Iron
What is Iron?
A very common element often present in groundwater in amounts ranging from 0.01 to 10.0 ppm (mg/L). Iron may be found in three forms: In soluble form such as in ferrous bicarbonate; in solid form bound with a soluble organic compound; or as suspended ferric iron particles.
The Effects of Iron in your Water
Iron above 0.3 mg/L is objectionable in water because of staining in laundry and plumbing fixtures caused by the oxidation and precipitation of ferric hydroxide and/or ferric oxide (ferric iron) into small solid iron particles. Iron can also give a metallic or distorted flavor to beverages.
A water conditioner system will effectively remove iron deposits from your water.
Types of Iron
• Ferric Iron
• Ferrous Iron
What is Ferric Iron?
Small solid iron particles containing trivalent iron, usually as gelatinous ferric hydroxide [Fe(OH)3] or ferric oxide (Fe2O3), which are suspended in water and often rusty water. Ferric Iron is also called precipitated iron.
Ferric iron is sometimes known as red water iron because of its rusty red appearance when drawn. It is actually clear water iron, which has been oxidized, usually from dissolved oxygen or other factors in the water. This type of iron is not dissolved in the water but rather is suspended in solution
The Effects of Iron in your Water
Ferric iron can also be formed from ferrous iron simply by letting it stand for a while. This sometimes can be witnessed in toilet bowls. Homeowners are sometimes surprised to find that upon returning from vacation, the water in their toilets has turned color. This somewhat unpleasant example shows a transformation from ferrous to ferric iron due the addition of oxygen from the air.
The same transformation can be witnessed at sinks or bathtubs with drippy faucets. Clear water drips from the faucets, but after remaining a while on the surface of the sink or tub the water turns red or yellow indicating the presence of iron. Once again, ferrous iron has changed to ferric iron by the addition of oxygen from the air.
Even though particles of ferric iron are suspended in the water, there is still a big problem when trying to remove them with simple filtration. The iron particles will rapidly clog filters causing low flow rates and making frequent filter changes necessary. Additionally, ferric iron is almost always accompanied by ferrous iron, which will simply slip through the filter causing staining when it is finally exposed to oxygen from the air.
What is Ferrous Iron?
A divalent iron ion, usually as ferrous bicarbonate [Fe (HCO3)2] which, when dissolved in water, produces a clear solution. Ferrous Iron is also called clear water iron.
The Effects of Iron in your Water
Ferrous Iron has not yet been exposed to oxygen and therefore has not “rusted” or oxidized. This iron is totally dissolved in water. This clear iron can easily pass through standard home store sediment filters, thwarting the best efforts of homeowners, then later change to a staining color on the surface of sinks, toilets or showers where air oxidizes it.
No amount of sediment filters or even carbon filters can stop this type of iron. The clear iron simply passes right through the filter. After time, the water remaining in the filter does itself oxidize, clogging the filter, dramatically reducing the water flow rate, forcing the homeowner to continuously replace the filter inserts.