Fractionation and chlorination of organic carbon in water from Yinluan River, Tianjin, China

Total organic carbon in unpolluted water from Yinluan River, Tianjin, China was fractionated into five operational defined fractions of particulate organic carbon, hydrophobic compounds, humic substances, non-humic anions, and other hydrophilic compounds using a multi-step filtration and adsorption scheme. The organic carbon contents and the trihalomethane formation potential of these fractions were determined. It was demonstrated that about half of the dissolved organic carbon in the sample is humic substances which is quite active in term of chlorination reaction. Particulate organic carbon is also an important precursor of the volatile halogenated hydrocarbons. All other fractions, which account for another half of the dissolved organic carbon, contribute to a relatively small percentage of the trihalomethanes produced during the chlorination experiment. It was concluded that humic substances, dissolved or suspended, are the most important precursor of halogenated hydrocarbons during chlorination, owing to their high abundance and trihalomethane formation potential.This study was supported by the National Excellent Young Scientist Fund of China.