Anion exclusion and sorption effect for compacted bentonite: the dependency of diffusion coefficients and capacity of HTO and Se(IV)

Quantitative calculation based on the joint action of anion exclusion and sorption has not been reported. This article studies the diffusion behavior of Se(IV) in MX-80 bentonite fills in different lengths by the through-diffusion method. The anion exclusion and sorption are simultaneously considered and quantitatively calculated. The results show that the effective diffusion coefficient of Se(IV) decreases with the increasing lengths of bentonite plug, because of the joint action of anion exclusion and sorption. On this basis, the anion exclusion and sorption are first quantitatively calculated, then a new theory for calculation is proposed in this article. The calculation results show that the ratio of anion exclusion and sorption. In groundwaterenvironments and seawaterenvironments, the weight of sorption is lower than anion exclusion in diffusion process.