Download or read book Understanding Environmental Reactions of Carbon Tetrachloride Trichloroethylene Perchloroethylene and Arsenic Applying Computational Chemistry Methods written by and published by . This book was released on 2006 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, as the progress of computational abilities has increased, computational chemistry has become an interesting tool for researchers for investigating mechanisms of environmental reactions when results of experimental explorations are not sufficiently clear. In this research, several environmental reactions have been investigated using ab initio and density functional theory (DFT) methods. This research investigated the effect of the reaction energy on the reaction pathway for C-Cl bond cleavage in carbon tetrachloride (CT). Ab initio and density functional theories were used to study adiabatic electron transfer to aqueous phase CT. The potential energies associated with fragmentation of the CT anion radical into a trichloromethyl radical and a chloride ion were explored as a function of the C-Cl bond distance during cleavage. The effect of aqueous solvation was simulated using a continuum conductor-like screening model. Solvation significantly lowered the energies of the reaction products, indicating that the dissociative electron transfer was enhanced by solvation. It was found that reductive dissociation electron transfer of CT undergoes a change from an inner-sphere to an outer-sphere mechanism as the reaction energy is increased. The results showed a liner relationship between the activation energy for the dissociation and the overall energy change, which is in good agreement with the results of the Marcus model. This research also investigated the thermodynamic favorability and resulting structures for chemisorption of trichloroethylene (TCE) and perchloroethylene (PCE) on iron surfaces using periodic DFT with the non-local Perdew-Burke-Enzerhof (PBE) functional. Chemisorption structures were obtained for four physically adsorbed initial configurations. An initial configuration with two carbons (C-bridge) physicallyadsorbed at bridge sites between adjacent iron atoms was shown to be the most stable configuration for TCE, while the mode with two carbons (C-hollow) physically adsorbed at hollow site was verified to be the most stable configuration for PCE. C-Fe bonds were formed via sigma or pi bonds in the complexes formed at C-bridge, top and hollow site. Upon binding with the iron surface, the interaction of the C=C bond still remained as sp2 hybridization. Moreover, the strong chemisorption induced dissociations of C-Cl bonds and formation of Cl-Fe bonds. For both TCE and PCE, modes with two Cl atoms (Cl-bridge) physically adsorbed at bridge sites were found to be the least favorable configuration, in which only two Cl atoms formed bonds with the Fe surface and no C-Fe bonds were formed. Negative net Mulliken charges on TCE and PCE indicated they are reduced upon adsorption to the iron surface. Finally, in this research, we evaluated the accuracies and costs of several DFT methods including Harris, PWC LDA, and BLYP GGA functionals for interaction of arsenite with ferric hydroxides by comparison to calculated and experimental properties of surface complexes. It was found that the approach of using low-level structures coupled with high level single-point energies was much less expensive than the approach of using high level functionals for both structures and energies and could obtain similar computed binding energies. Further work has been done to investigate the appropriate models for interaction of arsenite with ferric hydroxide between pH values of -4 through +4. The effect of solvation on single point energy was calculated using COSMO models. The bidentate corner-sharing complexes were more energetically favorable than monodentate corner-sharing complexes for the entire pH range. Lower binding energies at some pH values indicated monodentate binding may contribute to adsorption at low pH values and at high pH values. Adsorbed arsenite species were found to be fully protonated at low pH values and partly protonated at high pH values for the most favorable complex. Models for the interaction of arsenite with ferric hydroxide provided a relationship of adsorption and pH values that the adsorption of arsenite increased as pH value increased and there was a maximum point around pH 8.5-9.

Download or read book Dissertation Abstracts International written by and published by . This book was released on 2006 with total page 886 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Applications of Environmental Aquatic Chemistry written by Eugene R. Weiner and published by CRC Press. This book was released on 2012-12-07 with total page 625 pages. Available in PDF, EPUB and Kindle. Book excerpt: Professionals and students who come from disciplines other than chemistry need a concise yet reliable guide that explains key concepts in environmental chemistry, from the fundamental science to the necessary calculations for applying them. Updated and reorganized, Applications of Environmental Aquatic Chemistry: A Practical Guide, Third Edition provides the essential background for understanding and solving the most frequent environmental chemistry problems. Diverse and self-contained chapters offer a centralized and easily navigable framework for finding useful data tables that are ordinarily scattered throughout the literature. Worked examples provide step-by-step details for frequently used calculations, drawing on case histories from real-world environmental applications. Chapters also offer tools for calculating quick estimates of important quantities and practice problems that apply the principles to different conditions. This practical guide provides an ideal basis for self-study, as well as short courses involving the movement and fate of contaminants in the environment. In addition to extensive reorganization and updating, the Third Edition includes a new chapter, Nutrients and Odors: Nitrogen, Phosphorus, and Sulfur, two new appendices, Solubility of Slightly Soluble Metal Salts and Glossary of Acronyms and Abbreviations Used in this Book, and new material and case studies on remediation, stormwater management, algae growth and treatment, odor control, and radioisotopes.

Download or read book Reducing Environmental Cancer Risk written by Suzanne H. Reuben and published by DIANE Publishing. This book was released on 2010-10 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Though overall cancer incidence and mortality have continued to decline in recent years, cancer continues to devastate the lives of far too many Americans. In 2009 alone, 1.5 million American men, women, and children were diagnosed with cancer, and 562,000 died from the disease. There is a growing body of evidence linking environmental exposures to cancer. The Pres. Cancer Panel dedicated its 2008¿2009 activities to examining the impact of environmental factors on cancer risk. The Panel considered industrial, occupational, and agricultural exposures as well as exposures related to medical practice, military activities, modern lifestyles, and natural sources. This report presents the Panel¿s recommend. to mitigate or eliminate these barriers. Illus.

Download or read book Hazardous Chemicals Handbook written by P A CARSON and published by Elsevier. This book was released on 2013-10-22 with total page 389 pages. Available in PDF, EPUB and Kindle. Book excerpt: Summarizes core information for quick reference in the workplace, using tables and checklists wherever possible. Essential reading for safety officers, company managers, engineers, transport personnel, waste disposal personnel, environmental health officers, trainees on industrial training courses and engineering students. This book provides concise and clear explanation and look-up data on properties, exposure limits, flashpoints, monitoring techniques, personal protection and a host of other parameters and requirements relating to compliance with designated safe practice, control of hazards to people's health and limitation of impact on the environment. The book caters for the multitude of companies, officials and public and private employees who must comply with the regulations governing the use, storage, handling, transport and disposal of hazardous substances. Reference is made throughout to source documents and standards, and a Bibliography provides guidance to sources of wider ranging and more specialized information. Dr Phillip Carson is Safety Liaison and QA Manager at the Unilever Research Laboratory at Port Sunlight. He is a member of the Institution of Occupational Safety and Health, of the Institution of Chemical Engineers' Loss Prevention Panel and of the Chemical Industries Association's `Exposure Limits Task Force' and `Health Advisory Group'. Dr Clive Mumford is a Senior Lecturer in Chemical Engineering at the University of Aston and a consultant. He lectures on several courses of the Certificate and Diploma of the National Examining Board in Occupational Safety and Health. [Given 5 star rating] - Occupational Safety & Health, July 1994 - Loss Prevention Bulletin, April 1994 - Journal of Hazardous Materials, November 1994 - Process Safety & Environmental Prot., November 1994

Download or read book Mineral water Interfacial Reactions written by Donald L. Sparks and published by . This book was released on 1998 with total page 460 pages. Available in PDF, EPUB and Kindle. Book excerpt: Clearly explains how to more effectively decipher and predict contaminant fate in the environment by combining kinetic methods and molecular-scale spectroscopic and microscopic techniques to analyze mineral/water interfacial reactions in situ. The book begins with a broad overview, then continues with three sections written by internationally known expert. The first deals specifically with spectroscopic/microscopic techniques that can be used in combination with macroscopic approaches to glean mechanistic information on mineral/water reactions and processes. The second section emphasizes computer models that are used to elucidate surface mediated reaction mechanisms. The remainder of the volume is organized around reaction type, including sorption/desorption of inorganic species, sorption/desorption of organic species, precipitation/dissolution processes, heterogeneous electron transfer reactions, photochemically driven reactions, and microbially mediated reactions. Mineral-Water Interfacial Reactions will be a valuable resource for environmental scientists, geochemists, soil chemists, microbiologists, and marine engineers who need to be familiar with the most current and effective methods for testing and controlling the mobility, speciation, and bioavailability of contaminants in the environment.

Download or read book Advanced Oxidation Processes for Water and Wastewater Treatment written by Simon Parsons and published by IWA Publishing. This book was released on 2004-03-01 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: The suitability of Advanced Oxidation Processes (AOPs) for pollutant degradation was recognised in the early 1970s and much research and development work has been undertaken to commercialise some of these processes. AOPs have shown great potential in treating pollutants at both low and high concentrations and have found applications as diverse as ground water treatment, municipal wastewater sludge destruction and VOCs control. Advanced Oxidation Processes for Water and Wastewater Treatment is an overview of the advanced oxidation processes currently used or proposed for the remediation of water, wastewater, odours and sludge. The book contains two opening chapters which present introductions to advanced oxidation processes and a background to UV photolysis, seven chapters focusing on individual advanced oxidation processes and, finally, three chapters concentrating on selected applications of advanced oxidation processes. Advanced Oxidation Processes for Water and Wastewater Treatment will be invaluable to readers interested in water and wastewater treatment processes, including professionals and suppliers, as well as students and academics studying in this area. Dr Simon Parsons is a Senior Lecturer in Water Sciences at Cranfield University with ten years' experience of industrial and academic research and development.

Download or read book Chemical Oxidation Applications for Industrial Wastewaters written by Olcay Tunay and published by IWA Publishing. This book was released on 2010-10-12 with total page 361 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the most recent scientific and technological developments (state-of-the-art) in the field of chemical oxidation processes applicable for the efficient treatment of biologically-difficult-to-degrade, toxic and/or recalcitrant effluents originating from different manufacturing processes. It is a comprehensive review of process and pollution profiles as well as conventional, advanced and emerging treatment processes & technologies developed for the most relevant and pollution (wet processing)-intensive industrial sectors. It addresses chemical/photochemical oxidative treatment processes, case-specific treatability problems of major industrial sectors, emerging (novel) as well as pilot/full-scale applications, process integration, treatment system design & sizing criteria (figure-of-merits), cost evaluation and success stories in the application of chemical oxidative treatment processes. Chemical Oxidation Applications for Industrial Wastewaters is an essential reference for lecturers, researchers, industrial and environmental engineers and practitioners working in the field of environmental science and engineering. Visit the IWA WaterWiki to read and share material related to this title: http://www.iwawaterwiki.org/xwiki/bin/view/Articles/CHEMICALOXIDATIONAPPLICATIONSFORINDUSTRIALWASTEWATERS Authors: Professor Olcay Tünay, Professor Isik Kabdasli, Associate Professor Idil Arslan-Alaton and Assistant Professor Tugba Ölmez-Hanci, Environmental Engineering Department, Istanbul Technical University, Turkey.

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 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 Physical and Chemical Processes in the Aquatic Environment written by Erik R. Christensen and published by John Wiley & Sons. This book was released on 2014-09-15 with total page 447 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is need in environmental research for a book on fresh waters including rivers and lakes. Compared with other books on the topic, this book has a unique outline in that it follows pollution from sources to impact. Included in the text is the treatment of various tracers, ranging from pathogens to stable isotopes of elements and providing a comprehensive discussion which is lacking in many other books on pollution control of natural waters. Geophysical processes are discussed emphasizing mixing of water, interaction between water and the atmosphere, and sedimentation processes. Important geochemistry processes occurring in natural waters are described as are the processes specific to nutrients, organic pollutants, metals, and pathogens in subsequent chapters. Each of these chapters includes an introduction on the selected groups, followed by the physicochemical properties which are the most relevant to their behavior in natural waters, and the theories and models to describe their speciation, transport and transformation. The book also includes the most up to date information including a discussion on emerging pollutants such as brominated and phosphate flame retardants, perflurochemicals, and pharmaceutical and personal care products. Due to its importance an ecotoxicology chapter has been included featuring molecular biological methods, nanoparticles, and comparison of the basis of biotic ligand model with the Weibull dose-response model. Finally, the last chapter briefly summarizes the regulations on ambient water quality.

Download or read book Permeable Barriers for Groundwater Remediation written by Arun R. Gavaskar and published by . This book was released on 1998 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: Because of the limitations of conventional pump-and-treat systems in treating groundwater contaminants, permeable barriers are potentially more cost-effective than pump-and-treat systems for treating dissolved chlorinated solvent plumes, which may persist in the saturated zone for several decades. Other contaminants, such as chromium or other soluble heavy metals, can also be treated with this technology. Permeable Barriers for Groundwater Remediation discusses the types of permeable barriers, their design and construction, and how they can be monitored to evaluate compliance. It provides practical guidance on reactive media selection, treatability testing, hydrogeologic and geochemical modeling, and innovative installation techniques for the evaluation and application of this promising new technology. The types of permeable barriers discussed include: trench-type and caisson-based reactive cells; innovative emplacements, such as horizontal trenching and jetting; and continuous reactive barriers versus funnel-and-gate systems.

Download or read book Environmental Mineralogy written by J. D. Cotter-Howells and published by . This book was released on 2000 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Green Solvents for Chemistry written by William M. Nelson and published by Oxford University Press. This book was released on 2003-03-27 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this book is to introduce the use of green solvents throughout chemistry and to provide a comprehensive reference for solvents currently applicable in green chemistry. The first section covers solvents in chemical perspective, and the second section is a guide to green solvents. Overall, this volume defines characteristics of green solvents and their current usage, and explores their importance ecologically and economically. It includes a full range of commercial, industrial, and academic green solvents, and discusses solvents in specific commercial and non-commercial practices. Green Solvents for Chemistry differs from other works on solvents in that only solvents for green chemistry are included along with their chemical properties and toxicological issues.

Download or read book Advances in Environmental Pollution Management Wastewater Impacts and Treatment Technologies written by Vinod Kumar and published by Agro Environ Media, Publication Cell of AESA, Agriculture and Environmental Science Academy,. This book was released on 2020-12-05 with total page 229 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Environmental Pollution Management: Wastewater Impacts and Treatment Technologies has been designed to bind novel knowledge of wastewater pollution-induced impacts on various aspects of our environment. The book also contains novel methods and tools for the monitoring and treatment of produced wastewater.

Download or read book EPA Publications Bibliography written by United States. Environmental Protection Agency and published by . This book was released on 1985 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Solar Detoxification written by Julián Blanco Gálvez and published by UNESCO. This book was released on 2003 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: Solar detoxification, an innovative process of water treatment using solar technology, is ready for practical application after a decade of research and development. This is of great significance as 70 per cent of the world's population currently lives within the 'sun belt', where sustainable solar technologies are feasible--a proportion due to increase in the future. Divided into two parts, the first part addresses the theory and fundamentals of water decontamination using solar energy. This prepares .the reader for the second part of the book, which addresses practical applications and engineering processes. Although the book targets university students and post graduates it can also be read by any professional or technician as all subjects are treated in depth, with scientific rigor, but are also attractively presented with a profusion of pictures and graphics. No specific previous knowledge is necessary.