Cerium oxide nanoparticles embedded thin-film nanocomposite nanofiltration membrane for water treatment

In this paper, a new approach to synthesize thin-film nanocomposite membranes using cerium oxide (CeO₂) nanoparticles (NPs) by pre-seeding interfacial polymerization method was reported. Prepared membranes were examined using contact angle, molecular weight cut-off (MWCO), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and scanning probe microscopy (SPM) to observe its hydrophilicity, pore size, morphology, surface chemistry, and roughness, respectively. Surface charges of the prepared membranes were also qualitatively calculated with the help of contact angle measurements by using the Grahame equation. MWCO studies revealed >90% polyethylene glycol (M.W. 1500 Da) rejection, which was fitted in the range of nanofiltration. By increasing the concentration of CeO₂ NPs, flux (33.12 to 41.28 L/m²h), hydrophilicity (77.3 to 51.1°) and surface charges (-7.58 to -13.39 mC/m²) of the membranes was successfully improved, and also showed the high (>90%) salt rejections. The CeO₂ embedded membrane was also found out in successful prevention from the attack of bacteria (Escherichia coli) compared to pure polyamide (PA) membrane and confirmed through SEM and viable cell count method. The membrane performances were also evaluated using seawater for fouling study and found that CeO₂ embedded surface increased the rejection of hydrophobic contaminants, and notably reduced the fouling.