关键词: 微生物燃料电池, 葡萄糖, 乙酸钠, 电化学性能

Abstract:

By inoculating aerobic sludge and anaerobic sludge from the sewage treatment plant, two sets of dual-chamber microbial fuel cells (MFCs) were built with either glucose or sodium acetate acting as a substrate. Accordingly, the electrochemical performances of MFCs were explored with the concentration of the substrates being 0.0335 mol•L^-1. The results of the comparative study in glucose system and sodium acetate system showed that the impedance values of anodic half cell were 222 Ω for glucose and 213.67 Ω for sodium acetate, implying no significant effect on the internal resistance in battery with the different substrates. The exchange current densities were 3.463 mA•m^-2 and 5.987 mA•m^-2, while the COD removal rates 50.6% and 55.8% for glucose and sodium acetate, respectively. Furthermore, the coulombic efficiencies reached 42.1% and 46.2% with the maximum output power density of 394.2 mW•m^-2 and 311.9 mW•m^-2 for glucose and sodium acetate, respectively. Since the process of glucose metabolism is more complicated with less complete metabolism as compared with the simpler sodium acetate molecules with more facilitated metabolism, the coulombic efficiency and COD removal rate in sodium acetate system were higher than those in glucose system, which led to better eletricity production capacity.

Key words: Microbial fuel cell, glucose, sodium acetate, electrochemical performance