Algal Membrane Bioreactors for Efficient Removal of Emerging Contaminants and Resource Recovery: Current Advances and Future Outlook

Abstract

Emerging contaminants (ECs), whether of synthetic or natural origin, pose a significant environmental concern, particularly in the context of industrial wastewater. The Algae Membrane Photobioreactor (AMBR) has emerged as a promising technology for ECs remediation. AMBRs effectively remove contaminants due to its considerable flexibility, scalability and a huge surface area for pollutant adsorption. The productivity and efficiency of biomass are increased when it operates in regulated conditions, which minimizes land footprint. AMBR hold immense appeal in favoring integrated circular economy approach and its implementation could achieve the goals for carbon-neutrality and resource recovery by producing value-added products like biofuels, bioplastics, biochemicals, animal feed, biofertilizers and waste re-uses. However, addressing scalability, harvesting efficiency, membrane fouling, algal strain optimization, economic viability, and regulatory approval are some of the challenges faced in order to the advancement of AMBR technology. Life cycle assessments (LCA) and techno-economic assessments (TEAs) are crucial area of future research in implementation of AMBR at pilot scale. LCA evaluates the sustainability of AMBRs with those of conventional techniques. In contrast, TEA examines economic viability parameters like cost-effectiveness, by-product market potential, and policy implications for AMBR implementation. This review emphasizes AMBR's advantages over conventional wastewater treatment technologies in detail, focusing on algal physiology responsible for ECs removal. The innovations related to the design and configuration of AMBRs are also discussed. Several benefits of this technology via integrated circular paradigm are highlighted. Noteworthy pilot case studies, LCA, TEA, challenges and future perspective are spotlighted to underscore the compelling promise of this technology.