A new type of thin-film nanocomposite (TFN) membrane was synthesized by incorporating cellulose nanocrystals (CNCs) into a polyvinyl alcohol (PVA) top layer on a polycarbonate (PC) substrate via dip-coating. The synthesized TFC and TFN membranes (PC/PVA TFC and PC/PVA-CNC TFN membranes) were evaluated using contact angle measurement, field emission scanning electron microscopy (FE-SEM), and atomic force microscopy (AFM). All membranes were applied in a cross-flow filtration system for oily wastewater treatment. The results showed that the membranes' hydrophilicity increased significantly when 0.1 wt.% CNC was used. The water flux for the PC/PVA TFC membrane was measured at 19.5 L/m2·h, while the flux for the PC/PVA-CNC 0.05% TFN membrane was 34.7 L/m2 h, demonstrating a substantial increase in permeability. FE-SEM investigations revealed the existence of an active layer on both the PC/PVA TFC and PC/PVA-CNC TFN membranes, with corresponding thicknesses of 235 and 170 nm, respectively. The total organic carbon (TOC) concentration for the PC/PVA TFC membrane was 30.2 mg/L, which decreased to 21.3 mg/L and 22.6 mg/L for the TFN-CNC 0.05% and TFN-CNC 0.1% membranes, respectively. This study highlights the potential of CNC-enhanced TFN membranes to improve the performance and longevity of membrane filtration systems in treating oily wastewater, offering significant implications for environmental sustainability and industrial applications.
