Determination and Behavior of Humic Substances as Precursors of Trihalomethane in Environmental Water

Abstract

Humic and fulvic acids in environmental water were determined by UV spectrophotometry after concentration with diethylaminoethyl(DEAE)-cellulose and separation at pH 1 by centrifugation. The ranges of fulvic and humic acids in Katsura, Uji, Kidzu and Yodo Rivers were from about 0.50 to 3.2 mg/l and 0.025 to 0.2 mg/l, except for the sampling points, which were located downstream of a sewage-disposal plant. Fulvic acid was predominant in these rivers. The concentrations of humic substances were high in the summer and low in the winter. The concentrations of humic substances in these rivers decreased fairly much from December of 1992 to August of 1993. The annual changes in the values of humic substances during 1993 to 1996 were smaller than the change from 1992 to 1993. The trends for the seasonal and annual changes in the concentration of the trihalomethane formation potential in Yodo rivers were almost consistent with those of humic substances.