Download or read book Verification of Biodegradation Delineation of Biodegradation Mechanisms and Differentiation of Sources of Chlorinated Contaminants Using Compound Specific Isotope Analysis written by Michelle Marie Grace Chartrand and published by . This book was released on 2007 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this thesis was to investigate the use of compound specific isotope analysis (CSIA) in contaminant hydrogeology by addressing four specific goals. First, carbon isotope (delta13C) measurements of trichlorethene (TCE), and its degradation products cis-1,2-dichloroethene (cDCE) and vinyl chloride (VC) from samples collected from a fractured bedrock field site were able to conclusively demonstrate that biodegradation was occurring, despite fluctuating concentration profiles of these compounds due to ongoing TCE dissolution and variable hydraulic gradients.Next, delta13C values were measured for aerobic cDCE and VC biodegradation. For the aerobic VC degrading microorganisms Mycobacterium sp. strains JS60, JS61 and JS614, and Nocardioides sp. strain 614, the first step in the biodegradation pathway involved a monooxygenase enzyme, which oxidized VC to chlorooxirane, and the measured enrichment factors ranged between -8.2 +/- 0.1 to --7.0 +/- 0.3 ‰. Larger fractionation was measured during aerobic cDCE biodegradation by Polaromonas sp. strain JS666 (-17.4 +/- 2.4 to --22.4 +/- 0.8 ‰). KIEs calculated from the measured enrichment factors suggests that the initial degradation step in the aerobic cDCE biodegradation pathway is not consistent with an initial attack on the carbon double bond by a monooxygenase enzyme to form an epoxide, as was observed for VC aerobic biodegradation.Third, a method was developed to measure the hydrogen isotope (delta 2H) values for chlorinated compounds. After 71 1,2-dichloroethane (1,2-DCA) delta2H measurements were obtained, the reproducibility of the modified system had degraded outside of acceptable analytical uncertainty. Combined delta2H and delta13C values of 1,2-DCA demonstrated that dual parameter isotopic measurements can distinguish between different contaminant sources, and may provide additional constraints on degradation pathways and contaminant remediation.Finally, a CSIA method was developed to analyze hexachlorocyclohexane (HCH) isomers. A range of delta13C values were obtained for alpha- and gamma-HCH from both pure product standards and technical grade HCH mixtures, demonstrating that CSIA has the potential to distinguish between different HCH sources. Further, delta13C analysis of HCH isomers at a contaminated field site may provide two additional lines of evidence that biodegradation of HCH isomers was occurring.
Download or read book A Guide for Assessing Biodegradation and Source Identification of Organic Ground Water Contaminants Using Compound Specific Isotope Analysis CSIA written by and published by . This book was released on 2008 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Compound specific Stable Isotope Analysis written by Maik A Jochmann and published by Royal Society of Chemistry. This book was released on 2015-11-09 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of Compound-specific Stable Isotope Analysis (CSIA) is increasing in many areas of science and technology for source allocation, authentication, and characterization of transformation reactions. Until now, there have been no textbooks available for students with an analytical chemical background or basic introductory books emphasising the instrumentation and theory. This book is the first to focus solely on stable isotope analysis of individual compounds in sometimes complex mixtures. It acts as both a lecture companion for students and a consultant for advanced scientists in fields including forensic and environmental science. The book starts with a brief history of the field before going on to explain stable isotopes from scratch. The different ways to express isotope abundances are introduced together with isotope effects and isotopic fractionation. A detailed account of the required technical equipment and general procedures for CSIA is provided. This includes sections on derivatization and the use of microextraction techniques in GC-IRMS. The very important topic of referencing and calibration in CSIA is clearly described. This differs from approaches used in quantitative analysis and is often difficult for the newcomer to comprehend. Examples of successful applications of CSIA in food authenticity, forensics, archaeology, doping control, environmental science, and extraterrestrial materials are included. Applications in isotope data treatment and presentation are also discussed and emphasis is placed on the general conclusions that can be drawn from the uses of CSIA. Further instrumental developments in the field are highlighted and selected experiments are introduced that may act as a basis for a short practical course at graduate level.
Download or read book Assessing Mechanisms of Isotopic Fractionation During Petroleum Hydrocarbon Biodegradation written by Silvia Alissa Mancini and published by . This book was released on 2007 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, mechanisms of carbon and hydrogen isotopic fractionation were investigated during biodegradation of petroleum hydrocarbons, benzene and toluene, in order to evaluate the potential to use Compound Specific Isotope Analysis (CSIA) to assess in situ biodegradation under various field conditions. Variation in carbon and hydrogen enrichment factors, determined using a Rayleigh model, was observed for benzene degradation under different terminal electron accepting processes in enrichment cultures derived from three field sites. This variation was controlled by different biodegradation pathways for the nitrate-reducing cultures, and the methanogenic and sulfate-reducing cultures, as determined by a two-element isotopic approach comparing delta 13C and delta2H values between degradation experiments. Significant differences in carbon and hydrogen enrichment factors were also observed in Pseudomonas putida mt-2 cultures grown under low and high iron concentrations during aerobic toluene biodegradation. These differences were related to changes in the rate-limiting steps of the enzyme-controlled reaction whereby a slower enzyme-catalyzed substrate conversion step (k 2) relative to the enzyme-substrate binding step (k-1) was suggested to occur. No significant differences in carbon and hydrogen isotopic fractionation were observed between a methanogenic enrichment culture and cell free extract experiments during toluene degradation. These results indicated that substrate transport across the cell membrane of the microorganisms involved in biodegradation did not influence isotopic fractionation in this culture.Overall, the results of this thesis demonstrated that resolvable differences in carbon and hydrogen isotopic fractionation were not random but occurred for different microbial communities, biodegradation pathways and growth conditions. Significant 13C and 2H enrichment occurred in all experiments carried out in this thesis, indicating that carbon and hydrogen CSIA has the potential to identify in situ biodegradation of benzene and toluene. In addition, the variability in carbon and hydrogen enrichment factors did not significantly impact the ability to use stable isotope analysis to quantify in situ biodegradation. The measurement of both carbon and hydrogen isotope analysis in laboratory experiments and a field study demonstrated that a two-element isotopic approach is the best approach to differentiate between in situ biodegradation and sources of groundwater contamination, as well as potentially delineate between biodegradation pathways.
Download or read book Use of compound specific stable isotopes of carbon and chlorine for source tracking and assessments of biodegradation potential in a chlorinated solvent plume in Fort Worth Texas written by Christopher Lee Braun and published by . This book was released on 2005 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Stable Isotopic and Molecular Biological Tools to Validate Biodegradation of 1 4 dioxane written by Peerapong Pornwongthong and published by . This book was released on 2014 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt: 1,4-Dioxane, a probable human carcinogen, is a heterocyclic ether increasingly found as a contaminant in water supplies. Recent studies have reported that 1,4-dioxane can be biodegraded by a variety of microorganisms, and bioremediation may be an effective strategy for 1,4-dioxane contaminated sites. However, reliable monitoring tools to validate biodegradation of 1,4-dioxane are still lacking. Molecular biological tools and stable isotope-based tools have been previously applied as diagnostic tools for monitored natural attenuation and engineered bioremediation of various organic and inorganic compounds. In this study, molecular biological tools were used for determining bacterial populations, and for associating 1,4-dioxane biodegradation with relative copy numbers of phylogenetic and functional genes. These biomarkers were amplified using primers designed from the genome sequence data of 1,4-dioxane-degrading bacterium Pseudonocardia dioxanivorans CB1190, and were correlated with measured biodegradation rates. The results revealed that abundance of DXMO and 16S rRNA were in agreement with 1,4-dioxane biodegradation rates, and could be used to illustrate the inhibitory effect of co-contaminant transition metals Cu(II), Cd(II), Ni(II), and organic ligands such as tannic acid and L-cysteine. It should be recognized that biomarkers provide an indirect association between genes and enzyme activity. Factors regulating protein synthesis and catalytic activities of enzymes are not captured by nucleic acid-based biomarkers. This complicates the interpretation of biomarkers for predicting biodegradation rates. Compound specific isotope analysis (CSIA) could be used as another diagnostic tool to assess 1,4-dioxane biodegradation. In this study, hydrogen and carbon isotope analyses of 1,4-dioxane were successfully developed to determine isotope signatures of commercial 1,4-dioxane, and applied to determine kinetic isotope fractionation associated with biodegradation in both pure and mixed cultures, as well as abiotic degradation of 1,4-dioxane. During biodegradation, both 2H and 13C were enriched, while abiotic processes could enrich only 2H in residual 1,4-dioxane. This indicated that combined carbon and hydrogen isotope analyses of 1,4-dioxane allow differentiation of biological processes from abiotic mechanisms. Availability of stable isotopic and molecular biological tools will allow environmental engineering professionals to include bioremediation as an effective strategy in the cleanup of specific environmental contaminants.
Download or read book Investigations of Biodegradability and Toxicity of Organic Compounds written by Jan Dojlido and published by . This book was released on 1979 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monitored Natural Attenuation of Inorganic Contaminants in Ground Water written by and published by . This book was released on 2007 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: V.3 ... consists of individual chapters that describe 1) the conceptual background for radionuclides, including tritium, radon, strontium, technetium, uranium, iodine, radium, thorium, cesium, plutonium-americium and 2) data requirements to be met during site characterization.
Download or read book Biodegradation and Bioremediation written by Blaise Lindsey and published by Scientific e-Resources. This book was released on 2018-10-11 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biodegradation is the break down of organic matter by microbes. Bioremediation is an engineered technique applied by people to clean up organic matter by helping microbes with the biodegradation process. One way of doing that is to introduce oxygen into the subsurface to help more aerobic microbes grow in order to clean up oil in the soil.The potential toxicity (harmful action) inherent in a substance is manifest only when that substance comes in contact with that susceptible living biological system. A chemical normally thought of as "e;harmless"e; will evoke a toxic response if added to a biological system in sufficient amount. The toxic potency of a chemicals is defined by the relationship between dose (the amount) of the chemical and the response that is produced in a biological system. The toxicity of industrial wastes is not often managed and it has caused serious damage to earth and water. The most important aspect of environmental biotechnology is the effective management of hazardous and toxic pollutants (xenobiotics) by bioremediation. The environmental clean-up process through bioremediation can be achieved in two ways-in situ and ex situ bioremediation. The book aims to provide relevant theoretical and practical frameworks and the latest empirical research findings in this area, along with case studies. It is written for students, academicians and industry professionals who want to improve their understanding of the strategic role of biodegradation and bioremediation at different levels of the biodegradation and bioremediation research and knowledge, that is, heavy metal pollution, toxicity, remediation methods and strategies to manage the waste in industries, which are a global concern.
Download or read book Biodegradation of Chlorinated Solvents written by and published by . This book was released on 2003 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chlorinated solvents are among the most widespread groundwater contaminants in the country, contamination which is also among the most difficult and expensive for remediation. These solvents are biodegradable in the absence of oxygen, but this biodegradation requires both a food source for the organisms (electron donor) and the presence of chlorinated solvent biodegrading organisms. These two requirements are present naturally at some contamination sites, leading to natural attenuation of the solvents. If one or both requirements are absent, then engineered bioremediation either through addition of an external electron donor or through bioaugmentation with appropriate microorganisms, or both, may be used for site remediation. The most difficult case for cleanup is when a large residual of undissolved chlorinated solvents are present, residing as dense -non-aqueous-phase- liquid (DNAPL). A major focus of this study was on the potential for biodegradation of the solvents when pre sent as DNAPL where concentrations are very high and potential for toxicity to microorganisms exist. Another focus was on a better understanding of the biological mechanisms involved in chlorinated solvent biodegradation . These studies were directed towards the chlorinated solvents, trichloroethene (TCE), tetrachloroethene or perchloroethene (PCE), and carbon tetrachloride (CT). The potential for biodegradation of TCE and PCE DNAPL was clearly demonstrated in this research. From column soil studies and batch studies we found there to be a clear advantage in focusing efforts at bioremediation near the DNAPL. Here, chlorinated solvent concentrations are the highest, both because of more favorable reaction kinetics and because such high solvent concentrations are toxic to microorganisms, such as methanogens, which compete with dehalogenators for the electron donor. Additionally, biodegradation near a PCE DNAPL results in an enhanced dissolution rate for the chlorinated solvent, by factors of three to five times, leading to a more rapid clean-up of the DNAPL zone. The most favored electron donor to add is one which partitions well with the chlorinated solvent or can be concentrated near it. Unfortunately, an ideal electron donor, such as vegetable oil, is difficult to introduce and mix with DNAPL in the ground, doing this properly remains an engineering challenge. Numerical model studies have indicated that several factors may significantly influence the rate and extent of enhancement, including the inhibitory effects of PCE and cDCE, the level of ED concentration, DNAPL configuration, and competition for ED. Such factors need to be considered when contemplating engineered DNAPL bioremediation. Pseudomonas stuzeri KC is an organism that transforms CT to carbon dioxide and chloride without the formation of the hazardous intermediate, chloroform. This is accomplished by production and secretion of a molecule called PDTC. This study was direct ed towards determining how PDTC works. Cu (II) at a ratio of 1:1 Cu to PDTC was found to result in the most rapid CT transformation, confirming that the PDTC-Cu complex is both a reactant and a catalyst in CT transformation. CT degradation requires that the PDTC be in a reduced form, which is generated by contact with cell components. Fe(II) inhibits CT transformation by PDTC. Studies indicated that this inhibition is enhanced by some compound or factor in the supernatant with molecular weight greater than 10,000 Da. We have made progress in determining what this factor might be, but have not yet been able to identify it. In related studies, we found that CT transformation by another organism, Shewanella oneidensis MR1, also involves an excreted factor, but this factor is different from PDTC and results in chloroform transformation as an intermediate. Our studies have indicated that this factor is similar to vitamin K2, and we have also confirmed that vitamin K2 does transform C T into chloroform.
Download or read book Biodegradation of Hazardous and Special Products written by Rolando Chamy and published by BoD – Books on Demand. This book was released on 2013-06-14 with total page 189 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains a collection of different research activities that include the biodegradation compounds with contaminant characteristics and special products of different interests as an added value product or that allows following up various biological processes. The chapters consider the degradation of contaminant compounds generated by industrial activities, i.e., oil industry by-product compounds and halogen compounds or compound generated by natural phenomena such as tsunamis, which require interventions to recover damaged soils. In addition, the book contains chapters that involve special product degradation processes such as chlorophyll, which corresponds to a biological process indicator as photosynthesis.
Download or read book Alternatives for Managing the Nation s Complex Contaminated Groundwater Sites written by National Research Council and published by National Academies Press. This book was released on 2013-02-27 with total page 423 pages. Available in PDF, EPUB and Kindle. Book excerpt: Across the United States, thousands of hazardous waste sites are contaminated with chemicals that prevent the underlying groundwater from meeting drinking water standards. These include Superfund sites and other facilities that handle and dispose of hazardous waste, active and inactive dry cleaners, and leaking underground storage tanks; many are at federal facilities such as military installations. While many sites have been closed over the past 30 years through cleanup programs run by the U.S. Department of Defense, the U.S. EPA, and other state and federal agencies, the remaining caseload is much more difficult to address because the nature of the contamination and subsurface conditions make it difficult to achieve drinking water standards in the affected groundwater. Alternatives for Managing the Nation's Complex Contaminated Groundwater Sites estimates that at least 126,000 sites across the U.S. still have contaminated groundwater, and their closure is expected to cost at least $110 billion to $127 billion. About 10 percent of these sites are considered "complex," meaning restoration is unlikely to be achieved in the next 50 to 100 years due to technological limitations. At sites where contaminant concentrations have plateaued at levels above cleanup goals despite active efforts, the report recommends evaluating whether the sites should transition to long-term management, where risks would be monitored and harmful exposures prevented, but at reduced costs.
Download or read book In Situ Bioremediation written by National Research Council and published by National Academies Press. This book was released on 1993-02-01 with total page 225 pages. Available in PDF, EPUB and Kindle. Book excerpt: In situ bioremediationâ€"the use of microorganisms for on-site removal of contaminantsâ€"is potentially cheaper, faster, and safer than conventional cleanup methods. But in situ bioremediation is also clouded in uncertainty, controversy, and mistrust. This volume from the National Research Council provides direction for decisionmakers and offers detailed and readable explanations of: the processes involved in in situ bioremediation, circumstances in which it is best used, and methods of measurement, field testing, and modeling to evaluate the results of bioremediation projects. Bioremediation experts representing academic research, field practice, regulation, and industry provide accessible information and case examples; they explore how in situ bioremediation works, how it has developed since its first commercial use in 1972, and what research and education efforts are recommended for the future. The volume includes a series of perspective papers. The book will be immediately useful to policymakers, regulators, bioremediation practitioners and purchasers, environmental groups, concerned citizens, faculty, and students.
Download or read book Biodegradation of Chlorinated Solvents written by Perry L. McCarty and published by . This book was released on 2003 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The anaerobic biodegradation of chlorinated solvents is of great interest both for natural attenuation and for engineered remediation of these hazardous contaminants in groundwater. Compounds to be studied are carbon tetrachloride (CT) and the chlorinated ethenes, tetrachloroethene (PCE), trichloroethene (TCE) cis-1,2-dichloroethene (cDCE), and vinyl chloride (VC). The chlorinated solvents often are present as dense non-aqueous-phase liquids (DNAPLs), which are difficult to remove. Biodegradation of DNAPLs was previously thought not possible because of toxicity, but recent evidence indicates that under the right conditions, biodegradation is possible. Anaerobic biodegradation of DNAPLs is the major subject of this research. The specific objectives of this multi-investigator effort are: (1) Evaluate the potential for chlorinated solvent biodegradation near DNAPLs, (2) Provide a molecular understanding of the biological mechanisms involved, (3) Determine cellular components involved in carbon tetrachloride transformation by Pseudomonas stutzeri strain KC without chloroform formation.
Download or read book Biodegradation written by Jaime Alvarez and published by . This book was released on 2016 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides an overview of biodegradation. The first chapter provides a detailed description on the ability of Rhodococcus UKMP-5M to act as a biological tool to remediate phenol, chlorinated compounds, nitrile, oil spillage and cyanide which selection was primarily based on their large-scale presence in industrial wastewater. Chapter Two presents advances made in recent decades on the understanding of the metabolic capabilities of sulfate reducing bacteria (SRB) from marine and other types of sediment (i.e., freshwater, estuarine) for the biotransformation of carbon compounds and sulfate that are present as pollutants in several types of waters and soils. Chapter Three concentrates on the different parameters that influence biodegradation speed and energy release potential. Chapter Four reports and discusses several examples on biodegradation with bacteria and fungi of organochlorides, organophosphates, and more recently of pyrethroid pesticides. Chapter Five discusses heavy metals as biodegradation inhibitors of the forest litter in contaminated areas. Chapter Six introduces ecologically feasible ways of treating environments contaminated by BTEX (a mixture of benzene, toluene, ethylbenzene and xylene) based on efficient microbial metabolism.
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 Transverse Dispersion in Liquid Flow Through Porous Media written by Eugene Sidney Simpson and published by . This book was released on 1962 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
