微量NO2下完全自营养脱氮动力学及运行优化

采用间歇试验研究了微量NO2氛围下,好氧、厌氧氨氧化复合颗粒污泥动力学特性.结果表明,微量NO2能提高O2反应活性,强化好氧氨氧化过程.反应动力学可用Andrews方程描述,NO2半饱和系数和抑制系数分别为1.32,7.11μmol/L.NO2强化厌氧氨氧化过程动力学模型中最大强化系数为43.5,NO2半饱和系数和抑制系数分别为16.9,0.348μmol/L,基础速率系数为0.024.建立了NO2强化完全自营养脱氮动力学模型,并对EGSB反应器中脱氮过程进行了模拟,当DO为0.6mg/L,NO2为3.0μmol/L时,总氮去除率达最大值.根据模拟结果优化反应器运行条件,总氮去除率由26.86%~31.65%提高到58.83%~63.08%,总氮平均去除速率由0.113 kg/(m3·d)提高到0.234kg/(m3·d).

Kinetics and optimizing operation of completely autotrophic nitrogen removal under the atmosphere of trace NO2

The effect of trace NO2 on the kinetic characteristics of coupling aerobic and anaerobic ammonium oxidation (ANAMMOX) in granular sludge was investigated by batch experiments. With trace NO2, aerobic ammonium oxidation process was enhanced by increasing the activity of O2, which was described by Andrews’s model. Half saturate coefficient and inhibition coefficient of NO2 were 1.32μmol/L and 7.11μmol/L, respectively. Anaerobic ammonium oxidation process was also enhanced by NO2. The maximum ANAMMOX enhancing coefficient was 43.5, while half saturate coefficient and inhibition coefficient of NO2 were 16.9μmol/L and 0.348μmol/L, the basic rate coefficient was 0.024 as well. Based on the kinetic analysis under trace NO2, completely autotrophic nitrogen removal process in an expanded granular sludge bed (EGSB) reactor was simulated. It was revealed that nitrogen removal efficiency reached the maximum when DO and NO2 were 0.6mg/L and 3.0μmol/L. Based on the stimulation, the operation of reactor was optimized. The nitrogen removal efficiency increased from 26.86%~31.65% to 58.83%~63.08%, as well as the removal rate increased from 0.113 kg/(m3·d) to 0.234kg/(m3·d).