Phosphonic Acid-Based Organic Polymers for Efficient Uranium Removal from Strongly Acidic Waste Liquids

Efficient uranium removal from strongly acidic nuclear waste is crucial for sustainable nuclear energy, yet extreme acidity greatly challenges extraction. In order to provide a solution for uranium removal from strongly acidic waste, a phosphonic acid polymer, P(VPA-TEGDMA), was synthesized via solvothermal copolymerization of vinylphosphonic acid (VPA) and triethylene glycol dimethacrylate (TEGDMA). P(VPA-TEGDMA) demonstrated exceptional acid stability and outstanding adsorption performance for uranium in strongly acidic conditions. P(VPA-TEGDMA) achieved a maximum uranium adsorption capacity of 339.6 mg·g–1 in 4 mol L–1 HNO3, surpassing most reported adsorbents. In addition, the adsorbent exhibited good selectivity and maintained a high adsorption performance for uranium after 5 adsorption–desorption cycles. An adsorption mechanism study revealed that uranyl ions were coordinated tightly by P═O groups in the polymer. This work offers insights for designing robust phosphonic acid polymer adsorbents for uranium extraction to tackle nuclear waste management challenges in highly acidic environments.