Diffusion of some chemical species through a granite considering their geochemical properties

Through-diffusion experiments for some chemical species onto granite have been carried out to understand their diffusion characteristics according to their geochemical properties. The chemical species used in the experiment were classified into three groups as a nonsorbing tracer, simple cation and multivalent species. The difference in the diffusion process among the nonsorbing tracers was evaluated and discussed in terms of their interactions with the rock’s pore surface. The extent of surface diffusion was examined from the view of sorption reversibility for the sorbing cations. For the multivalent species, two kinds of experiments were performed to study the effects of geochemical conditions in acidic and alkaline solutions. Chemical species and sorption properties were also investigated as a function of the pH and carbonates in order to examine the effects of the carbonates on diffusion in alkaline conditions.