Bromate formation in bromide-containing waters irradiated by gamma rays

The formation of bromate,a classified potential carcinogen,is of great concern when disinfection processes are used for treating high-bromide drinking waters.Bromide-containing aqueous solutions with various additives were irradiated by;Co γ source.With a 2.0 kGy irradiation of N;O-saturated solutions at initial bromide concentrations of 180.2μgl;,416.9μgl;,663.1μgl;and 823.9μgl;.79.5%,84.0%,87.3%and 88.3%of bromide ions were transformed to bromate,respectively.Addomg CO;/HCO;or NO;ions into N;Osaturated bromide solutions,the amount of bromate ions formed decreased with increasing concentrations of the additives.On the other hand,the bromate concentration was all below the detection limit of 1 μgl;whenever N;O was not added to quench e;and H.The results indicated that γ-rays irradiation could be used as a disinfection process,instead of ozonation,to comply with upcoming more stringent regulations,especially in waters containing high concentrations of bromide.