Monitoring the Levels of Bromate and Chlorate in Alexandria Governorate Drinking Water in Selected Samples from the City Network and Bottled Water
The bromate and chlorate values detected in most of the bottled water samples were exceeding the permissible limits. Bromate formation increased significantly, if the ozone dose was increased. It was remarkable that, the water samples exceeding the permissible limit of chlorate could be classified as unsuitable for drinking purpose. The variation in bromate and chlorate values in bottled waters could be related to the variation of water temperature and ozone dosing (mg/l). The current results emphasized that bromate (BrO3–) in drinking water was traditionally seen as an ozonation byproduct from the oxidation of bromide (Br–), and its formation during chlorination was usually not significant.
Bromate and chlorate formation was found to be thermally driven by changes in temperature. Increasing temperature helped in increasing bromate and chlorate formation. pH level also had an impact on bromate and chlorate formation. Increasing pH level caused an increase in bromate and chlorate formation. Elevating hydrogen peroxide concentration enhanced bromate and chlorate formation. Increasing alum dose and hence decreasing TOC concentration resulted in an increase in bromate and chlorate formation. Bromate and chlorate in drinking water of WTPs DSs had low chemical toxicity risk. Bromate and chlorate in Egyptian bottled water was under alarming situation from the chemical toxicity. However, some brands might be safer than others.