Chemical changes of organic compounds in chlorinated water. XIV. Characterization and determination of halogenated organics formed during chlorination of water from the Tama River.

Water samples collected from the Tama River were treated with chlorine under the conditions utilized for water renovation, in order to characterize and determine the halogenated organics formed in this reaction. It was found that the concentrations and compositions of organic halogens in chlorinated river water are strongly dependent on the sampling points. Chlorinated river-water showed total trihalomethane (THM) levels ranging from 26 to 96 micrograms/l. Higher concentrations of THMs and a high ratio of brominated THMs to total THMs were found on chlorination of water samples taken from the midstream of the Tama River, as compared with those observed from the upstream. The range of non-purgeable (NPOX) and n-hexane-extractable organic halogen (EOX) levels in the chlorinated river-water was from 146 to 417 microgram/l and from 15 to 105 micrograms/l, respectively. Gas chromatographic analyses of n-hexane extracts demonstrated that chlorine treatment of river-water not only produces, in addition to THMs, new lower-molecular-weight and chromatographiable organic halogen compounds (COX), but also decomposes the original halogenated organics present. The amounts of THMs, COX, EOX and NPOX in chlorine-treated river-water were found to be dependent on the pH of the solutions.