Thin-Film Nanocomposite Forward Osmosis Membranes Incorporated with Hydrophilic TiO₂/Fe₃O₄ Nanoparticles: Toward Alleviated ICP

In this study, highly hydrophilic TiO₂/Fe₃O₄ nanoparticles with a high level of photocatalytic activity were used to improve the performance of thin-film nanocomposite (TFN) membranes in forward osmosis (FO) process. The influence of TiO₂/Fe₃O₄ nanoparticles binary metal oxides incorporation on the properties of the TFC FO membrane in terms of hydrophilicity, porosity, pore size, and cross-sectional morphology was thoroughly studied. Results demonstrate that with the addition of TiO₂/Fe₃O₄ nanoparticles, the structure of the membrane top layer has changed due to nanoparticles’ reaction with the amino and organic monomers in the surface polymerization process. Furthermore, the thickness of the membrane cross section has changed with the addition of TiO₂/Fe₃O₄ nanoparticles due to changes in the rate of the amine monomer penetration into the sublayer. The TiO₂/Fe₃O₄ loading caused changes in the overall porosity and improved membrane hydrophilicity. The effect of UV light on the synthesized membranes was also tested. It was found that in the presence of UV light, the high photocatalytic activity of TiO₂/Fe₃O₄ nanoparticles is the primary cause of their excellent performance in the membrane structure. As the membrane was exposed to UV light, the increase in hydrophilicity increases the membrane flux and decreases its structural parameter. These changes resulted in a 43% improvement in membrane water permeability and reduced the structural parameter up to 410 μm. Water flux of improved membrane also increased by 74% in the forward osmosis process, which was achieved without significantly decreasing membrane selectivity.