Comparison of Chlorogenerated Disinfection Byproduct Formation from Sequential Use Ozone and Monochloramine with Alternative Disinfection

Humic acid were used as model compound. Four oxidation scenarios (ozone/monochloramine, monochloramine, chlorine/monochloramine, chlorine) were conducted to evaluate the disinfection byproducts formation. The disinfection byproducts formation potential (DBPFP) were detected to compare the types of disinfection byproducts formed from different scenarios. Results showed that ozone/monchloramine and monochloramine significantly decreased the formation of trihalomethanes (THMs) and haloacetic acids (HAAs). But after disinfecting with ozone/monchloramine or monochloramine, some nitrogenous disinfection byproducts such as dichloroacetonitriles(HANs) and chloropicrin(CP) could be produced and reach to a much high concentration. From the examination of residual chlorine, we could found that most of monochloramine and chlorine decay were happened during the first 24 hours, and solution pH should be better controlled during monochloramination to prevent monochloramine autodecomposition.