[2C01-04] Material 1

[2C02] Effects of exchangeable cations on diffusion behavior of sulfate ions in montmorillonite

*Sato Hiroto¹, Shinichiro Uematsu¹, Naoko Watanabe¹, Tamotsu Kozaki¹ (1. Hokkaido Univ.)

Keywords:geological disposal, montmorillonite, diffusion mechanisms, activation energy, exchangeable cation, sulfate ion

Non-steady-state diffusion experiments were performed with sulfate ions using compacted homoionic Ca-montmorillonite samples with two different levels of dry densities.The apparent diffusion coefficients of sulfate ions were measured by this experiment, and the activation energies for diffusion were determined to discuss diffusion processes for sulfate ions in montmorillonite.The activation energies for diffusion measured in this study were compared with those for sulfate ions in compacted Na-montmorillonite obtained from previous studies.