Iron removal

Iron removal - Deferrisation

Iron and Manganese

Manganese is a rather abundant metal in the Earth’s crust, especially in the mineral called pyrolusite. Like any other metal, it can penetrate aquifers due to the natural erosion of rocks.
In waters where manganeseis present, it is likely that iron is also present.

Manganese is an essential trace element for life and is present in enzymes that perform fundamental biological functions.
This metal is part of the class of trace elements called “micro-elements”. The name derives from the fact that, for human health, these elements must be taken in the order of milligrams per day.

Excessive absorption of manganese is highly harmful to health, particularly the nervous and respiratory systems. Massive and continuous exposure to manganese can promote the onset of Parkinson’s disease.

For these reasons, European Directive 98/83/EC sets the maximum threshold for manganese in water intended for human consumption at 0.05 mg/l (four times lower than the threshold for iron).

Iron is the most abundant metal on Earth. As well as posing a health risk, it can cause aesthetic problems: yellow or red staining of surfaces coming into contact with it or linen, as well as giving an unpleasant taste to the water.

Deferrisation and demanganisation by filtration on quartzite and pyrolusite

Manganese and iron can be easily removed from water by oxidation followed by filtration on quartzite and pyrolusite.
Iron and Manganese can be removed by a filtration process that combines the mechanical action of quartzite with the catalytic action of pyrolusite, this process is called deferrisation.
This technique, except for rather low concentrations of Fe or Mn, requires that the oxidative-reductive potential of water to be raised so that metals can precipitate in the form of oxides and hydroxides and thus be retained by the quartzite. 
Pre-oxidation can be carried out by insufflating atmospheric oxygen or by injecting oxidising substances (e.g. sodium hypochlorite) into a tank where the water to be treated is stored.
By contrast, the addition of pyrolusite allows for catalytic oxidation; the iron and manganese ions are in fact oxidised by the resin itself and remain trapped in the filtering material.

Some of our projects

Getting in touch with us is easy. Use the form below and request a free consultation today.

Manganese and iron can be easily removed from water by oxidation followed by filtration on quartzite and pyrolusite. Iron and Manganese can be removed by a filtration process that combines the mechanical action of quartzite with the catalytic action of pyrolusite, this process is called deferrisation. This technique, except for rather low concentrations of Fe or Mn, requires that the oxidative-reductive potential of water to be raised so that metals can precipitate in the form of oxides and hydroxides and thus be retained by the quartzite.  Pre-oxidation can be carried out by insufflating atmospheric oxygen or by injecting oxidising substances (e.g. sodium hypochlorite) into a tank where the water to be treated is stored. By contrast, the addition of pyrolusite allows for catalytic oxidation; the iron and manganese ions are in fact oxidised by the resin itself and remain trapped in the filtering material.