Iron has been smelted and used for tools since the middle of the bronze age. In contrast to metals such as gold and silver, few ancient iron artefacts survive today due to its propensity to corrode. Iron became a major structural material during the industrial revolution. The first iron bridge, built in 1778, still stands today in the town that bears its name. Iron is the base metal of steel - the interaction of iron with alloying elements, primarily carbon, give steel unique properties. Steel's properties can be further enhanced with the addition of a number of alloying elements including: manganese, nickel, chromium, molybdenum, boron, titanium, vanadium, tungsten, cobalt and niobium.
By mass, iron is the most common element on earth, forming much of the Earth's crust and inner core. The average adult human body contains just 4 g of iron but it is essential for the production of haemoglobin, the oxygen carrying molecule of blood.
Since ancient times, it has been recognised that iron plays an important role in our health. The benefits of iron often go unnoticed until a person is not getting enough, deficiency in iron will lead to anaemia, a condition where your tissues and muscles do not get enough oxygen to work effectively. Iron is also an important element for an effective immune system, white blood cells require iron to proliferate and help the body fight infections.
The Recommended Dietary Allowance (RDA) for iron varies with age and gender, with women requiring roughly twice the amount as men. We derive approximately 95% of our iron from the food we eat with the remaining 5% coming from our drinking water.
Iron is not considered a serious contaminant of drinking water. Iron is abundant in minerals and the action of rainwater can leach iron into ground water sources. Iron, steel and galvanised steel are all common materials used in the manufacture of pipes for the distribution of water - corrosion of distribution pipes can increase the concentration of iron in our drinking water, particularly at lower pH. Although present in drinking water, iron is seldom found in concentrations greater than 10 ppm.
Iron in our water can be present in two states, namely ferrous and ferric. Water containing the soluble ferrous iron is clear and colourless but when exposed to air the iron can be converted to its insoluble ferric state. Iron in the ferric state is a rusty brown colour which can stain fixtures, fittings and laundry. Concentrations of ferric iron as low as 0.3 ppm can be problematic.
Iron in your drinking water can be detected by the following tests.
Iron can be reduced or removed from your drinking water using the following methods.
