Mechanistic Aspects of the Formation of Adsorbable Organic Bromine during Chlorination of Bromide-containing Synthetic Waters
| Autor: | Anna Heitz, Sebastien Allard, Markus Heryanto Langsa, Urs von Gunten, Cynthia Joll |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Bromides
Halogenation 0208 environmental biotechnology chemistry.chemical_element 02 engineering and technology 010501 environmental sciences 01 natural sciences Water Purification Electrophilic substitution Electron transfer chemistry.chemical_compound Bromide Dissolved organic carbon polycyclic compounds Chlorine Environmental Chemistry Organic chemistry 0105 earth and related environmental sciences Bromine Chemistry Water General Chemistry 6. Clean water 020801 environmental engineering Disinfection Environmental chemistry Water Pollutants Chemical |
| Zdroj: | Environmental sciencetechnology. 51(9) |
| ISSN: | 1520-5851 |
| Popis: | During chlorination of bromide-containing waters, a significant formation of brominated disinfection byproducts is expected. This is of concern because Br-DBPs are generally more toxic than their chlorinated analogues. In this study, synthetic water samples containing dissolved organic matter (DOM) extracts and bromide were treated under various disinfection scenarios to elucidate the mechanisms of Br-DBP formation. The total concentration of Br-DBPs was measured as adsorbable organic bromine (AOBr). A portion of the bromine (HOBr) was found to react with DOM via electrophilic substitution (≤40%), forming AOBr, and the remaining HOBr reacted with DOM via electron transfer with a reduction of HOBr to bromide (≥60%). During chlorination, the released bromide is reoxidized (recycled) by chlorine to HOBr, leading to further electrophilic substitution of unaltered DOM sites and chlorinated DOM moieties. This leads to an almost complete bromine incorporation to DOM (≥87%). The type of DOM (3.06 ≤ SUVA254 ≤ 4.85... |
| Databáze: | OpenAIRE |
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