Recyclability and life time analysis of potent antifouling PVDF nanohybrid membranes for produced water treatment

Poly (vinylidene fluoride) (PVDF) is an outstanding polymeric material that is widely applied for the development of ultrafiltration (UF) membranes. However, due to its hydrophobicity, it reveals underperformance when applied for the waste water treatment. In order to boost the hydrophilicity, morphology and permeance of the membrane, certain surface modifications have been carried out by blending PVDF with hydrophilic polymer cellulose acetate (CA) and silica (SiO₂) nanoparticles. PVDF was incorporated with SiO₂/CA in varying compositions for the preparation of PVDF/SiO₂/CA membrane via non-solvent induced phase separation (NIPS) method for produced oily wastewater treatment. The prepared membranes were characterized using attenuated total reflectance–Fourier transform infrared spectroscopy (ATR–FTIR), scanning electron microscopy (SEM), atomic force microscopy (AFM), thermogravimetric analysis (TGA), mechanical test analyzer, molecular weight cutoff (MWCO), and contact angle. The performance of the prepared membranes were evaluated by conducting flux studies using pure water, rejection, antifouling and recyclability studies for the treatment of oily wastewater. The PVDF (15.5 wt%)/CA (1 wt%)/SiO₂ (0.75 wt%) MM-3 membrane exhibits improved surface roughness, higher hydrophilicity, permeability due to the enhanced pore formation, and better pore size distribution without degrading its performance in terms of oil rejection efficiency. Better Pure water flux (PWF) of 418.54 L m⁻² h⁻¹ and permeate flux of 374 L m⁻² h⁻¹ was shown by the MM-3 membrane. The MM-3 membrane exhibits 96% rejection with excellent antifouling properties. As a result, the composition of the MM-3 membrane is proven better for segregating oil from an oil–water emulsion.