Rice Husk-Derived Silicon Carbide Mixed-Matrix Membranes for Enhanced Oil-Water Emulsion Separation

In this study, a silicon carbide (SiC) mixed-matrix membrane for oil–water separation was successfully fabricated within the nanofiltration range. Silicon carbide was synthesized using rice husk ash (RHA), an agricultural waste material, combined with polydimethylsiloxane (PDMS) and subsequently incorporated into a mixed matrix membrane for oil–water separation. Polysulfone (PSF) and polyvinylpyrrolidone (PVP) were employed as polymer supports for fabricating the SiC-based mixed matrix membrane, which was tested in a dead-end filtration setup. The synthesized SiC and mixed matrix membrane were characterized using SEM-EDX, XPS, TGA, and Raman spectroscopy to evaluate their chemical and physical properties. Key operational parameters, including applied pressure, oil concentration, and membrane composition, were systematically optimized to enhance rejection efficiency. The functionalized SiC membrane exhibited outstanding performance, achieving up to 96% oil rejection at an oil concentration of 500 mg L⁻¹ and a pressure of 2 bar, with a contact angle of 36°, outperforming previously reported conventional commercial SiC-based mixed matrix membranes.