Bromine Radical (Br• and Br2•–) Reactivity with Dissolved Organic Matter and Brominated Organic Byproduct Formation

• DOI: 10.1021/acs.est.2c00549
• Publication Date: 2022-03-29T18:48:59Z
• Authors: Yu Lei; Xin Lei; Paul Westerhoff; Xingyu Tong; Jianing Ren; Yangjian Zhou; Shuangshuang Cheng; Gangfeng Ouyang; Xin Yang
• Keywords: Reactivity

Dissolved organic matter (DOM) is a major scavenger of bromine radicals (e.g., Br• and Br2•-) in sunlit surface waters during oxidative processes used water treatment. However, the literature lacks quantitative measurements reaction rate constants between DOM information on extent to which these reactions form brominated byproducts. Based transient kinetic analysis with different fractions sources DOM, we determined for ranging from <5.0 × 107 (4.2 ± 1.3) 108 MC-1 s-1, are comparable those HO• but higher than Br2•- (k = (9.0 2.0) 104 (12.4 2.1) 105 s-1). attack aromatic antioxidant moieties via electron transfer mechanism, resulting Br- release minimal substitution into DOM. For example, total was less 0.25 μM (as Br) at environmentally relevant radicals' exposures ∼10-9 M·s. The results give robust evidence that scavenging by crucial step prevent inorganic radical chemistry producing free (HOBr/OBr-) subsequent