Reactivity of bentonite: an additive model applied to uranyl sorption

摘要: Compacted bentonite is a major packing and storage material, due to its extremely low hydraulic conductivity. Although the physical transport through bentonite is limited, it is also essential to understand the mechanisms of radionuclide sorption on important reactive mineral surfaces present in the bentonite. While the sorption properties and cation exchange capacity of bentonite have been studied experimentally, a descriptive model incorporating the possible fundamental sorption mechanisms is lacking. Since sorption of radionuclides onto mineral surfaces can be a major process reducing radionuclide migration as dissolved constituents from nuclear waste repositories to the environment, the attenuation capacity of packing and storage materials for radionuclides is a crucial characteristic controlling its suitability.In this chapter, an additive mixed-component model to describe the surface complexation of …