Identification of new drinking water disinfection by-products from ozone, chlorine dioxide, chloramine, and chlorine

Many drinking water treatment plants are currently using alternative disinf ectants to treat drinking water, with ozone, chlorine dioxide, and chlorami ne being the most popular. However, compared to chlorine, which has been mu ch more widely studied, there is little information about the disinfection by-products (DBPs) that these alternative disinfectants produce. Thus, it i s not known if the DBPs from alternative disinfectants are safer or more ha zardous than those formed by chlorine. To answer this question, we have set out to comprehensively identify DBPs formed by these alternative disinfect ants, as well as by chlorine. The results presented here represent a compil ation of the last 8 years of our research in identifying new DBPs from ozon e, chlorine dioxide, chloramine, and chlorine. We also include results from recent studies of Israel drinking water disinfected with both chlorine dio xide and chloramine. Over 200 DBPs were identified, many of which have neve r been reported. In comparing by-products formed by the different disinfect ants, ozone, chlorine dioxide, and chloramine formed fewer halogenated DBPs than chlorine.