Evaluation of Tap Water Quality by Spectrofluorometry

摘要

Spectrofluorometry was applied to the detection of micropollutants in tap water. Tap water contains a small quantity of humic substances, such as chlorinated fulvic acids. Survey of tap water in various parts of Japan revealed that raw water from the river in big cities contains relatively large quantities of those substances. A part of fluorescent substances is eliminated in the purification process and it's fluorescence intensity is reduced by chlorination. Fluorescence intensity is also reduced by ozonation process, but changes little by subsequent chlorination. Thus, Ozone/AC (activated carbon) treatment enables us to reduce both fluorescence intensity and a trihalomethane formation potential. Tap waters in Japan show a lower fluorescence intensity, about 1/10 of those of various cities of the world. Although all the fluorescent substances are not always the chlorinated fulvic acid because of different disinfection Drocesses in foreign countries, more attention should be paid to fluorescent substances in tap water.