Novel ZnO-Modified Polyethersulfone Nanocomposite Membranes for Nanofiltration of Concentrated Textile Wastewater

This study addresses escalating textile wastewater discharge by employing silane-functionalized zinc oxide (ZnO) nanoparticles (NPs) to modify polyethersulfone (PES) membranes, resulting in innovative nanocomposites. ZnO NP integration into the PES matrix, ranging from 0 to 2 wt.%, was systematically varied and characterized using FTIR, EDX, pore size measurements, contact angles, and FESEM. The investigation confirms substantial influence of silane-functionalized ZnO NPs on PES membrane surface properties, manifesting in morphological changes, denser structures, and enhanced hydrophilicity, reducing contact angles from 67.5° to 47.9° for M0 and M4, respectively. Despite a twofold increase in mean pore size from 2.3 to 3.98 nm due to ZnO NP incorporation, separation capabilities of nanocomposite membranes remained unaffected. Porosity progressively improved with higher ZnO content. Optimally, 1.5 wt.% ZnO content notably increased pure water flux from 25 to 53 L/m2.h, while demonstrating robust antifouling properties and maintaining high separation rates. These findings highlight the potential of ZnO-modified nanocomposite membranes for diverse dye-containing wastewater treatment, suggesting a viable solution in environmental remediation.