A high absorbent PVDF composite membrane based on β-cyclodextrin and ZIF-8 for rapid removing of heavy metal ions

• In situ synthesis of β-CD@ZIF-8 nanoparticles on PVDF membrane pore walls. • High adsorption capacity and fast adsorption rate. • Recyclable and highly reusable. With accelerated industrial development and serious environmental issues, removing heavy metal ions from industrial discharge effluents is a significant subject. In the present paper, a novel absorbent polyvinylidene fluoride (PVDF) composite membrane based on β-cyclodextrin and zeolitic imidazole skeleton-8 (β-CD@ZIF-8) nanoparticles was prepared through the deep-permeation method. The nanoparticles are assembled in situ in PVDF membrane pores and anchored in each membrane pore along the membrane thickness direction. The batch adsorption experiment and characterization analysis were conducted to further investigate the performance of the composite membrane for the removal of Pb 2+ and Cu 2+ from wastewater. The results showed that the saturation adsorption capacities of β-CD@ZIF-8/PVDF micro membrane adsorbers for Pb 2+ and Cu 2+ were 708.130 and 651.379 mg/g, respectively, which were remarkably higher than those of powder materials of β-CD@ZIF-8 and other porous materials due to the intensified contact within the confined space and more active sites provided within the membrane pores. The novel absorbent membrane behaved with excellent absorption capacity, demonstrating the tremendous potential for industrial applications.