Study and characterization of zeolites for the removal of artificial radionuclides in wastewater samples from nuclear power plants

Abstract

4A, 13X, phillipsite and chabazite zeolites have been characterized regarding their capacity to remove Cs⁺ and Co²⁺ ions from aqueous solutions. The aim is to simulate the decontamination process of radioactive wastewater, originating from the former Garigliano nuclear plant in Italy, which is contaminated with ¹³⁷Cs and ⁶⁰Co. The four zeolites, in powder state, have been tested with solutions containing cesium nitrate and cobalt nitrate hexahydrate, in both individual and combined configurations, at different solid/liquid ratios. The Cs⁺ and Co²⁺ concentrations have been monitored over time by inductively coupled plasma (ICP) spectrometry. The results demonstrate the high efficacy of 13X zeolite providing almost 100 % of removal of both elements in a relatively short time (20–30 min). These findings are the basis for the kinetic characterization of the zeolite using radioactive solutions and, hence, for the setup of an in-situ pre-pilot plant to carry out tests with contaminated wastewater at the Garigliano facility. 13X zeolite presents a promising alternative for decommissioning radioactive wastewater.