The Ion-exchange Equilibrium between Cesium and Phenol-sulfonic-acid-type Cation Exchange Resin

Abstract 1) In the Cs+–(NH4++NH3) exchange system, the distribution coefficients of cesium can be approximately expressed as follows: logKd=pH−1.6log[NH4++NH3]−8.8 2) In the Cs+–Na+ and Cs+–K+ exchange systems, the distribution coefficients of cesium can be expressed with a good approximation by: logKd=0.25log[OH−]−0.90log[Na+]+2.4 and logKd=0.25log[OH−]−0.90log[K+]+1.7 In the Cs+–NH4+ exchange system, the distribution coefficients of cesium can be expressed by: logKd=−1.1log[NH4+]+0.62 3) The specific adsorption of cesium by the active phenolic groups is observed when the pH value of the outer solution is above 12, and high selectivity is obtained above 13 for the Cs+–Na+ exchange system. For the Cs+–(NH4++NH3) exchange system, the specific adsorption of cesium is observed above pH 11, and an extremely high selectivity can be obtained when the total concentration of the outer solution is below 1 mol./l.