矩形微生物燃料电池阳极室传质模拟

Modeling on mass transport in anode chamber of rectangular microbial fuel cell

以碳布为阳极材料、无添加电子介体微生物燃料电池的阳极室为模拟对象,建立了底物在阳极室和生物膜内传质过程以及生物膜内生化与电化学反应的控制方程,考察了阳极电势和进口底物流量对底物浓度分布、降解效率及电流密度的影响。计算结果表明,阳极电势对阳极室及生物膜内底物浓度的分布有着重要的影响。阳极电势越高,阳极室及生物膜内底物浓度越低,底物降解效率越高,产生的电流密度越大。进口底物流量越大,底物在反应器中水力停留时间越短,底物降解效率越低;随着进口底物流量的增加,单位时间内底物的传质通量增大,生物膜内底物的消耗速率增加,因此电流密度随之增大。

The two-dimension modeling study on the mass transport in the anode chamber of rectangular microbial fuel cell without added mediator with carbon cloth as anode was performed. The effects of the anode potentials and substrate inlet flux on the substrate concentrations distribution in the biofilm and anode chamber, substrate removal efficiency and current densities were researched. The results by modeling were agreed well with the experimental results. And the modeling results show that the anode potentials play an important role in the distribution of substrate concentrations in the biofilm and anode chamber. With higher anode potential, the substrate concentration was lower and the substrate removal efficiency and current density were larger. The larger inlet substrate flux, the hydraulic retention time was less, also the substrate degradation efficiency was less. And with the increase of inlet substrate flux, the mass transfer flux of substrate per unit of time and substrate consumption rate increased, so the current density was higher.