Accelerating electricity power generation and shortening incubation period of microbial fuel cell operated in tidal flat sediment by artificial surfactant anode modification

Abstract

Microbial fuel cell (MFC) performance improves with the addition of synthetic surfactants and biosurfactants in its medium. However, the excessive presence of surfactants, especially synthetic surfactants, leads to inhibited MFC performance. This study is the first investigation for the performance of an MFC operating in real tidal flat sediment when its anode was modified with synthetic surfactants and biosurfactants. The output power intensity of the MFC was inhibited by anodic modification using sodium cholate (SC) as a biosurfactant. This inhibition was also observed at higher and lower SC concentrations. In contrast, anodic modification using polysorbate 20 accelerated the output power intensity of the MFC. The optimal polysorbate 20 concentration was determined to be 25–50 wt%. Under the optimized anode-modified conditions, a rapid increase in the output intensity was observed 7–10 days after the operation. At the most optimal polysorbate 20 concentration (50 wt%), the exchange current density was estimated to be 405 mA m−2, which was more than ten times higher than that (33 mA m−2) obtained at the unmodified anode. This result was due to increasing an electron transfer reaction rate. In conclusion, this positive effect was caused by the synergistic effects of accelerated microorganism proliferation and electron transfer rates at the anode interface.