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| Titel |
Characteristics of the nanoparticles in soot aggregates from Barcelona (Spain) during DAURE winter campaign: the closure of a complex state of mixture |
| VerfasserIn |
Esther Coz, Gary S. Casuccio, Traci Lersch, Begoña Artíñano |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250049500
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| Zusammenfassung |
| Nano-sized heavy metal compounds and mineral dust are frequently found as part of the
structures in larger anthropogenic particles from urban environments (Adachi and Buseck,
2010). The study of these particles has received special attention in recent studies due to
harmful toxicological and environmental effects. For instance, the heavy metal particles from
combustion engine exhaust are associated to smaller sizes than the aggregate’s monomer,
falling within the range of maximum alveoli deposition able to entering into the
blood circulation (Mayer et al., 2010). PM2.5samples were collected for electron
microscopy analyses during an atmospheric episode of thermal inversion in February
2009 in an urban background area within the city of Barcelona. This sampling
was performed in the framework of a larger campaign DAURE (Determination
of the sources of atmospheric Aerosols in Urban and Rural Environments in the
western Mediterranean). The main goal of this part of the study was to quantify the
characteristics of the nanoparticles hosted in the urban soot structures in the city
during the winter DAURE campaign. Elemental composition and morphological
parameters of several thousand particles were obtained by electron microscopy
means.
Ultrafine silicates and metal particles were both abundant inside the soot structure of the
urban samples, frequently coated by organic/inorganic layers. Silicates were found in nearly
50% of the soot particles. Nearly 65% of the Si-bearing particles were associated also to
heavy metal compounds. In Barcelona, the presence of metal nanoparticles was quite variable
from sample to sample, with percentages between 25% and 91%, associated to slightly
smaller sizes to those of the monomers (Adachi and Buseck, 2010) and to higher
concentrations during traffic peak hours. In average, the metal nanoparticles were present in
60±19% of the soot structures, a similar number to that found for the Mexico City study by
Adachi and Buseck (2010). However, the composition and variety of these particles
were far from similar in both studies. Fe, Cu and Pb were less abundant inside
the soot nanostructures from Barcelona suggesting a link to different sources than
those from Mexico City. Metal nanoparticles in soot were V, Cr, Ni, Ba, and Zn
enriched. The abundance of these nanometals seems the closure of a complex coating
structure comprised by mixtures of both nitrate and organic compounds (Coz et al.,
2010).
References
Adachi, K. and Buseck, P. R. (2010). Hosted and Free-Floating Metal-Bearing
Atmospheric Nanoparticles in Mexico City. Environmental Science & Technology
44:2299-2304.
Mayer, A. C., Ulrich, A., Czerwinski, J. and Mooney, J. J. (2010). Metal-Oxide
Particles in Combustion Engine Exhaust. SAE 2010 World Congress & Exhibition
SP-2289:2010-2001-0792.
Coz, E., Casuccio, G.S., Robinson, A.L., Moreno, T., Mohr, C., Prevot, A.S.H., Artíñano,
B. (2010). Structural characteristics of internally mixed carbonaceous aggregates from
Barcelona (Spain) during DAURE winter campaign. EGU General Assembly 2010, 2-7 May,
2010 in Vienna, Austria, p.13923.
Acknowledgements
The authors acknowledge the coordination of the campaign to Andrés Alastuey,
Xavier Querol and Jose Luis Jimenez. This part of the study has been financed by the
CGL2007-30502-E/CLI, CGL2008-02817-E/CLI, PROFASE (CGL2007-64117) and
GRACCIE (CSD2007-00067) projects. |
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