Sorption of Cs+ and Sr2+ Cations by Titanium(IV) Phosphates from Solutions Modeling the Nuclear Power Plant Bottom Residue

Using a model solution, we have demonstrated the feasibility of using titanium(IV) oxyhydroxyphosphate-based ion-exchange materials for extraction of Cs+ and Sr2+ cations from multicomponent high-salt bottom residues. Conditions for the use of the ion exchangers have been optimized experimentally: liquid : solid = 50, t = 25°C. It has been shown that Cs+ is effectively extracted at pH 2, whereas Sr2+, at pH 8. The zirconium-modified sorbent has been shown to have a higher affinity for metal cations. The modified sorbent is especially selective for cesium in the acid pH region owing to the higher mobility of the protons of its hydrogen phosphate groups in comparison with the unmodified sorbent composition.