Reactions of Monobromamine and Dibromamine with Phenolic Compounds and Organic Matter: Kinetics and Formation of Bromophenols and Bromoform

• Published in: Environmental science & technology 2023-11, Vol.57 (47), p.18981-18990
• Main Authors: Mensah, Anette T, Xiang, Yingying, Berne, Florence, Soreau, Sylvie, Gallard, Hervé
• Format: Article
• Language: English
• Subjects: Ammonia; Decomposition; Decomposition reactions; Disinfection; Organic matter; pH effects; Phenolic compounds; Phenols; Rate constants; Resorcinol; Tribromophenol
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/acs.est.3c00935

Monobromamine (NH Br) and dibromamine (NHBr ) produced from reactions of hypobromous acid (HOBr) with ammonia can react with phenolic structures of natural organic matter (NOM) to produce disinfection byproducts such as bromoform (CHBr ). The reactivity of NH Br was controlled by the reaction of the bromoammonium ion (NH Br ) with phenolate species, with specific rate constants ranging from 6.32 × 10 for 2,4,6-tribromophenol to 1.22 × 10 M s for phenol. Reactions of NHBr with phenol and bromophenols were negligible compared to its self-decomposition; rate constants could be determined only with resorcinol for pH > 7. At pH 8.1-8.2, no formation of CHBr was observed from the reaction of NH Br with phenol while the reaction of NH Br with resorcinol produced a significant concentration of CHBr . In contrast to NH Br, a significant amount of CHBr produced with an excess of NHBr over phenol was explained by the reactions of HOBr produced from NHBr decomposition. A comprehensive kinetic model including the formation and decomposition of bromamines and the reactivity of HOBr and NH Br with phenolic compounds was developed at pH 8.0-8.3. Furthermore, the kinetic model was used to evaluate the significance of the NH Br and NHBr reactions with the phenolic structures of two NOM isolates.