Separation of ReO₄ ⁻/TcO₄ ⁻ from simulated radioactive waste liquid by a novel series of anion exchange resins

Abstract

Selective removal of 99TcO₄− from radioactive wastewater is a challenging but significant task, which benefits spent fuel reprocessing and radioactive-waste leakage treatment. This work introduces the performance of adsorption ReO4 − using a series of novel anion exchange resins, namely MAPE-1, MAPE-2, MAPE-3, and MAGD-1, impregnated with functionalized ionic liquids as active sites. They exhibit a high selectivity towards TcO₄−/ReO₄−, in a wide pH range of pH 5–11 for ReO₄−/TcO₄− adsorption. Among these resins, MAPE-1 has the best adsorption performance for ReO4 −, with a maximum adsorption capacity of 202.4 mg/g and a high distribution ratio K d of 6.2 × 10⁶ mL/g at pH 7. The adsorption mechanism involves anion exchange between functionalized ionic liquids and TcO₄−/ReO₄−, which is supported by X-ray energy dispersive spectroscopy (EDS) and Fourier Transform Infrared spectroscopy (FT-IR) analyses. In addition, X-ray photoelectron spectroscopy (XPS) further illustrates the interaction between the resin and perrhenate.