New microbial electrosynthesis system for methane production from carbon dioxide coupled with oxidation of sulfide to sulfate  

作　　者：Hiromi Kambara Ha T.T.Dinh Shuji Matsushita Yoshiteru Aoi Tomonori Kindaichi Noriatsu Ozaki Akiyoshi Ohashi 

机构地区：[1]Department of Civil and Environmental Engineering,Graduate School of Engineering,Hiroshima University,1–4–1,Kagamiyama,Higashi-Hiroshima,Hiroshima 739–8527,Japan [2]Faculty of Environment,Ho Chi Minh City University of Natural Resources and Environment,236 Le Van Sy,1 Ward,Tan Binh District,Ho Chi Minh City,Vietnam [3]Agricultural Technology Research Center,Hiroshima Prefectural Technology Research Institute,6869,Hara,Hachihonmatsu,Higashihiroshima,Hiroshima 739–0151,Japan [4]Program of Biotechnology,Graduate School of Integrated Sciences for Life,Hiroshima University,1–3–1,Kagamiyama,Higashi-Hiroshima,Hiroshima 739–8530,Japan [5]Department of Civil and Environmental Engineering,Graduate School of Advanced Science and Engineering,Hiroshima University,1–4–1,Kagamiyama,Higashi-Hiroshima,Hiroshima 739–8527,Japan

出　　处：《Journal of Environmental Sciences》2023年第3期786-797,共12页环境科学学报（英文版）

基　　金：supported by the Japan Society for the Promotion of Science (JSPS) through a Grant-in-Aid for Scientific Research (No. 17H01300)。

摘　　要：Microbial electrosynthesis system (MES) is a promising method that can use carbon dioxide,which is a greenhouse gas,to produce methane which acts as an energy source,without using organic substances.However,this bioelectrical reduction reaction can proceed at a certain high applied voltage when coupled with water oxidation in the anode coated with metallic catalyst.When coupled with the oxidation of HS–to SO_(4)^(2-),methane production is thermodynamically more feasible,thus implying its production at a considerably lower applied voltage.In this study,we demonstrated the possibility of electrotrophic methane production coupled with HS–oxidation in a cost-effective bioanode chamber in the MES without organic substrates at a low applied voltage of 0.2 V.In addition,microbial community analyses of biomass enriched in the bioanode and biocathode were used to reveal the most probable pathway for methane production from HS–oxidation.In the bioanode,electroautotrophic SO_(4)^(2-)production accompanied with electron donation to the electrode is performed mainly by the following two steps:first,incomplete sulfide oxidation to sulfur cycle intermediates (SCI) is performed;then the produced SCI are disproportionated to HS^(–)and SO_(4)^(2-).In the biocathode,methane is produced mainly via H_(2)and acetate by electronaccepting syntrophic bacteria,homoacetogens,and acetoclastic archaea.Here,a new ecofriendly MES with biological H_(2)S removal is established.

关 键 词：Microbial electrosynthesis system Low applied voltage Organic substrates Methane production Sulfur oxidation 

分 类 号：X701[环境科学与工程—环境工程]