Preparation of chitosan graft benzo-15-crown-5/non-woven fabric composite membrane for enhanced Pd²⁺ adsorptive separation

Based on the selectively complexing properties of crown ethers for metal ions, a chitosan-graft-benzo-15-crown-5 ether (CTS-g-B15C5)/non-woven fabric (NWF) composite membrane with sponge-like pore structure was prepared. A flow-through dynamic adsorption method was used to investigate the adsorptive separation performance for Pd²⁺. The thermodynamic analysis revealed that Pd²⁺ adsorption on the composite membrane was a spontaneous procedure in which the high temperature would benefit the adsorption. Moreover, the composite membrane showed excellent reusability after regeneration, and there was no obvious loss of adsorption amount after five cycles. Finally, the CTS-g-B15C5/NWF composite membrane retained high selectivity for Pd²⁺ in simulated nuclear wastewater.