Temperature and pH effects on sorption properties of subseabed clay

The effect of time (1 to 14 days), temperature 20 to 600C) and pH (2 to 10) on sorption of Cs, Sr, Eu, and Ba onto subseabed smectite clay was studied through batch equilibrium techniques. Sorption equilibrium was reached by all elements within four days. All except Cs exhibited a pH dependence. The equilibrium sorption distribution coefficient (K/sub d/) for Cs was inversely dependent on temperature (Cs, 1180/20 C, 340/160 C), whereas the others showed little or no dependence (Sr, 130/20 C, 170/60 C), (Eu, 1.0 x 107/20 C, 1.1 x 107/60 C) and (Ba, 7.0 x 104/20 C, 7.0 x 104/60 C). This would indicate that for the conditions used, the subseabed smectite can be considered as a viable geological release barrier