Polyvinylchloride Ultrafiltration Membranes Modified with Different SiO 2 Particles and Their Antifouling Mechanism for Oil Extraction Wastewater

Novel low-cost and antifouling polyvinylchloride (PVC)-based membranes were fabricated with regular and hydrophilic nano-SiO2 particles as additives. The modified membranes exhibited significant improvements in mechanical properties, surface hydrophilicities, and antifouling performances in filtration of oil extraction wastewater. The addition of two types of nano-SiO2 particles increased the quantities of hydrophilic functional groups on the surface of the PVC membranes, which enhanced the resistance to adsorption of oily hydrophobic contaminants. Compared with the unmodified membrane, the membranes modified by regular and hydrophilic nano-SiO2 (at optimal addition of 1.5 g) presented more steady initial fluxes and higher flux recovery ratios in every filtration cycle. Meanwhile, both modified membranes exhibited high removal efficiencies of suspended solids (more than 98%) and oil components (up to 95%). These findings indicate that PVC membranes modified with two types of nano-SiO2 particles have great potential for applications in the reuse of oil extraction wastewater.