Sorption of 90Sr onto Manganese Oxides Prepared in Aqueous-Ethanol Media

Sorbents based on manganese oxides were prepared by KMnO4 reduction in aqueous-ethanol medium. The influence of the synthesis conditions (temperature and time of the sol-gel synthesis, type of structure-forming cations, calcination temperature) on the pore structure and on the performance and selectivity in 90Sr sorption was studied. The sorbents have the mesoporous structure with the specific surface area of 180–220 m2 g−1 and mean pore size of 10–20 nm. Manganese oxide of channel structure in the Na+ form, prepared by the reaction at 25°C for 5 h and heat-treated at 350°C, exhibits the highest performance and selectivity in 90Sr sorption (distribution coefficient Kd = 1.04 × 104 cm3 g−1, Sr-Ca separation factor DSr/Ca = 99). The sorbents synthesized exhibit the highest performance and selectivity in neutral and alkaline media.