不同工况下一体式生物滤柱反应器的氮去除特征

Characteristics of Nitrogen Removal in an Integrated Biofilter Reactor under Different Operating Conditions

以一体式生物滤柱反应器为研究对象,在氮负荷为0.60 kg/(m3·d)、碳氮比为0.17、曝气量为(50±10)m L/min和温度为(30±2)℃条件下,通过调整进水氨氮浓度和水力停留时间研究进水氨氮浓度变化对氮去除的影响及反应器中微生物功能的区划。连续183 d的运行结果表明,当进水氨氮浓度分别为600、400和800 mg/L时,总氮平均去除负荷分别为0.487、0.465和0.498 kg/(m3·d)。3个工况下的进水氨氮都约有一半在反应器底部的好氧段被转化为亚硝态氮,在顶部的厌氧段氨氮与亚硝态氮均呈线性减少,且其线性减少速率随进水氨氮浓度增加而变大。与此同时,随着进水氨氮浓度的提高,好氧区微生物的氨氮利用速率(AUR)和亚硝酸盐利用速率(NUR)以及厌氧区微生物的比厌氧氨氧化活性均得到提高,且在相同进水氨氮浓度下,好氧段活性污泥的AUR和NUR均大于生物膜的对应值。

An integrated biofilter reactor was studied under the condition of the influent nitrogen load being 0.60 kg/（m^3 · d）, the ratio of carbon and nitrogen being 0.17, the aeration rate being （50 ±10） mL/min and the temperature being （30 ±2） ℃. The effect of NH4^＋ - N concentration on the removal of nitrogen and microorganism distribution in the biofilter were investigated by adjusting influent nitrogen concentration and hydraulic retention time. The results of 183 days continuous operation showed that the average removal load of TN was 0. 487, 0. 465 and 0. 498 kg/（m^3 · d） when the influent NH4^＋ - N concentration was 600, 400 and 800 mg/L respectively. Furthermore, one half of the influent NH4^＋ - N was approximately converted to NO2- - N in the aerobic region of the bottom while both NH4^＋ - N and NO2^- - N were linearly decreased in the anaerobic region of the top and the decrease rate increased with the increase of influent NH4^＋ - N concentration under the above operating conditions. Meanwhile, the ammonium uptake rate （AUR） and nitrite uptake rate （NUR） of the microorganism in the aerobic region and the specific ANAMMOX activity （SAA） in the anaerobic region were improved with the increasing of influent NH4^＋ - N concentration. In addition, the AUR and NUR of the activated sludge were higher than those of the biofilm in the aerobic region under the same influent NH4^＋ - N concentration.