Microbial Fuel Cell MFC

The anodic chamber of MFC contains microbes that oxidise the substrates (glucose, etc.) and electrons/protons are generated along with carbon dioxide as an oxidation product. 

From Eq. (1.42), it can be inferred that the substrate breaks down into carbon dioxide and proton along with electricity as a by-product. The concept of MFC was demonstrated by Potter in 1910, who used platinum electrodes as well as living cultures of Escherichia coli and Saccharomyces. The anodophile species of the microbes can transfer the electrons directly to the anode. Otherwise, the electron mediators are required in the cell for enhanced power output and increased efficiency. The direct electron transfer to the anode is hindered by a majority of microbial species due to the presence of non-conductive Upopolysaccharides, peptididoglycans and lipid membrane in their outer layers. Hence, mediators are used which capture electrons from the membrane and are reduced. Furthermore, these mediators will again become oxidised once they move across the membrane and release the electrons to the anode. Hence, the electron transfer process keeps the anode replenished which maintains the sustainability of cell. Anthraquinone-2, 6-disulphonate, 2-methylene blue, thionine, 2-hydroxy-l, 4-naphthoquinone, Fe (III) EDTA, Meldola s blue and neutral red are some of the common chemical mediators which enhance electricity production. MFC is known as the 

Anode Membrane cathode Fig. 1.17 The sehematie of microbial fuel cells 

Some microbial metabolites/endogenous mediators are used as mediators by microbes. Some microbes such as Rhodoferax ferrireducens, Geobacter metal-lireducens, Shewanella putrefaciens and Geo-bacteriaceae sulferreducens are bioelectrochemically active. These microbes directly transfer electrons via the membrane. They have the capability to form a biofilm on the anode surface. Hence, in the presence of these microbes the anodes act as an electron acceptor. 

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The so-called microbial fuel cells (MFC) are a completely different type of fuel cell. Here, bacteria are used to convert a bio-usable substrate directly into electricity. In the future, it might be possible to run an MFC for medical purposes by using glucose directly from the patient s bloodstream (Logan et al., 2006). 

Karra, U. et al.. Power generation and organics removal from wastewater using activated carbon nanofiber (ACNF) microbial fuel cells (MFCs). Int. J. Hydrogen Ener. 2012. 

Carbon felt is another kind of CF arrange, generally used as thermal insulation in inert and vacuum furnaces, and that has seen its use in the fuel cell area only in microbial fuel cells (MFC) [101]. 

Biomass is one t5rpe of carbon-neutral, renewable energy source and has been considered for an attractive resource during the past few decades due to its abundance in the world. Microbial fuel cell (MFC) is one approach to utilize the abundant biomass, and it has the advantage of directly converting biomass into electricity with high columbic efficiency over traditional biomass utilization approaches, such as incineration, gasification, fermentation, etc. 

Ren H, Rangaswami S, Lee H-S, Chae J (2013) A micro-scale microbial fuel cell (MFC) having ultramicroelectrode (UME) anode. In Micro electro mechanical systems (MEMS), 2013 I.E. 26th international conference on. IEEE, pp 869-872... 

Pant, D., van Bogaert, G., Diels, L., Vanbroekhoven, K. (2010). A review of the substrates used in microbial fuel cells (MFCs) for sustainable energy production. Bioresource Technology, 101, 1533-1543. 

A new group of fuel cell is microbial fuel cells (MFCs), which is a novel technology that produces electricity using bacteria as electrocatalysts. The performance of MFCs is influenced by the type of electrode, the electrode distance, the type and surface area of their membrane, their substrate and their microorganisms. The most common catalyst used in cathodes is platinum (Pt). Ghasemi et al. applied chemically and physically activated carbon nanofibers as an alternative cathode catalyst to platinum in a two-chamber microbial fuel cell for the first time [155]. 

Microbial fuel cells (MFCs), in general work like a PEMFC, but bacteria are responsible for the oxidation reaction. 

Zhuang L, Zheng Y, Zhou S, Yuan Y, Yuan H, Chen Y. Scalable microbial fuel cell (MFC) stack for continuous real wastewater treatment. Bioresour Technol 2012 106 82-88. 

The successful application of microbial fuel cells (MFCs) and bioelectrochemical systems (BBSs) requires an understanding, and ultimately the optimization, of microbial activities associated with the bioelectrocatalytic conversion of chemical and electrical inputs. Researchers must always consider that MFC/BES reactors utilize living microorganisms to drive catalytic activity, and these microbes will respond to system changes in different ways than abiotic catalysts. 

Microbial Fuel Cell (MFC) e"[V) Microbial Electrolysis Cell (MEC) E (V) Water Electrolysis E (V)... 

A microbial electrolysis cell is based on the concept of a microbial fuel cell (MFC) and consists of an anode and cathode chamber, a membrane that electrically separates the electrodes, and an external power supply [8] (Fig. 1). The anodic reaction is the same as in a microbial fuel cell ElectrochemicaUy active microorganisms oxidize organic compounds such as acetate, generating carbon dioxide (CO2), protons (H" ), and electrons (e ), using the anode as terminal... 

A bioelectrochemical system (BES) is an electrochemical device used to convert electrical energy into chemical energy and vice versa. A BES consists of an anode and a cathode compartment, often separated by an ion-selective membrane. The anode is the site of the oxidation reaction which liberates electrons to the electrode and protons to the electrolyte the cathode is the site of the reduction reaction, which consumes the electrons to reduce a final electron acceptor. To maintain electroneutrality of the system, protons (or other cations) need to migrate to the cathode through the ion-selective membrane. Depending on the half-cell potentials of the electrodes, a BES can be operated either as a microbial fuel cell (MFC), in which electric energy is generated, or as a microbial... 

A microbial fuel cell (MFC) or biological fuel cell is a biochemical system that drives a current by using and copying bacterial interactions found in nature. It is a device that converts chemical energy to electrical energy by the catalytic reaction of micro-organisms, usually bacteria. 

Electrode materials play an important role in the performance (power output) and cost of bacterial fuel cells. This problem was the topic of two review papers. In a review by Rismani-Yazdi et al. (2008), some aspects of cathodic limitations (ohmic and mass transport losses, substrate crossover, etc.), are discussed. In a review by Zhou et al. (2011), recent progress in anode and cathode and filling materials as three-dimensional electrodes for microbial fuel cells (MFCs) has been reviewed systematically, resulting in comprehensive insights into the characteristics, options, modifications, and evaluations of the electrode materials and their effects on various actual wastewater treatments. Some existing problems of electrode materials in current MFCs are summarized, and the outlook for future development is also suggested. 

Figure 8.1. Illustration of a typical two-chamber microbial fuel cell (MFC) specific bacteria species in the anode chamber, named exoelectrogenic or anode-respiring bacteria (ARB), break down organic substrates, i.e., acetate, to produce electrons, protons, and CO2. The electrons pass through an external resistor to be reduced at the cathode while protons pass through the proton exchange membrane (PEM) from the anode to the cathode chamber.

Choi, S. Chae, I Optimal biofilm formation and power generation in a micro-sized microbial fuel-cell (MFC). Sensor. Actuator. A Physical 195 (2013), pp. 206-212. 

Jiang, D. Li, B. Novel electrode materials to enhance the bacterial adhesion and increase the power generation in microbial fuel-cells (MFCs). Water Sci. Technol. 59 (2009), pp. 557-563. 

Kargi, F. Eker, S. Electricity generation with simultaneous wastewater treatment by a microbial fuel-cell (MFC) with Cu and Cu-Au electrodes. J. Chem. Technol. Biotechnol. 82 2001), pp. 658-662. 

A microbial fuel cell (MFC) is a device that uses microbes to convert chemical energy stored in organic or inorganic matter into electrical energy. For nearly a century it has been known that bacteria can generate electrical current [1]. However, it is only within the last decade that MFCs have drawn much research attention for their potential applications in energy generation from wastewater... 

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