Separation of cesium and strontium from aqueous solutions by sorbents based on bentonite clays

Abstract

The possibility of using an intercalated montmorillonite for separation of cesium and strontium radionuclides from aqueous solutions was studied in this work. The distribution coefficients of Cs and Sr were Kd = (2.5 ± 0.2)×103 L/kg. The time of achieving sorption equilibrium did not exceed 10 minutes that indicates the external diffusion as the limiting stage of sorption. Adsorption of strontium occurs due to formation of a monolayer in pores of the sorbent and it can be described by Langmuir equilibrium. Separation of cesium occurs as a result of poly layer adsorption due to dehydration of cesium ions. Static exchange capacity of the sorbent was found to be 1.7 mmol/g and 1.6 mmol/g for cesium and strontium respectively. The experimental data can be used for development of technological schemes of rehabilitation of water sources at radioactively contaminated lands. © 2018 Author(s).