Chemical characterization and origin of suspended atmospheric particles in Meknes city in Morocco
Résumé
This work is a study of elemental composition of particulate matter (PM-10, with aerodynamic diameter lower or equalizes to 10 mu m, collected in Meknes city in Morocco. The campaigns of measure carried out on a traffic site from March 2007 to April 2008. The chemical concentrations of 9 elements (Ca, Cr, Cu, Fe, K, Mn, Ni, Pb and Zn) were determined by Total reflection X-Ray Fluorescence (TXRF), Al was determined by the Atomic Absorption Spectrometry (AAS), whereas the Pb isotopic compositions were determined by Thermo Ionisation Mass Spectrometry (TIMS). The obtained results show quite significant seasonal variation of the chemical composition for fine and coarse fractions. It should be noted that Pb and Ni concentrations exceeded the air quality standards. The calculation of the Enrichment Factor (EE) revealed that Cr and Pb were attributed mainly to anthropogenic sources. The use of the isotopic extraction of lead confirms the anthropic origin of Pb.