Effect of the use of hydrogen peroxide on bromate formation in a bubble column

In drinking water treatment plants, ozonation is often used to disinfect, to remove micropollutants and to improve water taste and odour. Ozonation increases organic matter biodegradability before filtration through granular active carbon and reduces the concentration of haloform precursors that react in the final chlorination step. However, by-products that could be detrimental to human health could be formed. For example, bromates, which are classified as carcinogenic compounds by the I.A.R.C, are produced during the ozonation of bromide-containing water. The mechanism of bromate formation is complex, due to the participation of molecular ozone and radical (hydroxyl and carbonate) reactions. The optimisation of the process should allow for a good disinfection and a reduction in the levels of micropollutants, together with low by-product formation.