3. Microbial Fuel Cells : Novel Biotechnology For Energy Generation Microbial fuel cells (MFCs) have emerged in recent years as a promising yet challenging technology. MFCs are the major type of bioelectrochemical systems (BESs). MFC is considered to be a promising sustainable technology to meet increasing energy needs. MFC can generate electricity and accomplish wastewater treatment simultaneously It may offset the operational costs of wastewater treatment. Microbial fuel cells (MFCs) have emerged in recent years as a promising yet challenging technology. MFCs are the major type of bioelectrochemical systems (BESs). MFC is considered to be a promising sustainable technology to meet increasing energy needs. MFC can generate electricity and accomplish wastewater treatment simultaneously It may offset the operational costs of wastewater treatment.

4. The knowledge that bacteria can generate electric current was first reported by Potter (1911). Very few practical advances were achieved in this field even 55 years later (Lewis 1966). In the early 1990s, fuel cells became of more interest and work on MFCs began to increase (Allen and Bennett0 1993). The first air-cathode MFC was reported by Sell et al. (1989). The breakthrough in MFCs occurred in 1999 when it was recognized that mediators did not need to be added (Kim et al. 1999a; Kim et al. 1999b).

5. Microbial Fuel Cells (MFCs) Have Gained A Lot Of Attention In Recent Years The number of articles on MFCs. The data is based on the number of articles mentioning MFC in the citation database Scopus in September’ 2009

6. Anode Membrane Catho de

7. Cell MOMO MRMR e-e- e-e- e-e- H+H+ H + H+H+ O2O2 H2OH2O e-e- e-e- e-e- e-e- e-e-

8. Microbial Fuel Cells and Parameters Affecting Performance

9. Microbial Fuel Cell : Substrate Substrate is regarded as one of the most important biological factors. A great variety of substrates can be used in MFCs ranging from pure compounds to complex mixtures of organic matter present in wastewater. The substrate influences not only the integral composition of the bacterial community in anode, but also the MFC performance. Substrate is regarded as one of the most important biological factors. A great variety of substrates can be used in MFCs ranging from pure compounds to complex mixtures of organic matter present in wastewater. The substrate influences not only the integral composition of the bacterial community in anode, but also the MFC performance.

10. Microbial Fuel Cell : Substrate Simple Substrates: Acetate Glucose... Complex Substrates: Municipal Wastewater Industrial Wastewater Brewery Wastewater Chocolate wastewater Starch Processing Wastewater Dye Wastewater... Landfill Leachates Lignocellulosic Biomass... Simple Substrates: Acetate Glucose... Complex Substrates: Municipal Wastewater Industrial Wastewater Brewery Wastewater Chocolate wastewater Starch Processing Wastewater Dye Wastewater... Landfill Leachates Lignocellulosic Biomass...

11. pH Gradient: Important Bottleneck Anodic Reaction Important limiting steps in anode : transport in the biofilm transport throw the proton exchange membrane Shifts microbial community Anodic potential reduction Cathodic Reaction A pH increase at the cathode, which can negatively affect the cell performance. Cathodic potential reduction Clauwaert, P., et al., Minimizing losses in bio-electrochemical systems: the road to applications.. Appl. Microbiol. Biotechnol., 2008. 79: p. 901–913 Zhuang, L., et al., Enhanced performance of air-cathode two-chamber microbial fuel cells with high-pH anode and low-pH cathode. Bioresource Technology, 2010. 101: p. 3514–3519.

12. Unwanted pH Gradient :Solution Well-buffered solution offset pH changes. Use of Membraneless structure (single chamber). Use of some membrane alternatives (diffusion layer). Well-buffered solution offset pH changes. Use of Membraneless structure (single chamber). Use of some membrane alternatives (diffusion layer). Zhuang, L., et al., Enhanced performance of air-cathode two-chamber microbial fuel cells with high-pH anode and low-pH cathode. Bioresource Technology, 2010. 101: p. 3514–3519

13. Conclusion:

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