双阳极室甲烷微生物燃料电池同步脱氮除硫性能及微生物群落分析

Simultaneous nitrogen and sulfur removal performance and microbial community changes of dual-anode chamber methane microbial fuel cells

摘要:

【背景】甲烷厌氧氧化(anaerobic oxidation of methane, AOM)包含反硝化型甲烷厌氧氧化和硫酸盐还原型甲烷厌氧氧化。目前，人们向水体中排放过量的含氮及含硫污染物，引起了严重的环境污染和生态破坏。【目的】利用甲烷厌氧氧化微生物燃料电池(microbial fuel cell, MFC)研究同步脱氮除硫耦合反应机理及反应过程中微生物的多样性信息。【方法】构建了3个微生物燃料电池(N-S-MFC、N-MFC、S-MFC)，以甲烷作为唯一碳源，探究其同步脱氮除硫性能，并采用16S rRNA基因高通量测序技术对微生物群落结构进行分析。【结果】N-S-MFC中硝酸盐和硫酸盐的去除率分别为90.91%和18.46%。阳极室中微生物的相对丰度提高，与反硝化及硫酸盐还原菌相关的微生物大量富集，如门水平上拟杆菌门(Bacteroidota)、厚壁菌门(Firmicutes)和脱硫杆菌门(Desulfobacterota)，同时属水平上Methylobacterium_Methylorubrum、Methylocaldum、Methylomonas等常见的甲烷氧化菌增多。【结论】N-S-MFC促进了硝酸盐还原，而对硫酸盐还原几乎无影响，本研究为甲烷MFC在污水中同步脱氮除硫的应用提供理论依据。

Abstract:

[Background] Anaerobic oxidation of methane (AOM) includes denitrification- dependent anaerobic methane oxidation and sulfate reduction-dependent anaerobic methane oxidation. At present, the excessive discharge of nitrogen and sulfur pollutants into water causes serious environmental pollution and ecological damage. [Objective] We used the AOM-microbial fuel cell (MFC) to study the coupling reaction mechanism of simultaneous nitrogen and sulfur removal and the microbial diversity changes during the reaction. [Methods] We constructed three MFCs (N-S-MFC, N-MFC, and S-MFC) with methane as the sole carbon source to explore the simultaneous nitrogen and sulfur removal performance. The 16S rRNA gene high-throughput sequencing was employed to analyze the microbial community structure. [Results] The removal rates of nitrate and sulfate in N-S-MFC were 90.91% and 18.46%, respectively. The relative abundance of microorganisms in the anode chamber increased, and the microorganisms involved in denitrification and sulfate reduction were enriched. Specifically, the relative abundance of common methanotrophs including Bacteroidota, Firmicutes and Desulfobacterota at the phylum level and Methylobacterium_Methylorubrum, Methylocaldums and Methylomonas at the genus level was increased. [Conclusion] N-S-MFC promotes nitrate reduction while having little effect on sulfate reduction. This study provides a theoretical basis for the application of methane MFC in simultaneous nitrogen and sulfur removal from wastewater.