不同曝气推流式亚硝化试验研究

Study on Nitrosation in Plug Flow Reactors under Different Aeration Conditions

为探讨不同曝气对模拟生活废水亚硝化的影响,常温（22-25℃）下在两组相同的廊道推流式反应器（R1、R2）中,沿程曝气方式为好氧/缺氧/好氧/缺氧,曝气总量为6 L·min^-1,分别采用渐减曝气、渐升曝气研究了3个不同曝气量梯度（R1为4.0-2.0、4.5-1.5、4.8-1.2 L·min^-1,R2为2.0-4.0、1.5-4.5、1.2-4.8 L·min^-1）下模拟生活废水的亚硝化。结果表明,在曝气总量相同的条件下,渐升曝气有利于提高COD去除率及总氮去除率,当曝气量梯度为1.5-4.5、1.2-4.8L·min^-1时,出水COD可达到一级A标准;而渐减曝气的氨氮去除负荷及氨氧化率略高,当曝气量梯度为4.8-1.2 L·min^-1时,平均氨氧化率为58.6%,平均亚硝化率在95%以上,出水NO2？-N/NH4＋-N比例均值为1.34,符合厌氧氨氧化工艺进水对NO2？-N/NH4＋-N比例要求。

In order to investigate the influence of aeration on simulated domestic wastewater nitrosation, three different aeration gradients were applied in two corridor plug flow reactors under room temperature（22-25℃）. An aerobic/anoxic/aerobic/anoxic aeration procedure was used and the total aeration rate was 6 L·min^-1. Reactor R1 employed a tapered aeration mode（4.0-2.0, 4.5-1.5, 4.8-1.2 L·min^-1）, while reactor R2 employed an increasing aeration mode（2.0-4.0, 1.5-4.5, 1.2-4.8 L·min^-1）. The results show that the increasing aeration mode is better than the tapered aeration mode on COD and total nitrogen removal under the same total aeration rate. The effluent COD was lower under this increasing mode with a gradient of 1.5-4.5 and 1.2-4.8 L·min^-1, which satisfies the first level A criteria specified in the Discharge Standard of Pollutants.The tapered aeration mode has higher ammonia nitrogen removal loads and ammonia oxidation rates. The per ammonia oxidation rate was 58.6% and the per nitrite accumulation rate was over 95% under a gradient of 4.8-1.2 L·min^-1, and the per ratio of nitrite to ammonia was 1.34 in effluent, which meets the demand of the ANAMMOX process.