Technology-Related Characterization of Hydrophilic Disinfection By-Products in Aqueous Samples

Abstract

Although much benefit has been gained using ozone or chlorine as oxidants and disinfectants in water treatment, both of these substances react with natural organic matter (NOM) to form disinfection by-products (DBPs). Only little is known about their reactions with water constituents, e.g., with high molecular organic compounds such as humics. The combination of size exclusion chromatography and DOC-detection gives more information on the reactions of ozone, OH-radicals, and chlorine with NOM. The objective of this paper is to show results of LC/DOC-analysis of different raw water NOM before and after oxidation and disinfection, respectively. The results were compared with water quality parameters, such as bacterial regrowth potential and DBP formation potential. It will be shown that in all cases of oxidation and disinfection low molecular acids were produced and high molecular compounds were removed. The low molecular organic substances were responsible for higher bacterial regrowth potential. The DBP-formation potential was reduced after preoxidation with ozone. In case of more OH-radical induced pre-oxidation DBP-formation was higher than after ozonation.