To save energy consumption in domestic wastewater treatment, three-stage autotrophic nitrogen removal process including organics removal SBR, partial nitrification SBR and anammox UASB was proposed. At room temperature of (26±1)℃ , short-term effect of aeration rate and MLSS on organic removal process was investigated by seeding activity sludge taken from a pilot-plant reactor of partial nitrification. The results show that both concentrations of NO2- N and NO3- -N were lower than 0. 1 mg · L-1 at various aeration rates and sludge concentrations before the end of COD biodegradation stage. After that, the wastewater entered a difficult-degradating stage in reactor where COD concentration remained at nearly constant level and NO-2-N and NO3 -N concentrations accumulated rapidly and nitrifying-bacteria activity increased. Obviously, nitrification did not occur during the process removing organics under different aeration conditions. Therefore, under various conditions of aeration and sludge concentration the first organics was removed and then partial nitrification to remove NO3 -N. However, for three-stage autotrophic nitrogen removal process, NH4 -N concentration could decrease from 11.6 mg · L-1 to 3.4 mg · L-1 (TN loss) during organics removal process under aeration values of 100 L · h-1 , 60 L · h1 and 20 L · h-1. The peak point of pH profile and the inflexion of DO curve stayed the same with the end of removing organics throughout, and so they could be used as real-time control signals to indicate the end of organic removal process.%为了实现城市污水处理过程中的节能降耗,提出了三段式城市污水自养脱氮工艺,阐述了除有机物SBR在整套工艺中的重要地位,探讨了不同曝气量与污泥浓度条件下,除有机物SBR中有机物的去除特征与规律.结果表明,在不同的曝气量及污泥浓度条件下,COD降解结束前NO2--N与NO3--N的浓度均低于0.1 mg·L-1,反应器进入COD难降解阶段后,NO2--N与NO3--N的浓度快速提高,可以认为在除有机物SBR内有机物的去除和硝化过程是分步进行的,即先进行有机物的去除,而后进行硝化过程.DO曲线与pH曲线的突越点与除有机物过程的终点始终保持一致,可将其作为实时控制参数监测有机物的去除终点,对好氧曝气过程进行实时控制.
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