Elaboration and characterization of molybdenum titanium tungsto-phosphate towards the decontamination of radioactive liquid waste from 137 Cs and 85Sr

Abstract

The crystalline phase of molybdenum titanium tungsto-phosphate (MoTiWPO4) as an inorganic sorbent material was synthesized via the sol–gel method. The physicochemical characteristics of MoTiWPO4 were evaluated by using Fourier transform infrared (FT-IR), scanning electron microscope (SEM), energy dispersive X-ray (EDX), thermal analysis (TGA-DTA), and X-ray diffraction (XRD). MoTiWPO4 sorbent material exhibits a high chemical resistance to HNO3, HCl, and alkaline media. MoTiWPO4 has good thermal stability as it retained about 75.63% of its saturation capacity upon heating at 500 °C. The sorption studies for several metal ions revealed marked high sorption efficiency of MoTiWPO4 towards Cs+ and Sr2+ ions which reached 99% and 95%, respectively. The saturation capacity of MoTiWPO4 for Cs+ and Sr2+ is 113 and 109 mg/g, respectively. MoTiWPO4 is approved to be successfully eliminating both 137Cs and 85Sr from liquid radioactive waste streams by %eff. of 92.5 and 90.3, respectively, in the presence of competing ions from 60Co(divalent) and 152Eu (trivalent), confirming the batch experiment results for the removal of Cs+ and Sr2+ metal ions. Furthermore, the decontamination factor exceeds 13.3 in the case of 137Cs and 10.3 for 85Sr.