周期循环式活性污泥法工艺优化提升低碳氮比城镇污水脱氮效能研究

Cyclic Activated Sludge System-based Process Optimization to Improve Denitrification Efficiency of Low C/N Municipal Wastewater

碳氮比(C/N)是制约污水净化过程脱氮效率的重要因素之一。以周期循环式活性污泥法(CASS)工艺为基础,分别考察了排水比、曝气时间以及进水模式对C/N=1.8的低碳源生活污水脱氮效果的影响。研究结果表明,在低C/N值进水下,排水比是影响CASS脱氮效果的最主要因素。当排水比分别为30%、40%和50%时,CASS工艺出水的TN平均质量浓度分别为17.8 mg·L-1、9.5 mg·L-1和6.6 mg·L-1,TN去除效果随排水比增加而显著提升;因此,对于CASS工艺而言,排水比宜根据C/N进行适当调整,而不应该统一设置成30%。

Carbon-to-nitrogen ratio(C/N)is one of the most important factors affecting aerobic denitrification effect. Based on the cyclic activated sludge system(CASS)process with low-carbon(C/N=1.8)influent,the effects of drainage ratio,aeration time,and water intake mode on denitrification effect are investigated separately.The results show that limited by the influent carbon source concentration,the drainage ratio is the main factor affecting the nitrogen removal efficiency. The average total nitrogen(TN)concentration of CASS effluent was17.8 mg·L-1,9.5 mg·L-1 and 6.6 mg·L-1 when the drainage ratio was 30%,40% and 50%,respectively;Therefore,for CASS process, the drainage ratio should be adjusted appropriately according to the carbon nitrogen ratio instead of being set to 30%.