Hard water has a high amount of calcium and magnesium carbonates and bicarbonates.
Hard water is water that hinders the development of foam when in contact with soap , because it has a high amount of bicarbonates and magnesium and calcium carbonates . To calculate the hardness of water, the concentrations of magnesium and calcium that are present in each liter of water are usually added.
It should be noted that water is a tasteless, odorless and colorless substance whose molecules are made up of two hydrogen atoms and one oxygen atom. It is an essential element for the development of life. Something hard , on the other hand, is not soft, exerts resistance or is rough.
The opposite of hard water is soft water : the liquid that has a very small amount of mineral salts. When there are no minerals in the water (that is, when it is made up only of hydrogen and oxygen), it is called distilled water .
Components of hard water
In addition to magnesium and calcium , the hardness of water is determined according to the amount of zinc , manganese or iron , among other cations (a cation is an ion whose electrical charge is positive, which means that it has suffered a loss of electrons; its oxidation state is positive).
According to the World Health Organization (WHO), this value should be expressed in milligrams of carbonate equivalent substances per liter of water; When it does not reach 60, then we are faced with soft water.
The hardness of water directly affects its organoleptic properties , that is, in all those parameters that we can use to describe its physical characteristics according to the perception that our senses have of them, among which are its texture , smell, flavor, temperature. and color.
Hard water can clog pipes and affect the operation of appliances such as irons and washing machines.
Classification according to type
Water hardness can be permanent or temporary. In the case of permanent hard water , no matter how much it is boiled, the chlorides and sulfates of magnesium and calcium are preserved since, after reaching a certain temperature , their solubility begins to decrease.
Temporary hard water , on the other hand, can lose its hardness when calcium hydroxide is added or when it is boiled. This is because their carbonates can dissolve and therefore be eliminated.
Effects of hard water
It is important to know that hard water causes various problems . When hard water is used in clothes irons, water heaters, washing machines and boilers, it is common for carbonates to become embedded in the tanks and pipes. In this way, the appliances can become clogged and stop working properly.
The WHO assures that water whose hardness exceeds 200 mg/l carries the risk of scale formation in tanks and pipes, while if it is below 100 mg/l, long-term corrosion may occur.
Regarding the impact that hard water can have on our health , the debate has not yet been closed, since to confront its detractors there are those who assure that its consumption is key to satisfying our body's need for magnesium and magnesium. calcium. Some researchers point out that both positions present inconsistencies and lack of accuracy, which is why it is important to approach the issue with an open mind and focus on the evidence before making a final decision.
There are experts who claim that in humans it can lead to the appearance of kidney stones, although none of the studies carried out specifically on this topic since 1984 have provided scientific evidence to support the risks that many attribute to hard water. The general trend, however, is to avoid its consumption by children and people with urinary problems.