微生物电合成系统还原二氧化碳产甲烷的电势依赖性  

Influence of cathodic potential on methane production from CO_2 in a microbial electrosynthesis system

作　　者：鲍白翎 杨厚云 苏馈足[1] 穆杨[2] 

机构地区：[1]合肥工业大学土木与水利工程学院,合肥230009 [2]中国科学技术大学化学与材料科学学院,合肥230026

出　　处：《应用与环境生物学报》2017年第6期968-973,共6页Chinese Journal of Applied and Environmental Biology

基　　金：国家自然科学基金项目(51478446)资助~~

摘　　要：二氧化碳(CO_2)资源化利用是近年来的一个研究热点,利用生物电化学系统还原CO_2生产能源物质是一种新兴技术.在微生物电合成系统(MES)中利用混合微生物富集阴极功能微生物,评估阴极电势对其还原CO_2产甲烷的影响.当阴极电势从-0.70 V降低到-0.90 V vs Ag/Ag Cl时,MES产甲烷的量和速率都在增加,最大的产甲烷量和速率分别达到了0.265 mol/m^2和0.025 mmol/h.与此同时,MES的电流密度从0.002 A/m^2增加到0.18 A/m^2,阴极产甲烷的库伦效率在49%和90%之间.当阴极电势更负时,MES阴极几乎不产甲烷.扫描电镜分析(SEM)表明,有多种不同形态的微生物吸附在阴极碳毡上,它们的形态主要呈杆状和球状.16S r DNA测序分析表明Methanobacterium是MES阴极生物膜上优势的产甲烷菌.本研究表明,微生物电合成系统还原CO_2产甲烷的阴极电势必须控制在适当的范围内,才能高效地还原CO_2产甲烷.Carbon dioxide utilization has been an important research topic in recent years. The use of bioelectrochemical systems capable of reducing CO2 to produce energy is an emerging technology. This study evaluated the effect of cathodic potential on methane production from CO2 in microbial electrosynthesis systems （MESs） with a mixed-culture biocathode. As the cathodic potential was decreased from ？0.70 V to ？0.90 V vs. Ag/AgCl, the yield and rate of methane production increased; the maximum amount and highest rate of methane production in MESs reached up to 0.265 mol/m2 and 0.025 mmol/h, respectively. The current density of the MES increased markedly, from 0.002 A/m2 to 0.18 A/m2, while the coulombic efficiency of methane production in the cathode increased from 49% to 90%. When the cathodic potential was more negative, the cathode of the MES produced negligible amounts of methane. Scanning electron microscope （SEM） confirmed that a variety of microorganisms were attached to the cathode carbon felt, and the morphologies of these microorganisms were mainly in the shapes of rods and spheres. 16S rDNA sequencing analysis revealed that Methanobacterium was the predominant methanogen in the biofilm on the cathode of the MES. These results suggest that the cathodic potential in MESs must be controlled within an appropriate range, to efficiently produce methane from CO2.

关 键 词：微生物电合成系统(MES) 二氧化碳 甲烷 阴极电势 Methanobacterium 

分 类 号：X172[环境科学与工程—环境科学] X701