Sorption and diffusion of 90Sr2+ in compacted bentonite investigated by a capillary method

The effects of bentonite density and fulvic acid on the sorption and diffusion of 90Sr2+ in compacted bentonite were investigated by using a capillary method. The experiments were carried out at pH 7.0 ± 0.1 in the presence of 0.01M NaClO4. The results suggest that the sorption and diffusion of 90Sr2+ in compacted bentonite decreases with increasing the density of compacted bentonite. The presence of FA enhances the sorption of Sr2+, but reduces the diffusion of Sr2+ in compacted bentonite. The porosity of the compacted bentonite plays an important role in the sorption and diffusion behavior of 90Sr2+. Using the calculated effective diffusion coefficients the long-term relative concentration distribution of strontium was evaluated in compacted bentonite. (author)