Discussion on Influencing Factors and Control Range of Disinfection Effect in Waterworks during the COVID-19 Outbreak

ABSTRACT

This paper studied the influencing factors of disinfection effect in water purification process and the influence of external demand on the water purification process to ensure that the effective virus inactivation rate of waterworks can meet the requirements of microbiological safety during the COVID-19 outbreak. The results showed that the effluent turbidity should be no more than 0. 3 NTU to meet the requirements of coagulation sedimentation filtration process for virus 2-lg removal rate under the condition of the fixed source water temperature and pH value. On the basis of the above,with the monitoring of the effluent turbidity,water level of clean water tank,water quantity of waterworks and residual chlorine by real-time online instruments,the CT value of the clean water tank was controlled and adjusted within an appropriate range in real time,so that it not only met the 4-lg virus inactivation rate but also reduced the risk of disinfection by-products. Finally,a virus reduction rate of above 6-lg was achieved with the treatment process of waterworks,which could meet the biological safety requirements of drinking water during the epidemic,and have a sufficient safety margin.