What chemical is used for oxidizing iron and manganese that needs a reaction basin?

• A. chlorine
• B. chlorine dioxide
• C. potassium permanganate
• D. ozone

Answer: (D)

Iron and manganese removal hinges on oxidizing the two metals so they form insoluble precipitates that can be filtered out. Ozone is a very strong oxidant and is typically introduced into water through a dedicated ozone contact basin. In that basin, ozone dissolves and has enough contact time to react with Fe2+ and Mn2+ before the water moves on to filtration and disinfection. Because ozone decomposes quickly in water, the contact basin ensures the oxidation reaction can complete efficiently, making it the standout choice for oxidizing both metals. Other oxidants can oxidize iron or manganese, but they don’t rely on a dedicated ozone-style contact basin in the same way, so ozone is the most fitting option here.