The race between classical microbial fuel cells, sediment-microbial fuel cells, plant-microbial fuel cells, and constructed wetlands-microbial fuel cells: Applications and technology readiness level

Microbial fuel cell (MFC) is an interesting technology capable of converting the chemical energy stored in organics to electricity. It has raised high hopes among researchers and end users as the world continues to face climate change, water, energy, and land crisis. This review aims to discuss the journey of continuously progressing MFC technology from the lab to the field so far. It evaluates the historical development of MFC, and the emergence of different variants of MFC or MFC-associated other technologies such as sediment-microbial fuel cell (S-MFC), plant-microbial fuel cell (P-MFC), and integrated constructed wetlands-microbial fuel cell (CW-MFC). This review has assessed primary applications and challenges to overcome existing limitations for commercialization of these technologies. In addition, it further illustrates the design and potential applications of S-MFC, P-MFC, and CW-MFC. Lastly, the maturity and readiness of MFC, S-MFC, P-MFC, and CW-MFC for real-world implementation were assessed by multicriteria-based assessment. Wastewater treatment efficiency, bioelectricity generation efficiency, energy demand, cost investment, and scale-up potential were mainly considered as key criteria. Other sustainability criteria, such as life cycle and environmental impact assessments were also evaluated. [Display omitted] •MFC and its variant technologies S-MFC, P-MFC and CW-MFC are the promising self-sustaining bio-electrochemical systems•S-MFC, P-MFC and CW-MFC are hosted in natural environments and give larger areal dimensions to existing MFC technology•The TRL for MFC, S-MFC, P-MFC and CW-MFC achieved so far fall in the range of 5-6, 3-4, 3 and 6-7, respectively.•The cost to benefit ratio for CW-MFCs is much lower compared to MFCs under both experimental and practical conditions•CW-MFC remains leading technology compared to MFC and its inspired variants