Basic electricity-producing characteristics of microbial fuel cell using supernatant fluid of heat pretreated sludge

Using a single-chamber air cathode microbial fuel cell (MFC) as experimental reactor, its electricity generation using sludge supernatant fluid with heat pretreatment was studied. The results showed that its maximum power density (P_max) of MFC was highest (44.4 mW/m²), when it was heated for 3 h at 90°C, which was 105 times that of MFC without heat pretreatment. Absorbance of UV₂₅₄ and A₂₅₀/A₃₆₅ manifested that the substrate composition of supernatant fluid was most conducive to anodic microbial metabolism in electricity. P_max of MFC was only 5.8 mW/m², when MFC used the sludge heat pretreated again as substrate. These results evidently demonstrated the advantages of heating pretreatment to sludge for enhancing MFC power and combing with existing process easily, it was close to actual application.