Mersin`de yağmur suyunun temel iyonik bileşimi - asit yağmurları

Abstract

MAJOR IONIC COMPOSITION OF RAINWATER IN MERSIN -ACID RAINSPELIN TURKERABSTRACTThe chemical composition of precipitation in the city of Mersin on the Mediterraneancoast of Turkey has been studied. Spatial and temporal variability of rainwater constituentshave been determined from samples collected at two central and two suburban stations for oneyear period between December 2003-January 2005. A total of 157 samples covering allprecipitation events were analyzed to determine pH, conductivity, as well as major anion(ClÃ, NO3 Ã, SO4 2à and major cation (H+, Na+, K+, Ca2+, Mg2+, NH4 +) concentrations.The pH varied in a wide range of 4.8-8.5 and the volume-weighted mean was found6.79. Only 8 out of 157 samples in the acidic range (pH < 5.6). The remaining highlyalkaline samples being neutralized by either NH4 + in rainwater or CaCO3 resulting from wetdeposition of atmospheric dust.The concentration of major ionic species has the following order: Ca2+ > SO4 2Ã!ClÃ!1+ + > Na+ > Mg2+ > NO3 2à is observed to beà ! . ! + 7KH PHDQ 62higher than NO3 -. The relative contributions of sulfate and nitrate ions to the acidity ofMersin precipitation were found to be 71 % and 29 %, respectively. Comparison of theanthropogenic sulfate and nitrate concentrations with the literature data suggest that Mersinatmosphere is not heavily loaded by these ions and there is not serious air pollution problemwithin the city. Relatively higher NH4 +, NO3 - and SO4 2à concentrations measured nearthe center of Mersin suggest increased pollution from local anthropogenic sources, e.g.,residential heating, industrial and/or traffic emissions.Key Words: Eastern Mediterranean, Mersin, Major ions, Acid rain, Alkaline rains.