Download or read book Arsenate and Arsenite Retention and Release in Oxide and Sulfide Dominated Systems written by Richard H. Loeppert and published by . This book was released on 1997 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Arsenic Contamination of Groundwater written by Satinder Ahuja and published by John Wiley & Sons. This book was released on 2008-10-03 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides a viable reference, describing the state-of-knowledge on sources of arsenic contamination in ground water, which affects about 100 million people worldwide. With contributions from world-renowned experts in the field, this book explores developments in the transport kinetics, detection, measurement, seasonal cycling, accumulation, geochemistry, removal, and toxicology of arsenic. Includes compelling case studies describing how arsenic contamination occurs and the devastating effects on the people and environment affected by it.
Download or read book Microbiology for Minerals Metals Materials and the Environment written by Abhilash and published by CRC Press. This book was released on 2015-02-25 with total page 608 pages. Available in PDF, EPUB and Kindle. Book excerpt: Better Understand the Connection between Microbiology and the Inorganic WorldMicrobiology for Minerals, Metals, Materials and the Environment links chemical, metallurgical, and other metal inherent systems with microbes, and analyzes the interdependence between them. Specifically intended to underscore the importance of microbes in environmental re
Download or read book Advances in Agronomy written by and published by Elsevier. This book was released on 2005-05-11 with total page 431 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Agronomy continues to be recognized as a leading reference and a first-rate source of the latest research in agronomy. Major reviews deal with the current topics of interest to agronomists, as well as crop and soil scientists. As always, the subjects covered are varied and exemplary of the myriad of subject matter dealt with by this long-running serial. Editor Donald Sparks, former president of the Soil Science Society of America and current president of the International Union of Soil Science, is the S. Hallock du Pont Chair of Plant and Soil Sciences at The University of Delaware. Volume 86 contains seven excellent reviews that discuss topics critical to agricultural and environmental sustainability. Topics include: Arsenic Contamination and its Risk Management in Complex Environmental Settings; The Contribution of Breeding to Yield Advances in Maize (Zea mays L.); Metabolic Engineering of Isoflavone Biosynthesis; Biological Control of Weeds With Antagonistic Plant Pathogens; Nutrient Stocks, Nutrient Cycling and Soil Changes in Cocoa Ecosystems – A Review; Rice-Wheat Cropping Systems; Interactions of Nitrogen with Other Nutrients and Water: Effect on Crop Yield and Quality, Nutrient Use Efficiency, Carbon Sequestration and Environmental Pollution. - Maintains the highest impact factor among serial publications in agriculture - Presents timely reviews on important agronomy issues - Enjoys a long-standing reputation for excellence in the field
Download or read book Arsenic in Ground Water written by Alan H. Welch and published by Springer Science & Business Media. This book was released on 2007-05-08 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt: Interest in arsenic in ground water has greatly increased in the past decade because of the increased awareness of human health effects and the costs of avoidance or treatment of ground water supplies used for consumption. The goal of this book is to provide a description of the basic processes that affect arsenic occurrence and transport by providing sufficient background information on arsenic geochemistry and descriptions of hi- arsenic ground water, both affected and unaffected by human activity. An understanding of thermodynamics, adsorption, and the speciation of arsenic in solid phases, which are described in first three chapters, is needed to predict the fate of arsenic in ground water systems. Large-scale and deep movement of ground water can and has redistributed arsenic in the near surface environment, as described in the next two chapters. These large-scale systems can affect large volumes of both ground water and surface water, such as in the Yellowstone system, and can produce mineralised zones that subsequently release arsenic to ground water supplies. Regional identification of high-arsenic ground water and its consumption as described in the next three chapters clearly demonstrates a need for increased wat- quality monitoring, particularly in south and southeast Asia. Chapters 9-11 provide examples of high arsenic ground water associated with sulfide mineral oxidation and alkaline conditions. Finally, smaller scale studies of the effects of human activities that have produced high-arsenic ground water and methods for attenuation of ground water are presented.
Download or read book Arsenic Removal from Water Using Nano scale Metal Oxide Incorporated Highly Ordered Mesoporous Silicate Media written by Min Jang and published by . This book was released on 2003 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Metabolism of Arsenite written by Joanne M. Santini and published by CRC Press. This book was released on 2018-10-03 with total page 203 pages. Available in PDF, EPUB and Kindle. Book excerpt: Up to 200 million people in 70 countries are at risk from drinking water contaminated with arsenic, which is a major cause of chronic debilitating illnesses and fatal cancers. Until recently little was known about the mobility of arsenic, and how redox transformations determined its movement into or out of water supplies. Although human activities contribute to the release of arsenic from minerals, it is now clear that bacteria are responsible for most of the redox transformation of arsenic in the environment. Bacterial oxidation of arsenite (to the less mobile arsenate) has been known since 1918, but it was not until 2000 that a bacterium was shown to gain energy from this process. Since then a wide range of arsenite-oxidizing bacteria have been isolated, including aerobes and anaerobes; heterotrophs and autotrophs; thermophiles, mesophiles and psychrophiles. This book reviews recent advances in the study of such bacteria. After a section on background—geology and health issues—the main body of the book concerns the cellular machinery of arsenite oxidation. It concludes by examining possible applications. Topics treated are: The geology and cycling of arsenic Arsenic and disease Arsenite oxidation: physiology, enzymes, genes, and gene regulation. Community genomics and functioning, and the evolution of arsenite oxidation Microbial arsenite oxidation in bioremediation Biosensors for arsenic in drinking water and industrial effluents
Download or read book Assessment of Arsenic Treatment Residuals written by T. Kramer and published by International Water Assn. This book was released on 2009 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objectives of this research were to (1) conduc
Download or read book Arsenic natural Organic Matter Interactions in Solutions and at Oxide Surfaces written by Vibhash V. Vaidya and published by . This book was released on 2006 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Effective January 2006, the United States Environmental Protection Agency (USEPA) lowered the arsenic Maximum Contaminant Level (MCL) in drinking water from 50 ppb (jig!L) to 10 ppb (jig/L). As a result of this change the USEPA estimates that more than 4000 water systems in the US would be out of compliance, with approximately 97% of the affected users being small water suppliers (output less than 5 million gallons per day) that are often located in rural communities or individual homes. Such small water systems may have little or no existing treatment methods and often do not have the resources to meet the cost associated with the existing proven As-removing technologies. To achieve this end a new media -- Granular Ferric Hydroxide (GFHTM) , developed by Driehaus et al. (1998), could be applied as an effective adsorbent media in the point of use (POU) or point of entry (POE) systems utilized by most small and individual water treatment systems. The presence of natural organic matter (NOM) may affect arsenic adsorption on oxide surfaces resulting in a decrease in arsenic adsorption by either direct competition with arsenic for adsorption sites or formation of non-sorbing arsenic-NOM complexes. Details of these interactions are limited, however, and their importance is currently unknown. This research work is divided into two parts. Part 1 investigated whether As(V)NOM interactions occur in water systems and to characterize such interactions if they occur, while in Part 2 the influence of competing ions (NOM) on arsenic removal using GFH was investigated. The experiments carried out to study As(V)-NOM interactions include potentiometric titrations and dialysis experiments in the presence and absence of divalent calcium cations. The titration experiments were simulated with a model using a discrete ligand approach to capture the chemical behavior of NOM. Results of these simulations suggest there are no direct interactions between arsenic and NOM, indicating more complex mechanisms may be involved. Results from the dialysis experiments suggested calcium assisted in retaining arsenic inside the dialysis bags and thus may act as a "metalbridge" between As(V) and NOM. In Part 2, the adsorption of As(V) and As(III) were examined as a function of equilibration time, pH, GFH size, and presence of NOM. Results from batch equilibrium experiments, conducted for a period of 4 days indicate arsenate adsorption by GFH has a greater dependence on pH than does arsenite. Arsenate adsorption was observed to decrease with increasing pH, consistent with results observed in the literature. Arsenite adsorption in the circumneutral pH range was consistently near 90%; suggesting the oxidation of arsenite to arsenate is not an important pre-requisite for water tratment with GFH as it is for other adsorbents such as activated alumina. Arsenate adsorption was not affected by the presence of NOM below pH 8, whereas for similar NOM and GFH concentrations the presence of arsenate decreased NOM adsorption, suggesting GFH may contain specific As(V)-binding sites or sites inaccessible to the macromolecular NOM. However, these studies employed different GFH size fractions and thus the observations were not directly comparable. Results from batch kinetic studies indicated arsenic adsorption on GFH occurred in two stages - an initial rapid uptake followed by a slower, presumably diffusion-limited process. In the longer-run the diffusion-limited process may be dominated by surface- diffusion within the porous GFH grains as suggested in previous research. The size of GFH particles appeared to affect adsorption kinetics, with the smaller-sized fraction showing a more rapid attainment of equilibrium even though the surface areas of both fractions were similar, suggesting that more surface sites were accessible to arsenate for the smaller-sized GFH fraction than the larger-sized fraction. This might have implications in configuring treatment systems, constrained by operational time periods, with the optimum size of GFH required to obtain the desired effluent arsenic concentration. The results obtained suggest that the nature of the NOM, the redox speciation of arsenic, as well as the surface characteristics of the oxide surface play an important role in affecting the adsorption of arsenic in natural and engineered systems.
Download or read book Environmental Chemistry of Arsenic written by William T. Frankenberger, Jr and published by CRC Press. This book was released on 2001-12-04 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt: With contributions from world-renowned experts in the field, this book explores developments in the transport kinetics, seasonal cycling, accumulation, geochemistry, transformation, and toxicology of arsenic. It details advances in the prevention and control of arsenic and arsenic compounds in the air, soil, and water and offers analytical methods for the detection and study of arsenic in the environment and human body. Providing bioremediation techniques for effective treatment of contaminated water supplies, the book discusses factors that influence the removal of arsenic from water as well as diurnal and seasonal variations in the arsenic concentration of surface water supplies.
Download or read book U S Geological Survey Water supply Paper written by and published by . This book was released on 1982 with total page 472 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 Bioavailability of Contaminants in Soils and Sediments written by National Research Council and published by National Academies Press. This book was released on 2003-05-03 with total page 433 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bioavailability refers to the extent to which humans and ecological receptors are exposed to contaminants in soil or sediment. The concept of bioavailability has recently piqued the interest of the hazardous waste industry as an important consideration in deciding how much waste to clean up. The rationale is that if contaminants in soil and sediment are not bioavailable, then more contaminant mass can be left in place without creating additional risk. A new NRC report notes that the potential for the consideration of bioavailability to influence decision-making is greatest where certain chemical, environmental, and regulatory factors align. The current use of bioavailability in risk assessment and hazardous waste cleanup regulations is demystified, and acceptable tools and models for bioavailability assessment are discussed and ranked according to seven criteria. Finally, the intimate link between bioavailability and bioremediation is explored. The report concludes with suggestions for moving bioavailability forward in the regulatory arena for both soil and sediment cleanup.
Download or read book Geochemical Processes written by Horst D. Schulz and published by Wiley-VCH. This book was released on 2002-12-25 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a result of the Priority Programme 546 run by the Deutsche Forschungsgemeinschaft. It presents the various ideas, concepts and conclusions that resulted from this Programme on the subject of geochemical processes with long-term effects in anthropogenically influenced drainage and ground water.
Download or read book Arsenic in Drinking Water written by National Research Council and published by National Academies Press. This book was released on 2001-12-26 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: Having safe drinking water is important to all Americans. The Environmental Protection Agency's decision in the summer of 2001 to delay implementing a new, more stringent standard for the maximum allowable level for arsenic in drinking water generated a great deal of criticism and controversy. Ultimately at issue were newer data on arsenic beyond those that had been examined in a 1999 National Research Council report. EPA asked the National Research Council for an evaluation of the new data available. The committee's analyses and conclusions are presented in Arsenic in Drinking Water: 2001 Update. New epidemiological studies are critically evaluated, as are new experimental data that provide information on how and at what level arsenic in drinking water can lead to cancer. The report's findings are consistent with those of the 1999 report that found high risks of cancer at the previous federal standard of 50 parts per billion. In fact, the new report concludes that men and women who consume water containing 3 parts per billion of arsenic daily have about a 1 in 1,000 increased risk of developing bladder or lung cancer during their lifetime.
Download or read book Handbook of Arsenic Toxicology written by Swaran Jeet Singh Flora and published by Academic Press. This book was released on 2014-12-26 with total page 752 pages. Available in PDF, EPUB and Kindle. Book excerpt: Throughout history, arsenic has been used as an effective and lethal poison. Today, arsenic continues to present a real threat to human health all over the world, as it contaminates groundwater and food supplies. Handbook of Arsenic Toxicology presents the latest findings on arsenic, its chemistry, its sources and its acute and chronic effects on the environment and human health. The book takes readings systematically through the target organs, before detailing current preventative and counter measures. This reference enables readers to effectively assess the risks related to arsenic, and provide a comprehensive look at arsenic exposure, toxicity and toxicity prevention. - Brings together current findings on the effects of arsenic on the environment and human health - Includes state-of-the-art techniques in arsenic toxicokinetics, speciation and molecular mechanisms - Provides all the information needed for effective risk assessment, prevention and countermeasure
Download or read book Surface Complexation Modeling written by David A. Dzombak and published by John Wiley & Sons. This book was released on 1991-01-16 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides a description of the thermodynamic model, data treatment procedures and the thermodynamic constants for hydrous ferric oxide. Includes detailed coverage of the model and the parameter extraction procedure.
