Removal of 134 Cs and 152+154 Eu from liquid radioactive waste using Dowex HCR-S/S

Radionuclides should be separated from the waste streams before their discharge due to their undesired effects on human physiology and ecological systems. In this work, the feasibility of using Dowex-HCR-S/S(HCR), a strong acid cation-exchange resin as sorbent for 134 Cs and 152+154 Eu ions removal was examined. Sorption experimental data were analyzed by kinetic and isotherm models. The distribution coefficients of 134 Cs and 152+154 Eu were studied as a function of pH; 3525.6 mL/g and 393.1 mL/g were obtained in case of 152+154 Eu and 134 Cs at pH 4.1, respectively. Four isotherm models; Freundlich, Langmuir, Tempkin and Dubinin-Radushkevich, were used to fit the sorption equilibrium data. The results indicated that the sorption of both 134 Cs and 152+154 Eu onto HCR resin is highly fit with the pseudo-second order model. The sorption kinetic for 134 Cs and 152+154 Eu onto polymeric resin takes 90 and 120 min to reach equilibrium which is considered as a fast kinetic process. The results of sorption experiments indicate that the maximum sorption capacity of 134 Cs and 152+154 Eu are 102.84 and 161.93 mg/g. The amount of radionuclides removed increased with increasing temperature, which indicates the endothermic nature of the sorption process. The negative values of ΔG ○ indicated the spontaneity of the sorption process. The proposed procedure has been successfully applied for the removal of 134 Cs, 152+154 Eu and other radionuclides from real liquid radioactive waste. The present study concludes that the commercial HCR resin used under these conditions, has a considerable potential as an effective sorbent for the removal of 134 Cs and 152+154 Eu from real radioactive wastewater. It can therefore have a place in the treatment of cationic radionuclides from radioactive wastewater since it is of a low-cost and commercially available adsorbent.