A phosphorus-free anolyte to enhance coulombic efficiency of microbial fuel cells

In this study, a phosphorus-free anolyte is prepared by using bicarbonate to replace phosphate buffer for application in two chamber microbial fuel cells (MFCs). Optical density test and Bradford protein assay shows that this phosphorus-free anolyte effectively inhibits the growth and reproduction of microorganisms suspended in the solution and greatly reduces the suspended cell mass. As a result, it considerably enhances the coulombic efficiency (CE) of MFCs. When the acetate concentration is 11 mM, the CE of the MFC using the pH 7 phosphate-containing anolyte is 9.7% and the CE with the pH 8.3 phosphate-containing anolyte is 9.1%, while the CE of the MFC using the phosphorus-free anolyte (pH 8.3) achieves 26.6%. This study demonstrates that this phosphorus-free anolyte holds the potential to enhance the feasibility for practical applications of MFCs. [Display omitted] A phosphorus-free anolyte effectively inhibits the growth and reproduction of microorganisms suspended in the solution, greatly reduces the suspended cell mass and considerably enhances the coulombic efficiency of MFCs. •The phosphorus-free anolyte inhibits the growth and reproduction of suspended cells.•The phosphorus-free anolyte greatly reduces the suspended cell mass.•The phosphorus-free anolyte enhances the coulombic efficiency of MFCs.