Mainstream nitritation-anammox is of strong interest to energy- and resource-efficient domestic wastewater treatment. However, there lack in-depth studies of pretreatment, tests of actual wastewater, and examination of long-term performance. Herein, an upflow nitritation-anammox granular reactor has been investigated to treat primary effluent with a hybrid anaerobic reactor (HAR) as pretreatment for more than 300 days. This system achieved 92% of COD removal, 75% of which was accomplished by the HAR, and had an average final effluent COD concentration of 22 mg L⁻¹. More than 90% of ammonium was removed in the nitritation-anammox reactor, achieving a nitrogen removal rate of 81.0 g N m⁻³ d⁻¹ in the last stage. The accumulation of sulfate-reducing bacteria in the HAR evidenced the effect of sulfate on COD removal and subsequent nitrogen removal. Anammox bacteria (predominantly Ca. Jettenia asiatica) accounted for up to 40.2% of total granular communities, but their abundance decreased over time in the suspended communities. The dynamics of major metabolisms and functional genes involved in nitrogen conversion were predicted by PICRUSt based on the taxonomic data, providing more insights into the functions of the microbial communities. These results have demonstrated the effectiveness and importance of anaerobic pretreatment to successful mainstream nitritation-anammox.

中文翻译：

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混合厌氧预处理主流上游硝化-厌氧氨系统：长期性能和微生物群落动态

主流硝化-厌氧氨氮对能源和资源效率高的生活污水处理具有浓厚的兴趣。但是，缺乏对预处理，实际废水测试和长期性能检查的深入研究。在本文中，已经研究了上流硝化-厌氧颗粒反应器，以混合厌氧反应器（HAR）作为预处理来处理初级废水超过300天。该系统实现了92％的COD去除率，其中75％是通过HAR实现的，最终废水的平均COD浓度为22 mg L ^-1。在硝化-氨氧化反应器中去除了90％以上的铵，实现了81.0 g N m ^-3  d ^-1的氮去除率在最后阶段。减少硫酸盐的细菌在HAR中的积累证明了硫酸盐对COD去除和随后的氮去除的影响。厌氧氨氧化细菌（主要为亚洲结缕草）占总颗粒群落的40.2％，但随着时间的推移，悬浮群落中细菌的丰度下降。PICRUSt根据分类学数据预测了参与氮转化的主要代谢和功能基因的动力学，从而提供了对微生物群落功能的更多见解。这些结果证明了厌氧预处理对于成功的主流硝化-厌氧氨氧化的有效性和重要性。