Chemical composition of rainwater collected at two sampling sites in the city of Rijeka.

This study compares the chemical composition of rainwater samples collected at two sampling sites, the first situated in the Rijeka city centre and the second in a suburban site 120 m above the sea level. The rainwater samples were analysed for precipitation weighted average concentrations of hydrogen, sulphate, nitrate, chloride, ammonium, sodium, potassium, calcium, and magnesium. The results suggest that the local washout of the atmosphere enhanced the rainwater acidity in the city centre which also received significant marine contributions of sulphate, calcium, magnesium, and potassium content. Rainwater in the suburban site was affected by soil dust and/or fertilizers used in the nearby gardens, resulting in partial neutralization with rising of pH value. While the content of S-SO4 was practically equal at both sites, the quantities of N-NO3 and N-NH4 nearly doubled at the suburban site.