Numerical Simulation of Bromate Formation during Ozonation of Bromide

The purpose of this study is to develop a kinetic model that links O3 decomposition reactions from the TFG ozone decay model with recognized Br? oxidation reactions, secondary ?OH reactions, and H2O2 reactions in order to improve O3 decay and bromate formation prediction capabilities under multiple water quality conditions. The model was compared with experimentally measured ozone decomposition and final bromate concentration data sets provided by two researchers. The data sets included varying pH (6.5–8.5), initial hydrogen peroxide (0–1 mM), and initial bromide concentration (0.1–1 mM). Model verification was carried out by sensitivity analysis of the rate constants and then optimization of the most sensitive rate constants using the method of least squares. Model predicted ozone decay data was analyzed and compared with measured ozone decay data using R-squared statistic for linear regression model. The model predicted final bromate concentration is analyzed by comparing it with the residual Δ(%) between experimental and model results. The TFG model was effectively tested for multiple data sets and it was found that model prediction was a success both for ozone decay (regression coefficients >0.95 for all experimental conditions but one) and bromate prediction with residual of less than 100% for all experimental conditions except low peroxide dose (<20 μm).