Biofouling-resistant amidoxime-functionalized chitosan membranes enable efficient uranium recovery from salt-lake water

The limited availability of terrestrial uranium resources poses significant challenges to the development of nuclear energy. Extracting uranium from Salt Lake water offers a new solution to address the shortage of uranium resources. This study used chitosan, a naturally adsorptive material, to create chitosan microporous membranes (CS) with polyethylene glycol as a porogen. Subsequently, a novel amidoxime-based chitosan microporous membrane adsorbent (CS-AO) was developed based on CS for uranium extraction from Salt Lake water. The CS-AO membrane's hydroxyl, amino, and amidoxime groups work synergistically to provide multiple binding sites, significantly enhancing its binding capacity for UO 2 2+ . Under optimal conditions (initial concentration 3.0 mmol L −1 , temperature 323 K, pH 6), the adsorption capacity reached 2.84 mmol g −1 , with rapid adsorption/desorption rates and good selectivity. At a uranium feed concentration of 0.05 mmol L −1 and flow rate of 1.0 mL min −1 , the treatment capacity was 1046.93 L m −2 . Moreover, when applied to actual brine collected from the Chaerhan Salt Lake in Golmud, Qinghai, China for uranium extraction, CS-AO achieves an extraction rate of 79.6 %. Additionally, CS-AO showed over 90 % antibacterial effects against E. coli and S. aureus , with excellent stability, making it suitable for long-term Salt Lake uranium extraction.