“…There are a wide variety of factors affecting the physical and chemical composition of such water: contact time with different rocks and soils, depth of the media, dissociation in aquifers, contact with the atmosphere and surface waters, etc. For most cases the main problem of groundwater is the high content of iron, hydrogen sulfide and free carbon dioxide (see [1], [2], [3], [4], [6], [7]). In our time there are a wide variety of water treatment methods, which can be grouped as follows: reagent-free; reagent; cation exchange; biochemical (see [3], [4], [5], [6], [12]).…”