Renewable and clean forms of energy are one of society’s greatest needs. At the same time, 2 billion people in the world lack adequate sanitation and the economic means to afford it. In this research, we are working to address both of these human needs. Energy costs are an important factor in wastewater treatment. In the USA, for example, 5% of electricity we produce is used for the water and wastewater infrastructure (all aspects, including pumping, treatment, etc.), with 1.5% used for wastewater treatment alone.
Microbial fuel cells (MFCs) represent a completely new method of renewable energy recovery: the direct conversion of organic matter to electricity using bacteria. While this sounds more like science fiction than science, it has been known for many years that bacteria could be used to generate electricity. However, expensive and toxic chemicals were needed to shuttle electrons from the bacteria to the electrode and purified chemicals (such as glucose) were needed for the bacteria to grow on. We now know that we can make electricity using any biodegradable material– even wastewater– and that we don’t have to add any special chemicals if we use bacteria already present in the wastewater. While some iron-reducing bacteria, such as Shewanella putrefacians and Geobacter metallireducens [they reduce Fe(III) to Fe(II)], can be used to make electricity. There are many other bacteria already present in wastewater that can make electricity, but generally bacteria belonging to the genus Geobacter are the ones that can produce the highest power densities.
This website contains a number of sections to introduce MFCs and other microbial electrochemical technologies (METs). For example, to see slide shows and videos, go to our Presentations page; to learn how to make anodes, cathodes or prepare media for laboratory experiments, go to our Make One page. There area also other types of METs described on the Logan Lab MFC website, for example: there is a page on microbial electrolysis cells (MECs) that can be used to electrochemically produce hydrogen gas at the cathode from current generated by bacteria on the anode; and a page on other types of METs the that can be used to desalinate water, capture nutrients, or capture CO2
There are also links to other websites that may be of interest, for example, the International Society of Microbial Electrochemistry and Technologies (ISMET) site. ISMET is an organization created to link together researchers from around the world that are working on MFCs and other types of METs.
Links to Public Reports
This research has been covered by Penn State Press releases, and published in various media (see below). Click on those links for more general descriptions of our findings.