Microbial fuel cells convert chemical energy to electrical energy by the action of microorganisms. As such, they have been explored as a renewable source of power, ideal for remote areas where access to electricity is limited. While fundamental research in this field began in the late 1970s, little progress has been made in moving toward practical applications. Dr. Zuyi “Jacky” Huang, Villanova University Associate Professor of Chemical Engineering and Director of the Biological and Environmental Systems Engineering Laboratory, has made it his mission to scale up the use of MFCs, particularly sediment microbial fuel cells. The University’s campus wetlands are serving as his living laboratory.
“Our goal is to develop a MFC to power a sensor and remove pollutants from stormwater in the wetlands,” says Dr. Huang. Sophomore Chemical Engineering major Brendan Gorman worked with Dr. Huang’s team through a Villanova Undergraduate Research Fellowship. His research titled “Optimization of Wetland Microbial Fuel Cells (wMFC) Using Novel Electrodes” was presented at the 2017 Undergraduate Research Symposium. Brendan explains how the process works, “The anode is buried in sediment, which is rich in organic matter and exoelectrogenic microorganisms. The organic matter is oxidized by those organisms, sending electrons from the anode to the cathode, which lies in the water above the sediment.”
Step one of this multi-phase process involved determining whether, in fact, the wetlands would work as a source for the MFCs. Once Dr. Huang’s team established that the environment was conducive, they set about researching the wetlands’ various soil compositions, noting that different soils consist of different organisms and vary in their ability to generate power. Given the typically low power density production of MFCs, the third and current phase of the research is focused on counteracting that issue by designing electrodes that provide efficient performance at a reasonable cost. A number of variables will be adjusted in order to optimize the wMFC design. These include electrode materials and design, placement, and testing with source water instead of distilled water. Finally, the wMFC will be combined with a power management system (PMS) to accumulate energy for increased electrical output that can power sensors in remote areas.
Dr. Huang says, “By combining the MFC with a proper PMS, renewable and maintenance-free electricity can be generated to power wetland sensors for many environmental monitoring applications.” With a seed grant from the Villanova Center for the Advancement of Sustainability in Engineering, and the support of Civil and Environmental Engineering Professor Dr. Bridget Wadzuk and Engineering Entrepreneurship Director Edmond Dougherty, Dr. Huang’s group has successfully built the first generation of sediment microbial fuel cells at Villanova. Future research by Villanova Engineering PhD student Xianhua Li will employ a computational fluid dynamics approach to scale up the size of the fuel cell in order to optimize the design and operation of large-scale microbial fuel cells and generate even more electricity.