High stability and performance of organic pollutant removal using PVDF-TiO2 fabricated by non-solvent Induced phase separation process

The present study aims to prepare, characterize, and evaluate the performance of polyvinylidene fluoride (PVDF) and PVDF-TiO 2 membranes prepared using the non-solvent induced phase separation technique.The influence of titanium dioxide (TiO 2 ) loading on membrane morphology, surface characteristics, and filtration behavior will systematically be examined.The membrane performance was assessed using both single-dye and binarydye systems, using a single-based system of methylene blue as a cationic dye and acid yellow 17 as an anionic dye, and a binary-based system of mixed methylene blue-acid yellow 17.The results show that the pristine PVDF membrane has the morphology of an interconnected pore network due to the effect of the solvent-nonsolvent exchange process.Further investigation also shows that the surface membrane has micropores where the incorporation of nanosized TiO 2 reduces the pore size by coating and filling the membrane under optimum conditions, while excessive TiO 2 leads to agglomeration, which negatively affects the mechanical stability, material hydrophilicity, and dye removal efficiency.The membrane containing a 10% ratio of TiO 2 (w/w) compared to PVDF weight exhibited the best overall performance, achieving removal efficiencies of 87.53% for methylene blue and 53.29% for acid yellow 17 in a single-dye filtration system.In the binary system, the rejection slightly decreased to 84.67% for methylene blue, whereas acid yellow 17 removal increased to 66.31%.These results suggest that separation in single-dye systems is primarily governed by electrostatic interactions between the dye molecules and the membrane surface, while binary systems involve a combination of size exclusion and chargebased interactions.These findings open the possibilities of the optimum condition to treat the complex wastewater, especially for those with large particle removal.The study also demonstrates that PVDF-TiO 2 membranes are a suitable option for membrane since they has good mechanical and physical properties, are easy to prepare, and provide a promising potential for complex wastewater treatment applications.