Effective polysulfone-amorphous SiO2 NPs electrospun nanofiber membrane for high flux oil/water separation

Recently, treatment of water contaminated by petroleum fractions is a hot issue due to presence of large amounts of such waste waters. Membrane technology is the most convenient process can be exploited. In this article, polysulfone (PSF), as a widely used polymer in membranes manufacturing, was utilized to synthesize novel and effective electrospun nanofiber membranes for petroleum fractions/water separation process. The separation efficacy was enhanced by doping the PSF electrospun nanofibers by amorphous silica nanoparticles (extracted from rice husk by subcritical water technique) and graphene oxide (GO) individually. Although, addition of nano-silica and GO led to slight increase and decrease in the contact angle, respectively and all the prepared membranes (pristine, SiO2-doped, and GO-doped PSF) could be utilized successfully in the separation process, SiO2 NPs addition strongly enhanced the flux. Typically, the prepared membranes successfully separated kerosene/water, gasoline/water and hexane/water solutions into their constituents. However, in case of hexane/water, the corresponding daily flux was 23, 38 and 187 m3/m2 for pristine, GO-doped and SiO2-doped PSF nanofiber membranes, respectively. Besides enhancing the daily flux, mechanical strength tests showed that Young’s modules was enhanced by the addition of SiO2 NPs while GO has a negative influence on the mechanical properties. UV–visible spectroscopic analysis proved complete separation for the utilized mixtures. Overall, it can be claimed that the nanosilica obtained from rice husk agriculture waste can be utilized to prepare effective PSF-based electrospun nanofiber membrane for petroleum oil fractions/water with daily flux of 100, 115 and 187 m3/m2 for, gasoline, kerosene and hexane, respectively.