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Anaerobic Biological Dechlorination Of Tetrachloroethene With Complex Electron Donors
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Book Synopsis Anaerobic Biological Dechlorination of Tetrachloroethene with Complex Electron Donors by : Rishi Ram Baral
Download or read book Anaerobic Biological Dechlorination of Tetrachloroethene with Complex Electron Donors written by Rishi Ram Baral and published by . This book was released on 2000 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: Effectiveness of complex organic electron donors with respect to PCE dechlorination is investigated.
Book Synopsis Biological Dechlorination of Tetrachloroethene Under Anaerobic Conditions by : Thomas Dominic DiStefano
Download or read book Biological Dechlorination of Tetrachloroethene Under Anaerobic Conditions written by Thomas Dominic DiStefano and published by . This book was released on 1992 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis The Effect of 1,1,1-trichloroethane Or Chloroform on Anaerobic Dechlorination of Tetrachloroethene and Trichloroethene by : Karrie Anne Dudiak
Download or read book The Effect of 1,1,1-trichloroethane Or Chloroform on Anaerobic Dechlorination of Tetrachloroethene and Trichloroethene written by Karrie Anne Dudiak and published by . This book was released on 1998 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The primary goal of this research was to determine the ability of a culture taken from a bulk-aerobic fluidized-bed reactor (FBR) to dechlorinate tetrachloroethylene (PCE) under anaerobic conditions when provided with an electron donor and nutrient source. Subsequent objectives examined the effects of toluene, 1,1,1-trichloroethane (TCA), and chloroform (CF) on the dechlorination of PCE."--Abstract.
Book Synopsis Bioremediation of Chlorinated Solvents by : Robert E. Hinchee
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.
Book Synopsis Effect of Electron Donors on the Reductive Dechlorination of Trichlorofluoroethylene in Anaerobic Microcosms and in Situ Push-pull Tests by : Erika N. Louie
Download or read book Effect of Electron Donors on the Reductive Dechlorination of Trichlorofluoroethylene in Anaerobic Microcosms and in Situ Push-pull Tests written by Erika N. Louie and published by . This book was released on 1999 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research focuses on the anaerobic transformation of trichloroethylene (TCE) that is occurring in the subsurface of the Evanite site in Corvallis, OR. Two anaerobic studies were conducted to investigate the effects of microbial communities in the presence of different electron donors during the anaerobic degradation of trichlorofluoroethylene (TCFE), and TCE. The first study was conducted in the groundwater microcosm bottles, filled with groundwater collected from the monitoring well 15 at the site. Because TCE was present in low concentrations in this well, TCFE was added to the microcosms as a surrogate compound that might be dehalogenated like TCE. Lactate, formate and hydrogen were evaluated as substrates for driving the anaerobic transformations. These substrates and products are potential electron donors to enhance the dechlorination of TCE and possibly TCFE. When injecting TCFE with one of the substrates in the microcosm bottles, a quick reduction of TCFE was observed to cis-dichlorofluoroethylene (cis-DCFE), and the transformation of the substrates to acetate. When TCFE and TCE were present as mixtures, a faster reduction of TCE to cis-DCE was observed compared to TCFE to cis-DCFE. The second study was an in-situ push-pull test at well15. Formate and TCFE were added to groundwater extracted from well 15. The amended groundwater was injected and extracted after a reaction time ranging from 3 to 5 hours. This study was conducted to determine the in-situ response to the addition of an electron donor to enhance the biotransformation of TCFE and TCE. During the push-pull test no transformation of formate to acetate was observed. Some TCFE was transformed to cis-DCFE. It is possible that another electron donor was present in the aquifer that lead TCE to transform to cis-DCE and furthermore to VC, and TCFE to cis-DCFE under reductive dechlorination conditions. These anaerobic systems involve the interaction of several reactions within the microbial population. Different transformations throughout the experimentation were an indication that the microbial population was active during the different stages of the study.
Book Synopsis Biological Dechlorination of Tetrachloroethene Under Anaerobic by : Thomas Dominic DiStefano
Download or read book Biological Dechlorination of Tetrachloroethene Under Anaerobic written by Thomas Dominic DiStefano and published by . This book was released on 1992 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Comparison of Alternative Hydrogen Donors for Anaerobic Reductive Dechlorination of Tetrachloroethene by : Donna Elaine Fennell
Download or read book Comparison of Alternative Hydrogen Donors for Anaerobic Reductive Dechlorination of Tetrachloroethene written by Donna Elaine Fennell and published by . This book was released on 1998 with total page 802 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Biological Degradation of Tetrachloroethylene in Methanogenic Conditions by : James M. Gossett
Download or read book Biological Degradation of Tetrachloroethylene in Methanogenic Conditions written by James M. Gossett and published by . This book was released on 1994 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: Research objective: investigate anaerobic biodegradation of perchloroethylene (PCE). Specific objectives: determine if the presence of PCE is necessary to sustain dechlorination of vinyl chloride (VC), delineate the role of hydrogen (H2) in PCE reductive dechlorination, investigate the ability of the high level PCE/methanol (MeOH) culture to utilize low levels of PCE, and determine the applicability of an Anaerobic Attached-film Expanded-bed (AAFEB) reactor to achieve PCE dechlorination. The investigators determined: by using a VC-fed culture unable to sustain ETH production, that the presence of PCE is required to sustain VC dechlorination, H2 acts as the electron donor directly used for the reductive dechlorination of PCE to ethene, the PCE/MeOH culture was able to use ppb levels of PCE due to the small requirement for electron donor (H2) by the culture, and that the loss of the dechlorinating biomass from the support matrix, and/or the inability of the culture to support PCE dechlorination at low concentrations, led to the failure of the AAFEB reactor system. Biodegradation, Tetrachloroethylene, Methanogenesis, Fixed-film reactors, Biological treatment, Chlorinated hydrocarbons.
Book Synopsis Proceedings of the Symposium on Natural Attenuation of Chlorinated Organics in Ground Water by :
Download or read book Proceedings of the Symposium on Natural Attenuation of Chlorinated Organics in Ground Water written by and published by DIANE Publishing. This book was released on 1996 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Water Pollution in Natural Porous Media at Different Scales by : L. Candela
Download or read book Water Pollution in Natural Porous Media at Different Scales written by L. Candela and published by IGME. This book was released on 2007 with total page 780 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Use of Vegetable Oil in Reductive Dechlorination of Tetrachloroethene by : Sin Chit To
Download or read book Use of Vegetable Oil in Reductive Dechlorination of Tetrachloroethene written by Sin Chit To and published by . This book was released on 2001 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reductive dechlorination is an effective bioremediation method for treating tetrachloroethene and its daughter compounds. Common techniques of stimulating reductive dechlorination involve the injection of costly, soluble electron donors into the contaminated plume. Vegetable oil is a cheaper alternative to such donors on a cost-per-mass basis, and may even be more economically implemented. This study applied microcosm studies to investigate the effectiveness of vegetable oil as an electron donor. Cultures fed with vegetable oil were observed to completely dechlorinate tetrachloroethene to ethene. Dechlorination by vegoil was also sustainable over a period of 140 days without the addition of nutrient amendments. Nevertheless, vegetable oil was found to ferment relatively quickly, leading to low donor efficiency. Biomass and acetate were the most significant products of vegoil-fed microcosms. Volatile fatty acids longer than 2 carbons rarely persisted. Since these acids can act as good secondary donors in the aqueous phase, their absence implies that the dechlorination zone does not extend very far from the vegoil phase. Inference from biomass measurements and dechlorination behavior hints that endogenous decay of large quantities of biomass could provide a stable source of electron donor. Perhaps a similar method of growing up a large pool of biomass for electron-donating purposes could be investigated in the future. Since acetate rarely ferments further to produce more hydrogen, and methanogenic biomass is fairly immobile, one good area of application for vegoil would be in bio-barriers. Interception of a contaminated plume by constructing biobarriers downstream reduces the need to maintain a large zone of treatment, although treatment times could be longer. For example, vegetable-oil-coated sand particles could be used to back-fill a trench to intercept and treat a plume consisting of dissolved chlorinated ethenes.
Book Synopsis Anaerobic Reductive Dechlorination of TCE and TCFE in TCE Contaminated Sediments by : Jae-Hyuk Lee
Download or read book Anaerobic Reductive Dechlorination of TCE and TCFE in TCE Contaminated Sediments written by Jae-Hyuk Lee and published by . This book was released on 2006 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research focused on the enhanced reductive dechlorination of trichloroethene (TCE) and its surrogate, trichlorofluoroethene (TCFE), using two bioremediation methods in anaerobic conditions. Two anaerobic bioremediation studies were conducted to investigate the effects of microbial communities in the presence of different electron acceptors and donors during anaerobic reductive dechlorination of TCE and TCFE. The first study was conducted in the groundwater microcosm bottles, filled with groundwater and sediments collected from Richmond site, CA. Parallel reductive dechlorination of TCE and TCFE was evaluated in the presence of fumarate and its product, succinate, while active reduction of high background concentrations of sulfate (2.5 mM) occurred. Because sulfate was assumed as a favorable electron acceptor during reductive dechlorination of chlorinated aliphatic hydrocarbons (CAHs), all microcosms receiving TCE and TCFE with substrates showed enhanced reductive dechlorination activity and even no substrate addition microcosms generated biotransformation products. From the electron mass balance calculations, more than 87.5% of electrons went to sulfate reduction and less than 10% of available electrons involved in dechlorination after sulfate reductions. After amending varying concentrations of sulfate (0 2.5 mM), no inhibition was found between reductive dechlorination of TCE and sulfate reduction. The result indicated that reductive dechlorination could be directly competed with sulfate reduction for available electrons. The second study investigated the effectiveness of in situ push-pull tests to evaluate bioaugmentation in physical aquifer models (PAMs) using dehalogenating strains to reductively dechlorinate TCE to ethene and TCFE to FE in the TCE contaminated sediments. Complete reduction of TCE to ethene occurred in less than 14 days with repeated additions of TCE (13.0 to 46.0 mg/L) and TCFE (15.0 mg/L) was completely transformed to FE in under 24 days. Increased rate and extent of dechlorination in the bioaugmented PAM compared to the nonaugmented control PAM indicated successful transport of the bioaugmented culture through the PAM. Similar transformation rates and time course of TCE and TCFE also indicated that TCFE was a bioprobe for reductive dechlorination of TCE. TCE and TCFE were transformed to cisdichloroethene (c-DCE) and cis-dichlorofluoroethene (c-DCFE) respectively at two of the three sampling ports after 50 days of incubation in the nonaugmented PAM indicating reductive dechlorination activity of indigenous microorganisms. The results showed that it is possible to increase the rate and extent of reductive dechlorination of TCE and TCFE by bioaugmentation and that push-pull tests are effective tools for detecting and quantifying these processes in situ. The third study focused on numerical modeling of the second study. The objectives of this study were (1) to evaluate a simplified method for estimating retardation factors for injected solutes and bioaugmented microorganisms using "pushpull" test injection phase breakthrough curves, (2) to identify whether bioaugmented microorganisms have kept the same transformation capacity of Evanite culture using Michaelis-Menten kinetics by the values provided by Yu et al. (2005) and to verify in situ rates of TCFE reductive dechlorination rates of push-pull tests by numerical modeling, and (3) to investigate a reasonable answer for the nonuniform recovery of ethene and FE during the activity test and the push-pull test. The bioaugmented microorganisms were effectively transported through Hanford sediment. The estimated retardation factor was 1.33. A numerical simulation predicted cell transport in the PAM as far as port 5. This was qualitatively confirmed by cell counts obtained during bioaugmentation but, cells were distributed nonuniformly. The transport test indicated that TCE and TCFE transport was relatively retarded compared to coinjected bromide tracer (retardation factors ranged from 1.33-1.62 for TCE and from 1.44-1.70 for TCFE). The modeling simulation of Michaelis-Menten kinetics for the activity test was well matched for reductive dechlorination rates for TCE and less dechlorinated ethenes using the previous published values of kmax and Ks of chlorinated ethenes by Yu et al. (2005); the model match indicated that the bioaugmented microorganisms kept the same transformation capacity as the original source, Evanite culture (Yu et al., 2005) over 4 months in the PAM. A numerical simulation resulted in the simple first order FE production rate of 1 day' using STOMP code (2002) and the value of FE production rate was in the range of the transformation rates of TCFE during the activity test. The bioaugmented PAM has caused slow loss of injected CAHs during the activity test and the push-pull test.
Book Synopsis Modeling Kinetics and Inhibition of Chloroethene Reductive Dechlorination in Mixed Culture by : Qi Meng
Download or read book Modeling Kinetics and Inhibition of Chloroethene Reductive Dechlorination in Mixed Culture written by Qi Meng and published by . This book was released on 2014 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chlorinated ethenes such as tetrachloroethene (PCE) and trichloloethene (TCE) are among the most prevalent contaminants in soil, sediments and groundwaters. Currently, Insitu bioremediation via anaerobic reductive dechlorination has become a widely used technology for groundwater contaminated with chlorinated ethenes. To better understand the reductive dechlorination remediation process and the inter-relationships among the complex microbial communities that comprise it, a comprehensive biokinetic model was recently developed at Cornell University by Gretchen Heavner, a modification of an earlier Cornell model developed by Donna Fennell. The Heavner model uses specific biomasses based on quantitative PCR-based population data, and under some conditions can accurately predict kinetics of dechlorination, fermentation of electron donors, and competition for electron donors between dechlorinators and methanogens, and generation of methane. However, the platform used to run the model - STELLA® (High Performance Systems) - is cumbersome for simulation of long time-spans, limiting the model's utility. Furthermore, the model uses an empirical, "mRNA-tuning" technique to improve data fits at high PCE-loadings, which makes the model descriptive, rather than predictive, in such cases. Additionally, electron donor fermentation is not predicted well at high electron-donor feeding rates. The overall purpose of this thesis research was to address some of the limitations of the Heavner model. The STELLA® model was successfully converted to run in MATLAB® using Runge-Kutta 4th-order integration. The model fits at high-PCE and high electron-donor loadings were improved by utilizing the inhibitory effects of high PCE on dechlorination and methanogenesis, and by postulating additional pathways of butyrate's fermentation and acetate's hydrogenation to storage products. Model simulations indicate that by adding 2nd-order Haldane inhibition instead of mRNA tuning, the model revised in this thesis research predicts the dechlorination, methanogenesis and donor fermentation well over a broad range of PCE feeding rates. Moreover, when simulating donor fermentation at high-PCE-loadings, butyrate's fermentations and acetate's hydrogenation to storage products must be considered to obtain a mass balance between butyrate consumption and product formation.
Book Synopsis Organohalide-Respiring Bacteria by : Lorenz Adrian
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.
Book Synopsis Innovative Approaches to the On-Site Assessment and Remediation of Contaminated Sites by : Danny Reible
Download or read book Innovative Approaches to the On-Site Assessment and Remediation of Contaminated Sites written by Danny Reible and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: 2 DANNY D. REIBLEI AND KATERINA DEMNEROVA 1 Hazardous Substance Research Center/South and Southwest, Louisiana State University, Baton Rouge, LA 70803 2 Department of Biochemistry and Microbiology, Institute of Chemical Technology, Prague, Czech Republic On May 24, 2001, a total of 102 students and lecturers participated in an Advanced Study Institute (ASI) sponsored by the North Atlantic Treaty Organization (NATO) under our direction. The Institute was focused on in situ and onsite management of contaminated sites. The objective of the Institute was to balance state of the art science with techniques for field application of a variety of technologies for in situ assessment and remediation of contaminated sites. Many of the lecturers were drawn from the ranks of the Hazardous Substance Research Centers, multi-university consortia that have been funded by the US Environmental Protection Agency to conduct research and technology transfer designed to promote risk-based management and control of hazardous substances for the nation. The Centers have made special contributions to the areas of in situ and onsite assessment and remediation of contaminated sites. Such approaches have the potential for being significantly less expensive than other assessment and remediation approaches while maintaining accuracy and effectiveness. Cost-effective remedial and management approaches that are also effective in minimizing exposure and risk to human health and the environment are a critical need throughout the world but particularly in Eastern Europe and the former Soviet Union where resources that can be devoted to environmental cleanup are especially limited.
Book Synopsis Reductive Dechlorination of Tetrachloroethene in Polluted Aquifer Microcosms and Isolation of Anaerobic Bacteria from a Tetrachloroethene-dechlorinating Enrichment by : Christopher D. Carlson
Download or read book Reductive Dechlorination of Tetrachloroethene in Polluted Aquifer Microcosms and Isolation of Anaerobic Bacteria from a Tetrachloroethene-dechlorinating Enrichment written by Christopher D. Carlson and published by . This book was released on 1997 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Bioaugmentation for Groundwater Remediation by : Hans F. Stroo
Download or read book Bioaugmentation for Groundwater Remediation written by Hans F. Stroo and published by Springer Science & Business Media. This book was released on 2012-10-02 with total page 421 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume provides a review of the past 10 to 15 years of intensive research, development and demonstrations that have been on the forefront of developing bioaugmentation into a viable remedial technology. This volume provides both a primer on the basic microbial processes involved in bioaugmentation, as well as a thorough summary of the methodology for implementing the technology. This reference volume will serve as a valuable resource for environmental remediation professionals who seek to understand, evaluate, and implement bioaugmentation.
