Synthesis and evaluation of resorcinol-based ion-exchange resins for the selective removal of cesium

Control of the reaction conditions during the alkaline polycondensation of resorcinol with formaldehyde leads to polymeric resins with improved capaci ty toward caesium. The resins obtained are characterized by determining the ir moisture regain and ion-exchange capacity. The distribution coefficient (D) for alkali-metal cations are determined in a competitive extraction sys tem at different pH. The alkali-metal cation sorption selectivity series is strongly influenced by the pH of the solution. Two kinds of mechanism can explain these selectivity series. Extraction of caesium from simulated radi oactive waste was studied at different pH in the presence of a large excess of sodium. The study also includes the kinetic and the ion-exchange capaci ty for caesium of the sodium form of the resins.