Made available in DSpace on 2015-03-13T17:10:45Z (GMT). No. of bitstreams: 1 RosanaSF.pdf: 1150257 bytes, checksum: 7b09ae850450d28e1241104be2965636 (MD5) Previous issue date: 2005-12-20 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / It s an application about the development of the family agriculture integrated to the market in which is detected the development of the relation of partnership between settled of agrarian reform and the capitalist enterprise. It s shown initially, a conceptual discussion about family agriculture, watching the historical contexts that characterize the expropriation and subordination of the category. This way, the family agriculture is contextual zed in the moment of the modernization of the agriculture, he rising of the social tension in the area of the restructuration of production and the globalization. Finding to understand the agrarian question in Rio Grande do Norte, it s characterized the acting of the state in promoting agrarian reform politics and redistribution of lands. This way, the research demonstrate the reality of the settled of Vale do L?rio, with the partnership of the Caliman Company S. A. in this context, it s emphasized the social geographic transformation in the settler. This way it was realized the analysis of the survey of data in a lot of public department, and the research of the area with use of application form, in 90% percent of the researched group, with interviewing with the leaders of this group and with the manager of the Company. The research demonstrates an analysis of the reality lived by this group, in the perspective the interests of the government and the capital. / Compreende um estudo acerca do desenvolvimento da agricultura familiar integrada ao mercado em que se destaca o desenvolvimento da rela??o de parceria entre assentados de reforma agr?ria e empresa capitalista. Para tanto, inicialmente ? exposta uma discuss?o conceitual sobre a agricultura familiar, perpassando pelo quadro hist?rico que caracteriza a expropria??o e subordina??o da categoria. Percorrido este caminho, a agricultura familiar ? contextualizada no momento da moderniza??o da agricultura, do aumento das tens?es sociais no campo, da reestrutura??o produtiva e da globaliza??o. Com o intuito de entender a quest?o agr?ria no Rio Grande do Norte, ? caracterizada a atua??o do Estado na promo??o de pol?ticas fundi?rias e da redistribui??o de terras. Nesse sentido, a pesquisa demonstra a realidade do assentamento Vale do L?rio, dada a efetiva??o da parceria com a empresa Caliman S. A. Nesse processo, se enfatizam as transforma??es socioespaciais no assentamento. Para isso, foi realizado o trabalho de gabinete, levantamento de dados em v?rios ?rg?os e o trabalho de campo com a aplica??o de formul?rios, em 90% das fam?lias assentadas, e da aplica??o de entrevistas junto aos presidentes das associa??es e administrador da empresa. A pesquisa resultou, dessa forma, numa an?lise da realidade vivida pelos assentados, dentro da perspectiva dos interesses do Estado e do capital

Este trabalho apresenta o estudo desenvolvido no Reservatório de Salto Grande (Americana, São Paulo) durante o período de agosto de 1996 a julho de 1997, para avaliar a taxa de sedimentação de material em suspensão alóctone que entra no reservatório pelo rio Atibaia (principal afluente) e pela área de entorno, bem como seus efeitos sobre as características físicas, químicas e biológicas do sistema e sua relação com o uso e ocupação da bacia hidrográfica, climatologia e mecanismos operacionais da barragem. Para tanto, foram selecionadas cinco estações de coleta considerando-se a morfometria do reservatório, nas quais foram colocadas, mensalmente, câmaras de sedimentação na proporção comprimento/diâmetro 3:1, a 30 e 70% da profundidade local, durante um período de 24 horas. Paralelamente à incubação, foram efetuadas medidas iniciais da temperatura, pH, condutividade, oxigênio dissolvido, penetração de luz, material em suspensão e nutrientes (nitrogênio e fósforo total), sendo que do material sedimentado foram quantificados os nutrientes totais e dissolvidos, material em suspensão (total, inorgânico e orgânico), clorofila a e feofitina. Os dados obtidos demonstram um gradiente de deposição de material em suspensão no sentido do rio Atibaia (Estação 1) para a barragem (Estação 5), com valores mais elevados no período chuvoso (taxa de sedimentação de 90,0 mg.cm -2 .dia -1 e 2,23 mg.cm -2 .dia -1 nas estações 1 e 5, respectivamente) em relação ao período seco (taxa de sedimentação de 6,0 mg.cm -2 .dia -1 e 1,0 mg.cm -2 .dia -1 nas estações 1 e 5, respectivamente). A maior contribuição do material em suspensão corresponde à fração inorgânica (entre 60 e 90%) em todas as estações no período chuvoso, sendo que no período seco a fração orgânica torna-se mais expressiva nas estações 3, 4 e 5 (aproximadamente 50%). A deposição de nitrogênio e fósforo total apresenta um comportamento semelhante ao do material em suspensão, com valores máximos nas câmaras de sedimentação incubadas a 70%. As taxas de sedimentação de nitrogênio variaram entre 0,1 a 1,0 mg N.cm -2 .dia -1 (estação 1, em julho e dezembro de 1996, respectivamente) e as de fósforo entre 4,0 e 50,0 µg P.cm -2 .dia -1 (estação 1, em julho e dezembro de 1996, respectivamente). Para as outras variáveis analisadas, também verificou-se as diferenças espacial (gradiente horizontal) e temporal, as quais foram mais acentuadas entre os períodos seco e chuvoso. Considerando-se os fatores que influenciam o processo de sedimentação, os principais foram a precipitação, a vazão, o tempo de residência da água e as atividades desenvolvidas na área de entorno do reservatório, com períodos diferenciados nas culturas existentes (principalmente a da cana-de-açúcar). Em relação as fontes de entrada de material alóctone, verifica-se que o rio Atibaia é o principal contribuinte, sendo que 90% desse material é depositado preferencialmente nas estações 1 e 2, formando um delta na entrada do reservatório. Os dados obtidos para taxa de sedimentação de material em suspensão e nutrientes (como fósforo e nitrogênio total), em comparação a outros sistemas, são considerados elevados, demonstrando o elevado processo de eutrofização, a perda dos usos múltiplos e a diminuição da vida útil do reservatório, bem como os impactos gerados pelas atividades antropogênicas desenvolvidas na bacia hidrográfica, influenciando a qualidade de água do sistema. / The present work shows the study developed in Salto Grande Reservoir (Americana-SP), from August 1996 to July 1997, to determine the sedimentation rate of allocthonous material, inputted in the reservoir by its main tributary (Atibaia river) and by the watershed, relationed with the physical, chemical and biological characteristics of the system and its relationship with the landuse, climatology and operational mechanisms of the dam. Five samplig stations were selected considering the reservoir morfometry, where sedimentation traps (aspect ratio 3:1) were incubeded monthly, at 30 e 70% of the local depht, during 24 hours. At the moment of incubation, water temperature, pH, conductivity, dissolved oxigen, light penetration, suspended matter and nutrients (total phosphorus and nitrogen) were measured. In the settled material, dissolved and total nutrients, suspended matter (total, inorganic and organic), chlorophyll a and phaeopigments were determined. The data shows a deposition gradient of the suspended matter from Atibaia river (sampling station 1) toward to the dam (sampling station 5), with higher values in rainy season (90,0 mg.cm -2 .day -1 and 2,23 mg.cm -2 .day -1 at station 1 and 5 respectively) compared with dry season (6,0 mg.cm -2 .day -1 and 1,0 mg.cm -2 .day -1 at station 1 and 5, respectively). The major contribution of the suspended matter is given by the inorganic component (60 to 90%) at all stations in the rainy season, however, in dry season the organic component became more expressive at stations 3, 4 and 5 (about 50%). The settling flux of total nitrogen and total phosphorus shows the same pattern of the suspended matter, with maximun values in the traps incubeded at 70%. The sedimentation rate for total nitrogen varied from 0,1 mg.cm -2 .day -1 to 1,0 mg.cm -2 .day -1 (sampling station 1, in July and December 1996, respectively) and for total phosphorus from 4 µg.cm -2 .day -1 to 50,0 µg.cm -2 .day -1 (sampling station 1, in July and December 1996, respectively). The main factors that influence the sedimentation process are precipitation, inflow, residence time of water and the different land use around the reservoir, mainly the sugar cane culture. Regarding to allochtonous material sources inputted in the reservoir, was observed that the principal contribution is from Atibaia river, settling about 90% of the suspended matter between station 1 and 2, where there is the formation of a delta. Sedimentation rate data for suspended matter and nutrients (total phosphorus and nitrogen), are considered very high when comparing with other systems, showing a increase on eutrofication process, lost of multiple uses and the siltation of the reservoir’s entry.

Entre le milieu du XIXème et du XXème siècle, le secteur sidérurgique a été l’une des principales sources de richesse en France. Toutefois, la production de ferromanganèse a généré une quantité considérable de déchets, notamment lors du lavage des fumées des hauts fourneaux. Ces boues d’épuration, riches en zinc (Zn), manganèse (Mn) et plomb (Pb) (5 à 40% en masse), ont été déposées dans des bassins de décantation en périphérie des sites sidérurgiques. Depuis la fermeture des usines, ces terrains sont restés en l’état et certains, comme à Pompey (Lorraine), ont été progressivement colonisés par la végétation. Compte tenu des risques sanitaires liés aux concentrations en métaux, une décontamination semble inévitable. Néanmoins, on prend conscience aujourd’hui de l’épuisement des ressources, et ces bassins apparaissent comme un gisement de ressources secondaires. Ce travail vise à développer un procédé hydrométallurgique pour extraire Zn, Mn et Pb de ces résidus, dans l’optique de récupérer ces métaux sous forme pure et revalorisable, tout en décontaminant ces sites. Tout d’abord, les expériences ont permis déterminer les conditions optimales (quantité d’acide, temps, température, ajout de réactifs, densité de pulpe) pour parvenir à extraire sélectivement Zn et Mn contenus dans les boues et former un résidu riche en Pb. Le Zn a été ensuite récupéré sous forme de ZnO ou ZnS par précipitation ou sous forme métallique par électrodéposition. Enfin, le Mn a été précipité sous forme de MnCO3 avec une concentration acceptable en impuretés. Une étude technico-économique a été réalisée pour évaluer l’intérêt de l’industrialisation du procédé / During the XIXth and XXth centuries, steel industry has been one of the main sources of wealth in France. However, ferromanganese manufacturing has produced huge quantities of wastes, for instance after blast-furnace gas washing. The residual sludge, containing high concentrations of zinc (Zn), manganese (Mn) and lead (Pb) (5 to 40 wt %), has been deposited in ponds, in the vicinity of steel-making plants. Since plant closure, these fields have been left untouched; some of them, like in Pompey (Lorraine) have been colonized by vegetation. These sites may be considered as a threat to health and environment and should be cleaned up. Nevertheless, with awareness of metal shortage, these ponds may be considered as deposits of secondary resources. This works aims at designing a hydrometallurgical process to extract Zn, Mn and Pb from these residues and recover them in a valuable form, while decontaminating the sites. At first, experiments have enabled us to determine the optimal conditions (acid concentration, duration, temperature, reactant addition, pulp density) to extract selectively Zn and Mn from the sludge and leave a Pb-rich residue. Then, Zn was recovered as ZnO or ZnS after precipitation or as Zn after electrowinning. Mn was recovered as MnCO3 at an acceptable purity. A technico-economic study has been done to assess the industrial interest of the process

The efficiency to improve the water quality of industrial and municipal wastewater in a constructed wetland/filter basin treatment system was investigated. The wetland system was constructed in a closed phosphate mine used for clay settling and sand tailings in Polk County, Florida. During 18-months of monitoring the chemical/microbiological composition of treated wetland water remained relatively constant, despite significant seasonal variations in temperature, rainfall and humidity. The following changes in water quality between input and output were observed: substantial decrease of water temperature (up to 10°C), reduction of As, SO4, F, Cl, NO3, NO2, Br, Na, K, Ca, and Mg, change in pH from 9 to 6.5-7, increase of H2S (up to 1060 micrograms/L), and a change from positive to negative ORP. There were no exceedances of the primary drinking water standards, volatile organic compounds, synthetic organic compounds, and radionuclides, but a number of exceedances for the secondary drinking water standards (Al, F, Fe, Mn, color, odor, total dissolved solids, and foaming agents). The concentration of fecal and total coliform bacteria in the wetland water was high, but subsequently reduced during filtration in the filter basin from 30 - 730 and 1000 - 7000 count/100 mL to < 2 and < 100 count/ 100 mL, respectively. To resolve the complex hydrogeological conditions a combined isotope/chemical mass-balance approach was applied. The results were the following: (1) the composition of water in the wetland varied throughout the period of the study; (2) a change in isotopic composition along the wetland flow path; (3) the wetland contained mainly wastewater (88 - 100 %) during normal pumping operations; however, hurricanes and inconsistent pumping added low conductivity water directly and triggered enhanced groundwater inflow into the wetland of up to 78 %; (4) the composition of water in monitor wells was mostly groundwater dominated; however periodically seepage from a water body to the north was detected; and (5) seepage from adjacent water bodies into the wetland was not identified during operation, which would indicate a potential water loss from the wetland. To test if the wetland system could be a prospective pre-treatment option for water used in aquifer storage and recovery (ASR) scenarios, a set of bench-scale leaching experiments was carried out using rocks from the Avon Park Formation, the Suwannee Limestone and the Ocala Limestone. Since As in the Floridan Aquifer was mainly present as an impurity in the mineral pyrite the elevated iron and sulfide concentrations in the wetland water were thought to prevent pyrite dissolution. The experiments which covered a range of redox conditions showed that the amount of As released from the aquifer matrix was not perfectly correlated with the bulk rock As concentration, nor the redox state of the water. The following important results were obtained: (1) the highest concentration of As was leached from the Avon Park Formation and the lowest - from the Suwannee Limestone, although the Ocala Limestone had the lowest bulk rock As; (2) minor to no As was released using native Floridan groundwater; (3) Tampa tap water, which chemically and physically resembled the ASR injection water, caused the As leaching of up to 27 micrograms/L, which was higher than the As drinking water standard; (4) the wetland and filter basin waters caused the highest release of As (up to 68 micrograms/L), which was unexpected because those water types were less oxygenated than Tampa tap water and thus should be less aggressive; (5) the in-situ filtration of the wetland water through a 0.2 micrometer membrane resulted in a reduction of As from 30 microgram/L to 16 microgram/L; and (5) the UV treatment significantly reduced both fecal and total coliform bacteria, but facilitated the increase of DO in initial waters, a change from negative to positive ORP, and the increase of As concentration in leachates. The experiments confirmed that perturbations of native aquifer conditions caused the release of As from the Floridan aquifer matrix, although the reaction may not be as simple as the dissolution of pyrite by oxygen, but additionally governed by a complex set of factors including the ORP of the system, SO4²?/S², Fe³?/Fe²?, dissolved organic carbon and microbial activity. In addition, the trend of As leaching could be governed by a set of factors, such as the porosity and permeability of the aquifer matrix influencing the rate and degree of free water saturation, amount of pyrite to be exposed to the preferential water flow paths, limited surface reactivity of pyrite with favored reactions on fractured mineral surfaces, the concentration and the selective leaching of As from individual pyrite crystals. To characterize and verify the geochemical processes in the column experiments, the Geochemist's Workbench reactive transport models (React and X1t) were developed. Results from the models correlated well to those from the column experiments and confirmed the following: (1) the water-rock reaction between the aquifer matrix and native groundwater was favorable for pyrite stability preventing the release of As into solution; (2) the injection of oxidizing surface water into reducing native groundwater caused a change in redox potential of the system thus promoting the dissolution of pyrite, and (3) 1D reactive transport model of water-rock reaction between the aquifer matrix and surface water indicated a diverse behavior of As along the column, such as the oxidative dissolution of pyrite, mobilization and simultaneous sorption of As onto neo-formed HFO, followed by the reductive dissolution of HFO and secondary release of adsorbed As, and the potential non-oxidative dissolution of pyrite contributing the additional source of As to the solution.

Although high rate algae ponds (HRAPs) are a proven wastewater treatment technology with numerous environmental, social, and economic benefits, their widespread use has been hindered by inconsistent and unreliable settling performance. Hence, the goal of this thesis is to investigate how specific operational parameters affect the settling performance of HRAPs. Nine HRAPs (30 m2 surface area, 0.3 m depth) were operated as three triplicate sets, with each set run on either a 2, 3, or 4 day HRT continuously from January 25, 2012 through April 11, 2013. Settling performance was determined (i) by measuring the TSS of Imhoff cone supernatant after 2 and 24 hours of settling and (ii) by measuring the TSS of tube settler effluent. Ponds operating on 2 - 3 day HRTs (loading rate was 24 - 36 g/m3-day csBOD5 and food to microorganism (F/M) ratio was 0.13 - 0.21 day-1) were able to settle consistently with residual TSS averaging less than 40 mg/L after 2 hours of settling time. Tube settlers showed potential as effective harvesting devices; ponds operating on a 2-day HRT averaged 27.9 ± 9.2 mg/L TSS in tube settler effluent at an overflow rate (OFR) of 9.4 L/min-m2. Microscopy analysis was performed and relationships were made between settling performance and algae dominance and floc structure.

No description available.

Deep-marine sandstones containing significant (> 10%) detrital mud (silt and clay) matrix have become increasingly recognized, but mostly in drill core or poorly exposed outcrops where details of their vertical and lateral variability are poorly captured. Exceptional vertical and along-strike exposures of matrix-rich and associated matrix-poor deposits in deep-marine strata of the passive margin Neoproterozoic Windermere Supergroup and foreland basin Ordovician Cloridorme Formation, provide an unparalleled opportunity to document such characteristics. In both study areas, strata form a 100s m long depositional continuum that at its upflow end consists of thick-bedded matrix-poor sandstone (<20% matrix) that transforms progressively downflow to medium- to thick-bedded muddy sandstone (20 – 50% matrix) to medium-bedded bipartite facies with a basal sandy (30 – 60% matrix) part overlain sharply by a muddier part (40 – 80% matrix), and then to thin-bedded sandy mudstone (50 – 90% matrix). This depositional continuum is then overlain everywhere by a thin- to very thin-bedded traction-structured sandstone and/or silty mudstone cap. This consistent lithofacies change is interpreted to reflect particle settling in a rapidly but systematically evolving, negligibly-sheared sand-mud suspension developed along the margins (Windermere) and downflow terminus (Cloridorme) of a high-energy, mud-enriched avulsion jet. Stratigraphically upward, beds of similar lithofacies type succeed one another vertically and transform to the next facies in the depositional continuum at about the same along-strike position, forming stratal units 2–9 beds thick whose grain-size distribution gradually decreases upward. This spatial and temporal regularity is interpreted to be caused by multiple surges of a single, progressively waning turbidity current, with sufficient lag between successive surges for the deposition of a traction-structured sandstone overlain by mudstone cap. Furthermore, the systematic backstepping or side-stepping recognized at the stratal unit scale in both the Windermere and Cloridorme is interpreted to be driven by a combination of knickpoint migration and local topographic steering of the flows, which continued until the supply of mud from local seafloor erosion became exhausted, the main channel avulsed elsewhere, or a new stratal element developed.

European iron production is to a large extent dependant on massive Kiruna type apatite-iron ore deposits. In this contribution, high-temperature magnetite samples from apatite-iron-oxide deposits are investigated by means of Electron Backscattered Diffraction. However, the origin of Kiruna-type deposits is still unresolved. Although magmatic processes are likely, it is not clear how small-scale processes can form giant Kiruna-type deposits. The sample suite consists of magnetite samples from six global apatite-iron-oxide deposits: the famous Kiirunavaara deposit and the Malmberget deposit, both located in northern Sweden, the Grängesberg deposit in south-central Sweden, the iconic El Laco deposit in north-eastern Chile, the Bafq deposit in central Iran, and the Varena deposit in south Lithuania. Fe-O systematics has been conducted to complement existing δ18O and δ56Fe isotope data and ensure magmatic origin of the samples from the Malmberget deposit (n=6) and the Varena deposit (n=2). This is the first effort to characterise magnetite samples from apatite-iron-oxide deposits utilising EBSD. In total, twelve EBSD maps have been produced. Evaluation of the EBSD data have been performed to quantify the preferred orientation of the magnetite crystals. Four deposits, with Kiirunvaara being the prime example, shows no preferred alignment of the magnetite crystals. Whereas the El Laco samples exhibits a strong preferred alignment of {111}. The EBSD data from magnetite samples in equilibrium with a magmatic source indicate that apatite-iron-oxide deposits are formed in both intrusive and extrusive environment and that magmatic crystal accumulation is a key process in aggregating magnetite to form large and even giant Kiruna-type deposits. / Europeisk järnmalmsproduktion är i stor utsträckning beroende av massiva apatit-järnmalmsfyndigheter av Kiruna-typ. I det här arbetet, undersöks magnetitprover av hög-temperaturs ursprung från olika apatit-järnmalmsfyndigheter med Elektron Bakåtspridande Diffraktion. Bildningsmekanismen av apatit-järnmalmsfyndigheter av Kiruna-typ är än idag oklar. Bevisen indikerar magmatiska bildningsprocesser, det är dock fortfarande oklart hur småskaliga magmatiska processer bildar gigantiska apatit-järnmalmsfyndigheter av Kiruna-typ. Provserien består av magnetitprover från sex globala apatit-järnmalmsfyndigheter: den världsberömda Kiirunavaara fyndigheten och Malmberget fyndigheten, båda lokaliserade i Norrbotten, Sverige, Grängesberg fyndigheten i Bergslagen, Sverige, den ikoniska El Laco fyndigheten i nordöstra Chile, Bafq fyndigheten i centrala Iran, och Varena fyndigheten i södra Litauen. För att fastställa ett magmatiskt ursprung och komplettera befintlig δ18O och δ56Fe isotopdata har Fe-O-systematik utförts på magnetitproverna från Malmberget (n=6) och Varena (n=2). Det här är den första dokumenterade EBSD-undersökningen av magnetitprover från apatit-järnmalmsfyndigheter. Totalt tolv EBSD-kartor har producerats. Utvärdering av EBSD-data har utförts för att kvantifiera den föredragna riktningen på magnetitkristallerna. I fyra fyndigheter, med Kiirunvaara som typexempel, uppvisar magnetitkristallerna ingen föredragen riktning, medan magnetitproverna från El Laco uppvisar en tydlig föredragen riktning längs {111}. EBSD-data från magnetitprover i jämnvikt med en magmatiskkälla påvisar att apatit-järnmalmer bildas i både intrusiva miljöer och extrusiva miljöer och att magmatisk ackumulation är en nyckelprocess för att aggregera magnetitkristaller och bilda stora till gigantiska apatit-järnmalmsfyndigheter av Kiruna-typ.

Testability is crucial in today’s complex industrial system on chips (SoCs), where sensitive on-chip analog voltages need to be measured. In such cases, an operational amplifier (opamp) is required to sufficiently buffer the signals before they can drive the chip pad and probe parasitics. A single-stage opamp offers an attractive choice since it is power efficient and eliminates the need for frequency compensation. However, it has to satisfy demanding specifications on its stability, input common mode range, output swing, settling time, closed-loop gain and offset voltage. In this work, the settling time performance of a conventional folded-cascode (FC) opamp is substantially improved. Settling time of an opamp consists of two major components, namely the slewing period and the linear settling period. In order to reduce the settling time significantly without incurring excessive area and power penalty, a prudent circuit implementation that minimizes both these constituents is essential. In this work, three different slew rate enhancement (SRE) circuits have been evaluated through extensive simulations. The SRE candidate providing robust slew rate improvement was combined with a current recycling folded cascode structure, resulting in lower slewing and linear settling time periods. Exhaustive simulations on a FC cascode amplifier with complementary inputs illustrate the effectiveness of these techniques in settling time reduction over all envisaged operating conditions.

Cette étude tente de modéliser les taux de transport de sédiments et l'évolution du lit dans un milieu estuarien complexe : l'estuaire de la Gironde, caractérisé par une grande hétérogénéité dans la composition des sédiments de lit, avec la présence de sédiments cohésifs et non-cohésifs ainsi que des mélanges sablo-vaseux. Notre objectif principal est d'étendre un modèle morphodynamique 2D développé par Huybrechts et al. (2012b) pour les sédiments non-cohésifs, afin de tenir compte de la présence de la vase et d'établir une étape préliminaire pour un modèle morphodynamique de sédiment mixte. Notre cadre est le système Telemac (version 6.1) où l'approche bi-dimensionnelle a été sélectionnée pour des simulations à grandes échelles spatiales (150 km) et moyen terme (5 ans).La première partie de ce travail est consacrée à la compréhension des processus de sédimentation-consolidation de la vase pure, en combinant expériences et modèles 1D verticaux. Les processus du sédiment cohésif sont ensuite intégrés dans le modèle morphodynamique de l'estuaire de la Gironde. Des expériences d'érosion et de dépôt ont été réalisées au laboratoire RWTH (Université d'Aachen, Allemagne) pour calibrer les paramètres des lois d'érosion et de dépôt. En outre, l'effet de la consolidation est pris en compte à travers la mise en œuvre d'un modèle 1DV de sédimentation et consolidation basé sur la théorie de Gibson (Thiébot et al., 2011) en utilisant des équations de fermeture analytique pour la perméabilité et la contrainte effective. Une attention particulière est accordée à l'initialisation de la structure verticale du lit sédimentaire. Les mesures et les résultats du modèle sont comparés pour les concentrations des sédiments en suspension et pour l'évolution de fond en moyen terme (5 ans).Dans la deuxième partie, un nouveau modèle 1DV pour la sédimentation entravée des mélanges sablo-vaseux a été développé sur la base des modèles de bi-disperse non-cohésifs. La solution numérique a été réalisée en prenant en considération un schéma de haute précision dans l'espace par la technique de reconstruction WENO et en temps par un Discontinue de Galerkin local (DG). Le modèle est ensuite validé par rapport à une large gamme de données expérimentales (mono-disperse sable, vase, non-cohésif bi-disperse et le mélange non-cohésif/cohesif) / This study attempts to model sediment transport rates and the resulting bed evolution in a complex estuarine environment: the Gironde estuary, characterized by a high hetereogeneity in the sediment bed composition, with the presence of both cohesive and non-cohesive sediments and sand/mud mixtures. Our main objective is to extend an existing 2D morphodynamic model developped by Huybrechts et al (2012b) for non-cohesive sediments, to account for the presence of mud and to draw some preliminary step for a fully mixte sediment morphodynamic model. Our framework is the finite element Telemac system (release 6.1), where the two-dimensional (depth averaged) approach has been selected for large scale and medium term simulations.The first part of this work is devoted to the understanding of sedimentation-consolidation processes for pure mud, combining laboratory experiments and 1D vertical models. Cohesive processes are then integrated in the 2D (depth-averaged) large scale morphodynamic model of the Gironde estuary developed by Huybrechts et al. (2012b). Erosion/deposition experiments were performed at the RWTH laboratory (University of Aachen, Germany) to calibrate the erosion and deposition law parameters. Moreover, the effect of consolidation is taken into account through the implementation of a 1DV Gibson-based sedimentation-consolidation model (Thiebot et al., 2011) using analytical closure equations for permeability and effective stress. Special attention is paid to the initialisation of the bed structure. Comparisons between measurements and model results are achieved on both suspended sediment concentration records and on medium term (5-year) bed evolutions.In the second part, a new 1DV model for the hindered settling of sand-mud mixtures has been developed based on the background of non-cohesive bi-disperse models. The numerical solution has been constructed by considering a high-order of accuracy in space via a Weighted Essentially Non Oscillatory (WENO) reconstruction technique and in time via a local space-time Discontinuous Galerkin (DG).The model is then validated against a large range of experimental data (mono-disperse sand, mud, non-cohesive bi-disperse and non-cohesive/cohesive mixture)