Composition of rainwater in the central region of São Paulo City Composição iônica majoritária de águas de chuva no centro da cidade de São Paulo
Tipo
Artigo
Data de publicação
2004
Periódico
Quimica Nova
Citações (Scopus)
43
Autores
Leal T.F.M.
Fontenele A.P.G.
Pedrotti J.J.
Fornaro A.
Fontenele A.P.G.
Pedrotti J.J.
Fornaro A.
Orientador
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ISSN da Revista
Título de Volume
Membros da banca
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Resumo
The chemical composition of rainwater samples collected from March 2002 to February 2003 in downtown São Paulo city (Universidade Presbiteriana Mackenzie) is presented. Potentiometric and conductimetric measurements were used to evaluate the [H+] and the total ionic content. Major anions and cations were determined by ion chromatography with conductivity detection. The rainwater was acidic with a mean pH of 4.99. The volume weighted means, VWM, of the anions nitrate, acetate and sulfate were, respectively, 21.2, 16.9 and 12.4 μmol L-1. Ammonium was the most abundant ion with a VWM of 37.6 μmol L-1. The contribution of each anion to the free acidity potential decreases in the following order: SO42- (28.8%), CH3COO- (24.7%), NO3- (22.8%), Cl- (13.4%), HCOO- (7.7%) and C2O 42- (2.5%). The relative contribution of the weak organic acids to the free acidity was significant, 34.9%.