Disinfection Effects and Operating Conditions of Tea Polyphenols Combined with Ozone
ABSTRACT Ozone disinfection is an efficient method, but it has no persistent disinfection effect, which is the main factor restricting its development. However, tea polyphenols are a renewable green resource and have continuous disinfection effect in drinking water treatment. Thus, it is beneficial to make tea polyphenols an auxiliary disinfectant to ozone disinfection, explore the combined disinfection effect of ozone and tea polyphenols, and optimize its operating conditions. The optimal disinfection effect of the combined disinfectant was determined by using a response surface analysis (RSA) This method of experimental design with three factors and three levels was used to establish a regression model for analysis. The results showed that the dosage of tea polyphenols was the most significant influencing factor; combined with ozone, the half life of tea polyphenols was extended from 15 h to 77 h, which could achieve continuous control of network microorganisms. The optimal operating condition of the combined disinfectant was an ozone dosage of 2.5 mg/L, ozone contact time of 25 min, and tea polyphenol dosage of 20 mg/L. The advantages of tea polyphenols and ozone can be well exerted under these conditions, which will ensure the safety of effluent from microbes.