Formation and toxicity of brominated disinfection byproducts during chlorination and chloramination of water: A review

Disinfection byproducts (DBPs) in drinking water exhibit considerable adverse health effects; recent focus is on the brominated disinfection byproducts (Br-DBPs). The chlorination and chloramination of bromide ion containing water produce reactive bromo species, which subsequently react with natural organic matter (NOM) to yield Br-DBPs. The possible reactions involved in generating DBPs are presented. Identified Br-DBPs include bromomethanes, bromoacetic acid, bromoacetamides, bromoacetonitriles, and bromophenols. Mixed chloro- and bromo-species have also been identified. Pathways of the formation of Br-DBPs have been described. The concentration of Br- ion, pH, reaction time, and the presence of Cu(II) influence the yield of DBPs. The effects of water conditions on the production of Br-DBPs are presented. The epidemiological studies to understand the potential toxic effects of DBPs including Br-DBPs are summarized. Brominated DBPs may have higher health risks than their corresponding chlorinated DBPs. A potential role of an emerging alternate disinfectant, ferrate ((FeO2-)-O-VI (4)), in minimizing DBPs is briefly discussed.