Optimizing the plant microbial fuel cell: diversifying applications and product outputs

A Microbial Fuel Cell (MFC) is a technology which enables the production of electrical current and power by bacteria from the breakdown of organic matter. This system can be applied in waterlogged soils and sediments but here organic carbon supply is limited. Adding a plant to the soil or sediment enables a continuous supply of organic matter in the soil due the photosynthesis and rhizodeposition processes of the plant. In this work, different components and designs of the plant-MFC were investigated in order to optimize electrical power output, find new niches for application or new products other than electrical power. In a first instance the optimal distribution of anode material in the soil was determined. These results were used for the second project which was aimed at studying the influence of a plant-MFC on greenhouse gas emissions from waterlogged environments. A third line of work entailed the concentration of soluble organic material from wastewater by means of a constructed wetland. The effluent of the wetland was used in a MFC to produce an electrical current. The electrical current was not used as electrical power, instead hydrogen peroxide was produced in the cathode for disinfection of the wetland effluent. A fourth line focused entirely on the cathode, where process operation and electrode design was studied for CO2 fixation to acetate by means of a pure culture of Acetobacterium woodii