城镇污水生化处理原位提标技术路径研究

Research on the in-situ standardization technology path for biochemical treatment of urban sewage

随着各地区制定更加严格的污水排放标准,出水水质逐渐向《地表水环境质量标准》(GB 3838-2002)看齐。目前,部分污水处理厂存在进水碳氮比失衡、实际与设计水质相差大、设备选型不合理、运行管理不精细等问题和技术难点,限制了运行效能的进一步提升,开展提标改造势在必行。然而无扩建用地、无法停产改造等难题给水质和水量的提升带来了巨大挑战。另外,随着新工艺、新设备、新技术不断出现,如何选择经济合理、有效适用的技改路径成为了新的发展命题。通过梳理分析我国污水处理现状、高排放标准与技术难点,从运行优化策略、药剂与载体强化策略及工艺改造策略等方面,总结了传统活性污泥法的水质提标和扩容提标措施及其适用范围,提出了现有污水厂从《城镇污水处理厂污染物排放标准》(GB 18918-2002)一级A排放标准提升至《地表水环境质量标准》准Ⅳ类或Ⅲ类水的原位提标技术路径,为污水处理厂改扩建或新建提供技术参考。

With the development of stricter sewage discharge standards in various regions,the effluent quality is gradually in line with the environmental quality standard for surface water.At present,some sewage plants have technical difficulties and problems,such as the imbalance of influent carbon nitrogen ratio,the large difference between the actual and design water quality,unreasonable equipment selection,and imprecise operation management,which limit the further improvement of their operation efficiency.Therefore,it is necessary to carry out standard upgrading and reconstruction.However,problems such as no expansion land and no shutdown and reconstruction have brought great challenges to the improvement of water quality and quantity.In addition,with the continuous emergence of new processes,new equipment and new technologies,how to choose an economic,reasonable,effective and applicable technological transformation path has become a new development proposition.The current situation of sewage treatment in China,high emission standards and technical difficulties were analyzed.The measures for improving water quality and expanding capacity of traditional activated sludge process and their applicable scope were summarized,including operation optimization strategy,chemical and carrier strengthening strategy,and process transformation strategy.The technical path for upgrading existing sewage plants from Class A discharge standard of the Discharge standard of pollutants for municipal wastewater treatment plant to quasi-ⅣorⅢwater of the Environmental quality standards for surface water was proposed,providing technical reference for the renovation,expansion or construction of sewage plants.