O presente trabalho reúne elementos teóricos e experimentais envolvendo os principais fenômenos hidráulicos causadores de danos em bombas hidráulicas de fluxo radial de grande porte. A preocupação do texto está centrada em proporcionar um aprofundamento técnico acerca destes fenômenos hidráulicos de cavitação, a fim de contribuir na análise e solução de problemas em sistemas de bombeamento. Além disso, este trabalho tem a pretensão de transmitir alguma experiência prática fornecida por um evento em que foi detectada a ocorrência de dois destes fenômenos hidráulicos simultâneos em um sistema de bombeamento e a partir disso, realizou-se a análise completa deste evento, incluindo as propostas de solução aos problemas encontrados, as análises técnica e econômica das alternativas de solução e a análise após a implantação da proposta escolhida. O texto apresenta também uma grande quantidade de gráficos e figuras que buscam facilitar a compreensão das definições e das análises dos fenômenos hidráulicos, além de exemplificar os danos típicos dos fenômenos pela visualização direta destes danos nas bombas. / This work presents theoretical and experimental data on the principal hydraulic phenomena responsible for damage in high loaded radial flow hydraulic pumps. The main objective is to provide a technical overview in order to contribute for the analysis and solution on these cavitation pumping systems problems. In addition this work intends to transmit practical experience through a “study of case" where two simultaneous of these hydraulic phenomena were detected. The complete analysis of technical and economical aspects of the alternatives solutions is presented including a great amount of graphs and illustrations that better explain the phenomena of cavitation in hydraulic pumps.

O presente trabalho teve como objetivo avaliar a influência da velocidade ascensional de recirculação e da estratégia de alimentação na eficiência de um reator anaeróbio com biomassa imobilizada operado em bateladas seqüenciais tratando efluentes provenientes de um laticínio de pequeno porte. Avaliaram-se três condições operacionais com valores de velocidade de 0,2 m.h-1, 3,8 m.h-1 e 6,4 m.h-1, com tempo de ciclo de 48 horas. Finda esta etapa, avaliou-se a influência do volume tratado na eficiência do sistema. Nesta avaliação, o tempo de ciclo foi de 24 horas e estudaram-se duas condições experimentais, nas quais diariamente o reator era alimentado com 50% e 67% de seu volume. O reator, com volume total de 1000 L, foi instalado em área próxima ao laticínio. O suporte (\"biobob\") utilizado para imobilização da biomassa foi um enchimento plástico preenchido com espuma de poliuretano. A alimentação foi feita com efluentes oriundos do laticínio escola da Prefeitura do Campus USP Pirassununga - PUSP-P com carga orgânica variável, de acordo com suas atividades. O monitoramento do reator foi realizado através de análises de demanda química de oxigênio (DQO) em amostras filtradas em membrana de poro 1,2 µm e brutas, nitrogênio total Kjedahl e amoniacal, alcalinidade a bicarbonat o e ácidos voláteis totais. Verificada a estabilidade do sistema, realizaram-se amostragens temporais para medida de concentração de substratos e metabólitos intermediários. A biomassa oriunda do inóculo e do reator nas três primeiras condições experimentais foi analisada através de exames de microscopia de contraste de luz e fluorescência, análises de biologia molecular e atividade metanogênica específica. O período total de monitoramento no estudo da influência da velocidade ascensional de recirculação fo i de 570 dias. As eficiências médias de remoção de matéria orgânica em amostras brutas foram 82 ± 11 %; 84 ± 9%; 87 ± 9 %, quando as velocidades foram de 0,2 m.h-1, 3,8 m.h-1 e 6,4 m.h-1, respectivamente. As eficiências médias de remoção de matéria orgânica em amostras filtradas foram 82 ± 9%; 83 ± 13 %; 87 ± 9 %, quando as velocidades foram de 0,2 m.h-1, 3,8 m.h-1 e 6,4 m.h-1, respectivamente. Não foram verificadas diferenças significativas entre as eficiências de remoção de matéria orgânica à medida que a velocidade ascensional aumentou, todavia percebeu-se diminuição no desvio padrão de tal parâmetro, favorecimento no processo de geração e consumo de ácidos e aumento na velocidade de conversão da matéria orgânica. Os resultados das análises de biologia molecular demonstraram que a biomassa se modificou adaptando-se ao efluente, mas apresentando pouca variação entre as duas últimas condições operacionais. Quando o tempo de ciclo foi diminuído para 24 horas, e o sistema alimentado com 50% e 67% de seu volum e reacional, também não se verificou diferenças significativas em relação à eficiência de remoção de matéria orgânica, todavia a última condição operacional a que proporcionou maior volume de efluente tratado por dia. Conclui-se que o ASBBR foi eficiente, robusto e confiável para o tratamento de efluentes de laticínios nas condições de operações testadas. / The aim of the present study was to evaluate the influence of the recirculation rate and feed strategy on the efficiency of an Anaerobic Sequencing Batch Biofilm Reactor - ASBBR -treating effluents from a small dairy industry. Three operational conditions were studied in which the recirculation rate was 0.2 m.h-1, 3.8 m.h-1 e 6.4 m.h-1 and the cycle time was 48 h. When this assay was finished, the cycle time was decreased to 24 hours and two operational conditions were studied, in which the reactor was fed with 50% and 67% of its reaction volume, respectively. The reactor with total volume of 1000L was assembled in an area closed to the dairy. The biomass was immobilized in plastic supports containing polyurethane foam. The reactor was fed by effluents from the dairy school ( Prefeitura do Campus USP Pirassununga - PUSP-P) with organic loading rate variable according to the operations occurred in the plant. The system was monitored through chemical oxygen demand (COD) analyses, and measurements of nitrogen, alkalinity and volatile acids concentrations. When stability was verified, temporal profiles of substrate and metabolites concentrations were obtained. The biomass from the inoculum and from the reactor (operational conditions 1, 2 and 3) was analyzed through microscopic exams, molecular biology analyses and specific methanogenic activity assays. The monitoring period for the study of the influence of the recirculation rate lasted 570 days. The average efficiencies of organic matter removal were 82 ± 11 %; 84 ± 9%; 87 ± 9 %, when the velocities were 0.2 m.h-1, 3.8 m.h-1 e 6.4 m.h-1, respectively. The average efficiencies of organic matter removal in filtrated samples were 82 ± 9%; 83 ± 13 %; 87 ± 9 % when the velocities were 0.2 m.h-1, 3.8 m.h-1 e 6.4 m.h-1, respectively. Statistic differences were not verified; nevertheless it was possible to observe that the values of standard errors decreased, the production and consumption of the volatile acids improved and the rate of organic matter removal increased when the velocity was rose. The results from the molecular biology analyses showed that the biomass changed and adapted to the treatment conditions, presenting low variation along the last condition. When the cycle time was decreased to 24 hours, and the system was fed with 50% and 67%, statistic difference among the efficiencies were again not observed, nevertheless, the latter condition resulted in the highest daily treated volume. It was possible to conclude that the ASBBR was efficient, robust and reliable in treating dairy effluents at the practiced conditions.

Les lymphocytes T régulateurs CD4+ Foxp3+ (Treg) sont des acteurs clés de l’homéostasie du système immunitaire. Grâce à des fonctions immunosuppressives, les Treg contrôlent la survenue et l’amplitude des réponses immunitaires. Ils sont ainsi essentiels à la prévention de pathologies auto-immunes et inflammatoires chroniques. Comme les autres lymphocytes Tαβ (Tconv), les Treg se différencient dans le thymus à partir d’un même précurseur hématopoïétique. Bien qu’encore méconnu, le développement des Treg diffère de celui des Tconv par la nature des interactions ou des signaux échangés entre les précurseurs et les cellules stromales thymiques. Dans notre équipe nous nous intéressons à la génération intra-thymique des Treg, et particulièrement aux facteurs pouvant influencer ce processus. Ainsi, au fait de l’involution du thymus avec l’âge et de la réduction de la production de Tconv qui en découle, nous avons monitoré spécifiquement le développement des Treg au cours de la vie. De façon surprenante, nous avons observé une diminution plus importante de la production de Treg, que de Tconv, avec l’âge. Cependant, nous avons constaté que la population de Treg thymique n’était pas seulement constituée de cellules en développement, mais également de cellules plus matures, présentant un phénotype activé et différencié, dont la proportion s’accroit avec l’âge. Nous avons alors démontré qu’il s’agissait de Treg ayant recirculé depuis la périphérie (tissus, organes lymphoïdes) vers leur organe d’origine ; et que ces derniers étaient capables de supprimer spécifiquement le développement de leurs précurseurs en rentrant en compétition pour un facteur de survie essentiel : l’interleukine 2 (IL-2). Ainsi, nos travaux ont révélé l’existence d’une boucle de rétrocontrôle négatif du développement thymique des Treg. Cette découverte nous a alors amené à reconsidérer les données de la littérature qui décrivaient un nombre plus élevé de Treg thymiques chez des souris NOD, enclines aux auto-immunités, par rapport aux souris B6 résistantes. Nous voulions déterminer si la variation du nombre de Treg thymiques d’une souche à l’autre résultait d’une réelle influence génétique sur le développement des Treg, ou bien sur la recirculation de ces derniers. L’analyse comparative de la proportion de Treg recirculants a révélé que celle-ci était toujours plus élevée chez les souris NOD par rapport aux souris B6 dès les premières semaines de vie. Par ailleurs, nous avons démontré que cette forte densité de Treg recirculants chez les souris NOD résultait d’une hyper-activation des Treg dans la périphérie, connue pour favoriser la migration de ces derniers vers le thymus. Enfin, en accord avec le mécanisme de rétrocontrôle précédemment décrit, la plus forte présence de Treg recirculants chez la souris NOD entraine une inhibition plus précoce du développement thymique des Treg. En conclusion, l’ensemble de nos données rapportent l’existence de variations inter-individuelles du développement des lymphocytes T régulateurs dans le thymus. Ces variations conditionnées par l’âge et/ou par la génétique de l’individu sont exercées en partie sur le processus de recirculation des Treg périphériques vers le thymus, ce qui entraine l’inhibition du développement de nouveaux Treg. Les conséquences sur l’organisme de ces variations quantitatives du développement des Treg devront être déterminées, et s’inscriront dans une démarche globale visant à une meilleure prédiction de la susceptibilité des individus vis-à-vis des immuno-pathologies. / CD4+ Foxp3+ regulatory T lymphocytes (Treg) are key players in the immune homeostasis. Thanks to their suppressive functions, Treg control the occurrence and the intensity of immune responses. They are thus essential in preventing the onset of auto-immune and chronic inflammatory diseases. Like other αβ T lymphocytes (Tconv), Treg differentiate in the thymus from a common hematopoietic precursor. Although still not completely unveiled, Treg development seems to differ from that of Tconv due to the interactions and signals exchanged between Treg precursors and thymic stromal cells. The research of our team focuses on the intra-thymic generation of Treg, and on factors that could influence this process. With age, the size of the thymus decreases and as a consequence the thymic production of new Tconv cells is reduced. Then while studying the differential requirements for Tconv and Treg cell development, we monitored their thymic production throughout life. Surprisingly, we observed a stronger decrease in Treg than Tconv production with age. However, we also found that the thymic Treg population was not only constituted by newly developing cells, but also by mature cells whose proportion increased with age, and exhibited an activated and differentiated phenotype. We then demonstrated that this population comprised Treg that have recirculated from the periphery (tissues, lymphoid organs) to the thymus. Mature thymic Treg were able to specifically suppress the development of their precursors by limiting the availability of an essential survival factor: the interleukin-2 (IL-2). Our work therefore demonstrated the existence of a negative feedback loop exerted by peripheral Treg controlling thymic Treg development. This finding led us to reconsider the data from the literature which described a higher number of thymic Treg in NOD mice, prone to autoimmunity, compared to resistant B6 mice. We determined whether the variation in the number of thymic Treg from one strain to another resulted from a genetic control on thymic Treg development, or on Treg recirculation. Strikingly, a greater proportion of recirculating thymic Treg was observed in NOD than in B6 mice at all the ages analyzed. We have subsequently demonstrated that this high amount of recirculating Treg in NOD mice was due to hyper-activation of peripheral Treg, favoring their migration to the thymus. Finally, in agreement with the negative feedback loop we previously described, the higher density of recirculating Treg in the thymus of NOD mice induced an earlier inhibition of the intra-thymic development of new Treg. To conclude, we report here the existence of inter-individual variations of regulatory T lymphocytes development in the thymus. These age-dependent and/or genetic-dependent factors seem to shape Treg recirculation from the periphery to the thymus, and as a consequence the de novo development of Treg. It will be important, in the future, to determine the impact on the organism of these quantitative variations in Treg development and on the susceptibility towards immuno-pathologies

La combustion sans flamme est un mode de combustion innovant dans le domaine des économies d'énergie et de la réduction des émissions polluantes, qui reste toutefois encore peu étudié. L'objectif de cette étude est de caractériser ces mécanismes par une étude expérimentale. La première étape de cette étude a été réalisée sur une installation d'essais semi-industrielle. Différents moyens de mesure dans la flamme ont été utilisés pour caractériser le mode d'accrochage de la flamme, la structure des zones de réactives, les recirculations des produits de combustion et leur impact sur la combustion et les émissions polluantes. Parallèlement, une installation d'essais de laboratoire à été mise en place. La caractéristique essentielle de cette installation est la possibilité de changer une des dimensions de la chambre tout en gardant identiques les conditions opératoires. Différents paramètres (puissance, température de l'air, température des parois, taux d'aération, confinement de la flamme) sont modifiés afin de caractériser leur impact sur le régime de combustion sans flamme. <br />Les résultats montrent que la flamme peut être divisée en deux zones. Alors que la réaction principale se situe où le jet d'air et de gaz naturel se rejoignent, une première zone réactive est aussi observée dans la zone de recirculation interne, assurant la stabilisation de la flamme. La recirculation des produits de combustion est mise en évidence et quantifiée à partir des résultats des mesures dans la flamme. Entraînées par l'écoulement principal, ces recirculations induisent une importante dilution dans les zones réactives, où la concentration en CO et la température restent à de faibles niveaux. Les oxydes d'azote sont principalement produits par voie thermique, mais restent très faibles. Par ailleurs, un mécanisme de réduction dans la flamme des oxyde d'azote présents dans les recirculations peut être observé. L'étude paramétrique montre que si la puissance n'a pas d'influence sur le régime de combustion, la combustion sans flamme est possible avec de l'air non préchauffé. Par ailleurs, une augmentation du taux d'aération réduit la dilution de la zone réactive par les inertes. Pour de fortes augmentations du taux d'aération, on peut observer l'apparition d'une troisième zone de réaction à l'extérieur des jets de gaz naturel ; on quitte alors le régime de combustion sans flamme

This thesis deals with turbulent mixing processes occurring in internal combustion engines, when applying exhaust gas recirculation (EGR). EGR is a very efficient way to reduce emissions of nitrogen oxides (NOx) in internal combustion engines. Exhaust gases are recirculated and mixed with the fresh intake air, reducing the oxygen con- centration of the combustion gas and thus the peak combustion temperatures. This temperature decrease results in a reduction of NOx emissions. When applying EGR, one is often faced with non-uniform distribution of exhaust among and inside the cylinders, deteriorating the emission performance. The mixing of exhaust gases and air is governed by the flow in the engine intake manifold, which is characterized by unsteadiness due to turbulence and engine pulsations. Moreover, the density cannot be assumed to be constant due to the presence of large temperature variations.Different flow cases having these characteristics are computed by compressible Large Eddy Simulations (LES). First, the stationary flows in two T-junction type geometries are investigated. The method is validated by comparison with experimental data and the accuracy of the simulations is confirmed by grid sensitivity studies. The flow structures and the unsteady flow modes are described for a range of mass flow ratios between the main and the branch inlet. A comparison to RANS computations showed qualitatively different flow fields.Thereafter, pulsating inflow conditions are prescribed on the branch inlet in or- der to mimic the large pulsations occurring in the EGR loop. The flow modes are investigated using Dynamical Mode Decomposition (DMD).After having established the simulation tool, the flow in a six-cylinder engine is simulated. The flow is studied by Proper Orthogonal Decomposition (POD) and DMD. The mixing quality is studied in terms of cylinder-to-cylinder non-uniformity and temporal and spatial variances. It was found that cycle-averaging of the concentration may give misleading results. A sensitivity study with respect to changes in the boundary conditions showed that the EGR pulsations, have large influence on the results. This could also be shown by POD of the concentration field showing the significance of the pulses for the maldistribution of exhaust gases.Finally, the flow in an intake manifold of a four-cylinder engine is investigated in terms of EGR distribution. For this geometry, pipe bends upstream of the EGR inlet were found to be responsible for the maldistribution. / <p>QC 20130207</p>

The effects of unilateral eyestalk ablation, diets and sex ratios were evaluated on two wild populations of Farfantepenaeus aztecus in a closed recirculating maturation system. Ovarian development and spawning frequencies of ablated females in both studies were higher than the non-ablated females. Replacement of bloodworms in maturation diet with enriched adult Artemia sp. had no negative effect on the number of eggs spawned and resulted in increased hatch and survival rates from Nauplius I to Zoea I. Life span of ablated females fed enriched Artemia sp. was longer than ablated females fed bloodworms. Replacement of the expensive bloodworm diet component with adult enriched Artemia sp. is possible without negative impact on female reproductive performance. Reducing male to female ratio from 2:1 to 1:1 resulted in a 1.25% decrease in spawning activities of ablated females. The life cycle of pond-raised F1 generation F. aztecus also was completed in the closed recirculating system using unilateral eyestalk ablation as previously described. This study found diets that contained an enriched adult Artemia sp. component performed superior (i.e. hatch rate, nauplii and zoea production) to a diet containing bloodworms. Six consecutive larval rearing trials evaluated changes in select water quality indicators and their effect on growth, survival, and stress tolerance of F. aztecus postlarvae cultured in artificial seawater under closed recirculating and flow-through conditions. The closed recirculating larval rearing system successfully produced five-day-old postlarvae (PL) from Zoea I (Z1) with similar dry weights, lengths and stress resistance to PL produced under standard water exchange practices. The trickling biofilters were found to be a limiting component of this system. A submerged coral biofilter was added to the system and effectively processed culture water for re-use. Addition of the submerged biofilter resulted in improved survival rates in Trials 4, 5 and 6. These studies demonstrate maturation and larval rearing of F. aztecus is feasible in closed recirculating systems. Implementation of these systems in hatcheries bolsters biosecurity while reducing the environmental impact of hatchery effluent. Recirculating and re-use systems are therefore essential in the further development of sustainable hatchery programs for endemic species.

This study was concerned with the performance of biofuels in diesel engines. Generally, the basic combustion and emission characteristics of Rapeseed Oil (RSO) and Soya Oil (SO) result in a lower in-cylinder pressure peak than diesel. This led to the reduction of Nitrogen Oxides (NOx) emissions and to relatively high soot emissions. Further measurements of RSO were done in order to investigate the influence of injection pressure, injection timing and Exhaust Gas Recirculation (EGR) on combustion and emission characteristics. A high soot emission from RSO was reduced by increased injection pressure. Moreover, injection timing also had to be varied in order to reduce the soot emissions from RSO. The retarded injection timing (3 deg bTDC) and increased injection pressure (1200 bar) for the blend of 30% RSO resulted in a reduction of soot emission to the same level as from diesel fuel. Further investigation regarding the soot emissions was done for Rapeseed Methyl Ester (RME) under turbocharged engine operation. The application of the boost pressure resulted in stable engine operation at a late injection timing of 5 deg aTDC. A simultaneous reduction of soot and NOx emissions has been achieved for RME at an injection timing of TDC and high EGR percentage (40 – 50 %). The soot particles size distribution under different engine operating conditions for RME and diesel has also been investigated. Moreover, the characteristic of Electrostatic Mobility Spectrometer (EMS) and the design of primary dilution system have been provided in order to understand the influence of the dilution process and to obtain more real results. Generally, RME showed less particles concentration in the nucleation mode when compared to diesel. Moreover, high EGR caused a shift of the particles from the nucleation mode by agglomeration into the accumulation mode for both fuels. The effect of injection pressure could only be seen in the accumulation mode, where high injection pressure slightly reduced the concentration number. The soot emission was effectively reduced by the usage of the diesel particulate filter (DPF). For this purpose, the soot particles size distributions before and after the DPF have been measured at different engine speeds and loads. At low engine torque, the soot was effectively filtered while the operation under high engine loads resulted in low soot particle concentration especially in the nucleation mode, after the DPF.

With an increased urgency for global action towards climate change mitigation, this research was undertaken with the aim of evaluating post-combustion CO2 capture as an emission abatement strategy for gas-fired power plants. A dynamic rate-based model of a capture plant with MEA solvent was built, with imposed chemical equilibrium, and validated at pilot scale under transient conditions. The model predicted plant behaviour under multiple process inputs and disturbances. The validated model was next used to analyse the process and it was found that CO2 absorption is mass transfer limited. The model was then improved by explicitly adding reactions rate in the model continuity, the first such dynamic model to be reported for the capture process. The model is again validated and is observed to provide better predictions than the previous model. Next, high fidelity models of a gas-fired power plant, a scaled-up capture plant and a compression train were built and integrated for 90% CO2 capture. Steam for solvent regeneration is extracted from the power plant IP/LP crossover pipe. Net efficiency drops from 59% to 49%, with increased cooling water demand. A 40% exhaust gas recirculation resulted in a recovery of 1% efficiency, proving that enhanced mass transfer in the capture plant reduces solvent regeneration energy demands. Economic analysis reveals that overnight cost increases by 58% with CO2 capture, and cost of electricity by 30%. While this discourages deployment of capture technology, natural gas prices remain the largest driver for cost of electricity. Other integration approaches – using a dedicated boiler and steam extraction from the LP steam drum – were explored for operational flexibility, and their net efficiencies were found to be 40 and 45% respectively. Supplementary firing of exhaust gas may be a viable option for retrofit, as it is shown to minimise integrated plant output losses at a net efficiency of 43.5%. Areas identified for further study are solvent substitution, integrated plant part load operation, flexible control and use of rotating packed beds for CO2 capture.

COELHO, Anderson Alan da Cruz. Cultivo integrado de juvenis de Tilápia do Nilo (Oreochromis niloticus) com a microalga Spirulina platensis: uma alternativa para tratamento de efluente aquícola. 2012. 43 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Engenharia de Pesca, Fortaleza-CE, 2012 / Submitted by Nádja Goes (nmoraissoares@gmail.com) on 2016-07-11T11:33:51Z No. of bitstreams: 1 2012_dis_aaccoelho.pdf: 607546 bytes, checksum: 12fe04486dfe8ee87995d9e313b1cb2c (MD5) / Approved for entry into archive by Nádja Goes (nmoraissoares@gmail.com) on 2016-07-11T11:46:06Z (GMT) No. of bitstreams: 1 2012_dis_aaccoelho.pdf: 607546 bytes, checksum: 12fe04486dfe8ee87995d9e313b1cb2c (MD5) / Made available in DSpace on 2016-07-11T11:46:06Z (GMT). No. of bitstreams: 1 2012_dis_aaccoelho.pdf: 607546 bytes, checksum: 12fe04486dfe8ee87995d9e313b1cb2c (MD5) Previous issue date: 2012 / The environmental potential impacts from intensive aquaculture have increased public concern about the sustainability of the activity itself. The present work aimed to evaluate the zootécincos parameters of Nile tilapia , water quality, algal biomass production and rate of nitrogen removal compounds by Spirulina platensis realize an integrated cultivation of Nile tilapia (Oreocrhomis niloticus) with Spirulina platensis in a closed system of water circulation. The experiment took place at the Biotechnology Aquaculture Applied Center (CEBIAQUA) of The Fishing Engineering Department of the Federal University of Ceará. Tilapias culture was conducted in three treatments with four replicates at densities of 010, 0,15 and 0,20 juveniles L-1. The tilapias were fed ad libitum with a commercial ration (0,8 mm) containing 55% crude protein (CP), administered daily at 9, 13 and 17 h. For Spirulina platensis culture, initially, the inoculum was cultivated in an alternative chemical medium and later adapted to the Nile tilapia effluent and inoculated into 12 polyethylene basins. Throughout the experiment, the water of fishes boxes and of the respective microalgae basins was reused in the closed recirculation system between the two cultures, with only replacement of water due to evaporation. After the full development of S. platensis in the basins, the microalgae was collected using a 60 µm screen. The pH, temperature, dissolved oxygen, and levels of N-ammonia, N-nitrate and N-nitrite were also monitored during all the experimental period. The results showed that the most efficient stocking density was 0,10 L-1, because despite having the same final biomass of the other treatments it presented the lowest feed conversion ratio. The microalgae S. platensis was easily adapted and developed very well in the Nile tilapia’s effluent, regardless of fishes stocking density. With respect to water quality, it was evident that the cultures integration maintained the levels of N-ammonia (0,26 ± 0,03 mg L-1), N-nitrates (2,55 ± 0,71 mg L-1) and N- nitrites (0,19 ± 0,01 mg L-1) within acceptable values for the Nile tilapia culture. / Os potenciais impactos ambientais provenientes da aquicultura intensiva têm aumentado a preocupação da sociedade quanto à sustentabilidade da própria atividade. Com o presente trabalho teve como objetivo avaliar, os parâmetros zootécincos das tilápias do Nilo, qualidade de água, produção de biomassa algal e taxa de remoção dos compostos nitrogenados pela microalga Spirulina platensis em um cultivo integrado da tilápia do Nilo (Oreocrhomis niloticus) com a microalga S. platensis em um sistema fechado de circulação de água. O experimento foi realizado no Centro de Biotecnologia Aplicada a Aquicultura (CEBIAQUA) do Departamento de Engenharia de Pesca da Universidade Federal do Ceará. O cultivo das tilápias foi inteiramente casualizado e realizado em três tratamentos com quatro repetições nas densidades de 0,1; 0,15 e 0,20 juvenis L-1. As tilápias foram alimentadas ad libitum com ração comercial (0.8 mm), contendo 55% de proteína bruta (PB), fornecida às 9, 13 e 17 h, sete dias por semana. Para o cultivo de Spirulina platensis, inicialmente, o inóculo foi cultivado em meio químico alternativo e posteriormente adaptado ao efluente de tilápia do Nilo e inoculado em 12 bacias de polietileno. Durante todo o experimento, a água das caixas dos peixes e das respectivas bacias das microalgas foi reutilizada no sistema de recirculação fechado entre as duas culturas, havendo apenas reposição de água por conta da evaporação. Após o completo desenvolvimento da S. platensis nas bacias, a coleta da microoalga foi realizada através de filtragem da água em telas de 60 µm. Foram ainda monitorados o pH, temperatura, oxigênio dissolvido, bem como determinados os níveis de N-amônia, N-nitrato e N-nitrito durante o período experimental. Os resultados mostraram que a densidade de estocagem mais eficiente para o cultivo das tilápias foi 0,10 juvenis L-1, pois apesar de ter resultado na mesma biomassa final dos demais tratamentos, foi a que apresentou a menor taxa de conversão alimentar. A microalga S. platensis se adaptou facilmente e se desenvolveu muito bem no efluente das tilápias do Nilo, independente da densidade de estocagem dos peixes. Com relação à qualidade de água, foi evidenciado que a integração das culturas manteve os níveis de N-amônia (0,26 ± 0,03 mg L-1), N-nitrato (2,55 ± 0,71) e N-nitrito (0,19 ± 0,01) dentro dos valores aceitáveis para o cultivo da tilápia do Nilo.

CAVALCANTE JÚNIOR, Valdemar. Reuso de água em um sistema integrado com peixes, sedimentação, ostras e macroalgas. 2006. 56 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Engenharia de Pesca, Fortaleza-CE, 2006 / Submitted by Nádja Goes (nmoraissoares@gmail.com) on 2016-07-22T13:35:05Z No. of bitstreams: 1 2006_dis_vcavalcantejúnior.pdf: 798516 bytes, checksum: e6e72e0be76d7e9e806c45e94f8677e1 (MD5) / Approved for entry into archive by Nádja Goes (nmoraissoares@gmail.com) on 2016-07-22T13:35:22Z (GMT) No. of bitstreams: 1 2006_dis_vcavalcantejúnior.pdf: 798516 bytes, checksum: e6e72e0be76d7e9e806c45e94f8677e1 (MD5) / Made available in DSpace on 2016-07-22T13:35:22Z (GMT). No. of bitstreams: 1 2006_dis_vcavalcantejúnior.pdf: 798516 bytes, checksum: e6e72e0be76d7e9e806c45e94f8677e1 (MD5) Previous issue date: 2006 / Intensive culture effluents have high levels of dissolved nutrients mainly ammonia and others suspended solids. The objective of this work was to use integrated aquaculture with fishes, sedimentation, oysters and macroalgae to improve water quality from a salt water tilapia culture. The fishes water was distributed in three sedimentation aquariums to a 24 h period. Then, water was removed to three oysters aquariums to a equal 24 h period. Later, oysters water was removed to three macroalgae aquariums to more 24 h. Finally, macroalgae water returned to the fishes aquariums. Water turbidity and ammonia, nitrates, nitrites and phosphates concentrations were determined daily. The system was efficient to significantly reduce turbidity and ammonia and phosphates water levels. Nitrates and nitrites levels only were reduced during the sedimentation after system stabilization / Os efluentes de cultivo intensivo contêm elevadas concentrações de nutrientes dissolvidos, principalmente amônia, além de outros sólidos em suspensão. O objetivo desse trabalho foi utilizar a aqüicultura integrada com sedimentação, ostras e macroalgas para melhorar a qualidade da água proveniente de um cultivo de tilápias em água salgada. A água dos peixes foi distribuída em três aquários para sedimentação por 24 horas. Em seguida, a água foi transferida para três aquários com ostras, por igual período de 24 horas. Posteriormente, a água das ostras foi transferida para três aquários com macroalgas por mais 24 horas. Finalmente, a água das macroalgas retornou para os aquários com os peixes. Diariamente, foram avaliados a turbidez da água e as concentrações de amônia, nitratos, nitritos e fosfatos. O sistema foi eficiente em reduzir significativamente a turbidez e os níveis de amônia e fosfatos da água. Os níveis de nitratos e nitritos só foram reduzidos na sedimentação, após a estabilização do sistema. i