Bacterial fuel cell

Examples of bacterial fuel cells are presented in Table 3. Of the fuel cells noted, the production of hydrogen as an end product of bacterial metabolism appears to be the most useful biological mechanism for use in electrochemical energy conversion. 

However, in their mechanism and in their action nature bacterial and enzymatic fuel cells have much in common. In bacterial fuel cells intermediate redox systems are often used, as well, to facilitate electron transfer to (or from) the substrate. As the effect of microorganisms is much less specific than that of enzymes, a much wider selection of redox systems can be used, in particular, the simplest iron(III)/iron(II) system. The working conditions of these two kinds of biological fuel cells are similar as well a solution with pH around 7.0 and a moderate temperature, close to room temperature. 

Niessen, J., U. Schroder, M. Rosenbaum, and F. Scholz. 2004. Fluorinated polyanilines as superior materials for electrocatalytic anodes in bacterial fuel cells. Electrochem Commun 6 (6) 571-575. 

The Massachusetts scientists constructed a bacterial fuel cell using graphite electrodes. The Geobacter grow naturally on the surface of the electrode, forming a stable biofilm. The overall reaction is... 

A bacterial fuel cell. The blowup shows the scanning electron micrograph of the bacteria grow ng on a graphite anode. The fritted disc allows the ions to pass between the compartments. 

Tests involving a bacterial fuel cell with anode and cathode compartments separated by a cation-exchange membrane were reported by Zhang et al. (2006). The compartments were filled with phosphate buffer solution at pH 7. In addition. 

Another version of a bacterial fuel cell that worked with sugar industry effluents was described by Prasad et al. (2006). A culture of Clostridium sporogenes was used in the anodic part of the cell, and a culture of Thiobacillus ferrooxidans was used in the cathodic part. The OCV was 0.83 V and the maximum energy density was about 4 p,W/cm. ... 

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. 

This is the first report to describe the collection of gas under pressure in a biosystem. This finding is of great interest as it would permit the distribution of H 2 to some utilities without any use of pumping systems. For example, H2 could be conveniently distributed to fuel cells. This bacterial strain is still under investigation with a view to better exploitation of its properties. 

To synthesize a low cost proton conductive membrane from bacterial cellulose for polymer electrolyte membrane (PEM) fuel cells. 

Bacterial cellulose has several properties that have been identified as useful for PEM fuel cell development, including thermal stability and low hydrogen crossover characteristics. 

Bacterial cellulose has several unique properties that potentially make it a valuable material for the development of PEM fuel cells (Reference 1) (1) it is an inexpensive and non-toxic natural resource (2) it has good chemical and mechanical stability (3) it is very hydrophilic and (4) it doesn t re-swell after drying. Additionally, its thermal stability and gas crossover characteristics are superior to Nation 117 , a material currently widely used as a proton conductive membrane in PEM fuel cells. 

There is a wealth of data, both in the scientific and patent literature, on the chemical modification of plant cellulose. All of these methods are equally applicable to bacterial cellulose given that the two types of cellulose are chemically identical. However, it is the physical structure of bacterial cellulose membranes that make them a potential material for PEM fuel cells. Therefore, the aim is to modify bacterial cellulose pellicules in a manner that retains the structure of the cellulose and does not... 

Evans, B.R., O Neill, H., Malyvanh, V.P., Woodward, J. Palladium-bacterial cellulose membranes for fuel cells Biosensors and Bioelectronics, submitted... 

Major Applications Sol-gel matrix, fuel cells, optical sensors, combustion gas detection system, paints, toys, cleaning products, detergents, textiles, " food freshness sensor, iden-tilying fresh and stale rice, wheat, detecting microorganisms, bacterial growth, psychoactive drug, dental materials ... 

Major Appiications Fuel cell power generation system, liquid crystal displays, solor cells, sensors, thermochromic materials,coloring wood,n detergents, assessment of tobacco smoke, cosmetics,14 detect bacterial infections,i multidrug resistance inhibitors, treatment of bums, endodontic, diabetes, obesity, 5 cancer,2o age-related macular degeneration, viral diseases Safety/Toxicity Acute toxicity, combustion toxicity, 4 cytotoxicity, genotoxicity, mutagenicity, nephrotoxicity, phototoxicity, soil toxicity ... 

The operating conditions, which are easy to manage, make the application of biological processes for the desulfurization of middle distillates advantageous. The process involving the recovery of the bacterial solution does not require the addition of hydrogen or any other consumable. One factor impeding application in fuel cell APUs, however, is the insufficient activity of bacterial strains known to us today. The residence times required would result in unrealistic reactor dimensions. 

Aelterman P, Fregnia S, Keller J, Verstraete W, Rabaey K. The anode potential regulates bacterial activity in microbial fuel cells. Appl Microbiol Biotechnol 2008 78 409-418. 

Logan BE, Regan JM. Electricity-producing bacterial communities in microbial fuel cells. Trends Microbiol 2006 14 512-518. 

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