MULTICOMPONENT ION-EXCHANGE EQUILIBRIA IN CHABAZITE ZEOLITE

Efficient design of ion-exchange columns, using Ionsiv IE-96 chabazite zeolite, for the decontamination of process wastewater that contains ppb levels of Sr-90 and Cs-137 requires a detailed study of binary and multicomponent ion-exchange equilibria. Experimental isotherms were acquired for Ca-Na, Mg-Na, Sr-Na, Cs-Na, Sr-Cs-Na, Ca-Mg-Ng, Sr-Ca-Mg-Na, Cs-Ca-Mg-Na, and Sr-Cs-Ca-Mg-Na comparing batch and column experimental approaches. Binary isotherms obtained by the batch technique were most successfully fitted with a modification of the Dubinin-Polyani equilibrium model. Prediction of the multicomponent equilibria from binary data will require more sophisticated modeling.