RELATIONSHIP BETWEEN BROMINATED THMs, HAAs AND TOTAL ORGANIC BROMINE DURING DRINKING WATER CHLORINATION

摘要

It has been known since the 1970s that chlorine can react with natural organic matter (NOM) to form chlorinated disinfection by-products (DBPs) during drinking water treatment. Naturally present bromide in the source water can be oxidized by chlorine to bromine and the subsequent reaction between bromine and NOM forms brominated DBPs. A substantial number of studies have shown that the formation of trihalomethanes (THMs) and haloacetic acids (HAAs) is shifted to more brominated species with increasing bromide concentrations. The analysis of total organic halogen (TOX) in drinking water indicates that a large fraction of the TOX cannot be accounted for by commonly analyzed DBPs, such as THMs and HAAs. Toxicological and epidemiological studies suggest that brominated DBPs might be more toxic than their chlorinated analogues and that unidentified DBPs may contain substantial amounts of toxicologically important compounds. Therefore, a better understanding of the formation of unknown brominated DBPs during chlorination is necessary.