Download or read book Degradation of Chlorinated Aromatic Compounds Using Zero valent Metals written by Punam Patel and published by . This book was released on 2006 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Reductive Dechlorination of Chlorinated Aliphatic and Aromatic Compounds Using Zero Valent Metals written by Young-Hun Kim and published by . This book was released on 1999 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Chemical Degradation Methods for Wastes and Pollutants written by Matthew A. Tarr and published by CRC Press. This book was released on 2003-08-08 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chemical Degradation Methods for Wastes and Pollutants focuses on established and emerging chemical procedures for the management of pollutants in industrial wastewater and the environment. This reference offers an in-depth explanation of the degradation process, mechanisms, and control factors affecting each method, as well as issues crucial to the application of these approaches in real-world treatment sites. It examines ten of the most common and useful chemical technologies for environmental remediation and sanitation of industrial waste streams and offers implementation guidelines and examples of remediation strategies that are crucial to effective wastewater cleansing.

Download or read book The Destructive Removal of Chlorinated Organic Compounds from Water Using Zero valent Metals Or Hydrogen and Supported Palladium written by Cindy Gail Schreier and published by . This book was released on 1995 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Abiotic Degradation of Chlorinated Hydrocarbons CHCs with Zero valent Magnesium ZVM and Zero valent Palladium Bimetallic Pd Mg reductant written by Fang Yu and published by . This book was released on 2013 with total page 71 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chlorinated hydrocarbons (CHCs) in groundwater can be treated by monometallic and bimetallic metal reductants through abiotic degradation. The breakdown of CHC is achieved by gaining electrons from those reductants and removing chlorines from CHC molecules to transform the CHCs into less chlorinated compounds. As a proven technology in groundwater treatment, permeable reactive barriers (PRBs) have been used to passively treat contaminated groundwater, in which granular metals can be used as reactive materials. This study explored the abiotic degradation of CHCs by zero-valent magnesium (ZVM) and bimetallic palladium/magnesium (Pd/Mg) reductants. Different CHCs (carbon tetrachloride, chloroform, dichloromethane (DCM), 1,2-dichloroethane (1,2-DCA), 1,1,2-trichloroethane (1,1,2-TCA), 1,1,2,2-tetrachloroethane (1,1,2,2-TeCA), 1,2-dichloropropane (1,2-DCP), and 1,2,3-Trichloropropane (1,2,3-TCP) were chosen as target contaminants. Results showed that even with its high reduction potential, ZVM did not treat CHCs effectively due to corrosion of Mg by water, which formed Mg (OH)2(s) precipitate on the metal surface and prevented further reaction. Such inhibition can be reduced by lowering pH conditions. However, in the presence of Pd, CHCs were removed at a much faster rate at neutral pH conditions. Hydrocarbons were produced as sole products, which indicated complete degradation of CHCs by Pd/Mg. Recalcitrant CHCs such as DCM, 1, 1,2-TCA, 1,2-DCP and 1,2,3-TCP were found to be effectively degraded by Pd/Mg. No significant effect of Pd loading on CHC degradation was observed, while the degradation was accelerated by increasing the Mg loading.

Download or read book Investigations of Reductive Dechlorination Reactions of Chlorinated Ethenes and Ethanes on Zero valent Metals Using Compound Specific Isotopic Analysis written by Nancy Anne VanStone and published by . This book was released on 2006 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reductive dechlorination reactions occurring on zero-valent metal surfaces for chlorinated ethenes and chlorinated ethanes are investigated using compound specific isotopic analysis (CSIA) to measure carbon isotopic fractionation and carbon kinetic isotope effects (KIE). Reductive dechlorination of chlorinated contaminants on zero-valent iron (Fe0) is used for remediation purposes at over 100 sites worldwide employing permeable reactive barrier (PRB) technology. Degradation can occur via 3 main pathways: (1) alpha-elimination, (2) beta-elimination and (3) hydrogenolysis. Experiments documenting carbon isotopic fractionation observed during degradation of a suite of chlorinated ethenes are described, and it is demonstrated that reproducible carbon isotopic fractionation occurs for perchloroethene (PCE), trichloroethene (TCE), cis-dichloroethene (cis-DCE) and vinyl chloride (VC). The results for Fe0 from two different sources show distinct differences in both rates of reaction and isotopic fractionation factors (epsilon), particularly for the cis-DCE and VC. Using ground water samples from pre- and post-treatment of a Fe0 PRB at F.E. Warren Air Force Base, it is established that carbon isotopic fractionation of chlorinated ethenes follows the same principles under field conditions, and it is shown that CSIA, in combination with traditional compositional analysis, can help to resolve complex performance-related problems for PRBs. Finally, it is demonstrated that reaction pathways and mechanisms can be investigated using CSIA and ranges of epsilon and KIE are established for the investigated reactions on different zero-valent metals. In batch experiments monitoring dichloroethane (DCA) degradation on Zn0, CSIA was used to determine that a common rate limiting step occurs for hydrogenolysis and alpha-elimination reactions of 1,1-DCA. As well, overall epsilon and KIE are greater for beta-elimination of 1,2-DCA than for hydrogenolysis and alpha-elimination of 1,1-DCA. The degradation of a chlorinated ethene, cis-DCE, was investigated on Fe0. Direct measurements of epsilon and KIE for hydrogenolysis and beta-elimination were measured using CSIA. It is established that these reactions do not share a rate limiting step, and unique and reproducible carbon isotopic fractionation is associated with each reaction pathway. CSIA has been shown to be a versatile tool, aiding research as both a reliable diagnostic (i.e. identification of degradation) and as a valuable analytical instrument for mechanistic studies.

Download or read book Nanotoxicology for Agricultural and Environmental Applications written by Mahendra Rai and published by Elsevier. This book was released on 2024-03-19 with total page 325 pages. Available in PDF, EPUB and Kindle. Book excerpt: Published as part of Elsevier's series, Nanobiotechnology for Plant Protection, Nanotoxicology for Agricultural and Environmental Applications provides an introduction to nanotechnology and its applications in agriculture and the environment.Divided into five parts, this book addresses nanotechnology and regulations, nanotoxicity, nanotoxicity to agriculture and food, nanotoxicity to the environment, and risk management measures to avoid exposure.Students, practitioners, and researchers working in plant science, agricultural science, nanoscience, and environmental chemistry alike will benefit from this necessary reference. - Highlights the factors contributing to toxic effects of nanoparticles, including shape, size, structure, surface charge, and dosage - Explores the mode of action and entry of nanoparticles, methods of toxicity evaluation, and the associated challenges - Describes recent developments in nanotoxicity to soil ecosystems, crop plants, and food systems - Emphasizes the impact of nanoparticles and their detoxification by plants on the nutritional quality of food and plants - Discusses the impact of toxicity of nanoparticles released in air, soil, and water and methods to reduce their effects

Download or read book Nanoparticles as Sustainable Environmental Remediation Agents written by Konstantinos Simeonidis and published by Royal Society of Chemistry. This book was released on 2023-10-18 with total page 317 pages. Available in PDF, EPUB and Kindle. Book excerpt: The expanding use of nanoparticles in a wide range of applications has brought to light the need to adopt an integrated approach regarding their synthesis, use, recovery and handling. This book covers the intense research field of nanoparticle utilization as remediation agents for toxic pollutants, and pays special attention to their post-application recovery, the monitoring of their fate when released, and life cycle analysis. The reader may therefore evaluate the prospects and limitations of these technologies through the prism of sustainability demands. Several chapters summarize successful applications of single or multi-phase nanoparticles for drinking water purification, wastewater and gas-stream treatment and soil consolidation. Importantly, they evaluate the potential scale-up for real-world applications that need to compete with traditional treatment methods. However, the risk of uncontrolled release into the environment can be a significant drawback to the extended use of nanoparticles. For this reason, a detailed analysis is given to aspects of their post-use recycling and regeneration, determination of release pathways, risk assessment methods and life cycle evaluation studies, highlighting the importance of preventing the unintended release of nanoparticles into the environment. This book will be a valuable resource for anyone looking at the development of nanoparticles with a view to environmental remediation strategies.

Download or read book Recent Advances in Microbial Degradation written by . Inamuddin and published by Springer Nature. This book was released on 2021-07-07 with total page 483 pages. Available in PDF, EPUB and Kindle. Book excerpt: Microbes play a major role in the degradation of various pollutants. Therefore, microbes find potential application in the area of energy and environmental technology. The book provides in-depth literature on the topics of environmental and industrial importance. It is compiled to explore the application of microbe used in the degradation of aflatoxin, polymers, biomass into fuel, disinfectants, food products, xenobiotic compounds, lipids, steroids, organic pollutants, proteins, oil waste, and wastewater pollutants. This book will be of interest to teachers, researchers, scientists, and capacity builders. Also, the book serves as additional reading material for undergraduate and graduate students of microbiology and environmental sciences. National and international remediation and restoration scientists, policymakers will also find this to be a useful read.

Download or read book Accelerated Degradation of Chlorinated Solvents by Copper modified Nanoscale Zero Valent Iron Cu nZVI Stabilized with Carboxymethyl Cellulose written by Andrew Franze and published by . This book was released on 2015 with total page 89 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanoscale zero valent iron (nZVI) is a remediation technology that can be used to treat chlorinated hydrocarbons (CHCs) in contaminated aquifers. Nanoparticles remain mobile in water and can be transported with groundwater flow to contaminated zones. However, due to magnetic and van der Waals forces, unstabilized nZVI agglomerates. Carboxymethylcellulose (CMC) was used as a polyelectrolyte stabilizer in this study. nZVI serves as an electron donor and can dechlorinate CHCs. nZVI reactivity with CHCs can be enhanced by addition of a secondary metal catalyst. This study evaluates the potential of copper amended nZVI (Cu-nZVI) to degrade select CHCs. The objective of this study was to characterize degradation of select CHCs in batch reactors with regard to degradation kinetics and degradation byproduct distributions. The following CHCs were studied: CF, 1,1,2,2-TeCA, 1,1,1-TCA, 1,1,2-TCA, PCE, TCE, cis-DCE, trans-DCE, and 1,2,3-TCP. Degradation kinetics were quantified using a pseudo first-order rate constant (kobs). Initial degradation of CHCs was reported separately from later degradation, which occurred after 0.5 hr. The change in reaction kinetics with time could be caused by particle aging. The effect of Cu loading and nZVI concentration was evaluated with CF degradation. Increasing Cu loading or nZVI concentrations yielded faster degradation rates. Increasing Cu loading systematically increased methane byproduct production. The loss of reactivity with CF after 0.5 hr was greater for nZVI when compared to Cu-nZVI. Degradation kinetics were faster and byproduct distribution was more favorable for Cu-nZVI than nZVI for all CHCs studied. Cu-nZVI outperformed most other bimetallic nZVI reductants reported in the literature for CF and chlorinated ethanes treatment. Cu-nZVI invokes a-elimination of CF and 1,l,1-TCA, which produces reactive carbene intermediates capable of degrading into benign products such as methane, ethane, and ethene. Cu-nZVI also showed potential for 1,2,3-TCP remediation. However, Cu-nZVI was particularly ineffective at degrading chlorinated ethenes. Chlorinated ethene degradation pathways and mechanisms induced by Cu-nZVI were not clearly identified. Particle longevity experiments showed that reactivity with 1,1,1-TCA decreases as particles age. Unstable Cu-nZVI particles showed a slow linear decline in reactivity with time, whereas CMC stabilized Cu-nZVI particles showed a rapid power function decline in reactivity with time. The unstable particles were 12-fold faster compared to stablized particles 24 hr after particle synthesis. Even with declines in reactivity, 1,1,1-TCA was rapidly degraded (over a few hours) by both stable and unstable Cu-nZVI seven days after particle synthesis. Cu-nZVI hydrogen production was minor and was limited to occurring immediately after particle synthesis. Cu-nZVI shows great potential for treating certain CHCs.

Download or read book Biodegradation of Nitroaromatic Compounds and Explosives written by Jim C. Spain and published by CRC Press. This book was released on 2000-06-14 with total page 451 pages. Available in PDF, EPUB and Kindle. Book excerpt: Filled with practical applications and research, Biodegradation of Nitroaromatic Compounds and Explosives presents an international perspective on environmental contamination from explosives. It covers biodegradation strategies for DNT and a wide variety of other nitroaromatic compounds of environmental significance and makes the information access

Download or read book Degradation of Chlorinated Hydrocarbon Contaminants by Sulfidated Nanoscale Zerovalent Iron written by Siyuan Mu and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "The application of sulfidated nanoscale zerovalent iron (S-nZVI) for chlorinated solvents dechlorination is a promising treatment approach. The main mechanisms involved in dechlorination are direct electron transfer or indirect electron transfer through reactive atomic hydrogen. The S/Fe molar ratio in S-nZVI has been shown to play a critical role during the reaction as sulfidation to different extent leads to changes in the dechlorination rates, however, past studies have largely focused on one chlorinated solvent compound, trichloroethene (TCE). There is a lack in the understanding of the impact of S/Fe molar ratios on the dechlorination of other environmentally significant chlorinated solvents. In this study, degradation efficiency, associated hydrogen generation, partially dechlorinated products as well as total chloride release were analyzed for 1,1,1-trichloroethane (TCA) and carbon tetrachloride (CT) at 7 different S/Fe molar ratios ranging from 0.01 to 0.4, under stoichiometrically electron excess (Fe0 excess) conditions. TCE was also analyzed as a comparison with previous studies. Optimal S/Fe ratios were determined at S/Fe 0.01 for both 1,1,1-TCA and CT degradation whereas optimal S/Fe ratios for minimum partially dechlorinated product formation were identified at S/Fe 0.4. The optimal S/Fe ratio (0.1) for TCE degradation is different from that of the two other chlorinated solvents and the degradation rate of TCE (0.008 h^-1-0.054 h^-1), 1,1,1-TCA (0.03 h^-1 - 1.13 h^-1) and CT (2 h^-1 - 12.7 h^-1). Degradation of TCE led to complete dechlorination, however measurable amounts of chlorinated organic products (1,1-Dichloromethane and chloroform) were formed during 1,1,1-TCA and CT degradation. These results suggest different degradation mechanisms are likely responsible for the degradation of different chlorinated solvent compounds"--

Download or read book Accelerated Degradation of Chlorinated Solvents by Nanoscale Zero Valent Iron Coated with Iron Monosolfide and Stabilized with Carboxymethyl Cellulose written by Shirin Ghahghaei Nezamabadi and published by . This book was released on 2016 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanoscale zero-valent iron (nZVI) injections have proven to be a promising approach for the remediation of aquifers contaminated by chlorinated organic pollutants. This study compares the efficacy of nZVI in sulfidated and unamended forms in degrading selected chlorinated hyrocarbons (CHCs). Results show that nZVI amended with iron monosulfide (FeS) increases the rate of dechlorination of CT, CF and 1,1,1-TCA compared to that by unamended nZVI. The focus of this research was to characterize degradation kinetics and degradation byproduct distributions of CT, CF and 1,1,1-TCA by nZVI coated by iron monosulfide, which is represented as nZVI/FeS. To prevent nZVI particles from agglomerating, carboxymethylcellulose (CMC) was used as a stabilizer in all experiments. Results indicated that the nZVI/FeS system was faster and produced less toxic byproducts than nZVI for all CHCs studied. a-elimination in nZVI/FeS system was an important degradation pathway for CF and 1,l,1-TCA: it produces reactive carbene intermediates capable of degrading into benign products such as methane, ethane, and ethene. The effect of sulfide loading on degradation was evaluated with all CHCs studied. Regardless of CHC type, the rate constant (kobs) increased with increasing sulfide loading, reaching the highest amount at 1 wt% sulfide, and then decreased with higher sulfide loading. An additional study focused on the effects of varying of the concentration of nZVI and CMC, and particle longevity on the degradation of 1,1,1-TCA in the nZVI/FeS system with 1 wt.% sulfide. Particle longevity experiments showed that reactivity with 1,1,1-TCA decreases as particles age. nZVI/FeS particles showed a rapid power function decline in reactivity with time. Increasing the amount of iron-reducing chemical during nZVI/FeS synthesis improved reactivity by 43%. The addition of a polyelectrolyte stabilizer at an optimized concentration of 4.0 g/L further increased nZVI/FeS reactivity by 350%. nZVI/FeS shows great potential for treating certain CHCs.

Download or read book Advances in Groundwater Pollution Control and Remediation written by Mustafa Aral ARAL and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 602 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the past decades, environmental scientists, economists and physicists have been juggling critical issues within environmental strategies and environmental management styles in order to find a feasible medium between limited resources, long term demands and objectives, and interest groups. In the search for best management alternatives, practice has undergone a pendulum swing between stages that can be characterised as frontier economics, radical environmentalism, resource management/allocation, selective environmentalism and sustainable environmental management. The next stage of management must answer such questions as: `Can there be a global - uniform environmental strategy?', or `Based on their characteristics, can different issues, different regions and different applications have unique environmental strategies?' Based on this premise, the next stage of management may be identified as risk based sustainable environmental management. The goal of this style will be the risk based, long term, harmonious management of economic resources and environmental preservation for health, safety and prosperity of sustainable populations. When evaluation of risk or risk based ranking of management alternatives enter the picture as part of the overall puzzle, then social policy, ethics and health issues assume a very important role in the management strategy. Economic incentives and environmental constraints have to be considered harmoniously, the main emphasis being placed on protection and preservation of human health and the long term sustaining of populations.

Download or read book Nanoscale Zerovalent Iron Particles for Environmental Restoration written by Tanapon Phenrat and published by Springer. This book was released on 2019-01-31 with total page 611 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first complete edited volume devoted to providing comprehensive and state-of-the art descriptions of science principles and pilot- and field-scaled engineering applications of nanoscale zerovalent iron particles (NZVI) for soil and groundwater remediation. Although several books on environmental nanotechnology contain chapters of NZVI for environmental remediation (Wiesner and Bottero (2007); Geiger and Carvalho-Knighton (2009); Diallo et al. (2009); Ram et al. (2011)), none of them include a comprehensive treatment of the fundamental and applied aspects of NZVI applications. Most devote a chapter or two discussing a contemporary aspect of NZVI. In addition, environmental nanotechnology has a broad audience including environmental engineers and scientists, geochemists, material scientists, physicists, chemists, biologists, ecologists and toxicologists. None of the current books contain enough background material for such multidisciplinary readers, making it difficult for a graduate student or even an experienced researcher or environmental remediation practitioner new to nanotechnology to catch up with the massive, undigested literature. This prohibits the reader from gaining a complete understanding of NZVI science and technology. In this volume, the sixteen chapters are based on more than two decades of laboratory research and development and field-scaled demonstrations of NZVI implementation. The authors of each chapter are leading researchers and/or practitioners in NZVI technology. This book aims to be an important resource for all levels of audiences, i.e. graduate students, experienced environmental and nanotechnology researchers, and practitioners evaluating environmental remediation, as it is designed to involve everything from basic to advanced concepts.

Download or read book CRC Concise Encyclopedia of Nanotechnology written by Boris Ildusovich Kharisov and published by CRC Press. This book was released on 2016-01-06 with total page 1203 pages. Available in PDF, EPUB and Kindle. Book excerpt: The CRC Concise Encyclopedia of Nanotechnology sets the standard against which all other references of this nature are measured. As such, it is a major resource for both skilled professionals and novices to nanotechnology.The book examines the design, application, and utilization of devices, techniques, and technologies critical to research at the

Download or read book Emerging Trends to Approaching Zero Waste written by Chaudhery Mustansar Hussain and published by Elsevier. This book was released on 2021-12-04 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt: Emerging Trends to Approaching Zero Waste: Environmental and Social Perspectives thoroughly examines the impact of various technological innovations, current guidelines and social awareness on the reduction of waste, with the ultimate aim of achieving the zero-waste target. Insights in the book will help users adopt the best possible methodologies at grass-root levels and show how modern societal procedures are becoming sustainable, with a goal of zero waste. It comprehensively discusses the scientific contributions of the environmental and social sector, along with the tools and technologies available for achieving the zero-waste targets. This book is the first step toward understanding state-of-the-art practices in making the zero-waste goal a reality. It will be especially beneficial to researchers, academics, upper-level students, waste managers, engineers and managers of industries researching or hoping to implement zero-waste techniques. Uses fundamental, interdisciplinary and state-of-the-art coverage of zero waste research to provide an integrated approach to tools, methodology and indicators for waste minimization Presents a unique look at environmental and social perspectives, challenges and solutions to zero waste Includes up-to-date references and web resources at the end of each chapter, as well as a webpage dedicated to providing supplementary information