Abstract:

A novel electrochemical system was formed by coupling nitrifying granular sludge with microbial fuel cells（MFC）. The effects of influent pH and carbon-nitrogen ratio on the simultaneous treatment of wastewater and power production performance of the system were investigated in a sequential batch operation. The results showed that the removal rate of pollutants and power production performance increased and then decreased with the increase of influent pH and carbon-nitrogen ratio. When the influent pH was 10 and the carbon-nitrogen ratio was 15， the treatment system was able to utilize the unique stratified structure of aerobic granular activated sludge with anaerobic environment inside and aerobic environment outside. Under the condition of sufficient carbon source， the denitrifying bacteria reduced NO₃ ^- to N₂， and the system achieved the highest removal rates of COD and ammonia nitrogen， 96.05% and 98.58%， respectively. NO₂ ^- and NO₃ ^- in the effluent were at low levels， which effectively realized the process of simultaneous nitrification and denitrification. The maximum output voltage and power density of the coupled system were 459 mV and 116.40 mW/m²， respectively， under which more organic substrates were metabolized by the electrogenic bacteria to generate electrons， which enhanced the Coulomb efficiency of the system. The scanning electron microscopy results showed that the microorganisms were able to form biofilms on the electrode surface under alkaline conditions， which promoted the extracellular electron transfer process between the microorganisms and the electrode， thus enhancing the overall electrical generation performance of the system. It can provide scientific guidance for exploring and advancing the coupled MFC-particulate sludge system to treat actual wastewater and simultaneous capacity.

Key words: carbon-nitrogen ratio, granular sludge, microbial fuel cell

摘要：

将硝化颗粒污泥与微生物燃料电池（MFC）进行耦合构成一种新型电化学系统。采用序批式运行方式，研究进水pH和碳氮比对该系统同步处理废水及产电性能的影响。结果表明，随着进水pH和碳氮比的升高，系统对污染物的去除率和产电性能呈先增大后减小的趋势。当进水pH为10、碳氮比为15时，处理系统能够利用好氧颗粒活性污泥的独特分层结构，内部为厌氧环境，外部为好氧环境，反硝化菌在碳源充足的条件下将NO₃ ^-还原为N₂，系统对COD和氨氮的去除率最高，分别为96.05%、98.58%，且出水中的NO₂ ^-和NO₃ ^-处于较低水平，有效实现了同步硝化反硝化的过程。该耦合系统的最大输出电压和功率密度分别为459 mV、116.40 mW/m²。在此条件下更多的有机底物被产电细菌代谢生成电子，提升了系统的库仑效率。扫描电镜结果表明，碱性条件下微生物能够完好附着在电极表面形成生物膜，促进了微生物与电极之间的胞外电子传递过程，从而提升系统的整体产电性能。该研究可为探索与推进MFC-颗粒污泥耦合系统处理实际废水及同步产能提供科学指导。

关键词: 碳氮比, 颗粒污泥, 微生物燃料电池

CLC Number: 

• X703