As urban populations grow and our climates change, alternative technologies are becoming increasingly important potential solutions for carbon management. Bacterial (aka microbial) fuel cells (MFCs) are one such technology that holds great promise. Researchers at USC have helped lead the way in this field, examining how to harness the metabolism of bacteria to facilitate more efficient breakdown of organic waste while also generating clean electricity.
Bacteria are important decomposers in many ecosystems; they are widely distributed and break down just about any type of organic matter. This can include food waste, environmental pollutants and industrial or human wastewater - traditional urban and industrial byproducts that are costly to treat or remove. By coupling microbial cells to waste plants, USC researchers have shown that bacteria can digest these organic materials to create cleaner and faster end products. In some cases “sludge” can be converted into gray-water or clean water in a matter of days, compared to traditional methods that take more than a month to achieve a dirtier product. Additionally, by processing their waste on-site, industrial facilities could save millions of dollars in waste-removal costs.
Best of all, MFCs actually produce small amounts of electrical power as an offshoot of the metabolic breakdown process. According to USC researchers, some treatment systems could be designed so that, rather than using electricity to process waste, energy can actually be generated from it. Perhaps even enough that the activity of waste treatment could supplement a facility’s power needs, giving new value to a previously burdensome process.
USC Wrigley researchers are currently testing the fundamentals of this research, and other approaches that exploit the abilities of bacteria. They have designed various pilot systems, each devised to use different types of waste products such as wastewater treatment in San Diego, food recycling in East Los Angeles, and industrial waste processing from commercial southern California beer breweries. In addition, they have adapted the MFC systems for use in the removal of chromium and selenium, two toxic metals of importance in California. The team plans to continue optimizing these exciting waste removal and bioremediation biotechnologies at the USC Wrigley Marine Science Center and in other real-world scenarios around the country.