This study deals with the effect of aeration control strategies on the nitrogen removal efficiency and nitrous oxide (N₂O) emissions in a partial nitritation–anammox reactor with granular sludge. More specifically, dissolved oxygen (DO) control, constant airflow and effluent ammonium (NH₄⁺) control strategies were compared through a simulation study. Particular attention was paid to the effect of flocs, which are deliberately or unavoidable present besides granules in this type of reactor. When applying DO control, DO setpoints had to be adjusted to the amount of flocs present in the reactor to maintain high nitrogen removal and reduce N₂O emissions, which is difficult to realize in practice because of variable floc fractions. Constant airflow rate control could maintain a good nitrogen removal efficiency independent of the floc fraction in the reactor, but failed in N₂O mitigation. Controlling aeration based on the effluent ammonium concentration results in both high nitrogen removal and relatively low N₂O emissions, also in the presence of flocs. Fluctuations in floc fractions caused significant upsets in nitrogen removal and N₂O emissions under DO control but had less effect at constant airflow and effluent ammonium control. Still, rapid and sharp drops in flocs led to a peak in N₂O emissions at constant airflow and effluent ammonium control. Overall, effluent ammonium control reached the highest average nitrogen removal and lowest N₂O emissions and consumed the lowest aeration energy under fluctuating floc concentrations.

本研究探讨了曝气控制策略对颗粒污泥的部分亚硝化-厌氧氨氧化反应器的脱氮效率和一氧化二氮 (N _{2 O) 排放的影响。}更具体地说，通过模拟研究比较了溶解氧 (DO) 控制、恒定气流和流出铵 (NH ₄ ^{+ ) 控制策略。}特别注意絮状物的影响，在这种类型的反应器中，除了颗粒之外，它们有意或不可避免地存在。在应用 DO 控制时，DO 设定值必须根据反应器中存在的絮凝物数量进行调整，以保持高脱氮率并减少 N ₂O 排放，由于絮凝物比例可变，在实践中难以实现。恒定的气流速率控制可以保持良好的脱氮效率，而与反应器中的絮凝物分数无关，但在 N ₂ O 缓解方面失败。根据流出物中的铵浓度控制曝气会导致高氮去除率和相对低的 N ₂ O 排放量，即使在存在絮凝物的情况下也是如此。在 DO 控制下，絮凝物部分的波动会导致氮去除和 N ₂ O 排放的显着干扰，但在恒定气流和流出氨控制下影响较小。尽管如此，絮状物的快速和急剧下降导致 N _{2达到峰值}恒定气流和流出氨控制下的 O 排放。总体而言，在絮凝物浓度波动的情况下，出水铵控制达到了最高的平均氮去除率和最低的 N ₂ O 排放量，并且消耗了最低的曝气能量。