Fabrication of Thin Film Nanocomposite TiO 2 / SiO 2 ‐Polysulfone Nanofiltration Membranes for Removing Heavy Metal Ions From Wastewater

ABSTRACT Nanofiltration (NF) is critically important for removing toxic heavy metals from wastewater, providing a high‐efficiency method that safeguards public health and protects ecosystems from irreversible contamination. The main purpose of this research was to fabricate thin film nanocomposite (TFN) membranes modified with composite titanium dioxide (TiO 2 )/silica (SiO 2 ) nanoparticles for removing heavy metals. FT‐IR and XRD tests confirmed the chemical structure of the fabricated silica‐modified titania (TiO 2 /SiO 2 ). Furthermore, the Brunauer–Emmett–Teller (BET) method revealed that the composite particles possess a high specific surface area (150–250 m 2 /g). The addition of TiO 2 /SiO 2 nanoparticles up to 2 wt% induced key structural changes for the TFN membranes: water contact angle measurements indicated a sharp increase in hydrophilicity (from 68.5° to 40.4°), and AFM analysis confirmed a rise in surface roughness. The combined effect of these properties led to an obviously superior pure water flux in the TFN membranes. The membrane incorporating 1 wt% TiO 2 /SiO 2 nanoparticles (NF‐1) demonstrated exceptional performance, achieving high heavy metal rejection rates (98.84% for Pb 2+ , 91.25% for H 2 AsO 4 − , and 96.01% for Co 2+ ) alongside outstanding antifouling properties, as indicated by a 97.4% flux recovery ratio and a minimal irreversible fouling ratio. Therefore, these properties make the NF‐1 membrane a highly efficient and sustainable option for water treatment applications.