Performance evaluation of polyamide membranes infused with TiO 2 , CuS, and XG nanoparticles for enhanced wastewater treatment

Polyamide (PA)-based ultrafiltration membranes offer low-cost and energy-efficient separation for wastewater treatment. In this study, nanocomposite PA membranes were synthesized using the non-solvent induced phase inversion (NIPS) technique with controlled thickness (200–400 µm) and incorporation of 0.1 wt.% titanium dioxide (TiO2), copper sulfide (CuS), and xanthan gum (XG) nanoparticles to enhance morphology, hydrophilicity, permeability, and mechanical strength. Nanofiller addition significantly improved the permeability–selectivity balance. The PA@TiO2 membrane exhibited the highest pure water flux of 250 ± 50 L/m2h, nearly ten times higher than pure PA (25 L/m2 h), due to enhanced porosity, improved pore interconnectivity, and Ti-OH functional groups that reduced water transport resistance. The PA@CuS membrane achieved superior BSA rejection of 85.23% compared to 71.89% for pure PA, along with a reduced contact angle of 33.13°, confirming enhanced hydrophilicity. PA@TiO2 also demonstrated 68% NaCl rejection and 56% dye rejection, with effective TSS, COD, and BOD removal in synthetic wastewater. Mechanical analysis showed significant reinforcement, with PA@XG exhibiting the highest tensile strength (3755 Pa). Overall, low nanoparticle loading and scalable NIPS fabrication produced durable, high-performance membranes suitable for sustainable ultrafiltration applications.