Optimizing bioelectromethanosynthesis of CO2 and membrane fouling mitigation in MECs via in-situ biogas recirculation

Weijie Hu; Shaojuan Zheng; Jiayi Wang; Xueqin Lu; Yule Han; Juan Wang; Guangyin Zhen

doi:10.1016/j.chemosphere.2024.142119

Optimizing bioelectromethanosynthesis of CO₂ and membrane fouling mitigation in MECs via in-situ biogas recirculation

Chemosphere. 2024 Apr 30:358:142119. doi: 10.1016/j.chemosphere.2024.142119. Online ahead of print.

Authors

Weijie Hu¹, Shaojuan Zheng², Jiayi Wang², Xueqin Lu³, Yule Han², Juan Wang², Guangyin Zhen⁴

Affiliations

¹ Shanghai Municipal Engineering Design Institute (Group) Co., Ltd, Shanghai, 200092, China.
² Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200241, China.
³ Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200241, China; Institute of Eco-Chongming (IEC), 3663 N. Zhongshan Rd, Shanghai, 200062, China.
⁴ Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200241, China; The State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, 200092, Shanghai, China; Shanghai Institute of Pollution Control and Ecological Security, 1515 North Zhongshan Rd. (No. 2), Shanghai, 200092, China; Technology Innovation Center for Land Spatial Eco-restoration in Metropolitan Area, Ministry of Natural Resources, 3663 N. Zhongshan Road, Shanghai, 200062, China. Electronic address: gyzhen@des.ecnu.edu.cn.

PMID: 38697567
DOI: 10.1016/j.chemosphere.2024.142119

Abstract

The CO₂ bioelectromethanosynthesis via two-chamber microbial electrolysis cell (MEC) holds tremendous potential to solve the energy crisis and mitigate the greenhouse gas emissions. However, the membrane fouling is still a big challenge for CO₂ bioelectromethanosynthesis owing to the poor proton diffusion across membrane and high inter-resistance. In this study, a new MEC bioreactor with biogas recirculation unit was designed in the cathode chamber to enhance secondary-dissolution of CO2 while mitigating the contaminant adhesion on membrane surface. Biogas recirculation improved CO₂ re-dissolution, reduced concentration polarization, and facilitated the proton transmembrane diffusion. This resulted in a remarkable increase in the cathodic methane production rate from 0.4 mL/L·d to 8.5 mL/L·d. A robust syntrophic relationship between anodic organic-degrading bacteria (Firmicutes 5.29%, Bacteroidetes 25.90%, and Proteobacteria 6.08%) and cathodic methane-producing archaea (Methanobacterium 65.58%) enabled simultaneous organic degradation, high CO₂ bioelectromethanosynthesis, and renewable energy storage.

Keywords: Bioelectromethanosynthesis; Electroactive microbes; Extracellular electron transfer; Microbial electrolysis cell; e(−)/H(+) donor.