Adsorption behavior of uranium on polyvinyl alcohol-g-amidoxime: Physicochemical properties, kinetic and thermodynamic aspects

Amidoxime-based adsorbents are widely studied as the main adsorbent in the recovery of uranium from seawater. However, the adsorption rate and loading capacity of such adsorbents should be further improved due to the economic viability consideration. In this paper, polyvinyl alcohol functionalized with amidoxime (PVA-g-AO) has been prepared as a new adsorbent for uranium (VI) adsorption from aqueous solution. The physicochemical properties of PVA-g-AO were investigated using infrared spectroscopy (IR), scanning electron microscope (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Results showed that the ligand monomers were successfully grafted onto the matrixes. The XRD and XPS analysis showed that uranium was adsorbed in metal ionic form rather than in crystal form. Uranyl (U (VI)) adsorption properties onto PVA-g-AO were evaluated. The adsorption of U (VI) by PVA-g-AO was fast, with an equilibrium time of less than 50 min. Additionally the maximum adsorption capacity reached 42.84 mg/g at pH 4.0.