Bromate from the use of Chlorine in Water Treatment

Work was undertaken to study the concentration of bromate in commercial hypochlorite solutions and the effect of storage time, and to assess the possibility of bromate formation during chlorination. The report concludes that a change from the use of chlorine gas to hypochlorite solutions will result in an increase in bromate concentration in treated water. The chlorine concentration of a stored hypochlorite solution decreases with time whereas the bromate concentration stays relatively constant. Therefore, the yse of hypochlorite solutions stored for prolonged periods will increase the likelihood of exceeding the WHO GV of 25 ug 1 - 1. If a lower bromate standard (e. g. 3 ug 1- 1) were set, then does of commercial hypochlorite of ,1mg 1- 1 could result in the limit being exceeded.