Photo-catalytic membrane reactors for the remediation of persistent organic pollutants – A review

[Display omitted] •Photo-catalytic membrane reactors were reviewed.•The impact of the catalyst integration was benchmarked for photo catalytic membrane reactors.•The performance were compared and evaluated in light of their scalability.•The review highlights remaining challenges in the area of reactor design. A major problem that is worldwide prominent is limited access to clean water. The process of catalysis coupled with the separation process carried by catalytically active membranes, takes place in device known as a catalytic membrane reactor (CMR). In this paper, CMRs that are driven by light as external stimuli known as photo-catalytic membrane reactors (PCMRs) are comprehensively described and compared on the basis of their performance to remediate persistent organic pollutants (POPs) in the wastewater. There is rapid development in the PCMR technology in the past decade, and this review gives an overview of conventional methods employed in treatment of selected POPs and progress in the types, configuration, and operational parameters of PCMRs. The split and integrated types of photocatalytic membrane reactors, their construction techniques and properties of photo-catalytically active membranes are discussed. The PCMRs are compared on basis of degradation rate of common POPs in wastewater. Additionally, a discussion on practical application is presented with regard to major challenges and gaps in the development and up-scalability of PCMR technology.