Picioreanu Cristian, Head Ian M, Katuri Krishna P, van Loosdrecht Mark C M, Scott Keith
Department of Biotechnology, Faculty of Applied Sciences, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands.
Water Res. 2007 Jul;41(13):2921-40. doi: 10.1016/j.watres.2007.04.009. Epub 2007 May 29.
This study describes and evaluates a computational model for microbial fuel cells (MFCs) based on redox mediators with several populations of suspended and attached biofilm microorganisms, and multiple dissolved chemical species. A number of biological, chemical and electrochemical reactions can occur in the bulk liquid, in the biofilm and at the electrode surface. The evolution in time of important MFC parameters (current, charge, voltage and power production, consumption of substrates, suspended and attached biomass growth) has been simulated under several operational conditions. Model calculations evaluated the effect of different substrate utilization yields, standard potential of the redox mediator, ratio of suspended to biofilm cells, initial substrate and mediator concentrations, mediator diffusivity, mass transfer boundary layer, external load resistance, endogenous metabolism, repeated substrate additions and competition between different microbial groups in the biofilm. Two- and three-dimensional model simulations revealed the heterogeneous current distribution over the planar anode surface for younger and patchy biofilms, but becoming uniform in older and more homogeneous biofilms. For uniformly flat biofilms one-dimensional models should give sufficiently accurate descriptions of produced currents. Voltage- and power-current characteristics can also be calculated at different moments in time to evaluate the limiting regime in which the MFC operates. Finally, the model predictions are tested with previously reported experimental data obtained in a batch MFC with a Geobacter biofilm fed with acetate. The potential of the general modeling framework presented here is in the understanding and design of more complex cases of wastewater-fed microbial fuel cells.
本研究描述并评估了一种基于氧化还原介质的微生物燃料电池（MFC）计算模型，该模型包含多个悬浮和附着生物膜微生物种群以及多种溶解化学物质。大量的生物、化学和电化学反应可在主体液体、生物膜及电极表面发生。在多种运行条件下，模拟了MFC重要参数（电流、电荷、电压和功率产生、底物消耗、悬浮和附着生物量增长）随时间的变化。模型计算评估了不同底物利用产率、氧化还原介质标准电位、悬浮细胞与生物膜细胞比例、初始底物和介质浓度、介质扩散率、传质边界层、外部负载电阻、内源代谢、重复添加底物以及生物膜中不同微生物群体之间竞争的影响。二维和三维模型模拟显示，对于较年轻且分布不均的生物膜，平面阳极表面电流分布不均，但在较老且更均匀的生物膜中电流分布变得均匀。对于均匀平坦的生物膜，一维模型应能对产生的电流给出足够准确的描述。还可在不同时刻计算电压-电流和功率-电流特性，以评估MFC运行的极限状态。最后，用先前报道的在以醋酸盐为食的地杆菌生物膜的间歇式MFC中获得的实验数据对模型预测进行了测试。本文提出的通用建模框架的潜力在于理解和设计更复杂的废水喂养微生物燃料电池案例。
