同步脱氮除磷工艺中好氧池最适氧浓度研究

AB工艺无厌氧、缺氧段,氮、磷的去除率低,不具备深度脱氮除磷功能。而A2/O工艺具有同步脱氮除磷功能,可以作为AB工艺改造方案之一。试验以实际生活污水为对象,研究好氧池中不同的溶解氧浓度范围内系统对COD、氮、磷的去除效果。试验结果表明,好氧池DO对COD的去除影响较小,出水平均值达到21.9mg/L;对氨氮的去除则起着关键作用,在DO为3.0mg/L以下时,氨氮的去除率随着DO的增大而升高;DO为1.5～2.5mg/L时总氮去除效果最佳,过低、过高对总氮的去除都不利;总磷的去除效果几乎不受好氧池DO的影响,但厌氧池和缺氧池的释磷、吸磷过程却受DO的影响变化较大。系统中厌氧池和缺氧池同时出现了反硝化和吸磷作用,但尚不能判断是否存在反硝化除磷现象。

Research on Optimal DO Concentration in Aerobic Pool of Simultaneous Biological Nitrogen and Phosphorus Removal Process

A pilot-scale nutrient removal activated sludge system, based on A2/O configuration, was used to treat municipal sewage. In the experiment, the nutrient removal affected by DO concentration in the aerobic stage was observed at given operating condition. Results showed the effect of DO concentration on COD removal was much smaller, and the removal rate of COD, had a tendency to rise with the increase of DO concentration under 3.0mg/L. The optimal DO concentration for total nitrogen removal was between 1.5 to 2.5mg/L, lower or higher would increase the effluent concentration. Anaerobic phosphorus release and anoxic phosphorus uptake were distinctly affected by DO concentration, but the effluent total phosphorus stable. In the system, denitrifying and phosphorus uptake were both observed, but it was denitrifying phosphorus removal or not was not judged.