A single-level biological aerated filter (BAF) was used to treat domestic wastewater. The response surface method (RSM) model was applied to optimize the operating parameters such as hydraulic retention time (HRT), reflux ratio (R), and aeration-stop ratio. The characteristics of the wastewater were analyzed. The results showed the average removal efficiencies for COD, TN, and NH₄⁺-N were 87.77, 75.41, and 87.28%, for a COD/N ratio of 3.44 under the RSM optimized conditions of HRT = 7 h, R = 105%, and aeration-stop ratio of 1:1. The environment was favorable for enhanced denitrification in the 30–70 cm section. The proportion of Proteobacteria showed a valley pattern along the range direction, while Planctomycetes and Nitrospirae were gradually increasing. The microorganisms involved in denitrification were more abundant at the phylum level, notably Proteobacteria (22.87–47.56%), Planctomycetes (6.62–10.68%), Nitrospirae (0.79–3.02%), and denitrifying bacteria were also evident at the genus level, i.e., Flavobacterium (0.21–1.43%). The BAF system with internal reflux-coupled intermittent aeration enhances nitrification and denitrification, thereby facilitating nitrogen removal.

使用单级曝气生物过滤器（BAF）处理生活污水。应用响应面法(RSM)模型优化水力停留时间(HRT)、回流比(R)和曝气停止比等操作参数。分析了废水的特性。结果表明，在HRT = 7 h、R  = 105%的 RSM 优化条件下，COD/N 比为 3.44 ，COD、TN 和 NH ₄ ⁺ -N的平均去除效率分别为87.77、75.41 和 87.28 % , 和 1:1 的曝气停止比。环境有利于加强 30-70 cm 截面的反硝化作用。Proteobacteria的比例沿范围方向呈谷状，而Planctomycetes和Nitrospirae逐渐增加。参与反硝化的微生物是在门电平更丰富，特别是变形菌门（22.87-47.56％），浮霉菌门（6.62-10.68％），硝化螺旋菌门（0.79-3.02％）和反硝化细菌也很明显在属水平，即,黄杆菌(0.21–1.43%)。内回流耦合间歇曝气的BAF系统增强了硝化和反硝化作用，从而促进了脱氮。