Modification of the structure of natural bentonite and study on the sorption of Cs+

Natural bentonite clay was treated in order to remove impurities to increas e the cation exchange capacity of the montmorillonite and to obtain a more effective radioactive cesium sorption. It was found that the treatment of t he clay determines the amount of sorbed cesium. On the other hand it was sh own that montmorillonites may retain cesium through several mechanisms whic h provide strongly retained cations occupying cationic sites into the clay structure or sorbed cesium which may be lost by purification treatments.