Enhancing the efficiency of polymeric-inorganic composite mixed matrix membrane for oil/water separation via SiC decoration in the polyvinyl alcohol/glutaraldehyde framework

Oily wastewater presents a significant challenge that requires attention from the scientific community to not only treat it but also transform it into a valuable resource. Membrane-based separation techniques offer several advantages for treating oily wastewater, particularly in terms of ease of operation and lower energy requirements. The present research was aimed to develop polymeric-inorganic composite mixed matrix membranes (MMMs) for the treatment of surfactant stabilized oil-in-water (O/W) emulsions. These composite MMMs were fabricated using a non-solvent induced phase separation (NIPS) method, with polyvinyl alcohol (PVA)/glutaraldehyde (GA) serving as the matrix polymer and silicon carbide (SiC) nanoparticles incorporated into the matrix on a Nylon support. The concentrations of PVA (4, 10, and 12 wt%) and SiC nanoparticles (0, 0.1, 0.5, 1, 5, and 10 wt% relative to PVA) were varied for fabricating MMMs. In addition, other factors such as crosslinking times (10, 30, 60, and 240 min), and method of phase inversion (dry and wet) were also studied to yield the best-performing MMMs for O/W separation. The SiC content in the MMMs was found to have a significant impact on the physical characteristics of the membranes, such as surface morphology and porosity, which ultimately influenced the membrane performance. Hence, out of the six membranes tested for O/W separation, the M0.5 membrane containing 0.5 wt% SiC demonstrated high rejection (85 %) of total organic carbon (TOC) and a flux of 569.3 LMH when utilizing 100 ppm diesel O/W emulsion as the feed at 4 bar. This study underscores the potential of SiC MMMs for water treatment applications, while also emphasizing the need for further research to optimize their performance and resistance to fouling.