Shanghai Municipal Engineering Design Institute (Group) Co., Ltd, Shanghai, 200092, China.
Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200241, China.
Chemosphere. 2024 Jun;358:142119. doi: 10.1016/j.chemosphere.2024.142119. Epub 2024 Apr 30.
The CO 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 CO 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 CO 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 CO bioelectromethanosynthesis, and renewable energy storage.
通过双室微生物电解池（MEC）进行 CO 生物电甲烷合成具有巨大的潜力，可以解决能源危机并减少温室气体排放。然而，由于膜内质子扩散差和内阻高，膜污染仍然是 CO 生物电甲烷合成的一大挑战。在这项研究中，在阴极室中设计了一种带有沼气再循环单元的新型 MEC 生物反应器，以增强 CO2 的二次溶解，同时减轻污染物在膜表面的附着。沼气再循环提高了 CO 的再溶解，降低了浓度极化，并促进了质子的跨膜扩散。这使得阴极甲烷的产率从 0.4 mL/L·d 显著增加到 8.5 mL/L·d。阳极有机降解细菌（Firmicutes 5.29%，Bacteroidetes 25.90%和 Proteobacteria 6.08%）和阴极甲烷产生古菌（Methanobacterium 65.58%）之间存在牢固的共营养关系，能够同时进行有机降解、高效 CO 生物电甲烷合成和可再生能源存储。
