昆山市某污水处理厂A-A^2/O工艺脱氮效果分析

介绍了昆山市某污水处理厂（A-A^2/O工艺）的实际运行状况。运行结果表明,该工艺对有机物、总磷、悬浮物等污染物均有良好的处理效果,但脱氮效果偏低且不够稳定。通过分析进水水质及运行控制条件对脱氮效果的影响发现,该污水厂水温及进水碳氮比对脱氮效果影响较小,内回流比对反硝化效率影响显著,其主要原因为好氧段过量曝气导致大量溶解氧通过内回流进入缺氧反硝化池,消耗有机碳源并抑制反硝化过程,导致反硝化效率偏低。但好氧段保持较高溶解氧强化了A2/O工艺在低温条件下的硝化效果。

An Analysis of Nitrogen Removal Efficiency of A^2/O Process in a Sewage Treatment Plant of Kunshan

This paper introduces the actual operation（A-A2/O process） in a sewage treatment plant in Kunshan City.The result shows that the process effectively treats the organic matter,total phosphorus,suspended solids and other pollutants,but the nitrogen removal is low and not so stable.By analyzing the effect of the water quali-ty and operational control conditions on the removal,it is found that the water temperature in the wastewater treatment plant and the carbon and nitrogen ratio in the water have little effect on the nitrogen removal,but the reflux ratio greatly effects the denitrification the efficiency,which is mainly caused by the fact that the excessive aeration of the good oxygen in the substantial section of dissolved oxygen leads to the entrance of the much dis-solved oxygen into the anoxic denitrification tank through the reflux,which consumes the organic carbon and in-hibits the denitrification process,resulting in the low denitrification efficiency.However,the good oxygen can keep a high dissolved oxygen,strengthening the nitrification effect of A^2/O process at low temperature.