By-products of chlorination: Specific compounds and their relationship to total organic halogen
Over the past decade a great deal of scientific interest has focused on the hydrophobic halogenated byproducts of drinking water disinfection, principally chloroform and other trihalomethanes. Natural aquatic humic material has been implicated as a precursor for these substances. More recent data suggests that the importance of chloroform as an aqueous chlorination product of humic materials may have been overstated. This study reviews the progress to date on the identification and quantification of more hydrophilic chlorination by-products, such as trichloroacetic acid, from a variety of humic substances. Qualitative data are summarized from several previous studies and compared with more recent experiments performed in the authors' laboratory on isolated aquatic humic material. Data are reported which support the hypothesis that these hydrophilic substances are produced in greater yield than chloroform and account for a significant fraction of the total organic halogen materials produced.
