葡萄糖乙酸钠不同基质微生物燃料电池电化学性能对比研究

The Study on Comparison of Electrochemical Performance in Microbial Fuel Cell with Glucose and Sodium Acetate Acting as Substrates

本文通过接种生活污水处理厂的好氧污泥和厌氧污泥,撘建两个双室微生物燃料电池(MFC,Microbial Fuel Cell),分别以葡萄糖、乙酸钠作为基质,在0.0335 mol·L^(-1)基质浓度下研究不同基质微生物燃料电池的产电性能.研究表明,葡萄糖体系的阳极半电池阻抗为222Ω,乙酸钠体系为213.67Ω,说明两种不同的有机基质对电池内阻无明显影响.葡萄糖、乙酸钠体系的交换电流密度i^0分别为3.463、5.987 mA·m^(-2),COD去除率分别为50.6%、55.8%,库仑效率分别为42.1%、46.2%.葡萄糖为基质时最大输出功率密度为394.2 mW·m^(-2),相应的最大电流密度为1800 mA·m^(-2);乙酸钠为基质时最大输出功率密度为311.9 mW·m^(-2),相应的最大电流密度为1527.5 mA·m^(-2).葡萄糖代谢过程复杂,并不单一,且代谢不彻底,乙酸钠分子简单更容易代谢,因此乙酸钠的库仑效率及COD去除率均高于葡萄糖,由以上数据可以得出葡萄糖为基质的燃料电池产电性能较好.

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 l） for glucose and 213.67 fl 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.m2, 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% wiht 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.