Iron For Water And Seawater

Natural waters contain variable, but minor, amounts of iron, despite its universal distribution and abundance. Iron in ground waters is normally present in the ferrous (Fe2+), or soluble state, which oxidizes easily to ferric (Fe3+) iron on exposure to air. Iron can enter a water system from leaching of natural deposits, iron-bearing industrial wastes, effluents of pickling operations, or from acidic mine drainage.

Iron in domestic water supply systems stains laundry and porcelain, causing more of a nuisance than a potential health hazard. Taste thresholds of iron in water, 0.1 mg/L for Fe2+ and 0.2 mg/L for Fe3+, result in a bitter or astringent taste. Water used in industrial processes must contain less than 0.2 mg/L of total iron.

Three methods of colorimetric iron analysis are used in Hach procedures. The 1,10- Phenanthroline Method is the best-known test for iron. The Fe2+ procedure uses Ferrous Iron Reagent Powder containing 1,10-Phenanthroline as an indicator. Total iron determination or analysis uses FerroVer Iron Reagent. FerroVer Iron Reagent contains 1,10-Phenanthroline, combined with a reducing agent, to convert all but the most resistant forms of iron present in the sample to Fe2+.