O estudo dos fatores intervenientes, micro e macropropriedades dos lodos de estação de tratamento de água (ETA), no desaguamento por sistemas naturais, com uso de leito de drenagem, constituiu o principal foco desta pesquisa. Assim, ensaios de desaguamento por leito de drenagem foram realizados com amostras de lodos de sulfato de alumínio e de cloreto de polialumínio (PA\'CL\') e monitoramento das variáveis climáticas. Os resultados comprovaram o desempenho do leito de drenagem para redução de volume, da ordem de 80% e 90% para os lodos de PA\'CL\' e sulfato de alumínio e teor de sólidos final respectivamente de 30 a 90%, sem consumo de energia. Na fase de drenagem, independente do tipo e volume de lodo aplicado, a vazão de drenagem foi maior quanto menor o valor da taxa de aplicação de sólidos - TAS (Kg/\'M POT.2\') (fração volumétrica de partículas). As variáveis analisadas, teor de sólidos, distribuição de tamanho de partículas, morfologia e composição das partículas entre outros, na massa de lodo bruto e desaguado indicaram diferentes mecanismos de secagem e conseqüente influencia na velocidade de secagem. O uso do fluxo de massa de água evaporada revelou-se adequado para avaliar a fase de secagem. O estudo das micro e macropropriedades do lodo mostram-se decisivos para balisarem pesquisas de desenvolvimento dos sistemas de desaguamento e de reúso dos lodos de ETAs. / The study of involved factors, micro and macroproperties of sludge from water treatment plants (WTP) in dewatering by natural systems with the use of draining beds is the main focus of this research. For this purpose, dewatering assays by draining beds were done with samples from aluminium sulphate and polyaluminium chloride (PA\'CL\') sludge, and monitoring of the climatic variables along the experiments. The results proved the performance of the draining beds in reducing the volume, ranging from 80 to 90% for the sludges from PA\'CL\' and aluminium sulphate and the final rate of solids from 30 to 90%, without consuming the energy. In dewatering phase, independently of the type and volume of the applied sludge, the bigger the flow of dewatering the lesser the value of the applied rate of solids (TAS, Kg/\'M POT.2\', volumetric fraction of particles). The analised variables, solid rates, distribution of the height of the particles, morphology, and composition of the particles among others, in the mass of the brute and dewatered sludge indicated different mechanisms of drying and consequently influence in the rate of drying. The use of the flow of mass of humidity revealed adequate to evaluate the drying phase. The studies of micro and macroproperties of the sludge were decisive to conduct researches of development of dewatering systems and reusing of the sludges from WTP´s.

O estudo dos fatores intervenientes, micro e macropropriedades dos lodos de estação de tratamento de água (ETA), no desaguamento por sistemas naturais, com uso de leito de drenagem, constituiu o principal foco desta pesquisa. Assim, ensaios de desaguamento por leito de drenagem foram realizados com amostras de lodos de sulfato de alumínio e de cloreto de polialumínio (PA\'CL\') e monitoramento das variáveis climáticas. Os resultados comprovaram o desempenho do leito de drenagem para redução de volume, da ordem de 80% e 90% para os lodos de PA\'CL\' e sulfato de alumínio e teor de sólidos final respectivamente de 30 a 90%, sem consumo de energia. Na fase de drenagem, independente do tipo e volume de lodo aplicado, a vazão de drenagem foi maior quanto menor o valor da taxa de aplicação de sólidos - TAS (Kg/\'M POT.2\') (fração volumétrica de partículas). As variáveis analisadas, teor de sólidos, distribuição de tamanho de partículas, morfologia e composição das partículas entre outros, na massa de lodo bruto e desaguado indicaram diferentes mecanismos de secagem e conseqüente influencia na velocidade de secagem. O uso do fluxo de massa de água evaporada revelou-se adequado para avaliar a fase de secagem. O estudo das micro e macropropriedades do lodo mostram-se decisivos para balisarem pesquisas de desenvolvimento dos sistemas de desaguamento e de reúso dos lodos de ETAs. / The study of involved factors, micro and macroproperties of sludge from water treatment plants (WTP) in dewatering by natural systems with the use of draining beds is the main focus of this research. For this purpose, dewatering assays by draining beds were done with samples from aluminium sulphate and polyaluminium chloride (PA\'CL\') sludge, and monitoring of the climatic variables along the experiments. The results proved the performance of the draining beds in reducing the volume, ranging from 80 to 90% for the sludges from PA\'CL\' and aluminium sulphate and the final rate of solids from 30 to 90%, without consuming the energy. In dewatering phase, independently of the type and volume of the applied sludge, the bigger the flow of dewatering the lesser the value of the applied rate of solids (TAS, Kg/\'M POT.2\', volumetric fraction of particles). The analised variables, solid rates, distribution of the height of the particles, morphology, and composition of the particles among others, in the mass of the brute and dewatered sludge indicated different mechanisms of drying and consequently influence in the rate of drying. The use of the flow of mass of humidity revealed adequate to evaluate the drying phase. The studies of micro and macroproperties of the sludge were decisive to conduct researches of development of dewatering systems and reusing of the sludges from WTP´s.

Le contrôle du paludisme ne semble aujourd'hui envisageable que par stratégies combinées ciblant différents stades du parasite. Chez le vecteur, certains mécanismes de la réponse immunitaire pourraient être manipulés pour bloquer le développement sporogonique du parasite. Cette thèse examine les effets de la diversité du vecteur et du parasite dans le couple le plus important en termes d'épidémiologie, A. gambiae - P. falciparum. Des polymorphismes de gènes de l'immunité du moustique contrôlant le niveau d'infection ont été identifiés par étude d'association. Certains d'entre eux ont un effet spécifique selon les isolats de parasites, suggérant de potentielles interactions génotype X génotype. Nous avons déterminé un déséquilibre de liaison très bas dans les populations naturelles de vecteurs, validant notre approche par gènes candidats. Les caractéristiques et les forces évolutives faisant d'A. gambiae un vecteur du paludisme majeur sont discutées. Les diverses populations de vecteurs et parasites peuvent interagir de manière spécifique. Pour tester cela, des infections par des isolats de parasites sympatriques et allopatriques ont été comparées, montrant des intensités plus faibles dans les couples sympatriques. Les profils d'expression des gènes montrent cependant peu de régulations spécifiques aux populations, mais plutôt des différences extrêmes selon les isolats de parasites. Ces résultats suggèrent des effets importants de la diversité entre populations et individus. En conclusion, cette thèse souligne l'importance de la prise en compte de la diversité naturelle des vecteurs et parasites dans les recherches futures sur leurs interactions. / To achieve malaria control a variety of approaches must be combined targeting different stages of the parasites life cycle. With better understanding of mosquito immunity, it is hoped that aspects of natural resistance can be manipulated to prevent parasite development. This thesis investigates the effect of both mosquito and parasite diversity on the mosquitoes response to malaria using the most important human malaria system; Anopheles gambiae-Plasmodium falciparum in natural/semi-natural conditions. Mosquito loci are identified that significantly control infection phenotype, some of which act in a parasite isolate specific manner, highlighting their potential involvement in genotype by genotype interactions. Such research is moving towards genomewide studies; however, on finding very low linkage disequilibrium in wild mosquitoes, it favors candidate gene association studies. A. gambiae characteristics that make it such a good malaria vector are discussed and the evolutionary forces driving these traits. Selection behind vector-parasite interactions can differ spatially and temporally causing specificities in sympatric couples. Sympatric and allopatric mosquito infections with malaria are compared, showing that sympatric infections develop lower infection intensities suggesting local adaptation. Mosquito gene expression profiles highlight a small number of genes differentially regulated between sympatric and allopatric infections, however extreme differences in gene regulation are observed within populations, probably driven by the variable nature of malaria parasites. This thesis highlights the importance of taking into account natural diversity in future research.

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