High-capacity sorption of U(VI) from aqueous solution using a bio-based oxidized polymeric material

A novel bio-based oxidized polymeric material PAO-CIO was prepared, characterized and evaluated for its sorption toward U(VI) from aqueous solution. PAO-CIO was prepared using Cyclosorus interruptus as a novel supporter, which oxidized by sodium periodate and sodium chlorite, obtaining the oxidized particles, then surface-modified by γ-methacryloxypropyl trimethoxysilane, followed by a graft polymerization reaction and an amidoximation reaction. The SEM, TEM, XPS, FT-IR and XRD were used to characterize the adsorbent. Langmuir, Freundlich and Temkin models were appropriate for fitting the equilibrium data. According to the Langmuir model, the maximum sorption capacity (420.2   mg/g) was achieved with pH 5.0, temperature 50   °C. The sorption process was insensitive to the interference of other ions. A mixture desorption solution containing 5% NaCl (w/v) and 5% of HCl (v/v) could regenerate the U(VI)-loaded PAO-CIO completely. The sorption capacity only reduced 7.61% after six cycles compared to that of the fresh PAO-CIO. Therefore, PAO-CIO could serve as a cost-effective, efficient and novel adsorbent for U(VI) removal from aqueous solution.