Calcium chloride groundwater

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... 

One of the minor occurrences of calcium chloride groundwater, but one where there has been a study on the source of the calcium chloride is in 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). 

Samarina, V. S., Ivanov, P. 1., and Martyanova, G. 1. (1971). Characteristics of Calcium Chloride Groundwater of Arid Regions and Principles of Its Distribution. Mono., Mater. GidrogeoL, Geol. Roli Podzem. Vod, 239-245. 

Among other articles on Israel s groundwater, the Bet Shean-Harod multiple calcium chloride aquifer system has been reviewed by Rosenthal (1988), and the similar Eocene aquifer of Alonim Shefara by Azmon (1993). Several articles have been written about calcium chloride in the coastal aquifer (Artzi et al, 1996 Vengosh et al, 1991), and about calcium chloride brine in the coastal sabkhas (playas Levy, 1977). 

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 wastes are injected into the lower part of the carbonate Floridan aquifer, which is extremely permeable and cavernous. The natural direction of groundwater flow is to the southeast. The confining layer is 45 m (150 ft) of dense carbonate rocks. The chloride concentration in the upper part of the injection zone is 1650 mg/L, increasing to 15,800 mg/L near the bottom of the formation.172 The sources used for this case study did not provide any data on the current injection zone. The native fluid was basically a sodium-chloride solution but also included significant quantities of sulfate (1500 mg/L), magnesium (625 mg/L), and calcium (477 mg/L). 

Rainwater Groundwater, lakes, rivers, seas, and oceans Carbon dioxide, nitrogen, oxygen, dust Sand (silica) and soil particles chlorides, bicarbonates, and sulfates, mainly of calcium, sodium, magnesium, and iron ions organic Air pollutants Rocks and soil, microorganisms, plant and animal... 

Water contains dissolved salts, dissociated into cations (positively charged ions) and anions (negatively charged ions). The most common dissolved cations are sodium (Na+), calcium (Ca2+), magnesium (Mg2+), and potassium (K+). The most common anions are chloride (Cl ), bicarbonate (11 CO,), and sulfate (SO4 ), discussed in section 5.5. The composition of groundwater, that is, the concentration of the different ions, varies over a wide range of values. 

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,... 

Freezing of waters in the active zone over winter results in the progressive concentration of the residual solution, until first carbonates, then sulfates and chlorides/nitrates precipitate out of solution. These salts can be scavenged by the first waters of the thaw, and these may also become concentrated solutions of chlorides/ nitrates and sulfates in the first instance. Thereafter, both secondary and primary carbonate can be scavenged, since, as Ca concentrations decline, the saturation index of calcium carbonate becomes negative. Hence, groundwaters in proglacial areas may span the spectrum from relatively... 

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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