The limited efficiency of nitrogen removal has traditionally hindered wide application of simultaneous nitrification and denitrification (SND) technology. Here, the nitrogen removal characteristics of a sequencing batch reactor were studied by adopting a strategy of a step-feeding mode, synergistic regional oxygen limitation, and a mixed carbon source. The changes of the microbial population succession and nitrogen metabolism functional genes were analyzed. This strategy provided a favorable level of dissolved oxygen and continuous carbon sources for driving the denitrification process. The total nitrogen removal efficiency and SND rate reached 92.60% and 96.49%, respectively, by regulating the ratio of sodium acetate to starch in the step feed to 5:1. This procedure increased the relative abundance of denitrifying functional genes and induced the growth of a variety of traditional denitrifying bacteria and aerobic denitrifying bacteria participating in the process of nitrogen removal. Overall, this work offers a new strategy for achieving efficient SND.

传统上，有限的脱氮效率阻碍了同步硝化反硝化（SND）技术的广泛应用。在此，采用分段进料模式、协同区域限氧和混合碳源的策略研究了序批式反应器的脱氮特性。分析了微生物种群演替和氮代谢功能基因的变化。该策略为驱动反硝化过程提供了有利水平的溶解氧和连续碳源。将分步进料中乙酸钠与淀粉的比例调节为5:1,总氮去除率和SND率分别达到92.60%和96.49%。该过程增加了反硝化功能基因的相对丰度，并诱导了多种参与脱氮过程的传统反硝化细菌和好氧反硝化细菌的生长。总体而言，这项工作为实现有效的 SND 提供了一种新策略。