Abstract In this study, at first was determined the structure of the natural clinoptilolite of the sabzevar region and investigate the adsorption properties of this absorbent towards Cs+ ion from aqueous solution. The effects of various parameters like pH, contact time, initial metal ion concentration and temperature were studied in batch operation. The results show that maximum adsorption capacity of cesium on to clinoptilolite adsorbent was found to be 172.4 mg.g-1. Then, the cesium-loaded adsorbents were heated at different temperature and the leach test carried out on all the heat-treated samples. Leaching results show that immobilization ability of ion cesium in the heated-treated materials increased as the treatment temperature was increased.
