Ocorrência de íons nas Precipitações Pluviais de Salvador-BA

Abstract

Rain water samples were systematically collected in the city of Salvador (Bahia) and its surroundings, between 1977 and 1978. From these samples the pH was determined and also the concentrations of Na⁺, Ca²⁺ , K⁺, Mg²⁺, Cl and NH₄⁺. Results are discussed as a function of the environmental conditions of the region, and ionic concentrations are used to estimate the possible interference of man-made sources in the chemical composition of rain water in this region. Mean weighted values in the four sampling points, varied between 1.22 and 5.85 mg Na⁺/ℓ, between 0.13 and 0.72 mg Mg²⁺/ℓ, 2.36 and 10.72 mg Cl^- /ℓ, 0.61 and 6.81 Mg Ca²⁺/ℓ, and 0.15 and 1.11 mg K⁺/ℓ. NH₄⁺ mean weighted values were similar in all sampling points. Generally the highest values were determined in the airport and the lower ones at Cabula, excepted for Ca²⁺ and K⁺ that presented higher concentrations at Aratu.