Plant-microbial fuel cell application in saline waters

The plant-microbial fuel cell (P-MFC) is a new technology for sustainable and in-situ production of electricity from living plants (Strik, 2008). The P-MFC makes use of electrochemically-active bacteria that catalyse the anaerobic oxidation of rhizodeposits at the roots of plants. By connecting the plant roots and bacteria directly to an electrical circuit, current will flow as a result of oxygen reduction at the other end of the circuit. This current can be harvested as electricity.

As of yet the highest power output per cubic meter by a P-MFC has been achieved in a salt marsh at high salinity (Wetser, 2015). This makes the plant-microbial fuel cell a saline water technology with the potential to convert salt marches or (constructed) wetlands into electricity producing sites. Plant vitality is not harmed and the technology can even be combined with biomass production (Schampelaire, 2008). And since most of the system is placed subsurface, the P-MFC will not alter landscape aesthetics. Furthermore, the application of plant/sediment-MFCs has proved to reduce methane emissions from anaerobic soils, a greenhouse gas twenty-four times more powerful than CO2 (Arends, 2014).

In order to improve the P-MFC, the role of salts in this system needs to be clarified through the characterization and quantification of ion-transport.