Study of sorption and diffusion processes in natural bentonites

Distribution coefficients (Kd) have been determined for Cs-134 and Sr-85 by the batch method. Various factors affecting the K-d value as water-to-bent onite ratio and composition of the aqueous phase have been evaluated and wi ll be discussed. Effective (D-e) and apparent (D-a) diffusion coefficients for Sr-85 in the compacted bentonite have been determined using the through -diffusion method. Dry bulk density and porosity of the dry bentonite and t he water content in the saturated bentonite have been measured as well. Dis tribution coefficients calculated from the diffusion data using the dry bul k density and porosity values for given conditions have been compared and d iscussed with those determined by the batch method.