Team Waterhouse, Ozonepedia
Ozone oxidation of iron and manganese is an extremely fast & highly efficient reaction.
Iron and manganese removal is one of the more common uses for ozone in drinking water systems. Iron and manganese are easily oxidized by ozone.
More importantly, the cost of Ozonated Iron-removal plants are much economical - with higher efficacy.
In many ways, high ppm of iron, arsenic and manganese can only be removed by proper Ozonation and has no other efficient alternative.
Iron removal is not only important for maintaining drinking water parameters set by the health regulatory boards, but its removal is also necessary due to the build-up of iron and manganese on pipes, fixtures and other surfaces.
Both Iron Fe(II) and Manganese Mn(II) are soluble (non-removable) in water causing them to flow directly through conventional filtrations without some form of oxidation to transform them into particulates (removable).
Iron Removal process by Ozone
Soluble Iron Fe(II) is called ferrous iron. Ferrous Iron Fe(II) is oxidized to Ferric Iron Fe(III) by ozone. This Ferric Iron Fe(III) will then hydrolyze to form Fe(OH)3 which is a particulate and can be removed by standard filtration.
The oxidation of ferrous iron requires only an electron exchange and therefore is a fast reaction.
Arsenic Removal process by Ozone
Ozone oxidizes toxic arsenic to As(V) state, making it non-toxic, which is even a medicine for several human illnesses.
Hence when its filtered after ozonation, the backwash water is of no harm.
For example, Arsenica is an homoeopathy drug, and As(V) extracted from other sources are even found to be anti-carcinogenic.
Manganese Removal process by Ozone
Soluble Manganese Mn(II) is oxidized by ozone to form manganese dioxide MnO2 which is a particulate and can be easily removed by standard filtration.
Ozone will oxidize iron, arsenic and manganese to form insoluble particulates that can easily be filtered from the water.
Iron, manganese and arsenic after ozonation will build up on the filter bed over time and are removed by back-washable sand filter for these applications.