A simple phosphorylation modification of hydrothermally cross-linked chitosan for selective and efficient removal of U(VI)

In this paper, novel phosphorylated hydrothermally cross-linked chitosan (HCC-PO4) was prepared by simple hydrothermal cross-linking technology. The prepared adsorbents were characterized by SEM, XRD, and FT-IR, etc., which proved that -PO4 was successfully introduced into the hydrothermally cross-linked chitosan (HCC). Batch experiments were carried out to investigate the adsorption process of U(VI) on the adsorbent. It was found that the theoretical maximum U(VI)-adsorption capacity of HCC-PO4 was 384.6 mg-g(-1) at 298.15 K and pH 5.5. HCC-PO4 still had adsorption selectivity as high as 71.5% in a competitive ion system. In addition, HCC-PO4 maintained 85.4% of its original adsorption capacity after 5 adsorption-desorption cycles. On account of the high selectivity and high U(VI)-adsorption capacity, HCC-PO4 showed promise in removing U(VI) in wastewater in actual production.