Due to the impacts of climate change, humans have become more aware of the negative impacts of fossil fuels and are searching for alternative sources of energy production. Benthic mud, containing decaying microorganisms, is one of these alternative energy sources that are not broadly considered. Microbial fuel cells take water, as well as an organic substrate (https://www.omicsonline.org/), to create energy. There are many different types of organic substrates; one of the types we have on the island is benthic mud. Benthic mud is mud containing many different species of bacteria and other types of microorganisms. These microorganisms are an essential part of aquatic ecosystems. What these microorganisms do is feed off of any decay. Doing so cleans the water source preventing severe pollution. Since benthic mud is full of bacteria it is a perfect source for microbial fuel cells. Microbial fuel cells use the bacteria to transform the energy stored inside the chemical bonds into electrical currents that can be used to power devices without giving off as much heat, or producing carbon dioxide (https://www.sciencedirect.com/).
Organic matter is composed of organic compounds that come from the remains of plants, animals, and other waste products. Organic matter can be metabolized in order to create energy, which is what I'm doing in my experiment (https://www.omicsonline.org/).
Metabolism is the process by which your body converts what you eat and drink into energy (https://www.mayoclinic.org). In this case we are talking about the metabolism of the substrate, an underlying substance or layer. Metabolism can be either aerobic or anaerobic. Aerobic metabolism uses oxygen to create energy, while anaerobic metabolism occurs in an environment lacking oxygen, but still creates energy. My experiment took an environment without oxygen (Anaerobic) and used an air pump to add air (Aerobic). The reason I added oxygen was to accelerate the results of my project. If I had not converted the anaerobic environment into an aerobic environment the experiment would have taken longer than a month.
Microbial fuel cells take bacteria and use them to transform the energy stored in the chemical bonds of the substrate (in this case benthic mud) into electrical currents. Sugars, fats, proteins, and other “bio available molecules” are taken by the bacteria, transferred through a metabolic pathway, and then used by the electrons as energy for the cells. In this process oxygen is the driving force because it is attracted to the electrons and accepts them well. Therefore, without oxygen you cannot transfer the electrons effectively. (https://www.altenergy.org/; http://www.umsl.edu/)
The microbial fuel cell contains an anode and cathode chamber. The anode and the cathode chambers are connected by a salt bridge. The salt bridge is an essential part of my experiment since it keeps the electrical charge flowing. Without it, the electrons that are being produced in the anode chamber would build up in the cathode chamber resulting in the reaction to stop running. (https://courses.lumenlearning.com/).
In my experiment the electrodes allowed me to measure the electrical potential, or the difference in voltage between the anode chamber and the cathode chamber. These chambers are known as the fuel cell electrodes and the salt bridge is the electrolyte. Fuel, such as benthic mud, is fed to the anode and oxygen is fed to the cathode. Measuring the difference in voltage (i.e. electrical potential) between these two electrodes provides the data necessary to calculate power (or energy) produced by the fuel cell (https://www.energy.gov/).