多级A/O工艺设计及其在应急污水处理工程中的应用

Design of Multistage A/O Process and Its Application in Emergency Sewage Treatment

为有效缓解资阳市第二污水处理厂现状处理能力不足导致的污水溢流问题,改善周边水生态环境,新建了规模为5000 m 3/d的应急污水处理工程。该工程采用“多级A/O+磁混凝沉淀”组合工艺,对其中的多级A/O工艺段进行了深化设计,并对本项目的实际运行效果进行了分析。深化设计结果表明,多级A/O反应器级数宜采用2级,流量分配比宜为7∶3,污泥回流比宜为100%。运行期间的监测数据表明,出水指标均满足《四川省岷江、沱江流域水污染物排放标准》(DB51/2311-2016),其中的COD Cr、TP和TN的去除率分别为96.6%、97.6%和87.2%。通过设置初段硝化液回流,充分发挥初级缺氧池的脱氮能力,使多级A/O工艺的脱氮效率得到了强化。该项目采用的组合工艺简单有效,出水效果好,为城市溢流污水的高标准排放提供了一种更优选择。

An emergency sewage treatment project with a design capacity of 5000 m 3/d was built in Ziyang to alleviate the problem of insufficient treatment capacity of Ziyang Second Sewage Treatment Plant and improve the quality of water environments in the surrounding areas.Multistage A/O+magnetic coagulation was adopted for this project,detailed design were performed for the multistage A/O process,the actual operation effect of this project was analyzed.The detailed design results showed that two-stage reactors should be used as multistage A/O reactors of this project,the flow distribution ratio should be 7∶3,and the sludge reflux ratio should be 100%.Monitoring data obtained during the operation indicated that all discharge indexes met the Discharge Standards for Water Pollutants in Minjiang and Tuojiang River Basins of Sichuan Province(DB51/2311-2016),and the removal rates of COD Cr,TP and TN were 96.6%,97.6%and 87.2%,respectively.The nitrogen removal rate of the multistage A/O process was improved by reflux of the first-stage nitrification liquid,which gave full play to the nitrogen removal capacity of the primary anoxic tank.The combination process was simple and efficient,with excellent effluent effect.This project provides a better solution for dealing with sewage overflow in the future.