A novel mesoporous material for uranium extraction, dihydroimidazole functionalized SBA-15

Abstract

Due to the rapid development of the nuclear power industry, and consequently, the nuclear accident in Fukushima, much attention has been paid to novel materials for the efficient and rapid separation, removal and recovery of nuclear fuel associated radionuclides from aqueous solutions. Herein, a novel mesoporous material, dihydroimidazole functionalized SBA-15 (DIMS), was synthesized via a post-grafting method and used as an efficient sorbent for the extraction of U(VI) from aqueous solution. The synthesized material was found to possess highly ordered mesoporous structures with a large surface area and a uniform pore diameter. The sorption tests under various conditions demonstrated that the sorption of U(VI) by DIMS was fast, with an equilibrium time of less than 10 min. Additionally, the maximum sorption capacity reached 268 mg g⁻¹ at pH 5.0 ± 0.1. Changes in the solid-to-liquid ratio (m_sorbent/V_solution) did not have any remarkable effect on the U(VI) sorption. Besides, the sorbed U(VI) can be easily desorbed by 0.01 mol L⁻¹ or more concentrated HNO₃ solution, resulting in a U(VI) solution with a concentration factor of 300 at a solid–liquid ratio as low as 0.013 g L⁻¹. The reclaimed sorbent can be reused with no obvious decrease in the sorption capacity. The selectivity of the DIMS sorbent for U(VI) ions was found to be fairly desirable by the sorption tests with the solutions containing a range of competing metal ions.