Cs and Sr removal over highly effective adsorbents ETS-1 and ETS-2

Abstract

Engelhard titanosilicate-1 (ETS-1) and Engelhard titanosilicate-2 (ETS-2) were prepared. It was the first time their properties were studied for applications in water treatment. The performance of ETS-1 and ETS-2 in Cs and Sr removal was investigated and compared with those of ETS-4, Na-Y and Na-ZSM-5. Characterization revealed successful synthesis of ETS-1 and ETS-2, having layered structures with specific surface areas of about 120 m² g⁻¹ and 220 m² g⁻¹, respectively. The compositions of ETS-1 and ETS-2 were analyzed by XRF and TGA, and the theoretical exchange capacities for monovalent cations were calculated to be 6.70 mmol g⁻¹ and 8.12 mmol g⁻¹, respectively, assuming all the alkali metal cations could be exchanged. ETS-1 showed the highest Cs removal performance among the adsorbents studied, whereas ETS-2 was promising in Sr removal. In competitive removal experiments for Cs and Sr, the highest amount of Cs uptake was observed over ETS-1, though ETS-1 did not show specific selectivity to Cs removal.