Division of Environmental Engineering, Faculty of Engineering, Hokkaido University, North-13, West-8, Sapporo 060-8628, Japan.
Division of Environmental Engineering, Faculty of Engineering, Hokkaido University, North-13, West-8, Sapporo 060-8628, Japan; Department of Civil Engineering, Nagaoka National College of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188, Japan.
Bioresour Technol. 2015 Dec;197:15-22. doi: 10.1016/j.biortech.2015.08.054. Epub 2015 Aug 21.
The effects of dissolved oxygen (DO) and pH on nitrous oxide (N2O) production rates and pathways in autotrophic partial nitrification (PN) granules were investigated at the granular level. N2O was primarily produced by betaproteobacterial ammonia-oxidizing bacteria, mainly Nitrosomonas europaea, in the oxic surface layer (<200μm) of the autotrophic PN granules. N2O production increased with increasing bulk DO concentration owing to activation of the ammonia (i.e., hydroxylamine) oxidation in this layer. The highest N2O emissions were observed at pH 7.5, although the ammonia oxidation rate was unchanged between pH 6.5 and 8.5. Overall, the results of this study suggest that in situ analyses of PN granules are essential to gaining insight into N2O emission mechanisms in a granule.
本研究在颗粒层面上考察了溶解氧（DO）和 pH 对自养部分硝化（PN）颗粒中氧化亚氮（N2O）生成速率和途径的影响。在自养 PN 颗粒的好氧表层（<200μm）中，β-变形菌氨氧化菌（主要是亚硝化单胞菌属的欧洲亚硝化单胞菌）主要产生 N2O。由于该层中氨（即羟胺）氧化的激活，N2O 的生成随着主体 DO 浓度的增加而增加。尽管在 pH 6.5 至 8.5 之间氨氧化速率保持不变，但在 pH 7.5 时观察到最高的 N2O 排放。总的来说，本研究结果表明，对 PN 颗粒进行原位分析对于深入了解颗粒中 N2O 排放机制至关重要。
