High Arctic permafrosted soils represent a massive sink in the global carbon cycle, accounting for twice as much carbon as what is currently stored as carbon dioxide in the atmosphere. However, with current warming trends this sink is in danger of thawing and potentially releasing large amounts of carbon as both carbon dioxide and methane into the atmosphere. It is difficult to make predictions about the future of this sink without knowing how it has reacted to past temperature and climate changes. This dissertation summarizes the results of the first study to look at long term, fine scale organic carbon delivery by the high-Arctic Colville River into Simpson’s Lagoon in the near-shore Beaufort Sea. Modern delivery of organic carbon to the Lagoon was determined to come from a variety of sources through the use of a three end-member mixing model and sediment biomarker concentrations. These sources include the Colville River in the western area of the Lagoon near the river mouth, marine sources in areas of the Lagoon without protective barrier islands, and coastal erosional sources and the Mackenzie River in the eastern area of the Lagoon. Downcore organic carbon delivery was measured on two cores in the Lagoon, one taken near the mouth of the Colville River (spans about 1800 years of history) and one taken on the eastern end of the Lagoon (spans about 600 years of history). Bulk organic parameters and biomarkers were measured in both cores and analyzed with Principle Component Analysis to determine long-term trends in organic carbon delivery. It was shown that at various times in the past, highly degraded organic carbon inputs of what is likely soil and peat carbon were delivered to the Lagoon. At other times, inputs of fresher, non-degraded, terrestrially-derived organic carbon inputs of what are likely higher amounts of plant and vegetative material was delivered to the Lagoon. Inputs of degraded soil carbon were also shown to correspond to higher temperatures on the North Slope of Alaska, likely indicating that warmer temperatures lead to a thawing of permafrost and in turn organic carbon mobilization to the coastal Beaufort Sea.

The objective of this study was onboard testing of a mixed metal oxide diesel soot oxidation catalyst composing of oxides of lead and cobalt previously developed in our lab, by mounting a diesel particulate filter (DPF), which is coated with this catalyst, to the exhaust stream of a diesel vehicle. Commercial wall flow type DPF&rsquo / s (Corning EX-80) were coated with the catalyst by a slurry wash-coating procedure and then mounted on the exhaust stream of a diesel light duty vehicle (LDV) provided by TOFAS (FIAT Doblo 1.9 JTD). These vehicles were driven on the rollers of the chassis dynamometer at constant speed and gear for two different loading conditions and on a standard driving cycle (NEDC) in the Test and Emission Laboratory of TOFAS-FIAT. The exhaust gases were analyzed for NOx, CO, CO2, THC and PM. The pressure drop caused by the filter was monitored during these tests as an indication of soot accumulation on the filter with the help of pressure sensors placed before and after the filter. Also temperatures before, inside and after the filter were monitored by means of thermocouples. Three different filters were tested in this manner: (1) Monocoated (CoOx), (2) Sequential PbOx coated over CoOx (PbOx/CoOx), (3) Simultaneously coated (PbCoOx). Also tests with the uncoated filter were performed to determine the pressure drops as a result of non-catalytic soot oxidation. The performances of the catalytic filters were evaluated by determining the temperature at which the soot oxidation rate on the filter equals the soot production rate in the engine (balance point temperature-Tbal). This temperature was used for comparing the catalytic activity of the supported catalyst with that of the powder form tested in the laboratory, i. e. Tpeak. The results of the onboard test were in parallel with the previous laboratory studies with similar catalytic activity temperatures. The continuous regeneration temperatures (Tbal) obtained in onboard tests with PbOx/CoOx and PbCoOx filters of about 370oC, which was close to the values attained in the lab study with the same mixed metal oxide catalyst having a Tpeak value of 385oC. Also the PM emissions during the tests were complying with the current EURO-IV emission limits.

Σκοπός της παρούσας διπλωματικής εργασίας είναι η μελέτη της επίδρασης της θερμικής κόπωσης στη μηχανική συμπεριφορά κοκκωδών συνθέτων υλικών πολυμερικής μήτρας ενισχυμένης με κόκκους ελαιοπυρήνα υπό μορφή σκόνης. Τα σύνθετα υλικά που κατασκευάσθηκαν μελετήθηκαν πειραματικά και τα αποτελέσματα αναλύθηκαν και προβλέφθηκαν θεωρητικά. Αρχικά πραγματοποίηθηκε η κατασκευή των συνθέτων υλικών σε διάφορες περιεκτικότητες σε κόκκους ελαιοπυρήνα. Από τον μηχανικό χαρακτηρισμό με στατικά πειράματα κάμψης τριών σημείων όλων των συνθέτων υλικών που κατασκευάστηκαν, διαπιστώθηκε η ενισχυτική ικανότητα του ελαιοπυρήνα σε μορφή σκόνης όταν αυτή χρησιμοποιείται ως υλικό ενίσχυσης για την κατασκευή συνθέτων υλικών. Ενώ, στη συνέχεια μελετήθηκε και η επίδραση της θερμικής κόπωσης στη μηχανική συμπεριφορά των συνθέτων υλικών που κατασκευάστηκαν. Τέλος, εφαρμόστηκαν δύο διαφορετικά μοντέλα πρόβλεψης του μέτρου ελαστικότητας συναρτήσει της περιεκτικότητας καθώς και της εναπομείνουσας αντοχής και δυσκαμψίας συναρτήσει των κύκλων θερμικής κόπωσης και έγινε σύγκριση των πειραματικών αποτελεσμάτων με τις αντίστοιχες προβλέψεις. Από τη σύγκριση αυτή παρατηρούμε ότι τα θεωρητικά μοντέλα που εφαρμόστηκαν που είναι το Μ.P.M (Modulus Predictive Model) και το R.P.M (Residual Properties Model) έδωσαν πολύ καλές προβλέψεις για την μεταβολή των ιδιοτήτων. Σαν γενικό συμπέρασμα από την παρούσα εργασία προκύπτει το γεγονός ότι το φθηνό και ελαφρύ υλικό του ελαιοπυρήνα μπορεί να χρησιμοποιηθεί αποτελεσματικά σαν υλικό ενίσχυσης ρητινών με πολύ καλά αποτελέσματα ενίσχυσης. / The aim of the present master thesis is to investigate the effect of thermal fatigue on the mechanical properties of particulate composites reinforced with olive pit’s powder. The composites materials that have been manufactured were investigated both; experimentally and theoretically. First, we manufactured composites reinforced with olive pits at different volume fractions of the filler particles. From the mechanical characterization of the materials investigated by means of static three-point bending experiments. It was found that the olive pits can reinforce the mechanical properties of composites materials when used as reinforced fillers. Next, the effect of thermal fatigue on the mechanical behaviour of the composites materials was investigated and theoretical predictions for their properties with and without thermal fatigue were made. More precisely, the Μ.P.M (Modulus Predictive Model) and the R.P.M (Residual Properties Model) models have been applied. A fair aggreement between experimental findings and theoretical predictions was found in all cases.

La mesure de Matières En Suspension (MES) est cruciale autant pour comprendre les transferts sédimentaires que pour les études des écosystèmes marins. Elles sont classiquement mesurées ponctuellement par des prélèvements d’eau in situ, ou à partir des propriétés optiques de l’eau. Mais depuis plusieurs décennies, les appareils acoustiques, ont montré leur capacité à mesurer ces MES sur de plus grands volumes. Ces mesures, en particulier celles de la concentration, s’appuient sur les propriétés de rétrodiffusion des particules. Mais ces mesures demeurent peu représentatives dans la mesure où le contenu en MES dans la colonne d’eau varie à différentes échelles de temps et d’espace. Dans un premier temps, ces travaux de thèse visent à montrer à travers des mesures in situ réalisées dans l’estuaire de l’Aulne qu’il est possible d’étendre spatialement la mesure par inversion des données issues de sondeurs multifaisceaux (SMF). Un modèle de rétrodiffusion adapté à la suspension d’intérêt, constituée dans cette étude d’agrégats estuariens, est d’abord élaboré. Puis grâce à des observations issues d’un profileur multifréquences, la concentration massique en MES, distribuée par classes de tailles, a pu être déterminée par la résolution d’un problème inverse. Ces informations permettent de déterminer les rayons équivalents de la suspension, grâce auxquels les données issues du SMF, au préalable calibrées par une méthode innovante, peuvent être inversées de manière directe. Une étude des incertitudes attachées aux valeurs de concentrations estimées est par la suite proposée afin de qualifier la pertinence des résultats. Puis dans un second temps, les conditions nécessaires à l’établissement d’un protocole de mesure des MES par système multi-capteur sont identifiées. Ce dernier permet la caractérisation en continu des MES à différentes échelles de temps et d’espace, en exploitant la complémentarité des mesures issues des différents instruments. / Measuring Suspended Particulate Matter (SPM) is essential to better understand sediment transport and marine ecosystems. SPM is traditionnaly estimated through in situ water samples analysis, or based on the optical properties of water. Yet for several decades, acoustical devices have shown their capability to measure SPM on larger volumes. These measurements (especially in terms of SPM concentration) are based on the backscattering properties of the particles. However, these measurements remain limited, since the SPM content in the water column is subjected to variations on both spatial and temporal scales.As a first step, this work aims at showing that it is possible to increase the degree of spatialization of the SPM measurements by inverting MultiBeam EchoSounder (MBES) data, through in situ measurements acquired in the Aulne macrotidal estuary. A backscattering model was first designed to describe the backscattering properties of the suspension of interest, consisting in this study in estuarine agregates. Then, thanks to multifrequency observations, the SPM mass concentration sorted by size classes was retrieved through the the resolution of the inverse problem. This kind of information allows to determine the equivalent spherical radius of the the whole suspension, through which the MBES data, calibrated beforehand using an original method, can be directly inverted. Subsequently, a study of the uncertainties attached to the final concentration estimate is proposed in order to qualify the relevance of the results.In a second step, the necessary conditions for establishing a measurement protocol of the SPM are identified. The latter allows continuous characterization of SPM at different spatial and temporal scales, by exploiting the complementarity of the measures delivered by different instruments.

Submitted by Isaías Mutombo Mafavisse (isaimutombo@yahoo.com.br) on 2018-07-20T10:15:20Z No. of bitstreams: 1 TESE_2018 ISAIAS MAFAVISSE.pdf: 5746929 bytes, checksum: f2429d8c5245df253586397aeecc0a09 (MD5) / Approved for entry into archive by Lucimara Kurokawa Shinoda null (lucimaraks@sorocaba.unesp.br) on 2018-07-20T17:16:21Z (GMT) No. of bitstreams: 1 mafavisse_im_dr_soro.pdf: 5746929 bytes, checksum: f2429d8c5245df253586397aeecc0a09 (MD5) / Made available in DSpace on 2018-07-20T17:16:21Z (GMT). No. of bitstreams: 1 mafavisse_im_dr_soro.pdf: 5746929 bytes, checksum: f2429d8c5245df253586397aeecc0a09 (MD5) Previous issue date: 2018-06-21 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A poluição do ar é considerada uma situação-tipo para o setor mineiro, apresentando aspectos clássicos de degradação do meio ambiente biótico e abiótico. O objetivo do trabalho é identificar áreas impactadas por material particulado da mineração do carvão e suas principais fontes emissoras em Moatize, propondo uma nova formulação de supressor de poeira de base vegetal como alternativa para reduzir a emissão de material particulado em mina a céu aberto. Através de metodologia cartográfica, buscou-se representar as áreas críticas contendo carga potencial poluidora, neste caso, partículas totais em suspensão (PTS) e material particulado respirável (MP10) procedentes do processo e logística da exploração do carvão. As variações na qualidade do ar em torno das áreas de mineração do carvão em Moatize foram avaliadas durante o período de 2015 em cinco locais e em duas estações do ano. Os dados de campo mostraram que as áreas mais impactadas pelas emissões difusas de partículas totais em suspensão (PTS) e material particulado com diâmetro 10 (MP10) devido à atividade de mineração do carvão em Moatize são Liberdade, Carbomoc, Minas Moatize e 25 de setembro. Este último é o mais impactado. Os dados revelaram ainda níveis de concentração de material particulado acima dos padrões estabelecidos no Regulamento de Normas de Qualidade Ambiental e Decreto de Emissão de Efluentes n° 67/2010 vigente em Moçambique. As concentrações de PTS atingiram 569 μg m-3 no mês mais crítico. As análises de elementos principais e de elementos maiores e traço no carvão bruto foram realizadas por Análise Elementar CHN e Espetroscopia de Emissão óptica com Plasma Acoplado Indutivamente (ICP OES). Na formulação básica do supressor de poeira foi examinado o supressor de extrato de Pinus e ácido γ-poliglutâmico (γ-PGA). A nova formulação contendo ácido γ-poliglutâmico resultou em supressor de poeira de base vegetal, biodegradável. A interface entre a matriz de carvão mineral e a película supressora foi examinada por microscopia confocal de varredura a laser. Na caracterização do supressor de poeira foram utilizadas técnicas de microscopia eletrônica de varredura e espectroscopia no infravermelho. O gênero Pinus é uma matéria-prima abundante, renovável e de baixo custo, que possui potencial químico para o desenvolvimento de novos produtos de alto valor agregado. Os resultados iniciais são promissores e representam não apenas uma vantagem ambiental, mas também um ganho importante para as comunidades localizadas nas imediações das minas de carvão. / Air pollution is considered a standard situation for the mining sector, presenting classic aspects of degradation of the biotic and abiotic environment. The objective of this work is to identify areas impacted by coal mining particulate matter and its main source sources in Moatize, proposing a new formulation of a dust suppressant which is plant base with an alternative to suppress the particulate matter in an open pit mine. By means of cartographic methodology, we intend to represent the critical areas with potential pollutant load, in this case, total suspended particulate (TSP) matter and respirable particulate matter (PM10) from the process and logistic of the coal exploitation. The variations in air quality around the coal mining areas at Moatize were assessed over the 2015 period at five sites and two seasons. The field data showed that the areas most impacted by the diffuse emissions of TSP matter and PM10 particulate due to the coal mining activity in Moatize are Liberdade, Carbomoc, Minas Moatize on September 25. The latter is the most impacted. The data also revealed a high concentration of particulate matter in these areas, with levels above the standards established in the Regulation of Environmental Quality Standards and Wastewater Emission Decree No. 67/2010 in force in Mozambique. The PTS concentrations reached 569 μg m-3 in the most critical month. The analyzes of major elements and major elements and trait in crude coal were performed by CHN elementary and inductively coupled plasma optical emission spectrometers (ICP OES). In the basic formulation of the dust suppressant the extract suppressor of Pinus and γ-polyglutamic acid (γ-PGA) was examined. The new formulation containing γ-polyglutamic acid resulted in a biodegradable plant-based dust suppressant. The interface between the charcoal matrix and the suppressor film was examined by a laser scanning confocal microscopy. In the characterization of the dust suppressor, scanning electron microscopy and infrared spectroscopy techniques were used. The Pinus genus is an abundant, renewable and low-cost raw material that has chemical potential for the development of new products with high added value. The initial results are promising and represent not only an environmental advantage, but also a significant gain for communities located in the vicinity of coal mines.

La maîtrise de la contamination générée par temps de pluie en milieu urbain constitue un enjeu environnemental important pour limiter la dégradation des milieux aquatiques superficiels. Les outils de modélisation traditionnelle utilisés pour estimer les flux de polluants dans les eaux de ruissellement sont jugés insuffisants dans leur capacité à reproduire les dynamiques des polluants à l’exutoire. Cela est souvent lié au manque de connaissances précises sur les processus en jeu d’une part, et d’autre part aux difficultés d’acquérir des bases de données représentatives et en continu sur des sites réels. Cette thèse a donc pour objectif d’améliorer l’état de la modélisation de la qualité. Elle vise en particulier le développement d’un outil de modélisation conceptuelle de la qualité des eaux de ruissellement à l’échelle du quartier, à partir d’une compréhension approfondie des processus d'accumulation et de lessivage. La simulation des pollutogrammes de matières en suspension (MES) à l’avaloir du bassin versant routier avec les modèles conceptuels d’accumulation-lessivage montre la faible performance des modèles pour estimer les dynamiques d’émissions de MES pour des longues périodes ; la variabilité du processus d’accumulation est le responsable principal de l’inadéquation de ces modèles. L’évaluation de la contribution des retombées atmosphériques sèches à la contamination des eaux de ruissellement en hydrocarbures aromatiques polycycliques (HAPs) et métaux montrent que l’atmosphère ne joue qu’un rôle très mineur dans la contamination des eaux de ruissellement par ces substances. Ainsi le couplage des modèles atmosphériques, qui ne tiennent pas compte des émissions directes liées au trafic, avec les modèles de qualité de l’eau, ne semble pas très pertinent dans l’objectif d’améliorer la prédiction de la contamination des eaux pluviales à l’exutoire. L’investigation à la micro-échelle du mécanisme de lessivage montre que les particules fines sont les plus susceptibles d’être mobilisées par le ruissellement. Cette étude a été menée en utilisant un simulateur de pluie innovant qui présente les avantages d’être mobile et léger, et la possibilité d’avoir des enregistrements en ligne du débit et de la turbidité. Les nouvelles connaissances acquises sur les processus soulignent une grande variabilité qui remet en cause l'intérêt de leur modélisation avec des approches déterministes. Ces connaissances sont intégrées à l’échelle du quartier pour développer un outil de modélisation conceptuelle basé sur une approche stochastique d'estimation de la concentration moyenne de MES et des paramètres de qualité. Le modèle développé est intégré dans le modèle hydrologique URBS. L’application de ce modèle permet d’intégrer la variabilité spatiale et temporelle des émissions en distinguant les contributions de chaque occupation du sol. Les résultats sont prometteurs en termes d’estimation des niveaux de concentration de MES à l’exutoire du bassin versant et de réplication du comportement général de la dynamique de MES, cependant des améliorations peuvent être envisagés pour consolider l’approche et améliorer ses prédictions. La comparaison de ce modèle avec des approches de modélisation empirique globale, conceptuelle semi-distribuée et physique distribuée, montre qu’en termes de pouvoir prédictif et de fiabilité, l’approche URBS-stochastique en parallèle avec l’approche de modélisation physique distribuée sont les plus performantes. En termes de simplicité d’implémentation et d’ajustement entre les observations et les simulations, les approches de modélisation empirique globale et conceptuelle semi-distribuée sont les plus puissantes. A l’issue de cette comparaison, il est clair qu’il n’existe pas un modèle parfait qui couvre toutes les caractéristiques de la modélisation de la qualité des eaux de ruissellement. Le choix de l’approche de modélisation la plus appropriée doit se faire en fonction des objectifs attendus par le modélisateur / Urban runoff contamination is recognized as a major source of the deterioration of the quality of surface water. Commonly used stormwater quality models have poor performance in predicting the pollutant dynamics at the surface outlet, mainly due to the lack of precise knowledge on the governing processes and the difficulties of acquiring representative and continuous databases on real sites. The main purpose of this Ph.D. thesis is to improve the state of stormwater quality modeling. It aims in particular to develop a conceptual modeling tool for stormwater quality prediction at the scale of a city district catchment, based on a deep understanding of the build-up and the wash-off. The application of commonly used stormwater build-up/wash-off models to simulate the dynamics of total suspended solids (TSS) at the outlet of the road catchment suggests that the models poorly replicate the temporal variability of the TSS concentrations unless short periods are considered. The unpredictable nature of the accumulation is largely responsible for the model failure. The evaluation of the contribution of atmospheric dry deposition to stormwater loads for polycyclic aromatic hydrocarbons (PAHs) and metals shows that atmospheric deposition is not a major source of contaminants in stormwater runoff. Thus, linking the air and water compartment in a modeling chain to have more accurate estimates of pollutant loads in stormwater runoff may not be relevant unless the direct traffic emissions are accounted for. The investigation of the wash-off process on elementary surfaces shows that the fine particles are the most likely to be mobilized and transported during a rainfall event. Stormwater samples were collected for this study using an innovative rainfall simulator that allows continuous, on-site monitoring of instantaneous flow and turbidity measurements and that can be easily transported and used on real sites. The new knowledge acquired on the build-up and wash-off processes underlines the great variability of these processes and calls into question their modeling with deterministic approaches. Hence, this knowledge is incorporated into developing a new conceptual stormwater quality model based on the stochastic drawing of event mean concentrations (EMC) of TSS and water quality parameters. The model is integrated within the hydrological model URBS. The application of this approach accounts for the spatial and temporal variability of pollutant emissions by distinguishing the contributions of each land use separately. The obtained results are promising in terms of estimating the concentration levels of TSS at the outlet of the city district catchment and replicating the general behavior of the TSS dynamics. However, improvements can be envisaged to consolidate the approach and improve its predictions. Comparison of this model with global empirical, semi-distributed conceptual and distributed physical modeling approaches shows that in terms of predictive power and stability, the stochastic-URBS and the physically distributed approaches are the most efficient. However, in terms of ease of implementation and best fit between observations and simulations, the global empirical and semi-distributed conceptual modeling approaches are the most powerful. This comparison shows that the perfect model that covers all aspects of stormwater quality modeling does not exist. The choice of the most appropriate modeling approach should mainly be driven by modeling objectives

148f. / Submitted by Ana Hilda Fonseca (anahilda@ufba.br) on 2013-03-22T17:35:21Z No. of bitstreams: 1 TESE VERSÃO FINAL_Rogete.pdf: 3403393 bytes, checksum: 8ad0a12697759237a2a80d8d5568a3c8 (MD5) / Approved for entry into archive by Ana Hilda Fonseca(anahilda@ufba.br) on 2013-04-19T14:20:42Z (GMT) No. of bitstreams: 1 TESE VERSÃO FINAL_Rogete.pdf: 3403393 bytes, checksum: 8ad0a12697759237a2a80d8d5568a3c8 (MD5) / Made available in DSpace on 2013-04-19T14:20:43Z (GMT). No. of bitstreams: 1 TESE VERSÃO FINAL_Rogete.pdf: 3403393 bytes, checksum: 8ad0a12697759237a2a80d8d5568a3c8 (MD5) Previous issue date: 2013 / CAPES / O material particulado atmosférico (MP) é um dos principais poluentes do ar, este pode ser emitido por fontes naturais e antrópicas. Em ambientes urbanos o tráfego de veículos é um dos grandes responsáveis por sua emissão. Em sua composição estão associadas inúmeras espécies químicas, dentre as quais se destacam metais e metalóides. A origem destas espécies através do tráfego está relacionada a várias fontes, tais como, produtos de combustão do combustível e óleo; produtos de desgaste de pneus, lonas de freio, rolamentos; materiais de construção das vias de tráfego; e ainda a ressuspensão da poeira do solo. As frações mais finas do MP são as mais nocivas e a exposição a estas partículas é responsável por vários efeitos à saúde e estão associadas ao aumento de riscos de doenças respiratórias e cardiovasculares e problemas reprodutivos. Especialmente os metais podem causar câncer, mutações e problemas neurológicos. Neste trabalho, as concentrações de partículas em suspensão foram determinadas por meio de técnica gravimétrica; e as concentrações atmosféricas dos elementos traço As, Ba, Ca, Cd, Co, Cu, Fe, Hg, Mg, Mn, Ni, Pb, Sb, Sn, V e Zn, nas frações MP10 e MP2,5 coletadas no Terminal Rodoviário da Lapa, foram determinadas usando as técnicas de ICP-MS e ICP OES. As amostras de MP10 e MP2,5 do ano de 2010, foram coletadas sobre filtros de microfibra de quartzo em amostradores de grande volume (Hi-Vol). As amostras de MP10 coletadas em 2005 em outro estudo, foram utilizadas neste trabalho com a finalidade principal de se investigar a composição elementar do MP no período de transição B0 (2005) para B5 (2010). Para a seleção do procedimento de extração, com vistas ao tratamento das amostras de MP, foram realizados alguns experimentos e dentre estes, a mistura de 2 mL HNO3, 1 mL de H2O2 e 5 mL H2O, se mostrou adequada produzindo respostas satisfatórias. A validação do método garantiu recuperações na faixa de 83% a 114%. Os limites de quantificação do método nas determinações realizadas por ICP-MS foram estabelecidos entre 0,02 e 1,82 ng m-3 e nas determinações por ICP OES entre 1,9 e 896 ng m-3. Os resultados da concentração de partículas em suspensão para MP10 e MP2,5, apresentaram valor médio, respectivamente, de 134 μg m-3 e 83,2 μg m-3. Entre os elementos traço minoritários, as maiores concentrações médias encontradas em 2010, foram para Hg, Ni, Pb, Sn e V cujos valores para MP10 foram, respectivamente, 4,52; 4,53; 7,33; 4,41 e 5,68 ng m-3; e para MP2,5 foram, respectivamente, 2,68; 3,01; 4,57; 1,32 e 2,96 ng m-3. Entre os elementos majoritários as maiores concentrações encontradas em 2010, foram para Ba, Ca, Fe e Mg, cujos valores médios foram, respectivamente, para MP10, 587; 5260; 5190 e 1907 ng m-3 e MP2,5, 165; 2759; 2101; 947 ng m-3. A avaliação das concentrações dos elementos traço por turno em 2010 mostrou que nos turnos da manhã e tarde em conjunto, a concentração dos elementos traço compreendeu aproximadamente entre 58% a 87% do total emitido na fração MP10; e entre 62% a 85% na fração MP2,5. Os cálculos do fator de enriquecimento revelaram que os elementos de origem antrópica no MP em suspensão, portanto considerados enriquecidos, foram As, Ba, Cd, Cu, Hg, Pb, Sb, Sn e Zn. A análise multivariada permitiu identificar os elementos que caracterizaram as emissões do MP e a influência do tráfego conforme os turnos de amostragem. E ainda indicou que as diferenças entre as frações MP10 de 2005 e 2010, correspondentes ao período de transição de B0 para B5, foram relacionadas às concentrações de Cd, Mn, Cu e Hg. / Salvador

252 f. / Submitted by Ana Hilda Fonseca (anahilda@ufba.br) on 2013-03-27T15:57:52Z No. of bitstreams: 1 Tese_Doutorado_Adriana_Moreno.pdf: 8730190 bytes, checksum: 56efa36bc67f97b073c9b56409edff28 (MD5) / Approved for entry into archive by Ana Hilda Fonseca(anahilda@ufba.br) on 2013-06-05T15:51:59Z (GMT) No. of bitstreams: 1 Tese_Doutorado_Adriana_Moreno.pdf: 8730190 bytes, checksum: 56efa36bc67f97b073c9b56409edff28 (MD5) / Made available in DSpace on 2013-06-05T15:52:00Z (GMT). No. of bitstreams: 1 Tese_Doutorado_Adriana_Moreno.pdf: 8730190 bytes, checksum: 56efa36bc67f97b073c9b56409edff28 (MD5) Previous issue date: 2012 / CAPES / O aporte de espécies químicas para a atmosfera representa importante mecanismo dos processos hidrogeoquímicos, tornando-se muito significativo na região semi-árida, que sofre continuamente com elevada frequência de períodos secos, além dos problemas socioeconômicos. Esta pesquisa objetivou estudar a influência do spray marinho na salinização das águas do Semi-Árido baiano. Amostragens de chuva e de material particulado atmosférico (MP) foram feitas em duas estações: Juazeiro, com águas subterrâneas salobras e Morro do Chapéu, com águas doces. Foram determinadas nas amostras de chuva concentrações de espécies inorgânicas, pH e condutividade. No MP foram avaliados os principais ions inorgânicos solúveis em partículas fracionadas por tamanho, utilizando um impactador em cascata, tipo Berner, de seis estágios: 0,06; 0,18; 0,55; 1,7; 4,9 e >14,9 μm. Isótopos estáveis do oxigênio-18 e deutério foram determinados na chuva como traçadores ambientais, analisados por espectrometria de massa, sendo avaliadas as razões Isotópicas (18O/16O e D/H). Ânions foram analisados por cromatografia iônica; NH3 por espectrofotometria molecular; Ca2+ e Mg2+ por espectrometria de absorção atômica com chama; Na+ e K+ por fotometria de chama. Os resultados obtidos mostraram na chuva de Juazeiro: pH entre 5,98 e 7,33, com média ponderada por volume (MPV) 6,80, sugerindo neutralização da acidez da chuva pela amônia ou por partículas básicas do solo, ou ainda, pelo spray marinho. A condutividade variou de 5,21 a 70,8 μS cm-1 e as concentrações molares médias iônicas, decresceram na seguinte ordem: Cl- > Ca2+ > NO3- > NH4+ > Na+ > K+ > Mg2+ > SO42- > H+. Em Morro do Chapéu o pH da chuva variou de 6,40 a 7,24, com MPV 6,75 e a condutividade de 4,58 a 19,1 μS cm-1. As concentrações molares médias iônicas decresceram na seguinte ordem: Cl- > NH4+ > Na+ > NO3- > Mg2+ > H+ > SO42- > K+ > Ca2+. Considerando as duas localidades, o nível de concentração das principais espécies inorgânicas no MP está na faixa de 13,6-26,9 nmol m-3 Cl-; 3,23-17,6 nmol m-3 NO3-; 2,87-11,0 nmol m-3 SO42- e 11,5-37,0 nmol m-3 Na+. O SO42- se distribui predominantemente na moda fina do MP atmosférico, indicando origem em transformações gás-partícula e/ou partícula-partícula. Cl- e Na+ se apresentam predominando na moda grossa, representando a contribuição do spray marinho. A técnica da análise de componentes principais (ACP) permitiu visualizar a influência marinha sobre as concentrações atmosféricas em ambas as estações, além de outras fontes (continentais naturais e antrópicas) exercendo controle sobre a atmosfera da região. Os resultados demonstram o potencial dos traçadores isotópicos determinados na chuva no entendimento do ciclo hidrológico na área de estudo: em Morro do Chapéu as águas de precipitação são na maior parte do tempo provenientes de locais mais distantes, enquanto que em Juazeiro, vem da própria região, embora frequentemente as massas de ar cheguem do litoral, mostradas pelas trajetórias reversas. A estimativa da contribuição do spray marinho na chuva é muito menor aí (56%) do que em Morro do Chapéu (92%). Apesar disso, em termos quantitativos pode-se concluir que a quantidade de spray marinho que chega à região é insuficiente para salinizar suas águas. Desta forma, a causa da salinização das águas em Juazeiro, deve ser atribuída à geologia local e aos processos de evaporação e concentração de sais. / Salvador

130 f. / Submitted by Ana Hilda Fonseca (anahilda@ufba.br) on 2013-08-19T12:56:49Z No. of bitstreams: 1 Tese João Victor da Silva Santos.pdf: 3782086 bytes, checksum: fc0dff19c6dd3fc0e31d7438b50efcba (MD5) / Approved for entry into archive by Ana Hilda Fonseca(anahilda@ufba.br) on 2013-08-19T13:00:29Z (GMT) No. of bitstreams: 1 Tese João Victor da Silva Santos.pdf: 3782086 bytes, checksum: fc0dff19c6dd3fc0e31d7438b50efcba (MD5) / Made available in DSpace on 2013-08-19T13:00:29Z (GMT). No. of bitstreams: 1 Tese João Victor da Silva Santos.pdf: 3782086 bytes, checksum: fc0dff19c6dd3fc0e31d7438b50efcba (MD5) Previous issue date: 2013 / CAPES / Este trabalho foi desenvolvido no âmbito do Instituto Nacional de Ciência e Tecnologia de Energia e Ambiente, com financiamento do CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico); e do projeto intitulado: “Estudo Multidisciplinar da Baía de Todos os Santos”, com financiamento da FAPESB (Fundação de Amparo à Pesquisa do Estado da Bahia). O objetivo foi determinar espécies metálicas presentes em MP emitido por motor estacionário do ciclo diesel acoplado a um sistema de dinamômetro, utilizando misturas de diesel/biodiesel, e também, em amostras ambientais coletadas em três localidades da Baía de Todos os Santos (BTS): Base Naval, Botelho e Itaparica. A quantificação das espécies metálicas foi realizada através de um Espectrômetro de massas com fonte de plasma (ICP-MS), em duas etapas: a extração assistida por microondas e a análise do extrato. Os parâmetros analíticos, como o limite de detecção, quantificação e precisão, se mostraram adequados para o propósito. A exatidão do método foi avaliada utilizando material de referência certificado NIST 1649a (poeira urbana). As recuperações obtidas alcançaram valores entre 74 a 104%. Para a coleta do MP2,5 oriundo do motor diesel, foram utilizados os seguintes combustíveis: B4, B50 e B100. As amostras foram coletadas em triplicata para cada combustível e as espécies Mn, Fe, Cu, Zn, Ba, Pb e Cr analisadas. Os resultados podem ser divididos em dois grupos. Um formado pelos elementos que reduziram suas concentrações com a adição do biodiesel (Mn, Fe, Cu, Zn e Pb) e outro formado pelos elementos que aumentaram sua concentração com a adição de biodiesel (Cr e Ba). Considerando o somatório das concentrações de todas as espécies estudadas, observa-se uma redução, à medida que mais biodiesel é adicionado à mistura. A redução foi de 26% quando comparado B50 com B4 e de 36 %, quando comparados B100 e B4. Nos sítios da BTS as amostras foram coletadas utilizando dois Hi-Vol (MP10 e MP2,5) e V, Mn, Fe, Co, Ni, Cu, Zn, Se, Mo, Cd, Ba, Cr e Pb foram quantificados. As concentrações das espécies metálicas analisadas nos sítios da BTS apresentaram valores inferiores ao máximo permitido para as espécies que possuem regulamentação na fração MP10 (Cd, Co, Cr, Mn, Ni e Pb). Sendo assim, as mesmas não representam risco iminente para a saúde humana. A comparação dos resultados obtidos para os sítios da BTS com outras localidades demonstram que os níveis tanto para a concentração das espécies metálicas, quanto para a massa de MP estão entre os menores encontrados na literatura. No entanto, as análises estatísticas (PCA e HCA) e de parâmetros como o fator de enriquecimento demostraram que boa parte das concentrações dessas espécies está relacionada a fontes antrópicas, podendo representar riscos futuros, à medida que a intensidade das emissões aumente. / Salvador

Les matières en suspension (MES) sont constituées de colloïdes et particules et sont couramment décrites comme des agrégats hétérogènes formées de phases minérales, organiques et biologiques et possédant une forte réactivité de surface. Cette étude vise à étudier l’évolution de composition spatiale et temporelle des MES de la rivière Moselle (Lorraine, France) et également d’étudier la réactivité des MES vis-à-vis de contaminants métalliques. Les MES ont été collectées à différentes stations le long de la rivière Moselle et selon différents régimes hydriques. Des études microscopiques et macroscopiques ont été réalisées dans le but de caractériser les MES. Les résultats ont montré que la composition minérale des MES était relativement constante (1) le long de la Moselle (2) durant différents régimes hydriques et que la géologie du bassin versant contribuait grandement à la composition des MES. Les affluents de la Fensch et de l’Orne, deux rivières impactées par l’héritage industriel ont cependant montré la présence de particules d’origine anthropique. Cette étude a également montré le rôle majeur des MES dans le transport des TMEs et REEs quel que soit le débit. La caractérisation organique des MES a également montré des variations atténuées révélant l’aspect intégrateur d’un bassin versant de cette taille. Des variations saisonnières ont tout de même été observées avec une production autochtone plus élevée durant l’été. L’augmentation du débit a engendré une diminution de la teneur en matière organique ainsi que la présence d’une matière organique plus dégradée. Hormis les stations sur la Fensch et l’Orne, les propriétés de surface des MES sont homogènes, en relation avec la composition des particules. Les études ont également montré que le zinc s’associait de manière différente selon la quantité de zinc en solution. Enfin, l’étude comparée du mode d’association du zinc sur les composés modèles et les MES naturelles a montré la contribution des phyllosilicates dans le transport du zinc / Suspended Particulate Matter (SPM) in rivers, are constituted of colloidal and particulate matter, and described as heterogeneous aggregates of mineral, organic and biological phases which display high and reactive surface area. This study aimed to investigate the spatial and temporal composition evolution (Mineral and organic) of SPM along the Moselle River (Lorraine, France). SPM were collected at different stations along the river and at different regime flow. Macroscopic and microscopic studies were performed in order to characterize natural SPM. The second objective was to investigate the reactivity of SPM toward metallic contaminants. The results showed that the grain size distribution, elemental composition and mineralogy of SPM along the Moselle River and during different regime flow showed only slight variations, except for the Fensch and Orne tributaries, two rivers that were impacted by inherited steel making industrialization and different land use. The results also revealed that the catchment geology greatly contributed to the SPM composition in the river and highlighted the fact that SPM play a high contribution in TMEs and REEs transportation. The SPM organic matter characterization also showed slight variations through the catchment revealing the diffuse pollution in a catchment of this size. Seasonal variations were observed with strong autochthonous production during low flow level in summer. Regime flow increase resulted in the decrease of TOC content and in the presence of more degraded OM. Except for Fensch and Orne stations, surface properties of SPM are similar in relation with SPM composition. This study also showed that Zn association mode differed with different Zn concentrations. The comparison between Zn association mode on lab controlled particles and natural SPM revealed the contribution of phyllosilicates in zinc transport