连续流双污泥反硝化同时除磷系统影响因素

目的为了深入研究连续流双污泥反硝化同时除磷系统的主要影响因素,确定系统最佳运行条件.方法以生活污水为研究对象,保持其他运行条件不变,分别改变C/N、BFR、PAHRT的大小,监测系统的除磷脱氮效果,确定系统的最佳运行条件.结果进水C/N（COD/TN）与TP、TN的去除效果密切相关,在3.8～6.0之间,系统可长期稳定运行,对TN、TP、COD的去除率可分别达到83%、92%和86%,而系统的最佳C/N比是在4～5之间;同时BFR在0.33～0.38之间控制得越低TN去除效果越好,如果BFR低于0.28或高于0.48,均会影响系统对TN、TP的去除;PAHRT也不宜过长,如果超过60 min并长时间运行,会破坏污泥沉淀性能,减少聚磷菌群中反硝化聚磷菌的比例,影响系统稳定运行.结论系统进水最佳C/N为4～5,BFR为0.33～0.38,PAHRT应控制在20～30 min较为适宜.

Study on the Affecting Factors of Continuous-flow Two-sludge System

The affecting factors of the continuous-flow two-sludge system for simultaneous biological phosphorus and nitrogen removal were investigated in order to decide on the best working state of the system.For this purpose the experiments of the affecting factors on the system including influent COD/TN ratio(C/N),bypass sludge flow ratio(BFR) and HRT of the post-aeration reactor(PA_(HRT)) were arranged.Long-term experiments showed that when C/N ranged between 3.8 and 6.0,the removal efficiency of TN,TP and COD were 83%,92% and 86% respectively,and the perfect C/N to the system was lying between 4 and 5.As to BFR,it was controlled between 3.3 and 3.8,and the lower it was,the better the removal efficiency could be reached.With BFR either higher than 4.8 or lower than 2.8,the removal efficiency decreased.Furthermore,PA_(HRT) should not be controlled longer than 60 minutes;if so,not only will the settling performance be destroyed but the proportion of denitrifying phosphorus removal bacteria(DPB) in phosphorus accumulating organism(PAO) will decrease,and the system can not operate under steady status.