Abstract
Bioelectrochemical conversion of CO2 to CH4 is a promising way to increase the calorific value of biogas produced during anaerobic digestion. There are two groups of methanogens enriched in these systems, hydrogenotrophs and acetoclastic methanogens that can also directly accept electrons from an electrode or another microorganism. In this study, a microbial electrolysis cell (MEC) poised at -500 mV (vs. SHE) was operated for biogas upgrading. Methane content in the biogas increased from 71% to >90%, and 8.2% of the CO2 was converted to methane. Methanothrix, an acetoclastic methanogen that can participate in direct electron transfer (DET), and Azonexus, an acetate-oxidizing electrogen, were enriched on the cathode. Transcriptomics revealed that Methanothrix on the cathode were using the CO2 reduction pathway, while Methanothrix in the bulk sludge were using the acetate decarboxylation pathway for production of methane. These results show that stimulation of DET in MEC enhances biogas-upgrading processes.
Citations
May 13, 2020·Brazilian Journal of Microbiology : [publication of the Brazilian Society for Microbiology]·Adriana GiongoRenata Medina-Silva
Apr 25, 2020·Water Environment Research : a Research Publication of the Water Environment Federation·Qi HuangBipro Ranjan Dhar
Nov 28, 2020·Journal of Environmental Management·Shaoyuan BaiYanhong Li
Jan 10, 2021·Bioresource Technology·Chao LiuMukesh Kumar Awasthi
Nov 23, 2019·Bioresource Technology·Hanbing NieDawn E Holmes
Nov 27, 2019·Bioresource Technology·Xinying LiuDawn E Holmes
Jan 11, 2021·The Science of the Total Environment·Renxin ZhaoBing Li
Sep 13, 2020·Trends in Biotechnology·Shanfei FuYifeng Zhang
Mar 18, 2021·PloS One·Árpád SzilágyiGábor Rákhely
Mar 19, 2021·Bioresource Technology·Jiewen XiaoYan Dang
Apr 1, 2021·Water Research·Chuanqi LiuDawn E Holmes
Oct 9, 2020·Bioresource Technology·Fengbo WangMiaomiao Du
Apr 14, 2021·Bioresource Technology·Sijie HuangZhidan Liu
Apr 21, 2021·Bioresource Technology·Hanbing NieDawn E Holmes
Aug 2, 2021·Bioresource Technology·Xiaojing ZhangHongzhong Zhang
Aug 20, 2021·Water Research·Jie ChengYan He