Preparation and characterization of PSF/PEI/CaCO 3 nanocomposite membranes for oil/water separation

Abstract

Ultrafiltration (UF) is one of the significant advanced processes for oily wastewater treatment due to its clear advantages, for instance, ease in operation and efficient separation. The main drawback of these processes is the fouling problem and many researchers' effort on fabrication of high-performance membranes with higher hydrophilicity and antifouling properties. In this study, flat-sheet polysulfone (PSF)/polyethylenimine (PEI)/CaCO₃ nanocomposite membranes were prepared by phase inversion method for oil/water emulsion separation. Structural properties of membranes were characterized by SEM, FT-IR, contact angle, tensile strength, and atomic force microscopy analysis. Increasing the CaCO₃ nanoparticle loading exhibited the increased the water flux and BSA rejection. PSF/PEI/10 wt% CaCO₃ nanocomposite membranes have 145 L/m² h water flux at 2 bar with a contact angle of 84° and with 92% BSA rejection. All prepared CaCO₃ nanocomposite membranes reached similar oil rejections at above 90%. Besides the higher water flux and oil removal efficiencies, 10 wt% of CaCO₃ nanoparticle-blended PSF membranes has notable antifouling capacity with the highest flux recovery ratio (FRR) and lowest flux decay ratio (DR) values. The results showed that there is a great potential to use PSF/PEI/CaCO₃ nanocomposite membranes for the treatment of oil water emulsions with higher permeability and antifouling capacity.