城镇污水处理厂提标改造的对策分析与工程实践

Countermeasure Analysis and Engineering Practice of Upgrading Urban Sewage Treatment Plant

在不能增加池容的条件下完成污水厂提标改造,工艺的选择成为改造成功的关键。通过对安阳市晁家村污水处理厂(10×10^(4)m^(3)/d)提标改造过程的总结和改造前后运行状况、进出水数据的分析比对,表明在池容受限(5.43×10^(4)m^(3))条件下,投加比表面积620 m^(2)/m^(3)的HDPE悬浮填料(0.37×10^(4)m^(3)),城镇污水厂采用移动床生物膜混合系统(IFAS)工艺,出水可以稳定达到一级A排放标准:2021年水量(出水)负荷率126%,出水COD、BOD5全年可稳定在27、2.5 mg/L以下;出水TN值连续9个月低于12 mg/L,全年平均11.6 mg/L;出水NH_(3)-N值7个月在1 mg/L以下,连续10个月(3~12月)在2 mg/L以下,全年平均1.47 mg/L。2019年~2021年的进出水水质数据,展现了IFAS工艺具有同步脱氮除磷、容积负荷高、抗冲击负荷、不易发生污泥膨胀等优点,同时也需解决好拦截筛网耐用、漂浮物高效拦截两个主要问题。IFAS工艺可以作为城镇污水处理厂可行的、运行稳定的提标改造工艺。

The process selection is the key to the successful upgrading of sewage plant under the condition that the tank capacity cannot be increased.Based on the summary of the upgrading process of Chao Jiacun Sewage Treatment Plant(10×10^(4)m^(3)/d)in Anyang City,and the analysis and comparison of the operation status and inlet and outlet water data before and after the upgrading,it is shown that under the condition of limited tank capacity(5.43×10^(4)m^(3)),the HDPE suspended packing(0.37×10^(4)m^(3))with specific surface area of 620 m^(2)/m^(3) is added.The moving bed biofilm mixing system(IFAS)process is adopted in Chengzhen Sewage Treatment Plant,and the effluent can stably meet the first-level A discharge standard:the water(effluent)loading rate is 126% in 2021,and the effluent COD and BOD5 can be stabilized below 27 mg/L and 2.5 mg/L throughout the year.The effluent TN value was lower than 12 mg/L for 9 consecutive months,and the annual average was 11.6 mg/L.The effluent NH_(3)-N value was below 1 mg/L for 7 months and below 2 mg/L for 10 consecutive months(March-December),with an annual average of 1.47mg/L.The data of inlet and outlet water quality from 2019 to 2021 show that IFAS process has the advantages of simultaneous nitrogen and phosphorus removal,high volume load,impact load resistance,and less sludge bulking.Meanwhile,two major problems,durable interception screen and efficient interception of floating objects,need to be solved.IFAS process can be used as a feasible and stable upgrading process for urban sewage treatment plants.