Microbial fuel cells (MFCs) have been conceived and intensively studied as a promising technology to achieve sustainable wastewater treatment. However, doubts and debates arose in recent years regarding the technical and economic viability of this technology on a larger scale and in a real-world applications. Hence, it is time to think about and examine how to recalibrate this technology's role in a future paradigm of sustainable wastewater treatment. In the past years, many good ideas/approaches have been proposed and investigated for MFC application, but information is scattered. Various review papers were published on MFC configuration, substrates, electrode materials, separators and microbiology but there is lack of critical thinking and systematic analysis of MFC application niche in wastewater treatment. To systematically formulate a strategy of (potentially) practical MFC application and provide information to guide MFC development, this perspective has critically examined and discussed the problems and challenges for developing MFC technology, and identified a possible application niche whereby MFCs can be rationally incorporated into the treatment process. We propose integration of MFCs with other treatment technologies to form an MFC-centered treatment scheme based on thoroughly analyzing the challenges and opportunities, and discuss future efforts to be made for realizing sustainable wastewater treatment.

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Towards sustainable wastewater treatment by using microbial fuel cells-centered technologies

An overview of electrode materials in microbial fuel cells

Recent advances in the use of different substrates in microbial fuel cells toward wastewater treatment and simultaneous energy recovery

Research into alternative renewable energy generation is a priority, due to the ever-increasing concern of climate change. Microbial fuel cells (MFCs) are one potential avenue to be explored, as a partial solution towards combating the over-reliance on fossil fuel based electricity. Limitations have slowed the advancement of MFC development, including low power generation, expensive electrode materials and the inability to scale up MFCs to industrially relevant capacities. However, utilisation of new advanced electrode-materials (i.e. 2D nanomaterials), has promise to advance the field of electromicrobiology. New electrode materials coupled with a more thorough understanding of the mechanisms in which electrogenic bacteria partake in electron transfer could dramatically increase power outputs, potentially reaching the upper extremities of theoretical limits. Continued research into both the electrochemistry and microbiology is of paramount importance in order to achieve industrial-scale development of MFCs. This review gives an overview of the current field and knowledge in regards to MFCs and discusses the known mechanisms underpinning MFC technology, which allows bacteria to facilitate in electron transfer processes. This review focusses specifically on enhancing the performance of MFCs, with the key intrinsic factor currently limiting power output from MFCs being the rate of electron transfer to/from the anode; the use of advanced carbon-based materials as electrode surfaces is discussed.

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Microbial fuel cells: An overview of current technology

Bioelectrochemical metal recovery from wastewater: a review.

A novel UASB-MFC-BAF integrated system for high strength molasses wastewater treatment and bioelectricity generation.

BACKGROUND: Sulfide-containing wastewater (also containing organics) and vanadium(V)-containing wastewater exist widely and can be treated in microbial fuel cells (MFCs) based on their chemical conditions. A novel process has been investigated using MFC technologies by employing sulfide, organics and V(V) as electron donors and acceptor, respectively.



RESULTS: Electrons produced by oxidation of sulfide and organics in the anode compartment were transferred to the anode surface, then flowed to the cathode through an external circuit, where they were consumed to reduce V(V). Sulfide and total organics removal approached 84.7 ± 2.8% and 20.7 ± 2.1%, with a V(V) reduction rate of 25.3 ± 1.1%. The maximum power output obtained was 572.4 ± 18.2 mW m−2. The effects of the microbes on electricity generation as well as the products of sulfide oxidation and V(V) reduction were also evaluated and analyzed.



CONCLUSION: This process achieves both sulfide and V(V) removal with electricity generation simultaneously, providing an economical route for treating these kinds of wastewaters. Copyright © 2009 Society of Chemical Industry

Simultaneous removal of sulfide and organics with vanadium(V) reduction in microbial fuel cells

Enhanced microbial reduction of vanadium (V) in groundwater with bioelectricity from microbial fuel cells

Sulfide and vanadium (V) are pollutants commonly found in wastewaters. A novel approach has been investigated using microbial fuel cell (MFC) technologies by employing sulfide and V(V) as electron donor and acceptor, respectively. This results in oxidizing sulfide and deoxidizing V(V) simultaneously. A series of operating parameters as initial concentration, conductivity, pH, external resistance were carefully examined. The results showed that these factors greatly affected the performance of the MFCs. The average removal rates of about 82.2 and 26.1% were achieved within 72 h operation for sulfide and V(V), respectively, which were accompanied by the maximum power density of about 614.1 mW m−2 under all tested conditions. The products generated during MFC operation could be deposited, resulting in removing sulfide and V(V) from wastewaters thoroughly.

Chunhong Shi

Papers

A novel UASB-MFC-BAF integrated system for high strength molasses wastewater treatment and bioelectricity generation.

Simultaneous removal of sulfide and organics with vanadium(V) reduction in microbial fuel cells

Enhanced microbial reduction of vanadium (V) in groundwater with bioelectricity from microbial fuel cells

Factors affecting the performance of microbial fuel cells for sulfide and vanadium (V) treatment

Sulfur-based autotrophic biosystem for efficient vanadium (V) and chromium (VI) reductions in groundwater