For most of us, the word “micro-organism” takes us back to high school biology lab. At the time, few of us knew that the bacteria swimming under our microscopes were powerhouses that could be harnessed to create energy.
Microbial fuel cells function much like normal fuel cells, generating electricity by causing a chemical reaction between two electrodes. The difference is that they convert chemical energy to electrical energy through the catalytic reaction of microorganisms.
One day, they may be used to power everything from light bulbs to hydrogen-powered vehicles.
All fuel cells have two electrodes – a positive anode, and a negative cathode. They also have an electrolyte, which carries electrically charged particles from one electrode to the other, as well as a catalyst, which helps speed the reaction.
In microbial fuel cells, energy in the anode is fueled by the microbial decomposition of organic matter. Bacteria living in wastewater—an abundant byproduct of modern society—can be tapped into as a source of power.
“It can be used to convert any biodegradable organic matter directly to an electrical current,” says Penn State environmental engineer Bruce Logan. “That electrical current can be used to produce electric power like to light a light bulb or spin a fan. Or it can be used to treat wastewater; it can be used to recover organic matter from bio-fuel production and turn that into electrical power.”
Logan estimates microbial fuel cell systems could be a reality in a few years. The biggest hurdle is getting the cost of building the systems down.
Then bacteria-power could run entire wastewater treatment plants and still generate enough extra electricity to keep the lights on in neighboring towns.
Photo, taken on September 15, 2008 in La Salle, Illinois, US, using a Nikon Coolpix S550, courtesy of Pam Broviak via Flickr.
Web Extra
Bruce Logan, an environmental engineer at Penn State, says microbial fuel cell systems are still in the developmental stages of production because of costs…
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