摘要：The precursors of trihalomethane (THM) in aquatic environment were studied. Water samples were collected from 24 points of the Nagara River and the potentials of THM formation were examined. THM was formed even in the water from unpolluted upper streams, and from the middle points of the river near Gifu city the potentials gradually increased. Bromine compounds increased remarkably at the mouth of the river. After allowed to stand the chlorianted sample for 7 days, the amounts of bromoform incresed. River water was fractionated by Sephadex G-50. The potentials THM formation were larger at lower molecular fractions than at higher molecular ones. Humic substances were extracted from leaf mold with distilled water and fulvic acid was fractionated to 4 fractions by molecular weight. In fulvic acid fraction of the above M. W. 1000, both KMnO4 and chlorine consumption had good correlation with the amounts of chloroform formed. From the effluents of night soil treatment plant, bath water and swimming pool water, chloroform was formed. Hymatomelanic acid methanol-water soluble substances were considerd to be important precursors in the effluent. The main precursor at the upper stream of the river is considered to be humic substances made from leaf mold, and those at middle and down stream to be domestic wastes, effluent from night soil treatment plant, industrial effluent, etc,
关键词：trihalomethane;precursor;trihalomethane formation potential;humic substances;river water;effluent from night soil treatment plant;bath water;swimming pool water;leaf mold;fulvic acid
