村镇污水处理厂提标改造的对策分析及工程实践

Countermeasure Analysis and Engineering Practice of Upgradation and Reconstruction in Rural Sewage Treatment Plant

分析了在《四川省岷江、沱江流域水污染物排放标准》(DB 51/2311-2016)背景下,村镇污水处理厂提标改造所面临污水处理能力不足、难以稳定达标等共性问题,提出了分类分区指导、重点优化处理工艺的应对策略。通过调节水质水量、强化脱氮除磷效果、控制尾水SS浓度、增设除臭装置等工程措施,达到改善岷江、沱江流域水环境质量的目的。结合成都市金堂县土桥镇等11座村镇污水厂提标改造工程进行了案例分析,结果表明:采用预处理+改良AAO+管式紫外消毒组合工艺,TN、SS、TP、COD、NH3-N和BOD5平均去除率分别可达63.6%、93.7%、92.9%、85.3%、97.1%和96.1%,出水水质能够稳定达到《城镇污水处理厂污染物排放标准》(GB 18918-2002)一级A标,符合DB 51/2311-2016的要求。该项目显著削减了金堂县村镇污水的污染负荷,对保护沱江水环境具有实际意义。

Under the background of the Discharge Standard of Water Pollutants for Minjiang and Tuojiang River Basins in Sichuan Province(DB51/2311-2016),common problems such as insufficient capacity of sewage treatment and difficulty in reaching the standard were analyzed.Strategies of classifying and partitioning guidance,and optimizing processing technology were put forward.Water environmental quality of the Minjiang and Tuojiang river basins was improved by adjusting water quality and quantity,strengthening the effect of nitrogen and phosphorus removal,controlling SS concentration of tailwater and adding deodorizer.Combined with the sewage plant upgradation and reconstruction project of 11 villages and towns,such as Tuqiao town of Jintang County in Chengdu city,case analysis was carried out.The results indicate that the average removal rates of TN,SS,TP,COD,NH3-N and BOD5 in 11 wastewater treatment plants are 63.6%,93.7%,92.9%,85.3%,97.1%and 96.1%,respectively,by adopting the combined process of pretreatment+modified AAO+tube ultraviolet disinfection.The effluent water quality can stably reach Level l-A standard specified in the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant(GB18918-2002),and meet the requirements of DB51/2311-2016.This project has remarkably reduced the sewage pollution load of 11 towns in Jintang County,which is of practical significance to protect the water environment of Tuojiang River.