اثر باران اسيدي بر تحرك ژئوشيميايي عناصر كلسيم، منيزيم و مس در خاك هاي منطقه سرچشمه، استان كرمان

Effects of Acid Rain on Geochemical Mobility of Ca, Mg and Cu in the Soils of Sar Cheshmeh Region, Kerman Province

Measurement of the acidity of precipitations in the years 2005 and 2006 indicates occurrence of acid rain in the region adjacent to the Sar Cheshmeh Copper Smelter at 155 km southwest of Kerman. This paper deals with the mobility, leaching and chemical change of three nutrient elements namely, Ca, Mg and Cu, by acid rains, from entisols and inceptisols of the Sar Cheshmeh region. Laboratory experiments were performed on 12 undisturbed soil core samples (50 cm tall, 6. 1 cm in diameter) with acid solutions of pH=3. l(as prediction of acute condition), pH=4.1(acid rain of studied area) and pH=5.6 (as natural rain). The sprinkling lasted 31 days, simulating a rainfall of 370mm, and the drainages were analyzed. Soil properties and forms of Ca, Mg and Cu in 0-15cm, 15-50cm and 30-50cm depths were determined before and after simulation. The investigations show that acid rain could mobilize and leach out some elements from soils of the studied area. Acid rain causes a decrease in the exchangeable form of calcium and magnesium, while soluble form of these nutrient elements increases. Furthermore, acid rain causes an increase in the available form of Cu. These changes could have negative and/or positive environmental effects on the Sar Cheshmeh area.