微氧条件下以甲烷为碳源的反硝化实验研究

为探清微氧条件下以甲烷为碳源的反硝化是甲烷好氧氧化偶联反硝化(AME-D),还是甲烷厌氧氧化偶联反硝化(ANME-D),本研究以污水处理厂厌氧污泥为接种物,在微氧条件下以甲烷为碳源进行硝酸盐和亚硝酸盐反硝化的富集培养,考察硝酸盐和亚硝酸盐的反硝化速率,并对富集培养物的微生物群落和甲烷单加氧酶功能基因进行分析.结果表明:微氧条件下硝氮/亚硝氮的还原主要以AME-D过程为主,稳定阶段硝氮和亚硝氮的平均去除速率分别为3.69 mg·L~(-1)·d~(-1)(以N计)和18.04 mg·L~(-1)·d~(-1)(以N计),富集培养物中的优势微生物为甲基球菌科(Methylococcaceae)中的甲基单胞菌属(Methylomonas),相对含量为21.86%.

Experimental study on denitrification using methane as carbon source under microaerobic condition

In order to identify whether denitrification using methane as carbon source under microaerobic condition is aerobic methane oxidation coupled to denitrification (AME-D) or anaerobic methane oxidation coupled to denitrification (ANME-D), the denitrifying enrichment of anaerobic sludge from wastewater treatment plant was carried out using methane as carbon source and NO^-₃/NO^-₂ as nitrogen source under microaerobic condition. The denitrifying rates of NO^-₃ and NO^-₂ were investigated and the microbial community structure was analyzed. The result showed that AME-D played a major role in nitrate and nitrite reduction, and the average denitrification rates of nitrate and nitrite during stable stage were 3.69 and 18.04 mg N·L^-1·d^-1, respectively. The genus of Methylomonas was dominant with the relative abundance of 21.86%.