Download or read book The Effects of Bicarbonate and Mineral Surfaces on Uranium Immobilization Under Anaerobic Conditions written by Luis A. Jurado and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: For four decades, from 1940 through 1980, the U.S. Department of Energy (DoE) extensively mined and processed uranium at various sites. As a result, widespread uranium contamination exists in subsurface sediments and aquifers. In subsurface environments, uranium primarily exists as U(VI) or U(IV), oxidized and reduced species, respectively. U(VI) is highly soluble and toxic, U(IV), while relatively toxic, is insoluble which greatly reduces its exposure pathways. We seek to examine the role of ferric iron on U(VI) reduction by adsorbing U(VI) onto ferric and non-ferric mineral surfaces in the presence of a reductant. Further, we seek to understand the role that NaHCO3, a natural groundwater buffer, has in the reductive geochemical transformations of U(VI) adsorbed on ferric and non-ferric mineral surfaces. Bench top studies were performed using 100 uM U(VI) and the reductant AHQDS, in the presence and absence of Fe-Gel (amorphous ferric oxyhydroxide) and gamma-Al2O3. In the presence of a HEPES buffer at pH 8, results demonstrate direct homogeneous reduction in several hours in the absence of Fe-Gel or gamma-Al2O3, and reduction within a 48-hour period in the presence Fe-Gel or gamma-Al2O3. While adsorbed to both ferric and non-ferric mineral surfaces, U(VI) reduction is inhibited. U(VI) reduction in the presence of NaHCO3 buffer also inhibits U(VI) reduction.

Download or read book FINAL REPORT Biogeochemistry of Uranium Under Reducing and Re oxidizing Conditions written by James Amonette and published by . This book was released on 2005 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our understanding of subsurface microbiology is hindered by the inaccessibility of this environment, particularly when the hydrogeologic medium is contaminated with toxic substances. Research in our labs indicated that the composition of the growth medium (e.g., bicarbonate complexation of U(VI)) and the underlying mineral phase (e.g., hematite) significantly affects the rate and extent of U(VI) reduction and immobilization through a variety of effects. Our research was aimed at elucidating those effects to a much greater extent, while exploring the potential for U(IV) reoxidation and subsequent re-mobilization, which also appears to depend on the mineral phases present in the system. In situ coupons with a variety of mineral phases were placed in monitoring wells at the NABIR FRC. These coupons showed that the mineral phase composition significantly affected the resulting attached phase microbial community. Our comparative use of both batch and open flow reactors (more representative of field conditions) indicates that hydrodynamics and continual influx of substrate and contaminants can also yield significantly different results than those obtained with closed serum bottles. To this end, the following overall experimental hypothesis tested was the following: On a mineral surface under anaerobic conditions, accumulations of secondary inorganic precipitates are controlled by a) the bacteria associated with the mineral surface, b) the electron acceptors available for anaerobic bacterial respiration, and c) local hydrodynamics and pH buffers govern micro- and meso-scale interaction of U in the presence of electron donors and acceptors, and nutrients.

Download or read book FINAL REPORT Biogeochemistry of Uranium Under Reducing and Re oxidizing Conditions written by and published by . This book was released on 2005 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our understanding of subsurface microbiology is hindered by the inaccessibility of this environment, particularly when the hydrogeologic medium is contaminated with toxic substances. Research in our labs indicated that the composition of the growth medium (e.g., bicarbonate complexation of U(VI)) and the underlying mineral phase (e.g., hematite) significantly affects the rate and extent of U(VI) reduction and immobilization through a variety of effects. Our research was aimed at elucidating those effects to a much greater extent, while exploring the potential for U(IV) reoxidation and subsequent re-mobilization, which also appears to depend on the mineral phases present in the system. In situ coupons with a variety of mineral phases were placed in monitoring wells at the NABIR FRC. These coupons showed that the mineral phase composition significantly affected the resulting attached phase microbial community. Our comparative use of both batch and open flow reactors (more representative of field conditions) indicates that hydrodynamics and continual influx of substrate and contaminants can also yield significantly different results than those obtained with closed serum bottles. To this end, the following overall experimental hypothesis tested was the following: On a mineral surface under anaerobic conditions, accumulations of secondary inorganic precipitates are controlled by a) the bacteria associated with the mineral surface, b) the electron acceptors available for anaerobic bacterial respiration, and c) local hydrodynamics and pH buffers govern micro- and meso-scale interaction of U in the presence of electron donors and acceptors, and nutrients.

Download or read book The Microbiology of Nuclear Waste Disposal written by Jonathan R. Lloyd and published by Elsevier. This book was released on 2020-10-22 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Microbiology of Nuclear Waste Disposal is a state-of-the-art reference featuring contributions focusing on the impact of microbes on the safe long-term disposal of nuclear waste. This book is the first to cover this important emerging topic, and is written for a wide audience encompassing regulators, implementers, academics, and other stakeholders. The book is also of interest to those working on the wider exploitation of the subsurface, such as bioremediation, carbon capture and storage, geothermal energy, and water quality. Planning for suitable facilities in the U.S., Europe, and Asia has been based mainly on knowledge from the geological and physical sciences. However, recent studies have shown that microbial life can proliferate in the inhospitable environments associated with radioactive waste disposal, and can control the long-term fate of nuclear materials. This can have beneficial and damaging impacts, which need to be quantified. - Encompasses expertise from both the bio and geo disciplines, aiming to foster important collaborations across this disciplinary divide - Includes reviews and research papers from leading groups in the field - Provides helpful guidance in light of plans progressing worldwide for geological disposal facilities - Includes timely research for planning and safety case development

Download or read book Natural Attenuation for Groundwater Remediation written by Commission on Geosciences, Environment, and Resources and published by National Academies Press. This book was released on 2000-08-31 with total page 289 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the past decade, officials responsible for clean-up of contaminated groundwater have increasingly turned to natural attenuation-essentially allowing naturally occurring processes to reduce the toxic potential of contaminants-versus engineered solutions. This saves both money and headaches. To the people in surrounding communities, though, it can appear that clean-up officials are simply walking away from contaminated sites. When is natural attenuation the appropriate approach to a clean-up? This book presents the consensus of a diverse committee, informed by the views of researchers, regulators, and community activists. The committee reviews the likely effectiveness of natural attenuation with different classes of contaminants-and describes how to evaluate the "footprints" of natural attenuation at a site to determine whether natural processes will provide adequate clean-up. Included are recommendations for regulatory change. The committee emphasizes the importance of the public's belief and attitudes toward remediation and provides guidance on involving community stakeholders throughout the clean-up process. The book explores how contamination occurs, explaining concepts and terms, and includes case studies from the Hanford nuclear site, military bases, as well as other sites. It provides historical background and important data on clean-up processes and goes on to offer critical reviews of 14 published protocols for evaluating natural attenuation.

Download or read book Phosphate in Soils written by H. Magdi Selim and published by CRC Press. This book was released on 2018-10-08 with total page 381 pages. Available in PDF, EPUB and Kindle. Book excerpt: Edited by One of the Best Specialists in Soil Science Recent studies reveal that Phosphorus (P) in the form of phosphate, a macronutrient essential for plant growth, and crop yields can influence the bioavailability, retention, and mobility of trace elements, metal(loid)s, and radio nuclides in soils. When this occurs, phosphates can affect the dynamics of heavy metals and influence soil characteristics, impacting soil mobility and toxicity. Phosphate in Soils: Interaction with Micronutrients, Radionuclides and Heavy Metals utilizes the latest research to emphasize the role that phosphate plays in enhancing or reducing the mobility of heavy metals in soil, and the soil-water-plant environment. It provides an in-depth understanding of each heavy metal species, and expands on phosphate interactions in geological material. Composed of 12 chapters, this text: Provides an overview of the reactions of metal(loid)s and common P compounds that are used as fertilizer in soils Emphasizes the effect of phosphorus on copper and zinc adsorption in acid soils Discusses findings on the influence of phosphate compounds on speciation, mobility, and bioavailability of heavy metals in soils as well as the role of phosphates on in situ and phytoremediation of heavy metals for contaminated soils Places emphasis on the influence of phosphate on various heavy metals species in soils, and their solubility/mobility and availability Provides extensive information on testing various high phosphate materials for remediation of heavy metal, micronutrients, and radionuclides contaminated sites Explores the reactivity of heavy metals, micronutrients and radionuclides elements in several soils Presents a case study illustrating various remediation efforts of acidic soils and remediation of Cu, Zn, and lead (Pb) contaminated soils around nonferrous industrial plants Emphasizes the significance of common ions (cations and anions) on phosphate mobility and sorption in soils, and more The author includes analytical and numerical solutions along with hands-on applications, and addresses other topics that include the transport and sorption modeling of heavy metals in the presence of phosphate at different scales in the vadose zone.

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 Heavy Metals in the Environment written by Edgardo R. Donati and published by CRC Press. This book was released on 2018-01-03 with total page 247 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book serves as a knowledge bank for researchers and graduate students in microbiology, chemistry, and environmental sciences, among others. It focuses on heavy metal in the environment and describes methodologies to immobilize and mobilize heavy metals. It also provides case studies which may be of particular interest to persons in industry.

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.

Download or read book Iron Oxides written by Damien Faivre and published by John Wiley & Sons. This book was released on 2016-08-08 with total page 626 pages. Available in PDF, EPUB and Kindle. Book excerpt: Alle relevanten Informationen zu Eisenoxiden, von der Struktur und Transformation über Charakterisierungsverfahren bis hin zu den neuesten AnwendungEN. Ein Muss für alle, die in dem Fachgebiet arbeiten.

Download or read book Surface Complexation Modelling written by Johannes Lutzenkirchen and published by Elsevier. This book was released on 2006-09-02 with total page 653 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface Complexation Modelling deals with various aspects associate to the modelling of solutes adsorption from of solutes from aqueous solutions to minerals. The individual contributions cover fundamental aspects and applications. Applications cover case studies and present consistent surface complexation parameter sets. The model approaches range from simplistic to mechanistic. More fundamental contributions address underlying phenomena or stress the opportunities of modern computational methods. Several mineral systems are covered, including goethite, gibbsite, clay minerals etc.Surface Complexation Modelling presents the state-of-the-art of surface complexation modelling and suggests ideas for further model development. A number of chapters are authored by scientists working on nuclear waste storage, where the retention of radionuclides contributes to preventing radionuclide migration from the repository to the biosphere. Other contributions come from soil and environmental chemists with an interest in reactive transport of pollutants in soils or aquifers. - Covering a wide range of disciplines - Bringing together contributions from experts in the field - Providing a balance between the theoretical and applied aspects

Download or read book Phosphorus Polluter and Resource of the Future written by Christian Schaum and published by IWA Publishing. This book was released on 2018-03-15 with total page 592 pages. Available in PDF, EPUB and Kindle. Book excerpt: This comprehensive book provides an up-to-date and international approach that addresses the Motivations, Technologies and Assessment of the Elimination and Recovery of Phosphorus from Wastewater. This book is part of the Integrated Environmental Technology Series.

Download or read book Sediments and Toxic Substances written by Wolfgang Calmano and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 337 pages. Available in PDF, EPUB and Kindle. Book excerpt: In modern sediment research on contaminants five aspects are discussed which, in an overlapping succession, also reflect develop ment of knowledge on particle-associated pollutants during the past twenty-five years: (1) identification of sources and their distribution; (2) evaluation of solid/solution relations; (3) study of transfer mecha nisms to biological systems; (4) assessment of environment impact; and (5) selection and further development of remedial measures, in par ticular, of dredged materials. Scientific research and practical develop ment are still expanding in all these individual aspects. Similar to other waste materials, management of contaminated sed iments requires a holistic approach. This means that assessment of biogeochemical reactions, interfacial processes and transfer mecha nisms as well as the prognosis of long-term borderline conditions, in particular of capacity-controlling properties, should be an integrated part of the wider management scheme, i.e., the analytical and experi mental parameters should always be related to potential remediation options for a specific sediment problem. The underlying coordinated project, which was funded by the German Federal Ministry for Science and Technology (now the Federal Ministry for Education, Science, Research and Technology) provided excellent opportunities for multidisciplinary effort, bringing together biologists, chemists, engineers, geologists and other researchers. During its active phase, the group attracted much interest nationally and internationally. The group members highly appreciate the manifold contacts and invitations during the past five years.

Download or read book Trace Elements in Waterlogged Soils and Sediments written by Jörg Rinklebe and published by CRC Press. This book was released on 2016-08-19 with total page 419 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many wetlands around the world act as sinks for pollutants, in particular for trace elements. In comparison to terrestrial environments, wetlands are still far less studied. A collaborative effort among world experts, this book brings the current knowledge concerning trace elements in temporary waterlogged soils and sediments together. It discusses factors controlling the dynamics and release kinetics of trace elements and their underlying biogeochemical processes. It also discusses current technologies for remediating sites contaminated with trace metals, and the role of bioavailability in risk assessment and regulatory decision making. This book is intended for professionals around the world in disciplines related to contaminant bioavailability in aquatic organisms, contaminant fate and transport, remediation technologies, and risk assessment of aquatic and wetland ecosystems.

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 Negative Emissions Technologies and Reliable Sequestration written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2019-04-08 with total page 511 pages. Available in PDF, EPUB and Kindle. Book excerpt: To achieve goals for climate and economic growth, "negative emissions technologies" (NETs) that remove and sequester carbon dioxide from the air will need to play a significant role in mitigating climate change. Unlike carbon capture and storage technologies that remove carbon dioxide emissions directly from large point sources such as coal power plants, NETs remove carbon dioxide directly from the atmosphere or enhance natural carbon sinks. Storing the carbon dioxide from NETs has the same impact on the atmosphere and climate as simultaneously preventing an equal amount of carbon dioxide from being emitted. Recent analyses found that deploying NETs may be less expensive and less disruptive than reducing some emissions, such as a substantial portion of agricultural and land-use emissions and some transportation emissions. In 2015, the National Academies published Climate Intervention: Carbon Dioxide Removal and Reliable Sequestration, which described and initially assessed NETs and sequestration technologies. This report acknowledged the relative paucity of research on NETs and recommended development of a research agenda that covers all aspects of NETs from fundamental science to full-scale deployment. To address this need, Negative Emissions Technologies and Reliable Sequestration: A Research Agenda assesses the benefits, risks, and "sustainable scale potential" for NETs and sequestration. This report also defines the essential components of a research and development program, including its estimated costs and potential impact.

Download or read book Humic Substances in Soil Sediment and Water written by George R. Aiken and published by . This book was released on 1991-11-01 with total page 708 pages. Available in PDF, EPUB and Kindle. Book excerpt: