Cesium Ion Decontamination by Layered Perovskite HCa2Nb3O10·1.5H2O

Abstract The ion-exchange properties of the layered perovskite HCa2Nb3O10·1.5H2O toward cesium ion were examined. The Cs+ uptake by the protonated material follows the Langmuir model with uptake capacity of 0.82 mmol g−1 at equilibrium pH 3.3. The Cs+ uptake capacity decreased with increase in equilibrium pH showing 1.0 mmol g−1 at pH 1.6 and 0.70 mmol g−1 at pH 10.2. The selectivity order determined by comparison of the distribution coefficient (Kd) values was Cs+ > Na+ > K+ >> Ca2+ > Mg2+ at equilibrium pH 3.4 or 2.5 from initial concentration of 0.10 or 1.0 mmol dm−3 solution containing cations, respectively. The protonated material was efficient for Cs+ decontamination (ca. 100%) from drinking water spiked with 0.01 or 0.10 mmol dm−3 CsCl at volume to mass ratio (V/m) of 0.1–1.0 dm3 g−1. The protonated material can be regenerated after treatment of Cs+-exchanged material with 5 mol dm−3 HNO3 solution.