MODELING DISSOLVED OZONE AND BROMATE ION FORMATION IN OZONE CONTACTORS

Many drinking water utilities that use source waters with significant bromide ion levels are currently seeking disinfection regimes that wil l minimize the formation of brominated disinfection byproducts while p roviding adequate disinfection. While ozonation appears to be a promis ing option for achieving these goals, the uncertainty of future drinki ng water regulations has developed a need for predicting actual disinf ection byproduct formation prior to the costly investment for upgradin g existing treatment facilities. The models developed in this paper pr ovide comparisons of ozonation application methods, providing a basis for minimizing bromate and aiding in future design considerations. The oretical and empirical models for the determination of ozone transferr ed, dissolved ozone concentrations, and bromate formation have been de rived and compared with pilot-scale and full-scale data; a good agreem ent has been observed between the actual data and the predicted data, showing the validity of these models. True-batch bromate formation mor e closely simulated pilot-scale and full-scale data. Bromate formation in one stage vs two stage ozone contactors and different reactor conf igurations have been compared. Ozone gas phase concentration appears t o have an effect on bromate formation as well.