Abstract
Trichloramine is one of the major chlorinous odor compounds in drinking water. Trichloramine formation potential upon chlorination increased after ozonation at actual water purification processes. The formation potential, however, decreased after following activated carbon process. Thus, the levels of the trichloramine formation potential after activated carbon process was similar to or lower than that before ozonation. It was considered that one of the reasons of the increase of trichloramine formation potential after ozonation was the change of the chemical structures of natural organic matter in the process water by ozonation, and the amounts of reaction sites which affected trichloramine formation potential was decreased. It was also condiered that phenolic groups were important reaction sites for this reaction. Trichloramine formation potential upon chlorinataion decreased when free chlorine concentration decreased and pH of the sample increased at 8.
