Pushingmicrobial desalination cells towards field application: Prevailing challenges, potential mitigation strategies, and future prospects

Microbial desalination cells (MDCs) have been experimentally proven as a versatile bioelectrochemical system (BES). They have the potential to alleviate environmental pollution, reduce water scarcity and save energy and operational costs. However, MDCs alone are inadequate to realise a complete wastewater and desalination treatment at a high-efficiency performance. The assembly of identical MDC units that hydraulically and electrically connected can improve the performance better than standalone MDCs. In the same manner, the coupling of MDCs with other BES or conventional water reclamation technology has also exhibits a promising performance. However, the scaling-up effort has been slowly progressing, leading to a lack of knowledge for guiding MDC technology into practicality. Many challenges remain unsolved and should be mitigated beforeMDCs can be fully implemented in real applications. Here, we aimto provide a comprehensive chronological-based reviewthat covers technological limitations andmitigation strategies, which have been developed for standaloneMDCs. We extend our discussion on how assembled, coupled and scaled-up MDCs have improved in comparison with standalone and lab-scale MDC systems. This reviewalso outlines the prevailing challenges and potential mitigation strategies for scaling-up based on large-scale specifications and evaluates the prospects of selected MDC systems to be integrated with conventional anaerobic digestion (AD) and reverse osmosis (RO). This review offers several recommendations to promote up-scaling studies guided by the pilot scale BES and existing water reclamation technologies. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

Microbial desalination cells (MDCs) have been proven to be a versatile bioelectrochemical system with potential to alleviate environmental pollution and water scarcity. However, standalone MDCs are not sufficient for complete wastewater and desalination treatment. Connecting identical MDC units or coupling MDCs with other technologies can improve performance, but scaling-up efforts have been slow and challenges remain unresolved.