Iron removal by physio chemical way consists of iron oxidation by air followed by sand filtration.
Oxidation can be carried out by various chemicals like chlorine, ozone but is mostly done by compressed air.
Complex bound iron and manganese, e.g. complex bound with humic acids, can be very difficult to remove. In this case oxidation with ozone can be a solution.
Iron removal is based on the precipitation of dissolved iron (Fe2+) into its oxidized form (Fe3+), as Fe(OH)3 or Fe2O3. Iron removal filter is processed catalytic filtration unit when the raw water passed through the layer of compressed air, processed catalyst & quartz filter media respectively. The dissolved ferrous iron salts are converted into insoluble ferric salt and precipitin over the filter bed and then the iron free filtered water comes out. Only backwashing with clear water and compressed air is required for cleaning the bed.