单级自养脱氮系统运行周期内的DO变化研究

Research on Variation Rule of DO in One-stage Completely Autotrophic Nitrogen Removal System

以人工配制的低C/N值废水为处理对象,考察了单级自养脱氮系统在一个反应周期内DO浓度的变化规律及其与含氮物质转化的相关性。结果表明,当DO分别控制在2.0和1.5mg/L时,对TN的去除率分别为69.7%和81.1%,在氨氮转化结束前,DO浓度基本保持不变,到氨氮转化结束时出现DO浓度突然升高的折点。不同DO浓度条件下的试验进一步验证了DO变化特征点的重现性,DO浓度变化特征点可作为判断氨氮转化完成从而可停止曝气的控制点。

Using the synthetic low C/N wastewater as research object, the variation rule of DO concentration in one operation cycle of one-stage completely autotrophic nitrogen removal system was investigated, and the correlation between the variation rule of DO concentration and the conversion of nitrogen compounds was analyzed. The removal rates TN were 69.7% and 81.1% respectively when DO concentrations were controlled at 2.0 mg/L and 1.5 mg/L respectively. DO concentration maintained a constant value before the end of conversion of ammonia nitrogen, and a breakpoint indicating the sudden increase of DO concentration occurred at the end of conversion of ammonia nitrogen. The reproducibility of characteristic points of DO concentration was further verified experimentally under different DO concentrations, revealing that DO concentration can serve as a control point to judge the completion of the conversion of ammonia nitrogen and stop aeration.