Evaluation of a Nanohybrid Membrane (PSF/ZnO) Efficiency in Natural Organic Matter Removal From Water

Abstract

Background: Natural organic matter (NOM) in drinking water sources has always been regarded as a precursor for the formation of trihalomethanes (THMs), haloacetic acids (HAAs), and carcinogenic properties. This study aimed to fabricate and characterize a nanohybrid ultrafiltration membrane (PSF/ZnO) to evaluate its efficiency in NOM removal from water. Methods: Nanohybrid membranes with ratios of 0, 1, 2, 3 and 4% w/w of ZnO nanoparticles (NPs) were fabricated using the phase inversion method and characterized by the contact angle, AFM, FTIR, and SEM analyses. In this study, the effects of initial humic acid (HA) concentration, operating pressure, pH, and filtration time were examined on the HA removal efficiency and pure water flux through the membrane. Results: The results showed that addition of the ZnO NPs to the PSF membrane reduced the contact angle on the PSF/ZnO nanohybrid membrane’s surface. According to FE-SEM images, increasing the ZnO concentration changed the porous structure of the membranes from a spongy, teardrop shape to a finger-like channel structure. The FTIR analysis revealed an increase in the hydrophilicity of the membrane due to the presence of hydroxyl functional groups in ZnO. AFM images indicated an increase in the surface roughness of nanoparticle-containing membranes. It was found that an increase in the concentration of the ZnO NPs (0-4% w/w) increased HA removal efficiency (43.63-83.4%). Conclusion: This study demonstrated that the use of the PSF/ZnO nanohybrid membranes increased HA removal efficiency and pure water flux passing through the membrane.