同步硝化反硝化(simultaneous nitrification and denitrification,简称SND)是氧化沟工艺实现优良脱氮效果的主要原因,为了较好实现SND,采用ORP作为氧化沟工艺SND的控制参数.采用缺氧-厌氧-氧化沟模型对市政污水进行了生物脱氮研究.UORP在-30~30mV,NH4^+和NO3^-的含量均比较低,发生了较好的SND;UORP在30mV以上,出水的总无机氮(TIN)中95%以上为NO3^-,该状况下硝化效果良好,UORP在-30mV以下,硝化不充分,出水的TIN中78%以上为NH4^+;UORP在-30~30mV,TN的去除率在88%以上,SND作用去除的NO3^-占总的NO3^-去除的99%以上;氧化沟中的NH4^+和NO3^-之比的对数与UORP有着很好的相关性,相关系数R=-0.97.
Simultaneous nitrification and denitrification (SND) is the main reason to the high nitrogen removal of oxidation ditch process, To achieve SND at high efficiency, redox potential (ORP) was used as a controlling parameter. This paper finds that: 1) UORP can indicate SND, if UORP, is between - 30 mV to 30 mV, SND progress favorably, but if UORP is more than 30 mV, nitrification can be produced enough, denitrification is low, if UORP is lower than - 30 mV, the result is the reverse to UORP more than 30 inV. 2) If the UORP is between - 30 mV to 30 mV, the rate of total inorganic nitrogen is more than 88 %, the NO^- 3 being removed is about 99 % of the total NO3^- being removed. 3) The logarithm of the ratio of NH4^+ N to NO3^- is a linear correlation, R is - 0.97.