短程硝化过程碱度变化规律与控制对策研究

Study on Change and Control of Alkalinity in SHARON Process

通过动态试验研究了短程硝化过程的碱度变化及其与pH值和氨氮容积去除率的关系。结果表明:当pH值为7.37时,常温短程硝化的反应速率达到最大值,为1.64 kg/(m3.d);保持最适pH值所需的碱度随氨氮容积去除率的升高而增大。测得短程硝化最低碱度保有量为1 660 mgCaCO3/L,碱度当量为5.41 mgCaCO3/mgN。反应体系内的pH值与碱度呈非线性关系;当pH值为7.0～7.8时,pH值随碱度的变化较缓,有利于碱度调控;最适碱度投加量为1 770～2 008mgCaCO3/L,宜多次或连续流加。

The dynamic experiments were carried out to investigate the variation of alkalinity in SHARON process, as welt as the relation of alkalinity to pH and volumetric removal rate of ammonia nitrogen. The results show that the maximum reaction rate of SHARON obtained at normal temperature and pH 7.37 is 1.64 kg/（ m3 · d）. To maintain a suitable pH, the alkalinity needed would be raised as volumetrie removal rate of ammonia nitrogen increases. The minimum alkalinity requirement in the system is 1 660 mgCaCO3/L, and the alkalinity equivalent is 5.41 mgCaCO3/mgN. A non-linear relation exists between pH and alkalinity. The pH change is relatively small in the range of 7.0 to 7.8, which favors the alkalinity eontrol. The continuous or intermittent addition modes should be used to keep an optimal alkaline concentration of 1 770 to 2 008 mgCaCO3/L.