Through-diffusion study of Se(IV) in gamma-irradiated bentonite and bentonite-magnetite

摘要

Through-diffusion experiments with HSeO3- and SeO32- (as a surrogate of Se-79(IV)) in bentonite samples have been performed. The effect of density, magnetite and irradiation on the experimental results have been investigated. It could be shown that the effect diffusion coefficient decreased with the increasing density. In the gamma-radiation bentonite and bentonite-magnetite, the diffusion coefficient for SeO32- and HSeO3- were (0.45-4.11) x 10(-11) m(2)/s and (0.95-3.74) x 10(-11) m(2)/s, respectively. While the K-d values were (1.19-4.00) x 10(-4) m(3)/kg and (1.83-4.86) x 10(-4) m(3)/kg, respectively. Moreover, the relationship of D-e and epsilon(acc) could be described by Archie's law. This study reveals that the magnetite has large influence on the diffusion, while the effect of gamma radiation on the bentonite is similar.