Download or read book DNAPL Source Control by Reductive Dechlorination with Iron based Degradative Solidification stabilization written by Si Hyun Do and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Iron-based degradative solidification/stabilization (Fe(II)-DS/S) is a treatment method that could be economically applied to smaller DNAPL-contaminated sites and to those sites with impermeable soils. Reductive dechlorination is achieved by compounds that are formed by reaction of ferrous iron with components of Portland cement or with defined chemicals (FeCl3 + Ca(OH)2). These dechlorinating agents can effectively degrade chlorinated hydrocarbons (PCE, TCE, and 1,1,1-TCA) that are dissolved in aqueous solution. This research investigated the application of Fe(II)-DS/S to remove chlorinated hydrocarbons that are present as DNAPLs in source zones and to compared the reactivity of ferrous iron in different mixtures, including the conventional mixture with cement (Fe(II)+C) and an iron-solid mixture (ISM) that was synthesized without the addition of cement. The modified first-order model, which the rate was proportional to the concentration of target in the aqueous phase and it was also nearly constant when DNAPL was present, was developed to describe dechlorination kinetics. The modified second-order model assumed that the rate was proportional to the product of the concentration of target in the aqueous phase and the concentration of reductive capacity of the solid reductant. The modified first-order model was used to describe degradation of target compounds with ISM, and the modified second-order model was used to describe removals for TCE and 1,1,1-TCA with Fe(II)+C. Results of experiments on PCE dechlorination with ISM indicated that the increase of Fe(II) in ISM increased rate constants and decreased the solubility of targets. The half-life was increased with increasing total PCE concentration. The product analysis implied that degradation of PCE with ISM was via a combination of the hydrogenolysis and [beta]-elimination pathways. A comparison of the types of targets and reductants indicated that Fe(II)+C had better reactivity for chlorinated ethenes (PCE and TCE) than ISM. However, ISM could dechlorinate a chlorinated ethane (1,1,1-TCA) as rapidly as Fe(II)+10%C. The ratio of [RC]°/[Fe(II)]° implied that Fe(II) in Fe(II)+C was more involved in reducing chlorinated ethenes than was Fe(II) in ISM. Dechlorination of a DNAPL mixture followed the same order of reactivity as with individual DNAPLs with both reductants.
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 Reductive Dechlorination of Chlorinated Aliphatic Hydrocarbons by Fe II in Degradative Solidification stabilization written by Bahng Mi Jung and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation examines the applicability of the iron-based degradative solidification/stabilization (DS/S-Fe(II)) to various chlorinated aliphatic hydrocarbons (CAHs) that are common chemicals of concern at contaminated sites. The research focuses on the transformation of 1,1,1-trichloroethane (1,1,1-TCA), 1,1,2,2-tetrachloro-ethane (1,1,2,2-TetCA) and 1,2-dichloroehtane (1,2-DCA) by Fe(II) in cement slurries. It also investigates the degradation of 1,1,1-TCA by a mixture of Fe(II), cement and three iron-bearing phyllosilicates. Transformation of 1,1,1-TCA and 1,1,2,2-TetCA by Fe(II) in 10% cement slurries was characterized using batch reactors. Dechlorination kinetics of 1,1,1-TCA and TCE* (TCE that was produced by transformation of 1,1,2,2-TetCA) was strongly dependent on Fe(II) dose, pH and initial target organic concentration. Degradation of target organics in DS/S-Fe(II) process was generally described by a pseudo-first-order rate law. However, saturation relationships between the rate constants and Fe(II) dose or between the initial degradation rates and target organic concentration were observed. These behaviors were properly described by a modified Langmuir-Hinshelwood kinetic model. This supports the working hypothesis of this research that reductive dechlorination of chlorinated ethanes occurs on the surface of active solids formed in mixtures of Fe(II) and cement. Transformation products for 1,1,1-TCA and 1,1,2,2-TetCA in mixtures of Fe(II) and cement were identified. The major product of the degradation of 1,1,1-TCA was 1,1-DCA, which indicates that the reaction followed a hydrogenolysis pathway. However, a small amount of ethane was also observed. TCE* was rapidly produced by degradation of 1,1,2,2-TetCA and is expected to undergo [beta]-elimination to produce acetylene. Dechlorination of 1,1,1-TCA in suspension of Fe(II), cement and three soil minerals (biotite, vermiculite, montmorillonite) was characterized using batch reactors. A first-order rate model was generally used to describe the dechlorination kinetics of 1,1,1-TCA in this heterogeneous system. The rate constants for 1,1,1-TCA in mixtures of Fe(II), cement and soil minerals were influenced by soil mineral types, Fe(II) dose and the mass ratio of cement to soil mineral. It was demonstrated that structural Fe(II) and surface-bound Fe(II) in the soil minerals affect dechlorination kinetics and the effects vary with mineral types. Furthermore, it suggests that the reductant formed from Fe(II) and cement hydration components is also effective in systems that include soil minerals.
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 Dechlorination of Chlorinated Hydrocarbons Using Fe II and Modified Green Rusts in Degradative Solidification stabilization written by Sukil Son and published by . This book was released on 2002 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Contaminants in the Subsurface written by National Research Council and published by National Academies Press. This book was released on 2005-04-23 with total page 371 pages. Available in PDF, EPUB and Kindle. Book excerpt: At hundreds of thousands of commercial, industrial, and military sites across the country, subsurface materials including groundwater are contaminated with chemical waste. The last decade has seen growing interest in using aggressive source remediation technologies to remove contaminants from the subsurface, but there is limited understanding of (1) the effectiveness of these technologies and (2) the overall effect of mass removal on groundwater quality. This report reviews the suite of technologies available for source remediation and their ability to reach a variety of cleanup goals, from meeting regulatory standards for groundwater to reducing costs. The report proposes elements of a protocol for accomplishing source remediation that should enable project managers to decide whether and how to pursue source remediation at their sites.
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 Soil Pollution written by Ibrahim Mirsal and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: This graduate-level text and reference work is unique among the soil literature. It deals with the interdisciplinary fields of soil pollution and remediation. It starts off with a thorough and comprehensible introduction to the relevant fundamentals of mineralogy, chemistry, and soil properties. Readers are thus well prepared to understand the biochemical aspects of soil remediation then presented. The book’s holistic approach and narrative style are complemented by numerous and detailed illustrations. Soil pollution is an asset not only to graduate students and instructors, but also to professionals from the environmental and agricultural sciences, as it provides an integrated overview of previously separately treated material.
Download or read book Groundwater Remediation and Treatment Technologies written by Nicholas P. Cheremisinoff and published by Elsevier. This book was released on 1998-12-31 with total page 409 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume has been organized for practicing engineers who deal with the problems of groundwater and leachate remediation. It is intended to provide a practical overview of both techniques for evaluating groundwater quality and in selecting remediation technologies that are cost effective. Emphasis is given to advanced remediation methods.
Download or read book Alternatives for Ground Water Cleanup written by National Research Council and published by National Academies Press. This book was released on 1994-02-01 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt: There may be nearly 300,000 waste sites in the United States where ground water and soil are contaminated. Yet recent studies question whether existing technologies can restore contaminated ground water to drinking water standards, which is the goal for most sites and the result expected by the public. How can the nation balance public health, technological realities, and cost when addressing ground water cleanup? This new volume offers specific conclusions, outlines research needs, and recommends policies that are technologically sound while still protecting health and the environment. Authored by the top experts from industry and academia, this volume: Examines how the physical, chemical, and biological characteristics of the subsurface environment, as well as the properties of contaminants, complicate the cleanup task. Reviews the limitations of widely used conventional pump-and-treat cleanup systems, including detailed case studies. Evaluates a range of innovative cleanup technologies and the barriers to their full implementation. Presents specific recommendations for policies and practices in evaluating contamination sites, in choosing remediation technologies, and in setting appropriate cleanup goals.
Download or read book Environmental and Pollution Science written by Mark L. Brusseau and published by Academic Press. This book was released on 2019-02-22 with total page 662 pages. Available in PDF, EPUB and Kindle. Book excerpt: Environmental and Pollution Science, Third Edition, continues its tradition on providing readers with the scientific basis to understand, manage, mitigate, and prevent pollution across the environment, be it air, land, or water. Pollution originates from a wide variety of sources, both natural and man-made, and occurs in a wide variety of forms including, biological, chemical, particulate or even energy, making a multivariate approach to assessment and mitigation essential for success. This third edition has been updated and revised to include topics that are critical to addressing pollution issues, from human-health impacts to environmental justice to developing sustainable solutions. Environmental and Pollution Science, Third Edition is designed to give readers the tools to be able to understand and implement multi-disciplinary approaches to help solve current and future environmental pollution problems. Emphasizes conceptual understanding of environmental systems and can be used by students and professionals from a diversity of backgrounds focusing on the environment Covers many aspects critical to assessing and managing environmental pollution including characterization, risk assessment, regulation, transport and fate, and remediation or restoration New topics to this edition include Ecosystems and Ecosystem Services, Pollution in the Global System, Human Health Impacts, the interrelation between Soil and Human Health, Environmental Justice and Community Engagement, and Sustainability and Sustainable Solutions Includes color photos and diagrams, chapter questions and problems, and highlighted key words
Download or read book Groundwater Engineering written by Rajandrea Sethi and published by Springer. This book was released on 2019-07-03 with total page 439 pages. Available in PDF, EPUB and Kindle. Book excerpt: This textbook employs a technical and quantitative approach to explain subsurface hydrology and hydrogeology, and to offer a comprehensive overview of groundwater-related topics such as flow in porous media, aquifer characterization, contaminant description and transport, risk assessment, and groundwater remediation. It describes the characterization of subsurface flow of pristine and polluted water and provides readers with easily applicable tools for the design of water supply systems, drinking-water source protection, and remediation interventions. Specific applications range from groundwater exploitation as a drinking water supply to the remediation of contaminated aquifers, from the definition and safeguarding of drinking-water sources to the assessment of human health risks in connection with groundwater contamination events. The book represents an ideal learning resource for upper-undergraduate and graduate students of civil engineering, environmental engineering, and geology, as well as practitioners in the fields of water resource management and environmental protection who are interested in groundwater engineering and technical hydrogeology.
Download or read book Geoenvironmental Engineering written by Lakshmi Reddi and published by CRC Press. This book was released on 2000-04-18 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt: Applies science and engineering principles to the analysis, design, and implementation of technical schemes to characterize, treat, modify, and reuse/store waste and contaminated media. Includes site remediation.
Download or read book Environmental Engineering Dictionary and Directory written by Thomas M. Pankratz and published by CRC Press. This book was released on 2000-09-22 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: Like most technical disciplines, environmental science and engineering is becoming increasingly specialized. As industry professionals focus on specific environmental subjects they become less familiar with environmental problems and solutions outside their area of expertise. This situation is compounded by the fact that many environmental science
Download or read book Geoenvironmental Engineering written by Raymond N. Yong and published by CRC Press. This book was released on 2000-09-25 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: Why do some contaminants remain in soils indefinitely? How much of a threat do they pose to human health or the environment? The need for effective and economic site decontamination arises daily. Geoenvironmental Engineering: Contaminated Soils, Pollutant Fate, and Mitigation discusses why soils remain contaminated, focusing on the development of the factors, properties, characteristics, and parameters of soils and individual contaminants. Subjects covered include the basic properties of soils affecting accumulation of contaminants, long-term retention of contaminants and their fate, including the development of intermediate products. The author emphasizes the factors, interactions, and mechanisms important in the bonding and partitioning process. He provides the groundwork for determining the fate of pollutants in soils and sediments and their mitigation. Geoenvironmental Engineering: Contaminated Soils, Pollutant Fate, and Mitigation focuses on why soils and sediments remain contaminated, not how they became contaminated in the first place. You will understand why specific contaminants remain in soils and sediments, how much of a threat they pose to human health and the environment, and what steps to take for mitigation. With this information you can determine the extent of the contamination of soils and sediments, how long they will remain a threat, and what methods to use for their remediation.
Download or read book Chemistry of Advanced Environmental Purification Processes of Water written by Erik Sogaard and published by Newnes. This book was released on 2014-04-11 with total page 359 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chemistry of Advanced Environmental Purification Processes of Water covers the fundamentals behind a broad spectrum of advanced purification processes for various types of water, showing numerous applications through worked examples. Purification processes for groundwater, soil water, reusable water, and raw water are examined where they are in use full-scale, as a pilot approach, or in the laboratory. This book also describes the production of ceramic particles (nanochemistry) and materials for the creation of filtration systems and catalysts that are involved. Uses chemistry fundamentals to explain the mechanisms behind the various purification processes Explains in detail process equipment and technical applications Describes the production of ceramic particles and other new materials applicable to filtration systems Includes worked examples
Download or read book Recycling and Reuse of Material Found on Superfund Sites written by Lawrence Smith and published by DIANE Publishing. This book was released on 1995-02 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides assistance in identifying recycling technologies for a wide variety of contaminants and matrices, including: energy recovery; decanting; thermal desorption; solvent extraction; pumping and recovery; freeze-crystallization; thermolysis; ion exchange; reverse osmosis; diffusion dialysis; evaporation; amalgamation; cementation; electrowinning; vitrification; physical separation; mercury distillation, etc. Contents: description of recycling technologies; product quality specifications; 8 case studies. Extensive references. 50 charts and tables.
