Efficient capture of ReO4−/TcO4− on anion exchange resin from wastewater

It is still a challenge to capture TcO4− from wastewater due to its nature of non-complexing and radioactive. Herein, two types of anion exchange resins (D201 and IRA-410 resin) were selected and explore the adsorption properties for perrhenate (ReO4−, a surrogate for TcO4−). It is found that both D201 and IRA-410 resin exhibited fast adsorption kinetic (within 120 min), and superior adsorption capacity, which could reach 671.1 mg g−1 and 561.8 mg g−1 for D201 and IRA-410 resin, respectively. In addition, D201 and IRA-410 resin showed excellent selectivity for ReO4− in the presence of a variety of 1000-fold competing anions (NO2−, Cl−, SO42−, and PO43−). Importantly, the two resins still demonstrated outstanding performance after acid/alkaline soaking, calcination procedures as well as high doses of ionizing radiation, they also could remove ReO4− from simulated Hanford and SRS wastewater by automatic separation system. Finally, the anion-exchange mechanism was revealed by characterization and DFT. This work demonstrates that D201 and IRA-410 resin are efficient adsorbents for 99Tc removal from nuclear waste solutions and provides a basis for designing other novel anion exchange materials for capturing ReO4− and TcO4−.