Sorption kinetics of cesium on ZrO2 and ZrO2-SiO2-TiO2 microspheres

Abstract

ZrO2 and ZrO2-SiO2-TiO2 (with 1:1:1 mol ratio) microspheres have been prepared by the sol-gel method and characterized to study the sorption kinetics of cesium. The effect of pH on the adsorption capacity was determined for both type sorbents and the maximum adsorption percentage of cesium was observed at pH 10. To elucidate the kinetics of the ion-exchange reaction on pure and ternary oxide microspheres, the isotopic exchange rates of cesium ions between both types of sorbent microspheres and aqueous solution were measured radiochemically and compared with each other. The diffusion coefficients of Cs+ ion for ZrO2 and ZrO2-SiO2-TiO2 sorbent microspheres at pH 10 were calculated as 3.648×10−8 m2 s−1 and 6.383×10−8 m2 s−1, respectively, under particle diffusion controlled conditions.