What is a microbial fuel cell?
Microbial fuel cells harness the power of bacteria and convert energy released in metabolic reactions into electrical energy. The actual cell consists of two electrodes separated by a semi-permeable membrane submersed in an electrolyte solution.
How Does a Microbial Fuel Cell Work?
In the anaerobic chamber, a solution containing food for the bacteria is circulated. This food consists of glucose or acetate, compounds commonly found in food waste and sewage. The bacteria metabolize food by first breaking apart the food molecules into hydrogen ions, carbon dioxide, and electrons. As shown in Fig. 3, bacteria use the electrons to produce energy by way of the electron transport chain. The microbial fuel cell disrupts the electron transport chain using a mediator molecule to shuttle electrons to the anode. In many ways, a microbial fuel cell is an extension of the electron transport chain where the final step of the process (the combination of oxygen, electrons, and H+ to form water) is transferred outside of the bacterial cell from which energy can be harvested.
A Brief History of the Microbial Fuel Cell
Ways the MFC can improve the world
Brewery Wastewater Treatment
Sewage wastewater can also be converted via microbial fuel cells to decompose the waste organic material contained within it. Research has shown that MFCs can reduce the amount of organic material present in sewage wastewater up to 80% . The process is very similar to brewery wastewater treatment, with the difference being that the water must first be pretreated to remove toxins and other non-biodegradable materials. This is a challenging step because sewage wastewater often varies in composition and may require extensive treatment before it can be cleaned by the MFC. However, this extensive treatment is justified by the electricity produced while cleaning the wastewater. The electricity production from MFCs will help to offset the high costs of processing wastewater . Wastewater treatment plants could end up dumping fewer pollutants into oceans and rivers if the money saved from the electricity bill is put to work further cleansing the wastewater.
Remote Power Source
Microbial fuel cells have become an interesting and promising area of research. The many applications of MFCs will help to reduce the use of fossil fuels and allow for energy gain from wastes. MFC technology does not have the power to change the world single-handedly; microbial fuel cells will never be able to produce enough electricity to take the place of a coal-fired power plant. They will, however, help to bring the world to becoming a sustainable and more environmentally-friendly place.
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