Caracterização química e morfológica de partículas sedimentadas na Região Metropolitana da Grande Vitória - ES
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Data
2013-06-27
Autores
Conti, Melina Moreira
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Universidade Federal do Espírito Santo
Resumo
The main objective of this thesis is to study the dustfall in the Metropolitan Region of the Great Vitória (RMGV),including an alysisordepositionflux, physico-chemical characterization, size distribution and morphologicalcharacterization to classifysource categories withhigh degree of similarityandcontributing to identifythe main sources of the region. The samples were collected between the months of May and November 2010 atfour sitesin RMGV, by using copper plates and samplers based on the American Standard ASTMD1739-98 (2004). The deposition flux was determinedby gravimetric methodbased on the Brazilian Standard ABNT MB3402 (1991). The analysis of the chemical composition andmorphology were performedby Scanning Electron Microscopy coupled with individual-particle X-ray analysis(SEM/EDS). Threemaingroups of particles were found:particles with high contentofSi and Al with low concentrations of K, Ti and Fe; particles with high content of C; and particles with highcontent ofFe.The first group is probably aluminum silicatematerials related to the crust and dirt roads. The second group the particles may have anorganic origin, related to biogenic processes, burning or coal handling. For the third group, the particlesareprobablyrelated to iron-ore processingand steel manufacturingin the region. It wasalso found a significant presence of NaCl particles, C-Caand high content of Ca-Mg. It was observed that more than 95% of the sampled setted the particles are smaller than 10 μm pelleted, however, more than 95% of deposited mass correspondsto particles larger than 10 μm.Regarding the determination of originof the particles, a comparisonbetween the results obtained here and previous CMB source apportionment study, performed by using CMB, indicates that the results obtained by both techniques are fairlyconsistent, but the use of SEM/EDSenables better source separation/identification, since it relies not only on chemical composition but also on morphological characteristics of the particles.
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Dustfall , SEM/EDX , Size distribution , Source apportionment , Fluxo de deposição , Partículas sedimentadas , MEV/EDS , Distribuição de tamanho , Identificação de fontes