关键词: Ultrafiltration membrane, Polysulfone, Graphene oxide, Silicon dioxide, Polyethyleneimine, Produced water

Abstract: This study synthesizes and evaluates a novel polysulfone-based membrane doped with graphene oxide-polyethyleneimine-silicon oxide (GO-SiO₂-PEI), specifically designed for oily water treatment applications. The functionalization of graphene oxide with SiO₂ and PEI was rigorously confirmed through comprehensive XRD, FTIR, Raman spectroscopy, and XPS analyses, ensuring the integrity and expected functionality of the nanocomposite. This nanocomposite was integrated into the polysulfone (PSF) membrane matrix, significantly reducing the membrane's inherent hydrophobicity and propensity for fouling. The membranes were meticulously characterized using advanced surface and bulk sensitive apparatus including contact angle and SEM imaging to ascertain their structural and functional attributes. Performance evaluations conducted in a dead-end filtration setup revealed that incorporating 1.0% (mass) of the nanocomposite into the PSF membrane markedly enhanced its porosity and improved the water contact angle. This modification led to an 809% increase in the membrane's water flux and a 57% enhancement in flux recovery rate, while still maintaining a high oil rejection rate and a relatively low leaching rate of 5.3 mg·L^-1. Analysis through the Owens-Wendt-Kaelble model indicated a significant increase in polar surface energy, corroborating the improved oil rejection capabilities at elevated flux levels. Fouling behavior, analyzed using Hermia's model, identified cake formation as the primary fouling mechanism in most of the tested membranes. Leaching tests further highlighted those membranes with higher nanocomposite loadings exhibited increased leaching rates, suggesting a trade-off between performance enhancement and material stability.

Key words: Ultrafiltration membrane, Polysulfone, Graphene oxide, Silicon dioxide, Polyethyleneimine, Produced water