Download or read book Biodegradation of Chlorinated Ethenes in Mixed Waste Streams written by and published by . This book was released on 2004 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes research conducted from 04/01/01 to 08/31/04 with support from the US Army Research Office DoD-EPSCoR program. The goal of the research was to study the biodegradation of chloroethenes under serial anaerobic/aerobic conditions. In the system used water flowed through a contact chamber containing chloroethenes. Contaminated water was then pumped through a sediment column. From the sediment column the water flowed into an aerated chamber. Chloroethenes concentrations were determined in samples from the contact chamber the sediment column and the aerobic chamber. We tested means for establishing anaerobiosis in the sediment column two sparging gas mixtures addition of lactate as a growth substrate control of conditions in the aerobic chamber and the presence of a hydrocarbon fuel mixture as a co-contaminant. Results indicated that a N2:H2 gas mixture stimulated POE degradation. We also found that the addition of exogenous lactic acid (2 mM) and the presence of petroleum hydrocarbons in reactor feed water resulted in 99.6% removal of PCE and 99.2% reduction in the total molar concentration of chloroethenes. In the last year of the research we established mixed microbial cultures in which vinyl chloride disappearance was concomitant with an increase in chloride concentration and biomass accumulation.

Download or read book Handbook on Biodegradation and Biological Treatment of Hazardous Organic Compounds written by M.H. van Agteren and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 463 pages. Available in PDF, EPUB and Kindle. Book excerpt: The introduction of synthetic organic chemicals into the environment during the last few decades has given rise to major concern about the ecotoxicological effects and ultimate fate of these compounds. The pollutants that are considered to be most hazardous because of their intrinsic toxicity, high exposure level, or recalcitrant behavior in the environment have been placed on blacklists and other policy priority lists. The fate of synthetic compounds that enter the environment is mainly determined by their rate of biodegradation, which therefore also has a major effect on the degree of bioaccumulation and the risk of ecotoxicological effects. The degree and rate of biodegradation is also of critical importance for the feasibility of biological techniques to clean up contaminated sites and waste streams. The biodegradation of xenobiotics has thus been the subject of numerous studies, which resulted in thousands of publications in scientific journals, books, and conference proceedings. These studies led to a deeper understanding of the diversity of biodegradation processes. As a result, it has become possible to enhance the rate of degradation of recalcitrant pollutants during biological treatment and to design completely new treatment processes. At present, much work is being done to expand the range of pollutants to which biodegradation can be applied, and to make treatment techniques less expensive and better applicable for waste streams which are difficult to handle.

Download or read book Biodegradation of Chlorinated Ethenes at a Karst Site in Middle Tennessee written by Thomas Duane Byl and published by . This book was released on 2000 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Biodegradation of Chlorinated Organics in a Mixed Substrate Environment written by Anastasios Ch Papanastasiou and published by . This book was released on 1981 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bioremediation of Chlorinated Solvents written by Robert E. Hinchee and published by . This book was released on 1995 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soil and groundwater contamination stemming from the release of various chlorinated compounds into the environment is a significant and difficult site remediation challenge. The articles in this collection discuss the use of aerobic and anaerobic biological degradation to dehalogenate sites contaminated with pesticides and chlorinated solvents such as trichloroethylene, tetrachloroethene, tetrachloromethene, perchloroethylene, carbon tetrachloride, pentachlorophenol, and chlorinated benzene. Bench- and field-scale studies of the biological processes associated with in situ dechlorination of soil and aquifers are described. Discussed are the uses of microcosm studies and numerical simulation of dechlorination to manage system operation. Site characteristics (e.g., hydraulic properties, temperature, nitrogen availability) and their effect on the stability of the methanotrophic community are examined. Methods discussed include the use of air venting, alternative electron donors, biofilm reactors, surfactants, municipal digester sludge, iron enhancement, and sulfate reduction to improve conditions for the microbial consortia that effect dechlorination.

Download or read book Toxicity and Biodegradation of Chlorinated Hydrocarbons written by Debora Ellen Luehrs and published by . This book was released on 1982 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book In Situ Remediation of Chlorinated Solvent Plumes written by Hans F. Stroo and published by Springer Science & Business Media. This book was released on 2010-09-10 with total page 807 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the late 1970s and early 1980s, our nation began to grapple with the legacy of past disposal practices for toxic chemicals. With the passage in 1980 of the Comprehensive Envir- mental Response, Compensation, and Liability Act (CERCLA), commonly known as Sup- fund, it became the law of the land to remediate these sites. The U. S. Department of Defense (DoD), the nation’s largest industrial organization, also recognized that it too had a legacy of contaminated sites. Historic operations at Army, Navy, Air Force, and Marine Corps facilities, ranges, manufacturing sites, shipyards, and depots had resulted in widespread contamination of soil, groundwater, and sediment. While Superfund began in 1980 to focus on remediation of heavily contaminated sites largely abandoned or neglected by the private sector, the DoD had already initiated its Installation Restoration Program in the mid-1970s. In 1984, the DoD began the Defense Environmental Restoration Program (DERP) for contaminated site assessment and remediation. Two years later, the U. S. Congress codified the DERP and directed the Secretary of Defense to carry out a concurrent program of research, development, and demonstration of innovative remediation technologies. As chronicled in the 1994 National Research Council report, “Ranking Hazardous-Waste Sites for Remedial Action,” our early estimates on the cost and suitability of existing techn- ogies for cleaning up contaminated sites were wildly optimistic. Original estimates, in 1980, projected an average Superfund cleanup cost of a mere $3.

Download or read book Selected Water Resources Abstracts written by and published by . This book was released on 1991 with total page 882 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effect of Chlorinated Ethene Biodegradation on Growth Rates of Methanotrophic Bacteria in Biofilms and Mixed Cultures written by James Eric Anderson and published by . This book was released on 1996 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aerobic Biodegradation of Chlorinated Ethenes in Groundwater Exposed to Sequential Anaerobic and Aerobic Conditions written by Siew-Ching Chin and published by . This book was released on 2003 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Anaerobic Biodegradation of Chlorinated Benzenes and Hexachlorocyclohexane by Mixed Microbial Cultures Derived from Contaminated Field Sites written by Luz Adriana Puentes Jacome and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Biodegradation of Chlorinated Ethenes at a Karst Site in Middle Tennessee written by Thomas Duane Byl and published by . This book was released on 2000 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Applied and Environmental Microbiology written by and published by . This book was released on 1999 with total page 1028 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Organohalide Respiring Bacteria written by Lorenz Adrian and published by Springer. This book was released on 2016-08-03 with total page 620 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book summarizes the current state of knowledge concerning bacteria that use halogenated organic compounds as respiratory electron acceptors. The discovery of organohalide-respiring bacteria has expanded the range of electron acceptors used for energy conservation, and serves as a prime example of how scientific discoveries are enabling innovative engineering solutions that have transformed remediation practice. Individual chapters provide in-depth background information on the discovery, isolation, phylogeny, biochemistry, genomic features, and ecology of individual organohalide-respiring genera, including Dehalococcoides, Dehalogenimonas, Dehalobacter, Desulfitobacterium and Sulfurospirillum, as well as organohalide-respiring members of the Deltaproteobacteria. The book introduces readers to the fascinating biology of organohalide-respiring bacteria, offering a valuable resource for students, engineers and practitioners alike.

Download or read book Reductive Dechlorination of Chlorinated Ethenes by Mixed Anaerobic Consortia written by Bhaskar Ballapragada and published by . This book was released on 1996 with total page 654 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effects of Fe III Reduction on Biodegradation of Fuel Oxygenates and Chlorinated Ethenes written by Na Wei and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Fuel oxygenates, methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA), and chlorinated ethenes (TCE, cis-DCE and VC) are two groups of contaminants prevalent in groundwater systems. Fe(III) reducing conditions are dominant in many sedimentary environments. However, the effects of Fe(III) reduction on biotransformation of MTBE/TBA and chlorinated ethenes are not well understood. This research investigated the biodegradation of these contaminants and related microbial ecology under Fe(III)-reducing conditions in both sediment microcosms and enrichment cultures. The primary limitation to understanding anaerobic MTBE biodegradation is the lack of liquid cultures with consistent activity. This study enriched three distinct MTBE-degrading, anaerobic cultures from contaminated aquifer material, and they use anthraquinone-2,6-disulfonate, sulfate and fumarate as the terminal electron acceptor, respectively. Phylogenetic analyses based on 16S rRNA gene suggested novel microorganisms involved in anaerobic MTBE biodegradation. These cultures are the first stable, sediment-free anaerobic MTBE-degrading cultures, which provide model systems for mechanistic studies of anaerobic MTBE biodegradation. Substantial [U-14C]-TBA mineralization occurred under Fe(III)-reducing conditions. The TBA biodegradation activity was correlated with the abundance of one dominant clone, which is closely associated with organisms belonging to the Alphaproteobacteria. The results provide the original evidence of the stimulative effect of Fe(III) reduction on anaerobic TBA mineralization, and give initial insight to the organisms that may catalyze the anaerobic TBA mineralization reactions. The experimental study on the effects of Fe(III) reduction on reductive dechlorination demonstrated that Fe(III) reduction did not inhibit complete dechlorination, which is in contrast to the common opinion that TCE dechlorination will be inhibited wherever there is bioavailable Fe(III). Fe(III) speciation has an impact on daughter product distribution and dechlorination kinetics. Quantitative PCR analysis revealed that Dehalococcoides and Geobacteraceae organisms were enriched concurrently in the dechlorinating Fe(III)-reducing sediments/cultures; Dehalococcoides abundance in the presence of Fe(III) was not significantly different from that in the cultures without Fe(III), meaning Fe(III) reducers would not outcompete and inhibit Dehalococcoides growth. Also, Fe(III) reduction may stimulate growth of G. lovleyi like organisms and contribute to TCE dechlorination to cis-DCE. Enrichment culture study demonstrated that Fe(III) reduction poised the hydrogen concentration at an appropriate steady-state that is within the ideal range for reductive dechlorination when acetate was amended as the sole electron donor. 10X excessive electron donor addition did not facilitate chlorinated ethene dechlorination, but led to considerably high methane production and enrichment of methanogens. The results suggest that adding surplus electron donor will not only cause substrate wastage and unnecessary cost in bioremediation, but also have adverse effects such as enhanced methane release.

Download or read book Natural Attenuation for Groundwater Remediation written by Commission on Geosciences, Environment, and Resources and published by National Academies Press. This book was released on 2000-08-31 with total page 289 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the past decade, officials responsible for clean-up of contaminated groundwater have increasingly turned to natural attenuation-essentially allowing naturally occurring processes to reduce the toxic potential of contaminants-versus engineered solutions. This saves both money and headaches. To the people in surrounding communities, though, it can appear that clean-up officials are simply walking away from contaminated sites. When is natural attenuation the appropriate approach to a clean-up? This book presents the consensus of a diverse committee, informed by the views of researchers, regulators, and community activists. The committee reviews the likely effectiveness of natural attenuation with different classes of contaminants-and describes how to evaluate the "footprints" of natural attenuation at a site to determine whether natural processes will provide adequate clean-up. Included are recommendations for regulatory change. The committee emphasizes the importance of the public's belief and attitudes toward remediation and provides guidance on involving community stakeholders throughout the clean-up process. The book explores how contamination occurs, explaining concepts and terms, and includes case studies from the Hanford nuclear site, military bases, as well as other sites. It provides historical background and important data on clean-up processes and goes on to offer critical reviews of 14 published protocols for evaluating natural attenuation.