城镇污水处理厂消毒设施运行调研与优化策略

我国《城镇污水处理厂污染物排放标准》(GB 18918—2002)将粪大肠菌群数列为出水基本控制指标之一,要求污水处理过程中必须进行消毒,以降低病原微生物对人畜产生的健康风险。为了解污水处理消毒设施运行的效果,对全国56座城镇污水处理厂进行了调研,分析了消毒单元存在的问题并提出应对措施。调研结果表明,采用次氯酸钠和二氧化氯作为消毒剂的污水处理厂数量占调研总量的91. 6%。次氯酸钠和二氧化氯消毒的优势在于持久性效果较好以及运行管理相对简单。但调研数据显示,72%的污水处理厂有效氯投加量为1～4 mg/L,14%的污水处理厂有效氯投加量过高,超过了6 mg/L;消毒接触时间≥30 min的污水处理厂仅占43%,消毒接触时间≤10 min和≤2 min的污水处理厂分别占28%和17%;此外,50%的污水处理厂未对消毒后的总余氯含量进行测试,在已检测该指标的污水处理厂中,总余氯浓度≥0. 20 mg/L的占70%。针对调研中发现的问题,结合文献报道以及试验数据,提出了污水处理厂消毒设施优化运行建议,并展望了未来的主要研究方向,以期为城镇污水处理厂更合理地设计、运行消毒设施提供理论依据和技术指...

Investigation and Optimization Strategies on the Operation of Disinfection Facilities in Municipal WWTPs

Since fecal coliform is one of the basic effluent control indexes in Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant(GB 18918-2002),disinfection is required as part of the wastewater treatment process to reduce the risk of pathogenic microorganism on human and animal health.A total of 56 municipal wastewater treatment plants(WWTPs)were investigated in this study to analyze the operation effect of disinfection facilities.Disinfection unit problems are summarized and countermeasures are proposed.The results of this study show that 91.6%of municipal WWTPs use sodium hypochlorite and chlorine dioxide as disinfectants which have the advantages of enhanced durability,relatively simple operation,and management.Results also show that effective chlorine dosage was between 1 mg/L and 4 mg/L in 72%of WWTPs,rising to over 6 mg/L in 14%of plants.Data show that 43%of WWTPs had more than 30 minutes disinfection contact time while 28%and 17%had contact times less than ten minutes and two minutes,respectively.In addition,50%of WWTPs did not test total residual chlorine after disinfection;and this concentration was higher than 0.20 mg/L in 70%of tested plants.In view of the issues revealed by this study,a number of suggestions for the optimal operation of WWTP disinfection facilities are proposed based on the literature and new experiment data.Future research directions are also proposed in order to provide a theoretical basis and guidance for the design and operation of municipal WWTP disinfection facilities.