| Title: | "Role of carbonyls and aromatics in the formation of tropospheric ozone in Rio de Janeiro, Brazil" |
| Author(s): | da Silva DB; Martins EM; Correa SM; |
| Address: | "Faculty of Engineering, Rio de Janeiro State University, Rio de Janeiro, Brazil. Faculty of Technology, Rio de Janeiro State University, Resende, Brazil. sergiomc@uerj.br" |
| DOI: | 10.1007/s10661-016-5278-3 |
| ISSN/ISBN: | 1573-2959 (Electronic) 0167-6369 (Linking) |
| Abstract: | "The ozone in Rio de Janeiro has been in violation of national air quality standards. Among all of the monitoring stations, the Bangu neighbourhood has the most violations of the national standard of 160 mug m(-3) for the years 2012 and 2013. This study evaluated the reactivity of the carbonyls and aromatics in the tropospheric ozone formation processes. The samples were collected between July and October of 2013. Carbonyls were sampled using SiO2 cartridges coated with C18 and impregnated with 2,4-dinitrophenylhydrazine and were analysed by HPLC. Activated carbon cartridges and GC/MS were used to measure the concentration of monoaromatic hydrocarbons. An air quality monitoring station provided the concentrations of the criteria pollutants and the meteorological parameters. Cluster analysis and a Pearson correlation matrix were used to determine the formation of groups and the correlation of the variables. The evaluation of the volatile organic compounds (VOC) reaction with OH radicals and the MIR scale was used to extrapolate the reactivity of VOCs to the ozone formation. The average concentrations obtained were 19.7 and 51.9 mug m(-3) for formaldehyde and acetaldehyde, respectively. The mean concentrations obtained for aromatics were 1.5, 6.7, 1.5, 2.6 and 1.6 mug m(-3) for benzene, toluene, ethyl benzene, m+p-xylene and o-xylene, respectively. The cluster analysis indicated the presence of three similar groups, with one formed by gaseous criteria pollutants, another formed by the meteorological parameters, ozone and fine particles, and the last group formed by the aromatics. For the two reactivity scales evaluated, acetaldehyde and toluene were the main ozone precursors" |
| Keywords: | "Air Pollutants/*analysis/chemistry Benzene/analysis Benzene Derivatives Brazil Environmental Monitoring Hydrocarbons/analysis *Models, Chemical Ozone/*analysis Silicon Dioxide/analysis Toluene/analysis Volatile Organic Compounds/analysis Xylenes Acetaldeh;" |
| Notes: | "Medlineda Silva, Debora Bonfim Neves Martins, Eduardo Monteiro Correa, Sergio Machado eng Research Support, Non-U.S. Gov't Netherlands 2016/04/16 Environ Monit Assess. 2016 May; 188(5):289. doi: 10.1007/s10661-016-5278-3. Epub 2016 Apr 14" |
