Enhanced methane production in an anaerobic digestion and microbial electrolysis cell coupled system with co-cultivation of Geobacter and Methanosarcina

• Published in: Journal of environmental sciences (China) Vol. 42; no. 4; pp. 210 - 214
• Main Authors: Yin, Qi, Zhu, Xiaoyu, Zhan, Guoqiang, Bo, Tao, Yang, Yanfei, Tao, Yong, He, Xiaohong, Li, Daping, Yan, Zhiying
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.04.2016
• Subjects: AD–MEC coupled system; Anaerobiosis; Bioelectric Energy Sources; Biological Oxygen Demand Analysis; Carbon Dioxide; Co-cultivation; Electrolysis; Geobacter; Geobacter - physiology; Methane - metabolism; Methane production; Methanosarcina; Methanosarcina - physiology; 共培养; 厌氧消化; 微生物; 煤层气; 生产过程; 甲烷产量; 电解池; 耦合系统; Methanosarcina; Geobacter; Co-cultivation; Methane production; AD–MEC coupled system
• ISSN: 1001-0742; 1878-7320
• DOI: 10.1016/j.jes.2015.07.006

The anaerobic digestion（AD）and microbial electrolysis cell（MEC）coupled system has been proved to be a promising process for biomethane production.In this paper,it was found that by co-cultivating Geobacter with Methanosarcina in an AD–MEC coupled system,methane yield was further increased by 24.1%,achieving to 360.2 m L/g-COD,which was comparable to the theoretical methane yield of an anaerobic digester.With the presence of Geobacter,the maximum chemical oxygen demand（COD）removal rate（216.8 mg COD/（L·hr））and current density（304.3 A/m3）were both increased by 1.3 and 1.8 fold compared to the previous study without Geobacter,resulting in overall energy efficiency reaching up to 74.6%.Community analysis demonstrated that Geobacter and Methanosarcina could coexist together in the biofilm,and the electrochemical activities of both were confirmed by cyclic voltammetry.Our study observed that the carbon dioxide content in total gas generated from the AD reactor with Geobacter was only half of that generated from the same reactor without Geobacter,suggesting that Methanosarcina may obtain the electron transferred from Geobacter for the reduction of carbon dioxide to methane.Taken together,Geobacter not only can improve the performance of the MEC system,but also can enhance methane production.