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

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.