Removing iron and manganese with ozone is something that’s been done for quite a while. This only works when it’s soluble iron (Fe ll) and soluble manganese (Mn ll). Both chemicals are (as the name suggests) dissolved in water and therefore can’t be filtered out. By using ozone, the iron will oxidise into iron hydroxide which can easily be filtered out with a sand filter.
Manganese is oxidised into manganese oxide using ozone, which can also be filtered out easily with a sand filter.
Removing both chemicals is relatively easy using ozone, however, overdosing should be taken into account.