新冠肺炎期间武汉涉疫废水应急处置工作及思考

Emergency Treatment of Wastewater from Quarantine Sites and Hospitals in Wuhan during the COVID-19 Epidemic Outbreak

针对新冠肺炎疫情中可能存在通过城市下水道传播新冠病毒的风险,武汉市根据疫情发展状况,参考相关科研成果和工程标准,在确保城市下水道系统通畅的同时,对涉疫废水采取适当应急消毒措施。采用次氯酸钠为主要消毒剂,对医院、方舱和隔离点的涉疫废水,投加有效氯分别为50和80 mg/L时,接触时间分别大于1.5 h和1.0 h,出水余氯分别大于6.5和10 mg/L;对于无化粪池的留观点和康复驿站,在下水道起端投加消毒剂,接触时间大于10 min,投加有效氯分别为20和10 mg/L,出水余氯控制在6.5~8 mg/L之间;对泵站转输污水不投加消毒剂;对通沟污泥采用浓度为1000 mg/L的有效氯进行表面消毒,喷洒量为100~300 m L/m^2。截至2020年3月下旬,武汉市涉及城市下水道系统工作的人员无一例感染,消毒工作也未对污水处理厂进水水质造成较大冲击,武汉市整体水环境状况良好。在应急处置行动中也发现存在缺少对病毒的基础研究成果、现有检测结果对实际评价病毒传播的指导性不足以及应对城市水环境病毒风险的应急策略和杀灭方法研究有限等问题。建议结合基础性研究成果,完善类似应急条件下城市水务管理和水环境保护方面的标准和程序。

There was the risk of transmitting new coronavirus through urban sewer system during the novel coronavirus pneumonia outbreak.According to the development of the epidemic situation,the appropriate emergency measures should be taken to disinfect the epidemic wastewater in Wuhan while ensuring the urban sewer system is smooth with reference to relevant research results and technical codes.As the main disinfectant,sodium hypochlorite was used to disinfect the wastewater from quarantine sites and hospitals.When the effective chlorine was 50 and 80 mg/L,the contact time was more than 1.5 h and 1.0 h,the residual chlorine in effluent was more than 6.5 and 10 mg/L,respectively.For the disinfection of wastewater in quarantine sites and recovered patient isolation without septic tank,when the effective chlorine added at the beginning of the sewer was 20 and 10 mg/L and the contact time was more than 10 min,the residual chlorine in effluent was 6.5-8 mg/L.No disinfectant was added to the transfer sewage of pumping station,and the effective chlorine concentration of 1000 mg/L was used to disinfect the surface of the sewer sludge,and the spray intensity was 100-300 mL/m^2.At the end of March,no case of infection for the staff worked in the urban sewer system was found in Wuhan,and the disinfection work did not cause a great impact on the influent quality of the sewage treatment plant,and the overall water environment in Wuhan was in good condition.However,it was also found that there were some problems such as the lack of basic research on virus,insufficient guidance of the existing test results for the actual evaluation of virus transmission,and the limited research on emergency strategies and killing methods to deal with the risk of urban water environment virus.It was suggested that the standards and procedures for urban water management and water environmental protection under similar emergency conditions should be improved in the light of basic research results.