Evaluation of Selective Sorbents for the Extraction of Valuable Metal Ions (Cs, Rb, Li, U) from Reverse Osmosis Rejected Brine

Three commercially available sorbents/exchangers (namely CsTreat, ZrP, and S910) were evaluated under column conditions for the extraction of four metals (Cs(I), Rb(I), Li(I), and U(VI)) from a brine rejected by a Seawater Reverse Osmosis plant. From the obtained breakthrough curves and periodic analysis of the influent and effluent, the uptake capacities of the materials were quantified. The fixation of the target metal onto the sorbents was investigated also by SEM-EDX and FTIR-ATR analysis. The results showed that CsTreat displayed a high sorption capacity of Rb(I) and a fairly high sorption capacity of Cs(I), as the resin S910 showed of U(VI), while ZrP proved to be ineffective for the retention of Li(I).