Why does drinking water contain sodium?

Sodium in drinking water - all the important information

What is sodium

Sodium is a common light metal. It is soft, shiny silver and highly reactive - therefore the element is always bound. Sodium compounds - the sodium salts - are found globally in the world's oceans, in rocks (feldspar) and in layers of deposits. Almost all of them are readily soluble in water. In addition to the sodium salts (halogens) there are chemical compounds with oxygen, sulfur and hydrides.
The mining and trading of salts has a long history. Cities like Salzburg and Salzgitter still bear witness to the economic importance of the “white gold”. Other place names (Halle, Bad Reichenhall, Hallstatt) go back to the root word Hall for saline.
In the English and French speaking countries, sodium is known as sodium. Other common names are soda or baking soda.
The most important sodium compound is sodium chloride - better known in households as table salt. Its extraction takes place on the one hand in seawater salines through evaporation. The salt content of the oceans fluctuates depending on the geological conditions.
The average is 35 grams per liter. The Baltic Sea has a low content of 0.2 to 2 percent, in the Dead Sea it is 28 percent. Another method is the extraction of salt from an underground brine (salt solution) by means of boiling. This creates evaporated salt. The construction of a graduation house, in which the concentrated salt is produced by evaporation of the brine, is complex. In central Germany's health spas (Bad Sulza, Bad Kösen, Bad Dürrenberg) you can admire impressive, historical graduation towers and use the salty ambient air to recover from lung diseases. The structure of the graduation tower and its underground saltworks is called the salt works.
Rock salt is mined on a large scale in deposits created by sedimentation.
The extracted sodium chloride is mainly used as table salt. Only a small part is processed into elemental sodium for industry, for example as a coolant and drying agent.
Other sodium compounds are sodium nitrate (sodium nitrate / Chiles nitrate), sodium sulfate or sodium peroxide. Sodium carbonate (soda) is a sodium salt of carbonic acid and, along with sodium chloride and sodium hydroxide, is one of the most relevant compounds.

How does sodium get into drinking water?

Sodium is a natural component of water. One hundred grams, i.e. 100 ml, of drinking water contain 4 mg of sodium.
Dissolved sodium gets into the groundwater from soils, rock layers and brine. Incoming seawater also plays a role near the coast.

How does sodium affect the human body?

Sodium is essential for the body. Along with calcium and potassium, it is one of the bulk elements in the body. Sodium, for example, is vital for the water balance, the acid-base balance, the electrical voltage of the cells and the transmission of stimuli in the nerves.
The German Nutrition Society recommends a daily intake of 1500mg for an adult. Other guidelines speak of a minimum of 300 or 550 milligrams. The WHO specifies a maximum intake of 2 grams per day.

Diet accounts for the largest share of sodium intake. Unfortunately, many industrially processed foods and especially fast foods contain an unnecessarily high amount of salt. Low-sodium foods are especially beneficial for the elderly. Since they usually do not take in enough fluids, they risk an excess of sodium with dangerous high blood pressure as a result. High sodium levels are also dangerous for babies because their kidneys are not yet able to excrete harmful substances as efficiently. Low-sodium water is therefore cheaper for young children.
The opposite - sodium deficiency - occurs in severe diarrheal diseases due to fluid loss.
For people with sweaty activities and athletes, there are special isotonic electrolyte drinks that are supposed to replenish lost minerals quickly. Mineral water that is particularly rich in sodium is, however, superfluous for the average consumer.
The sodium intake and the sodium excretion are interdependent.
Mineral water is considered to be low in sodium if it has a sodium concentration of less than 200 mg / l. Tap water is significantly lower at approx. 50 mg / l.
Conclusion: The exposure to high sodium drinking water is rather unlikely - excessive consumption of salted food is risky.

Drinking water polluted by sodium: what to do?

The limit value for sodium in the Drinking Water Ordinance 2001 is: 200 mg / l. It is noted there that geogenic excesses of up to 500mg / l are not taken into account.
Sodium in the form of table salt is a component of every waste water.
At the same time, various sodium compounds are used in wastewater treatment for reduction, neutralization, bleaching and precipitation.
Sodium sulphide is used to precipitate complex-bound heavy metals, sodium bisulphite reduces oxides.
In water softening by means of ion exchange, sodium reacts with the hardness components calcium and magnesium.

Have the sodium content tested

The municipal utilities guarantee top quality drinking water in accordance with the Drinking Water Ordinance 2001. Since the guideline value specified in the ordinance may be exceeded for geological reasons, the question arises as to the real numerical value. An important aspect for independent well operators. You can find out how high the sodium content of your tap water really is with a water test. Your own sampling is analyzed and clearly presented in a recognized laboratory. At the same time, you can find out other parameter values ​​(e.g. lead, nitrate, nitrite, iron, ammonium, phosphate, legionella) for your own drinking water.