title: Formation of brominated disinfection by-products and bromate in cobalt catalyzed peroxymonosulfate oxidation of phenol.
abstract: Formation of halogenated disinfection by-products (DBPs) in sulfate radical [Formula: see text] based oxidation processes attracted considerable attention recently. However, the underlying reaction pathways have not been well explored. This study focused on the transformation of Br(-) in cobalt activated peroxymonosulfate (Co(2+)/PMS) oxidation process. Phenol was added as a model compound to mimic the reactivity of natural organic matter (NOM). It was revealed that Br(-) was efficiently transformed to reactive bromine species (RBS) including free bromine and bromine radicals (Br, [Formula: see text] , etc.) in Co(2+)/PMS system. [Formula: see text] played a principal role during this process. RBS thus generated resulted in the bromination of phenol and formation brominated DBPs (Br-DBPs) including bromoform and bromoacetic acids, during which brominated phenols were detected as the intermediates. Br-DBPs were further degraded by excessive [Formula: see text] and transformed to bromate ultimately. Free bromine was also formed in the absence of Co(2+), suggesting Br(-) could be oxidized by PMS per se. Free bromine was incorporated to phenol sequentially leading to Br-DBPs as well. However, Br-DBPs could not be further transformed in the absence of [Formula: see text] . This is the first study that elucidated the comprehensive transformation map of Br(-) in PMS oxidation systems, which should be taken into consideration when PMS was applied to eliminate contamination in real practice.
authors.affiliation: Department of Environmental Science and Engineering, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Kuo
authors.initials: K
authors.lastname: Liu
authors.affiliation: Department of Environmental Science and Engineering, Nanjing Agricultural University, Nanjing, 210095, China. Electronic address: jhlu@njau.edu.cn.
authors.forename: Junhe
authors.initials: J
authors.lastname: Lu
authors.affiliation: Department of Environmental Science and Engineering, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Yuefei
authors.initials: Y
authors.lastname: Ji
mesh_terms: D001959:Bromates / Q000737:chemistry*; D003035:Cobalt / Q000737:chemistry*; D004203:Disinfection / Q000379:methods*; D054879:Halogenation; D010084:Oxidation-Reduction; D010545:Peroxides / Q000737:chemistry*; D010636:Phenols / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D001959:Bromates; D010545:Peroxides; D010636:Phenols; D014874:Water Pollutants, Chemical; C038288:peroxymonosulfate; D003035:Cobalt
keywords: Bromate; Brominated disinfection by-products; Phenol; Reaction pathway; Sulfate radical