DO对膜生物反应器中同步硝化反硝化的影响

Influence of dissolved oxygen on simultaneous nitrification and denitrification in membrane bioreactor

采用人工配制的生活污水作为原水，考察了在膜生物反应器（MBR）中不同溶解氧（D0）对于同步硝化反硝化效果的影响．结果表明，将试验条件控制在TN容积负荷为0．35kgN／（m^3·d）、HRT为6h、SRT为30d、pH为7～8、温度为25～28℃、C／N为9时：在反应器DO的质量浓度为0．6mg／L条件下，可获得62．5％的NH4^＋-N去除率、91．1％的反硝化率和58．3％的SND率；在反应器D0的质量浓度为1．0mg／L条件下，可获得90．8％的NH4^＋-N去除率、90．4％的反硝化率和82．5％的SND率；在反应器DO的质量浓度为1．4mg／L时，可获得93．3％的NH4^＋-N去除率、77．0％的反硝化率和72．1％的SND率．

The man-made domestic wastewater was used as raw water to investigate the effects of different amount of dissolved oxygen on the simultaneous nitrification and denitrification （SND） in the membrane bioreactor. The result shows that under the experiment conditions of volumetric loading 0.35 kgN/ （m^3·d）, hydraulic retention time （HRT） 6 h, sludge retention time （SRT） 90 d, pH value 7-8, temperature 25-28 ℃, carbon/nitrogen （C/N） 9, for DO of 0.6 mg/L in the bioreactor, removal rates of NH4^＋-N, denitrificafion, SND are 62.5 %, 91.1% and 58.3 %, respectively; for DO of 1.0 mg/L in the bioreactor, those are 90.8 %, 90.4 % and 82.5 %, respectively; and for DO of 1.4 mg/L in the bioreactor, those are 93.3%, 77.0% and 72.1%, respectively. These effects can be explained through the anoxic micro-environment existing in the microbiologic floc.