探讨生物电化学强化厌氧氨氧化(anammox)脱氮工艺,使用双室微生物电解槽(MEC)构建了具有耦合厌氧氨氧化阴极的生物电化学系统。具体来说,在0.2V的外加电压下,在30℃下进行了不同进水总氮浓度的暗孵育分批实验,结合循环伏安法等多种表征方法研究了反硝化强化机理,电化学阻抗谱和高通量测序方法。结果表明,总氮去除率为96.9%±0.3%,当初始总氮浓度为200、300和400mg/L时,分别获得97.3%±0.4%和99.0%±0.3%,分别。此外,阴极电极生物膜表现出良好的电化学活性。高通量测序结果表明,外加电压富集了其它反硝化官能团,包括脱衣瘤,Limnobacter,氨氧化细菌SM1A02和Anaerolineaceae,欧洲亚硝基单胞菌和亚硝基螺旋体,除了厌氧氨氧化细菌.这些电化学活性微生物由铵氧化外电原(AOE)和反硝化电致营养剂(DNE)组成。连同厌氧氨氧化细菌CandidatusBrocadia,它们构成了反硝化系统的微生物群落结构。AOE与DNE之间的直接种间电子转移加强是进一步进步体系总氮去除率的根本缘由。
To investigate the bioelectrochemical enhanced anaerobic ammonia oxidation (anammox) nitrogen removal process, a bioelectrochemical system with coupled anammox cathode was constructed using a dual-chamber microbial electrolysis cell (MEC). Specifically, a dark incubation batch experiment was conducted at 30 ℃ with different influent total nitrogen concentrations under an applied voltage of 0.2 V, and the enhanced denitrification mechanism was investigated by combining various characterization methods such as cyclic voltammetry, electrochemical impedance spectroscopy and high-throughput sequencing methods. The results showed that the total nitrogen removal rates of 96.9%±0.3%, 97.3%±0.4% and 99.0%±0.3% were obtained when the initial total nitrogen concentration was 200, 300 and 400 mg/L, respectively. In addition, the cathode electrode biofilm showed good electrochemical activity. High-throughput sequencing results showed that the applied voltage enriched other denitrifying functional groups, including Denitratisoma, Limnobacter, and ammonia oxidizing bacteria SM1A02 and Anaerolineaceae, Nitrosomonas europaea and Nitrospira, besides the anammox bacteria. These electrochemically active microorganisms comprised of ammonium oxidizing exoelectrogens (AOE) and denitrifying electrotrophs (DNE). Together with anammox bacteria Candidatus Brocadia, they constituted the microbial community structure of denitrification system. Enhanced direct interspecies electron transfer between AOE and DNE was the fundamental reason for the further improvement of the total nitrogen removal rate of the system.