亚硝酸盐型甲烷厌氧氧化过程影响因素研究

Effect of environmental factors on nitrite-dependent denitrifying anaerobic methane oxidation

亚硝酸盐型甲烷厌氧氧化(Nitrite-dependent denitrifying anaerobic methane oxidation,n-damo)是指微生物在厌氧条件下利用甲烷还原亚硝酸盐的过程,该过程的研究可为污水脱氮减排提供技术支持.采用n-damo富集培养物(荧光原位杂交实验结果表明n-damo功能菌丰度可达73%)为研究对象,着重探讨温度(25,35,45℃)、p H值(5.5~9.5)、甲烷分压(0~98 k Pa)和亚硝酸盐初始浓度(0~6.0 mmol·L-1)对n-damo反硝化速率的影响,以获得最优条件,为n-damo过程在污水处理中的应用提供理论依据.结果表明,在本实验条件下n-damo过程进行的最适温度为35℃,最适p H值为7.5,最适甲烷分压为49 k Pa,最适亚硝酸盐初始浓度为2.4~3.42 mmol·L^(-1).

Nitrite-dependent denitrifying anaerobic methane oxidation（ n-damo） is a denitrification process,which enables the microbes to utilize methane to reduce nitrite under anaerobic condition. Being energy efficient and environment friendly,it is a potential and novel wastewater treatment. In this study,n-damo enrichment（ the abundance of n-damo bacteria is about 73% by the Fluorescence in situ hybridization） was cultured to investigate the effect of temperature（ 25,35,45 ℃）,p H（ 5. 5 9. 5）,partial pressure of methane（ 0 98 k Pa） and nitrite concentration（ 0 4. 4 mmol·L-1） on n-damo process,and the optimal environment factors for the application of n-damo process in wastewater treatment. The results indicated that the optimum temperature,p H,partial pressure of methane and initial concentration of nitrite were 35 ℃,7.5,49 k Pa and 2.4 3.42 mmol·L-1,respectively.