Abstract: Response of a microbial fuel cell under variable load conditions is of paramount importance when it is used for the application of wastewater treatment.In this study，four two-chamber MFCs were started up and evaluated under an external resistance of 50，100，400，1000 Ω，respectively.The results indicated that MFC-50 has the longest log phase for the development of the biofilm while a highest maximum power density can be obtained after start-up.It was also found that the voltages of MFC-100 and MFC-50 dropped and maintained a steady-state when a 50Ω resistance was connected into the electrical circuit，whereas the voltages of MFC-400 and MFC-1000 elevated slowly for ～2 d to the values similar to those of MFC-200 and MFC-50 after the initial abrupt drop under the same loading condition.After the stabilization of the MFCs，the maximum power densities of all the MFCs were comparable and reached 2000 mW·m-2.Further switching the external resistance from a small to large one，no noticeable change in performance can be found.

Key words: variable load, performance response, microbial fuel cells, proton transfer

摘要： 变工况运行时微生物燃料电池(MFC)的响应特性是揭示其运行规律的重要因素之一，对于指导MFC的实际应用有重要意义。分别针对以50、100、400和1000Ω启动的双室型MFC，以电池的电压响应和性能参数为评价指标，研究了MFC的启动特性和启动完成后MFC对负载变化的响应特性。结果表明，启动电阻越小电池启动越慢，但其最大功率密度越大。与MFC-50和MFC-100相比，MFC-1000和MFC-400对50Ω负载响应的时间较长，且其负载电压均表现出先急剧下降后缓慢上升的特征。经过较长时间的适应期后，所有电池的最大功率密度均可达到2000 mW·m-2以上。此后，当上述MFC的负载切换为原培养电阻时，其响应时间明显缩短且电池最高功率密度不再发生变化。

关键词: 变负载, 性能响应, 微生物燃料电池, 质子传输