Kinetic and isothermal adsorption properties of strontium and cesium ions by zeolitic materials synthesized from Jeju volcanic rocks

Abstract

The study focused on the removal of Sr and Cs ions in aqueous solutions by zeolitic materials synthesized from Jeju volcanic rocks using a fusion/hydrothermal method. The synthesis of the zeolitic materials was carried out using the fusion/hydrothermal method to reduce crystallization time. Morphological structures of the zeolitic materials could be confirmed to be the Na-A zeolite structure and crystalline with the chamfered-edged structure. In the adsorption experiment, as the initial concentrations of the Sr and Cs ions increased, it took longer to reach adsorption equilibrium. The adsorption kinetics and isotherms of Sr and Cs ions were predicted well by the pseudo-2nd-order and Langmuir isotherm models, respectively. The maximum adsorption capacities of Sr and Cs ions by the Langmuir isotherm model were 154.8 mg/g and 144.0 mg/g, respectively. The zeolitic materials prepared in this study is considered as an effective adsorbent for removing Sr and Cs ions in aqueous solutions.