Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, 500 Dongchuan Rd, Shanghai 200241, PR China.
Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, 500 Dongchuan Rd, Shanghai 200241, PR China; Shanghai Institute of Pollution Control and Ecological Security, 1515 North Zhongshan Rd. (No. 2), Shanghai 200092, PR China; Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, Shanghai 200241, PR China; Technology Innovation Center for Land Spatial Eco-restoration in Metropolitan Area, Ministry of Natural Resources, 3663N. Zhongshan Road, Shanghai, 200062, China.
Water Res. 2024 Jun 1;256:121557. doi: 10.1016/j.watres.2024.121557. Epub 2024 Mar 30.
Electrochemical anaerobic membrane bioreactor (EC-AnMBR) by integrating a composite anodic membrane (CAM), represents an effective method for promoting methanogenic performance and mitigating membrane fouling. However, the development and formation of electroactive biofilm on CAM, and the spatio-temporal distribution of key functional microorganisms, especially the degradation mechanism of organic pollutants in metabolic pathways were not well documented. In this work, two AnMBR systems (EC-AnMBR and traditional AnMBR) were constructed and operated to identify the role of CAM in metabolic pathway on biogas upgrading and mitigation of membrane fouling. The methane yield of EC-AnMBR at HRT of 20 days was 217.1 ± 25.6 mL-CH/g COD, about 32.1 % higher compared to the traditional AnMBR. The 16S rRNA analysis revealed that the EC-AnMBR significantly promoted the growth of hydrolysis bacteria (Lactobacillus and SJA-15) and methanogenic archaea (Methanosaeta and Methanobacterium). Metagenomic analysis revealed that the EC-AnMBR promotes the upregulation of functional genes involved in carbohydrate metabolism (gap and kor) and methane metabolism (mtr, mcr, and hdr), improving the degradation of soluble microbial products (SMPs)/extracellular polymeric substances (EPS) on the CAM and enhancing the methanogens activity on the cathode. Moreover, CAM biofilm exhibits heterogeneity in the degradation of organic pollutants along its vertical depth. The bacteria with high hydrolyzing ability accumulated in the upper part, driving the feedstock degradation for higher starch, sucrose and galactose metabolism. A three-dimensional mesh-like cake structure with larger pores was formed as a biofilter in the middle and lower part of CAM, where the electroactive Geobacter sulfurreducens had high capabilities to directly store and transfer electrons for the degradation of organic pollutants. This outcome will further contribute to the comprehension of the metabolic mechanisms of CAM module on membrane fouling control and organic solid waste treatment and disposal.
电化学厌氧膜生物反应器 (EC-AnMBR) 通过集成复合阳极膜 (CAM)，是一种促进产甲烷性能和缓解膜污染的有效方法。然而，CAM 上电活性生物膜的发展和形成，以及关键功能微生物的时空分布，特别是有机污染物在代谢途径中的降解机制，还没有得到很好的记录。在这项工作中，构建并运行了两个 AnMBR 系统（EC-AnMBR 和传统 AnMBR），以确定 CAM 在代谢途径中对沼气升级和缓解膜污染的作用。在 HRT 为 20 天时，EC-AnMBR 的甲烷产量为 217.1±25.6 mL-CH/g COD，比传统 AnMBR 高约 32.1%。16S rRNA 分析表明，EC-AnMBR 显著促进了水解细菌（乳杆菌和 SJA-15）和产甲烷古菌（产甲烷菌和甲烷杆菌）的生长。宏基因组分析表明，EC-AnMBR 促进了与碳水化合物代谢（gap 和 kor）和甲烷代谢（mtr、mcr 和 hdr）相关的功能基因的上调，改善了 CAM 上可溶性微生物产物（SMP）/胞外聚合物（EPS）的降解，增强了阴极上的产甲烷菌活性。此外，CAM 生物膜在其垂直深度上对有机污染物的降解表现出异质性。具有高水解能力的细菌在上部积累，推动了对更高淀粉、蔗糖和半乳糖代谢的基质降解。在 CAM 的中下部形成了一个具有较大孔的三维网状蛋糕结构，其中具有高能力的电活性脱硫弧菌可以直接储存和传递电子，用于有机污染物的降解。这一结果将进一步有助于理解 CAM 模块在膜污染控制和有机固体废物处理和处置方面的代谢机制。
