Quality -> Gas composition
All mineral waters, like all natural waters, consist in solution some quantities of gases. According to gas composition of underground waters, we can define conditions of water forming.
In underground waters gases come from atmosphere, during the mantle degasation, with chemical and biochemical processes in Earth crust.
Gases in underground waters are in solute and idle conditions. During the pressure decrement, solute gases traverse in idle. Solubility of gases in underground waters depends on temperature. With temperature increase, gases solubility reduces.
The most prevalent gases in underground waters are: oxygen (O2), carbon dioxide (CO2), hydrogen sulphide (H2S), hydrogen (H2), methane (CH4), hardly carbon hydrogen (ethane - C2H6, propane - C3H8, butane - C4H10), nitrogen (N2) and generous gases (helium - He and argon - Ar).
According to gas genesis, gases origin in natural waters can divide on four basic groups:
Gases of biochemical origin
They are forming in dissolution process of microorganisms, organic material and mineral salts. These gases are: CH4, CO2, hardly carbon hydrogen, N2, H2S, H2 and O2.
Gases of atmosphere originGases of chemical origin
They are coming in underground through the atmosphere. This group belong: N2, O2, Ar, He, Ne, Xe, Kr.
- Gases of metamorphic origin and they are forming as a result of agency of high temperatures and pressures on rocks. This group belong CO2, H2S, H2, CH4, CO, N2, HCl, NH3, B(OH)3, SO2, sulphide, Cl, S, etc.
- Gases of natural chemical reactions under the normal temperatures and pressures. In this group are CO2 and other gases.
Gases of radioactive origin
Rn, He, etc are gases of radioactive origin and they are emanating during radioactive decay.