微生物および生化学技術ジャーナル

概要

Deterioration in the Cathode Performance during Operation of the Microbial Fuel Cells and the Restoration of the Performance by the Immersion Treatment

Osamu Ichihashi and Kayako Hirooka

Microbial fuel cells were operated with synthetic wastewater containing phosphate as a buffer and sodium acetate as a substrate. Linear sweep voltammetry showed the deterioration in the performance of the cathodes after operation. The immersion of the deteriorated cathodes in Milli-Q water, acidic and basic buffer solutions improved the performance. The treatment in the acidic buffer solution restored the performance of the cathode to the extent almost equivalent to that of a new cathode, whereas the treatment in Milli-Q water and the basic buffer solution did not restore the performance to that extent. The improved performance by the immersion in Milli-Q water or the buffer solutions indicates that the water-soluble components are responsible for the deterioration in the cathode performance. Almost complete recovery of the performance in acidic condition suggests that salts that are highly soluble in acidic condition, and poorly soluble in basic condition are responsible for the deterioration. The analysis of the eluted substances in the immersion solution suggests that these salts contained phosphorus, magnesium and calcium in a high concentration.