Download or read book The chemical speciation of technetium in the environment written by S. T. Sparkes and published by . This book was released on 1987 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Investigation Into the Chemical Speciation of Technetium in the Environment written by S. Nicholson and published by . This book was released on 1990 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Chemical Speciation of Technetium in the Environment written by S. T. Sparkes and published by . This book was released on 1987 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Technetium in the Environment written by G. Desmet and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the discovery of technetium (in 1937, by Perrier and Segre), technetium-99 and technetium-99m have become most familiar in the specialised literature, the behaviour of the former being of concern regarding its health impact, the latter having been used intensively in medical tests for many years. The knowledge of the characteristics and behaviour of this element in nature is currently increasing exponentially. It has become clear, however, that there is still a serious shortage of information needed to assess properly its burden and impact on man and his environment. Technetium may indeed be released from nuclear installations or as a waste product from medical applications. It is generally considered to be highly mobile as the anion TcOi, but it is also suspected to be readily reduced in soils and metabolised in living beings into lower oxidation states. The seminar was planned to analyse thoroughly the experimental results obtained up to now and to make recommendations of specific issues requiring further research. This book presents the papers of the different sessions in the order of presentation, and the conclusions drawn by three discussion groups which dealt separately with: problems of sources and distribution of man-made technetium and its radiological consequences; the chemical behaviour of technetium in different ecosystems; biochemical reactions and binding with macromolecules in various life systems. vi Preface The editors, together with the Programme Committee of the Seminar, wish to express their gratitude to the chairmen of the different sessions for their summary of the group discussions.
Download or read book Chemical speciation of long lived radionuclide technetium 99 and its environmental behaviour written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Radionuclides in the Environment written by Clemens Walther and published by Springer. This book was released on 2015-10-30 with total page 277 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides extensive and comprehensive information to researchers and academicians who are interested in radionuclide contamination, its sources and environmental impact. It is also useful for graduate and undergraduate students specializing in radioactive-waste disposal and its impact on natural as well as manmade environments. A number of sites are affected by large legacies of waste from the mining and processing of radioactive minerals. Over recent decades, several hundred radioactive isotopes (radioisotopes) of natural elements have been produced artificially, including 90Sr, 137Cs and 131I. Several other anthropogenic radioactive elements have also been produced in large quantities, for example technetium, neptunium, plutonium and americium, although plutonium does occur naturally in trace amounts in uranium ores. The deposition of radionuclides on vegetation and soil, as well as the uptake from polluted aquifers (root uptake or irrigation) are the initial point for their transfer into the terrestrial environment and into food chains. There are two principal deposition processes for the removal of pollutants from the atmosphere: dry deposition is the direct transfer through absorption of gases and particles by natural surfaces, such as vegetation, whereas showery or wet deposition is the transport of a substance from the atmosphere to the ground by snow, hail or rain. Once deposited on any vegetation, radionuclides are removed from plants by the airstre am and rain, either through percolation or by cuticular scratch. The increase in biomass during plant growth does not cause a loss of activity, but it does lead to a decrease in activity concentration due to effective dilution. There is also systemic transport (translocation) of radionuclides within the plant subsequent to foliar uptake, leading the transfer of chemical components to other parts of the plant that have not been contaminated directly.
Download or read book Chemical Speciation in the Environment written by A. M. Ure and published by John Wiley & Sons. This book was released on 2008-04-15 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt: Considerable recent research has focused on the topic of chemical speciation in the environment. It is increasingly realised that the distribution, mobility and biological availability of chemical elements depend not simply on their concentrations but, critically, on the forms in which they occur in natural systems. Continuing developments in analytical chemistry have made speciation practicable even where analytes are present at trace levels (as is often the case in natural samples). In the second edition of this book, the expertise of scientists involved in chemical speciation in various fields have been brought together to provide an overview of the current status of speciation science and indicate how the field may develop in the future.
Download or read book Radionuclides in the Environment written by Clemens Walther and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides extensive and comprehensive information to researchers and academicians who are interested in radionuclide contamination, its sources and environmental impact. It is also useful for graduate and undergraduate students specializing in radioactive-waste disposal and its impact on natural as well as manmade environments. A number of sites are affected by large legacies of waste from the mining and processing of radioactive minerals. Over recent decades, several hundred radioactive isotopes (radioisotopes) of natural elements have been produced artificially, including 90Sr, 137Cs and 131I. Several other anthropogenic radioactive elements have also been produced in large quantities, for example technetium, neptunium, plutonium and americium, although plutonium does occur naturally in trace amounts in uranium ores. The deposition of radionuclides on vegetation and soil, as well as the uptake from polluted aquifers (root uptake or irrigation) are the initial point for their transfer into the terrestrial environment and into food chains. There are two principal deposition processes for the removal of pollutants from the atmosphere: dry deposition is the direct transfer through absorption of gases and particles by natural surfaces, such as vegetation, whereas showery or wet deposition is the transport of a substance from the atmosphere to the ground by snow, hail or rain. Once deposited on any vegetation, radionuclide s ar e removed from plants by the airstream and rain, either through percolation or by cuticular scratch. The increase in biomass during plant growth does not cause a loss of activity, but it does lead to a decrease in activity concentration due to effective dilution. There is also systemic transport (translocation) of radionuclides within the plant subsequent to foliar uptake, leading the transfer of chemical components to other parts of the plant that have not been contaminated directly.
Download or read book KLEBSIELLA written by and published by . This book was released on 1993 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Research Abstracts written by and published by . This book was released on 1994 with total page 806 pages. Available in PDF, EPUB and Kindle. Book excerpt: Semiannual, with semiannual and annual indexes. References to all scientific and technical literature coming from DOE, its laboratories, energy centers, and contractors. Includes all works deriving from DOE, other related government-sponsored information, and foreign nonnuclear information. Arranged under 39 categories, e.g., Biomedical sciences, basic studies; Biomedical sciences, applied studies; Health and safety; and Fusion energy. Entry gives bibliographical information and abstract. Corporate, author, subject, report number indexes.
Download or read book The Importance of Chemical Speciation in Environmental Processes written by M. Bernhard and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 758 pages. Available in PDF, EPUB and Kindle. Book excerpt: Report, the editors replaced the term "speciation" wherever it occurred by "identification and quantification," or "description of abundance," or "reactivity," or "transformation" of a chemical species, according to whichever one of the four meanings the author had evidently meant to convey. In line with the Dahlem Workshop Model, this Report comprises the background papers written in advance of the meeting on the current status of problems in environmental research and on advanced analytical tech niques for the identification and quantification of chemical species, as well as the group reports summarizing the results of the discussions held during the meeting. Each group report was prepared during the meeting by one "rapporteur" with the help of members of that group and finalized by the rapporteur (listed as the first author of the group report) after the meeting, taking into account both verbal comments made during the presentation of the reports in the plenary session at the end of the workshop and written comments received afterwards.
Download or read book Aspects of the Environmental Chemistry of Technetium written by James Allen Gawenis and published by . This book was released on 2001 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: Technetium-99 is a high yield daughter product from fission reactions. The chemistry of this isotope makes it an environmental contaminant that is difficult to remove. This dissertation describes three aspects regarding the chemistry of technetium and its chemical analog, rhenium. The second chapter discusses a new method of extracting anionic metals from water with supercritical fluid carbon dioxide. Efficient extraction of tetrabutylammonium perrhenate was performed with methanol modified supercritical fluid carbon dioxide. This extraction was performed without complexation of rhenium prior to extraction. The third chapter examines the use of host-guest chemistry to selectively remove pertechnetate from aqueous systems. A metallated cyclotriveratrylene-type host selectively removed pertechnetate from saline at high efficiency in the presence of similar anions. The fourth chapter describes the possible use of technetium, in various chemical complexes, as a tracer for hydrological flows. Technetium-99m pharmaceuticals were added to different soils and water types to determine their sorption characteristics. Pertechnetate was found to have the lowest sorption while the complexed pharmaceuticals showed mixed, but higher, sorption.
Download or read book Research Program to Investigate the Fundamental Chemistry of Technetium written by and published by . This book was released on 2004 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: Technetium (99Tc, half-life = 2.13 x 105 years,?-emitter) is one of the radionuclides of major concern for nuclear waste disposal. This concern is due to the long half-life of 99Tc, the ease with which pertechnetate, TcO4−, migrates in the geosphere, difficulties in incorporating technetium into glass waste forms, and the corresponding regulatory considerations. The problem of mobility of pertechnetate in the environment is compounded by the fact that pertechnetate is the thermodynamically stable form of technetium in oxidizing environments. These factors present challenges for the separation and immobilization of technetium. The objective of this research project is to provide new knowledge about the chemical behavior of technetium so that the factors underlying technetium speciation in nuclear waste and in waste forms can be understood and the problems can be addressed. In particular, the behavior of technetium and rhenium in glass will be examined since rhenium is ofte n used as a non-radioactive surrogate to predict the behavior of technetium. In this project, glasses containing both rhenium and technetium will be prepared, so that the behavior of both metals can be compared under identical conditions.
Download or read book Plants and the Chemical Elements written by Margaret E. Farago and published by John Wiley & Sons. This book was released on 2008-07-11 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt: How do plants react to elements in the soil? A vital question, particulary in today's world of increasing environmental contamination... The answer can be found in this book. It has an extraordinarily broad basis, compiling up-to-date information from numerous specialist disciplines. Key articles are devoted to - Soil Chemistry and Bioavailability - Metal-tolerant Plants - Metalloenzymes - Toxic Effects of Metals - Radionuclides Moreover emphasis is placed on environmental aspects, with detailed considerations of plants that hyperaccumulate heavy metals and plants that are indicators for pollution. A discussion of experimental techniques rounds off the book. They include sampling, sample preparation, analytical methods and aspects of quality assurance. All in all a valuable forum for the exchange of current thinking across a broad spectrum of disciplines.
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 Technetium written by Klaus Schwochau and published by John Wiley & Sons. This book was released on 2008-11-21 with total page 461 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dieses einzigartige Handbuch gibt eine umfassende Übersicht über den aktuellen Stand der Technetium-Chemie und die Anwendung von Technetium in der Radiopharmazie. Klar und präzise dargestellt werden alle wichtigen Aspekte wie · natürliches und künstlich verursachtes Vorkommen in der Umwelt, · Isotope und Isomere, · Analytische Chemie und Biochemie, · thermodynamische Daten, Stabilität und Reaktivität, · intermetallische und binäre Verbindungen, und vor allem · Komplexchemie sowie · radiopharmazeutischer Einsatz. Dieses herausragende Werk erlaubt sowohl Experten als auch Laien mit naturwissenschaftlicher Bildung einen schnellen Zugang zu wichtiger Information. Deshalb ist das Handbuch genauso unverzichtbar für Forscher an Universitäten und Instituten, in der Nuklearmedizin und radiopharmazeutischen Industrie wie für wissenschaftliche Berater in Regierungen und Umweltverbänden.
Download or read book Chemical Speciation of Organic and Inorganic components of Environmental and Biological Interest in Natural Fluids written by Francesco Crea and published by MDPI. This book was released on 2020-03-25 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: The International Union of Pure and Applied Chemistry (IUPAC) defines the term “speciation” as the distribution of an element amongst defined chemical species in a system, while the process leading to quantitative estimation of the content of different species is called speciation analysis. The chemical speciation of elements in natural waters and biological fluids is a key topic, essential for discussing the chemical reactivity of constituents in these systems. It is well understood that it is the chemical form of a metal or metalloids that determines its reactivity, lifetime, and fate in the environment. Chemical speciation now involves various sectors of the sciences, from chemistry to biology, biochemistry, and environmental sciences, since—as is well known—the total concentration, alone, of an inorganic or organic component (metal or ligand) in a multicomponent natural system (fresh water, sea water, biological fluids, soil, etc.) is insufficient for a comprehensive understand of its behavior in those contests.
