Separation of rhenium(VII) from nuclear wastewater using N-methyl-glucosamine functionalized exchange resin

Abstract

Selective separation of 99TcO4− from nuclear wastewater can reduce discharge of 99Tc into the environment, reducing the threat to human health. However, it presents a huge challenge due to the extreme conditions combining strong alkalis, high ionic strength and strong radiation. Here, we describe an effective adsorbent prepared by anchoring N-methyl-glucosamine on styrene-divinylbenzene copolymer spheres (N-resins). N-resins retains their original properties and exhibits excellent stability in highly alkaline solutions with β radiation. Its adsorption of 99TcO4− was investigated in a non-radioactive experiment using ReO4− as an analogue for 99TcO4−. Adsorption was considered as a function of alkali solution concentration, contact time and initial concentration, and in the presence of competing anions. Results demonstrate that N-resins presents a remarkable ability to remove ReO4− from alkaline conditions. The high adsorption capacity and fast kinetics are attributed to the abundant active groups including -OH and -NH on the N resin surface. Notably, N-resins can selectively remove ReO4− from mixed solutions with high concentrations of other anions, even with a molar ratio of NO3− to ReO4−of 10,000. Moreover, N-resins can be regenerated at least 6 times without significant reduction in ReO4− adsorption, indicating that N-resins has good durability. Its excellent properties suggest it to be a promising highly effective low-cost adsorbent for removal of 99TcO4− from alkaline wastewater.