Scavenging Ratios in an Urban Area in the Spanish Basque Country
Abstract:For a period of six years (1995–2000) the scavenging ratio, which is the ratio of a pollutant's concentration in water to its concentration in air, collected at an urban site in the Spanish Basque Country was studied. The aerosol is characterized by SO42− and NO3− with 1.79 and 1.61 μg m−3, respectively. Greater fractions of SO42−, NO3−, and NH4+ ions were present in the fine particle range, while greater fractions of other ions appeared in the coarse range. The most important species found in the precipitation is SO42− with 3.0 mg l−1. NO3−, Ca2+, and Cl− are the second most important ions. The volume-weighted mean concentration of H+ is 4.6 μg l−1 (pH = 5.3). The concentration of all analyzed ions (except H+) decreases throughout the rain event, showing the washout phenomenon of the rainwater. The scavenging ratio for the anthropogenic ions NO3−, SO42−, NH4+, and K+ is lower than the scavenging ratio for the marine-terrigenous ions, Cl−, Na+, and Ca2+.
Document Type: Research Article
Affiliations: Departamento de Física Aplicada II, Facultad Farmacia, Universidad País Vasco, Vitoria, Alava, Spain
Publication date: July 1, 2004