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Mechanism of Ionic Diffusion in Dense Bentonite

Published online by Cambridge University Press:  26 February 2011

S.C.H. Cheung  and
M. N. Gray
S.C.H. Cheung
Affiliation:
Atomic Energy of Canada Limited, Pinawa, Manitoba ROE ILO, Canada
M. N. Gray
Affiliation:
Atomic Energy of Canada Limited, Pinawa, Manitoba ROE ILO, Canada
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Abstract

A new model based on ionic diffusion in surface (bound) and interstitial (free) water in compacted bentonite systems has been developed. The model is supported by data obtained from flow-through diffusion experiments using Cs+, I- and Cl-. The results show that diffusion depends on the charge of the diffusing species: cations are attracted to the clay particle surface, but are not immobilized, whereas anions are repelled from the clay particle surface. Cations diffuse through both surface and interstitial water, and anions diffuse mainly through interstitial water. The clay structure has been found to affect the diffusion of cations and anions.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 127: Symposium BERLIN – Scientific Basis for Nuclear Waste Management XII , 1988 , 677
Copyright
Copyright © Materials Research Society 1989

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References

REFERENCES

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