Carbon dioxide in soils

CASRN 127-20-8 molecular formula C3H3Cl2Na02 FW 164.95 Soil. Undergoes dechlorination and the liberation of carbon dioxide in soil. The residual activity is limited to approximately 3-4 months (Hartley and Kidd, 1987). The average half-life for dalapon-sodium in soil incubated in the laboratory under aerobic conditions was 15 d (Namdeo, 1972). 

The greater the amount of carbon dioxide in soil, the more hydronium ions and so the lower the pH. Soil that has a low pH is referred to as sour. (Recall from Chapter 10 that many acidic foods, such as lemon, are characteristically sour.) Two main sources of soil carbon dioxide are humus and plant roots. The humus releases carbon dioxide as it decays, and plant roots release carbon dioxide as a product of cellular respiration. A healthy soil may have enough carbon dioxide released from these processes to give a pH range from about 4 to 7- If the soil becomes too acidic, a weak base, such as calcium carbonate (known as lime or limestone), can be added. 

Lovell J. S. (2000) Oxygen and carbon dioxide in soil air. In Handbook of Exploration Geochemistry, Geochemical Remote Sensing of the Subsurface (ed. M. Hale). Elsevier, Amsterdam, vol. 7, pp. 451-469. 

Fig. 4-1. Relation between carbon dioxide in soil and copper mineralisation at Huaitongshan, Gansu province, China.

Oxygen and carbon dioxide in soil air SAMPLING AND ANALYTICAL METHODS... 

Fig. 14-5. Relation of carbon dioxide in soil air and geology at Balei gold veins, Baykal region, Russia (reproduced with permission from Kulikova, I960).

Fig. 14-7. Oxygen and carbon dioxide in soil air over the Filizchai pyrite deposit, Azerbaijan (reproduced with permission from Dadashev et al., 1971).

Fig. 14-11. Carbon dioxide in soil air (sample sites and contours in %) over mineralised breccia pipe, northern Arizona (from Lovell and Reid, 1989).

Hinkle, M.E., 1978. Helium, mercury, sulphur compounds and carbon dioxide in soil gases of the Puhimau thermal area, Hawaii Volcanoes National Park, Hawaii. US Geol. Survey, Open File Report, 78-246, 14 pp. 

Hinkle, M.E., 1990. Factors affecting concentrations of helium and carbon dioxide in soil gases. In Geochemistry of Gaseous Elements and Compounds. Theophrastus Publ., pp. 421 -448. 

Acid in the Environment Carbonic acid plays a key role in the formation of caves and of stalactites and stalagmites. Carbonic acid is formed when carbon dioxide in soil is dissolved in water. When this acidic solution comes in contact with calcium carbonate—or limestone rock—it can dissolve it, eventually carving out a cave in the rock. A similar process occurs when acid rain falls on statues and eats away at the stone, as shown in Figure 16. When this acidic solution drips from the ceiling of the cave, water evaporates and carbon dioxide becomes less soluble, forcing it out of solution. The solution becomes less acidic and the limestone becomes less soluble, causing it to come out of solution. These solids form stalactites and stalagmites. 

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