Microbial fuel cell new

Amicrobial fuel cell(MFC) orbiological fuel cellis a bio- electrochemicalsystem that drives a currentby usingbacteria and mimicki ... bacteriaand mimicking bacterial interactions found in nature. MFCs can be grouped into two general categories, those that use a mediator and those that are mediator-less. The first MFCs, demonstrated in the early 20th century, used a mediator: a chemical that transfers electrons from the bacteria in the cell to the anode. Mediator-less MFCs are a more recent development dating to the 1970s; in this type of MFC the bacteria typically have electrochemically active redox proteinssuch as cytochromeson their outer membrane that can transfer electrons directly to the anode. [ 1 ]Since the turn of the 21st century MFCs have started to find a commercial use in the treatment of wastewater. [ 2 ] History The idea of using microbial cells in an attempt to produce electricitywas first conceived in the early twentieth century. M. Potter was the first to perform work on the subject in 1911. [ 3 ]A professor of botany at the University of Durham, Potter managed to generate electricity from E. coli, but the work was not to receive any major coverage. In 1931, however, Barnet Cohen drew more attention to the area when he created a number of microbial half fuel cells that, when connected in series, were capable of producing over 35 volts, though only with a current of 2 milliamps. [ 4 ] More work on the subject came with a study by DelDuca et al. who used hydrogen produced by the fermentationof glucose by Clostridium butyricumas the reactant at the anode of a hydrogen and air fuel cell. Though the cell functioned, it was found to be unreliable owing to the unstable nature of hydrogen production by the micro-organisms. [ 5 ]Although this issue was later resolved in work by Suzuki et al. in 1976 [ 6 ]the current design concept of an MFC came into existence a year later with work once again by Suzuki. [ 7 ] By the time of Suzuki’s work in the late 1970s, little was understood about how microbial fuel cells functioned; however, the idea was picked up and studied later in more detail first by MJ Allen and then later by H. Peter Bennetto both from King's College London. People saw the fuel cell as a possible method for the generation of electricity for developing countries. His work, starting in the early 1980s, helped build an understanding of how fuel cells operate, and until his retirement, he was seen by many[ who?]as the foremost authority on the subject. It is now known that electricity can be produced directly from the degradation of organic matter in a microbial fuel cell. Like a normal fuel cell, an MFC has both an anode and a cathode chamber. The anoxicanode chamber is connected internally to the cathode chamber via an ion exchange membrane with the circuit completed by an external wire. In May 2007, the University of Queensland, Australia completed its prototype MFC as a cooperative effort with Foster's Brewing. The prototype, a 10 L design, converts brewery wastewaterinto carbon dioxide, clean water, and electricity. With the prototype proven successful[ citation needed], plans are in effect to produce a 660 gallon version for the brewery, which is estimated to produce 2 kilowatts of power. While this is a small amount of power, the production of clean water is of utmost importance to Australia, for which droughtis a constant threat.