Ozone has been used for a long timeforn the removal of soluble iron (Fe II) and soluble manganese (Mn II). Both substances are (as the name implies) dissolved in water which makes them extremely hard to remove by normal filtration techniques. Through the use of ozone soluble iron will be oxidized to iron hydroxide. With a sand filter iron hydroxide is easy to remove.
Manganese is oxidized by ozone into manganese dioxide which is also simply to remove by sand filtration. Overdosing ozone in manganese applications will result in the formation of permanganate which will turn the purple in color. Theoretically it is possible to calcualte the correct ozone dose but a complete chemical analysis of the water should be available. Even then it is difficult to calculate the exact dose.
Removal of iron and manganese with ozone is relatively simple but you should be careful in applying the right dose. In water in which the two substances are prevent ozone will first react with iron. After the iron is almost completely oxidized manganese will be oxidized.