Electrospun cross-linked NaY-zeolite/PVA nanofibrous composite nanofiltration membranes for efficient Cd2+ removal from wastewater

Cadmium contamination in water poses serious environmental and health risks yet achieving high rejection with stable flux and antifouling performance remains a challenge in nanofiltration membranes. In this study, a composite nanofiltration membrane was developed by incorporating NaY zeolite into electrospun polyvinyl alcohol (PVA) nanofibers deposited on a PVDF substrate. The aim was to enhance Cd2+ removal while maintaining permeability and membrane stability. NaY zeolite was introduced in varying concentrations into the PVA matrix and crosslinked using epichlorohydrin to improve structural integrity. The incorporation of NaY provided additional active sites and a negatively charged framework, promoting Cd2+ removal primarily through adsorption and ion exchange, supported by improved hydrophilicity and selective transport pathways. Among the fabricated membranes, the optimized sample (MNaZ 5) exhibited a permeation flux of 27.3 L/m2·h, representing a ∼ 100% increase compared to the control membrane MNaZ 1 flux (12.6 L/m2·h). It also achieved 98% Cd2+ removal at an initial concentration of 5 mg/L and pH 9. In addition, the modified membranes demonstrated enhanced thermal stability and improved antifouling performance. These findings indicate that NaY zeolite-incorporated electrospun PVA/PVDF membranes offer an effective and scalable approach for Cd2+ removal from wastewater, addressing limitations of conventional nanofiltration systems.