Manganese, ground-water compositions

In natural waters occur not one but several oxidation-reduction reactions. These reactions are associated with the presence of several elements, which are capable of changing their charge, and run in parallel. For this reason, total oxidation potential of the solution is defined by the nature and concentration of all redox-couples. Components which noticeably affect the solution s oxidation-reduction potential are called electroactive. Elements whose concentration and form of existence actually control solution s oxidation are culled potential-setting. In natural waters these are usually O, S, C, N and Fe. The medium whose oxidation potential value almost does not change with the addition of oxidizers or reducers is called redox-buffers. The redox-buffer may be associated with composition of the water itself, of its host rocks or with the effect of atmosphere. In the subsurface redox-buffers are associated, as a rule, with the content of iron, sulphur or manganese. Stably high Eh value in the surface and ground waters is caused by the inexhaustible source of in the atmosphere. 

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