ADSORPTION BEHAVIOR OF CESIUM AND STRONTIUM ON SYNTHETIC ZEOLITE-P

Adsorption behavior of Cs and Sr on a synthetic zeolite P has been studied. Natural zeolites, clinoptilolite and mordenite, were converted into the zeolite P having a high crystallinity through hydrothermal treatment with NaOH solutions. The distribution coefficient (K(d)) for Cs+ and Sr2+ depended on pH in acidic region, while attained nearly constant values around 10(3) cm3/g in neutral and alkaline regions. This value is almost the same as that for Cs+ and about ten times that for Sr2+ on the original clinoptilolite. The adsorption obeys Langmuir-type isotherms, and the saturated amounts of Cs and Sr were respectively estimated to be 1.76 and 1.84 mmol/g. The zeolite P containing these cations was readily converted into a stable solid form consisting of pollucite and Sr-feldspar by calcination above 1,000-degrees-C.