底物浓度影响微生物燃料电池性能和生物生长的模拟研究

建立了含有悬浮微生物、电极上生物量、可溶性化学底物和中介体的微生物燃料电池(MFC)数学模型。通过底物降解、生物增长和电流产生过程的模拟,考察了生物量和底物随时间的变化规律,底物质量浓度对生物量、底物降解和电流的影响。结果表明,当溶液中初始微生物量很少时,随着MFC反应的进行,生物主要富集在电极上,溶液中生物生长缓慢;MFC中的生物生长经历延滞期、对数期和平稳期,底物分解经历缓慢、快速和消耗殆尽3个阶段。底物质量浓度小于等于250 mg/L时,生物延滞期时间、底物缓慢分解阶段时间、生物生长到达平稳时间、底物消耗殆尽的时间和电流到达最大值所需的时间随着底物质量浓度的增加而缩短。底物质量浓度大于250 mg/L时,生物延滞期时间、底物缓慢分解阶段时间、生物生长到达平稳时间、底物消耗殆尽的时间和电流到达最大值所需的时间随着底物质量浓度的增加而增加。

Simulation study on effect of substrate concentration on performance of MFC and biomass growth

Microbial fuel cell (MFC) mathematical model was established with suspended microorganisms, biomass on the electrode material, soluble chemical substrates and intermediary. By simulating the degradation process of the substrate, biomass growth and the electric current production process, the change of microbial biomass and substrate concentration with time, the impact of substrate concentration on biomass, substrate degradation process and electric current generation were investigated. The results showed that when the original microbial biomass is rarely in the solution, microorganisms mainly enriched in the electrode and grew slowly in solution with the MFC operation. Microorganisms growth experienced three phases: delaying period, logarithmic phase and stable period, and the decomposition of substrate needed to undergo three corresponding stages: slow, fast and depleted. When the substrate concentration was greater than 250 mg/L,the time of the microbial delaying, the slow stage time of substrate decomposing, the time of microbial growth to reach a steady period and the substrate end to deplete, the time of the electric current to reach the maximum, all increased with the increase of substrate concentration.