Radiochemische Bestimmung des Kationenaustauschvermögens von Tonmineralen

Boehm, H. P.; Lieser, Κ. H.

doi:10.1002/zaac.19603040312

Cited by 8 publications

(3 citation statements)

References 13 publications

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“…Assuming a particle size of 10/im and an effective diffusion coefficient of the order of 10" 10 cm 2 s -1 , the halftime of the exchange reaction within the particles is of the order of one hour. Half-times of this order of magnitude have been observed with clay minerals [17]. All experiments were carried out for periods of time of 30 to 90 days to ensure equilibration.…”

Section: Ion Exchange Of Cs On Inorganic Solidsmentioning

confidence: 99%

Chemistry of Radioactive Cesium in the Hydrosphere and in the Geosphere

Lieser

Steinkopff

1989

Radiochimica Acta

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Cesium /Sorption of Cesium/Colloids/Clay minerals /Ion exchange SummaryCesium is sorbed with relatively high selectivity by clay minerals. Accordingly, in groundwaters Cs is found in high amounts in suspended matter or in colloids, if these consist of or contain clay minerals. The sorption of Cs in sediments is also mainly determined by the presence of clay minerals and the sorption ratio at low salinity is found to be roughly proportional to the clay content in the sediments. Furthermore, with the same sediment the sorption ratio is inversily proportional to the concentration of NaCl which proves that ion exchange on the clay minerals is the prevailing sorption mechanism for Cs.It is shown that the sediments contain small amounts of sorption sites of high selectivity for Cs + which govern the sorption behaviour at very small concentrations of Cs + ions. These sorption sites are also responsible for Cs + sorption on suspended particulates of clay in the groundwaters.

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Section: Ion Exchange Of Cs On Inorganic Solidsmentioning

confidence: 99%

Chemistry of Radioactive Cesium in the Hydrosphere and in the Geosphere

Lieser

Steinkopff

1989

Radiochimica Acta

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“…The exchange properties of clay minerals have been investigated in great detail [137,195,[241][242][243][244][245][246][247][248][249]. On the one hand, sorption and exchange sites, respectively, are available at the outer surfaces, similar to those present at the surface of alumosilicates (^SiOH and ^AlOH groups).…”

Section: Unconsolidated Rocksmentioning

confidence: 99%

Radionuclides in the Geosphere: Sources, Mobility, Reactions in Natural Waters and Interactions with Solids

Lieser

1995

Radiochimca Acta

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The various sources of radioactivity are considered. Natural and anthropogenic radionuclides are selected with regard to their importance in the geosphere and listed according to their chemical properties. The importance of the solubility of the radionuclides is emphasized and in view of their mobility five compartments are distinguished: surface of the earth, atmosphere, near-surface layers (with connection to the surface), nuclear installations and deep layers without connection to the surface.In a following chapter, the reactions of radionuclides with the components of natural waters are discussed. The importance of the knowledge of the chemical forms (speciation) is stressed and illustrated by examples. The influences of Eh and pH, inorganic salts, colloids, suspended matter, organic compounds and microorganisms as well as that of precipitation and coprecipitation is brought out. Then, the interaction of radionuclides with solid components of the geosphere are dealt with. After description of general aspects, interactions with consolidated rocks, unconsolidated rocks, various minerals, sediments and soils are discussed. Isotopic and non-isotopic exhange reactions of radionuclides on minerals are also considered. Finally, the problems of modelling are discussed.

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Section: Unconsolidated Rocksmentioning

confidence: 99%

Radioactivity: A Tool to Explore the Past

Gunten

1995

Radiochimca Acta

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The use of the radioactive decay for dating purposes is reviewed. The most important dating methods are discussed. They include radioactive time markers (e.g., 137 Cs), cosmogenic radionuclides (e.g., ,4 C, "'Be), decay products of 226 Ra (e.g., 222 Rn, 210 Pb), uranium-thorium-lead chronometers, rubidium-strontium and potassium-argon nuclide pairs, applications of radioactive disequilibrium, dating with fission tracks, and thermoluminescence. Some important results, for instance the age of the Earth and the Moon, are also presented.

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Radiochemische Bestimmung des Kationenaustauschvermögens von Tonmineralen

Cited by 8 publications

References 13 publications

Chemistry of Radioactive Cesium in the Hydrosphere and in the Geosphere

Chemistry of Radioactive Cesium in the Hydrosphere and in the Geosphere

Radionuclides in the Geosphere: Sources, Mobility, Reactions in Natural Waters and Interactions with Solids

Radioactivity: A Tool to Explore the Past

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