Pilot plant study on the formation of bromate during pre-coagulation ozonation.

A pilot plant located in Windsor, Ontario, Canada was used to perform this study, where the effects of bromide concentration, contact time and ozone dosage on bromate formation were studied. The raw water source was the Detroit River. The initial bromide concentrations in the raw water were found to be between 20 and 30 mug/L. The ozone contact time and the transferred ozone dose were varied to determine the effect on bromate formation. During these experiments, it was observed that the increase of initial bromide concentration, ozone contact time and transferred ozone dose, all had a positive effect on bromate formation. At low concentrations of bromide (20--30 mug/L), contact times of 6.5 and 9 minutes, and ozone dosages ranging from 1.2 to 3 mg/L, bromate levels in the contactor effluent were below the interim maximum allowable concentration (IMAC), 10 mug/L. But, at spiked levels of bromide (\u3e100 mug/L), an ozone contact time of 9 minutes and ozone doses between 2 and 3 mg/L, bromate levels exceeded the IMAC. The CT values or ozone exposure values (mg/L·min) had a linear relationship with bromate formation. As the CT values increased, the bromate levels increased as well. A model developed by Ozekin (1994) to predict the formation of bromate for certain water quality parameters and ozonation parameters was used to predict bromate levels for this study. It was observed that the Ozekin model correlated well in the low range of initial bromide concentrations (20--30 mug/L). For the higher levels of bromide (\u3e100 mug/L), the predictions did not correlate well with the experimental data from this study. A modified model, to be used for higher range of bromide (\u3e100 mug/L), was proposed.Dept. of Civil and Environmental Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2000 .G84. Source: Masters Abstracts International, Volume: 40-03, page: 0745. Adviser: N. Biswas. Thesis (M.A.Sc.)--University of Windsor (Canada), 2000