Read Books Online and Download eBooks, EPub, PDF, Mobi, Kindle, Text Full Free.
Download Environmental Behavior Of Technetium In Soil And Vegetation full books in PDF, epub, and Kindle. Read online Environmental Behavior Of Technetium In Soil And Vegetation ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Author : Frank Owen Hoffman
Publisher :
ISBN 13 :
Total Pages : 116 pages
Book Rating : 4.:/5 (359 download)
Download or read book Environmental Behavior of Technetium in Soil and Vegetation written by Frank Owen Hoffman and published by . This book was released on 1982 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Environmental Behavior of Technetium in Soil and Vegetation written by and published by . This book was released on 1982 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Significant radiological exposures have been estimated for hypothetical atmospheric releases of Tc-99 from gaseous diffusion facilities when vegetation-to-soil concentration ratios representative of laboratory experiments are substituted for generic default values assumed in current regulatory models. To test the relevancy of these laboratory ratios, field investigations were conducted to obtain measurements of the vegetation-to-soil concentration ratio for Tc-99 in samples collected near operating gaseous diffusion facilities and to observe the dynamic behavior of technetium in soil and vegetation following a single application of a sprayed solution of /sup 95m/TcO4− Comparison of observed field concentration ratios and calculated steady-state concentration ratios with ratios obtained from previous laboratory experiments indicates that concentration ratios obtained from field data are one to two orders of magnitude less than those obtained from the laboratory. Furthermore, a substantial accumulation of technetium in soil and vegetation may not occur over long periods of time, since concentrations of technetium in both environmental media were observed to decrease with time subsequent to initial application of /sup 95m/TcO4−.
Author : Edward Robert Landa
Publisher :
ISBN 13 :
Total Pages : 274 pages
Book Rating : 4.:/5 (319 download)
Download or read book The Behavior of Technetium-99 in Soils and Plants written by Edward Robert Landa and published by . This book was released on 1975 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : G. Desmet
Publisher : Springer Science & Business Media
ISBN 13 : 9400941897
Total Pages : 416 pages
Book Rating : 4.4/5 (9 download)
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 Technetium Behavior and Recovery in Soil written by and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author :
Publisher :
ISBN 13 :
Total Pages : 526 pages
Book Rating : 4.0/5 ( download)
Download or read book Energy Research Abstracts written by and published by . This book was released on 1994-04 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Lisa Hart Thorvig
Publisher :
ISBN 13 :
Total Pages : 224 pages
Book Rating : 4.:/5 (452 download)
Download or read book Factors Effecting Technetium-99 Behavior in Soils and Plants written by Lisa Hart Thorvig and published by . This book was released on 1978 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sampling of Technetium-99 in Vegetation and Soils in the Vicinity of Operating Gaseous Facilities. Environmental Sciences Division Publication written by and published by . This book was released on 1980 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Technetium-99 was measured in vegetation and soils collected near three operating gaseous diffusion facilities to obtain estimates of the soil-to-vegetation concentration factor. Analyses were performed primarily using radiochemical separations and low-level beta counting techniques with selected samples checked by isotope dilution mass spectroscopy. The concentration factor pooled from all three facilities appeared to be lognormally distributed with a geometric mean of 9.5 and a geometric standard deviation of 2.4. These values are comparable to calculated equilibrium concentration factors derived from other field experiments in which concentrations in soil and vegetation were observed to decrease with time subsequent to a single application of/sup 95m/TcO4−. These field values are one to two orders of magnitude less than concentration factors derived from laboratory experiments using potted plants. It is suggested that the radiologic significance of 99Tc in terrestrial food chains of importance to humans may be substantially lower than indicated by the simple difference between laboratory and field concentration factors if the time dependence of technetium activity in vegetation and soil is taken into consideration in radiological assessment models.
Download or read book Behavior of Technetium-99 in Soils and Plants written by and published by . This book was released on 1976 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Work described in this report is aimed at establishing the magnitude and mechanisms of $sup 99$Tc sorption by soils and uptake by plants. Studies showed that sorption of $sup 99$Tc by soils was essentially stopped by sterilization of the soil, further indicating that the sorption process is related to microbial activity. Studies also showed that sorption can occur under aerobic as well as anerobic conditions. However, there was considerable difference in the extent of sorption for different soils which remains to be explained. $sup 99$Tc was shown to be toxic to germinating seeds at low concentrations, but not when added to more mature plants. Initial evidence suggests this is a chemically rather than a radiologically induced toxicity but this remains to be completely resolved as well as whether there is a threshold level of $sup 99$Tc required before toxicity occurs. (auth).
Author :
Publisher :
ISBN 13 :
Total Pages : 68 pages
Book Rating : 4.:/5 (359 download)
Download or read book Sampling of Technetium-99 in Vegetation and Soils in the Vicinity of Operating Gaseous Diffusion Facilities written by and published by . This book was released on 1980 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Accumulation of Technetium from Soil by Plants written by and published by . This book was released on 1975 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The isotope $sup 99$Tc (T $sup 1$/$sub 2$, 2.15 x 10$sup 5$ years) is produced by the spontaneous fission of $sup 238$U in nature and by the slow neutron fission of $sup 238$U in nuclear reactors. In the latter case, the potential exists for Tc entrance into the environment in emissions from nuclear reactors, nuclear fuel reprocessing plants, and other facilities which use Tc for commercial purposes. Results are reported from studies on Tc uptake by plants. The most stable chemical species of Tc in aqueous solution is the pertechnetate ion (TcO$sub 4$$sup -1$), and it is this form which is most likely to enter surface soils. Recent studies indicated that at least over the short term, pertechnetate is soluble and highly mobile in most soils and is sorbed in significant quantities only in high organic matter, low pH soils. Plant availability normally increases with increased ion solubility in soil provided the ion is not discriminated against at the plant root level. Furthermore, the aqueous chemistry of pertechnetate is similar in several respects to permanganate and molybdate, compounds of elements essential in plant nutrition. Experiments were undertaken to determine the uptake and distribution of Tc in plants as a function of time using soybeans (Glycine max) and $sup 99$Tc as a tracer. (CH).
Author : Clemens Walther
Publisher : Springer
ISBN 13 : 331922171X
Total Pages : 277 pages
Book Rating : 4.3/5 (192 download)
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.
Author : Howard S Wheater
Publisher : World Scientific
ISBN 13 : 1908979402
Total Pages : 419 pages
Book Rating : 4.9/5 (89 download)
Download or read book Biosphere Implications Of Deep Disposal Of Nuclear Waste: The Upwards Migration Of Radionuclides In Vegetated Soils written by Howard S Wheater and published by World Scientific. This book was released on 2007-07-26 with total page 419 pages. Available in PDF, EPUB and Kindle. Book excerpt: The safety assessment of a deep repository for nuclear waste poses challenging scientific and technical questions. The risks from leakage of radionuclides from the repository, including transfers to the biosphere and the food chain must be assessed. This involves complex and poorly understood interactions between groundwater, soils, plants and the atmosphere. A unique, multidisciplinary experimental and modeling program at Imperial College London has been funded by UK NIREX to develop the science and to produce modeling tools to interpret and generalize the experimental data for safety assessment. This monograph brings together for the first time the accumulated results and experience from almost two decades of research. The results have important implications for the safety assessment of nuclear waste worldwide and provide new insights into the geochemical and biological controls on the upwards migration of radiochemicals in the near-surface environment./a
Download or read book Behavior of Technetium-99 in Soils and Plants. Final Report, April 1, 1974--December 31, 1978 written by and published by . This book was released on 1979 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Studies described in this report were aimed at establishing the magnitude and mechanisms of /sup 99/Tc sorption by soils and uptake by plants. Results show that /sup 99/Tc was sorbed from solution over a period to two to five weeks by 8 of 11 soils studies. The slow rate of sorption, the lack of sorption by low organic matter soils, the elimination of sorption following sterilization and increased sorption following addition of dextrose all point to a microbial role in the sorption process. However, it has not been established whether this is a direct or indirect role nor is it possible to clearly predict the conditions under which sorption will occur. Results of plant uptake studies show that /sup 99/Tc can be taken up and translocated into the photosynthetic tissue of higher plants with concentrations in seeds being much less than in vegetative tissue. Technetium-99 was also shown to be toxic to plants at low concentrations and evidence suggests that this is a chemically rather than radiologically induced toxicity. However, this remains to be completely resolved as well as whether there is a threshold level of /sup 99/Tc required before toxicity occurs. Studies of short-term, dynamic, aerobic systems indicated that /sup 99/Tc moves through the soil as a relatively large anion exhibiting characteristic miscible displacement with some asymmetric tailing. /sup 99/Tc exhibits greater retention that C1/sup -/, which may be attributed statistically to weak complexion by organic matter. It is unlikely that this retention phenomenon is related to the static sorption activity reported in the first part of this study.
Author :
Publisher :
ISBN 13 :
Total Pages : 612 pages
Book Rating : 4.E/5 ( download)
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1976 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Behavior of Technetium-99 in Soils and Plants. Progress Report, April 1, 1974--March 31, 1975 written by and published by . This book was released on 1975 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author :
Publisher : Elsevier
ISBN 13 : 0080474896
Total Pages : 307 pages
Book Rating : 4.0/5 (84 download)
Download or read book Radioactivity in the Terrestrial Environment written by and published by Elsevier. This book was released on 2007-03-02 with total page 307 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Radioactivity in the Environment Series addresses the key aspects of this socially important and complex interdisciplinary subject. Presented objectively and with the ultimate authority gained from the many contributions by the world's leading experts, the negative and positive consequences of having a radioactive world around us is documented and given perspective. In a world in which nuclear science is not only less popular than in the past, but also less extensively taught in universities and colleges, this book series will fill a significant educational gap. Radioactivity in the Terrestrial Environment presents an updated and critical review of designing, siting, constructing and demonstrating the safety and environmental impact of deep repositories for radioactive wastes. It is structured to provide a broad perspective of this multi-faceted, multi-disciplinary topic providing enough detail for a non-specialist to understand the fundamental principles involved. Contains extensive references to sources of more detailed information Provides a detailed summary of radioactivity in terrestrial ecosystems, providing a substantial and essential reference on the subject Discusses lesser-known sources of radiation exposure that provide useful information for those seeking to place environmental radioactivity into perspective
