Bentonite phosphate modified with nickel: Preparation, characterization, and application in the removal of 137Cs and 152+154Eu

Abstract

The present study concerns the sorption of 137Cs and 152+154Eu from low-level radioactive waste (LLW) by bentonite phosphate modified with nickel (BPN) sorbent material. BPN was synthesized using the precipitation method and characterized using various analytical techniques such as Fourier transform infrared (FT-IR), scanning electron microscope (SEM), X-ray fluorescence (XRF), and X-ray diffraction (XRD). The sorption data show that 90 min is enough time to reach equilibrium. The distribution coefficients of 137Cs and 152+154Eu were studied as a function of pH. The distribution coefficient Kd was 2122.2 mL g−1 and 1076.5 mL g−1 for 137Cs and 152+154Eu at pH 9 and 4. The adsorption capacity of BPN has values of 31.1 and 28.2 mg g−1 for 137Cs and 152+154Eu, respectively. The effect of interfering species shows that the rate of adsorption of 137Cs and 152+154Eu slightly decreases as the concentration of the interfering species increases. The investigation of BPN for removing 137Cs and 152+154Eu radionuclides was conducted using a real LLW sample. Results showed that the BPN is appropriate to remove 137Cs and 152+154Eu from liquid radioactive waste and can be considered a potential composite for the purification of effluent polluted with these radionuclides.