Cation exchange equilibria in binary systems of Cs/sup +/, Sr/sup 2+/, or Ce/sup 3+/ with other cations expected in fission product recovery solutions are presented for several zeolites (Linde 4AXW, 13X, AW-400, AW-500, Norton Zeolon, and clinoptilolite) along with a method of estimating zeolite loadings for multication systems. Strontium breakthrough curves are calculated from equllibrium and diffusion data for comparison with experimental breakthrough curves. Cesium and strontium loadings of about 1.5 and 2.5 meq/g of zeolite, respectively, were obtained with cesium and strontium feed solutions. Column results show 0.9 and 1.3 meq/g of cesium and strontium, respectively, loaded together on 4A from a simulated CSREX IBP solution. (auth)