Kinetic and thermodynamic studies for cesium removal from low-level liquid radioactive waste using impregnated polymeric material

A novel polymeric impregnated material was prepared by loading 4,4′(5′)di-t-butylbenzo-18-crown-6 (DtBB18C6) onto poly(acrylamide-acrylic acid-acrylonitrile)-N,N′-methylenediacrylamide [P(AM-AA-AN)-DAM]. The sorption of 137Cs onto P(AM-AA-AN)-DAM/DtBB18C6 was studied using batch equilibrium technique with respect to the pH, contact time, and temperature. The applicability to treatment of low-level liquid radioactive waste was examined. The free energy (ΔG0), enthalpy (ΔH0), and entropy (ΔS0) of the sorption were calculated. These parameters showed that the sorption of 137Cs onto P(AM-AA-AN)-DAM/DtBB18C6 was spontaneous and endothermic in nature. The Lagergren first-order, pseudo-second-order, and homogeneous particle diffusion models were tested kinetically to describe the reaction mechanism. The experimental data were fitted well by the pseudo-second-order kinetic model.