Uranium Extraction from Salt Water Using Formo-Phenolic Resin Containing Amido-β-phosphonic Acid Chelating Moiety

Three chelating monomers with an amido-β-phosphonic acid moiety in varying α-position groups (hydrogen, methyl, phenyl) were synthesized and incorporated into formo-phenolic type resin, resulting in six adsorbents. Characterization showed an increase in chelating monomer content with hydrophobicity. The materials exhibited similar maximum adsorption capacities (~170 mg/g) for uranium, with adsorption kinetics that varied with the α-groups and monomer percentage. The resins demonstrated good selectivity for uranium, and maintained significant adsorption capacities in synthetic seawater. They could be reused without loss of capacity, with the uranium recoverable in sulfuric acid solution.