Kinetic Study of HAAs Formation in Chlorinated Drinking Water: Effect of pH, HOCI, and Ozone Dosage

摘要

This study investigated the trend of haloacetic acids (HAAs) formation as function of pH, HOCl, and ozone dose. The comprehensive kinetic model was developed to predict HAAs formation in drinking water treatment train consisting of the pre-chlorination and the ozonation process, which is the frequently adopted practice in some water utilities in Korea. It was found that the HAAs formation rate was greatly influenced by hypochlorous acid (HOCl) or hypochlorite ion (Ocl-) species distribution of the free chlorine. Higher pH led to a reduced concentration of HAA formation potential (HAAFP) due to the low reactivity of Ocl- toward the HAA precursors present in water. In ozonation, OH radicals (OH?) play an important role in removing HAA precursors. The kinetic model to predict HAA precursor removal with ozone was developed to control HAAs.