Download or read book A Field Experiment Evaluating Enhanced Reductive Dechlorination of Chlorinated Solvents in Groundwater written by Eric Rodriguez and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chlorinated Solvent Source Zone Remediation written by Bernard H. Kueper and published by Springer Science & Business. This book was released on 2014-04-22 with total page 759 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this book is to help engineers and scientists better understand dense nonaqueous phase liquid (DNAPL) contamination of groundwater and the methods and technology used for characterization and remediation. Remediation of DNAPL source zones is very difficult and controversial and must be based on state-of-the-art knowledge of the behavior (transport and fate) of nonaqueous phase liquids in the subsurface and site specific geology, chemistry and hydrology. This volume is focused on the characterization and remediation of nonaqueous phase chlorinated solvents and it is hoped that mid-level engineers and scientists will find this book helpful in understanding the current state-of-practice of DNAPL source zone management and remediation.
Download or read book Reductive Anaerobic Biological In Situ Treatment Technology Treatability Testing written by and published by . This book was released on 2002 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Enhanced biological reductive dechlorination (EBRD) shows a great deal of promise for efficiently treating groundwater contaminated with chlorinated solvents, but demonstration sites around the country were reporting mixed results. Because individual demonstrations commonly used dissimilar methods, the limitations of the technology were not clear and its applicability at any given site was unknown. As a result, the Environmental Security Technology Certification Program (ESTOP) invested in the development of a standardized protocol to test the technology's effectiveness at any site. A draft protocol was developed that included microcosm and field-testing and an extensive array of sampling and monitoring. Once developed, the draft protocol was applied at four sites to evaluate its overall effectiveness. Data generated at the four sites was used to refine the protocol by eliminating less valuable components while maintaining a testing methodology that provides scientifically defensible data that would satisfy the regulatory community at a reasonable cost. Microcosm testing was used to evaluate the performance of a suite of electron donors, which included yeast extract, lactate, butyrate, benzoic add, propionic add, and acetic add. The testing examined the rate, onset, and extent of dechlorination as well as donor fermentation pathways. Microcosm testing data revealed an apparently heterogeneous distribution of dechlorinating organisms within Individual sites, and that most electron donors will eventually yield the same dechlorination endpoint, though the onset and rate of dechlorination may differ significantly. The electron donor showing the most rapid and complete dechlorination in microcosm studies (usually butyrate) was used in the four 6-month field demonstrations.
Download or read book Anaerobic Degradation of Chlorinated Solvents written by Victor Magar and published by . This book was released on 2001 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: The symposium included 600 presentations in 50 sessions on bioremediation and supporting technologies used for a wide range of contaminants already in, or poised to invade, soil, groundwater, and sediment. Three hundred and fifty-two papers were selected and organized into ten volumes. Volume seven's articles examine the use of enhanced anaerobic biotransformation processes for treatment of chlorinated solvents in soil and groundwater. Electron donors used to stimulate reductive dechlorination processes in lab- and field-scale demonstrations are also presented. Articles average eight pages, and contain abstracts and references. Annotation copyrighted by Book News Inc., Portland, OR.
Download or read book Evaluation of Electron Donor Materials Used to Create Subsurface Permeable Reactive Barriers for Enhanced Reductive Dechlorination of Chlorinated Ethenes written by Elizabeth S. Semkiw and published by . This book was released on 2008 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chlorinated ethenes (CEs) are widespread ground water contaminants, apparently due to their extensive migration from numerous contamination source points. In this study, a long-term field investigation and aquifer microcosm experiments were combined to evaluate the effectiveness of electron donor materials used to create and maintain subsurface permeable reactive barriers (PRBs) for the enhanced in-situ biodegradation of CEs. The laboratory component includes the first side-by-side comparison of electron donor materials dairy whey, lactate syrup, and Hydrogen Release Compound [Registered] (HRC), in which dechlorination rates, fermentation product distributions, and H[subscript 2] production were monitored as measures of substrate efficiency. Field study allowed the first investigation of the long-term efficacy of a full-scale (~300 ft.) when PRB designed to dechlorinate high concentrations of CEs (10[superscript 2]-10[superscript 3] [micro]g/L) migrating from a source zone. The effects of altering substrate loading volume, loading frequency, and injection method on CE distributions are examined. In donor-amended aquifer microcosms, substrate fermentation to slow-degrading organic acids maintained low H[subscript 2] partial pressures that, as previous studies suggest, may give competitive advantage to dechlorinators over hydrogenotrophic methanogens. Whey-amended and lactate-amended microcosms exhibited faster complete dechlorination. Whey-amended microcosms contained the highest percentage of organic acid carbon upon complete dechlorination. Whey's efficiency improved in microcosms prepared with whey-treatment-zone sediment and ground water, due apparently to the growth of native dechlorinators (e.g. Dehalococcoides) and microbial adaptation to whey within the PRB. In the field study, CEs decreased to low ([less than or equal to]10 [micro]g/L) or undetected levels within the PRB, while trichloroethene and cis-dichloroethene treatment-period average concentrations decreased significantly at downgradient points. Improved and sustained dechlorination was observed following injection of 300 kg whey, as a 750 mg/L slurry, with the use of extraction-injection loops. Results indicate whey loading values of 0.2 kg/m[superscript 3] are appropriate under sufficiently reducing conditions. Comparison of whey fermentation product, chemical oxygen demand (COD), and CE trends indicate whey's lifetime was 4-5 months. Based on the longevity of whey and its 2006 average market price, the estimated material cost of a 300-ft whey PRB is $700/year. Cost comparison, based on determinations of carbon flow in donor-amended microcosms, suggests whey is by far the more cost-efficient PRB material.
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.
Download or read book Groundwater and Soil Cleanup written by National Research Council and published by National Academies Press. This book was released on 1999-11-21 with total page 301 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a comprehensive, up-to-date review of technologies for cleaning up contaminants in groundwater and soil. It provides a special focus on three classes of contaminants that have proven very difficult to treat once released to the subsurface: metals, radionuclides, and dense nonaqueous-phase liquids such as chlorinated solvents. Groundwater and Soil Cleanup was commissioned by the Department of Energy (DOE) as part of its program to clean up contamination in the nuclear weapons production complex. In addition to a review of remediation technologies, the book describes new trends in regulation of contaminated sites and assesses DOE's program for developing new subsurface cleanup technologies.
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.
Download or read book Assessment of Potential for Natural Attenuation of Chlorinated Ethenes and Ethanes in Ground Water at a Petrochemical Reclamation Site Harris County Texas written by Glenn F. Huff and published by . This book was released on 2000 with total page 36 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 Enhanced Reductive Dechlorination of TCE in a Basalt Aquifer written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A field evaluation of enhanced reductive dechlorination of trichloroethene (TCE) in ground water has been in progress since November 1998 to determine whether in situ biodegradation can be significantly enhanced through the addition of an electron donor (lactate). An in situ treatment cell was established in the residual source area of a large TCE plume in a fractured basalt aquifer utilizing continuous ground water extraction approximately 150 meters downgradient of the injection location. After a 1-month tracer test and baseline sampling period, the pulsed injection of lactate was begun. Ground water samples were collected from 11 sampling points on a biweekly basis and in situ water quality parameters were recorded every 4 hours at two locations. Within 2 weeks after the initial lactate injection, dissolved oxygen and redox potential were observed to decrease substantially at all sampling locations within 40 m of the injection well. Decreases in nitrate and sulfate concentrations were also observed. Both quantitative in situ rate estimation methods and qualitative measures such as changes in redox conditions, decreases in chlorine number, and changes in biomass indicator parameters are being used throughout the test to evaluate the extent to which biodegradation of TCE is enhanced.
Download or read book Enhanced Anaerobic Dechlorination of Chlorinated Solvents in the Capillary Fringe written by Sebastien Roupen Kaskassian and published by . This book was released on 2002 with total page 394 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bioventing under anaerobic reductive conditions has been presented as a potential bioremediation technology for dealing with highly chlorinated compounds present in the capillary fringe of a contaminated soil. Anaerobic reductive bioventing is similar to aerobic bioventing, providing the gas injected is free of oxygen and contains an electron donor, here hydrogen. The concept of bioventing is reported to be cost effective because of the in-situ solution it provides. Tetrachloroethylene (PCE) typically degrades under anaerobic, reductive conditions to Vinyl Chloride (VC), which can then be readily oxidized to environmentally benign products. In this study, enhanced anaerobic degradation of PCE in the unsaturated zone of the soil was simulated in soil microcosms. Four 15 cm high and 8 cm in diameter reactors were filled with a contaminated soil sampled at an Air Force base site. Each reactor allowed for a different set of conditions in components concentration in the gas feed. The work focused on optimizing the injection gas composition, monitoring electron donor delivery and utilization, and evaluating the treatment performance of PCE. Only one microcosm, fed with 0.5 % of hydrogen and 0.5 % of carbon dioxide, showed dechlorination of PCE into Trichloroethylene (TCE) and Cis-Dichloroethylene (Cis-DCE). This microcosm completely consumed hydrogen and produced little methane, thus proving that the feeding conditions favored dechlorinators over methanogenes. PCE sequential dehalogenation did not proceed further than Cis-DCE but the total quantity of intermediates produced accounted for more than 40 % of the PCE removed in that dechlorinating microcosm. In the other microcosms, PCE removal was mainly due to adsorption of PCE onto the soil organic matter. Adding biomass to the microcosm or increasing the gas retention time did not result in significant improvements of the microcosm dechlorinating activity. Pre-existing soil contaminants, mainly hydrocarbons, were not responsible for the lack of dechlorination. Gas feeding concentrations were the only parameters proved to trigger PCE sequential dechlorination since they helped maintaining reducing conditions. This study was useful to assess the potential for dechlorination of highly chlorinated compounds in a specific soil sample and to optimize the feed conditions to be applied when testing anaerobic bioventing in-situ.
Download or read book Enhanced Reductive Dechlorination in Edible Oil Barriers written by Cameron Michael Long and published by . This book was released on 2004 with total page 79 pages. Available in PDF, EPUB and Kindle. Book excerpt: Keywords: chlorinated, Dechlorination, PCE, solvents.
Download or read book Symposium on Natural Attenuation of Chlorinated Organics in Groundwater written by and published by . This book was released on 1996 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Numerical Investigation of Metabolic Reductive Dechlorination in DNAPL Source Zones written by John Anthony Christ and published by . This book was released on 2005 with total page 632 pages. Available in PDF, EPUB and Kindle. Book excerpt: Among the most intractable environmental remediation problems are those involving the release of dense non-aqueous phase liquids (DNAPLs), such as chlorinated solvents, to the subsurface. Research efforts have focused on the use of numerical models to investigate reductions in contaminant concentrations due to partial mass removal and improvements in the performance of complementary source zone remediation technologies. Previous numerical investigations, however, have been limited to two-dimensional systems. Furthermore, a lack of models capable of simulating the most promising complementary technology, metabolic reductive dechlorination, has limited its application. This work developed and applied compositional multiphase numerical simulators to examine the influence of dimensionality (two-dimensions versus three-dimensions) on DNAPL source zone simulations and to investigate the benefits of stimulating metabolic reductive dechlorination at a chlorinated ethene-DNAPL contaminated site. Results from the dimensionality investigation showed that the simulation of DNAPL migration, entrapment, and dissolution in two dimensions provided reasonable approximations to the behavior simulated in three dimensions. Commonly employed saturation distribution and mass recovery metrics were approximately equivalent. Flux- averaged concentrations simulated in two dimensions, however, tended to be three to four times higher than those simulated in three dimensions. This difference was attributed to dilution at the down gradient boundary. An alternative metric, mass flux reduction, however, yielded better agreement.
Download or read book Enhanced Reductive Dechlorination of Chlorinated Aliphatic Hydrocarbons written by William J.. Hickey and published by . This book was released on 2008 with total page 16 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.
