Bromate formation in a hybrid ozonation-ceramic membrane filtration system

The effect of pH, ozone mass injection rate, initial bromide concentration, and membrane molecular weight cut off (MWCO) on bromate formation in a hybrid membrane filtration–ozonation reactor was studied. Decreasing the pH, significantly reduced bromate formation. Bromate formation increased with increasing gaseous ozone mass injection rate, due to increase in dissolved ozone concentrations. Greater initial bromide concentrations resulted in higher bromate concentrations. An increase in the bromate concentration was observed by reducing MWCO, which resulted in a concomitant increase in the retention time in the system. A model to estimate the rate of bromate formation was developed. Good correlation between the model simulation and the experimental data was achieved.

► Bromate formation in a hybrid membrane filtration–ozonation system was studied.
► pH depression significantly reduced bromate formation.
► Bromate formation increased with increasing inlet [O3] and inlet gas flow rate.
► Greater initial bromide concentrations resulted in higher bromate concentrations.
► Bromate concentration increased when the MWCO of the membrane was reduced.