Manganese is hard metal silvery-white colour and belongs to VIIb group of Periodic table of the elements. Manganese is one of the most frequent metals in Earth crust and it occurs together with iron. The most frequent minerals of manganese are oxides, silicates and carbonates. It is important ingredient of alloys and it is using in chemical industry. Also it is using in production of iron and steals and as oxidant at cleaning, bleach and disinfection as KMnO4 and like ingredient of different products. In latest time, manganese is using in organic compounds for increasing of octane number at petrol. Manganese green sand sometimes uses for water treatment.
Origin in water
Manganese occurs naturally in many surface waters and in springs of underground water, especially in anaerobic or low oxidation conditions and that is the most important source for drinking water. Manganese concentration in water is smaller then iron concentration. Expected average value is about 0, 06 mg/1. When the manganese concentration is above 1mg/l, then the manganese minerals come to contact with water under the reduction conditions or under the bacteria activity.
There is manganese in all cells in organism, and mostly in organs which cells are rich mitochondria (liver, pancreas and kidney). Manganese is essential element for people and animals. It has important part in calcium and phosphor metabolism, as in conservation of reproductive organs.
Manganese has part of coenzyme and activates many enzymes. It helps synthesis of haemoglobin. It is important for thyroxin (hormone of thyroidal gland) making. It helps production of carbon hydrates and fats. Manganese is important in prevention of osteoporosis. It betters mind and remits nerve irritability.
Manganese causes neurological effect during inhalation, especially at individually profession. High concentration of manganese is dust or vapour and long inhalation are necessary to cause chronic poising manganese (effect similar to Parkinson disease) (De Zuane, 1997). There are epidemiologic studies in which neurological effect investigate during long exposure to big manganese concentration in water (accidence of respiratory system and central nerve system, and changes on skin). Meanwhile, there are many important, potential confusing factors in that study, and many other studies do not achieve to notice bad effects with drinking water.
Maximal allowable concentrations
According to recommendations of EU (Directive 98/83/EC) limitary value for manganese is 50 fj.g/1. The same value is in our rules for drinking water (Sl. list SRJ 42/98).