Brominated trihalomethane formation in halogenation of humic acid in the coexistence of hypochlorite and hypobromite ions
| Autor: | Kiyoshi Teranishi, Akio Ichimura, Keiko Ichihashi |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
chemistry.chemical_classification
Environmental Engineering Ecological Modeling Inorganic chemistry Sodium hypobromite Hypochlorite Halogenation Pollution chemistry.chemical_compound Trihalomethane chemistry Sodium hypochlorite Hypobromous acid Humic acid Hypobromite Waste Management and Disposal Water Science and Technology Civil and Structural Engineering |
| Zdroj: | Water Research. 33:477-483 |
| ISSN: | 0043-1354 |
| Popis: | Brominated trihalomethanes (Br-THMs) such as CHCl 2 Br, CHClBr 2 , and CHBr 3 are produced by the reaction of hypobromite with humic acid in the presence of hypochlorite. In the presence of excess NaOCl, addition of NaOBr enhanced the formation of Br-THMs but reduced the formation of CHCl 3 . The product distribution of THMs was affected by the ratio of [NaOBr]/[NaOCl] and was independent of pH and reaction time. In the presence of excess NaOBr, the yield of CHBr 3 only increased linearly with the NaOCl concentration added. However, the other three THMs were hardly produced even though NaOCl concentration was increased up to 0.5 of the [NaOCl]/[NaOBr] molar ratio. Our results suggest that in the process of THM formation, hypochlorite ion reacts effectively with humic acid in the oxidation reaction and hypobromous acid plays a predominant role in the electrophilic substitution when both of hypohalites are present. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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