Branched Fibrous Amidoxime Adsorbent with Ultrafast Adsorption Rate and High Amidoxime Utilization for Uranium Extraction from Seawater

Direct collection of uranium from low-uranium systems via adsorption remains challenging. Fibrous sorbent materials with amidoxime (AO) groups are promising adsorbents for uranium extraction from seawater. However, low AO adsorption group utilization remains an issue . Herein, we We herein fabricated a branched structure containing AO groups on polypropylene/polyethylene spun-laced nonwoven (PP/PE SNW) fibers using grafting polymerization induced by radiation (RIGP) to improve AO utilization. The chemical structures, thermal properties, and surface morphologies of the raw and treated PP/PE SNW fibers were studied. The results show that an adsorptive functional layer with a branching structure was successfully anchored to the fiber surface. The adsorption properties were investigated using batch adsorption experiments in simulated seawater with an initial uranium concentration of 500 μg·L-1 (pH 4, 25 °C). The maximum adsorption capacity of the adsorbent material was 137.3 mg·g-1 within 24 h; moreover, the uranyl removal reached 96% within 240 min. The adsorbent had an AO utilization rate of 1/3.5 and was stable over a pH range of 4–10, with good selectivity and reusability, demonstrating its potential for seawater uranium extraction.