Les caractéristiques d’un espace, ses potentiels et ses contraintes varient selon les sociétés qui l’habitent ou le parcourent. L’appréhension d’un « territoire » − au sens d’espace approprié à une activité donnée et chargé d’identité − exige de préciser le rapport complexe des groupes sociaux au temps, qui est une donnée aussi peu homogène que l’espace auquel il se rapporte. On n’évoque pas là un temps uniquement historique ou calendaire, mais un temps que l’on pourrait qualifier de géographique tant il contribue à caractériser le territoire auquel il s’attache : d’où la notion proposée de « territoire-temps ».L’objectif est de considérer le rapport entre Temps et Territoire à partir de l’activité de pêche des communautés somono et bozo sur la partie encore peu étudiée du Niger supérieur. Le terrain de 600 kilomètres s’étend du village de Baro situé sur le Niandan en Guinée et lieu d’une pêche exceptionnelle en mare à la ville de Ségou au Mali, à l’entrée du delta intérieur. Dans des contextes à la fois ruraux mais aussi urbains − principalement celui de Bamako − cette recherche met à jour l’existence de maîtrises d’eau fluviales et lacustres qui instaurent des formes spécifiques d’organisation de pêches, collectives et individuelles.Quatre composantes principales, variables et croisées, sont à distinguer : l’inscription spatiale, les pratiques et techniques de pêche, les systèmes d’autorités et enfin les relations au symbolique et au religieux. Servant d’échelles réciproques de mesure et de construction du temps et de l’espace, elles sont constitutives d'une série de « territoires-temps » à l’échelle du Niger supérieur. / The characteristics of a given space, its potentials and restrictions, vary according to the social groups which live or travel there. The knowledge of a territory - i.e. a space dedicated to a specified activity loaded with identity - requires to clarify the complex relationship between social groups and time, which is a data as little homogeneous as the space it refers to. It is not a time only historical or calendar, but a time which could be called geographical since it much contributes to characterize the territory it is related to: hence this suggested notion of "territory-time".The aim is to study the relationship between Time and Territory, based on the Somono and Bozo communities' fishing activity in the rarely studied region of the Upper Niger. The 600 km field of research extends from the Baro village, on the Niandan River in Guinea, an exceptional pond fishing location, to the city of Ségou in Mali, at the entrance of the inner delta. In both rural and urban contexts  particularly in Bamako  this study reveals the control of river and lake waters which leads to specific forms of individual and collective fishing organisations.Four main components, variable and alternate, will be singled out: spatial inscription, fishing practises and techniques, authority systems, and finally symbolic and religious relationships. As reciprocal scales to measure and build time and space, they lead to several "territories-time" in the Upper Niger area.

Au Niger, la maîtrise des ressources en eau demeure toujours un défi majeur après plus de 50 ans de politique hydraulique. Les investissements réalisés durant la Décennie Internationale de l’Eau Potable et de l’Assainissement (1981-1990) et les Objectifs du Millénaire pour le Développement (2000-2015) n’ont pas pu couvrir les besoins énormes en eau. Le déficit en infrastructures se pose au niveau de toutes les composantes du secteur de l’hydraulique. Les besoins en eau de plus en plus croissants et l’insuffisance des investissements publics pour y faire face expliquent ce sous-équipement en infrastructures hydrauliques. Au niveau de la commune urbaine de Téra, au-delà de la forte croissance démographique et de l’insuffisance des investissements dans le secteur de l’eau, il faut ajouter les contraintes climatiques et hydrogéologiques dans l’analyse de la situation hydraulique. Dans la ville de Téra, la précarité hydrique est due à un déficit considérable de production d’eau et à un réseau de distribution d’eau inadapté au site de la ville. Ainsi, de décembre à août, les trois quarts de la ville, principalement les quartiers Carré, Résidence, Douane, TP et Guenobon restent sans être desservis en eau. En milieu rural, l’insuffisance des points d’eau, leur localisation par rapport aux villages et le temps de rétention assez court (3 à 4 mois) des plans d’eau entraînent une situation d’extrême précarité hydrique qui bouleverse la vie socio-économique. En ville comme en campagne, en dépit des différences territoriales et des modalités d’accès à l’eau, les populations vivent le même niveau de précarité hydrique et y apportent les mêmes types de solutions. Elles recourent ainsi aux points d’eau traditionnels et développent une solidarité hydraulique à travers la mutualisation des points d’eau entre quartiers, entre villages et entre ville-villages. Mais, avec cette situation hydraulique particulièrement précaire réduisant systématiquement la pratique des activités économiques et la satisfaction des besoins humains fondamentaux, les défis de développement local deviennent de plus en plus lourds pour la commune urbaine de Téra. / In Niger, water resource management remains a major challenge after more than 50 years of water policy. Thus, the investments carried out during the International Decade of Driking Water and Sanitation (1981-1990) and the Millennium Development Goals (2000-2015) could not meet the enormous needs of water. The infrastructure deficit is being faced by all components of the hydraulic sector. The growing demand for water and insufficient public investment to meet it explain this under-equipment in water infrastructure. At the level of the urban district of Tera, in addition to the strong demographic growth and insufficient investments in the water sector, climatic and hydrogeological constraints must be added to the analysis of the hydraulic situation. In the city of Tera, the hydrous precariousness is due to a considerable lack of water production and an inadequate water distribution network at the city site. Thus, from december to august, three-quarters of the city, mainly the Carré, Résidence, Douane, TP and Guenobon neighbourhoods remain underserved. In rural areas, the insufficiency of water supply points, their location in relation to villages to the villages and the rather short time of retention (3 à 4 months) of lakes defines a situation of extreme hydrous precariousness which affects the socio-economic life. In town as in the countryside, despite the territorial differences and water access methods, the populations face the same level of hydrous precariousness and adopt the same types of solutions. Thus, they resort to the traditional water supply points and develop a hydraulic solidarity through the mutualisation of water supply points between districts, villages, villages and city. However, with this particularly precarious hydraulic situation systematically reducing the practice of economic activities and the satisfaction of the fundamental human needs, the challenges of local development become increasingly heavy for the urban district of Tera.

Il est admis dans les théories économiques que l’existence de risques importants peut être source de sérieuses perturbations au bien-être des ménages et à l’équilibre budgétaire de l’Etat, car les risques ne permettent pas souvent l’optimisation des ressources. En admettant que le risque est un produit d’aléa et de vulnérabilité, nous constatons que l’aléa est souvent considéré au Niger comme l’unique «coupable» de ces perturbations, alors que le comportement des agents face au risque peut en être un facteur déterminant. Sur ce constat, cette thèse se propose d’analyser ces comportements et leurs implications dans les décisions économiques des ménages. Les principaux résultats montrent d’abord une aversion au risque assez relative qui s’explique par deux approches dominantes: une perception fataliste des risques naturels et anthropiques d’une part, et une rationalité adaptative au regard de l’importance de ces risques et de la vulnérabilité des ménages, d’autre part. Cette notion d’aversion a été ensuite utilisée pour servir de lien à l’analyse des risques de comportement inhérents essentiellement à l’asymétrie d’information. Il ressort de cette analyse que face aux risques naturels auxquels les individus paraissent impuissants, ces derniers développent des comportements opportunistes au détriment des contrats de crédit mutuellement avantageux, par un usage abusif de la rente informationnelle. Nous pensons que dans ce cas-ci, la contrainte des incitations doit être sérieusement prise en compte. Par ailleurs, la simultanéité des risques climatiques et d’une forte asymétrie d’information en milieu rural laisse penser que l’assurance agricole indicielle doit être progressivement envisagée. / It is recognized in economic theory that the existence of significant risks can cause serious disruption to the well-being of households and to the State budget’s balance, because the risks do not often value for money. Assuming that the risk is a hazard and vulnerability occurs, we find that the hazard is often seen in Niger as the only "guilty" of these disturbances, while the agents' behavior towards risk can be a factor. On this observation, this thesis proposes to analyze these behaviors and their implications in the economic decisions of households. The main results first show a rather relative risk aversion, which can be explained by two main approaches: a fatalistic perception of natural and man-made hazards on the one hand, and adaptive rationality in terms of the importance of these risks and the vulnerability of households, on the other. This notion of aversion was then used to provide a link to the analysis of risk behavior associated with information asymmetry. It is clear from this analysis, to natural hazards which individuals appear powerless; they are developing opportunistic behavior at the expense of credit agreements mutually beneficial, by abuse of informational rent. We believe that in this case, the incentive constraint must be taken seriously. The simultaneity of climate risk and high information asymmetry rural index suggests that the agricultural insurance should be progressively considered.

Résumé Ce travail est un premier pas dans l’étude de la qualité des eaux du fleuve Niger à Niamey. Il est basé sur la physico-chimie et les macroinvertébrés de cet écosystème aquatique. L’approche physico-chimique met en évidence les changements de la qualité des eaux, le long des rives, en relation avec les rejets de la ville et en fonction du régime du fleuve. L’impact de ces rejets est très négligeable à l’échelle de l’écosystème à cause de la forte dilution. La demande chimique en oxygène, l’oxygène dissous, l’ammonium, les orthophosphates et le phosphore total sont les principaux facteurs environnementaux qui déterminent la pollution des eaux liée aux matières organiques et oxydables, aux matières azotées et phosphorées dans ce fleuve. L’étude des macroinvertébrés fait ressortir 83 taxons répartis le long du fleuve Niger à Niamey. La description des peuplements de macroinvertébrés montre une variation de structure des communautés, en passant de l’amont à l’aval des points de rejets, caractérisée par une baisse de la richesse et de la diversité taxonomique en aval immédiat des rejets. La présence, dans certaines stations en aval immédiat des rejets, des taxons tels que Chironomus gr. plumosus, Melania sp., les familles des Syrphidae et des Culicidae, est une indication de la dégradation de la qualité des eaux liée à la matière organique. Par contre, les taxons comme Thraulus sp., Elassoneuria sp., Afronurus sp., Centroptiloides sp., Adenophlebia sp., Dipseudopsis sp. et Neoperla sp., appartenant aux Ephéméroptères, Trichoptères et Plécoptères, reflètent une meilleure qualité de l’eau dans les stations de référence situées en amont de tous les points de rejets. L’importante diversité de la famille des Chironomidae (20 taxons) dans ce cours d’eau offre de bonnes perspectives pour son utilisation dans l’étude de la qualité des eaux du fleuve Niger à Niamey. Les descripteurs qui expliquent significativement la distribution des communautés de macroinvertébrés le long du fleuve Niger à Niamey sont la matière organique (demande chimique en oxygène) et les nutriments (ammonium, orthophosphates et phosphore total). La technique d’échantillonnage au filet troubleau explique beaucoup plus d’inertie que les substrats artificiels. Quant à la jacinthe d’eau, elle présente peu d’intérêt dans l’étude de la qualité des eaux du fleuve Niger à Niamey à cause de sa présence uniquement en période de crue. Summary This survey is a first step in the study of water quality of the River Niger in Niamey. It is based on physicochemical factors and the macroinvertebrates inhabiting this aquatic ecosystem. The physicochemical approach underlines the changes in water quality, along the banks, in relation with wastewater from the city of Niamey, and as a response to seasonal variations of water level. The impact of wastewater on the scale of the entire ecosystem appears very limited, because of the strong dilution. Chemical oxygen demand, dissolved oxygen, ammonium, phosphates and total phosphorus levels are the main environmental factors that determine both the pollution due to organic (and oxidizable) matter, and the pollution resulting from nitrogen and phosphorus-based chemicals in this river. In this survey 83 taxa of macroinvertebrates were found along the River Niger in Niamey. The description of macroinvertebrates shows a variation of community structure, from upstream to downstream, that is characterized by a decrease of taxonomic richness and diversity downstream wastewater discharges. The presence of Chironomus gr. plumosus, Melania sp., families of Syrphidae and Culicidae indicates a deterioration of water quality due to organic matter in some stations near wastewater discharges. However, taxa like Thraulus sp., Elassoneuria sp., Afronurus sp., Centroptiloides sp., Adenophlebia sp., Dipseudopsis sp. and Neoperla sp. reflect a better quality of water in the reference stations located upstream of all wastewater discharges. The high diversity of Chironomidae (20 taxa) in this river makes them a good candidate taxonomic group to be used for the assessment of water quality in the River Niger near Niamey. The factors which significantly explain the distribution of macroinvertebrates communities along the River Niger in Niamey are organic matter (chemical oxygen demand) and nutrients (ammonium, phosphates, total phosphorus). Results from net hand samples explain a higher fraction of total inertia than the ones obtained using artificial substrata. Water hyacinths play a limited role in the survey of water quality in the Niger near Niamey, because they are only present during floodperiods.

Texte remanié de: Master--Sciences politiques--Dijon--Université de Bourgogne, 2006. / Bibliogr. p. 283-286. Notes bibliogr.

Made available in DSpace on 2016-06-02T18:57:44Z (GMT). No. of bitstreams: 1 4824.pdf: 1850234 bytes, checksum: 145b88dba921504ea587a0ecf7661801 (MD5) Previous issue date: 2012-06-29 / Universidade Federal de Sao Carlos / The aim of the search was evaluate alternatives to accelerate the solubilization of minerals contained in rock powder. In the first experiment, presented in Chapter 2, the objective was to evaluate the effect of the fungus Aspergillus niger strain CCT4355 and vinasse in the solubilization of minerals contained in the basalt powder. The experiment in vitro consisted in the treatments: vinasse + A. niger (VF), rock powder + vinasse (PV) and rock powder + vinasse + A. niger (PVF). The basalt powder used had grains smaller than 0.053 mm. In PV the solubilization of calcium, magnesium, potassium, zinc and copper was greater than PVF, demonstrating the potential of vinasse as solubilizing agent. It concludes that mixtures of vinasse and rock powder have significant potential for production of low cost biofertilizer. In the second experiment, presented in chapter 3, the objective was to evaluate the effect of A. niger in the release of nutrients from the powder of basalt and phonolite in vitro dissolution tests. The treatments were: powder of phonolite + medium (FM), powder of phonolite + medium + fungus (FMA), powder of basalt + medium (DM), powder of basalt + medium + fungus (DMA) and fungus + medium (MA). It was observed that A. niger was able to produce organic acids which solubilized the rock powders and interacted in different ways with the nutrients. It is concluded that the strain CCT4355 of A. niger has potential as a solubilizing agent of silicate rock powder. The chapter 4 presents the results obtained with mixtures of vermicompost and basalt powder, and the two objectives were: i) determine the availability of nutrients in bioproduct resulted of vermicompost, prepared with viii the addition of powder of basalt, and ii) evaluate the effect of rock powder, with and without vermicomposting, in short cycle culture, using Italian zucchini (Cucurbita pepo) as a indicator plant. The application of basalt powder in the vermicompost layers provided the pH raising of the product obtained at the end of 55 incubation days, but the vermicomposting was not able to provide nutrients presents in the basalt powder. The application of vermicompost, with and without addition of rock powder, had an effect statistically similar to conventional fertilization, confirming the importance of vermicomposting in production system with restricted access to industrialized products. It is concluded that vermicomposting did not increase the release of nutrients contained in the basalt powder when prepared and applied in a Italian zucchini. It is hoped that this research contributes to a better understanding of stonemeal as an alternative practice for soil fertilization. / Objetivou-se com a pesquisa avaliar alternativas para acelerar a solubilização de minerais contidos em pó de rocha. No primeiro ensaio, apresentado no capítulo 2, o objetivo foi avaliar o efeito do fungo Aspergillus niger linhagem CCT4355 e vinhaça na solubilização de minerais contidos em pó de basalto. O experimento in vitro consistiu nos tratamentos: vinhaça + A. niger (VF), pó de rocha + vinhaça (PV) e pó de rocha + vinhaça + A. niger (PVF). O pó de basalto utilizado possuía grãos de tamanho inferior a 0,053 mm. Em PV a solubilização de cálcio, magnésio, potássio, zinco e cobre foi maior do que em PVF, evidenciando o potencial solubilizador da vinhaça. Conclui-se que misturas de vinhaça e pó de rocha possuem importante potencial para produção de biofertilizante de baixo custo. No segundo experimento, apresentado no capítulo 3, o objetivo foi avaliar o efeito de A. niger na liberação de nutrientes dos pós de basalto e de fonolito em ensaios de solubilização in vitro, utilizando meio de cultura líquido adaptado para A. niger. Os tratamentos adotados foram: pó de fonolito + meio (FM), pó de fonolito + meio + A. niger (FMA), pó de basalto + meio (DM), pó de basalto + meio + A. niger (DMA) e A. niger + meio (MA). Observou-se que A. niger foi capaz de produzir ácidos orgânicos que solubilizaram os pós de rocha e interagiram de diferentes formas com os nutrientes. Conclui-se que A. niger tem potencial como solubilizador de pó de rochas silicáticas. O capítulo 4 apresenta os resultados obtidos com misturas de vermicomposto e pó de basalto, e foram dois os objetivos: i) determinar a disponibilidade de nutrientes em bioproduto resultante da vermicompostagem, preparada com adição de pó de basalto, e ii) avaliar o vi efeito de pó de rocha, com e sem vermicompostagem, em cultura de ciclo curto, utilizando abobrinha italiana (Cucurbita pepo) como planta indicadora. A aplicação de pó de basalto nas camadas do vermicomposto proporcionou elevação do pH do produto obtido ao final de 55 dias de incubação, mas a vermicompostagem não foi capaz de disponibilizar nutrientes presentes no pó de basalto. A aplicação de vermicomposto, com e sem adição de pó de rocha, teve efeito semelhante à adubação convencional, confirmando a importância da vermicompostagem em sistema de produção de acesso restrito a insumos industrializados. Conclui-se que a vermicompostagem não promoveu aumento na liberação de nutrientes contidos no pó de basalto quando preparada e aplicada em cultura de abobrinha italiana. Espera-se com essa pesquisa contribuir para o melhor entendimento da rochagem como prática alternativa para a fertilização de solos.

Made available in DSpace on 2016-08-17T18:39:35Z (GMT). No. of bitstreams: 1 3281.pdf: 2858153 bytes, checksum: 9041de7a1d28d8aaa5e4978013406e33 (MD5) Previous issue date: 2010-10-14 / The açaí agroindustry is the most important productive chains in northern Brazil. The residues in the marketing of açaí consists mainly of its pits, which are discarded in landfills and waterways without any treatment. A possible application to açaí pits is its use as substrate for solid state fermentation (SSF) for the production of lignocellulolytic enzymes as CMCase and xylanase, which act in the conversion of lignocellulosic materials into fermentable sugars. Currently, the cost of production of these enzymes has emerged as the biggest obstacle to the use of agro-industrial waste and the process of SSF gained prominence in this context due to several advantages over other technologies. The SSF process presents a large number of variables that affect the production of metabolites of interest, highlighting the sources of carbon and nitrogen, inducing growth and mineral salts. This study aimed to evaluate the use of pits of açaí as substrate for enzyme production by SSF evaluating the influence of the composition of culture medium for SSF through application of the methodology of statistical design full factorial 24 for selection of significant variables. The variables studied were the initial medium moisture and the concentrations of meat peptone extract, yeast extract, and CMC. After extraction of the enzyme complex and quantification of CMCase and xylanase activities, the variables of concentration of meat peptone extract and yeast extract were significant for enzyme production. Subsequently, a central composite rotatable design (CCRD) was made to achieve the optimization of the process parameters. The highest activities were obtained by increasing the concentration of meat peptone extract and yeast extract, reaching 8.24 U g-1 and 8.08 U g-1, to CMCase and xylanase, values, respectively. Additional tests were made at concentrations three times higher than those used at the midpoint of the CCRD, which indicated an increase of 1.59 and 1.16 times in the enzymatic activities of CMCase and xylanase, respectively. However, by Tukey test, these increases did not differ statistically in comparison to the tests results obtained using concentrations of reagents encoded at +1.41, giving economic advantage to the tests made with smaller amounts of reagents. The pit of açai has shown promising as a substrate for SSF, but additional studies are performed to define and optimize the process parameters. / A agroindústria do açaí é uma das cadeias produtivas mais importantes da região Norte do Brasil. O excedente da comercialização do açaí é constituído principalmente de seus caroços, os quais são descartados em aterros sanitários e cursos d água, sem qualquer tratamento. Uma possível aplicação para o caroço do açaí é sua utilização como substrato para fermentação no estado sólido (FES) para a produção de enzimas lignocelulolíticas, como CMCases e xilanases, as quais atuam na conversão de materiais lignocelulósicos em açúcares fermentescíveis. Atualmente, o custo de produção destas enzimas tem se apresentado como o maior entrave para o aproveitamento dos resíduos agroindustriais e o processo de FES ganha destaque neste contexto por apresentar algumas vantagens sobre outras tecnologias. No processo de FES um grande número de variáveis afeta a produção de metabólicos de interesse, destacando-se as fontes de carbono e nitrogênio, indutores de crescimento e sais minerais. Assim, este trabalho teve como objetivo utilizar o caroço do açaí como substrato para a produção de enzimas por FES avaliando-se a influência da composição do meio de cultivo através da aplicação da metodologia de planejamento estatístico fatorial 24 completo para seleção das variáveis significativas. As variáveis estudadas foram a umidade inicial do meio e as concentrações de extrato de peptona de carne, extrato de levedura e CMC. Após a extração do complexo enzimático e quantificação das atividades da CMCase e xilanase, as variáveis concentração de extrato de peptona de carne e extrato de levedura mostraram-se significativas para a produção enzimática. Posteriormente, buscou-se a otimização dos parâmetros do processo através de um delineamento composto central rotacional (DCCR). As maiores atividades foram atingidas com o incremento da concentração de extrato de peptona de carne e extrato de levedura chegando a 8,24 U g-1 e 8,08 U g-1, de CMCase e xilanase, respectivamente. Testes complementares foram feitos em concentrações 3 vezes maiores que as utilizadas no ponto central do DCCR, os quais indicaram um aumento de 1,59 e 1,16 vezes nas atividades enzimáticas da CMCase e xilanase, respectivamente. Porém, através do teste de Tukey, estes aumentos não apresentaram diferença estatística em relação aos resultados obtidos nos ensaios utilizando concentrações de reagentes ao nível codificado +1,41, conferindo vantagem econômica aos ensaios feitos com menores quantidades de reagentes. O caroço do açaí mostrou-se promissor como substrato para FES, porém novos estudos devem realizados visando à definição e otimização dos parâmetros do processo.

Os compostos fenólicos estão presentes em grande número de efluentes industriais, cujos lançamentos inadequados podem acarretar em riscos ao meio ambiente e à saúde humana. O uso de fungos em reatores biológicos é uma alternativa de tratamento de despejos que possuem compostos persistentes, como fenóis. O objetivo deste trabalho foi estudar a viabilidade do uso de Aspergillus niger em reator biológico para o tratamento de água residuária sintética contendo fenol. O trabalho foi realizado com dois tipos de reatores: em batelada e reatores contínuos com escoamento ascendente. No experimento em batelada, foram utilizados 5 reatores de controle (RC), 5 com fungos (RF) e 5 com fungos e glicose (RFG), verificando-se o uso de glicose (5 g/L), como substrato primário, e a remoção do fenol pelos fungos. Estes apresentaram maior desenvolvimento nos reatores contendo glicose (RFG), alcançando-se remoção de 100% de fenol, no quinto e último dia de experimento. Nestes reatores, a velocidade média de consumo de fenol foi quase o dobro da desenvolvida nos reatores sem glicose (RF). A remoção de matéria orgânica, medida como DQO, foi superior nos reatores contendo glicose (RFG) e atingiu 93%, no quinto dia. Não houve remoção significativa de fenol nos reatores de controle. Nos RF, as maiores remoções de fenol e matéria orgânica foram registradas no quinto dia e foram, respectivamente, de 48% e 27%. As maiores remoções de fenol em relação à de matéria orgânica indicam, possivelmente, a presença de compostos intermediários da degradação do fenol. Os reatores contínuos, cada um com volume total de 4,45 L e com meios suportes de manta de polipropileno (R1) e espuma de poliuretano (R2), foram mantidos sob as mesmas condições operacionais, durante 399 dias, divididos em três tempos de detenção hidráulica: 8 h, dividido em duas fases de alimentação (Fase I – alimentação complementada com glicose e Fase II – alimentação sem complementação de glicose); 4 h e 6 h. As maiores remoções de fenol ocorreram durante o tempo de detenção hidráulica (TDH) de 8 h, tanto com a presença ou não de 0,5 g/L de glicose no afluente, obtendo-se, na Fase I, remoções médias de fenol de 99,5% '+ OU -' 2 (R1) e de 98% '+ OU -' 5 (R2) e, na Fase II, 99,6% '+ OU -' 1(R1) e 92% '+ OU -' 23 (R2). No tempo de detenção hidráulica de 4 h, a remoção média de fenol ficou em torno de 50%, em ambos os reatores. Com o tempo de detenção hidráulica de 6 h, houve melhora na eficiência de remoção, atingindo 72% '+ OU -' 35 (R1) e 78% '+ OU -' 25 (R2). Análises microscópicas revelaram que os fungos cresceram bem nos suportes empregados, porém o uso de espuma de poliuretano provocou maiores problemas operacionais. Apesar dos bons resultados de remoção de matéria orgânica e de fenol, houve crescimento excessivo de biomassa no interior dos reatores contínuos, o que resultou na colmatação do leito, indicando necessidade de se procurar melhor ajuste nutricional do meio para controlar a geração de biomassa. / The phenolic compounds are present in a great quantity in industrial effluents, which inappropriate release can cause serious damage to the environment and to human health. The usage of fungi in biological reactors is an alternative to the treatment of wastes that contain compounds with persistent nature like phenol. The goal of this work was the study of the available usage of Aspergillus niger in a biological reactor treating synthetic wastewater containing phenol. The work was realized in batch and upflow continuous reactors. Five control reactors (CR) were applied in the batch experiment, being five with fungi (FR) and five with fungi and glucose (GFR), in order to verify the application of glucose (5 g/L) as main substrate and the removal of phenol by fungi. These presented better development in the reactors containing glucose, with the achievement of 100% of phenol removal in the fifth and last day of the experiment. In these reactors, the mean consumption velocity of phenol was approximately the double of those that were developed in the reactors without glucose. The organic matter removal (measured as COD) was higher in the reactors containing glucose, achieving 93% in the fifth day. There was no significant phenol removal in the control reactors. The higher removals of 48% for phenol and 27% for organic matter were observed in the RF reactors in the fifth day, indicating the possible presence of intermediate compounds in the phenol degradation. The continuous reactors were built with total volume of 4,45 L each one, with polypropylene blanket as support media in the R1 reactor and polyurethane foam as support media in the R2 reactor. The reactors were kept in the same operational conditions during 399 days. These conditions were divided in three hydraulic detention times (HDT): 8 h, divided in two feeding phases (Phase I – feeding complemented with glucose and Phase II – feeding without complementation of glucose); 4 h and 6 h. The higher phenol removals occurred during the hydraulic detention time of 8 h, in the presence and absence of 0,5 g/L of glucose in the influent. The mean phenol removals of 99,5% '+ OU -' 2 (R1) and 98% '+ OU -' 5 (R2) were attained in the Phase I, and 99,6% '+ OU -' 1 (R1) and 92% '+ OU -' 23 (R2) in the Phase II. The mean phenol removal was around 50% in both reactors when hydraulic detention time of 4 h was applied. With the hydraulic detention time of 6 h, there was improvement in the removal efficiency that achieved 72% '+ OU -' 35 for R1 reactor and 78% '+ OU -' 25 for R2 reactor. The microscopic analyses showed that fungi grew well in the applied support media, but the usage of polyurethane foam caused more operational problems. Even with the good results of the organic matter and phenol removals, there was excessive growth of biomass inside the reactors. This resulted in the clogging of the blanket, indicating the necessity of better nutritional adjustment of the media to control the biomass generation.

Doctorat en Sciences / info:eu-repo/semantics/nonPublished

The nascency of an oil state is characterized by talking oil politics. In this oil talk, the travelling idea of the resource curse takes center stage in speech acts of naming, blaming and claiming to question the legitimacy of political opponents. Conducting a situational analysis, this article focuses on the public political debate about oil in Niger’s media landscape before, during and after the oil refinery’s inauguration ceremony in Zinder in late 2011. I situate the actors’ oil talk according to their positions in the political arena to reveal their hidden transcripts. By doing so, I will show that the oil talk is enacted in a double sense. First, it is the political actors’ scripts that shape the very articulation of their oil talk in a context of political competition in a multi-party system. Second, the oil talk is enacted through an actor-network of media technologies and political players’ access privileges that allow some to articulate their political views whereas others lack the means to do so. I use these findings to discuss the impact of new media in Nigerien politics and to decode the ‘how’ of Nigerien politics itself.