Tricks and tracks in resource recovery from wastewater using bio-electrochemical systems (BES): A systematic review on recent advancements and future directions

Rapid industrialization and ameliorated lifestyle have vividly contributed to the release of huge quantity of wastewater into the environment. On the other hand, wastewater is enriched with resources like nutrients, metals, and chemicals that possess greater economic value. As a result, resource recovery from wastewater promoted ‘wastewater to wealth’ notion, thereby fostering the circular economy approach. In the recent years, bio-electrochemical systems (BES) emerged as versatile technology for simultaneous wastewater treatment and resource recovery. While the technology offers numerous advantages, its widespread commercial application has been hindered by challenges in scaling up, economical aspects, operational aspects, etc. Over the past few years, substantial efforts have been made to enhance the efficiency of electrode materials, choice of biocatalysts and design improvisations of BES. These improvements have significantly increased the performance efficiency of BES. Nevertheless, further enhancements are still necessary for BES to become economically viable. This review provides a comprehensive over view of recent developments in BES, with a particular focus on their resource recovery applications. The article covers fundamental concepts, various BES types, and the mechanisms underlying electron transfer, with a specific focus on their role in resource recovery from wastewater. Furthermore, the article delves into the challenges of scaling up BES for practical applications and provides in-depth insights into real-world applications of BES technology. The future potential of integrating phototrophic options into BES is also discussed to further enhance resource recovery and the production of value-added products.