Study on separation of ReO₄ ⁻, a substitute for TcO₄ ⁻, using functional ionic liquid impregnated extraction chromatography resins

Abstract 99 Tc has a long half-life, high fission yield, and good environmental mobility, posing a significant threat to the environment and human health. Therefore, removing technetium from radioactive wastewater is a very important and urgent task. For laboratory safety reasons, ReO 4 − is often used as a non-isotopic substitute for 99 TcO 4 − . From this point of view, the study of the separation behavior of Re in the aqueous phase can provide a reference value for the removal of 99 Tc. Here, a new type of extraction chromatography resin was prepared by impregnating the functionalized ionic liquid into the macroporous resin, whose imidazolium cations modified by amide functional groups which can effectively capture ReO 4 − /TcO 4 − from simulated radioactive wastewater. The results show the resin has good adsorption performance and fast adsorption kinetics (the adsorption equilibrium is about 20 min). The adsorption mechanism was investigated using Fourier transform infrared (FT-IR) spectra and X-ray photoelectron spectroscopy (XPS). It shows that the adsorption process is an anion exchange between Cl − in the resin and ReO 4 − in the solution.