wastewater from a swine waste-retention basin

USGS Publications Warehouse

Leenheer, Jerry A.; Rostad, Colleen E.

2004-01-01

Organic matter in wastewater sampled from a swine waste-retention basin in Iowa was fractionated into 14 fractions on the basis of size (particulate, colloid, and dissolved); volatility; polarity (hydrophobic, transphilic, hydrophilic); acid, base, neutral characteristics; and precipitate or flocculates (floc) formation upon acidification. The compound-class composition of each of these fractions was determined by infrared and 13C-NMR spectral analyses. Volatile acids were the largest fraction with acetic acid being the major component of this fraction. The second most abundant fraction was fine particulate organic matter that consisted of bacterial cells that were subfractionated into extractable lipids consisting of straight chain fatty acids, peptidoglycans components of bacterial cell walls, and protein globulin components of cellular plasma. The large lipid content of the particulate fraction indicates that non-polar contaminants, such as certain pharmaceuticals added to swine feed, likely associate with the particulate fraction through partitioning interactions. Hydrocinnamic acid is a major component of the hydrophobic acid fraction, and its presence is an indication of anaerobic degradation of lignin originally present in swine feed. This is the first study to combine particulate organic matter with dissolved organic matter fractionation into a total organic matter fractionation and characterization.

Hailstones: a window into the microbial and chemical inventory of a storm cloud.

PubMed

Šantl-Temkiv, Tina; Finster, Kai; Dittmar, Thorsten; Hansen, Bjarne Munk; Thyrhaug, Runar; Nielsen, Niels Woetmann; Karlson, Ulrich Gosewinkel

2013-01-01

Storm clouds frequently form in the summer period in temperate climate zones. Studies on these inaccessible and short-lived atmospheric habitats have been scarce. We report here on the first comprehensive biogeochemical investigation of a storm cloud using hailstones as a natural stochastic sampling tool. A detailed molecular analysis of the dissolved organic matter in individual hailstones via ultra-high resolution mass spectrometry revealed the molecular formulae of almost 3000 different compounds. Only a small fraction of these compounds were rapidly biodegradable carbohydrates and lipids, suitable for microbial consumption during the lifetime of cloud droplets. However, as the cloud environment was characterized by a low bacterial density (Me = 1973 cells/ml) as well as high concentrations of both dissolved organic carbon (Me = 179 µM) and total dissolved nitrogen (Me = 30 µM), already trace amounts of easily degradable organic compounds suffice to support bacterial growth. The molecular fingerprints revealed a mainly soil origin of dissolved organic matter and a minor contribution of plant-surface compounds. In contrast, both the total and the cultivable bacterial community were skewed by bacterial groups (γ-Proteobacteria, Sphingobacteriales and Methylobacterium) that indicated the dominance of plant-surface bacteria. The enrichment of plant-associated bacterial groups points at a selection process of microbial genera in the course of cloud formation, which could affect the long-distance transport and spatial distribution of bacteria on Earth. Based on our results we hypothesize that plant-associated bacteria were more likely than soil bacteria (i) to survive the airborne state due to adaptations to life in the phyllosphere, which in many respects matches the demands encountered in the atmosphere and (ii) to grow on the suitable fraction of dissolved organic matter in clouds due to their ecological strategy. We conclude that storm clouds are among the most extreme habitats on Earth, where microbial life exists.

Hailstones: A Window into the Microbial and Chemical Inventory of a Storm Cloud

PubMed Central

Šantl-Temkiv, Tina; Finster, Kai; Dittmar, Thorsten; Hansen, Bjarne Munk; Nielsen, Niels Woetmann; Karlson, Ulrich Gosewinkel

2013-01-01

Storm clouds frequently form in the summer period in temperate climate zones. Studies on these inaccessible and short-lived atmospheric habitats have been scarce. We report here on the first comprehensive biogeochemical investigation of a storm cloud using hailstones as a natural stochastic sampling tool. A detailed molecular analysis of the dissolved organic matter in individual hailstones via ultra-high resolution mass spectrometry revealed the molecular formulae of almost 3000 different compounds. Only a small fraction of these compounds were rapidly biodegradable carbohydrates and lipids, suitable for microbial consumption during the lifetime of cloud droplets. However, as the cloud environment was characterized by a low bacterial density (Me = 1973 cells/ml) as well as high concentrations of both dissolved organic carbon (Me = 179 µM) and total dissolved nitrogen (Me = 30 µM), already trace amounts of easily degradable organic compounds suffice to support bacterial growth. The molecular fingerprints revealed a mainly soil origin of dissolved organic matter and a minor contribution of plant-surface compounds. In contrast, both the total and the cultivable bacterial community were skewed by bacterial groups (γ-Proteobacteria, Sphingobacteriales and Methylobacterium) that indicated the dominance of plant-surface bacteria. The enrichment of plant-associated bacterial groups points at a selection process of microbial genera in the course of cloud formation, which could affect the long-distance transport and spatial distribution of bacteria on Earth. Based on our results we hypothesize that plant-associated bacteria were more likely than soil bacteria (i) to survive the airborne state due to adaptations to life in the phyllosphere, which in many respects matches the demands encountered in the atmosphere and (ii) to grow on the suitable fraction of dissolved organic matter in clouds due to their ecological strategy. We conclude that storm clouds are among the most extreme habitats on Earth, where microbial life exists. PMID:23372660

Reuse of polyethylene waste in road construction.

PubMed

Raju, S S S V Gopala; Murali, M; Rengaraju, V R

2007-01-01

The cost of construction of flexible pavements depends on thickness of the pavement layers. The thickness of pavement mainly depends on the strength of the subgrade. By suitable improvement to the strength of the subgrade, considerable saving in the scarce resources and economy can be achieved. Because of their lightweight, easy handling, non-breakable and corrosion free nature, polyethylene have surpassed all other materials in utility. But polyethylene waste has been a matter of concern to environmentalists as it is non-biodegradable. In this investigation, an attempt has been made to study the improvement of California Bearing Ratio (CBR) value of soils stabilized with waste polyethylene bags. This alternative material is mixed in different proportions to the gravel and clay to determine the improvement ofCBR value. Use of the waste polyethylene bags observed to have a significant impact on the strength and economy in pavement construction, when these are available locally in large quantities.

Biodegradable and Petroleum-Based Microplastics Do Not Differ in Their Ingestion and Excretion but in Their Biological Effects in a Freshwater Invertebrate Gammarus fossarum

PubMed Central

Straub, Sandrine; Hirsch, Philipp E.; Burkhardt-Holm, Patricia

2017-01-01

Research on the uptake and effects of bioplastics by aquatic organisms is still in its infancy. Here, we aim to advance the field by comparing uptake and effects of microplastic particles (MPP) of a biodegradable bioMPP (polyhydroxybutyrate (PHB)) and petroleum-based MPP (polymethylmethacrylate (PMMA)) in the freshwater amphipod Gammarus fossarum. Ingestion of both MPP in different particle sizes (32–250 µm) occurred after 24 h, with highest ingestion of particles in the range 32–63 µm and almost complete egestion after 64 h. A four-week effect-experiment showed a significant decrease of the assimilation efficiency in amphipods exposed to the petroleum-based MPP from week two onwards. The petroleum-based PMMA affected assimilation efficiency significantly in contrast to the biodegradable PHB, but overall differences in direct comparison of MPP types were small. Both MPP types led to a significantly lower wet weight gain relative to the control treatments. After four weeks, differences between both MPP types and silica, used as a natural particle control, were detected. In summary, these results suggest that both MPP types provoke digestive constraints on the amphipods, which go beyond those of natural non-palatable particles. This highlights the need for more detailed research comparing environmental effects of biodegradable and petroleum-based MPP and testing those against naturally occurring particle loads. PMID:28703776

Here today, gone tomorrow: biodegradable soft robots

NASA Astrophysics Data System (ADS)

Rossiter, Jonathan; Winfield, Jonathan; Ieropoulos, Ioannis

2016-04-01

One of the greatest challenges to modern technologies is what to do with them when they go irreparably wrong or come to the end of their productive lives. The convention, since the development of modern civilisation, is to discard a broken item and then procure a new one. In the 20th century enlightened environmentalists campaigned for recycling and reuse (R and R). R and R has continued to be an important part of new technology development, but there is still a huge problem of non-recyclable materials being dumped into landfill and being discarded in the environment. The challenge is even greater for robotics, a field which will impact on all aspects of our lives, where discards include motors, rigid elements and toxic power supplies and batteries. One novel solution is the biodegradable robot, an active physical machine that is composed of biodegradable materials and which degrades to nothing when released into the environment. In this paper we examine the potential and realities of biodegradable robotics, consider novel solutions to core components such as sensors, actuators and energy scavenging, and give examples of biodegradable robotics fabricated from everyday, and not so common, biodegradable electroactive materials. The realisation of truly biodegradable robots also brings entirely new deployment, exploration and bio-remediation capabilities: why track and recover a few large non-biodegradable robots when you could speculatively release millions of biodegradable robots instead? We will consider some of these exciting developments and explore the future of this new field.

Biodegradation of persistent organics can overcome adsorption-desorption hysteresis in biological activated carbon systems.

PubMed

Abromaitis, V; Racys, V; van der Marel, P; Meulepas, R J W

2016-04-01

In Biological Activated Carbon (BAC) systems, persistent organic pollutants can be removed through a combination of adsorption, desorption and biodegradation. These processes might be affected by the presence of other organics, especially by the more abundant easily-biodegradable organics, like acetate. In this research these relations are quantified for the removal of the persistent pharmaceutical metoprolol. Acetate did not affect the adsorption and desorption of metoprolol, but it did greatly enhance the metoprolol biodegradation. At least part of the BAC biomass growing on acetate was also able to metabolise metoprolol, although metoprolol was only converted after the acetate was depleted. The presence of easily-degradable organics like acetate in the feeding water is therefore beneficial for the removal of metoprolol in BAC systems. The isotherms obtained from metoprolol adsorption and desorption experiments showed that BAC systems are subject to hysteresis; for AC bioregeneration to take place the microbial biomass has to reduce the concentration at the AC-biomass interface 2.7 times compared to the concentration at which the carbon was being loaded. However, given the threshold concentration of the MET degrading microorganisms (<0.08 μg/L) versus the average influent concentration (1.3 μg/L), bioregeneration is feasible. Copyright © 2016 Elsevier Ltd. All rights reserved.

High-performance green flexible electronics based on biodegradable cellulose nanofibril paper

Treesearch

Yei Hwan Jung; Tzu-Hsuan Chang; Huilong Zhang; Chunhua Yao; Qifeng Zheng; Vina W. Yang; Hongyi Mi; Munho Kim; Sang June Cho; Dong-Wook Park; Hao Jiang; Juhwan Lee; Yijie Qiu; Weidong Zhou; Zhiyong Cai; Shaoqin Gong; Zhenqiang Ma

2015-01-01

Today’s consumer electronics, such as cell phones, tablets and other portable electronic devices, are typically made of non-renewable, non-biodegradable, and sometimes potentially toxic (for example, gallium arsenide) materials. These consumer electronics are frequently upgraded or discarded, leading to serious environmental contamination. Thus, electronic systems...

Cellular and Molecular Approaches to Polymer Synthesis by Bacteria

DTIC Science & Technology

1989-03-01

of biodegradable polymers f rom Pseudowonas oleovorans.....L (See appended research summaries pp. 1-4.) 20. DISTRIBUTIONI/AVAILABILITY OF ABSTRACT 21...during the growth of the organism , polymer production is greatest and harvesting gives maximum PHA vield. Other experiments have also been conducted...Functional PHA from Rhodospirillum and Alcaligenes The major emphasis is to produce functional biodegradable polymers and new, totally biodegradable

Evolution of nitrogen species in landfill leachates under various stabilization states.

PubMed

Zhao, Renzun; Gupta, Abhinav; Novak, John T; Goldsmith, C Douglas

2017-11-01

In this study, nitrogen species in landfill leachates under various stabilization states were investigated with emphasis on organic nitrogen. Ammonium nitrogen was found to be approximately 1300mg/L in leachates from younger landfill units (less than 10years old), and approximately 500mg/L in leachates from older landfill units (up to 30years old). The concentration and aerobic biodegradability of organic nitrogen decreased with landfill age. A size distribution study showed that most organic nitrogen in landfill leachates is <1kDa. The Lowry protein concentration (mg/L-N) was analyzed and showed a strong correlation with the total organic nitrogen (TON, mg/L-N, R 2 =0.88 and 0.98 for untreated and treated samples, respectively). The slopes of the regression curves of untreated (protein=0.45TON) and treated (protein=0.31TON) leachates indicated that the protein is more biodegradable than the other organic nitrogen species in landfill leachates. XAD-8 resin was employed to isolate the hydrophilic fraction of leachate samples, and it was found that the hydrophilic fraction proportion in terms of organic nitrogen decreased with landfill age. Solid-state 15 N nuclear magnetic resonance (NMR) was utilized to identify the nitrogen species. Proteinaceous materials were found to be readily biodegradable, while heterocyclic nitrogen species were found to be resistant to biodegradation. Copyright © 2017 Elsevier Ltd. All rights reserved.

New insights into the environmental photochemistry of 5-chloro-2-(2,4-dichlorophenoxy)phenol (triclosan): reconsidering the importance of indirect photoreactions.

PubMed

Bianco, Angelica; Fabbri, Debora; Minella, Marco; Brigante, Marcello; Mailhot, Gilles; Maurino, Valter; Minero, Claudio; Vione, Davide

2015-04-01

Triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol) is a widely used antimicrobial agent that undergoes fairly slow biodegradation. It is often found in surface waters in both the acidic (HTric) and basic (Tric(-)) forms (pKa ∼8), and it can undergo direct photodegradation to produce several intermediates including a dioxin congener (2,8-dichlorodibenzodioxin, hereafter 28DCDD). The latter is formed from Tric(-) and causes non-negligible environmental concern. Differently from current literature reports, in this paper we show that the direct photolysis would not be the only important transformation pathway of triclosan in surface waters. This is particularly true for HTric, which could undergo very significant reactions with (•)OH and, if the laser-derived quenching rate constants of this work are comparable to the actual reaction rate constants, with the triplet states of chromophoric dissolved organic matter ((3)CDOM*). Model calculations suggest that reaction with (3)CDOM* could be the main HTric phototransformation pathway in deep waters with high dissolved organic carbon (DOC), while reaction with (•)OH could prevail in low-DOC waters. In the case of Tric(-) the direct photolysis is much more important than for HTric, but triplet-sensitised transformation could produce 28DCDD + 27DCDD with higher yield compared to the direct photolysis, and it could play some role as dioxin source in deep waters with elevated DOC. Copyright © 2014 Elsevier Ltd. All rights reserved.

Microbial degradation on glacier surface is the missing piece of environmental fate of pesticides in cold areas

NASA Astrophysics Data System (ADS)

Ambrosini, Roberto; Ferrario, Claudia; Pittino, Francesca; Tagliaferri, Ilario; Gandolfi, Isabella; Bestetti, Giuseppina; Azzoni, Roberto S.; Diolaiuti, Guglielmina A.; Smiraglia, Claudio; Franzetti, Andrea; Villa, Sara

2017-04-01

Organic contaminants deposited on glacier surfaces undergo different partition and degradation processes which determine their environmental fate and accumulation into the trophic chains. Among these processes, biodegradation by supraglacial bacteria has been neglected so far. To assess the relevance of biodegradative processes, in situ microcosm experiments were conducted simulating cryoconite hole systems on an Alpine glacier exposed to the organophosphorus insecticide chlorpyrifos (CPF) as model of xenobiotic molecule which accumulate on glaciers after medium range transports. Results showed that biodegradation is the most efficient process contributing to the removal of CPF on the glacier surface. The high concentrations of CPF in cryoconite and its half-life in the range of 35 - 69 days indicated that biodegradation process can significantly contrast the release of CPF transported on glaciers. Moreover, the metabolic versatility of cryoconite bacteria suggest that these habitats might contribute to the degradation of a wide class of pollutants with different physical-chemical properties. Metagenomics data indicated that photoheterotrophic bacteria might be involved in the biodegradation of CPF by using light to supplement their metabolic demands, thus contributing to the biological removal of CPF without the constrain of using this pesticide as sole energy source. In conclusion. cryoconite might act as a "biofilter" for organic pollutants on glaciers by accumulating them and promoting their biodegradation. Owing to its relevance, the contribution of cryoconite to the removal of organic pollutants should be included in the models predicting the environmental fate of these compounds in cold areas.

An empirical model for prediction of household solid waste generation rate - A case study of Dhanbad, India.

PubMed

Kumar, Atul; Samadder, S R

2017-10-01

Accurate prediction of the quantity of household solid waste generation is very much essential for effective management of municipal solid waste (MSW). In actual practice, modelling methods are often found useful for precise prediction of MSW generation rate. In this study, two models have been proposed that established the relationships between the household solid waste generation rate and the socioeconomic parameters, such as household size, total family income, education, occupation and fuel used in the kitchen. Multiple linear regression technique was applied to develop the two models, one for the prediction of biodegradable MSW generation rate and the other for non-biodegradable MSW generation rate for individual households of the city Dhanbad, India. The results of the two models showed that the coefficient of determinations (R 2 ) were 0.782 for biodegradable waste generation rate and 0.676 for non-biodegradable waste generation rate using the selected independent variables. The accuracy tests of the developed models showed convincing results, as the predicted values were very close to the observed values. Validation of the developed models with a new set of data indicated a good fit for actual prediction purpose with predicted R 2 values of 0.76 and 0.64 for biodegradable and non-biodegradable MSW generation rate respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

Removal of diclofenac from a non-sterile aqueous system using Trametes versicolor with an emphasis on adsorption and biodegradation mechanisms.

PubMed

Stenholm, Åke; Hedeland, Mikael; Arvidsson, Torbjörn; Pettersson, Curt E

2018-03-04

This paper describes the search for procedures through which the xenobiotic pollutant diclofenac can be removed from non-sterile aquatic systems. Specifically, adsorption to solid supports (carriers) in combination with biodegradation by non-immobilized and immobilized white rot fungus Trametes versicolor were investigated. Batch experiments using polyurethane foam (PUF)-carriers resulted in 99.9% diclofenac removal after 4 h, with monolayer adsorption of diclofenac to carrier and glass surfaces accounting for most of the diclofenac decrease. Enzymatic reactions contributed less, accounting for approximately < 0.5% of this decrease. In bioreactor experiments using PUF-carriers, an initial 100% removal was achieved with biodegradation contributing approximately 7%. In batch experiments that utilized polyethylene-carriers with negligible immobilization of Trametes versicolor, a 98% total diclofenac removal was achieved after one week, with a biodegradation contribution of approximately 14%. Five novel enzyme-catalyzed biodegradation products were tentatively identified in the batch-wise and bioreactor experiments using full scan ultra-high-performance liquid chromatography-quadrupole/time of flight mass spectrometry. Both reduction and oxidation products were found, with the contents estimated to be at µg L -1 concentration levels.

Sorbed atrazine shifts into non-desorbable sites of soil organic matter during aging.

PubMed

Park, Jeong-Hun; Feng, Yucheng; Cho, Sung Yong; Voice, Thomas C; Boyd, Stephen A

2004-11-01

Soil-chemical contact time (aging) is an important determinant of the sorption and desorption characteristics of the organic contaminants and pesticides in the environment. The effects of aging on mechanism-specific sorption and desorption of atrazine were studied in soil and clay slurries. Sorption isotherm and desorption kinetic experiments were performed, and soil-water distribution coefficients and desorption rate parameters were evaluated using linear and non-linear sorption equations and a three-site desorption model, respectively. Aging time for sorption of atrazine in sterilized soil and clay slurries ranged from 2 days to 8 months. Atrazine sorption isotherms were nearly linear (r(2)>0.97) and sorption coefficients were strongly correlated to soil organic carbon content. Sorption distribution coefficients (K(d)) increased with increase in age in all five soils studied, but not for K-montmorillonite. Sorption non-linearity did not increase with increase in age except for the Houghton muck soil. Desorption profiles were well described by the three-site desorption model. The equilibrium site fraction (f(eq)) decreased and the non-desorbable site fraction (f(nd)) increased as a function of aging time in all soils. For K-montmorillonite, f(nd) approximately 0 regardless of aging, showing that aging phenomena are sorbent/mechanism specific. In all soils, it was found that when normalized to soil organic matter content, the concentration of atrazine in desorbable sites was relatively constant, whereas that in non-desorbable site increased. This, and the lack of aging effects on desorption from montmorillonite, suggests that sorption into non-desorbable sites of soil organic matter is primary source of increased atrazine sorption in soils during aging.

A new bioseed for determination of wastewater biodegradability: analysis of the experimental procedure.

PubMed

Ballesteros Martín, M M; Esteban García, B; Ortega-Gómez, E; Sánchez Pérez, J A

2014-01-01

A new bioassay proposed in the patent P201300029 was applied to a pre-treated wastewater containing a mixture of commercial pesticides to simulate a recalcitrant industrial wastewater in order to determine its biodegradability. The test uses a mixture of standardized inoculum of the lyophilized bacteria Pseudomonas putida with the proper proportion of salts and minerals. The results highlight that biodegradation efficiency can be calculated using a gross parameter (chemical oxygen demand (COD)) which facilitates the biodegradability determination for routine water biodegradability analysis. The same trend was observed throughout the assay with the dehydrated and fresh inoculums, and only a difference of 5% in biodegradation efficiency (E f) was observed. The obtained results showed that the P. putida biodegradability assay can be used as a commercial test with a lyophilized inoculum in order to monitor the ready biodegradability of an organic pollutant or a WWTP influent. Moreover, a combination of the BOD5/COD ratio and the P. putida biodegradability test is an attractive alternative in order to evaluate the biodegradability enhancement in water pre-treated with advanced oxidation processes (AOPs).

Water quality assessment of a small peri-urban river using low and high frequency monitoring.

PubMed

Ivanovsky, A; Criquet, J; Dumoulin, D; Alary, C; Prygiel, J; Duponchel, L; Billon, G

2016-05-18

The biogeochemical behaviors of small rivers that pass through suburban areas are difficult to understand because of the multi-origin inputs that can modify their behavior. In this context, a monitoring strategy has been designed for the Marque River, located in Lille Metropolitan area of northern France, that includes both low-frequency monitoring over a one-year period (monthly sampling) and high frequency monitoring (measurements every 10 minutes) in spring and summer. Several environmental and chemical parameters are evaluated including rainfall events, river flow, temperature, dissolved oxygen, turbidity, conductivity, nutritive salts and dissolved organic matter. Our results from the Marque River show that (i) it is impacted by both urban and agricultural inputs, and as a consequence, the concentrations of phosphate and inorganic nitrogen have degraded the water quality; (ii) the classic photosynthesis/respiration processes are disrupted by the inputs of organic matter and nutritive salts; (iii) during dry periods, the urban sewage inputs (treated or not) are more important during the day, as indicated by higher river flows and maximal concentrations of ammonium; (iv) phosphate concentrations depend on oxygen contents in the river; (v) high nutrient concentrations result in eutrophication of the Marque River with lower pH and oxygen concentrations in summer. During rainfalls, additional inputs of ammonium, biodegradable organic matter as well as sediment resuspension result in anoxic events; and finally (vi) concentrations of nitrate are approximately constant over the year, except in winter when higher inputs can be recorded. Having better identified the processes responsible for the observed water quality, a more informed remediation effort can be put forward to move this suburban river to a good status of water quality.

Metagenomic characterization of biofilter microbial communities in a full-scale drinking water treatment plant.

PubMed

Oh, Seungdae; Hammes, Frederik; Liu, Wen-Tso

2018-01-01

Microorganisms inhabiting filtration media of a drinking water treatment plant can be beneficial, because they metabolize biodegradable organic matter from source waters and those formed during disinfection processes, leading to the production of biologically stable drinking water. However, which microbial consortia colonize filters and what metabolic capacity they possess remain to be investigated. To gain insights into these issues, we performed metagenome sequencing and analysis of microbial communities in three different filters of a full-scale drinking water treatment plant (DWTP). Filter communities were sampled from a rapid sand filter (RSF), granular activated carbon filter (GAC), and slow sand filter (SSF), and from the Schmutzdecke (SCM, a biologically active scum layer accumulated on top of SSF), respectively. Analysis of community phylogenetic structure revealed that the filter bacterial communities significantly differed from those in the source water and final effluent communities, respectively. Network analysis identified a filter-specific colonization pattern of bacterial groups. Bradyrhizobiaceae were abundant in GAC, whereas Nitrospira were enriched in the sand-associated filters (RSF, SCM, and SSF). The GAC community was enriched with functions associated with aromatics degradation, many of which were encoded by Rhizobiales (∼30% of the total GAC community). Predicting minimum generation time (MGT) of prokaryotic communities suggested that the GAC community potentially select fast-growers (<15 h of MGT) among the four filter communities, consistent with the highest dissolved organic matter removal rate by GAC. Our findings provide new insights into the community phylogenetic structure, colonization pattern, and metabolic capacity that potentially contributes to organic matter removal achieved in the biofiltration stages of the full-scale DWTP. Copyright © 2017 Elsevier Ltd. All rights reserved.

Column studies to assess the effects of climate variables on redox processes during riverbank filtration.

PubMed

Rudolf von Rohr, Matthias; Hering, Janet G; Kohler, Hans-Peter E; von Gunten, Urs

2014-09-15

Riverbank filtration is an established technique used world-wide to produce clean drinking water in a reliable and cost-efficient way. This practice is, however, facing new challenges posed by climate change, as already observed during past heat waves with the local occurrence of anoxic conditions. In this study we investigated the effect of direct (temperature) and indirect (dissolved organic matter (DOM) concentration and composition, flow rate) climate change variables on redox processes (aerobic respiration, denitrification and Mn(III/IV)/Fe(III) reduction) by means of column experiments. Natural river water, modified river water and river water mixed with treated wastewater effluent were used as feed waters for the columns filled with natural sand from a river-infiltration system in Switzerland. Biodegradable dissolved organic matter was mainly removed immediately at the column inlet and particulate organic matter (POM) associated with the natural sand was the main electron donor for aerobic respiration throughout the column. Low infiltration rates (≤0.01 m/h) enhanced the oxygen consumption leading to anoxic conditions. DOM consumption did not seem to be sensitive to temperature, although oxygen consumption (i.e., associated with POM degradation) showed a strong temperature dependence with an activation energy of ∼70 kJmol(-1). Anoxic conditions developed at 30 °C with partial denitrification and formation of nitrite and ammonium. In absence of oxygen and nitrate, Mn(II) was mobilized at 20 °C, highlighting the importance of nitrate acting as a redox buffer under anoxic conditions preventing the reductive dissolution of Mn(III/IV)(hydr)oxides. Reductive dissolution of Fe(III)(hydr)oxides was not observed under these conditions. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of inoculant strain and organic matter content on kinetics of 2,4-dichlorophenoxyacetic acid degradation in soil.

PubMed Central

Greer, L E; Shelton, D R

1992-01-01

We monitored rates of degradation of soluble and sorbed 2,4-dichlorophenoxyacetic acid (2,4-D) in low-organic-matter soil at field capacity amended with 1, 10, or 100 micrograms of 2,4-D per g of wet soil and inoculated with one of two bacterial strains (MI and 155) with similar maximum growth rates (mu max) but significantly different half-saturation growth constants (Ks). Concentrations of soluble 2,4-D were determined by analyzing samples of pore water pressed from soil, and concentrations of sorbed 2,4-D were determined by solvent extraction. Between 65 and 75% of the total 2,4-D was present in the soluble phase at equilibrium, resulting in soil solution concentrations of ca. 8, 60, and 600 micrograms of 2,4-D per ml, respectively. Soluble 2,4-D was metabolized preferentially; this was followed by degradation of both sorbed (after desorption) and soluble 2,4-D. Rates of degradation were comparable for the two strains at soil concentrations of 10 and 100 micrograms of 2,4-D per g; however, at 1 microgram/g of soil, 2,4-D was metabolized more rapidly by the strain with the lower Ks value (strain MI). We also monitored rates of biodegradation of soluble and sorbed 2,4-D in high-organic-matter soil at field capacity amended with 100 micrograms of 2,4-D per g of wet soil and inoculated with the low-Ks strain (strain MI). Ten percent of total 2,4-D was present in the soluble phase, resulting in a soil solution concentration of ca. 30 micrograms of 2,4-D per ml.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1622212

Effect of inoculant strain and organic matter content on kinetics of 2,4-dichlorophenoxyacetic acid degradation in soil.

PubMed

Greer, L E; Shelton, D R

1992-05-01

We monitored rates of degradation of soluble and sorbed 2,4-dichlorophenoxyacetic acid (2,4-D) in low-organic-matter soil at field capacity amended with 1, 10, or 100 micrograms of 2,4-D per g of wet soil and inoculated with one of two bacterial strains (MI and 155) with similar maximum growth rates (mu max) but significantly different half-saturation growth constants (Ks). Concentrations of soluble 2,4-D were determined by analyzing samples of pore water pressed from soil, and concentrations of sorbed 2,4-D were determined by solvent extraction. Between 65 and 75% of the total 2,4-D was present in the soluble phase at equilibrium, resulting in soil solution concentrations of ca. 8, 60, and 600 micrograms of 2,4-D per ml, respectively. Soluble 2,4-D was metabolized preferentially; this was followed by degradation of both sorbed (after desorption) and soluble 2,4-D. Rates of degradation were comparable for the two strains at soil concentrations of 10 and 100 micrograms of 2,4-D per g; however, at 1 microgram/g of soil, 2,4-D was metabolized more rapidly by the strain with the lower Ks value (strain MI). We also monitored rates of biodegradation of soluble and sorbed 2,4-D in high-organic-matter soil at field capacity amended with 100 micrograms of 2,4-D per g of wet soil and inoculated with the low-Ks strain (strain MI). Ten percent of total 2,4-D was present in the soluble phase, resulting in a soil solution concentration of ca. 30 micrograms of 2,4-D per ml.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacterial Community Diversity of Oil-Contaminated Soils Assessed by High Throughput Sequencing of 16S rRNA Genes.

PubMed

Peng, Mu; Zi, Xiaoxue; Wang, Qiuyu

2015-09-24

Soil bacteria play a major role in ecological and biodegradable function processes in oil-contaminated soils. Here, we assessed the bacterial diversity and changes therein in oil-contaminated soils exposed to different periods of oil pollution using 454 pyrosequencing of 16S rRNA genes. No less than 24,953 valid reads and 6246 operational taxonomic units (OTUs) were obtained from all five studied samples. OTU richness was relatively higher in contaminated soils than clean samples. Acidobacteria, Actinobacteria, Bacteroidetes, Chloroflexi, Planctomycetes and Proteobacteria were the dominant phyla among all the soil samples. The heatmap plot depicted the relative percentage of each bacterial family within each sample and clustered five samples into two groups. For the samples, bacteria in the soils varied at different periods of oil exposure. The oil pollution exerted strong selective pressure to propagate many potentially petroleum degrading bacteria. Redundancy analysis (RDA) indicated that organic matter was the highest determinant factor for explaining the variations in community compositions. This suggests that compared to clean soils, oil-polluted soils support more diverse bacterial communities and soil bacterial community shifts were mainly controlled by organic matter and exposure time. These results provide some useful information for bioremediation of petroleum contaminated soil in the future.

The role of clay minerals in the preservation of organic matter in sediments of Qinghai Lake, NW China

USGS Publications Warehouse

Yu, Bingsong; Dong, Hailiang; Jiang, Hongchen; Lv, Guo; Eberl, Dennis D.; Li, Shanying; Kim, Jinwook

2009-01-01

The role of saline lake sediments in preserving organic matter has long been recognized. In order to further understand the preservation mechanisms, the role of clay minerals was studied. Three sediment cores, 25, 57, and 500 cm long, were collected from Qinghai Lake, NW China, and dissected into multiple subsamples. Multiple techniques were employed, including density fractionation, X-ray diffraction, scanning and transmission electron microscopy (SEM and TEM), total organic carbon (TOC) and carbon compound analyses, and surface area determination. The sediments were oxic near the water-sediment interface, but became anoxic at depth. The clay mineral content was as much as 36.8%, consisting mostly of illite, chlorite, and halloysite. The TEM observations revealed that organic matter occurred primarily as organic matter-clay mineral aggregates. The TOC and clay mineral abundances are greatest in the mid-density fraction, with a positive correlation between the TOC and mineral surface area. The TOC of the bulk sediments ranges from 1 to 3% with the non-hydrocarbon fraction being predominant, followed by bitumen, saturated hydrocarbon, aromatic hydrocarbons, and chloroform-soluble bitumen. The bimodal distribution of carbon compounds of the saturated hydrocarbon fraction suggests that organic matter in the sediments was derived from two sources: terrestrial plants and microorganisms/algae. Depthrelated systematic changes in the distribution patterns of the carbon compounds suggest that the oxidizing conditions and microbial abundance near the water-sediment interface promote degradation of labile organic matter, probably in adsorbed form. The reducing conditions and small microbial biomass deeper in the sediments favor preservation of organic matter, because of the less labile nature of organic matter, probably occurring within clay mineral-organic matter aggregates that are inaccessible to microorganisms. These results have important implications for our understanding of mechanisms of organic matter preservation in saline lake sediments.

Thermal Spraying of Bioactive Polymer Coatings for Orthopaedic Applications

NASA Astrophysics Data System (ADS)

Chebbi, A.; Stokes, J.

2012-06-01

Flame sprayed biocompatible polymer coatings, made of biodegradable and non-biodegradable polymers, were investigated as single coatings on titanium and as top coatings on plasma sprayed Hydroxyapatite. Biocompatible polymers can act as drug carriers for localized drug release following implantation. The polymer matrix consisted of a biodegradable polymer, polyhydroxybutyrate 98%/ polyhydroxyvalerate 2% (PHBV) and a non-biodegradable polymer, polymethylmethacrylate (PMMA). Screening tests were performed to determine the suitable range of spraying parameters, followed by a Design of Experiments study to determine the effects of spraying parameters on coating characteristics (thickness, roughness, adhesion, wettability), and to optimize the coating properties accordingly. Coatings characterization showed that optimized flame sprayed biocompatible polymers underwent little chemical degradation, did not produce acidic by-products in vitro, and that cells proliferated well on their surface.

Comparison of biodegradation of poly(ethylene glycol)s and poly(propylene glycol)s.

PubMed

Zgoła-Grześkowiak, Agnieszka; Grześkowiak, Tomasz; Zembrzuska, Joanna; Łukaszewski, Zenon

2006-07-01

The biodegradation of poly(ethylene glycol)s (PEGs) and poly(propylene glycol)s (PPGs), both being major by-products of non-ionic surfactants biodegradation, was studied under the conditions of the River Water Die-Away Test. PEGs were isolated from a water matrix using solid-phase extraction with graphitized carbon black sorbent, then derivatized with phenyl isocyanate and determined by HPLC with UV detection. PPGs were isolated from a water matrix by liquid-liquid extraction with chloroform, then derivatized with naphthyl isocyanate and determined by HPLC with fluorescence detection. The primary biodegradation of both PEGs and PPGs reached approximately 99% during the test. The tests show different biodegradation pathways of PEG and PPG. During PEG biodegradation, their chains are shortened leading to the formation of ethylene glycol and diethylene glycol. During PPG biodegradation, no short-chained biodegradation products were found.

Innovative technology: Slurry-phase biodegradation. Fact sheet (Final)

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

Not Available

1989-11-01

The fact sheet provides technology description, site characteristics affecting treatment feasibility, technology considerations, and technology status for Slurry Phase Biodegradation (SPB). The sheet describes how SPB is potentially effective in treating various organic contaminants.

Organic matter accumulation and community change at the peatland-upland interface: inferences from 14C and 210Pb dated profiles

Treesearch

Ilka E. Bauer; Jagtar S. Bhatti; Christopher Swanston; R. Kelman Wieder; Caroline M. Perston

2009-01-01

Peatland-margin habitats with organic matter accumulation of 40-150 cm make up a significant but poorly quantified portion of Canada's boreal forest region. Spanning the transition between non-wetland forest and fen proper, these ecosystems represent a zone of complex environmental and vegetation change, yet little is known about their ecological function or...

Biodegradability relationships among propylene glycol substances in the Organization for Economic Cooperation and Development ready- and seawater biodegradability tests.

PubMed

West, Robert J; Davis, John W; Pottenger, Lynn H; Banton, Marcy I; Graham, Cynthia

2007-05-01

Eight propylene glycol substances, ranging from 1,2-propanediol to a poly(propylene glycol) (PPG) having number-average molecular weight (M(n)) of 2,700 (i.e., PPG 2700), were evaluated in the Organization for Economic Cooperation and Development (OECD) ready- and seawater biodegradability tests. Uniformity in test parameters, such as inoculum source/density and test substance concentrations, combined with frequent measurements of O2 consumption and CO2 evolution, revealed unexpected biodegradability trends across this family of substances. Biodegradability in both tests decreased with increased number of oxy-propylene repeating units (n = 1, 2, 3, 4) of the oligomeric propylene glycols (PGs). However, this trend was reversed for the PPG polymers, and increased biodegradability was observed with increases of average n to seven, 17, and 34 (M(n) = 425, 1,000, and 2,000, respectively). This relationship between molecular weight and biodegradability was reversed again when average n was incremented from 34 (PPG 2000) to 46 (PPG 2700). Six of the tested substances (n = 1, 2, 3, 7, 17, and 34) met the OECD-specified criteria for "ready biodegradability," whereas the tetrapropylene glycol (n = 4) and PPG 2700 substances failed to meet these criteria. Biodegradation half-lives for these eight substances ranged from 3.8 d (PPG 2000) to 33.2 d (PPG 2700) in the ready test, and from 13.6 (PG) to 410 d (PPG 2700) in seawater. Biodegradation half-lives in seawater were significantly correlated with half-lives determined in the ready test. However, half-lives in both tests were correlated poorly with molecular weight, water solubility, and log K(ow). It is speculated that the molecular conformation of these substances, perhaps more so than these other physicochemical properties, has an important role in influencing biodegradability of the propylene glycol substances.

An equivalent-time-lines model for municipal solid waste based on its compression characteristics.

PubMed

Gao, Wu; Bian, Xuecheng; Xu, Wenjie; Chen, Yunmin

2017-10-01

Municipal solid waste (MSW) demonstrates a noticeable time-dependent stress-strain behavior, which contributes greatly to the settlement of landfills and therefore influences both the storage capacity of landfills and the integrity of internal structures. The long-term compression tests for MSW under different biodegradation conditions were analyzed. It showed that the primary compression can affect the secondary compression due to the biodegradation and mechanical creep. Based on the time-lines model for clays and the compression characteristics of MSW, relationships between MSW's viscous strain rate and equivalent time were established, and then the viscous strain functions of MSW under different biodegradation conditions were deduced, and an equivalent-time-lines model for MSW settlement for two biodegradation conditions was developed, including the Type I model for the enhanced biodegradation condition and the Type II model for the normal biodegradation condition. The simulated compression results of laboratory and field compression tests under different biodegradation conditions were consistent with the measured data, which showed the reliability of both types of the equivalent-time-lines model for MSW. In addition, investigations of the long-term settlement of landfills from the literature indicated that the Type I model is suitable for predicting settlement in MSW landfills with a distinct biodegradation progress of MSW, a high content of organics in MSW, a short fill age or under an enhanced biodegradation environment; while the Type II model is good at predicting settlement in MSW landfills with a distinct progress of mechanical creep compression, a low content of organics in MSW, a long fill age or under a normal biodegradation condition. Furthermore, relationships between model parameters and the fill age of landfills were summarized. Finally, the similarities and differences between the equivalent-time-lines model for MSW and the stress-biodegradation model for MSW were discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Presence or Absence of mlr Genes and Nutrient Concentrations Co-Determine the Microcystin Biodegradation Efficiency of a Natural Bacterial Community

PubMed Central

Lezcano, María Ángeles; Morón-López, Jesús; Agha, Ramsy; López-Heras, Isabel; Nozal, Leonor; Quesada, Antonio; El-Shehawy, Rehab

2016-01-01

The microcystin biodegradation potential of a natural bacterial community coexisting with a toxic cyanobacterial bloom was investigated in a water reservoir from central Spain. The biodegradation capacity was confirmed in all samples during the bloom and an increase of mlrA gene copies was found with increasing microcystin concentrations. Among the 24 microcystin degrading strains isolated from the bacterial community, only 28% showed presence of mlrA gene, strongly supporting the existence and abundance of alternative microcystin degradation pathways in nature. In vitro degradation assays with both mlr+ and mlr− bacterial genotypes (with presence and absence of the complete mlr gene cluster, respectively) were performed with four isolated strains (Sphingopyxis sp. IM-1, IM-2 and IM-3; Paucibacter toxinivorans IM-4) and two bacterial degraders from the culture collection (Sphingosinicella microcystinivorans Y2; Paucibacter toxinivorans 2C20). Differences in microcystin degradation efficiencies between genotypes were found under different total organic carbon and total nitrogen concentrations. While mlr+ strains significantly improved microcystin degradation rates when exposed to other carbon and nitrogen sources, mlr− strains showed lower degradation efficiencies. This suggests that the presence of alternative carbon and nitrogen sources possibly competes with microcystins and impairs putative non-mlr microcystin degradation pathways. Considering the abundance of the mlr− bacterial population and the increasing frequency of eutrophic conditions in aquatic systems, further research on the diversity of this population and the characterization and conditions affecting non-mlr degradation pathways deserves special attention. PMID:27827872

Organic matter controls of iron incorporation in growing sea ice

NASA Astrophysics Data System (ADS)

Janssens, Julie; Meiners, Klaus M.; Townsend, Ashley T.; Lannuzel, Delphine

2018-03-01

This study presents the first laboratory-controlled sea-ice growth experiment conducted under trace metal clean conditions. The role played by organic matter, in the incorporation of iron (Fe) into sea ice was investigated by means of laboratory ice-growth experiments using a titanium cold-finger apparatus. Experiments were also conducted to understand the role of extracellular polymeric substances (EPS) in the enrichment of ammonium in sea ice. Sea ice was grown from several seawater solutions containing different quantities and qualities of particulate Fe (PFe), dissolved Fe (DFe) and organic matter. Sea ice and seawater were analyzed for particulate organic carbon and nitrogen, macro-nutrients, extracellular EPS, PFe and DFe, and particulate aluminium. The experiments showed that biogenic PFe is preferentially incorporated into sea ice compared to lithogenic PFe. Furthermore, sea ice grown from ultra-violet (UV) and non-UV treated seawaters exhibits contrasting incorporation rates of organic matter and Fe. Whereas the effects of UV-treatments were not always significant, we do find indications that the type or organic matter controls the enrichment of Fe in forming sea ice.. Specifically, we come to the conclusion that the incorporation of DFe is favored by the presence of organic ligands in the source solution.

How UV photolysis accelerates the biodegradation and mineralization of sulfadiazine (SD).

PubMed

Pan, Shihui; Yan, Ning; Liu, Xinyue; Wang, Wenbing; Zhang, Yongming; Liu, Rui; Rittmann, Bruce E

2014-11-01

Sulfadiazine (SD), one of broad-spectrum antibiotics, exhibits limited biodegradation in wastewater treatment due to its chemical structure, which requires initial mono-oxygenation reactions to initiate its biodegradation. Intimately coupling UV photolysis with biodegradation, realized with the internal loop photobiodegradation reactor, accelerated SD biodegradation and mineralization by 35 and 71 %, respectively. The main organic products from photolysis were 2-aminopyrimidine (2-AP), p-aminobenzenesulfonic acid (ABS), and aniline (An), and an SD-photolysis pathway could be identified using C, N, and S balances. Adding An or ABS (but not 2-AP) into the SD solution during biodegradation experiments (no UV photolysis) gave SD removal and mineralization rates similar to intimately coupled photolysis and biodegradation. An SD biodegradation pathway, based on a diverse set of the experimental results, explains how the mineralization of ABS and An (but not 2-AP) provided internal electron carriers that accelerated the initial mono-oxygenation reactions of SD biodegradation. Thus, multiple lines of evidence support that the mechanism by which intimately coupled photolysis and biodegradation accelerated SD removal and mineralization was through producing co-substrates whose oxidation produced electron equivalents that stimulated the initial mono-oxygenation reactions for SD biodegradation.

A new biostimulation approach based on the concept of remaining P for soil bioremediation.

PubMed

Júlio, Aline Daniela Lopes; Fernandes, Rita de Cássia Rocha; Costa, Maurício Dutra; Neves, Júlio César Lima; Rodrigues, Edmo Montes; Tótola, Marcos Rogério

2018-02-01

C:N:P ratio is generally adopted to estimate the amount of nitrogen and phosphorus to be added to soils to accelerate biodegradation of organic contaminants. However, differences in P fixation among soils lead to varying amounts of available P when a specific dose of the element is applied to different soils. Thus, the application of fertilizers to achieve a previously established C:P ratio leads to biodegradation rates that can be lower than the theoretical maximum. In this study, we developed an equation to estimate the dose of P required to maximize organic contaminant biodegradation in soils as a function of remaining P (P-rem), using diesel as a model contaminant. The soils were contaminated with diesel and received six doses of P. CO 2 emission was used to estimate biodegradation of hydrocarbons. Biodegradation increased with P doses. The P level that provided the highest hydrocarbon biodegradation rate showed linear and negative correlation with P-rem. The result shows that the requirement for P decreases as the P-rem of the soil increases (or the P-fixing capacity decreases). The dose of P recommended to maximize hydrocarbon biodegradation rate in soil can be estimated by the formula P (mg/dm 3 ) = 436.5-5.39 × P-rem (mg/L). Copyright © 2017 Elsevier Ltd. All rights reserved.

Assessing the required additional organic inputs to soils to reach the 4 per 1000 objective at the global scale: a RothC project

NASA Astrophysics Data System (ADS)

Lutfalla, Suzanne; Skalsky, Rastislav; Martin, Manuel; Balkovic, Juraj; Havlik, Petr; Soussana, Jean-François

2017-04-01

The 4 per 1000 Initiative underlines the role of soil organic matter in addressing the three-fold challenge of food security, adaptation of the land sector to climate change, and mitigation of human-induced GHG emissions. It sets an ambitious global target of a 0.4% (4/1000) annual increase in top soil organic carbon (SOC) stock. The present collaborative project between the 4 per 1000 research program, INRA and IIASA aims at providing a first global assessment of the translation of this soil organic carbon sequestration target into the equivalent organic matter inputs target. Indeed, soil organic carbon builds up in the soil through different processes leading to an increased input of carbon to the system (by increasing returns to the soil for instance) or a decreased output of carbon from the system (mainly by biodegradation and mineralization processes). Here we answer the question of how much extra organic matter must be added to agricultural soils every year (in otherwise unchanged climatic conditions) in order to guarantee a 0.4% yearly increase of total soil organic carbon stocks (40cm soil depth is considered). We use the RothC model of soil organic matter turnover on a spatial grid over 10 years to model two situations for croplands: a first situation where soil organic carbon remains constant (system at equilibrium) and a second situation where soil organic matter increases by 0.4% every year. The model accounts for the effects of soil type, temperature, moisture content and plant cover on the turnover process, it is run on a monthly time step, and it can simulate the needed organic input to sustain a certain SOC stock (or evolution of SOC stock). These two SOC conditions lead to two average yearly plant inputs over 10 years. The difference between the two simulated inputs represent the additional yearly input needed to reach the 4 per 1000 objective (input_eq for inputs needed for SOC to remain constant; input_4/1000 for inputs needed for SOC to reach the 4 per 1000 target). A spatial representation of this difference shows the distribution of the required returns to the soil. This first tool will provide the basis for the next steps: choosing and implementing practices to obtain the required additional input. Results will be presented from simulations at the regional scale (country: Slovakia) and at the global scale (0,5° grid resolution). Soil input data comes from the HWSD, climatic input data comes from AgMERRA climate dataset averaged of a 30 years period (1980-2010). They show that, at the global scale, given some data corrections which will be presented and discussed, the 4 per 1000 increase in top soil organic carbon can be reached with a median additional input of +0.89 tC/ha/year for cropland soils.

Importance of Xanthobacter autotrophicus in toluene biodegradation within a contaminated stream.

PubMed

Tay, S T; Hemond, H F; Polz, M F; Cavanaugh, C M; Krumholz, L R

1999-02-01

Toluene-degrading strains T101 and T102 were isolated from rock surface biomass in a toluene-contaminated freshwater stream. These organisms were present at a density of 5.5 x 10(6) cells/g of rock surface biomass. Both are aerobic, rod-shaped, Gram-negative, non-motile, catalase-positive, oxidase-positive, with yellow pigments, and can grow on benzene. Phylogenetic analyses show that strains T101 and T102 have 16S rDNA sequences identical to Xanthobacter autotrophicus. Fatty acid analyses indicate that they are different strains of the same species Xanthobacter autotrophicus, and that they have high levels of cis-11-octadecenoic acid and cis-9-hexadecenoic acid; 3-hydroxyhexadecanoic acid is the major hydroxy fatty acid present. Strains T101 and T102 had maximal velocities (Vmax) for toluene biodegradation of 3.8 +/- 0.5 and 28.3 +/- 2.2 mumoles toluene/mgprotein-hr, and half-saturation constants (Ks) of 0.8 +/- 0.5 and 11.5 +/- 2.4 microM, respectively. Strain T102 has a higher capacity than strain T101 to degrade toluene, and kinetic calculations suggest that strain T102 may be a major contributor to toluene biodegradation in the stream.

Biodegradable Plastic Mulch Films: Impacts on Soil Microbial Communities and Ecosystem Functions

PubMed Central

Bandopadhyay, Sreejata; Martin-Closas, Lluis; Pelacho, Ana M.; DeBruyn, Jennifer M.

2018-01-01

Agricultural plastic mulch films are widely used in specialty crop production systems because of their agronomic benefits. Biodegradable plastic mulches (BDMs) offer an environmentally sustainable alternative to conventional polyethylene (PE) mulch. Unlike PE films, which need to be removed after use, BDMs are tilled into soil where they are expected to biodegrade. However, there remains considerable uncertainty about long-term impacts of BDM incorporation on soil ecosystems. BDMs potentially influence soil microbial communities in two ways: first, as a surface barrier prior to soil incorporation, indirectly affecting soil microclimate and atmosphere (similar to PE films) and second, after soil incorporation, as a direct input of physical fragments, which add carbon, microorganisms, additives, and adherent chemicals. This review summarizes the current literature on impacts of plastic mulches on soil biological and biogeochemical processes, with a special emphasis on BDMs. The combined findings indicated that when used as a surface barrier, plastic mulches altered soil microbial community composition and functioning via microclimate modification, though the nature of these alterations varied between studies. In addition, BDM incorporation into soil can result in enhanced microbial activity and enrichment of fungal taxa. This suggests that despite the fact that total carbon input from BDMs is minuscule, a stimulatory effect on microbial activity may ultimately affect soil organic matter dynamics. To address the current knowledge gaps, long term studies and a better understanding of impacts of BDMs on nutrient biogeochemistry are needed. These are critical to evaluating BDMs as they relate to soil health and agroecosystem sustainability. PMID:29755440

Sorption and biodegradability of sludge bacterial extracellular polymers in soil and their influence on soil copper behavior.

PubMed

Zhou, L X; Zhou, S G; Zhan, X H

2004-01-01

Bacterial extracellular polymers (BEP) affect the translocation and fate of organic and inorganic pollutants in terrestrial and aquatic ecosystems. In this study, BEP from activated sludge was compared with sludge dissolved organic matter (DOM) in terms of behavior and effects on the mobilization and bioavailability of Cu in a well-aged Cu-contaminated orchard sandy loam. Addition of sludge BEP (10-200 mg dissolved organic carbon [DOC] L(-1)) to the soil resulted in 1.6- to 12.8-fold-higher soil soluble Cu concentration over the control and 1.3- to 2.2-fold over sludge DOM of the same concentration. Consequently, the Cu uptake by the ryegrass (Lolium perenne L., cv. Target) grown in the soil was increased by 31% due to interval watering of 100 mg DOC L(-1) of sludge BEP solution in a 35-d period. The influence of sludge BEP on mobilizing soil Cu could be maintained as long as 60 d or more, depending on BEP biodegradation status. The findings that sludge BEP promoted Cu mobilization and bioavailability could be attributed to less adsorption of BEP by soil, slow degradation, and higher affinity with Cu. For example, after 3 wk of aerobic incubation, the soluble Cu present in the sludge DOM-treated soil was reduced to about the level of the control, while the concentration of soluble Cu in BEP-treated soil was 6.2 times higher than that in the control. Therefore, sludge BEP could act as a facilitated-transport carrier of Cu. The environmental risk of Cu should receive much attention if BEP is incorporated into soils.

Modelling of composting process of different organic waste at pilot scale: Biodegradability and odor emissions.

PubMed

Gutiérrez, M C; Siles, J A; Diz, J; Chica, A F; Martín, M A

2017-01-01

The composting process of six different compostable substrates and one of these with the addition of bacterial inoculums carried out in a dynamic respirometer was evaluated. Despite the heterogeneity of the compostable substrates, cumulative oxygen demand (OD, mgO 2 kgVS) was fitted adequately to an exponential regression growing until reaching a maximum in all cases. According to the kinetic constant of the reaction (K) values obtained, the wastes that degraded more slowly were those containing lignocellulosic material (green wastes) or less biodegradable wastes (sewage sludge). The odor emissions generated during the composting processes were also fitted in all cases to a Gaussian regression with R 2 values within the range 0.8-0.9. The model was validated representing real odor concentration near the maximum value against predicted odor concentration of each substrate, (R 2 =0.9314; 95% prediction interval). The variables of maximum odor concentration (ou E /m 3 ) and the time (h) at which the maximum was reached were also evaluated statistically using ANOVA and a post-hoc Tukey test taking the substrate as a factor, which allowed homogeneous groups to be obtained according to one or both of these variables. The maximum oxygen consumption rate or organic matter degradation during composting was directly related to the maximum odor emission generation rate (R 2 =0.9024, 95% confidence interval) when only the organic wastes with a low content in lignocellulosic materials and no inoculated waste (HRIO) were considered. Finally, the composting of OFMSW would produce a higher odor impact than the other substrates if this process was carried out without odor control or open systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

Self-organizing biochemical cycle in dynamic feedback with soil structure

NASA Astrophysics Data System (ADS)

Vasilyeva, Nadezda; Vladimirov, Artem; Smirnov, Alexander; Matveev, Sergey; Tyrtyshnikov, Evgeniy; Yudina, Anna; Milanovskiy, Evgeniy; Shein, Evgeniy

2016-04-01

In the present study we perform bifurcation analysis of a physically-based mathematical model of self-organized structures in soil (Vasilyeva et al., 2015). The state variables in this model included microbial biomass, two organic matter types, oxygen, carbon dioxide, water content and capillary pore size. According to our previous experimental studies, organic matter affinity to water is an important property affecting soil structure. Therefore, organic matter wettability was taken as principle distinction between organic matter types in this model. It considers general known biological feedbacks with soil physical properties formulated as a system of parabolic type non-linear partial differential equations with elements of discrete modeling for water and pore formation. The model shows complex behavior, involving emergence of temporal and spatial irregular auto-oscillations from initially homogeneous distributions. The energy of external impact on a system was defined by a constant oxygen level on the boundary. Non-linear as opposed to linear oxygen diffusion gives possibility of modeling anaerobic micro-zones formation (organic matter conservation mechanism). For the current study we also introduced population competition of three different types of microorganisms according to their mobility/feeding (diffusive, moving and fungal growth). The strongly non-linear system was solved and parameterized by time-optimized algorithm combining explicit and implicit (matrix form of Thomas algorithm) methods considering the time for execution of the evaluated time-step according to accuracy control. The integral flux of the CO2 state variable was used as a macroscopic parameter to describe system as a whole and validation was carried out on temperature series of moisture dependence for soil heterotrophic respiration data. Thus, soil heterotrophic respiration can be naturally modeled as an integral result of complex dynamics on microscale, arising from biological processes formulated as a sum of state variables products, with no need to introduce any saturation functions, such as Mikhaelis-Menten type kinetics, inside the model. Analyzed dynamic soil model is being further developed to describe soil structure formation and its effect on organic matter decomposition at macro-scale, to predict changes with external perturbations. To link micro- and macro-scales we additionally model soil particles aggregation process. The results from local biochemical soil organic matter cycle serve as inputs to aggregation process, while the output aggregate size distributions define physical properties in the soil profile, these in turn serve as dynamic parameters in local biochemical cycles. The additional formulation is a system of non-linear ordinary differential equations, including Smoluchowski-type equations for aggregation and reaction kinetics equations for coagulation/adsorption/adhesion processes. Vasilyeva N.A., Ingtem J.G., Silaev D.A. Nonlinear dynamical model of microbial growth in soil medium. Computational Mathematics and Modeling, vol. 49, p.31-44, 2015 (in Russian). English version is expected in corresponding vol.27, issue 2, 2016.

Application of the IAS theory combining to a three compartments description of natural organic matter to the adsorption of atrazine or diuron on activated carbon.

PubMed

Baudu, M; Raveau, D; Guibaud, G

2004-07-01

The study of natural organic matter (NOM) adsorption on an activated carbon showed that equilibrium cannot be described according to a simple model such as a Freundlich isotherm and confirms the need for a closer description of the organic matter to simulate the competitive adsorption with micropollutants. A representation of the organic matter in three fractions is chosen: non-adsorbable, weak and strong adsorbable. The Ideal Adsorbed Solution Theory (IAST) can, under restrictive conditions, be used to effectively predict the competition between the pesticides and the organic matter. Therefore, it was noted that the model simulated with good precision the competition between atrazine or diuron and natural organic matter in aqueous solution for two activated carbons (A and B). The same parameters for the modeling of organic matter adsorption (Freudlich constants for two absorbable fractions) are used with the two pesticides. However, IAST does not allow correct modeling of pesticide adsorption onto two other (C and D) activated carbons in solution in natural water to be described. IAS theory does not reveal competition between diuron and NOM and pore blockage mechanism by the NOM is proposed as the major effect for the adsorption capacity reduction. However, the difference observed between the two pesticides could be due to in addition to the pore blockage effect, a particular phenomenon with the diuron, especially with D activated carbon. We can suppose specific interactions between the diuron and the adsorbed organic matter and a competition between adsorption sites of NOM and activated carbon surface.

Current approaches for the assessment of in situ biodegradation.

PubMed

Bombach, Petra; Richnow, Hans H; Kästner, Matthias; Fischer, Anko

2010-04-01

Considering the high costs and technical difficulties associated with conventional remediation strategies, in situ biodegradation has become a promising approach for cleaning up contaminated aquifers. To verify if in situ biodegradation of organic contaminants is taking place at a contaminated site and to determine if these processes are efficient enough to replace conventional cleanup technologies, a comprehensive characterization of site-specific biodegradation processes is essential. In recent years, several strategies including geochemical analyses, microbial and molecular methods, tracer tests, metabolite analysis, compound-specific isotope analysis, and in situ microcosms have been developed to investigate the relevance of biodegradation processes for cleaning up contaminated aquifers. In this review, we outline current approaches for the assessment of in situ biodegradation and discuss their potential and limitations. We also discuss the benefits of research strategies combining complementary methods to gain a more comprehensive understanding of the complex hydrogeological and microbial interactions governing contaminant biodegradation in the field.

Recent developments in broadly applicable structure-biodegradability relationships.

PubMed

Jaworska, Joanna S; Boethling, Robert S; Howard, Philip H

2003-08-01

Biodegradation is one of the most important processes influencing concentration of a chemical substance after its release to the environment. It is the main process for removal of many chemicals from the environment and therefore is an important factor in risk assessments. This article reviews available methods and models for predicting biodegradability of organic chemicals from structure. The first section of the article briefly discusses current needs for biodegradability estimation methods related to new and existing chemicals and in the context of multimedia exposure models. Following sections include biodegradation test methods and endpoints used in modeling, with special attention given to the Japanese Ministry of International Trade and Industry test; a primer on modeling, describing the various approaches that have been used in the structure/biodegradability relationship work, and contrasting statistical and mechanistic approaches; and recent developments in structure/biodegradability relationships, divided into group contribution, chemometric, and artificial intelligence approaches.

Sorption and biodegradation of organic micropollutants during river bank filtration: a laboratory column study.

PubMed

Bertelkamp, C; Reungoat, J; Cornelissen, E R; Singhal, N; Reynisson, J; Cabo, A J; van der Hoek, J P; Verliefde, A R D

2014-04-01

This study investigated sorption and biodegradation behaviour of 14 organic micropollutants (OMP) in soil columns representative of the first metre (oxic conditions) of the river bank filtration (RBF) process. Breakthrough curves were modelled to differentiate between OMP sorption and biodegradation. The main objective of this study was to investigate if the OMP biodegradation rate could be related to the physico-chemical properties (charge, hydrophobicity and molecular weight) or functional groups of the OMPs. Although trends were observed between charge or hydrophobicity and the biodegradation rate for charged compounds, a statistically significant linear relationship for the complete OMP mixture could not be obtained using these physico-chemical properties. However, a statistically significant relationship was obtained between biological degradation rates and the OMP functional groups. The presence of ethers and carbonyl groups will increase biodegradability, while the presence of amines, ring structures, aliphatic ethers and sulphur will decrease biodegradability. This predictive model based on functional groups can be used by drinking water companies to make a first estimate whether a newly detected compound will be biodegraded during the first metre of RBF or that additional treatment is required. In addition, the influence of active and inactive biomass (biosorption), sand grains and the water matrix on OMP sorption was found to be negligible under the conditions investigated in this study. Retardation factors for most compounds were close to 1, indicating mobile behaviour of these compounds during soil passage. Adaptation of the biomass towards the dosed OMPs was not observed for a 6 month period, implying that new developed RBF sites might not be able to biodegrade compounds such as atrazine and sulfamethoxazole in the first few months of operation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Tapping bioremediation's potential -- A matter of sweat and tiers

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

Merski, A.T.; Griffin, W.M.

Bioremediation's potential for treating environmental contamination is gaining greater recognition among regulators and the regulated community. For example, biological treatment is routinely applied to municipal wastewater, which typically contains readily biodegradable materials. Industrial wastewaters, by contrast, often contain higher concentrations of materials that present unique challenges to biological treatment. In both areas, biological treatment has succeeded by using contained, relatively controlled systems engineered to optimize performance of the biological component. Uncontrolled releases into such matrices as soil, and fresh and marine waters increase the complexity of the biological challenge, requiring development of novel products and procedures for efficient biological treatmentmore » and monitoring. One of the goals of the National Environmental Technology Applications Corporation (NETAC; Pittsburgh) is to support scientific development of bioremediation technology. NETAC is a non-profit corporation formed in 1988 through a cooperative agreement between EPA and the University of Pittsburgh Trust. Its overall mission is to accelerate development, application and commercialization of priority environmental technologies for national and international markets. NETAC provides technical and business expertise to assist in evaluating, commercializing and publicizing new environmental technologies. The organization assumes no financial interest in any technology but provides independent third-party support and analysis on a fee-for-service basis to technology users and developers.« less

Soil Physical Characteristics and Biological Indicators of Soil Quality Under Different Biodegradable Mulches

NASA Astrophysics Data System (ADS)

Schaeffer, S. M.; Flury, M.; Sintim, H.; Bandopadhyay, S.; Ghimire, S.; Bary, A.; DeBruyn, J.

2015-12-01

Application of conventional polyethylene (PE) mulch in crop production offers benefits of increased water use efficiency, weed control, management of certain plant diseases, and maintenance of a micro-climate conducive for plant growth. These factors improve crop yield and quality, but PE must be retrieved and safely disposed of after usage. Substituting PE with biodegradable plastic mulches (BDM) would alleviate disposal needs, and is potentially a more sustainable practice. However, knowledge of potential impacts of BDMs on agricultural soil ecosystems is needed to evaluate sustainability. We (a) monitored soil moisture and temperature dynamics, and (b) assessed soil quality upon usage of different mulches, with pie pumpkin (Cucurbita pepo) as the test crop. Experimental field trials are ongoing at two sites, one at Northwestern Washington Research and Extension Center, Mount Vernon, WA, and the other at East Tennessee Research and Education Center, Knoxville, TN. The treatments constitute four different commercial BDM products, one experimental BDM; no mulch and PE served as the controls. Soil quality parameters being examined include: organic matter content, aggregate stability, water infiltration rate, CO2 flux, pH, and extracellular enzyme activity. In addition, lysimeters were installed to examine the soil water and heat flow dynamics. We present baseline and the first field season results from this study. Mulch cover appeared to moderate soil temperatures, but biodegradable mulches also appeared to lose water more quickly than PE. All mulch types, with the exception of cellulose, reduced the diurnal fluctuations in soil temperature at 10cm depth from 1 to 4ºC. However, volumetric water content ranged from 0.10 to 0.22 m3 m-3 under the five biodegradable mulches compared to 0.22 to 0.28 m3 m-3 under conventional PE. Results from the study will be useful for management practices by providing knowledge on how different mulches impact soil physical and biological properties which are important indicators of sustainability.

The assessment of the energetic compound 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-Hexaazaisowurtzitane (CL-20) degradability in soil.

PubMed

Strigul, Nikolay; Braida, Washington; Christodoulatos, Christos; Balas, Wendy; Nicolich, Steven

2006-01-01

CL-20 is a relatively new energetic compound with applications in explosive and propellant formulations. Currently, information about the fate of CL-20 in ecological systems is scarce. The aim of this study is to evaluate the biodegradability of CL-20 in soil environments. Four soils were used where initial CL-20 concentrations (above water solubility) ranged from 125 to 1500 mg of CL-20 per kg dry soil (corresponding to the concentrations derived from unexploded ordnance, low order detonation, or manufacturing spills). CL-20 appears to be biodegradable in soil under anaerobic conditions, and additions of organic substrates can substantially accelerate this process. However, CL-20 is not degraded in soil under aerobic conditions kept in the dark at temperatures up to 30 degrees C without organic amendments. Additions of starch or cellulose promote the biodegradation of CL-20 under aerobic conditions. Soil microbial community mediated biodegradation and plant uptake appears to enhance CL-20 biodegradation, the latter suggesting a possible route for CL-20 to entry in the food chain.

Effects of glucose on microcystin-LR removal and the bacterial community composition through anoxic biodegradation in drinking water sludge.

PubMed

Ma, Guangxiang; Pei, Haiyan; Hu, Wenrong; Xu, Xiangchao; Ma, Chunxia; Pei, Ruoting

2016-01-01

To enhance the degradation efficiency of microcystin (MC) in drinking water sludge (DWS), the underlying mechanisms between organic carbon (glucose) and the biodegradation of MC-LR under anoxic conditions were investigated by polymerase chain reaction-denaturing gradient gel electrophoresis technology. The addition of glucose reduced the rate of the MC-LR biodegradation indicating the occurrence of inhibition of degradation, and an increased inhibition was observed with increases in glucose concentration (0-10,000 mg/L). In addition, the community analysis indicated that the variety and the number of the microbes increased with the concentration of glucose amended (0 -1000 mg/L), but they decreased substantially with the addition of 10,000 mg/L of glucose. The phyla Firmicutes, Proteobacteria and Chloroflexi were found to be the dominant. Methylobacterium and Sphingomonas were MC-degrading bacteria and used glucose as a prior carbon source instead of MC, resulting in the decrease in the MC-LR biodegradation rate under anoxic conditions. Thus, reducing organic carbon could improve the anoxic biodegradation efficiency of MC in DWS.