Carbon dioxide mineral waters
Among mineral waters, the group of carbon dioxide-rich waters is one of the most valuable. Carbon dioxide waters have an active effect on the human body both when used internally and externally. For internal use, the concentration of carbon dioxide must be not less than 0.5 g/dm³, and for external use—not less than 1.0 g/dm³.
The carbon dioxide that saturates underground mineral waters to the required concentration is mostly of volcanic and metamorphic origin. Water enrichment with carbon dioxide occurs during the process of intrusive thermometamorphism of rocks — thermal transformation of carbonate rocks caused by magma intrusion. These processes are typical for regions of recent and modern volcanism.
In Ukraine, the main area of modern carbon dioxide generation is Transcarpathia (Zakarpattia). Carbon dioxide ascends to the surface through zones of rock decompression. Beneath the Transcarpathian trough and the inner part of the Carpathian fold system, the magma chamber is relatively close to the surface, at a depth of about 20–30 km.
Carbon dioxide waters are characterized by a diverse anionic composition, with bicarbonates present in almost all such waters. The cationic composition is mainly represented by calcium or sodium. Mineralization varies widely—from fresh waters to brines.
Of the six types of carbon dioxide mineral waters explored in the former USSR, five types are found in Ukraine: the Narzan type (e.g., Svaliava and Shayan deposits), the Borjomi type (e.g., Polyana Kupel), the Essentuki type (e.g., Soymy deposit), the Julfa type (Hirske–Tysa deposit), and the Arzni type (Silsk deposit).
According to the classification of Academician V.M. Shestopalov, 25 types of carbon dioxide mineral waters are identified in Ukraine. Among them, 6 are single-component (pure carbon dioxide waters), 12 are two-component, and 7 are multi-component types. For example, two-component waters include carbon dioxide–boron waters (Holubynske deposit), carbon dioxide–siliceous waters (Shayan deposit), and carbon dioxide–iron-rich waters (Kelechyn deposit). Multi-component waters include carbon dioxide–boron–siliceous waters (Shayan‑2 deposit) and carbon dioxide–boron–strontium–iron waters (Soymy deposit).
It should be noted that in internal (drinking) use of carbon dioxide mineral waters, the ionic composition plays the most important role, while carbon dioxide enhances its physiological effect.
Indications for the use of carbon dioxide mineral waters include diseases of the digestive system—stomach, intestines, liver, pancreas, and biliary tract (outside the acute stage). Carbon dioxide baths have a positive effect on the cardiovascular system.
Based on carbon dioxide mineral waters, numerous health resorts have been established, such as “Polyana,” “Karpaty,” “Verkhovyna,” “Shayan,” and many others. At the same time, Ukraine has significant potential to expand and utilize hydro-mineral resources for the development of resorts and public health improvement.