Bromate formation and control during water ozonation

The effects of important water quality characteristics and treatment processes on bromate formation were investigated along with a review of bromate formation mechanisms. The variables examined include pH, initial bromide concentration, alkalinity, temperature, ozone dose, ammonium, hydrogen peroxide, and dissolved organic carbon level. This array of variables was selected to evaluate the effects of important water quality characteristics and treatment processes on the formation of bromate ion during water ozonation. Isolation and fractionation of natural organic matter (NOM) by ultrafiltration and reverse osmosis membrane techniques allowed assessment of source water variations and the role of NOM molecular size on bromate formation. Results obtained from batch experiments indicate that bromate formation was favored at high pH, initial bromide concentration, alkalinity, temperature, and high ozone dose. On the other hand, increasing dissolved organic carbon (DOC) and ammonium concentration decreased bromate formation. Finally, acid, ammonium, and mannitol addition were proposed as bromate formation control strategies.