Porous Cationic Electrospun Fibers with Sufficient Adsorption Sites for Effective and Continuous ⁹⁹TcO₄⁻ Uptake

Abstract

Abstract Removal of radioactive technetium‐99 ( 99 TcO 4 − ) from water by effective adsorbents is highly desired but remains a challenge. The currently used resin adsorbents possess several obstacles, such as slow adsorption kinetics and low adsorption capacity. To address these issues, herein a type of fibrous adsorbent with porosity and hyper‐branched quaternary ammonium groups, namely porous cationic electrospun fibers (PCE fibers), is successfully prepared. PCE fibers can remove 97% of 99 TcO 4 − within 1 min and the equilibrium time of 99% removal is 20 min. The predicted maximum adsorption capacity toward the surrogate ReO 4 − can reach 826 mg g −1 , which is higher than the state of art anion‐exchange resins and most of the other reported adsorbents. Furthermore, PCE fibers have good selectivity for ReO 4 − in the presence of competitive anions, and can retain ReO 4 − uptake under extreme conditions including high acid–base and gamma irradiation. Importantly, PCE fibrous adsorptive membrane is employed for dynamic ReO 4 − removal from simulated Hanford LAW stream with a processing capacity of 600 kg simulated stream per kilogram PCE fibers. The excellent performance highlights the advantages of PCE fibers over traditional resins in technetium removal.