Applications and advancements in membrane technologies for sustainable petroleum refinery wastewater treatment

The improper discharge of oil refinery wastewater poses severe threats to ecosystems due to its hazardous compounds, highlighting the need effective treatment solutions. Membrane technologies have been successfully employed in refining plants for wastewater treatment, ensuring stability in pollutant removal and enabling water reuse. This review explores recent advances in these technologies, focusing on overcoming the critical challenge of membrane fouling, which reduces lifespan and selectivity. Advances in membrane modification, particularly through additive blending or surface coating, show promise in improving performance and fouling resistance. Additives like photocatalytic compounds (e.g., TiO₂) and graphene oxide (GO) enhance membrane stability, hydrophilicity, and anti-fouling properties. Furthermore, membrane modification through blending provides a more uniform dispersion of additives and reduces additive leaching, while the surface coating technique with adhesive additives like polydopamine can enhance mechanical stability and anti-fouling properties with greater operational simplicity. Additionally, this review highlights the recycling of reverse osmosis (RO) membranes used to provide demineralized water in refineries, typically discarded prematurely in refining plants, as a significant opportunity. Their reuse as nanofiltration (NF) or ultrafiltration (UF) membranes offers substantial economic and environmental benefits. Overall, this review underscores the potential of membrane technologies to enhance refinery wastewater treatment and suggests promising directions for future research.