Enhanced formation of bromate and brominated disinfection byproducts during chlorination of bromide-containing waters under catalysis of copper corrosion products.
Copper corrosion products (CCPs) in water distribution pipes may catalyze the reactions among disinfectant, natural organic matter (NOM), and bromide (Br(-)). This study investigated the simultaneous formation of bromate (BrO3(-)) and brominated disinfection byproducts (Br-DBPs) during chlorination of Br(-)-containing waters in the presence of three CCPs (i.e., CuO, Cu2O, and Cu(2+)). In a synthetic water, both oxidant decay and BrO3(-) formation were enhanced by CCPs, whereas the presence of humic acid (HA) significantly inhibited BrO3(-) formation due to its competition for HOBr to form Br-DBPs. In the HOClBr(-)CuO system, the BrO3(-) yield increased obviously with increasing CuO dose and initial Br(-) concentration, while the catalytic formation of Br-DBPs was rather limited. A molar conversion (Br(-) to BrO3(-)) of 22.1% was observed under CuO catalysis, compared with little conversion in the absence of CuO. In the HOClBr(-)Cu2O/Cu(2+) systems, Cu2O or Cu(2+) mainly enhanced the formation of Br-DBPs, with enhancement ratios of 69.9% and 50.1%, respectively. The degree of enhancement on Br-DBPs formation became more apparent with increasing pH, while that on BrO3(-) formation reached maximal at pH 7.6. The catalytic formation of Br-DBPs and BrO3(-) by CCPs was also verified in three filtered real waters, although to a lesser extent because of the water matrix effect. In mechanism, the CCPs promoted the formation of BrO3(-) and Br-DBPs through catalyzing the HOBr disproportionation pathway and the reaction of HOBr toward HA, respectively.
Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuang-qing Road, Beijing 100085, China; University of Chinese Academy of Sciences, 19 Yu-quan Road, Beijing 100049, China.
Jun
J
Hu
Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuang-qing Road, Beijing 100085, China; University of Chinese Academy of Sciences, 19 Yu-quan Road, Beijing 100049, China. Electronic address: qiangz@rcees.ac.cn.
Zhimin
Z
Qiang
Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuang-qing Road, Beijing 100085, China; University of Chinese Academy of Sciences, 19 Yu-quan Road, Beijing 100049, China.
Huiyu
H
Dong
Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuang-qing Road, Beijing 100085, China; University of Chinese Academy of Sciences, 19 Yu-quan Road, Beijing 100049, China.
Jiuhui
J
Qu
D001959:Bromates; D001965:Bromides; D002384:Catalysis; D003300:Copper; D003343:Corrosion; D004203:Disinfection; D054879:Halogenation; D014874:Water Pollutants, Chemical; D018508:Water Purification
D001959:Bromates; D001965:Bromides; D014874:Water Pollutants, Chemical; D003300:Copper
Bromate; Brominated disinfection byproducts; Catalysis; Copper corrosion products; Water pipe