低基质浓度下UASB厌氧氨氧化的脱氮性能及颗粒污泥特性

Characteristics of granular sludge and nitrogen removal performance in ANAMMOX-UASB reactor fed with low strength substrate

采用升流式厌氧污泥床(up-flow anaerobic sludge blanket,UASB)反应器,通过逐步提高进水流量,考察低基质(NH+4-N为16.6 mg.L-1,NO-2-N为19.8 mg.L-1)条件下,厌氧氨氧化(anaerobic ammoniumoxidation,ANAMMOX)反应器的运行性能。实验结果表明:在低基质浓度条件下可以实现高效ANAMMOX脱氮并形成颗粒污泥。反应器对NH+4-N和NO-2-N的平均去除率分别为93.3%和94.6%;逐步将UASB反应器的水力停留时间(hydraulic retention time,HRT)由1.26 h缩短至0.14 h,获得的容积氮去除速率为5.73 kgN.m-3.d-1;在此工况下获得的厌氧氨氧化污泥颗粒呈红褐色,粒径分布主要集中在0.5～0.9 mm,平均粒径为0.73 mm。

The performance of anaerobic ammonium oxidation （ANAMMOX） was investigated by increasing influent flow rate stepwise in up-flow anaerobic sludge blanket （ UASB ） reactor, with low strength substrate （19.8 mg NO2ˉ-N · L-1 and 16.6 mg NH＋-N · L-1）. The results showed that high volumetric nitrogen removal rate could be achieved and granular sludge could be formed in UASB reactor fed with low strength substrate. The average removal efficiencies of NH4＋-N and NO2ˉ-N were 93.3% and 94.6 %, respectively. The hydraulic retention time （HRT） was progressively shortened from 1.26 h to 0.14 h, and when HRT was 0.14 h, the volumetric nitrogen removal rate was 5.73 kg N · m ˉ3 · d ˉ1 .The ANAMMOX granules were rufous in color and the majority （81.81%） of granules was in the range of 0.5--0.9 mm with the average of 0.73 mm.