BROMATE FORMATION AND CONTROL DURING WATER OZONATION

The effects of important water quality characteristics and treatment p rocesses on bromate formation were investigated along with a review of bromate formation mechanisms. The variables examined include pH, init ial bromide concentration, alkalinity, temperature, ozone dose, ammoni um hydrogen peroxide,and dissolved organic carbon level. This array of variables was selected to evaluate the effects of important water qua lity characteristics and treatment processes on the formation of broma te ion during water ozonation. Isolation and fractionation of natural organic matter (NOM) by ultrafiltration and reverse osmosis membrane t echniques allowed assessment of source water variations and the role o f NOM molecular size on bromate formation. Results obtained from batch experiments indicate that bromate formation was favored at high pH, i nitial bromide concentration, alkalinity, temperature, and high ozone dose. OR the other hand, increasing dissolved organic carbon (DOC) and ammonium concentration decreased bromate formation. Finally, acid, am monium, and mannitol addition were proposed as bromate formation contr ol strategies.