Iron Removal and Manganese Filter
Iron in water supplies usually exists in either of the following oxidation states:
- a) Divalent Ferrous Iron (Fe+2) which is the soluble form of iron found in water supplies.
- b) Trivalent Ferric Iron (Fe+3) which is a stable form of iron that is typically insoluble in water.
Manganese usually exists in water supplies in the following oxidation states:
- a) In any oxidation state from Mn0 to Mn+4.
- b) Solublemanganousoxide,Mn+2.
- c) Manganic oxide, Mn+4, the stable form of manganese that is insoluble in drinking water supplies.
When iron removal and manganese filter are found in water that has no dissolved oxygen they exist in the reduced soluble forms. These soluble forms are: divalent ferrous iron, (Fe+2) and manganous oxide, (Mn+2).
Dissolved iron and manganese are removed from water supplies predominately by oxidation and filtration. The soluble ferrous and manganous forms are oxidized to the insoluble ferric and manganic forms. The insoluble ferric and manganic precipitates are then filtered.
Soluble iron and manganese cause the following objectionable problems in drinking water supplies. The EPA has established secondary standards of 0.30 mg/l for iron and 0.05 mg/l for manganese to alleviate these objectionable affects to water consumers and purveyors.
- Metallic and bitter taste and odors.
- Staining of porcelain household fixtures, clothing and swimming pool plaster. Iron causes a reddish color. Manganese causes a blackish color. Iron and manganese in combination cause reddish black color.
- Fouling of water softener resins. Water quality decreases and regeneration costs are significantly increased
- Fouling of cooling water systems. Deposition in water heaters.
- Industrial process water contamination such as food, beverage and textile processing and silicon chip manufacturing.