高速公路服务区污水A/O生化处理工艺运行参数研究

STUDY ON THE OPERATING PARAMETER OPTIMIZATION OF A/O PROCESS IN TREATMENT OF EXPRESSWAY SERVICE SEWAGE

通过长期监测确定高速公路服务污水的水质特点,以A/O工艺中试效果为基础探索服务区污水处理站的优化运行参数。正交实验结果表明,对系统TN去除影响最大的因子是回流体积比r,系统推荐的工艺参数为:ρ(MLSS)=4 g/L,r=300%,总HRT=32 h,HRT(A):HRT(O)=1:1.5,缺氧和好氧DO的质量浓度分别为0.5、3.0 mg/L。甲醇为适宜外加碳源,m(C)/m(N)建议控制在8.0左右,系统暂停运行时间不超过24 h。长期稳定运行结果表明,A/O工艺对COD、氨氮、TN和TP的平均去除率分别可以达到80.0%、91.5%、77.3%和65.2%,出水稳定达标。

The characteristics of expressway service sewage were detected through long-term monitoring. The operating parameters of A/O pilot plant were optimized based on the treatment effect of the sewage. Results of orthogonal experiment show that the most important influential factor is reflux ratio on removal of TN, and the optimum technological parameters are recommended as follows： p（MLSS）=4 g/L, r（reflux volum ratio）=300%, Total HRT=32 h, HRT（A）：HRT（O）=1 ： 1.5. and dissolved oxygen concentrationp（DO） in aerobic stage and anoxic stage is 3.0 mg/L and 0.5 mg/L respectively. The best kind of external carbon addition is methanol, and its optimum dosage should be controlled at m（C）/m（N）=8.0. Meanwhile, the suspended time of A/O process should not be lasted over 24 h under intermittent operation model. Result of long-term running shows that the removal rate of COD, ammonia nitrogen, TN, TP could reach to 80.0%, 91.5%, 77.3% and 65.2% in A/O pilot plant respectively. The effluent do get effective guarantee to discharge within the standard stably.