Volumetric oxygen transfer coefficient (K_La) is an important parameter affecting oxygen transfer and nitrogen conversion during biological wastewater management. However, how the generation of nitrous oxide (N₂O) responds to the variation of K_La levels is unclear. In this study, N₂O generation via the main pathway, which was confirmed to be nitritation, at different K_La levels was investigated in a partial nitritation-anammox (PN-A) reactor run as a sequencing batch reactor. The results showed that N₂O generation in the PN-A process, which was described using the maximum N₂O generation rate (MGR), the duration of N₂O generation (DG), and the N₂O generation factor, was affected by K_La levels and the limiting factors of the nitritation process, i.e., oxygen transfer and nitritation activity. DG always decreased with the increase of K_La, indicating that the process of N₂O generation lasted for a shorter time at higher K_La. With the increase of K_La, MGRs remarkably increased when oxygen transfer was the limiting factor, while slightly reduced when nitritation activity became the limiting factor. As a result, with the increase of K_La levels, the N₂O generation factor remarkably increased at lower K_La levels when oxygen transfer was the limiting factor, but significantly reduced at higher K_La levels when nitritation activity became the limiting factor. These results revealed how N₂O generation via nitritation responded to different K_La levels and the limiting factors of the nitritation process. Based on these results, practical suggestions to mitigate the N₂O generation in PN-A process operated in a batch mode were recommended.

体积氧传递系数（K _L a）是影响生物废水管理过程中氧传递和氮转化的重要参数。然而，尚不清楚一氧化二氮（N ₂ O）的产生如何响应K _L a水平的变化。在这项研究中，N ₂ ö代经由主通路，这被确认为亚硝化，在不同ķ_大号一个水平是在部分亚硝化-厌氧氨氧化（PN-A）反应器运行的顺序间歇反应器的影响。结果表明，PN-A过程中会产生N ₂ O，这是使用最大N _2来描述的O生成速率（MGR），N ₂ O生成的持续时间（DG）和N ₂ O生成因子受K _L a水平和硝化过程的限制因素，即氧转移和硝化活性的影响。DG总是随着K _L a的增加而降低，表明N ₂ O的生成过程在较高的K _L a下持续的时间较短。随着K _L a的增加，当氧气转移是限制因素时，MGRs显着增加，而当硝化活性成为限制因素时，MGRs略有减少。结果，随着K _L a含量的增加，当氧气转移成为限制因素时，N ₂ O生成因子在较低的K _L a含量时显着增加，但在较高的K _L a含量时，亚硝化活性成为极限，N ₂ O生成因子显着降低。因子。这些结果揭示了通过硝化作用产生的N ₂ O如何对不同的K _L a作出反应水平和硝化过程的限制因素。根据这些结果，提出了一些实用的建议，以减轻以批处理方式运行的PN-A工艺中N ₂ O的产生。