Format:
v, 32 Seiten
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Illustrationen
Series Statement:
Research report / Cold Regions Research and Engineering Laboratory, CRREL, US Army Material Command 320
Content:
CONTENTS: Preface. - Summary. - lntroduction. - 1. Sources and effects of cadmium in the environment: a brief review. - Sources of cadmium. - Health aspects of cadmium pollution. - Air pollution by cadmium. - Water pollution by cadmium. - Cadmium in soils. - Effect of cadmium on sewage treatment processes. - 2. The interaction of cadmium with some native New Hampshire soils. - Introduction. - Materials and methods. - Results and discussion. - Reversibility. - Conclusions. - Suggestions for further research. - 3. The flow of cadmium through soils: an experimental method. - Introduction. - Design criteria and detector performance. - Mathematical analysis of curves. - Conclusions. - Literature cited. - Abstract.
Content:
A brief review of the literature on cadmium in the environment, with emphasis on its role in soils and water, is presented. Experimentally, the interaction of cadmium with two soils and one naturally occurring zeolite was examined using calcium-saturated and potassium-saturated samples. The soils preferentially bound cadmium in the presence of either calcium or potassium with decreasing cadmium selectivity as the fractional cadmium surface coverage increased. Cadmium sorption was relatively higher with the potassium soils as compared with the calcium soils. For the loamy fine sand this increase was accounted for by electroselectivity principles, while such reasoning was inadequate to explain the increases observed with the Charleton loam sample. The preference for cadmium over calcium, as measured by the selectivity coefficient, was higher for the sandy soil. The zeolite was found to be calcium-selective. A method for monitoring the flow of cadmium through soil columns was examined. The use of spatial filtering, involving Fourier transforms, was found to be a suitable technique for monitoring the changes in cadmium concentration as it flows through soils. The experimental technique involves the use of gamma-emitting metal isotopes in conjunction with an external scintillation counter; thus the soil column remains undisturbed and may be used for several experiments.
Note:
MAB0014.001: ZSP-202-320
,
Online frei verfügbar
In:
Research report
Keywords:
Forschungsbericht
URL:
http://www.worldcat.org/oclc/1016535
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