为考察实际高氨氮垃圾渗滤液短程生物脱氮过程DO对以NO2--N为电子受体反硝化动力学的影响,本研究采用缺氧/厌氧UASB-SBR生化系统处理实际高氨氮垃圾渗滤液,在SBR系统实现稳短程生物脱氮(120d运行)的基础上,取SBR反应器内的污泥进行pH8.0条件下不同DO浓度梯度反硝化批次试验,从而确定DO对以NO2--N为电子受体的溶解氧抑制系数(K′O)的影响.试验结果表明,DO对反硝菌的NO2--N还原活性具有明显影响,与缺氧状态相比,DO为0.4和0.6mg·L-1时,其还原活性分别降低了49.0%和16.3%左右.DO与NO2--N还原速率两者呈指数负相关.DO对NO2--N为电子受体K′O具有显著影响,存在明显的分段现象,每一DO范围内,K′O恒定.
The effect of dissolved oxygen (DO) on the kinetics of denitritation using nitrite as electron acceptor was investigated in this study. A lab-scale UASB-SBR system was operated to achieve nitrogen removal via nitrite from landfill leachate with high ammonia concentration. Stable partial nitration was successfully achieved in the SBR after 120 days. Batch tests were performed to assess the effect of DO concentration on the DO inhibition coefficient (K'O) of denitritation using the sludge from the SBR at different DO gradients and constant pH 8.0. DO has a significant inhibitory effect on the activity of denitrifying bacteria. The nitrite reduction rate decreased approximately 49% and 16.3% of its maximum rate at DO concentrations of 0.4 mg·L-1 and 0.6 mg·L-1,respectively. A negative exponential formula was established to describe the relationship between DO concentration and nitrite reduction rate. Distinct values were obtained by linear regression within three different DO ranges (DO≤0.4mg·L-1,0.4 mg·L-1≤DO≤0.72 mg·L-1 and 0.72 mg·L-1≤DO≤1.03 mg·L-1). However,the K'O was constant in each DO range.