Bioinspired succinyl-β-cyclodextrin membranes for enhanced uranium extraction and reclamation

Abstract

Uranium (U) is the main raw material in the nuclear industry and is also one of the most hazardous contaminants because of its radioactivity and chemical toxicity. In this study, we present a highly selective and efficient strategy for U(VI) separation and recovery by using a succinyl-β-cyclodextrin-based membrane (SβCDM). The prepared SβCDM achieved equilibrium in 60 min and the equilibrium isotherm was fitted well by the Langmuir model with a maximum U(VI) capacity of 378.8 mg g⁻¹. The maximum dynamic adsorption capacity of SβCDM reached 500.0 mg g⁻¹ under 1 bar operation pressure within 20 min. Moreover, SβCDM could be easily regenerated with a U(VI) recovery of 90% even after ten adsorption–desorption cycles. Noteworthily, SβCDM exhibited a high selectivity for U(VI) when other competitive metal ions and anions existed. The density functional theory (DFT) calculations and extended X-ray absorption fine structure studies demonstrated that the synergistic spatial effect and coordinate effect boosted the overall uranyl affinity of SβCDM. We also prepared membrane modules with great U(VI) adsorption performance in natural seawater. These findings highlight many advantages of SβCDM over traditional membrane-type adsorbents in U(VI) extraction.