The objective of this study was to investigate the spatial and temporal distribution of black carbon (BC) and possible sources by analyzing BC contents in core and sediment trap samples collected from Kao-ping submarine Canyon and surficial sediments collected from Love River, Chianjen River, Kaohsiung Harbor, Kao-ping River and adjacent coastal area. In addition, sediment core and trap samples of Kao-ping submarine Canyon, and suspended solids of Kao-ping estuary were analyzed to estimate the BC loading from Kao-ping River and the flux in Kao-ping submarine Canyon. The concentrations of BC ranged from 0.38 to 3.29 mg g-1 in this study. The results we found in coastal sediments were comparable to those in Asia, but lower than those in America and Europe. Black carbon found in surficial sediments of D2, L1 and of stations from Love River, Chianjen River and Kaohsiung Harbor were contributed from vehicle emission or coal combustion. Correlation coefficients of BC versus total polycyclic aromatic hydrocarbon (PAH) concentrations, combustion PAHs, total organic carbon (TOC) and grain size were significant in the sediments of Kao-ping River adjacent coast. Regrading to the temporal distribution of BC in Kao-ping submarine Canyon, BC and PAHs increased in the deposited sediment after 1970, that was probably related to prosperous industrial activities for last decades in Taiwan. Surficial sediments could be grouped into three clusters by hierarchical cluster analysis (HCA). Results of principal component analysis (PCA) showed principal component 1 (PC 1) could explain 35 % of total variances. Significant PC 1 compound loadings were found mostly from high molecular weight PAHs which derived mainly from combustion processes. This result was supported by the significant correlation (p<0.05) of PC 1 scores versus BC concentrations which were also mainly derived from combustion. BC fluxes for sediment cores, S1 and S37, and sediment trap of Kao-ping submarine Canyon, 0.59 g m-2 yr-1, 2.03 g m-2 yr-1 and 23 g m-2 yr-1, respectively, were comparable to those reported for surficial sediments in literature. However, BC fluxes in this study were lower than those in the sediments from Mouth of Providence River, Palos Verdes Shelf and New England Harbors, but higher than those in pelagic sediments of the Pacific Ocean. In addition, we also measured BC concentrations in suspended solid samples to estimate loadings of Kao-ping estuary which ranged from 33 to 1765 kg day-1 with an average of 602 kg day-1. Annual BC loading of Kao-ping River was roughly estimated as 29.55¡Ñ104 tons which was lower than that of the Mississippi River.

Poluentes atmosféricos como nanopartículas (N), black carbon (BC) e compostos orgânicos voláteis (COVs) são de importante compreensão para a saúde infantil devido às suas propriedades cancerígenas (N, COVs e BC), bem como podem ser causados ou intensificados sintomas irritativos (COVs e BC), cefaleia, asma, doenças pulmonares e cardíacas (BC). As partículas muito pequenas (N) ainda podem atingir os sistemas cardiovascular e cerebrovascular, e até mesmo prejudicar o desempenho escolar e cognitivo das crianças. Neste contexto, o objetivo deste trabalho foi estudar a qualidade do ar indoor (sala de aula) e outdoor (portão de acesso) em escolas, onde as crianças permanecem expostas aos poluentes por um longo período, e comparar os níveis entre os ambientes. Para isso, selecionamos duas escolas da Região Metropolitana de Porto Alegre – RMPA: uma em área urbana (Canoas); e outra em área rural (Nova Santa Rita); nas quais foram realizadas 11 campanhas quinzenais de amostragem dos poluentes atmosféricos estudados entre julho e dezembro de 2016. Em complemento, foram medidos NOx, NO2, NO e O3 e variáveis meteorológicas (temperatura, umidade relativa, radiação solar e velocidade do vento) coletados na RMPA. Foram aplicadas técnicas de sensoriamento remoto para a obtenção de imagens dos filtros de BC através de MEV. Os resultados apontam que no ambiente externo - outdoor da escola urbana os níveis máximos de BC e N ocorreram nas horas de rush, devido aos altos níveis das emissões veiculares. Na escola de Nova Santa Rita os níveis de BC e N foram ligeiramente mais baixos, possivelmente por ser um ambiente com pouca influência de fontes de emissão veicular. Por outro lado, os COVs apresentaram maiores concentrações no ambiente interior - indoor das duas escolas, as fontes de emissão destes se encontram dentro das salas de aula e não estão relacionadas com as fontes externas, ou seja, a geração dos COVs é independente de ter fontes de poluição urbana ou rural. Os níveis de BC em área urbana são regidos por fontes de emissões veiculares (outdoor), as quais são facilmente transferidas para o ar indoor, para onde podem carregar consigo outras partículas (contendo, por ex., Fe); além disso, sua dispersão é dificultada em dias frios e com menor velocidade do vento. Enquanto isso, as concentrações de COVs e N são determinadas por uma influência combinada de fontes de emissão, processos secundários de formação e meteorologia, refletindo em maior sensibilidade sob diferentes condições atmosféricas tanto outdoor quanto indoor nas áreas urbana e rural. Importa ressaltar que os dirigentes de escolas rurais devem estar atentos quanto aos níveis de COVs nas salas de aula; enquanto as escolas de centros urbanos devem triplicar a atenção, pois além de COVs há concentrações expressivas de N e BC decorrentes de emissões veiculares, principalmente nas horas de rush que coincidem com o início e fim das aulas, quando as crianças permanecem no outdoor diretamente expostas à poluição veicular. / Air pollutants as nanoparticles (N), black carbon (BC) and volatile organic compounds (VOCs) may have short and long-term adverse health effects, especially when it comes to children’s health. These pollutants are known to cause cancer and other health effects may include also eye, nose and throat irritation (VOCs and BC), headaches, asthma, pulmonary and cardiovascular diseases (BC). Air-pollution-sized nanoparticles (N) can also affect cerebrovascular system. It can negatively affect students’ learning and children’s cognition. The aim of this study was to verify and compare the indoor (classrooms) and outdoor (access gates) air quality in different schools, where the children remain exposed to air pollutants for long hours per day. Two schools in different areas of Porto Alegre Metropolitan Region (RMPA) were chosen: the first one in an urban area (Canoas) and the second one in a rural area (Nova Santa Rita). Eleven fortnightly samplings were conducted to evaluate N, BC and VOCs levels between July 2016 and December 2016. We also used data of gaseous pollutants (O3, NOx, NO2, and NO) and meteorological data (temperature, relative humidity, solar radiation and wind speed) collected in the same area. Remote sensing techniques and a scanning electron microscope (SEM) were used to obtain images of the black carbon filters. In the outdoor site of the urban school, the maximum levels of BC and N were registered in the rush hours due to a high level of vehicular carbon emissions. The lower levels of BC and N in Nova Santa Rita were attributed to the fact the school is located in a rural area, which assumes a less impacted environment. Nevertheless, this study indicates that these compounds are generated during the classroom activities, since the VOCs levels were higher in the two schools indoor sites. The black carbon particles in the urban area come from vehicle emissions (outdoor) and are easily transferred to the school indoor areas. These emissions can also carry other particles (e.g., Fe) and its dispersion can be hampered in cold days with low wind speed. VOCs and N concentrations are site-independent compounds influenced by several emission sources, reactions of primary pollutants and meteorology. It causes them to reflect with a high sensibility in different atmospheric conditions both in urban and rural areas (indoor and outdoor). We would like to emphasize that both rural and urban schools managers should be aware of the risks involving air pollutants in the classroom (especially VOCs). Urban schools boards should also remain vigilant on the expressive concentrations of N and BC near their access gates, arising from vehicle carbon emissions, which represents a risk for the children’s health.

Le carbone-suie, ou "black carbon" (BC), est considéré comme le deuxième plus grand contributeur d'origine anthropique au changement climatique, après le dioxyde de carbone, en raison de son importante capacité à absorber la lumière (Bond et al., 2013). Malgré son influence sur le système climatique, les observations pluriannuelles des teneurs atmosphériques de BC demeurent rares, particulièrement en Europe. Cette étude propose une reconstruction nouvelle de la variabilité passée du BC atmosphérique à partir de l'analyse d'une carotte de glace forée au glacier de l'Elbrus (ELB), situé dans le Caucase en Russie. Un analyseur de carbone-suie SP2 (Single Particle Soot Photometer) a été exploité pour l'analyse du BC réfractaire (rBC) sur 153m de carotte de glace couvrant les derniers 140 ans. Un nouveau système analytique couplant un nébuliseur APEX-Q et le SP2, intégré au sein d'un système d'Analyse en Flux Continu, a été développée et a permis d'obtenir un enregistrement unique quasi-continu du rBC. La glace de l'Elbrus révèle une augmentation marquée des teneurs en rBC entre les années 1870 et 1980, suivie d'une diminution des concentrations jusqu'en 2000 environ. Au cours de la dernière décennie, les concentrations en rBC demeurent stables. Parallèlement, une augmentation des niveaux de fond jusqu'en 1980 indique clairement un impact non négligeable des émissions anthropiques sur la charge en BC atmosphérique à des échelles spatiales très larges, et notamment dans la troposphère libre. Une étude fine des inventaires d'émissions de BC disponibles et la modélisation FLEXPART viennent confirmer que l'augmentation forte de rBC depuis 1920 est principalement due aux émissions anthropiques de BC. Une analyse du gradient est-ouest des dépôts de rBC à haute altitude au cours de la dernière décennie a été réalisée, en comparant l'archive récente (10 ans) de l'Elbrus avec deux autres enregistrements provenant du Col du Dôme (CDD, France) et du Colle Gnifetti (CG, Italie). Les concentrations à l'Elbrus se révèlent deux à trois fois supérieures à celles des autres sites, une différence liée à l'intensité plus forte des sources en Europe de l'Est et confirmée par la modélisation FLEXPART. Les combustions de biomasse se trouvent identifiées comme la principale cause de variabilité interannuelle à l'Elbrus en été. Sur les derniers 10 ans, une diminution statistiquement significative des concentrations en rBC dans la neige est détectée au CDD, un résultat qui s'oppose aux observations réalisées à l'Elbrus où une tendance à l'augmentation au cours des périodes estivales est identifiée. Ces tendances, aussi bien CDD et ELB, sont relativement cohérentes avec les inventaires d'émissions de BC anthropiques disponibles. Ces enregistrements nouveaux et continus de rBC dans plusieurs carottes de glace européennes viennent faire progresser notre compréhension des évolutions passées des sources et de la charge atmosphérique du BC en Europe. Ces enregistrements peuvent participer à une meilleure évaluation de l'efficacité des politiques passées et actuelles de réduction des émissions de BC, ainsi qu'à une amélioration des inventaires d'émission. / Black carbon (BC) is considered as the second largest man-made contributor to global warming after carbon dioxide due to its highly light-absorbing ability (Bond et al., 2013). Despite its climatic role, multi-year observations of ambient BC concentrations are scarce, in particular over Europe. In this thesis, we reconstructed past variability of atmospheric BC using an ice core from the Elbrus glacier (ELB), Caucasus in Russia. We have used a single particle soot photometer (SP2) to retrieve refractive BC (rBC) along 153 m of ice core covering the last 140 years. We have developed and validated a novel analytical system coupling of APEX-Q nebulization to SP2 in a Continuous-flow Analysis system to derive a unique quasi-continuous record of rBC. Results reveal a substantial rBC increase since 1870s lasting until 1980, followed by a decrease until ~2000. In the last decade, rBC concentrations remained constant. In parallel, an increase in background concentration until 1980 clearly highlights that anthropogenic BC emissions have substantially affected the atmospheric BC loading on a very large spatial scale, particularly in the free troposphere. A comparison with the estimated BC reaching the ELB site using a BC emission inventory/FLEXPART modeling confirms that the strong rBC increase since around 1920 is mainly due to anthropogenic BC emissions. Analysis of the East-West gradient of rBC deposited in snow over the last decade is investigated comparing the recent archive (10-year) at ELB with two other records from Col du Dôme (CDD), France, and Colle Gnifetti (CG), Italy. Concentrations at ELB are 2-3 times higher than at other sites, which is linked to source intensity in the Eastern part of Europe, as confirmed by the FLEXPART modelling. Biomass burning is identified as a main cause of inter-annual variability at ELB during summer time. Over the last decade, a statistically significant reduction of rBC concentration in snow is found at CDD, opposite to what is found at ELB with an increasing trend observed for summer periods. These trends are also fairly consistent with anthropogenic BC emissions inventories. Availability of continuous records of rBC in European ice cores improved our understanding of past evolution of atmospheric BC over Europe. They can be used to assess efficiency of past and current emission reduction policies and improve emission inventories.

Poluentes atmosféricos como nanopartículas (N), black carbon (BC) e compostos orgânicos voláteis (COVs) são de importante compreensão para a saúde infantil devido às suas propriedades cancerígenas (N, COVs e BC), bem como podem ser causados ou intensificados sintomas irritativos (COVs e BC), cefaleia, asma, doenças pulmonares e cardíacas (BC). As partículas muito pequenas (N) ainda podem atingir os sistemas cardiovascular e cerebrovascular, e até mesmo prejudicar o desempenho escolar e cognitivo das crianças. Neste contexto, o objetivo deste trabalho foi estudar a qualidade do ar indoor (sala de aula) e outdoor (portão de acesso) em escolas, onde as crianças permanecem expostas aos poluentes por um longo período, e comparar os níveis entre os ambientes. Para isso, selecionamos duas escolas da Região Metropolitana de Porto Alegre – RMPA: uma em área urbana (Canoas); e outra em área rural (Nova Santa Rita); nas quais foram realizadas 11 campanhas quinzenais de amostragem dos poluentes atmosféricos estudados entre julho e dezembro de 2016. Em complemento, foram medidos NOx, NO2, NO e O3 e variáveis meteorológicas (temperatura, umidade relativa, radiação solar e velocidade do vento) coletados na RMPA. Foram aplicadas técnicas de sensoriamento remoto para a obtenção de imagens dos filtros de BC através de MEV. Os resultados apontam que no ambiente externo - outdoor da escola urbana os níveis máximos de BC e N ocorreram nas horas de rush, devido aos altos níveis das emissões veiculares. Na escola de Nova Santa Rita os níveis de BC e N foram ligeiramente mais baixos, possivelmente por ser um ambiente com pouca influência de fontes de emissão veicular. Por outro lado, os COVs apresentaram maiores concentrações no ambiente interior - indoor das duas escolas, as fontes de emissão destes se encontram dentro das salas de aula e não estão relacionadas com as fontes externas, ou seja, a geração dos COVs é independente de ter fontes de poluição urbana ou rural. Os níveis de BC em área urbana são regidos por fontes de emissões veiculares (outdoor), as quais são facilmente transferidas para o ar indoor, para onde podem carregar consigo outras partículas (contendo, por ex., Fe); além disso, sua dispersão é dificultada em dias frios e com menor velocidade do vento. Enquanto isso, as concentrações de COVs e N são determinadas por uma influência combinada de fontes de emissão, processos secundários de formação e meteorologia, refletindo em maior sensibilidade sob diferentes condições atmosféricas tanto outdoor quanto indoor nas áreas urbana e rural. Importa ressaltar que os dirigentes de escolas rurais devem estar atentos quanto aos níveis de COVs nas salas de aula; enquanto as escolas de centros urbanos devem triplicar a atenção, pois além de COVs há concentrações expressivas de N e BC decorrentes de emissões veiculares, principalmente nas horas de rush que coincidem com o início e fim das aulas, quando as crianças permanecem no outdoor diretamente expostas à poluição veicular. / Air pollutants as nanoparticles (N), black carbon (BC) and volatile organic compounds (VOCs) may have short and long-term adverse health effects, especially when it comes to children’s health. These pollutants are known to cause cancer and other health effects may include also eye, nose and throat irritation (VOCs and BC), headaches, asthma, pulmonary and cardiovascular diseases (BC). Air-pollution-sized nanoparticles (N) can also affect cerebrovascular system. It can negatively affect students’ learning and children’s cognition. The aim of this study was to verify and compare the indoor (classrooms) and outdoor (access gates) air quality in different schools, where the children remain exposed to air pollutants for long hours per day. Two schools in different areas of Porto Alegre Metropolitan Region (RMPA) were chosen: the first one in an urban area (Canoas) and the second one in a rural area (Nova Santa Rita). Eleven fortnightly samplings were conducted to evaluate N, BC and VOCs levels between July 2016 and December 2016. We also used data of gaseous pollutants (O3, NOx, NO2, and NO) and meteorological data (temperature, relative humidity, solar radiation and wind speed) collected in the same area. Remote sensing techniques and a scanning electron microscope (SEM) were used to obtain images of the black carbon filters. In the outdoor site of the urban school, the maximum levels of BC and N were registered in the rush hours due to a high level of vehicular carbon emissions. The lower levels of BC and N in Nova Santa Rita were attributed to the fact the school is located in a rural area, which assumes a less impacted environment. Nevertheless, this study indicates that these compounds are generated during the classroom activities, since the VOCs levels were higher in the two schools indoor sites. The black carbon particles in the urban area come from vehicle emissions (outdoor) and are easily transferred to the school indoor areas. These emissions can also carry other particles (e.g., Fe) and its dispersion can be hampered in cold days with low wind speed. VOCs and N concentrations are site-independent compounds influenced by several emission sources, reactions of primary pollutants and meteorology. It causes them to reflect with a high sensibility in different atmospheric conditions both in urban and rural areas (indoor and outdoor). We would like to emphasize that both rural and urban schools managers should be aware of the risks involving air pollutants in the classroom (especially VOCs). Urban schools boards should also remain vigilant on the expressive concentrations of N and BC near their access gates, arising from vehicle carbon emissions, which represents a risk for the children’s health.

Biochar has been heralded a mechanism for carbon sequestration and an ideal amendment for improving soil quality. Melaleuca quinquenervia is an aggressive and wide-spread invasive species in Florida. The purpose of this research was to convert M. quinquenervia biomass into biochar and measure how application at two rates (2% or 5% wt/wt) impacts soil quality, plant growth, and microbial gas flux in a greenhouse experiment using Phaseolus vulgaris L. and local soil. Plant growth was measured using height, biomass weight, specific leaf area, and root-shoot ratio. Soil quality was evaluated according to nutrient content and water holding capacity. Microbial respiration, as carbon dioxide (CO2), was measured using gas chromatography. Biochar addition at 5% significantly reduced available soil nutrients, while 2% biochar application increased almost all nutrients. Plant biomass was highest in the control group, p2 flux decreased significantly in both biochar groups, but reductions were not long term.

Black carbon (BC), the incomplete combustion product from biomass and fossil fuel burning, is ubiquitously found in soils, sediments, ice, water and atmosphere. Because of its polyaromatic molecular characteristic, BC is believed to contribute significantly to the global carbon budget as a slow-cycling, refractory carbon pool. However, the mass balance between global BC generation and accumulation does not match, suggesting a removal mechanism of BC to the active carbon pool, most probable in a dissolved form. The presence of BC in waters as part of the dissolved organic matter (DOM) pool was recently confirmed via ultrahigh resolution mass spectrometry, and dissolved black carbon (DBC), a degradation product of charcoal, was found in marine and coastal environments. However, information on the loadings of DBC in freshwater environments and its global riverine flux from terrestrial systems to the oceans remained unclear. The main objectives of this study were to quantify DBC in diverse aquatic ecosystems and to determine its environmental dynamics. Surface water samples were collected from aquatic environments with a spatially significant global distribution, and DBC concentrations were determined by a chemical oxidation method coupled with HPLC detection. While it was clear that biomass burning was the main sources of BC, the translocation mechanism of BC to the dissolved phase was not well understood. Data from the regional studies and the developed global model revealed a strong positive correlation between DBC and dissolved organic carbon (DOC) dynamics, indicating a co-generation and co-translocation between soil OC and BC. In addition, a DOC-assistant DBC translocation mechanism was identified. Taking advantage of the DOC-DBC correlation model, a global riverine DBC flux to oceans on the order of 26.5 Mt C yr-1 (1 Mt = 1012 g) was determined, accounting for 10.6% of the global DOC flux. The results not only indicated that DOC was an important environmental intermediate for BC transfer and storage, but also provided an estimate of a major missing link in the global BC budget. The ever increasing DBC export caused by global warming will change the marine DOM quality and may have important consequences for carbon cycling in marine ecosystem.

Poluentes atmosféricos como nanopartículas (N), black carbon (BC) e compostos orgânicos voláteis (COVs) são de importante compreensão para a saúde infantil devido às suas propriedades cancerígenas (N, COVs e BC), bem como podem ser causados ou intensificados sintomas irritativos (COVs e BC), cefaleia, asma, doenças pulmonares e cardíacas (BC). As partículas muito pequenas (N) ainda podem atingir os sistemas cardiovascular e cerebrovascular, e até mesmo prejudicar o desempenho escolar e cognitivo das crianças. Neste contexto, o objetivo deste trabalho foi estudar a qualidade do ar indoor (sala de aula) e outdoor (portão de acesso) em escolas, onde as crianças permanecem expostas aos poluentes por um longo período, e comparar os níveis entre os ambientes. Para isso, selecionamos duas escolas da Região Metropolitana de Porto Alegre – RMPA: uma em área urbana (Canoas); e outra em área rural (Nova Santa Rita); nas quais foram realizadas 11 campanhas quinzenais de amostragem dos poluentes atmosféricos estudados entre julho e dezembro de 2016. Em complemento, foram medidos NOx, NO2, NO e O3 e variáveis meteorológicas (temperatura, umidade relativa, radiação solar e velocidade do vento) coletados na RMPA. Foram aplicadas técnicas de sensoriamento remoto para a obtenção de imagens dos filtros de BC através de MEV. Os resultados apontam que no ambiente externo - outdoor da escola urbana os níveis máximos de BC e N ocorreram nas horas de rush, devido aos altos níveis das emissões veiculares. Na escola de Nova Santa Rita os níveis de BC e N foram ligeiramente mais baixos, possivelmente por ser um ambiente com pouca influência de fontes de emissão veicular. Por outro lado, os COVs apresentaram maiores concentrações no ambiente interior - indoor das duas escolas, as fontes de emissão destes se encontram dentro das salas de aula e não estão relacionadas com as fontes externas, ou seja, a geração dos COVs é independente de ter fontes de poluição urbana ou rural. Os níveis de BC em área urbana são regidos por fontes de emissões veiculares (outdoor), as quais são facilmente transferidas para o ar indoor, para onde podem carregar consigo outras partículas (contendo, por ex., Fe); além disso, sua dispersão é dificultada em dias frios e com menor velocidade do vento. Enquanto isso, as concentrações de COVs e N são determinadas por uma influência combinada de fontes de emissão, processos secundários de formação e meteorologia, refletindo em maior sensibilidade sob diferentes condições atmosféricas tanto outdoor quanto indoor nas áreas urbana e rural. Importa ressaltar que os dirigentes de escolas rurais devem estar atentos quanto aos níveis de COVs nas salas de aula; enquanto as escolas de centros urbanos devem triplicar a atenção, pois além de COVs há concentrações expressivas de N e BC decorrentes de emissões veiculares, principalmente nas horas de rush que coincidem com o início e fim das aulas, quando as crianças permanecem no outdoor diretamente expostas à poluição veicular. / Air pollutants as nanoparticles (N), black carbon (BC) and volatile organic compounds (VOCs) may have short and long-term adverse health effects, especially when it comes to children’s health. These pollutants are known to cause cancer and other health effects may include also eye, nose and throat irritation (VOCs and BC), headaches, asthma, pulmonary and cardiovascular diseases (BC). Air-pollution-sized nanoparticles (N) can also affect cerebrovascular system. It can negatively affect students’ learning and children’s cognition. The aim of this study was to verify and compare the indoor (classrooms) and outdoor (access gates) air quality in different schools, where the children remain exposed to air pollutants for long hours per day. Two schools in different areas of Porto Alegre Metropolitan Region (RMPA) were chosen: the first one in an urban area (Canoas) and the second one in a rural area (Nova Santa Rita). Eleven fortnightly samplings were conducted to evaluate N, BC and VOCs levels between July 2016 and December 2016. We also used data of gaseous pollutants (O3, NOx, NO2, and NO) and meteorological data (temperature, relative humidity, solar radiation and wind speed) collected in the same area. Remote sensing techniques and a scanning electron microscope (SEM) were used to obtain images of the black carbon filters. In the outdoor site of the urban school, the maximum levels of BC and N were registered in the rush hours due to a high level of vehicular carbon emissions. The lower levels of BC and N in Nova Santa Rita were attributed to the fact the school is located in a rural area, which assumes a less impacted environment. Nevertheless, this study indicates that these compounds are generated during the classroom activities, since the VOCs levels were higher in the two schools indoor sites. The black carbon particles in the urban area come from vehicle emissions (outdoor) and are easily transferred to the school indoor areas. These emissions can also carry other particles (e.g., Fe) and its dispersion can be hampered in cold days with low wind speed. VOCs and N concentrations are site-independent compounds influenced by several emission sources, reactions of primary pollutants and meteorology. It causes them to reflect with a high sensibility in different atmospheric conditions both in urban and rural areas (indoor and outdoor). We would like to emphasize that both rural and urban schools managers should be aware of the risks involving air pollutants in the classroom (especially VOCs). Urban schools boards should also remain vigilant on the expressive concentrations of N and BC near their access gates, arising from vehicle carbon emissions, which represents a risk for the children’s health.

Chaque année, une quantité de 107tonnes de suie est produite à l'échelle mondiale. Le carbone-suie dans l'atmosphère a des effets graves sur le changement climatique et la santé humaine. Les impacts dépendent de nombreux facteurs comme les composés organiques adsorbés, le vieillissement et les processus de mélange. Par conséquent, afin de réduire la quantité de suie émise, outre l'examen des facteurs mentionnés, les études de la cinétique de formation, de la structure et des propriétés optiques des suies sont également essentielles. Il existe plusieurs méthodes optiques dans les études sur la suie. La spectroscopie Raman occupe un rôle particulier puisqu'elle est un outil puissant pour l'étude structurale des matériaux carbonés grâce à sa sensibilité aux structures à l’échelle moléculaire. Dans ce travail, des sections Raman différentielles de suies et quelques autres particules carbonées ont été mesurées pour progresser vers la spectroscopie Raman quantitative de ces particules. Les suies produites par des flammes d'éthylène pré-mélangées à basse pression ont été étudiées par mesure Raman ex-situ sur des films déposés et des mesures Raman in-situ (enligne) dans la phase gazeuse. La combinaison de la spectroscopie Raman de suies échantillonnées sur substrat avec les spectroscopies infrarouge et optique et la microscopie électronique en transmission a permis de progresser sur l'interprétation des spectres Raman de suie. Les mesures en phase gazeuse, obtenues pour la première fois, fournissent de nouvelles informations sur la naissance des suies et leurs structures dans les flammes à basse pression avec, par exemple, la détection d'une grande quantité d'atomes de carbones hybridés sp lors de la formation et de la croissance des premières suies. Ces étude s’ouvrent la voie à la détection et à l'analyse des suies directement en phase gazeuse et à leur détection quantitative dans l’atmosphère au travers de leurs spectres Raman. / Every year, an amount of 107 tons of soot is produced on the world scale. Soot, as part of atmospheric black carbon, has serious impacts on climate change and human health. The impacts depend on many factors including adsorbed compounds, aging and mixing processes. Therefore in order to reduce the soot amount, besides considering these mentioned factors, the study of formation kinetics, structure and optical properties is also essential. There are several methods applied in soot investigations. Raman spectroscopy plays a particular role as it is a powerful tool for structural investigation of the carbon-based materials because it is sensitive to molecular structures. In this work, differential Raman cross sections of soot and some other carbonaceous particles were measured to progress toward quantitative Raman spectroscopy. Soot particles produced by premixed ethylene flames at a low pressure were investigated by ex-situ Raman measurement on deposited films and in-situ(online) Raman measurement in the gas phase. Combination of the Raman spectroscopy of soot sampled on substrates with infrared and optical spectroscopy and transmission electron microscopy allowed progressing on the interpretation of soot Raman spectra. The online gas phase measurements provided a novel view on soot birth and structures in low pressure flames with, for instance, the detection of a large amount of sp hybrized carbon atoms during nascent soot growth. These studies pave the way to soot detection and analysis directly and quantitatively in the atmosphere.

No description available.

No description available.