RSM-based Investigation of Cesium Removal from Aqueous Media with Nanocomposites Prepared by Spherical Mesoporous Silica and Potassium Metal Hexacyanoferrate

Abstract

We investigated the effects of different variables on cesium adsorption from aqueous solutions using a synthesized nanocomposite. The surfaces of synthesized spherical mesoporous silica were modified with potassium hexacyanoferrate and characterized by different techniques including XRD, FT-IR, SEM, TGA, and BET/BJH. The response surface methodology based on the central composite design was used to optimize cesium ion adsorption conditions such as the effects of initial cesium concentration, contact time, temperature, and pH. The equilibrium concentration data were analyzed by Langmuir, Freundlich, and Tempkin isotherm models. The isotherm studies showed that monolayer adsorption isotherm (Langmuir) is consistent with the experimental data. Based on kinetic studies, Blanchard's pseudo-second-order reaction kinetics model provides the best correlation of the experimental data. The initial concentration and pH were the most influential factors in cesium adsorption. The result showed the nanocomposite adsorbed cesium ions selectively even in the presence of high Na + , K + , and Sr 2+ ions.