污水再生全流程中A/O工艺的深度除磷研究

Study on Advanced Phosphorus Removal in A/O Unit of Integrated Process for Reclamation of Municipal Sewage

采用A/O工艺作为污水处理全流程的首端处理单元,通过调整相关运行参数,在实现深度除磷和降解COD的同时为后续自养脱氮单元提供适宜的进水。在温度为20℃以及进水TP、COD、氨氮、亚硝酸盐氮、硝酸盐氮分别为(6～8)、(300～500)、(70～90)、(0.015～0.25)、(0.4～1.7)mg/L的条件下,将系统HRT控制在5.5 h以下时,出水TP<1 mg/L,硝酸盐氮和亚硝酸盐氮浓度均小于5 mg/L,氨氮平均为68.44 mg/L,对TP的平均去除率为90%,氨氮损失率仅为17%;此外,当曝气池的DO在0.6～0.8 mg/L之间时,系统在抑制硝化反应的同时实现了深度除磷和去除COD。

The A/O process, as the first treatment unit of the integrated process for reclamation of municipal sewage, can achieve advanced removal of phosphorus and COD as well as provide appropriate influent for the follow-up autotrophic denitrifieation units through adjusting the relevant operating parameters. The effluent TP is less than 1 mg/L, both nitrate and nitrite are less than 5 rag/L, and the average ammonia nitrogen is 68.44 mg/L under the conditions of 20℃, TP of 6 to 8 rag/L, COD of 300 to 500 mg/L, ammonia nitrogen of 70 to 90 rag/L, nitrite of 0. 015 to O. 25 mg/L and nitrate of 0.4 to 1.7 mg/L in the influent. The average removal rate of TP is 90% with 17% ammonia nitrogen loss. The system achieves advanced removal of phosphorus and COD while inhibiting nitrification by controlling DO at 0.6 to 0.8 mg/L in aeration tank.