[Effects of Anions on Bromate Formation During Ozonation of Bromide-Containing Water]

To study the effects of common inorganic anions on bromate formation during ozonation of bromide-containing water, the effects of different mass concentrations of Cl-, HCO3-, and SO(4)2- on bromate formation were investigated in bench-scale test. The mechanisms of these three coexisting anions on bromate formation was analyzed based on the ozone decomposition, HOBr/OBr- formation, and transformation of total bromine species. Our results showed that adding of 3-150 mg.L-1 Cl- can reduce 8. 8%-25. 7% of bromate formation within 60 min. 63. 9% of bromate would be decreased by increasing SO(4)2- concentration from 0 mg.L-1 to 30 mg.L-1 within 20 min. However, more than 6. 4 times the mass concentrations of bromate were formed as HCO3- mass concentrations increased from 0 mg.L-1 to 30 mg.L-1 within 20 min. The production of bromate was slightly increased when HCO3- mass concentrations was above 30 mg.L-1. Under the condition of the same ozone dosage and reaction time, adding of Cl- and SO(4)2- will inhibit the formation of bromate during ozonation, while adding of HCOC3- significantly will increase the production of bromate.