好氧甲烷氧化耦合反硝化极限脱氮系统的效能及应用

Efficiency and application of aerobic methane coupled to denitrification ultimate denitrification system

摘要:

[目的] 探究甲烷浓度、温度和氮浓度对好氧甲烷氧化耦合反硝化（AME-D）极限脱氮系统的影响，分析该系统微生物群落结构，并对贵阳某污水处理厂尾水进行应用研究。[方法] 采用阶段性实验研究甲烷浓度、温度和氮浓度对系统脱氮效能的影响，通过16S rRNA基因测序技术分析系统中微生物群落结构，利用共焦显微拉曼光谱仪分析实际废水水质变化特征。[结果] 甲烷进气比为3%、温度为30℃、氮浓度为20 mg/L时脱氮效果最好，系统的总氮、氨氮和硝酸盐氮平均去除率分别为93.66%、96.13%和92.25%；系统中的主要甲烷氧化菌分别为Methylosarcina（1.84%）、Methylovulum（0.01%）和Crenothrix（0.14%），以及兼性甲烷氧化菌属Methylocystis（1.9%），主要的亚硝化菌为Nitrosomonas（0.008%），硝化菌为Nitrospira（0.42%），反硝化菌为Hyphomicrobium（1.19%）和Pseudomonas（0.61%）；采用该系统处理贵阳某污水处理厂尾水时，出水总氮平均浓度达到0.96 mg/L，能达到极限脱氮的目的，拉曼光谱分析显示系统对硝酸盐氮和亚硝酸盐氮有较高的去除，甲烷被氧化形成的中间产物可能为醇类或醛类物质，为反硝化菌提供所需碳源。[结论] AME-D极限脱氮由多种微生物协同实现，其功能微生物为甲烷氧化菌、亚硝化菌、硝化菌和反硝化菌，应用研究显示该系统在城镇污水处理系统中具有较大的应用潜力。

Abstract:

[Objective] This research is to analyze the effects of methane concentration, temperature and nitrogen concentration on the aerobic methane coupled to denitrification (AME-D) ultimate denitrification system, the microbial communities in this AME-D system, and the application of this system into the tail water of a sewage treatment plant in Guiyang, China. [Methods] The effects of methane concentration, temperature, and nitrogen concentration on the nitrogen removal efficiency of this system were studied in staged experiments. The microbial community in the system was analyzed by 16S rRNA gene sequencing technology, and changes of the wastewater water quality were analyzed by confocal micro-Raman spectrometer. [Results] With the methane intake ratio of 3%, and the nitrogen concentration of 20 mg/L at 30 ℃, the average removal rates of total nitrogen, ammonia nitrogen, and nitrate nitrogen in the system reached high up to 93.66%, 96.13% and 92.25%, respectively; The dominant methanotrophs in this system were Methylosarcina (1.84%), Methylovulum (0.01%) and Crenothrix (0.14%); the facultative methanotrophs was Methylocystis (1.9%); and the dominant nitroso-bacteria were Nitrosomonas (0.008%), nitrifying bacteria were Nitrospira (0.42%), and denitrifying bacteria were Hyphomicrobium (1.19%) and Pseudomonas (0.61%). Applying this system into the tail water of a sewage treatment plant in Guiyang, the average total nitrogen concentration in the effluent reached 0.96 mg/L, reaching the limit of denitrification. Raman spectrum analysis showed that nitrate nitrogen and nitrite nitrogen can be effective removed in this system. Intermediate products of the oxidized methanotrophs could be alcohols or aldehydes, which can provide the required carbon source for denitrifying bacteria. [Conclusion] AME-D ultimate denitrification was realized by the synergy of microorganisms, including functional microorganisms like methanotrophs, nitroso-bacteria, nitrifying bacteria, and denitrifying bacteria. Research results also exhibited great potential of this system applied into the urban sewage treatment.