Sorption and desorption behavior of cesium on soil components

The sorption desorption behaviors of Cs ion in the concentration region of 10 −9 to 10 −4 m-equiv mL −1 were studied using bentonite, humic acid and sand as well as their mixtures. The Cs cation was indicated from the results of desorption studies to have, to a large extent, been sorbed to the interlayer sites of bentonite in an irreversible manner, while the sorption of Cs on humic acid and sand was reversible. In the experiments with mixed sorbents K d value decreased with increasing quantities of humic acid in the region where humic was below 6%; in addition, some sorption sites of bentonite were confirmed to have been blocked by humic acid. Humic acid, in the region where it is over 6%, would become the primary sorbent for Cs instead of bentonite, which would be blocked with humic acid.