In this diploma thesis there was studied a composition of a solid fraction of the atmospheric aerosol of the daily measurements from Pilsen by X-ray powder diffraction by the method of the parallel beam. The phase analysis was accomplished by comparing of the diffraction dates with a database of compounds usually occurring in the solid fraction of the atmospheric aerosol in this area. This database was created from works published earlier. In these samples there were also identified asbestos fibers of actinolite by the scanning electron microscope with EDS module. In this thesis there was also described a transport of several anthropogenic compounds of the atmospheric aerosol in dependence on a meteorological situation. Powered by TCPDF (www.tcpdf.org)

En cas de rejets de polluants ou de radionucléides dans l’atmosphère, l’estimation du lessivage des particules d’aérosol atmosphérique par les précipitations est une donnée essentielle pour évaluer la contamination de la biosphère. De nombreuses études se sont déjà intéressées à ce processus de dépôt humide, mais la plupart d’entre elles sont d’ordre théoriques ou ont été menées en laboratoire. Cette étude a donc pour objectif d’améliorer la connaissance du potentiel de lessivage des particules d’aérosol par les précipitations par une approche expérimentale en conditions in situ. Durant plusieurs mois, trois sites aux environnements distincts en termes de climatologie et d’empoussièrement ambiant ont été instrumentés pour disposer d’une palette de situations précipitations/empoussièrement la plus variée possible. Un disdromètre laser et un granulomètre (compteur électrique et/ou optique) ont mesurés respectivement les caractéristiques des précipitations et les concentrations de particules à une résolution temporelle élevée et sur une large gamme de diamètre. L’utilisation de ce couplage instrumental original a permis de déterminer les potentiels de lessivage pour des particules de la gamme nanométrique à supermicronique et pour différents types de précipitations (chutes de neige et pluies avec des hyétogrammes spécifiques). Dans un premier temps, le coefficient de lessivage ᴧ (paramètre décrivant la cinétique du processus) a été calculé en considérant l’effet global d’une précipitation. Cette approche « macroscopique » est limitée par l’influence de processus « concurrents », tels que l’advection ou les sources d’émissions de particules à proximité des sites de mesures. Pour minimiser l’impact de ces processus sur nos résultats, une seconde méthodologie basée sur la résolution temporelle élevée de l’instrumentation utilisée a été définie. Par cette approche « intra-évènementielle », les coefficients de lessivage ᴧ sont calculés sur de courtes périodes de temps, permettant ainsi d’étudier l’influence de la variabilité du diamètre des particules et des caractéristiques des précipitations sur ces coefficients. Les résultats obtenus par les deux types d’approches ont mis en évidence la nécessité de prendre en compte le diamètre des particules et les caractéristiques des précipitations pour modéliser fidèlement le lessivage des particules d’aérosol atmosphérique. En comparant les résultats des deux types de précipitations, la prédominance du lessivage par des chutes de neige par rapport au lessivage par la pluie a été illustrée. L’importance du diamètre des particules lessivées a été démontrée. Entre le mode « ultrafin » et le mode « grossiers », la variation du coefficient de lessivage est d’un ordre de grandeur (entre environ 2.10¯³et 2.10¯⁴ s¯¹). Le potentiel de lessivage minimum est obtenu pour des particules d’environ 100 nm, ce qui est cohérent avec la théorie du « Greenfield gap » (entre 0,1 et 1 µm). Pour les besoins de la modélisation, une paramétrisation robuste entre le coefficient de lessivage ᴧ et le diamètre des particules d’aérosol (de 10 nm à 10 µm) a été établie. Différentes relations entre le coefficient ᴧ et l’intensité pluviométrique sont proposées aussi pour différentes gammes de diamètre de particules et comparées notamment aux valeurs implémentées actuellement dans le modèle ldX utilisé à l’Institut de Radioprotection et de Sûreté Nucléaire. / In case of release of pollutant or radionuclides into the atmosphere, estimate of below-cloud scavenging of aerosol particles by precipitation (or washout) is an essential data to evaluate contamination of the biosphere. Many studies have already shown an interest to this wet deposition process, but most of them are theoretical or have been conducted in laboratories conditions. This study in situ conditions aims to improve knowledge of below-cloud scavenging of aerosol particles by precipitation. For several months, three sites with separate environments in terms of climate and ambient dust have been instrumented to have such a varied palette of precipitation/dust conditions as possible. A laser disdrometer and a granulomètre (electrical and/or optical counter) measure respectively precipitations characteristics and particles concentrations with a high temporal resolution (one minute). The use of this original instrumental coupling has allowed determining washout potentials for the nanometric size range of particles aerosol to the supermicronique size range and for different types of precipitation (snowfalls and rainfalls with specifics hyetograms).Initially, below-cloud scavenging coefficients ᴧ (parameter describing kinetic of this process) were calculated considering the gobal effet of a precipitation. This “macroscopic” approach is limited by the influence of “concurrent” processes, as advection or local emissions of aerosol particles close to the measurements sites. To minimise effect of these processes on our results, a second methodology based on the high temporal resolution of the instrumentation used was defined. With this “intra-event” approach, washout coefficients are calculated on short time scales, allowing study of impact of the variability of aerosol size and precipitations characteristics on these coefficients.Results obtained with the two approaches highlighted the need of considering particles diameter and characteristics of precipitation to model accurately below-cloud scavenging of aerosol particles. Comparing results for both type of precipitation, predomination of below-cloud scavenging by snowfalls compared with below-cloud scavenging by rainfalls was shown. The importance of the scavenged aerosol diameter was demonstrated. From the “ultrafine” size range to coarse mode of particles, below-cloud scavenging coefficient varies by an order of magnitude (from 2.10¯³ to 2.10¯⁴ s¯¹). Minimum potential is obtained for particles of about 100 nm, which is consistent with theory of “Greenfield gap” (from 0.1 to 1 µm). For modeling needs, a robust parametrization between washout coefficient ᴧ and aerosol particles diameter (from 10 nm to 10 µm) has been established. Also some relationships between coefficient ᴧ and rainfall intensity are proposed for different particles size range and compared in particular with values implemented in model ldX currently used at the French Institute of Radioprotection and Nuclear Safety.

Neste trabalho foram estudadas as influências sazonais sobre as concentrações de hidrocarbonetos policíclicos aromáticos e n-alcanos no material particulado MP10, em novembro de 2001 a junho de 2002 (n = 23), e entre abril de 2003 e maio de 2004 (n=31), em continuidade aos estudos realizados no inverno de 2000 na RMSP. Todas as coletas do aerossol atmosférico ocorreram no Instituto de Astronomia, Geofísica e Ciências Atmosféricas da USP, situado na Cidade Universitária, na região oeste da cidade de São Paulo. Os parâmetros meteorológicos como temperatura, precipitação, umidade relativa, direção e velocidade do vento foram monitorados. Em média, nas estações mais frias foram obtidas as maiores concentrações de MP10, HPA e n-alcanos, em concordância com outros estudos. Os dados foram tratados com algumas ferramentas estatísticas, como análise de componentes principais e estudos das razões diagnósticas, sugerindo algumas fontes de emissões e apontando a emissão veicular como fonte majoritária destes poluentes atmosféricos. / The seasonal influences on the concentrations of polycyclic aromatic hydrocarbons (PAH) and n-alkanes in the particulate matter PM10 were studied in this work from November 2001 to June 2002 (n = 23), and between April 2003 and May 2004 (n=31), in continuity to the studies accomplished in the winter of 2000 in the metropolitan area of São Paulo (MASP). Atmospheric aerosol samples in this work were collected in an open area on the roof of the Department of Atmospheric Sciences of USP, located in the campus in the University of São Paulo, in the west area of the city of São Paulo. The meteorological parameters, as temperature, precipitation, relative humidity, direction and wind speed were monitored. On average, in the coldest stations they were obtained the largest concentrations of PM10, PAH and n-alkanes, in agreement with other studies. The data were treated with statistical tools such as Principal Component Analysis and studies of the diagnostic ratios, suggesting some sources of emissions and pointing the vehicular emission as majority source of these pollutant ones in the atmospheric.

Neste trabalho foram estudadas as influências sazonais sobre as concentrações de hidrocarbonetos policíclicos aromáticos e n-alcanos no material particulado MP10, em novembro de 2001 a junho de 2002 (n = 23), e entre abril de 2003 e maio de 2004 (n=31), em continuidade aos estudos realizados no inverno de 2000 na RMSP. Todas as coletas do aerossol atmosférico ocorreram no Instituto de Astronomia, Geofísica e Ciências Atmosféricas da USP, situado na Cidade Universitária, na região oeste da cidade de São Paulo. Os parâmetros meteorológicos como temperatura, precipitação, umidade relativa, direção e velocidade do vento foram monitorados. Em média, nas estações mais frias foram obtidas as maiores concentrações de MP10, HPA e n-alcanos, em concordância com outros estudos. Os dados foram tratados com algumas ferramentas estatísticas, como análise de componentes principais e estudos das razões diagnósticas, sugerindo algumas fontes de emissões e apontando a emissão veicular como fonte majoritária destes poluentes atmosféricos. / The seasonal influences on the concentrations of polycyclic aromatic hydrocarbons (PAH) and n-alkanes in the particulate matter PM10 were studied in this work from November 2001 to June 2002 (n = 23), and between April 2003 and May 2004 (n=31), in continuity to the studies accomplished in the winter of 2000 in the metropolitan area of São Paulo (MASP). Atmospheric aerosol samples in this work were collected in an open area on the roof of the Department of Atmospheric Sciences of USP, located in the campus in the University of São Paulo, in the west area of the city of São Paulo. The meteorological parameters, as temperature, precipitation, relative humidity, direction and wind speed were monitored. On average, in the coldest stations they were obtained the largest concentrations of PM10, PAH and n-alkanes, in agreement with other studies. The data were treated with statistical tools such as Principal Component Analysis and studies of the diagnostic ratios, suggesting some sources of emissions and pointing the vehicular emission as majority source of these pollutant ones in the atmospheric.

<p>  </p> <p>Secondary organic aerosols (SOA) play an important role in the Earth’s radiative budget due to their potential to either warm or cool the atmosphere through light absorption or light scattering, respectively, and to cool or warm the lower atmosphere by acting as cloud condensation nuclei. SOA are air-suspended liquid and semi-solid droplets that form through multiphase chemical processes. Atmospheric photochemical oxidation of volatile organic compounds (VOCs) in the presence of air pollutants, such as NO_x (NO + NO₂) and the OH radical, promote formation of low volatility organic products that eventually condense to form SOA. To better understand the sources and sinks, formation, and fate of SOA, laboratory studies investigating oxidation of a biogenic VOC as well as anthropogenic emissions of SOA precursors were conducted. The first study (<em>Chapter 3</em>) investigated the OH-initiated oxidation of β-ocimene, a biogenic volatile organic compound (BVOC) released from vegetation, including forests, agricultural landscapes, and grasslands emitted during the daytime. The oxidation of BVOCs in the presence of NO_x leads to the formation of functionalized organic nitrate (RONO₂) compounds and isomers that easily condense to form SOA. To understand their atmospheric fate, the RONO₂ hydrolysis rate constants were quantified and found to be highly pH dependent. The findings of this study provide key insights into the formation and fate of organic nitrates and NO_x cycling in forested environments from daytime monoterpenes that were not previously included in atmospheric models. </p> <p>The second study (<em>Chapters 4 and 5</em>) investigated condensed waste emissions generated during Cured-In-Place-Pipe (CIPP) installations. This installation process is the most popular, least expensive, and most frequently used technology that cures leaking sanitary and stormwater sewers. Waste plumes discharged during pipe manufacture are complex multi-phase mixtures of volatile and semi-volatile organic compounds (VOC and SVOC, respectively), primary organic aerosols and SOA, fine debris of partially cured resin, and direct emission of nanoplastic particles that are all blown into the atmospheric environment at significant concentrations at worksites. This work unveiled a direct emission source of airborne nanoplastic particles as well as substantial concentrations of hazardous compounds and SOA precursors that were previously unrecognized. </p>

Atmospheric haze, which builds up over South Africa including our study areas, Cape Town and the Mpumalanga Highveld under calm weather conditions, causes public concern. The scope of this study was to determine the concentration and composition of atmospheric aerosol at Khayelitsha (an urban site in the Western Cape) and Ferrobank (an industrial site in Witbank, Mpumalanga). Particulate matter was collected in Khayelitsha from 18 May 2007 to 20 July 2007 (i.e. 20 samples) using a Partisol-plus sampler and a Tapered Element Oscillating Microbalance (TEOM) sampler. Sampling took place at Ferrobank from 07 February 2008 to 11 March 2008 (6 samples) using a Partisol-plus sampler and an E-sampler. The gravimetric mass of each exposed sample was determined from pre- and post-sampling weighing. The elemental composition of the particulate matter was determined for 16 elements at Khayelitsha using Proton Induced X-ray Emission (PIXE). The concentration of the elements Al, Si, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Cu, Zn, As, Br, Sn, and Pb was determined by analysing the PIXE spectra obtained. In similar manner, the elemental composition of the particulate matter was determined for 15 elements at Ferrobank (Al, Si, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Cu, Zn, As, Br and Pb). The average aerosol mass concentrations for different days at the Khayelitsha site were found to vary between 8.5 μg/m3 and 124.38 μg/m3. At the Khayelitsha site on three occasions during the sampling campaign the average aerosol mass concentrations exceeded the current South African air quality standard of 75 μg/m3 over 24 h. At the Ferrobank site, there are no single days that exceeded the limit of the South African air quality standard during the sampling campaign. Enrichment factors for each element of the particles sampled with an aerodynamic diameter of less than 10 μm (PM10) samples have been calculated in order to identify their possible sources. The analysis yielded five potential sources of PM10 : soil dust, sea salt, gasoline emissions, domestic wood and coal combustion. Interestingly, enrichment factor values for the Khayelitsha samples show that sea salt constitutes a major source of emissions, while Ferrobank samples, the source apportionment by unique ratios (SPUR) indicate soil dust and coal emission are the major sources of pollution. The source apportionment at Khayelitsha shows that sea salt and biomass burning are major source of air pollution.

Neste trabalho aplicamos três modelos: receptor, de equilíbrio químico e de dispersão, para a identificação de fontes da Matéria Particulada Inalável do aerossol atmosférico de São Paulo. Utilizamos dados de dois experimentos realizados no campus da USP em São Paulo. ° experimento realizado em 1986 teve como local de amostragem o Instituto de Física, enquanto o experimento de 1989 foi realizado no Instituto de Química como parte do SPACEX (São Paulo Atmosphere Characterization Experiment). As amostras de Matéria Particulada Fina (MPF) e Matéria Particulada Grossa (MPG) foram submetidas à análise gravimétrica e à análise PIXE (Particle Induced X-Ray Emission). Esta última foi realizada no Laboratório de Pesquisas Nucleares de Gent, Bélgica. ° modelo receptor utilizado foi a Análise de Componentes Principais (ACP) que identificou 5 perfis de fontes (5 componentes principais) para a MPF e quatro para a MPG. Para a MPF, entretanto, somente 3 fontes poluidoras puderam ser claramente identificadas: poeira do solo (ressuspensão), processos industriais e queima de óleo combustível (caldeiras). Para a MPG foram identificadas quatro fontes: poeira do solo, processos industriais, queima de óleo combustível e emissões de spray marinho. As fontes identificadas como queima de óleo combustível juntamente com as emissões industriais foram responsáveis por aproximadamente 53% da massa de MPF. Enquanto que a poeira do solo ficou responsável por 60% da massa de MPG. Verificamos com o MARS (Modelo para um Sistema Aerossol Reativo), que para concentrações molares de NH3 maiores que de S04\' o aerossol de sulfato, nitrato e amônio consiste, principalmente, de uma mistura de (NH4)2S04 e NH4N03, que podem estar dissociados ou não, dependendo da umidade relativa. Calculamos, também, as taxas de oxidação do S02 e encontramos que as taxas mais elevadas são obtidas na reação com o 02 catalisada por Mn e Fe. Com o objetivo de determinarmos a origem do S02 encontrado durante o SPACEX, estudamos a dispersão do S02 através da aplicação do modelo tipo pluma gaussiana ISC (Industrial Source Complex) da EPA (Environmental Protection Agency). Consideramos como fonte o trecho da marginal do Rio Pinheiros entre as pontes do Jaguaré e Eusébio Matoso. As estimativas obtidas com o modelo para a concentração de S02 durante o SPACEX, foram muito mais baixas que os valores medidos, indicando que existem outras fontes de grande porte contribuindo para a concentração desse poluente. A combinação desses modelos apresentou-se como uma metodologia que pode fornecer mais subsídios para a identificação das fontes e dos processos de geração da Matéria Particulada. / Receptor, Chemical Equilibrium and Dispersion Models were applied to identify the inhalable particles sources of the São Paulo Atmospheric Aerosols. The data were collected during two experiments in the São Paulo University Campus, in 1986 and 1989. The 1986 experiment was performed in the Physics Institute, and the 1989 experiment was part of the SPACEX (São Paulo Atmosphere Characterization Experiment). The fine and coarse particles (FP and CP, respectively) of the SFU samples were analyzed by PIXE and by gravimetry. The PIXE analysis were performed at the University of Gent, Selgium. Absolute Principal Component Analysis (APCA) identified five sources profiles to the FP and four to the CP. Sut, only three sources could be surely identified to the FP: resuspended soi! dust, industrial emissions and oi! burning. The sources profiles related to the CP were: resuspended soi! dust, industrial emissions, oil burning and sea-salt aerosol. The oil burning and industrial emissions were responsible for, approximately, 53% of FP, meanwhile, the soi! dust was responsible for 60% of CP. In order to predict the equilibrium concentrations of sulfate, nitrate and ammonium aerosols we applied the MARS (Model for an Aerosol Reacting System) to our data. In our case, having NH3 higher than 504 concentrations, the predicted was the following composition: (NH4)2504 and NH4N03 , that can be present dissociate or not, related to the relative humidity. The higher oxidation rates were found to the reaction of S02 with 02 catalyzed by Mn and Fe. The EPA (Environmental Protection Agency) Industrial Source Complex Model (lSC) was applied to describe the S02 dispersion from the \"Rio Pinheiros Marginal\" to the University of São Paulo Campus. The estimated values were lower than the measured ones. The combination of these models seemed to be very useful in the source profile identification of complex regions as São Paulo Metropolitan Area.

Made available in DSpace on 2016-12-23T14:04:33Z (GMT). No. of bitstreams: 1 Mayana Rigo Alves parte 1.pdf: 1590439 bytes, checksum: 71b9b8c5889a2acb01c01d6378aabf0b (MD5) Previous issue date: 2011-02-28 / A maior parte dos trabalhos científicos sobre a presença de material particulado na atmosfera está relacionada a partículas mais finas (menores que 2,5 &#956;m ou menores que 10 &#956;m), devido a seus efeitos sobre a saúde pulmonar dos seres humanos. Entretanto, partículas maiores podem causar consideráveis incômodos à população, devido a sua deposição sobre as superfícies, e a essas partículas, dá-se o nome de Material Particulado Depositado- MPD. A maior parte dos métodos experimentais para quantificação de partículas é bastante trabalhosa e onerosa, motivando o uso de métodos teóricos ou métodos indiretos de quantificação. O objetivo da aplicação da técnica indireta é reduzir o custo das medições e acelerar o tempo de obtenção dos dados. Nesse contexto, o objetivo geral deste trabalho é avaliar a hipótese da utilização de dados de Partículas Totais em Suspensão - PTS (medidos por equipamento automático) no cálculo do fluxo de deposição, substituindo o uso de medidores de deposição baseados em gravimetria. Dentro desse alvo, o presente trabalho buscou contribuir na implantação da rede de monitoramento de partículas sedimentáveis, bem como agilizar o processo de obtenção dos dados de fluxo de deposição dessas partículas. Os fluxos de deposição foram medidos no período de abril de 2009 a abril de 2010 em algumas das estações pertencentes à Rede Automática de Monitoramento da Qualidade do Ar (RAMQAR) pelo método de coleta baseado na Norma ASTM D1739 (1998). Esse mesmo fluxo foi estimado para uma das estações da rede (RAMQAR), a saber, Jardim Camburi, através de quatro modelos matemáticos. Três deles são baseados em modelos existentes na literatura e um é baseado no ajuste de curva para a obtenção da velocidade de deposição a partir dos dados experimentais de deposição. O último modelo apresentou resultados superiores aos demais. Tendo em vista o bom resultado desse último modelo, ele foi aplicado às demais estações. De forma geral, os resultados obtidos em todas as estações foram bons, conseguindo prever em 93% os valores de fluxo de deposição da região estudada. Demostrando ser uma ferramenta auxiliar para uma rápida estimativa dos fluxos de deposição onde as medições PTS estão disponíveis. No entanto, o modelo é dependente da existência de medidas de fluxo de deposição experimental para a sua calibração / Most scientific studies regarding the atmospheric aerosol is related to fine particles (less than 2.5 &#956;m or less than 10 &#956;m), due to its effects on lung health of humans; however, larger particles can cause considerable annoyance to the population, due to their deposition on surfaces (Settled Particulate Matter SPM). Most experimental methods for the quantification of these particles are laborious and expensive, motivating the use of theoretical methods or indirect methods of quantification. The aim of the indirect methods is to reduce the cost of measurements and time to obtain the data. In this context, the objective of this study is to evaluate the hypothesis using data of TSP concentration (measured by automated equipment) for calculating the deposition flux, replacing the use of experimental methods for direct measurements of deposition based on gravimetry. Within this target, this study sought to contribute in the implementation of the monitoring network of sedimentary particles as well as expedite the process of obtaining the data flow of deposition of these particles. The deposition fluxes were measured from April 2009 to April 2010 at 7 stations of the Regional Air Quality Monitoring Network (RAMQAR), by using ASTM D1739 (1998). The deposition flux was estimated by four mathematical models. Three models are based on models existing literature and one model is based on a curve fit to obtain the deposition rate from the experimental data of deposition. The latter model showed better results than others, given the successful outcome of this last model was applied to the stations. Overall, the results were satisfactory, achieving 93% predict average flux values for the region. Thus, in general, the results indicate the a simple linear fitting can be used as a aiding tool for fast estimating of deposition fluxes where TSP measurements are available. Nonetheless, the model is dependent on the existence of deposition flux measurements for calibration

Neste trabalho aplicamos três modelos: receptor, de equilíbrio químico e de dispersão, para a identificação de fontes da Matéria Particulada Inalável do aerossol atmosférico de São Paulo. Utilizamos dados de dois experimentos realizados no campus da USP em São Paulo. ° experimento realizado em 1986 teve como local de amostragem o Instituto de Física, enquanto o experimento de 1989 foi realizado no Instituto de Química como parte do SPACEX (São Paulo Atmosphere Characterization Experiment). As amostras de Matéria Particulada Fina (MPF) e Matéria Particulada Grossa (MPG) foram submetidas à análise gravimétrica e à análise PIXE (Particle Induced X-Ray Emission). Esta última foi realizada no Laboratório de Pesquisas Nucleares de Gent, Bélgica. ° modelo receptor utilizado foi a Análise de Componentes Principais (ACP) que identificou 5 perfis de fontes (5 componentes principais) para a MPF e quatro para a MPG. Para a MPF, entretanto, somente 3 fontes poluidoras puderam ser claramente identificadas: poeira do solo (ressuspensão), processos industriais e queima de óleo combustível (caldeiras). Para a MPG foram identificadas quatro fontes: poeira do solo, processos industriais, queima de óleo combustível e emissões de spray marinho. As fontes identificadas como queima de óleo combustível juntamente com as emissões industriais foram responsáveis por aproximadamente 53% da massa de MPF. Enquanto que a poeira do solo ficou responsável por 60% da massa de MPG. Verificamos com o MARS (Modelo para um Sistema Aerossol Reativo), que para concentrações molares de NH3 maiores que de S04\' o aerossol de sulfato, nitrato e amônio consiste, principalmente, de uma mistura de (NH4)2S04 e NH4N03, que podem estar dissociados ou não, dependendo da umidade relativa. Calculamos, também, as taxas de oxidação do S02 e encontramos que as taxas mais elevadas são obtidas na reação com o 02 catalisada por Mn e Fe. Com o objetivo de determinarmos a origem do S02 encontrado durante o SPACEX, estudamos a dispersão do S02 através da aplicação do modelo tipo pluma gaussiana ISC (Industrial Source Complex) da EPA (Environmental Protection Agency). Consideramos como fonte o trecho da marginal do Rio Pinheiros entre as pontes do Jaguaré e Eusébio Matoso. As estimativas obtidas com o modelo para a concentração de S02 durante o SPACEX, foram muito mais baixas que os valores medidos, indicando que existem outras fontes de grande porte contribuindo para a concentração desse poluente. A combinação desses modelos apresentou-se como uma metodologia que pode fornecer mais subsídios para a identificação das fontes e dos processos de geração da Matéria Particulada. / Receptor, Chemical Equilibrium and Dispersion Models were applied to identify the inhalable particles sources of the São Paulo Atmospheric Aerosols. The data were collected during two experiments in the São Paulo University Campus, in 1986 and 1989. The 1986 experiment was performed in the Physics Institute, and the 1989 experiment was part of the SPACEX (São Paulo Atmosphere Characterization Experiment). The fine and coarse particles (FP and CP, respectively) of the SFU samples were analyzed by PIXE and by gravimetry. The PIXE analysis were performed at the University of Gent, Selgium. Absolute Principal Component Analysis (APCA) identified five sources profiles to the FP and four to the CP. Sut, only three sources could be surely identified to the FP: resuspended soi! dust, industrial emissions and oi! burning. The sources profiles related to the CP were: resuspended soi! dust, industrial emissions, oil burning and sea-salt aerosol. The oil burning and industrial emissions were responsible for, approximately, 53% of FP, meanwhile, the soi! dust was responsible for 60% of CP. In order to predict the equilibrium concentrations of sulfate, nitrate and ammonium aerosols we applied the MARS (Model for an Aerosol Reacting System) to our data. In our case, having NH3 higher than 504 concentrations, the predicted was the following composition: (NH4)2504 and NH4N03 , that can be present dissociate or not, related to the relative humidity. The higher oxidation rates were found to the reaction of S02 with 02 catalyzed by Mn and Fe. The EPA (Environmental Protection Agency) Industrial Source Complex Model (lSC) was applied to describe the S02 dispersion from the \"Rio Pinheiros Marginal\" to the University of São Paulo Campus. The estimated values were lower than the measured ones. The combination of these models seemed to be very useful in the source profile identification of complex regions as São Paulo Metropolitan Area.

Extremely fine liquid droplets or solid particles, those remain suspended in the air, are known as aerosols. They are produced by natural sources and anthropogenic activities. Several types of aerosols produced by different processes are present in the atmosphere and every type of aerosol species exhibit different types of physical and chemical properties. Though making up only a small fraction of atmospheric mass aerosols are capable of altering Earth’s climate by scattering and absorbing incoming solar radiation and absorbing outgoing radiation. Adding to the complexity, they can act as cloud condensation nuclei and modify cloud properties. Major objective of this thesis is to study absorption due to aerosols and factors controlling the absorbing efficiency of aerosols over various environments. We have demonstrated a new method to quantify the organic carbon in terms of optical depth. Our studies demonstrate large “anomalous” absorption in the UV wavelength region over several regions. Further investigations revealed that a major part of this additional absorption is contributed by organic carbon aerosols and partly due to dust aerosols. We show that it is possible to discriminate UV absorption by dust and organic carbon by making use of the fact that dust aerosols are much larger in size compared to organic aerosols. Examination of aerosol optical depth values measured at cities south of Saharan desert indicates high short wave absorption due to coarse mode aerosols probably dust. Even at low values of Angstrom wavelength exponent, which indicates the presence of large aerosols (e.g., dust over land), absorption was found reasonably high compared to that of pure dust. On the other hand, over regions in the northern part of the Sahara close to Europe, short wave absorption was found to be lower. The enhanced short wave absorption due to coarse particles is unexpected. It appears that the deposition of anthropogenic aerosols such as black carbon over dust aerosols is likely to be responsible for this enhanced short wave absorption. This is a typical example of how anthropogenic aerosols can modify the properties of natural aerosols. We have carried out source apportionment using backward air parcel trajectories by applying k-means method of clustering and obtained various aerosol terms corresponding to each cluster. We have selected three island sites and one site in the middle of Saharan desert for this study. High aerosol radiative forcing values are observed even over remote island locations. Our study demonstrates the role of aerosols transported from the main land in influencing the aerosol environment even over remote marine regions.