One of the typical groundwater impurities, along with hydrogen sulfide and iron, is manganese. Most often it is masked by iron, which creates maximum discomfort when using water. The harm of manganese to humans was studied not so long ago. But the danger of manganese for health is much higher, as evidenced by its maximum permissible concentration of 0.05 mg/l for tap and bottled water and 0.5 for water from decentralized sources.
Where does the manganese in the water come from?
Like all other mineral components of natural waters, manganese compounds enter the water in the process of dissolving natural rocks. The content of manganese in the earth’s crust reaches about 0.1%.
In artesian water, it is predominantly found in the form of highly soluble bicarbonates and hydroxides, less often in the form of manganese sulfate. Manganese can usually be found in waters that contain iron. This is due to the fact that their chemical structure is close, and the minerals lie together.
Determination of manganese in water
Due to the rather low maximum permissible concentration (0.05 mg / l), it is impossible to visually detect the excess of manganese in water by several times with the naked eye. The probability of a rough estimate appears when its content is not less than 0.2 mg / l. Such indicators are not found in tap water samples, but are often characteristic of groundwater.
The presence of a very high content of this metal in underground water may be evidenced by the fact that some time after it is pumped out of the well, it acquires a gray tint, has a metallic taste and leaves a gray coating on plumbing. Manganese in well water is often masked by iron, which has a yellow-orange tint that is more intense at relatively high concentrations. Another indicator of the presence of manganese salts in water will be a specific shade of plaque on plumbing: if the iron has a characteristic orange (rusty) color, then if there is an additional high content of manganese in the water, the rust will have a reddish (and sometimes even burgundy) tint.
However, all the above mentioned points are only indirect signs and are extremely rarely able to clearly identify the problem. The most effective in such a situation would be instrumental chemical analysis, which should not be neglected due to the danger of this pollutant to humans.
Why is manganese dangerous in water?
Despite the fact that manganese is one of the important micronutrients that is involved in the synthesis of enzymes, its excessive intake in the body can lead to side effects.
The negative effect of this metal on the body has long been known, but most studies were based on its inhalation intake into the body, for example, in the process of arc welding.
The corresponding disease was called manganism; at the initial stages of the lesion, neurological symptoms are observed in the form of a decrease in the reaction rate, irritability, and compulsive behavior. In the later stages, the disease manifests itself with symptoms that are similar to Parkinson’s disease. Since the beginning of the 20th century, researchers have begun to identify the relationship of certain diseases with its concentrations in drinking water.
With regard to water and food, oral intake of this metal leads to the same effects as inhalation.
According to the reference book https://www.ncbi.nlm.nih.gov/books/NBK158868/ published by the American CDC, signs of poisoning are more pronounced in children. Systemic consumption of concentrations equal to or more than 0.2 mg / l for a long time (months, years) is fraught with mental problems, decreased intellectual abilities, aggressiveness, attention deficit hyperactivity disorder.
Another consequence of chronic manganese poisoning is reduced fertility in men. This sign is considered one of the very first indicators of poisoning, it develops earlier than other symptoms. Scientists have not yet found a direct link with female fertility.
Manganese is not a carcinogen and has practically no effect on other organs and systems.
Also, the question is often asked about if there is manganese in the water: is it possible to wash? The penetration of manganese through the skin is negligible, so bathing in such water is not dangerous.
Water purification from manganese
Fortunately, the solution to this problem is not difficult. If we talk about drinking water, then the best solution would be reverse osmosis filters, thanks to the membrane element, they ensure the complete removal of metals and other toxicants from the water, making it safe for adults and children.
As for water purification systems for the whole house, in this case, either bulk filters with catalytic loads or integrated water purification systems have the maximum efficiency.
Catalytic materials work on the principle of accelerated oxidation, when impurities are transferred to an insoluble state and settle in the granules of the bed. Such materials include Purolox, Birm, etc. Filters with Ecomix material are a solution for complex water purification from iron, manganese, hardness salts and natural organic substances. Thanks to the unique filling, they can combine all these functions in one body.