Sorption studies of cesium on TiO 2–SiO 2 mixed gel spheres

Abstract

TiO 2–SiO 2 mixed gel spheres used for the sorption studies of cesium were prepared via sol–gel method. The source solutions used for the process were prepared from different mixtures of 1 M TiCl 4 and 1 M Na 2SiO 3 solutions and converted into droplets in a gelation column. The suitable spheres for cesium adsorption were obtained using a methyl isobutyl ketone solution as the drop formation medium and ammonia as the gelling agent. The mixed oxide gels were identified and characterized by Analysis Adsorptive (N 2), DTA/TGA, FTIR and XRD analyses. The sorption behavior of Cs + cations on TiO 2–SiO 2 mixed gel spheres has been studied as a function of TiO 2 weight ratio, pH, time, cation concentration, temperature and competing ions. Sorption data have been interpreted in terms of Freundlich and Dubinin–Radushkevich equations. Sorption of Cs + cations were found to be endothermic in nature with Δ H° (kJ/mol) of 5.06, and Δ S° (kJ/(mol K)) of 0.06. Negative Δ G° value obtained for Cs + cations indicates the spontaneity of its sorption on mixed oxide gel spheres.