电位调控定向富集反硝化生物膜及脱氮效能研究  

Directional Enrichment of Denitrification Biofilm and Nitrogen Removal Efficiency Based on Potential Control

作　　者：刘鑫燃 高文钰 唐美怡 彭永臻[1] 崔丹 LIU Xinran;GAO Wenyu;TANG Meiyi;PENG Yongzhen;CUI Dan(National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology,Faculty of Environment and Life,Beijing University of Technology,Beijing 100124,China)

机构地区：[1]北京工业大学环境与生命学部,城镇污水深度处理与资源化利用技术国家工程实验室,北京100124

出　　处：《北京工业大学学报》2024年第12期1477-1485,共9页Journal of Beijing University of Technology

基　　金：国家重点研发计划资助项目(2021YFC3200603)。

摘　　要：为了探究不同电位下生物电极的反硝化效能、氮素转化途径以及相应的微生物菌群功能,构建了多工作电极的套筒型生物电化学系统装置,并对工作电极分别施加-0.3、-0.5和-0.7 V恒电位。结果表明,在-0.3、-0.5和-0.7 V条件下,电极最大电流密度分别为36.91、241.92和476.41 mA/m^(2),反硝化速率分别为0.88、1.02和1.11 mg/(L·h)。更负的电位有利于微生物利用电极获得电子促进反硝化过程。电极电位调控促进了微生物群落结构的差异分化,3个电位下微生物菌群中占优势菌门均为Proteobacteria、Bacteroidota和Actinobacteriota,优势菌属分别为Chryseobacterium(31.35%)、Unclassified Comamonadaceae(34.22%)和Azoarcus(16.53%)。此外,电极电位调控也会影响反应机理和关键功能基因表达。-0.7 V电位更有利于napAB基因表达,通过细胞色素电子转移路径进行反硝化,而在-0.3、-0.5 V电位下更利于微生物通过narGHI基因的表达进行电子转移完成反硝化。To investigate the denitrification efficiency,nitrogen conversion pathways and corresponding microbial flora functions of bioelectrodes at different potentials,a sleeve-type bio-electrochemical system(BES)device with multiple working electrodes was constructed in this study.Three different constant potentials including-0.3 V,-0.5 V and-0.7 V were applied to the working electrodes simultaneously.Results show that the denitrification rates and current densities are 0.88 mg/(L·h)and 36.91 mA/m^(2) at-0.3V,1.02 mg/(L·h)and 241.92 mA/m^(2) at-0.5 V,1.11 mg/(L·h)and 476.41 mA/m^(2)at-0.7 V,respectively.The maximum denitrification rate and current density are both obtained at-0.7 V,indicating that more negative potential is beneficial for microorganisms to obtain electrons from electrode to support denitrification processes.The microbial community divergence happens as a result of potential regulation.The dominant microorganisms at phylum level at different potentials are all belonged to Proteobacteria,Bacteroidota,and Actinobacteriota,with Chryseobacterium(31.35%),Unclassified Comamonadaceae(34.22%),and Azoarcus(16.53%)as the dominant genera.Additionally,electrode potential regulation shows a significant impact on the expression of functional gene and the reaction mechanism.Under-0.7 V,more napAB genes are expressed indicating that the denitrification is achieved by electron transfer through cytochromes,while,under-0.3 V and-0.5 V,denitrification process is achieved through electron transfer by the expression of narGHI genes.

关 键 词：生物电化学系统 电位调控 反硝化 微生物组成 脱氮 宏基因组 

分 类 号：X703[环境科学与工程—环境工程]