Scientists have been trying to replace energy sources such as coal, natural gas and fossil fuel as they are not only limited but also harmful to the environment. Despite of the fact that we have a lot of renewable energy sources from sunlight, wind, and tides, however they are all uncontrollable to a certain extent. Therefore it is important that we can think of some economical and efficient replacement. Fortunately, scientists have come up with the idea of generating electricity from wastewater using microbes.
This idea has been around for decades but not until recently a team of engineers led by Dr. Liu at Oregon State University has had a major breakthrough which made the production of energy high enough to be used on a commercial scale. Their microbial fuel cell can generate 10 to 50 times more energy per volume than other similar fuel cells as they made some improvements by reducing anode–cathode spacing, utilizing evolved microbes and adopting better separator materials.
A schematic view of double microbial fuel cell.
Energy Environ. Sci.,2012
”The fuel cell resembles a book,” Dr Liu said. This cell basically consists of two electrodes, one is a platinum-coated cathode and the other is microbe-covered anode. At the anode, bacteria break down organic material in the wastewater to produce CO2, protons and electrons. Then the electrons along with protons will flow through a wire to the cathode creating an electric current. Also, the platinum coating cathode reacts with air to produce water. From the process we get water, CO2 and energy as our end products. In short, this process gets rid of some unwanted material in the wastewater and generates energy along the way.
Right now, Dr. Liu aims to make this wastewater treatment process self-sustainable. As technology advances, Dr. Liu expects treating wastewater to be an energy producer rather than an energy cost.
Besides limited energy and natural renewable energy sources, scientist have started a new era of generating energy from our own wastes.
The following video is provided by an Israel company called EMEFCY which describes the process of how they generate electricity from the waste water. The approach is similar to Dr. Liu’s microbial fuel cell.
References
“Converting Waster Water into Electricity.”30 September 2012 <https://www.youtube.com/watch?v=HYAlsOmJ-8M>.
Fan, Y., Han, S., & Liu, H. (2012). Improved performance of CEA microbial fuel cells with increased reactor size. Energy&Environmental Science, 5(8), 8273-8280.
Li, Sophia. “In Fuel Cells, Some Hope for Urban Sanitation.” The New York Times. 23 September 2012 <http://green.blogs.nytimes.com/2012/08/16/in-fuel-cells-some-hope-for-urban-sanitation/?partner=rss&emc=rss>.
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