Download or read book Aquatic Cycling of Selenium written by A. Dennis Lemly and published by . This book was released on 1987 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Selenium Cycling and Impact in Aquatic Ecosystems written by Electric Power Research Institute and published by . This book was released on 2001 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Selenium Assessment in Aquatic Ecosystems written by A. Dennis Lemly and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: Selenium is a naturally occurring trace element that can become concentrated and released by industrial, agricultural, petrochemical and mining activities. At concentrated levels it is toxic and has polluted ecosystems around the world. This book will serve as a comprehensive practical handbook for everyone dealing with selenium in aquatic environments. It offers field-tested approaches and methods for assessment and water quality management. Using his twenty-year experience, the author discusses the effects of selenium on fish and bird populations and presents guidelines for identifying sources of pollution, interpreting selenium concentrations, assessing hazardous conditions, setting water quality criteria and ecosystem loading limits (TMDLs). He also includes a procedure for setting environmentally safe limits that ensure compliance with EPA regulations. Selenium Assessment in Aquatic Ecosystems will interest field scientists, natural resource managers, risk assessors and environmental planners.

Download or read book Ecological Assessment of Selenium in the Aquatic Environment written by Peter M. Chapman and published by CRC Press. This book was released on 2010-05-06 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: Based on the work and contributions of 46 scientists, managers, and policymakers, Ecological Assessment of Selenium in the Aquatic Environment documents the state of the science and explores how to use this information when assessing and managing the environmental effects of Se. A focused discussion on the fate and effects of Se in aquatic ecosyste

Download or read book Selenium in the Environment written by W.T. Frankenberger Jr. and published by CRC Press. This book was released on 1994-06-10 with total page 477 pages. Available in PDF, EPUB and Kindle. Book excerpt: Discusses the biochemical and geological cycling of selenium (Se), its worldwide distribution, and the factors controlling its fate and transport within and between major environmental media, presenting a global assessment of selenium's complex environmental behaviour. The focus of this work is upon Se management and remediation strategies.

Download or read book Selenium Contamination in Water written by Pooja Devi and published by John Wiley & Sons. This book was released on 2021-05-12 with total page 436 pages. Available in PDF, EPUB and Kindle. Book excerpt: The contamination of environment and water resources by Selenium (Se) and its oxyanions from various sources are emerging contaminants of significant health and environmental concern. The primary sources include agricultural drainage water, mine drainage, residues from fossil fuels, thermoelectric power plants, oil refineries, and metal ores. Various methods and technologies have been developed which focus on the treatment of selenium-containing waters and wastewater. High concentrations of selenium in water cause various adverse impact to human health, such as carcinogenic, genotoxic, and cytotoxic effects. But in the lower concentrations, it is a useful constituent of the biological system. The range between toxicity and deficiency of selenium is minimal (40 to 400 μg per day), due to its dual nature. Selenium Contamination in Water contains the latest status and information on selenium’s origin, its chemistry and its toxicity to humans. The book represents a comprehensive and advanced reference book for students, researchers, practitioners, and policymakers in working in the field of metalloids, in particular selenium. A special emphasis is given on its geological distribution, monitoring techniques, and remedial technologies. As such, the authors critically analyze the various techniques used for the monitoring and removal of selenium from water. Featuring chapters arranged according to the major themes of the latest research, with specific case-studies from industrial experiences of selenium detection and removal, Selenium Contamination in Water will be particularly valued by researchers, practitioners, and policymakers in working in the field of metalloids including selenium.

Download or read book Effects of Selenium Supplementation in Cattle on Aquatic Ecosystems in Northern California written by Ben Norman and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Report on the Peer Consultation Workshop on Selenium Aquatic Toxicity and Bioaccumulation written by and published by . This book was released on 1998 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Environmental Technologies to Treat Selenium Pollution written by Piet Lens and published by IWA Publishing. This book was released on 2021-08-15 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: Selenium contamination of air, aquatic environments, soils and sediments is a serious environmental concern of increasing importance. Selenium has a paradoxical feature in bringing about health benefits under the prescribed level, but only a few fold increase in its concentration causes deleterious effects to flora and fauna, humans and the environment. Environmental Technologies to Treat Selenium Pollution: principles and engineering: - presents the fundamentals of the biogeochemical selenium cycle and which imbalances in this cycle result in pollution. - overviews chemical and biological technologies for successful treatment of selenium contaminated water, air, soils and sediments. - explores the recovery of value-added products from selenium laden waste streams, including biofortication and selenium based nanoparticles and quantum dots. This book may serve both as an advanced textbook for undergraduate and graduate students majoring in environmental sciences, technology or engineering as well as a handbook for tertiary educators, researchers, professionals and policy makers who conduct research and practices in selenium related fields. It is essential reading for consulting companies when dealing with selenium related environmental (bio)technologies.

Download or read book Aquatic Cycling of Selenium written by A. Dennis Lemly and published by . This book was released on 1987 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fish and Wildlife Leaflet written by and published by . This book was released on 1984 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Environmental Contaminants in Wildlife written by James P. Meador and published by CRC Press. This book was released on 1996-03-20 with total page 516 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many books have been written about the effects of toxic chemicals on wildlife, but none has focused on the practical question, "How much of a chemical in the tissues of an animal is harmful?" This book deals exclusively with that question. This comprehensive reference will certainly become the standard resource on the topic, offering authoritative and sound advice on many environmental contaminants. With chapters written by outstanding experts in their respective fields, this is not only a scholarly collection of discussions on different chemicals, but, for those who have the day-to-day task of evaluating the harm of environment contaminants to wildlife, this book will provide answers on, for example, how to interpret 1 ppm lead in the liver of a duck or fish. The authors explain the snags of interpreting data that are sometimes conflicting or insufficient, providing the reader with helpful advice on how to cope with such data. Each chapter reviews literature on a specific chemical, followed by a easy-to-understand summary providing technical guidance. For many years this book will remain the preeminent reference on how to interpret contaminant levels of organochlorine pesticides, PCBs, dioxins, PAHs, metals, selenium, and fluorides in wildlife.

Download or read book From Soil Aggregate to Watershed from California s Central Valley to the Salton Sea Agricultural Selenium Contamination Across Ecosystems Scales and Disciplines written by Matteo Francesco Kausch and published by . This book was released on 2013 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: Selenium (Se) is a trace element of great ecological importance whose environmental distribution is highly impacted by anthropogenic activity. In the 1980s, selenium was recognized as a major aquatic contaminant following widespread deformities and mortality among waterfowl hatchlings near the agricultural drainage evaporation ponds of the Kesterson Reservoir (CA, USA). Today, 400,000 km2 in the Western United States are threatened by agricultural selenium contamination, as are parts of Canada, Egypt, Israel, and Mexico. From the soil aggregate to the watershed, from the soils of the Central Valley to the sediments of the Salton Sea, and from Environmental Science to Policy and Management, in this dissertation I explore agricultural selenium contamination across scales, ecosystems, and disciplines. I begin with a review of the science, policy, and management of irrigation-induced selenium contamination in California, the heart of worldwide research on the issue. I then delve into the physical and biogeochemical mechanisms that control selenium reduction and mobility within the structured surface soils that are the source of contamination, using an aggregate-scale combined experimental and reactive transport modeling approach. Finally, I present a diagenetic model for selenium incorporation into the sediment of the Salton Sea, which has been receiving seleniferous agricultural drainage over the last 100 years. To extract lessons from the last 30 years of seleniferous drainage management and water quality regulation in California, I reviewed the history and current developments in science, policy, and management of irrigation-induced selenium contamination in California. Specifically, I evaluated improvements in the design of local attenuation methods and the development of programs for selenium load reductions at the regional scale. On the policy side, I assessed the site-specific water quality criteria under development for the San Francisco Bay-Delta in the context of previous regulation. This approach may be a landmark for future legislation on selenium in natural water bodies and I discussed challenges and opportunities in expanding it to other locations such as the Salton Sea. By combining proven management tools with the novel, site-specific policy approach, it may be possible to avoid future events of irrigation-induced selenium contamination. However, the majority of regional selenium load reductions in California were achieved by decreasing drainage volume rather than selenium concentrations. Thus, there appear to be opportunities for additional improvements through management practices that enhance selenium retention in source soils. Soil aggregates are the basic structural units of soil. They are mm- to cm-sized microporous assemblages of loosely bound soil particles, separated from one another by macropores. To elucidate how aggregate-scale transport and microbial reduction affect selenium retention in surface soils, I conducted a series of flow-through experiments utilizing artificial aggregate systems. These systems mimic the dual porosity of structured soils with an artificial soil aggregate (ID 2.5 cm) contained in a flow-through reactor cell. Aggregates were composed of either pure quartz sand or ferrihydrite-coated quartz sand inoculated with selenium reducing bacteria (Thauera selenatis or Enterobacter cloacae SLD1a-1). Oxic and anoxic conditions were compared, as well as various selenate (0.25-0.8 mM) and carbon source (0.3 and 1.2 mM) input concentrations. The presence of oxygen in the input solution significantly decreased selenium reduction, however, the detection of selenite in effluent samples indicates the occurrence of anoxic microzones within aggregates. Furthermore, I found that solid phase concentrations of reduced selenium increased towards the core of aggregates across all experimental conditions. A bulk model, ignoring intra-aggregate heterogeneity in reactions and transport, misrepresented the dynamics of the aggregate systems. To quantify the likely implications of these experimental results for soils with different degrees of aggregation, I formulated a general mechanistic framework for aggregate scale heterogeneity in selenium reduction. Specifically, I constructed a dynamic 2D model of selenium fate in single idealized aggregates, in which reactions were implemented with double-Monod rate equations coupled to the transport of pyruvate, O2, and Se-species (selenate, selenite, and elemental selenium). The spatial and temporal dynamics of the model were validated with the experimental data and predictive simulations were performed covering aggregate sizes between 1 and 2.5 cm diameters. Simulations predict that selenium retention scales with aggregate size. Depending on aeration conditions and the input concentrations of selenate and pyruvate, selenium retention was predicted to be 4-23 times higher in 2.5-cm-aggregates compared to 1-cm-aggregates. Under oxic conditions, aggregate size and pyruvate-concentrations were found to have a positive synergistic effect on selenium retention. Promoting soil aggregation on seleniferous agricultural soils may thus help decrease the impacts of selenium contaminated drainage on downstream aquatic ecosystems receiving it. One such ecosystem is California's largest inland water body, the Salton Sea, which is maintained entirely by agricultural runoff. Whereas elevated selenium concentrations are detected in the rivers feeding the lake, the lake's concentrations of dissolved selenium are low since most selenium entering the lake is sequestered in its sediment through microbial reduction. To predict the distribution profiles of selenium within the sediment and evaluate the factors driving them, I constructed a diagenetic model for reductive incorporation of selenate into Salton Sea sediment. The model predicts near surface (2 cm) sediment concentrations of solid phase selenium between 0.024 and 0.272 μmol/g depending on local reduction kinetics, and dissolved concentrations in the water column. This is in good agreement with the literature when considered in conjunction with the potential impact of bioturbation which according to exploratory simulations may lower near surface concentrations by around 25%. The range of modeled selenium concentrations in surface sediment crosses threshold values for which negative impacts on fish and waterfowl have been predicted or observed at other sites, suggesting that ecological impacts of selenium in the Salton Sea may depend locally on variation in the diagenetic factors here explored. This work presents agricultural selenium contamination as a complex problem that crosses ecosystems, scales, and disciplines. From a management perspective, the tension between dispersed non-point sources and hotspots where elevated selenium concentrations and sensitive aquatic ecosystems converge is difficult to address. Differences in biogeochemical conditions and trophic transfer within food webs render traditional regulatory approaches ineffective and force regulators to engage with the science of site-specific selenium transfer between ecological compartments. At the same time, gaps still exist in our mechanistic understanding of selenium's environmental cycling and in our integration of scientific knowledge across different ecosystems and scales. Centimeter scale heterogeneity in the biogeochemical conditions within source soils may fundamentally control selenium emissions across large agricultural areas and thus determine the selenium loading of rivers, lakes, and estuaries. Within aquatic environments receiving seleniferous drainage, the first few centimeters of surface sediment may control selenium exposure for entire food webs. Improved understanding at this level holds the potential to simultaneously reduce selenium emissions and respond more effectively to pollution where it occurs. In order to preserve sensitive habitat while also meeting agricultural drainage needs in seleniferous regions we must bridge the gaps between ecosystems, scales, and disciplines.

Download or read book Marine Pollution and Microbial Remediation written by Milind Mohan Naik and published by Springer. This book was released on 2016-09-23 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: Marine environment is the largest habitat covering approximately 70% of the total earth surface. Oceans are the main regulatory agent of earth’s climate and harbour a huge diversity of living organisms. Marine environment provide a unique ecological niche to different microbes which play a significant role in nutrient recycling as well as various environmental activities. However with rapid industrialization, urbanisation, ship trafficking and mining activities enormous amounts of waste including heavy metals, hydrocarbons, chemicals, dyes, organic load, agriculture waste, pesticides, antifoulants (e.g. tributyltin) and bacterial pathogens have accumulated in marine/estuarine environments over several decades and pose a serious threat to marine macro and micro biota and humans and therefore require special attention. However some natural marine microbes are known to possess diverse resistance mechanisms and degradation pathways to variety of toxic pollutants and these unique characteristics of marine/estuarine bacteria proved to be an ideal tool in bioremediation of contaminated marine and estuarine environmental sites. Reclamation of marine polluted environments using marine microbes has been found to be effective, affordable and ecofriendly technological solution over conventional physical and chemical methods. Objective of this book is focus on marine pollution and application of marine microorganisms in cost effective and ecofriendly methods of pollution abatement.

Download or read book Selenium in the Environment and Human Health written by Gary S. Banuelos and published by CRC Press. This book was released on 2013-11-29 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: Selenium is arguably the naturally occurring trace element of greatest concern worldwide. In excessive amounts it can lead to toxicosis and teratogenesis in animals, while the impact of selenium deficiency can be even more significant. Contributors from 22 countries explored the connections and inter-relationships between selenium in the environmen

Download or read book The Bioaccumulation of Selenium in Aquatic Ecosystems written by Richard Scott Ogle and published by . This book was released on 1996 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Selected Water Resources Abstracts written by and published by . This book was released on 1991 with total page 962 pages. Available in PDF, EPUB and Kindle. Book excerpt: