Integrated Application of Combined Constructed Wetland Systems in Upgrading Tailwater Treatment for Petrochemical Industrial Park Wastewater Plants
摘要
针对设计规模5 000 m3/d的石化工业园区污水厂尾水中的有机污染物、氮、磷等指标提标改造的需求,采用"反硝化深床滤池—两级垂直潜流—表面流"组合人工湿地工艺对尾水进行深度净化.为期一年的运行监测结果表明,湿地系统运行稳定、净化效果良好,运行良好,COD、TN、NH3-N、TP的平均出水浓度分别为22.8、7.3、0.4、0.1 mg/L,平均去除率分别为36.8%、42.9%、88.2%、51.3%,BOD5出水在检测限以下,出水水质优于DB 51/2311－2016《四川省岷江、沱江流域水污染物排放标准》.该项目投资及运行成本较低,具有优异的生态效益及社会效益,对岷江流域及周边生态保护起到重要作用,可为大型尾水湿地的建设提供参考.
To meet the requirements for further upgrading of effluent quality related to organic pollutants,nitrogen,phosphorus,and other parameters in the tailwater from a 5 000 m3/d wastewater treatment plant(WWTP)in a petrochemical industrial park,a combined constructed wetland system integrating a denitrification filter,two‑stage vertical subsurface flow wetland,and surface flow wetland was employed for advanced purification.One‑year operational monitoring demonstrated that the integrated wetland system achieved stable and efficient purification performance:the average effluent concentrations of COD,TN,NH3‑N,and TP were 22.8 mg/L,7.3 mg/L,0.4 mg/L,and 0.1 mg/L,respectively,corresponding to average removal efficiencies of 36.8%,42.9%,88.2%,and 51.3%.The effluent BOD ₅ concentration remained below the detection limit.The final effluent quality met and exceeded the discharge limits specified in the Discharge Standard of Water Pollutants for Minjiang River and Tuojiang River in Sichuan Province(DB 51/2311－2016).This project is characterized by relatively low capital investment and operational costs,along with remarkable ecological and social benefits.It plays a vital role in ecological protection within the Minjiang River Basin and adjacent regions,and thus can provide a valuable reference for the construction and application of large‑scale tailwater purification wetlands.
