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Coupling Of The Biogeochemical Cycles Of Uranium And Manganese
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Book Synopsis Coupling of the Biogeochemical Cycles of Uranium and Manganese by : Zimeng Wang
Download or read book Coupling of the Biogeochemical Cycles of Uranium and Manganese written by Zimeng Wang and published by . This book was released on 2013 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: Organic electron donor stimulated microbial reduction of U(VI) to U(IV) has been proposed as a strategy for the in situ immobilization of uranium contamination in the subsurface. The success of the bioremediation of uranium relies on the stability of the reduced U(IV) species (e.g., UO2) with respect to reoxidation and/or remobilization under groundwater conditions. Manganese is present at appreciable concentrations at several uranium-contaminated sites, and the redox cycling of manganese may significantly impact uranium's fate and transport. The biogeochemical coupling of uranium and manganese involves multiple interaction pathways that occur in the aqueous phase as well as at solid-water interfaces. A mechanistic and quantitative understanding of these processes is needed to establish input parameters for reactive transport models and to enable decision-making for remediation strategies. Coupling of the biogeochemical cycles of uranium and manganese involves various interfacial reactions that occur between UO2 and Mn species of various oxidation states (+IV, +III and +II). This study investigated the physical and chemical factors controlling the interactions between uraninite (UO2) and manganese oxide (MnO2), which are both poorly soluble minerals. A multi-chamber reactor with a permeable membrane was used to simulate a barrier for direct contact of the two solids. The results suggested that an effective redox reaction between UO2 and MnO2 requires physical contact. Continuously-stirred tank reactors (CSTRs) were used to evaluate the dissolution rates of UO2. MnO2 dramatically promoted UO2 dissolution, but the degree of promotion leveled off once the MnO2:UO2 ratio exceeded a critical value. The fate of uranium and manganese after the reaction was investigated by chemical extraction and X-ray absorption spectroscopy (XAS). Substantial amounts of U(VI) and Mn(II) were retained on MnO2 surfaces, and the fate of Mn products may involve Mn(III) phases. A conceptual model was proposed to describe the oxidation of UO2 by MnO2, which is potentially applicable to other environmental redox processes involving two poorly soluble minerals. Although MnO2 can oxidize UO2, the U(VI) produced may not be readily released into the aqueous phase due to its strong adsorption to MnO2. This study integrated batch experiments of U(VI) adsorption to synthetic and biogenic MnO2, surface complexation modeling (SCM), and molecular-scale characterization of adsorbed U(VI) with extended X-ray absorption fine structure (EXAFS) spectroscopy. The surface complexation model incorporated the surface complexes that are consistent with EXAFS analysis, and it could successfully simulate adsorption results over a broad range of pH and dissolved inorganic carbon concentrations. The description of bidentate surface complexes, which are widely observed for contaminant adsorption to metal oxides including the U(VI)-MnO2 system, is a subject with considerable confusion in the literature. Consequently, a critical review was prepared that discussed the theoretical and practical aspects of mass action expressions for bidentate surface complexation reactions. Suggestions were provided for handling bidentate reactions and publishing results without ambiguity or confusion. The effects of soluble Mn species (+III and +II oxidation states) on UO2 dissolution were also investigated. Soluble Mn(III) species were recently identified as important intermediates in Mn biogeochemical cycling. This study evaluated the kinetics of oxidative UO2 dissolution by soluble Mn(III) stabilized by pyrophosphate (PP) and desferrioxamine B (DFOB). The Mn(III)-PP complex was a potent oxidant that induced rapid UO2 dissolution at a rate higher than by a comparable concentration of dissolved O2. However, the Mn(III)-DFOB complex was not able to induce oxidative dissolution of UO2. The potency of Mn(III) with respect to oxidizing UO2 was governed by the identity of the ligand and water chemistry parameters that affect the speciation of the Mn(III). The effect of soluble Mn(II) was more complicated than that of non-redox-active divalent cations (e.g., Ca and Zn). Under anoxic conditions, Mn(II) inhibited UO2 dissolution, which may be attributed to both Mn(II) adsorption to the UO2 surface and precipitation of MnCO3, both of which could decrease the exposure of U(IV) surface sites. In contrast to the anoxic conditions, Mn(II) promoted UO2 dissolution under oxidizing condition. The promotional effect was likely due to Mn redox cycling in which oxidized forms of Mn species were (re)generated as oxidants of UO2 that were more potent than O2. The observed effects of soluble Mn(II, III) species on UO2 dissolution highlighted the need to consider Mn redox intermediates in facilitating electron transfer processes in subsurface biogeochemical cycles.
Book Synopsis Water-resources Investigations Report by :
Download or read book Water-resources Investigations Report written by and published by . This book was released on 1991 with total page 756 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis U.S. Geological Survey Toxic Substances Hydrology Program by : Gail E. Mallard
Download or read book U.S. Geological Survey Toxic Substances Hydrology Program written by Gail E. Mallard and published by . This book was released on 1992 with total page 748 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Treatise on Estuarine and Coastal Science by :
Download or read book Treatise on Estuarine and Coastal Science written by and published by Academic Press. This book was released on 2012-03-06 with total page 4604 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study of estuaries and coasts has seen enormous growth in recent years, since changes in these areas have a large effect on the food chain, as well as on the physics and chemistry of the ocean. As the coasts and river banks around the world become more densely populated, the pressure on these ecosystems intensifies, putting a new focus on environmental, socio-economic and policy issues. Written by a team of international expert scientists, under the guidance of Chief Editors Eric Wolanski and Donald McClusky, the Treatise on Estuarine and Coastal Science, Ten Volume Set examines topics in depth, and aims to provide a comprehensive scientific resource for all professionals and students in the area of estuarine and coastal science Most up-to-date reference for system-based coastal and estuarine science and management, from the inland watershed to the ocean shelf Chief editors have assembled a world-class team of volume editors and contributing authors Approach focuses on the physical, biological, chemistry, ecosystem, human, ecological and economics processes, to show how to best use multidisciplinary science to ensure earth's sustainability Provides a comprehensive scientific resource for all professionals and students in the area of estuarine and coastal science Features up-to-date chapters covering a full range of topics
Book Synopsis Handbook of Metal-Microbe Interactions and Bioremediation by : Surajit Das
Download or read book Handbook of Metal-Microbe Interactions and Bioremediation written by Surajit Das and published by CRC Press. This book was released on 2017-04-07 with total page 813 pages. Available in PDF, EPUB and Kindle. Book excerpt: Around the World, metal pollution is a major problem. Conventional practices of toxic metal removal can be ineffective and/or expensive, delaying and exacerbating the crisis. Those communities dealing with contamination must be aware of the fundamentals advances of microbe-mediated metal removal practices because these methods can be easily used and require less remedial intervention. This book describes innovations and efficient applications for metal bioremediation for environments polluted by metal contaminates.
Book Synopsis The Natural Environment and the Biogeochemical Cycles by :
Download or read book The Natural Environment and the Biogeochemical Cycles written by and published by Springer. This book was released on 2013-06-05 with total page 201 pages. Available in PDF, EPUB and Kindle. Book excerpt: An important purpose of The Handbook of Environmental Chemi- stry is to aid the understanding of distribution and chemi- cal reaction processes which occur in the environment. It is designed to serve as an important source forenvironmental scientists and decision-makers in industry, governmental and regulatory bodies. Volume 1F is dedicated to geosphere interactions, environmental inorganic geochemistry and the evolution of matter and energy. Contents: "Geosphere Inter- actions on a Convecting Planet: Mixing and Separation" by W.S. Fyfe; "Environmental Inorganic Chemistry of the Conti- nental Crust" by H. Puchelt; "Evolution ofMatter and Ener- gy" by M. Taube.
Book Synopsis Fungi in Biogeochemical Cycles by : Geoffrey Michael Gadd
Download or read book Fungi in Biogeochemical Cycles written by Geoffrey Michael Gadd and published by Cambridge University Press. This book was released on 2006-05-04 with total page 504 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book promotes further understanding of the contribution that fungi make to the biogeochemical cycling of elements, the chemical and biological mechanisms involved, and their environmental and biotechnological significance.
Book Synopsis Experiments in Soil Biology and Biochemistry by : Fran Russell & Danni Gilmore
Download or read book Experiments in Soil Biology and Biochemistry written by Fran Russell & Danni Gilmore and published by Scientific e-Resources. This book was released on 2018-08-14 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soil science is the study of soil as a natural resource on the surface of the Earth including soil formation, classification and mapping; physical, chemical, biological, and fertility properties of soils; and these properties in relation to the use and management of soils. Soil biology is the study of microbial and faunal activity and ecology in soil. Soil life, soil biota and soil fauna are collective terms that encompasses all organisms that spend a significant portion of their life cycle within a soil profile, or at the soil-litter interface. Soils are rich ecosystems, composed of both living and non-living matter with a multitude of interaction between them. Soils play an important role in all of our natural ecological cycles. They also provide benefits through their contribution in a number of additional processes, called ecosystem services. These services range from waste decomposition to acting as a water filtration system to degrading environmental contaminants. Soil biochemistry is one of the branches of soil science dealing with the formation and decomposition of soil organic matter, biochemical reactions of carbon, nitrogen, phosphorus, sulfur, metals and xenobiotic in soils, and biochemistry of the plant-root rhizosphere. The book will suit to the needs of students, teachers, scholars and general readers.
Book Synopsis Large Igneous Provinces by : Richard E. Ernst
Download or read book Large Igneous Provinces written by Richard E. Ernst and published by John Wiley & Sons. This book was released on 2021-02-09 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is Open Access. A digital copy can be downloaded for free from Wiley Online Library. Exploring the links between Large Igneous Provinces and dramatic environmental impact An emerging consensus suggests that Large Igneous Provinces (LIPs) and Silicic LIPs (SLIPs) are a significant driver of dramatic global environmental and biological changes, including mass extinctions. Environmental changes caused by LIPs and SLIPs include rapid global warming, global cooling ('Snowball Earth'), oceanic anoxia events, mercury poisoning, atmospheric and oceanic acidification, and sea level changes. Continued research to characterize the effects of these extremely large and typically short duration igneous events on atmospheric and oceanic chemistry through Earth history can provide lessons for understanding and mitigating modern climate change. Large Igneous Provinces: A Driver of Global Environmental and Biotic Changes describes the interactions between the effects of LIPs and other drivers of climatic change, the limits of the LIP effect, and the atmospheric and oceanic consequences of LIPs in significant environmental events. Volume highlights include: Temporal record of large igneous provinces (LIPs) Environmental impacts of LIP emplacement Precambrian, Proterozoic, and Phanerozoic case histories Links between geochemical proxies and the LIP record Alternative causes for environmental change Key parameters related to LIPs and SLIPs for use in environmental change modelling Role of LIPs in Permo-Triassic, Triassic-Jurassic, and other mass extinction events The American Geophysical Union promotes discovery in Earth and space science for the benefit of humanity. Its publications disseminate scientific knowledge and provide resources for researchers, students, and professionals.
Book Synopsis Reaction Mechanisms in Environmental Engineering by : James G. Speight
Download or read book Reaction Mechanisms in Environmental Engineering written by James G. Speight and published by Butterworth-Heinemann. This book was released on 2018-08-13 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reaction Mechanisms in Environmental Engineering: Analysis and Prediction describes the principles that govern chemical reactivity and demonstrates how these principles are used to yield more accurate predictions. The book will help users increase accuracy in analyzing and predicting the speed of pollutant conversion in engineered systems, such as water and wastewater treatment plants, or in natural systems, such as lakes and aquifers receiving industrial pollution. Using examples from air, water and soil, the book begins with a clear exposition of the properties of environmental and inorganic organic chemicals that is followed by partitioning and sorption processes and sorption and transformation processes. Kinetic principles are used to calculate or estimate the pollutants' half-lives, while physical-chemical properties of organic pollutants are used to estimate transformation mechanisms and rates. The book emphasizes how to develop an understanding of how physico-chemical and structural properties relate to transformations of organic pollutants. Offers a one-stop source for analyzing and predicting the speed of organic and inorganic reaction mechanisms for air, water and soil Provides the tools and methods for increased accuracy in analyzing and predicting the speed of pollutant conversion in engineered systems Uses kinetic principles and the physical-chemical properties of organic pollutants to estimate transformation mechanisms and rates
Book Synopsis Environmental Microbiology: Fundamentals and Applications by : Jean-Claude Bertrand
Download or read book Environmental Microbiology: Fundamentals and Applications written by Jean-Claude Bertrand and published by Springer. This book was released on 2015-01-26 with total page 933 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a treatise on microbial ecology that covers traditional and cutting-edge issues in the ecology of microbes in the biosphere. It emphasizes on study tools, microbial taxonomy and the fundamentals of microbial activities and interactions within their communities and environment as well as on the related food web dynamics and biogeochemical cycling. The work exceeds the traditional domain of microbial ecology by revisiting the evolution of cellular prokaryotes and eukaryotes and stressing the general principles of ecology. The overview of the topics, authored by more than 80 specialists, is one of the broadest in the field of environmental microbiology. The overview of the topics, authored by more than 80 specialists, is one of the broadest in the field of environmental microbiology.
Book Synopsis Biomineralization in Lower Plants and Animals by : Barry S. C. Leadbeater
Download or read book Biomineralization in Lower Plants and Animals written by Barry S. C. Leadbeater and published by . This book was released on 1986 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Monera and Protista Kingdoms contain species that form many different mineral types by varying processes at different cellular locations. This book identifies the underlying trends and processes common to each group. It discusses the controls, products, and functional significance of biomineralization for such simple organisms as algae, protozoans, bacteria, and lichens--information useful to botanists, zoologists, paleontologists, and research chemists.
Book Synopsis Biogeochemistry by : W.H. Schlesinger
Download or read book Biogeochemistry written by W.H. Schlesinger and published by Elsevier. This book was released on 2005-06-08 with total page 760 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Treatise on Geochemistry is the first work providing a comprehensive, integrated summary of the present state of geochemistry. It deals with all the major subjects in the field, ranging from the chemistry of the solar system to environmental geochemistry. The Treatise on Geochemistry has drawn on the expertise of outstanding scientists throughout the world, creating the reference work in geochemistry for the next decade. Each volume consists of fifteen to twenty-five chapters written by recognized authorities in their fields, and chosen by the Volume Editors in consultation with the Executive Editors. Particular emphasis has been placed on integrating the subject matter of the individual chapters and volumes. Elsevier also offers the Treatise on Geochemistry in electronic format via the online platform ScienceDirect, the most comprehensive database of academic research on the Internet today, enhanced by a suite of sophisticated linking, searching and retrieval tools.
Book Synopsis Geomicrobiology by : Henry Lutz Ehrlich
Download or read book Geomicrobiology written by Henry Lutz Ehrlich and published by CRC Press. This book was released on 2008-12-22 with total page 630 pages. Available in PDF, EPUB and Kindle. Book excerpt: Uncovers the Key Role Microbes Play in the Transformation of Oxidizable and Reducible MineralsMany areas of geomicrobial processes are receiving serious attention from microbiologists, specifically the role microbes play in the formation and degradation of minerals and fossil fuels and elemental cycling. Most notably, the latest research finds that
Book Synopsis Surface Complexation Modeling by : Athanasios K. Karamalidis
Download or read book Surface Complexation Modeling written by Athanasios K. Karamalidis and published by John Wiley & Sons. This book was released on 2011-02-14 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a description of the generalized two layer surface complexation model, data treatment procedures, and thermodynamic constants for sorption of metal cations and anions on gibbsite, the most common form of aluminum oxide found in nature and one of the most abundant minerals in soils, sediments, and natural waters. The book provides a synopsis of aluminum oxide forms and a clearly defined nomenclature. Compilations of available data for sorption of metal cations and anions on gibbsite are presented, and the results of surface complexation model fitting of these data are given. The consistency of the thermodynamic surface complexation constants extracted from the data is examined through development of linear free energy relationships which are also used to predict thermodynamic constants for ions for which insufficient data are available to extract constants. The book concludes with a comparison of constants extracted from data for sorption on gibbsite with those determined previously for hydrous ferric oxide (HFO), hydrous manganese oxide (HMO), and goethite. The overall objective of this book is the development and presentation of an internally consistent thermodynamic database for sorption of inorganic cations and anions on gibbsite, an abundant and reactive mineral in soils, sediments, and aquatic systems. Its surface has a high affinity for sorption of metal cations and anions, including radionuclides. The gibbsite database will enable simulation and prediction of the influence of sorption on the fate of these chemical species in natural systems and treatment processes in which aluminum oxides are abundant. It thus will help to advance the practical application of surface complexation modeling.
Book Synopsis Interactions of Microorganisms with Radionuclides by : M.J. Keith-Roach
Download or read book Interactions of Microorganisms with Radionuclides written by M.J. Keith-Roach and published by Elsevier. This book was released on 2002-04-22 with total page 409 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many environmental processes are influenced, if not controlled, by microbial action and it is becoming increasingly important to develop an understanding of microbial roles in geochemistry. This book brings together state of the art research into microbiological processes and the extent to which they affect or can be used to control radioactive elements. The basic principles and fundamental mechanisms by which microbes and radionuclides interact are outlined, the methodology described, potential microbial influences on waste repositories examined, direct and indirect effects on transport both on local and global scales considered and potential technological applications identified. The book is directed towards advanced undergraduate students, postgraduates and researchers in the areas of environmental radioactivity, environmental microbiology, biotechnology and radioactive waste management. It will also be of interest to regulators, policy makers and non-governmental organisations. This novel and timely book offers a fully integrated approach to a topical international issue.
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1966-03 with total page 1544 pages. Available in PDF, EPUB and Kindle. Book excerpt:
