The Influence of a Coal-Fired Power Plant in Turkey on the Chemical Composition of Rain Water in a Certain Region

摘要

In this study, the chemical composition of the rainwater in Yatagan, which is a region surrounding a coal power plant was investigated from February to April 2002. Rainwater samples were obtained from Yatagan, located northwest of Mugla City in Turkey. pH values and concentrations of major ions (Ca~(2+), Na~+, K~+, SO_4~(2-), NO_3~-, NH_4~+) in the rainwater samples were analyzed. The pH varied from 5.1 to 7.9 with an average of 6.7 which was in alkaline range considering 5.6 as the neutral pH of cloud water in equilibrium with atmospheric CO_2. In the total of 30 rain events, only three events were observed with water in the acidic range ( < 5.6), which occurred after continuous rains. The equivalent concentration of components followed the order: Ca~(2+) > SO_4~(2-) > Na~+ > NH_4~+ > NO_3~- > K~+ > H~+. The anion and cation concentrations in the rainwater samples showed a high sulphate concentration (131 μEq/l), as well as high sodium (40 μEq/l) and calcium (298 μEq/l) concentrations. These values indicate that one probable source of the high sodium concentration is fly ash, after the coal burning process and the power plant can be effective on level SO_4~(2-) concentrations in rainwater. In addition, the dust-rich local and surrounding limestone environment might have caused the high concentration of Ca~(2+) in rainwater of the Yatagan Basin. Due to a large contribution of these cations to the sulphate neutralization action, the rainwater of this region displays only a moderate acidity, which does not cause significant environmental impact.