SORPTION-KINETIC CHARACTERISTICS OF THE TERMOKSID-3A SORBENT

We have studied kinetics of sorption of cesium and alkaline-earth radi onuclides from aqueous solutions on the Termoksid-3A sorbent and the m echanism of sorption processes. Sorption of barium, radium, and cesium radionuclides is likely to occur by the ion-exchange mechanism (n < 1 ), controlled by external diffusion for barium and radium and internal diffusion for cesium. The strontium sorption probably occurs by the c hemisorption mechanism (n > 1) controlled by external diffusion and ac companied by the formation of a layer (or a phase) of a chemical compo und of strontium with the sorbent on the sorbent surface. we have show n that good sorption kinetics on the Termoksid-3A sorbent ensure its e fficient application for removing long-lived fission radionuclides suc h as Sr-90 and Cs-137 from aqueous media.