Polyethyleneimine-functionalized β-cyclodextrin porous polymers for enhanced elimination of U(vi) from wastewater

Abstract

Finding effective methods and materials for treating radioactive waste water is urgent to combat environmental issues. A new polyethyleneimine-functionalized β-cyclodextrin porous polymer (PEI-PCDP), which was used for fast and efficient elimination of uranium (U(VI)) from nuclear wastewater, was successfully synthesized in this work. It was found that there were a lot of amine/imide groups on the PEI-PCDP surface through X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and specific surface areas (BET), and it displayed an irregular porous network construction with a BET of 82.816 m² g⁻¹. Static adsorption results revealed that PEI-PCDP has a large adsorption quantity on U(VI), and the maximum theoretical adsorption quantity was 757.40 mg g⁻¹. Meanwhile, kinetic results exhibited rapid adsorption, and the adsorption quantity can reach 80 ± 1% of the equilibrium adsorption quantity in 10 min. Moreover, PEI-PCDP exhibited good regeneration ability. After 5 sorption–desorption cycles, the adsorption quantity decreased by 10.6%. Mechanism analysis via XPS illustrated that the adsorption process was principally attributed to the active site co-constructed by rich oxygen-containing functional groups and multi-amine groups (–NH₂, –NH–) in PEI. Hence, PEI-PCDP has striking U(VI) removal performance and has potential application prospects in radioactive wastewater treatment.