Evaluation on direct interspecies electron transfer in anaerobic sludge digestion of microbial electrolysis cell.
Increase of methanogenesis in methane-producing microbial electrolysis cells (MECs) is frequently believed as a result of cathodic reduction of CO2. Recent studies indicated that this electromethanogenesis only accounted for a little part of methane production during anaerobic sludge digestion. Instead, direct interspecies electron transfer (DIET) possibly plays an important role in methane production. In this study, anaerobic digestion of sludge were investigated in a single-chamber MEC reactor, a carbon-felt supplemented reactor and a common anaerobic reactor to evaluate the effects of DIET on the sludge digestion. The results showed that adding carbon felt into the reactor increased 12.9% of methane production and 17.2% of sludge reduction. Imposing a voltage on the carbon felt further improved the digestion. Current calculation showed that the cathodic reduction only contributed to 27.5% of increased methane production. Microbial analysis indicated that DIET played an important role in the anaerobic sludge digestion in the MEC.
Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China.
Zisheng
Z
Zhao
Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China. Electronic address: zhangyb@dlut.edu.cn.
Yaobin
Y
Zhang
Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China.
Xie
X
Quan
Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China.
Huimin
H
Zhao
D000693:Anaerobiosis; D019149:Bioreactors / Q000382:microbiology*; D004566:Electrodes; D004572:Electrolysis / Q000295:instrumentation*; D004583:Electrons; D008697:Methane / Q000378:metabolism; D012722:Sewage / Q000737:chemistry / Q000382:microbiology
D012722:Sewage; D008697:Methane
Anaerobic sludge digestion; Conductive materials; Direct interspecies electron transfer; Microbial electrolysis cells