城镇污水处理厂一级A标准运行评估与再提标重难点分析

截至2019年底，全国共有2913座城镇污水处理厂执行GB 18918-2002《城镇污水处理厂污染物排放标准》的一级A标准，占全国城镇污水处理厂总数的53.2%，一级A标准已成为目前国内城镇污水处理厂执行最广泛的排放标准。通过对近6年太湖流域204座执行一级A标准污水处理厂的深入调研，结合全国100多座污水处理厂的全流程分析工作成果，首先系统评估了执行一级A标准的城镇污水处理厂的运行成效，其中太湖流域城镇污水处理厂在一级A提标改造后由于进水量的不断增加和出水浓度的不断降低，污染物削减总量显著提高，对太湖流域有机物、氮、磷减排及太湖富营养化控制做出了积极贡献。然后总结了城镇污水处理厂在运行过程中的常见问题，在进水水质、工艺设计、设备设施选择和维护以及活性污泥功能菌群性能调控等方面仍有进一步完善和优化空间，并提出了针对性的优化运行措施。最后重点探讨新一轮提标改造工作的重难点和对策，提出在新一轮提标改造中，应当重视污水收集系统的提质增效，提高管网质量和输送效率，并建议提标改造前先开展现有工艺的全流程分析，再在此基础上确定采取工艺优化或工程措施。

OPERATION EVALUATION OF URBAN SEWAGE TREATMENT PLANTS IMPLEMENTING GRADE I-A STANDARD AND ANALYSIS ON EMPASSIS AND DIFFICULTIES IN UPGRADING THE STANDARD

By the end of 2019, a total of 2913 urban wastewater treatment plants (WWTPs) in China had implemented the Grade I-A Discharge Standard in China's national standard GB 18918-2002, which accounted for 53.2% of the total WWTPs in China. The Grade I-A Standard has become the most widely implemented discharge standard for WWTPs in China. Based on the deep investigation of 204 WWTPs implementing the Grade I-A Standard of Taihu Basin in recent 6 years, in combination with whole process analysis of more than 100 WWTPs in China, this paper firstly evaluated the operational performance of WWTPs implementing the Grade I-A Standard. Results showed that total amount of pollutants reduction of WWTPs in Taihu Basin had been significantly increased due to the continuous increase of water inflow, and the continuous decrease of effluent concentration after the upgrading of Grade I-A Standard, positively contributing to the emission reduction of organic matter, nitrogen, phosphorus and the eutrophication control in Taihu Basin. Then the common problems in the operation process of WWTPs were summarized. Influent water quality, process design, selection and maintenance of equipment and facilities, as well as the performance control of functional bacterial group in activated sludge still had further improvement and optimization space. Meanwhile, targeted optimization operation measures were put forward. At last, key and difficult points and strategies in the new round of upgrading work were discussed. It is suggested that attention should be paid to improving the quality and efficiency of the wastewater collection system, and the quality and transmission efficiency of the pipe network. And the whole process analysis should be carried out before upgrading. Then the process optimization or engineering measures could be confirmed.