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

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 1 000 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.