A recent study in the Journal Ozone Science and Enginnering has shown that electrolysis followed by volatilization can remove Br from drinking water and as a result lower the formation of bromate from ozone water treatment.
This is an important issue since a large number of water sources contain Br ion. Ozone can react under the proper conditions of pH, Br ion concnetration and other factors to form bromate. Bromate is regulated by the EPA as a possible carcinigen and it is limited in driking water to less than 10 ppb. Recent studies have indicated that the correlation between bromate and cancer may be weaker than thought, but the regulatory limitation remains in palce. As a result, ozone use has been limited to water sources with low Br levels.
A complication with the process is that electrolysis can produce chlorine whcih also reacts with ozone. Dechlorinating agents need to be added and the amount of ozone required adjusted to compensate for the ozone demand of the water. When this was done, the study showed that the reductions in bromate formation due to ozone were proportional to the reduction in the Br ion levels in the water.
Theoretically at least, it should be possibel to mitigate bromate formation due to ozonation by pretreating the water using electrolysis to reduce Br levels. This would expand the range of source water that could benenfit from ozone drinking water treatment.