Download or read book Stable Isotopic Investigations of In situ Bioremediation of Chlorinated Organic Solvents written by and published by . This book was released on 1999 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this project was to investigate the potential applications of stable isotope ratio measurements in characterization of the source terms, the transport, and the fate of chlorinated solvents in groundwater aquifers. The approach to this research was threefold: to develop methods for the sampling and isotopic analysis of chlorinated solvents in groundwaters; to perform laboratory experiments to measure equilibrium and kinetic isotope effects associated with biological and physical transformation processes of chlorinated solvents; and to perform field investigations at well-characterized, contaminated aquifer sites to demonstrate the applicability of the isotopic approach in real-world situations. New methods were developed for the extraction and isotopic analysis of chlorinated solvents in water samples. The new methods were applied to a series of laboratory experiments assessing the isotope effects associated with biological and physical transformation processes. The authors found that a large kinetic isotope effect was caused by microbial degradation of chlorinated solvents, under both aerobic and anaerobic conditions. The evaporation of chlorinated solvents also caused a large isotope effect, but in that case the carbon isotopic fractionation was in the reverse sense. Isotopic fractionation associated with adsorption and chemical exchange of chlorinated solvents was negligible. The authors performed field investigations at five present and former industrial sites undergoing various stages of remediation. These investigations were collaborative with Lockeed-Martin Energy Systems, Inc., and ENSR, Inc., the companies responsible for the remedial work at these sites. Application of the new sampling and analytical methods at these sites showed that stable isotopic measurements yield powerful insights into underground processes. In particular, they found positive evidence for in-situ microbial degradation of chlorinated solvents at all five sites, evidence for volatilization of chlorinated solvents at three sites, and evidence for multiple sources of chlorinated solvents at two sites. At a site where six-phase heating was applied, they found evidence for increased solubilization of pure phase chlorinated solvents during heating. The general conclusion of the field investigations is that stable isotope measurements should become an essential component in site characterization and remediation of sites contaminated with chlorinated solvents.
Download or read book Stable Isotopic Investigations of in Situ Bioremediation of Chlorinated Organic Solvents 1997 Annual Progress Report written by and published by . This book was released on 1997 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt: The author has made significant progress in developing innovative methods for investigating the mechanism and extent of in situ bioremediation of chlorinated organic solvents. These methods use precise isotopic ratio measurements of chlorine and carbon in reactant and product species in laboratory experiments and in materials from field demonstration sites. Specific tasks completed during FY 1997 include: (1) refinement and publication of a new analytical method for precise determination of chlorine and carbon isotope ratios in chlorinated volatile organic compounds; (2) laboratory experiments involving biological degradation of chlorinated solvents in liquid cultures and soil columns; and (3) use of chlorine and carbon isotope ratios to investigate natural attenuation of trichloroethene at the Paducah Gaseous Diffusion Plant. This work can have immediate impact because it will provide the fundamental basis for a new and cost-effective means of evaluating and monitoring the effectiveness of in situ bioremediation schemes for chlorinated organic solvents in soils, vadose horizons, and groundwater plumes.
Download or read book Stable Isotopic Investigations of In situ Bioremediation of Chlorinated Organic Solvents 1998 Annual Progress Report written by and published by . This book was released on 1998 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contamination of soils and groundwaters with chlorinated aliphatic hydrocarbons (CAHs) is one of the most serious environmental problems in the DOE system and in the nation at large. These compounds are designated as priority pollutants by the US Environmental Protection Agency (EPA) and are known or suspected to be carcinogenic or mutagenic in humans. These compounds are readily transported by groundwater and are not reduced to acceptable concentrations for human consumption by most municipal water supply treatments; thus the compounds represent a significant hazard to a large portion of the human population. In situ bioremediation is an emerging technology that shows great promise for mitigation of CAH contamination at many sites. One of the most severe limitations of in-situ bioremediation is the difficulty of proving when it is working at a given site. The concentrations of CAHs and their degradation products in plumes may be difficult to relate to the efficiency of the remediation process because of dilution effects, but this problem is mitigated to a large extent by measuring isotope ratios. If there is a significant isotopic fractionation between CAHs and derivative chlorine-bearing products, then the fraction of CAH that is dechlorinated can be inferred from the 37Cl/35Cl and 13C/12C isotope ratios of the residual CAH. It is important to point out that there is currently no published information available on the magnitude of chlorine and carbon isotopic fractionation associated with biological degradation of CAHs. The authors plan to help eliminate this important gap in the knowledge with the work being performed here. This work is relevant to EMSP goals because it will provide a new and cost-effective means of evaluating and monitoring the effectiveness of in-situ bioremediation. It will employ newly developed techniques to characterize isotopic fractionation (of chlorine and carbon) associated with biotic and abiotic degradation of CAHs in laboratory microcosms. These techniques and the data acquired by using them in laboratory studies will form the fundamental basis for quantitative assessment of the mechanisms, rates, and efficiencies of various in-situ bioremediation schemes for CAHs. This report summarizes work as of 21 months into a 36-month project. First, the author has developed methods for precise measurement of stable carbon and chlorine isotope ratios of micromolar amounts of CAHs. He has also developed methods for quantitative extraction of CAHs from water and air. He has applied these methods in laboratory experiments, to investigate isotopic fractionation caused by microbial degradation and by abiotic processes such as evaporation and chemical reduction. He has also applied these methods to field investigations of contaminated groundwater aquifers at the Paducah Gaseous Diffusion Plant, Kentucky and at several manufacturing plants in the Chicago and Kansas City metropolitan areas. Results of much of this work have already been incorporated into four manuscripts that have been published, accepted for publication, or are in review.
Download or read book Engineered Approaches to in Situ Bioremediation of Chlorinated Solvents written by and published by DIANE Publishing. This book was released on 2000 with total page 152 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 Engineered Approaches to In Situ Bioremediation of Chlorinated Solvents Fundamentals and Field Applications written by and published by . This book was released on 2000 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: Halogenated volatile organic compounds, including chlorinated solvents, are the most frequently-occurring type of soil and groundwater contaminant at Superfund and other hazardous waste sites in the United States. The U.S. Environmental Protection Agency (EPA) estimates that, over the next several decades, site owners will spend billions of dollars to clean up these sites. New technologies that are less costly and more effective are needed to accomplish hazardous waste site remediation. As these new and innovative technologies are being developed and used, site managers require information on how they work, their performance to date, and how to evaluate their application at a particular site. This report provides an overview of the fundamentals and field applications of in situ bioremediation to remediate chlorinated solvents in contaminated soil and groundwater. In situ treatment is increasingly being selected to remediate sites because it is usually less expensive, and does not require waste extraction or excavation. In addition, in situ bioremediation is more publicly acceptable than above-ground technologies because it relies on natural processes to treat contaminants. This document presents information at a level of detail intended to familiarize federal and state project managers, permit writers, technology users, and contractors with in situ bioremediation. The report describes how chlorinated solvents are degraded, how to enhance the process by the addition of various materials and chemicals, design configurations, and the typical steps taken to evaluate technology feasibility at a specific site. It also includes a list of technology vendors and nine case studies of field applications. It is important to note that this report cannot be used as the sole basis for determining this technology's applicability to a specific site.
Download or read book Environmental Investigation and Remediation written by Thomas K.G. Mohr and published by CRC Press. This book was released on 2016-04-19 with total page 552 pages. Available in PDF, EPUB and Kindle. Book excerpt: A ubiquitous, largely overlooked groundwater contaminant, 1,4-dioxane escaped notice by almost everyone until the late 1990s. While some dismissed 1,4-dioxane because it was not regulated, others were concerned and required testing and remediation at sites they oversaw. Drawing years of 1,4-dioxane research into a convenient resource, Environmental
Download or read book Engineered Approaches for in Situ Bioremediation of Chlorinated Solvent Contamination written by Andrea Leeson and published by . This book was released on 1999 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sites contaminated with chlorinated compounds pose health risks and are challenging and often expensive to treat in the field. This volume brings together the most up-to-date laboratory findings and the latest full-scale results from bioremediation efforts at actual field sites. Engineering approaches discussed include biobarriers, cometabolism, bioaugmentation, in situ oxidation, Fenton's Reagent, in situ bioremediation, and more.
Download or read book Environmental Forensics written by Robert D. Morrison and published by Elsevier. This book was released on 2010-08-04 with total page 579 pages. Available in PDF, EPUB and Kindle. Book excerpt: Environmental forensics is the application of scientific techniques for the purpose of identifying the source and age of a contaminant. Over the past several years, this study has been expanding as a course of study in academia, government and commercial markets. The US Environmental Protection Agency (EPA), Federal Bureau of Investigation (FBI), and Federal Emergency Management Agency (FEMA) are among the governmental agencies that utilize the study of environmental forensics to ensure national security and to ensure that companies are complying with standards. Even the International Network for Environmental Compliance and Enforcement (INECE), a group supported by the European Commission and the World Bank, utilizes the study of environmental forensics as it applies to terror threats.This title is a hands-on guide for environmental scientists, engineers, consultants and industrial scientists to identify the origin and age of a contaminant in the environment and the issues involved in the process. An expansion of the authors' first title with Academic Press, Introduction to Environmental Forensics, this is a state-of-the-art reference for those exploring the scientific techniques available. - Up-to-date compendium for referencing forensic techniques unique to particular contaminants. - International scientific unit system - Contributors from around the world providing international examples and case studies.
Download or read book Stable Isotope Geochemistry written by Jochen Hoefs and published by Springer Nature. This book was released on 2021-10-08 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt: This classic textbook is an introduction to the systematics and the use of stable isotopes in geosciences. It is subdivided into three parts: i) theoretical and experimental principles, ii) fractionation processes of light and heavy elements, iii) the natural variations of geologically important reservoirs. Since the publication of the previous edition improvements in multi-collector ICP mass-spectrometry have increased the ability to measure isotope ratios with very high precision for many elements of the periodic table. The amount of published data has increased tremendously in the last years; thus, conclusions based on a limited database are now better constrained. In this new edition, therefore, 47 elements with resolvable natural variations in isotope composition are discussed. This increase of elements, together with advances in the calculation of equilibrium isotope fractionation using ab initio methods, has led to an unbelievable rise of publications, making substantial major revisions and extensions of the last edition necessary. Many new references have been added, which enable quick access to recent literature.
Download or read book Methodologies for Evaluating In situ Bioremediation of Chlorinated Solvents written by and published by . This book was released on 1992 with total page 100 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 In situ Bioremediation of Chlorinated Solvents A Review written by and published by . This book was released on 1993 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: This review focuses on the in-situ bioremediation of chlorinated organic solvents. This group of compounds is one of the most widespread contaminant classes and one of the most troublesome to remediate. They are found nationwide in municipal and industrial waste waters, landfills and landfill leachates, industrial sludges, waste disposal sited, and groundwaters. Chlorinated alkanes and alkenes, such as trichloroethane (TCA) and trichloroethylene (TCE), are used as dry cleaning fluids, refrigerants, degreasing agents, solvents, and in the the production of decaffinated coffee. The review will include a discussion of laboratory-scale research, some field application considerations, and a review of a full-scale remediation study.
Download or read book In Situ Bioremediation written by Bruce E. Rittmann and published by Taylor & Francis. This book was released on 1994-12-31 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: This critical review of the status of in situ bioremediation, which is used to clean up contaminated groundwater aquifers and surface soils, has been organized according to possibilities and restrictions. Possibilities are based on present knowledge and indicate that in situ bioremediation can achieve decontamination of aquifers and soils. Restrictions encompass the scientific, engineering, legal, and other questions that stand in the way of successful development and application of in situ bioremediation. Although much has been written about bioremediation, this critical review is unique because it is comprehensive, critical, and integrated. This situation was no accident; the organization of the authorship team and the report's contents were designed to achieve each of the three attributes. Combining a good plan, outstanding individuals contributing, and an incredible amount of work, they created a critical review that defines the technical and non-technical issues that will determine how much of an impact in situ bioremediation makes on solving the world's challenges for cleanup of our legacy of improperly disposed of materials. Readers of this review will find the issues identified and connected. They will have a solid foundation for research, application, or evaluation of in situ bioremediation in the future.
Download or read book Methodologies for Evaluating In situ Bioremediation of Chlorinated Solvents written by and published by . This book was released on 1993 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book ENGINEERED APPROACHES TO IN SITU BIOREMEDIATION OF CHLORINATED SOLVENTS FUNDAMENTALS AND FIELD APPLICATIONS U S ENVIRONMENTAL PROTECTIO written by United States. Environmental Protection Agency and published by . This book was released on 2000* with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book In Situ Bioremediation of Chlorinated Ethene written by Interstate Technology and Regulation Council. Bioremediation of Dense Nonaqueous Phase Liquids (Bio DNAPL) Team and published by . This book was released on 2008 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt:
