Marine photosynthetic microbial fuel cell for circular renewable power production

Abstract

Abstract Marine photosynthetic Microbial fuel cells (mpMFCs) can utilize marine photosynthetic microorganisms to drive electrical energy generating electrochemical reactions. Due to improved ionic mobility and superior electrical conductivity of sea water, it is a suitable electrolyte for operating bio-electrochemical devices at operating elevated salinities. This study examined the use of seawater as a conducting medium in two-chambered MFCs to enhance power production in conjunction with a marine photosynthetic bio-cathode as an alternative to the abiotic chemical cathode. Using a modified BG11 seawater medium as catholyte, marine cyanobacteria were grown and maintained in the MFC cathode compartment. After a significant quantity of biomass had formed, it was harvested for use as the substrate for anode microorganisms. Isolated marine cyanobacteria from photosynthetic biocathode were identified using 16s rRNA and Sanger DNA sequencing. In electrochemical characterization, mMFC, maximum power density (Pmax) was 147.84 mW/m2 and maximum current density (Jmax) reached 1311.82 mA/m2. In mpMFC, Pmax was 104.48 mW/m2 and Jmax was 1107.27 mA/m2. Pmax was 53.14 mW/m2 and Jmax was 501.81 mA/m2 in comparable freshwater MFC employing platinum catalyst, which proves that mMFC & mpMFC worked better. Dapis pleousa & Synechococcus moorigangaii were identified as dominant marine cyanobacteria. It was demonstrated that mpMFC, operated using seawater, employing a cyanobacteria biocathode, is suitable for circularized renewable energy production. The outcomes of this study implies that, mpMFCs are good candidates for circular renewable energy production.