Iron in drinking water

Iron in drinking water

 Iron (ferrum) is one of the most common chemical elements. In relation to other substances, about 5.1% Fe is present in the earth's crust, 12% in the mantle, 90% in the core. In terms of prevalence and quantity, the metal of the earth's interior is second only to aluminum. There are several forms of iron in nature. Iron of different valence is distinguished: Fe0, Fe + 2, Fe + 3 and complex chemical compounds, which include iron.

Where does the high iron content of drinking water come from?

 In the earth's crust, neoplasm processes continuously occur, in which ferrum (Fe, iron) takes part. Metal in an amount of 30-70% is contained in rocks - iron ores, from which it is mined for the needs of industry: During weathering, leaching, destruction of rocks, during the extraction of iron ore, together with thawed and poorly treated industrial effluents, iron enters the soil and water, which is used for drinking and technical needs. The cycle of iron in nature is due to iron bacteria, which oxidize ferrum to hydroxide (chemical compounds with water), then sediment in the form of bog ore. The consequences of excess iron in drinking water can be very different.

What form is iron in water

Fe forms over 300 different minerals, among them: chlorides, sulfides, nitrides. The compounds present in water are called salts. They can be in different states - be completely dissolved in a liquid, or stay in undissolved oxidized form (colloidal and suspended).

The water may contain:

Fe (II) - ferrous iron Fe (OH) 2;

Fe (III) -bivalent iron Fe (OH) 3;

Free Fe - suspended particles: FeCO3;

Fe in a complex form - dissolved or finely dispersed forms of FeOH +.

 The composition of ferrous compounds depends on the pH value, on the content of carbon dioxide, dissolved oxygen, hydrogen sulfide, on the presence of microorganisms capable of oxidizing and reducing iron. Regardless of what kind of impurities are in the water, it needs to be purified from iron to the parameters set by the standards.

What is the threat of drinking water with iron?

 Iron is present in the human body and all living organisms. Its permissible daily requirement is no more than 1-2 milligrams. With food and water, you need to get 10-18 mg, since no more than 10% is absorbed. For women and men, for children and adults, for people of different ages, iron norms are different.

 Up to 70% Fe is part of the iron-containing protein (hemoglobin), which is contained in erythrocytes. It participates in the respiratory and hematopoietic process - in the delivery of oxygen and blood to the tissues.

 An excess of iron provokes various diseases - hemochromatosis, which causes metabolic disorders, inflammation of the pancreas, and liver intoxication. The deficiency causes glandular anemia, cardiovascular problems, respiratory diseases.People have constant headaches, problems with memory and attention, loss of energy, fainting.

 A high concentration of iron in drinking water destroys hydraulic equipment - parts of boilers, machines, pipelines rust. Under the influence of water and air, the soluble (acidic) form of impurities changes to insoluble (oxide). 3-valent Fe precipitates, which, in contact with the surface of metal objects, forms rust. Corrosive deposits quickly destroy equipment, form blockages in pipes, deteriorating water quality. When heated, ferrum compounds actively react with water vapor, accelerating corrosion. Leaks appear, which is very dangerous for the heating system - you can burn yourself with steam and hot water.

Methods for the determination of iron in drinking water

The body is sensitive to an excess of iron in drinking water. The main signs are heart rhythm disturbances, skin pigmentation, yellow mucous membranes, signaling liver problems. If iron is exceeded in drinking water, the following are possible: dizziness, drowsiness, weakness, nausea. There is dryness, tightening of the skin when washing, brittle hair and nails.

Visual signs of an excess of large amounts of iron in drinking water:

  • Yellowish, brownish-reddish color.
  • Metallic smell.
  • Unpleasant metal taste.
  • Noticeable deposits on the sides and bottom of the dishes.
  • Rusty smudges on the plumbing.
  • Rust on valves.
  • Yellowing of light-colored laundry after washing.

 In water extracted from depth, impurities are in a dissolved form. Absolutely transparent water can flow from a well or from a water tap. After standing for a while in an open container, it changes color to brick-reddish. Cloudy flakes can float in it. Changes occur because iron in drinking water from a well is actively in contact with oxygen - it quickly oxidizes in air.

 If you suspect an increased iron content in drinking water, a laboratory analysis should be done. To get more accurate indicators of iron in drinking water, you need to check the readings every season throughout the year - in different natural periods, the water composition changes. You can analyze drinking water for iron in any accredited laboratory.

What to do when there is a lot of iron in drinking water

 If a lot of iron is found in drinking water, you need to choose the best water treatment options. Home methods of purifying drinking water with iron - boiling, settling, defrosting after freezing - are long, troublesome and not as effective. Even for domestic needs, it is convenient to use professional cleaning systems with filters for drinking water from iron:

  1. Deironing from aeration is a process in which dissolved gases are removed first. Then the bivalent ferrum is converted to trivalent and captured by the filter system. To restore the filtering ability, you do not need to use hazardous chemicals, the filter is simply washed with water. With the help of such filters, the norm for iron in drinking water is achieved.

  2. Ion exchange filtration - an active substance is used that removes negative ions from the water, due to which the drinking water is purified from iron and softened.

  3. Reverse osmosis - water molecules pass through the membrane, iron compounds and other impurities are captured. A household reverse osmosis filter is excellent for removing iron in drinking water.