微生物燃料电池阳极生物膜传质模拟

Simulation of the Mass Transfer in Anodic Biofilm of a Microbial Fuel Cell

微生物燃料电池对阳极溶液中可溶性有机物的氧化降解是通过附着在电极上的生物膜进行的.本文建立了微生物燃料电池阳极生物膜一维数学模型,采用有限容积法对控制方程进行离散,对组分方程和电势方程进行耦合求解,研究了生物膜的孔隙率、液相主体浓度和电导率对产电性能的影响。计算结果表明孔隙的存在对生物膜的产能具有积极作用;底物主体浓度较低时,底物浓度是限制电子产生的主要因素,随着底物主体浓度的升高,电导率是限制微生物电子生成的主要因素,提高电导率可以改善生物膜上的电子产生速率.高电导率不仅降低了生物膜内电子传递的阻力,而且也间接地提高了靠近液相主体的生物膜区域的电子生成速率。

The oxidative of soluble organics in the anodic room of microbial fuel cell is happened on the biofilm adhered onto the electrode. A steady-state one-dimensional mathematical model is presented to simulate the mass transfer in the anodic biofilm of a microbial fuel cell. The mass and charge conservation equation are solved by the finite volume method, and the influence of various parameters on power generation is considered, include porosity, bulk substrate concentration and electrical conductivity. Results show that the porous nature is a positive factor in the process of generating energy; the substrate concentration is the major factor to limit the electronics production when the bulk substrate concentration is low, but electrical conductivity instead when the bulk substrate concentration step up to a high level; The higher electrical conductivity reduced electron transfer resistance in the biofilm and also improved the electron generation at the region of the biofilm near the bulk substrate.