Removal of Contaminants of Emerging Concern from Wastewater Using Photocatalytic Membranes: Current Status and Challenges

The increasing presence of contaminants of emerging concern (CECs) in surface and groundwater is a global concern due to their toxicity, persistence, and bioaccumulation, which lead to undesired effects. Conventional wastewater treatment processes are unable to remove these CECs, necessitating advanced treatment strategies to remove them effectively. Among advanced strategies, photocatalytic membrane treatment has attracted considerable interest among researchers. This review critically examines the fundamental principles governing the performance of photocatalytic membranes. It identifies significant challenges, including photocatalyst leaching, light accessibility, intermediates' toxicity, and scalability of synthesis and immobilisation techniques. It explains why these factors significantly hinder long-term stability, scalability, and practical deployment of photocatalytic membrane systems and provides potential solutions. Through gap analysis, the review has identified rigorous techno-economic analysis, real-world wastewater validation, and systematic toxicity assessment of degradation intermediates as areas of further study. These targeted actions provide clear pathways to enhance the viability, safety, and commercial readiness of photocatalytic membrane systems.