Groundwater with calcium chloride

The environmental problems with calcium chloride in its deicing application, as with salt, are that when used in excess it can harm roadside vegetation and contaminate water supplies. Howard and Beck (1993) have studied the effect of road deicing chemicals upon the springs, wells, groundwater and aquifers near... 

The former Russian states have a large number of potash and halite deposits (Fig. 2.9), and calcium chloride brines have been associated with many of them. Sturua (1974) has presented a map of various Russian calcium chloride groundwater occurrences, and the majority of them are closely grouped near major potash deposits. In the Caspian Depression, Moskovskiy and Anisimov (1991) have reported such brines, and the Carpathian group s Stebnik potash deposit in south-central Russia (which contains potassium sulfate minerals, and not the normal sylvinite), still has dolomitization brine near the deposit (Valyashko et al, 1973). Similar brines have been found with 80-169 g/liter Ca in the Ukraine s Dnieper-Donets Basin, grading to 50, then 6 and finally 1.5 g/liter CaCl2 as the... 

The latter author tabulated many analyses of calcium chloride groundwater in various aquifers of the country (Fig. 2.31 and Table 2.12), with all of them appearing to be different forms of dolomitization brine. Those very near the coast (the first three of Israel 1 in Table 2.12) were almost pure seawater with much of the magnesium replaced by calcium, and very little of the sulfate yet precipitated. The other two samples of Israel 1 were from the central plateau, and of the same composition but considerably diluted with meteoric water. The oil field and Negev aquifers (Israel Oil and 2, 3) are slightly more concentrated seawater dolomitization brines, but the Rift Valley aquifers, springs and the Dead Sea represent considerably altered potash deposit dolomitization brine that appears to have traveled along the Red Sea fault system to Israel (Bentor, 1969). 

To construct the potential pH diagrams of the different elements, all their possible redox processes with water, oxygen, and hydrogen have to be taken into account, and the electrochemical potentials have to be calculated. In addition, the dissolution/precipitation equilibria (e.g., hydrolysis) have to be taken into consideration, as well. The main dissolved ions in groundwater (calcium, magnesium, sodium, and potassium cations hydrocarbonate/carbonate, chloride,... 

Dissolution of feldspars is a logical source of dissolved silica, calcium, sodium, and potassium in groundwater. Similarly, the reaction of carbon dioxide-charged water with silicate minerals is a logical source of bicarbonate. Rogers (1987) examined these and other hypotheses using a mass-balance approach. In these calculations, chloride and sulfate were not considered, and the beginning concentrations were considered to be... 

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