Size fractionated carbonaceous and iron oxides particles in urban environments in France and Senegal associated with intense emission sources.
- 1Laboratoire d'Aérologie, LAERO, Université de Toulouse, Toulouse, France, maria.dias-alves@aero.obs-mip.fr
- 2Géosciences Environnement Toulouse, GET, Université de Toulouse, Toulouse, France, loic.drigo@get.omp.eu
- 3OHMi Tessekere, ESS - Unité Mixte Internationale "Environnement Santé Sociétés", Université Cheikh Anta Diop de Dakar, Dakar, Sénégal, mayorog@gmail.com
- 4Centre De Microcaractérisation Raimond Castaing, Université de Toulouse, Toulouse, France, arnaud.proietti@ums-castaing.fr
- 5Centre Européen de Recherche et d'Enseignement de Géosciences de l'Environnement, CEREGE, Aix-Marseille Université, Aix-en-Provence, France, rochette@cerege.fr
- 6Instituto de Astronomia, Geofísica e Ciências Atmosféricas, Universidade de São Paulo, São Paulo, Brazil, andrea.ustra@iag.usp.br
Atmospheric aerosols in urban areas are the result of a complex mixture of different anthropogenic sources. The chemical and granulometric profile of urban aerosols varies according to the level of economic and technological development of cities around the world. In particular, road traffic emits carbon compounds (organic and elemental) and metal oxides through combustion, braking and tyre abrasion. Our study focuses on the respective particle size distributions of the carbon and iron oxide fractions using magnetic investigations.
We investigated the size distribution of anthropogenic tracers of particulate matter (PM), particulate total carbon (TC) concentration, and saturation isothermal remanent magnetization (SIRM) in two urban settings in France (Toulouse) and Senegal (Sebikotane). Using a cascade impactor, particles were segregated into 5 fractions spanning from PM10 to PM0.01. Particle mass concentration within each size range was determined via gravimetric methods, particulate carbon concentrations were assessed using thermo-optical techniques, and magnetic signals were measured through isothermal induced magnetization acquisitions.
Our results showed high concentrations of particulate mass in the coarse fraction (particles larger than 1 µm). The coarse fraction showed a significantly higher magnetic signal than for finer fractions, accounting for 73% in France and 80% in Senegal of the total SIRM. In the ultrafine fraction (<0.2 µm), we noted significantly higher concentrations of TC than for other fractions, representing 41% in France and 36% in Senegal of the total particulate carbon concentration.
Electron microscope observations revealed the presence of iron oxide particles in the <0.5 µm fraction however associated with a weak SIRM. Such iron particles may be produced by combustion or abrasion while we suspect that emissions by abrasion process produce larger particles.
How to cite: Delville, L., Léon, J.-F., Macouin, M., Tastevin, Y.-P., Gueye, M., Proietti, A., Laffont, L., Rousse, S., Dias-Alves, M., Demory, F., Rochette, P., Henrique da Silva Chibane, P., Teixera Ustra, A., and Drigo, L.: Size fractionated carbonaceous and iron oxides particles in urban environments in France and Senegal associated with intense emission sources., EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-14906, https://doi.org/10.5194/egusphere-egu24-14906, 2024.
