Zugl.: Karlsruhe, Univ., Diss., 2008 / Hergestellt on demand

Η παρούσα εργασία είναι χωρισμένη σε τέσσερις θεματικές ενότητες. Στην πρώτη ενότητα παρουσιάζονται οι βασικές φυσικοχημικές μέθοδοι επεξεργασίας που χρησιμοποιήθηκαν, οι οποίες είναι η κροκίδωση/καθίζηση και η διήθηση με μεμβράνες, καθώς και οι βασικές αρχές που τις διέπουν. Η δεύτερη ενότητα της παρούσας εργασίας αποτελείται από την παρουσίαση εφαρμογών της τεχνολογίας μεμβρανών σε συνδυασμό με απόσταξη υπό κενό και διάφορα προσροφητικά μέσα για την αντιμετώπιση προβλημάτων της οινοποιίας. Πιο συγκεκριμένα, εξετάστηκε η αφαίρεση πτητικής οξύτητας από ερυθρό και λευκό οίνο, που οδήγησε σε συνολική απομάκρυνση της τάξεως του 90%, καθιστώντας τον οξειδωμένο οίνο κατάλληλο προς πώληση. Επίσης εξετάστηκε η απομόνωση αιθανόλης και ταυτόχρονη παραγωγή οίνου με μειωμένο περιεχόμενο σε αλκοόλ. Με την προτεινόμενη μέθοδο παρήχθει διάλυμα αιθανόλης 23% vol και οίνος με μειωμένο αλκοόλ 6.7% vol. Τρίτη και τελευταία εφαρμογή ήταν η αφαίρεση αναγωγικών οσμών από λευκό οίνο, η οποία επιτεύχθηκε πλήρως με τη χρήση φίλτρου ενεργού άνθρακα. Στην τρίτη ενότητα παρουσιάζεται μια διεργασία επεξεργασίας αποβλήτου βιομηχανίας χρωμάτων με το συνδυασμό ενός βήματος κροκίδωσης/καθίζησης με μεμβράνες υπερδιήθησης και αντίστροφης ώσμωσης. Το τελικό διήθημα της διεργασίας, από περίπου 20000 mg/l COD που είχε το αρχικό απόβλητο, έχει περίπου 50 mg/l COD, γεγονός που το καθιστά κατάλληλο για ανακύκλωση στη βιομηχανία, ή απόρριψη στο περιβάλλον. Στην τέταρτη και τελευταία ενότητα παρουσιάζεται μια συγκριτική ανάλυση και ανάλυση βιωσιμότητας των διαθέσιμων μεθόδων επεξεργασίας αποβλήτου ελαιοτριβείου, βασισμένες στην αποδοτικότητα, το κόστος και το ενεργειακό αποτύπωμα της κάθε μεθόδου. Τέλος παρουσιάζεται μια μέθοδος επιλογής της καταλληλότερης μεθόδου επεξεργασίας σύμφωνα με τη βαρύτητα που δίνει κάποιος σε κάθε ένα από τα τρία προαναφερθέντα χαρακτηριστικά. / The present study is divided into four chapters. In the first chapter the psychochemical treatment methods that were used with the underlying basic principles are presented. These methods include coagulation/flocculation and membrane filtration. The second chapter is concerned with the implementation of membrane filtration, combined with vacuum evaporation and adsorption materials, in order to address problems occurring in winery processes. More specifically, the removal of volatile acidity from red and white wine was tested, leading to its reduction by 90%, rendering oxidized wine suitable for distribution. Furthermore, the removal of ethanol and the production of low alcohol wine were tested. Through the proposed method, a solution with 23% vol of ethanol and wine with 6.7 vol % were produced. Third and last application was the removal of odors from white wine, which was accomplished through the use of activated carbon. In the third chapter a process for the treatment of paint industry effluents with the combination of coagulation/flocculation with Ultrafiltration and Reverse Osmosis membranes is presented. The final effluent, compared to the initial COD which was around 20000 mg/l, had a 50 mg/l COD and was suitable for recycling in the industrial process or to be rejected to the environment. In the fourth and final chapter a sustainability analysis and benchmarking of the existing treatment methods of Olive Mill Wastewater is presented, based on their effectiveness, cost and CO2 emissions. Finally, a selection technique for the most suitable method is presented, based on the weight given to each one of the aspects given above, by the user.

A comparison of fouling in osmotically driven processes with that in pressure driven processes is the main focus of the thesis. Forward osmosis (FO) and reverse osmosis (RO) have received considerable attention for water treatment and seawater desalination. This research compared the nature of fouling in FO mode with that in RO starting with the same initial flux in connection with cleaning effects and then comparing to those in ultrafiltration membranes. In all cases, with cleaning as an integral part, the extent of fouling reversibility, and the question whether a critical flux could be determined were examined. The work during the first phase (undertaken at Oxford) quantified the removal of reversible fouling through rinsing by cold and hot water for a range of concentrations using the foulants dextran and carboxymethyl cellulose. The flux-TMP relationship was conventionally compared to that of the clean water flux. The later phase (at Singapore) compared the fouling in FO and RO by alginate in terms of multiple parameters using cellulose tri acetate (CTA) and thin film composite (TFC) membranes. Silica and alginate were selected as model foulants. Whilst experimental water flux profiles in the present study did not exhibit significant differences in trend between FO and RO fouling, foulant resistance for FO was found to be increasingly greater than for RO with the progression of the fouling tests. This was further corroborated by membrane autopsies post fouling tests; both foulant mass deposition density and specific foulant resistance for FO were greater than for RO. The analysis clearly revealed that FO is essentially more prone to fouling than RO which was presumably due to less flux decline in FO (or greater average flux) as compared to that in RO in result of ICP-self compensation effect which is opposite to the prevailing claim in the literature. Additionally, the present study did not find evidence that hydraulic pressure in RO has a role in foulant layer compaction. FO membrane fouling by real waters was the focus of the final phase of the research at SMTC. Pilot scale FO experiments were conducted on spiral wound CTA membrane with treated waste water obtained from a NEWater factory (Singapore) as the feed. In the second stage, experiments were repeated at bench scale with membrane coupons taken from the spiral wound membranes used earlier. The key finding was that the mass transfer coefficients in the Spiral-Wound module were around 50% lower than the corresponding values in the flat sheet unit and this severely limited the fluxes. The reason could be attributed to strong internal concentration polarisation in the former, where tightly wound spacers act to increase the structural parameter.

The work is focused on the status and role of zebra mussels (Dreissena polymorpha) in the water reservoir Želivka. Literature review summarizes the basic characteristics of living zebra mussels and its impact on the aquatic ecosystem. Current knowledge about this invasive bivalves show that its presence in the water reservoir has certain advantages, but also disadvantages. The main advantage is that zebra as filtrator, increases the transparency of the water and provides food for the animals living in the aquatic environment, or in its vicinity. Disadvantages are then mainly from the economic point of view, the zebra clogs pipes and thus prevents water flow and attached to marker buoys, fishing nets and attaches to the hulls of ships that can be attacked from the inside. In field part population of zebra mussels was sampled in different parts of the reservoir and identified following parameters (temperature and oxygen stratification, coverage to substrate coverage depending on the depth and the substrate, the length of shells according to the horizontal and vertical gradient filtering capacity and the volume rate). The results showed that the incidence and size of shells affects both horizontal and vertical gradient. Zebra mussels occur most depth 1-9 m on rocky, or stony substrate. The greatest incidence was found at Budeč and at Hráz, where the water is less eutrophic than the Zahrádka. Based on these parameters, and literature data was calculated hypothetical filter capacity and discussed its possible impact on the ecosystem components of the reservoir.

L'objectif de cette thèse est de progresser dans la compréhension du colmatage lors de la filtration de la matière molle (particules colloïdales et bactéries) et d'étudier l'efficacité et la faisabilité de séparateurs microfluidiques. Ces recherches sont réalisées avec des puces microfluidiques constituées de canaux dont la taille est du même ordre de grandeur que les objets filtrés. Ces puces, conçues pour représenter les processus ayant lieu en microfiltration frontale et tangentielles, permettent d'observer in-situ sous microscope les mécanismes de colmatage. Le système est instrumenté avec des capteurs de débit et de pression et permet ainsi une analyse croisée entre les observations et les variations de perméabilité. Les expériences ont été réalisées pour différentes conditions hydrodynamiques (débit, mode de filtration) et conditions d'interactions colloïdales (en changeant la force ionique). Les résultats mettent en évidence l'importance de la dynamique du blocage de pore par des agrégats de particules et du réentrainement de ces agrégats lorsqu'ils sont fragilisés par l'écoulement. La dynamique de ces évènements provoque des fluctuations de perméabilité. Les interactions particule-particule ou particule-paroi jouent également un rôle important sur la dynamique du colmatage. Trois scenarios sont discutés par analogie anthropomorphique : un scenario panique (0.01 mM) où les répulsions entre les particules induit un phénomène de poussée entre particules qui engendre la formation d'arches à l'entrée des canaux ; un scenario instinct de troupeau (10 mM) où l'attraction entre particules (dans un minimum DLVO secondaire) facilite le transport dans le canal et retarde le colmatage ; un scenario sacrificiel (100 mM) où l'efficacité de capture des particules par les parois est élevée mais les agrégats formés sont très fragiles et fréquemment réentraînés par l'écoulement. Cette analyse illustre l'importance des phénomènes collectifs lors du colmatage par des particules inter-agissantes. Le mécanisme de colmatage par des particules biologiques (bactéries) et notamment la création de panaches bactériens en aval des canaux sont ensuite analysés. Ces phénomènes sont étudiés pour différentes conditions de culture (ratio carbone-azote dans le substrat) afin d'examiner l'effet de la production de substances polymériques extracellulaires (EPS) sur le colmatage. Les résultats montrent que les EPS (et donc les conditions de cultures) jouent un rôle crucial sur le développement de panaches bactériens lors d'écoulement dans des constrictions. Il est montré également que la filtration d'un mélange entre des bactéries produisant peu d'EPS et des bactéries produisant d'EPS favorise la formation des panaches bactériens. Des filtrations de mélange de bactéries et de particules montrent que la présence de bactérie modifie la dynamique du blocage des canaux ; de façon surprenante l'ajout de bactérie permet de retarder le colmatage et de former des dépôts de particules plus fragiles. Des systèmes microfluidiques avec un design spécifique ont également été développés pour réaliser un fractionnement par taille de dispersions sous un écoulement tangentiel. Des résultats préliminaires ont permis d'optimiser leur fonctionnement en trouvant des conditions permettant de filtrer en évitant le blocage des canaux ; leur utilisation pour réaliser des fractionnements continus dans des puces microfluidiques peut être envisagée. / The aim of the PhD is to progress in the understanding of the fouling phenomena during filtration of soft matter (colloidal particles and bacteria) and to examine the efficiency and feasibility of microfluidic separators. These studies are realized with microfluidic devices constituted of micrometric channels having the same size range as the materials being filtered. These devices, which mimic membrane dead-end and cross-flow microfiltration processes, allow in-situ and direct microscopic observations of the fouling mechanisms. The microfluidic system is equipped with flow rate and pressure measurement devices allowing a dynamic cross analysis of the observations with the variations of permeability. Experiments have been realized for different hydrodynamic conditions (flow rate, filtration mode) and for different colloidal interactions (by varying the ionic strength) in order to analyse their interplay in the clogging mechanism by soft matter (interacting particles). The results evidenced the importance of clogs formation, fragility and sweeping out dynamics during the fouling process. These dynamic events at bottlenecks induce important permeability fluctuations. The particle-particle and particle-wall interactions also play important roles on the clogging dynamics. Three different scenarios are discussed by analogy to crowd swarming: panic scenario (0.01 mM) where repulsion between particles induce pushing effects leading to the creation of robust arches at pore entrances; herding instinct scenario (10 mM) where the attraction (in secondary minima) between particles enhances the transport in pores and delays clogging; sacrifice scenario (100 mM) where the capture efficiency is high but the aggregates formed at the wall are fragile. These analyses illustrate the importance of collective behaviour exhibited by interacting particles during fouling. The fouling phenomena by biological particles (bacteria) are analysed in terms of the streamer formation conditions and mechanisms. The streamer formation phenomena are in turn analysed by playing with the cultivation conditions (the carbon to nitrogen ratio in the substrate) in order to study the effect of extracellular polymeric substances (EPS) on the process. The results show that EPS (and hence the bacterial cultivation conditions) play crucial role in streamer formation by microorganisms under flow in constrictions. Furthermore, the presence of non-EPS producing bacterial species along with EPS producing species in a mixed culture enhances the streamer formation. On the other hand, filtration of mixed particles and bacteria suspensions show that the presence of bacteria substantially modifies the clogging dynamics. Microfluidic devices with specific configurations have also been developed for fractionation in order to maximize performances of these processes. The preliminary results with these chips in cross-flow conditions show that it is possible to limit the clogging impact by working below a critical flux; their use for continuous microparticles fractionation could be then considered.

abstract: Large-scale cultivation of photosynthetic microorganisms for the production of biodiesel and other valuable commodities must be made more efficient. Recycling the water and nutrients acquired from biomass harvesting promotes a more sustainable and economically viable enterprise. This study reports on growing the cyanobacterium Synechocystis sp. PCC 6803 using permeate obtained from concentrating the biomass by cross-flow membrane filtration. I used a kinetic model based on the available light intensity (LI) to predict biomass productivity and evaluate overall performance. During the initial phase of the study, I integrated a membrane filter with a bench-top photobioreactor (PBR) and created a continuously operating system. Recycling permeate reduced the amount of fresh medium delivered to the PBR by 45%. Biomass production rates as high as 400 mg-DW/L/d (9.2 g-DW/m2/d) were sustained under constant lighting over a 12-day period. In the next phase, I operated the system as a sequencing batch reactor (SBR), which improved control over nutrient delivery and increased the concentration factor of filtered biomass (from 1.8 to 6.8). I developed unique system parameters to compute the amount of recycled permeate in the reactor and the actual hydraulic retention time during SBR operation. The amount of medium delivered to the system was reduced by up to 80%, and growth rates were consistent at variable amounts of repeatedly recycled permeate. The light-based model accurately predicted growth when biofilm was not present. Coupled with mass ratios for PCC 6803, these predictions facilitated efficient delivery of nitrogen and phosphorus. Daily biomass production rates and specific growth rates equal to 360 mg-DW/L/d (8.3 g/m2/d) and 1.0 d-1, respectively, were consistently achieved at a relatively low incident LI (180 µE/m2/s). Higher productivities (up to 550 mg-DW/L/d) occurred under increased LI (725 µE/m2/s), although the onset of biofilm impeded modeled performance. Permeate did not cause any gradual growth inhibition. Repeated results showed cultures rapidly entered a stressed state, which was followed by widespread cell lysis. This phenomenon occurred independently of permeate recycling and was not caused by nutrient starvation. It may best be explained by negative allelopathic effects or viral infection as a result of mixed culture conditions. / Dissertation/Thesis / Masters Thesis Civil and Environmental Engineering 2015

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / O uso de substrato de vidro para ser utilizado em sistema fotovoltaico à muito comum, no entanto, os substratos sÃo submetidos a elevadas temperaturas como no caso de obtenÃÃo de vidro recoberto com SnO2 (diÃxido de estanho), onde a temperatura de operaÃÃo atinge valores prÃximos a 600ÂC. Desta forma, um estudo do comportamento da dilataÃÃo do vidro em diferentes espessuras e sob a temperatura de 600ÂC foi realizado com o objetivo de observar a influÃncia dos mesmos nos vidros utilizados como substratos e, assim, prevenir os possÃveis defeitos de trinca e quebra de vidro dentro do forno. AlÃm do estudo associado ao vidro, um projeto teÃrico de um pirolisador com essas caracterÃsticas foi idealizado para a obtenÃÃo das camadas de SnO2 sobre o vidro, agregando inovaÃÃes como o uso de gÃs natural queimando em meio poroso como fonte de calor e o uso de um pirolisador para substituir os fornos resistivos. / The use of a glass substrate for use in photovoltaic system is very common, however, the substrates are subjected to high temperatures as in the case of obtaining glass covered with SnO2 (tin dioxide), where the operating temperature reaches values close to 600  C. Thus, a study of the glass expansion behavior with different thicknesses under temperature of 600  C was conducted in order to observe the influence of the same glass used as substrates, and thus, prevent possible defects cracks and broken glass inside the oven. Besides the study associated with the glass, a theoretical design of a pyrolyzer with these characteristics has been designed for obtaining layers of SnO2 on the glass, adding innovations such as the use of natural gas burning in porous media as heat source and the use of a pyrolyzer to replace the resistive furnaces.

Orientador: Roberto Testezlaf / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola / Made available in DSpace on 2018-08-17T14:05:19Z (GMT). No. of bitstreams: 1 SalcedoRamirez_JuanCamilo_M.pdf: 5267423 bytes, checksum: 8280ac47eb6e5c177b8a4533cedd1d53 (MD5) Previous issue date: 2010 / Resumo: O desempenho adequado de filtros de areia na irrigação localizada requer que os processos de filtração e retrolavagem sejam realizados de forma a reter as partículas em suspensão indesejadas e que a lavagem do meio filtrante retorne a operação do equipamento às suas condições originais de limpeza. A retrolavagem pode ser mais eficiente quando se atinge expansões homogêneas da camada com baixas perdas de pressão em função das características granulométricas da areia e da altura da camada filtrante. As faltas de experiência do produtor e de informações técnicas dos fabricantes determinam que a retrolavagem não seja realizada corretamente em campo, prejudicando a funcionalidade e eficiência dos filtros de areia. Neste contexto, o objetivo do presente trabalho foi desenvolver estudos sobre o comportamento das características hidrodinâmicas de pressão e vazão no processo da retrolavagem em filtros com variações nas características físicas da areia e nos componentes internos dos filtros. O trabalho foi dividido em três partes. Inicialmente, foi realizada, uma pesquisa de campo sobre os procedimentos e manejos utilizados pelos agricultores na execução da retrolavagem. Em uma segunda etapa, foi utilizada uma metodologia experimental para ensaios de laboratório em três filtros de areia convencionalmente usados no mercado brasileiro, para avaliar os efeitos de diferentes granulometrias da areia e diferentes alturas da camada filtrante sobre a perda de carga ao longo da camada e sobre o processo de fluidização do leito. Finalmente, na ultima parte, os resultados obtidos foram comparados com comportamento teóricos para estimativa da velocidade mínima de fluidização. Os procedimentos realizados pelos produtores demonstraram falta de conhecimento no processo da retrolavagem que é executado de forma empírica baseado em recomendações incorretas dos fornecedores. Experimentalmente, obteve-se que o processo de retrolavagem é afetado significativamente pela perda de pressão causada pelos componentes estruturais internos do filtro (crepina e difusor). As comparações dos resultados calculados a partir da equação de WEN & YU (1966) com os resultados experimentais, revelaram concordâncias explicitas para as granulometrias menores. A pesquisa permitiu concluir que a vazão da retrolavagem necessária para a expansão adequada do leito, aumenta proporcionalmente com as condições da altura da camada e da granulometria da areia / Abstract: The adequate sand filters performance in localized irrigation requires that filtration and backwash processes are capable to retain unwanted suspension particles and to wash properly the media depth, returning the equipment operation to its original condition of cleanliness. The backwash process can be more effective when it reaches bed uniform expansions with low head losses, which depends on the grain size and the depth of media bed. The lack of experience of farmers and technical information from the manufacturers determine that the backwash process has been performed incorrectly in the field, affecting adversely the functionality and efficiency of the sand filters. In this context, the objective of this study was to develop studies on the hydrodynamic behavior of the relationship of working pressure and flow rate in the backwash process of sand filters with variations in sand physical characteristics and the internal hydraulic components of the filters. This study was divided into three parts. Initially, a field survey on the farmers backwash procedures and management was performed. In a second step, an experimental methodology was developed to evaluate three commercial types of Brazilian sand filters to assess the effects of different grains diameters and media layer depths on the head losses and the process of layer fluidization. Finally, the experimental results of the minimum fluidization velocity were compared with estimated values using the theoretical behavior of the process. The results showed that the procedures performed by the producers showed a lack of knowledge in the backwash process, which is executed based on empirical basis, oriented by imprecise information of suppliers. The experimental part demonstrated that the backwash process is affected significantly by the head loss originated from the internal structural components of the filter (underdrain and diffuser). The mathematical comparisons of the experimental results with the values estimated by the equation & WEN YU (1966) showed explicit agreements for smaller particle size. The research allowed concluding that the values backwash flow rate required for an adequate expansion, increases proportionally with the depth and the particle size of sand layer / Mestrado / Agua e Solo / Mestre em Engenharia Agrícola

Tendo em vista a existência de muitas comunidades no Estado de São Paulo (e em outros estados do Brasil), que utilizam água muitas vezes com qualidade imprópria ao consumo humano, o presente trabalho visa o desenvolvimento de uma instalação de filtração utilizando Carvão Ativado Impregnado com Prata (CAIP) com o intuito de eliminar alguma contaminação na água tratada devido à problemas tais como anomalias operacionais na ETA, tecnologia de tratamento inadequada, contaminação da rede de distribuição, reservação, dentre outros. Para a investigação experimental foram preparados três tipos de água de estudo, com baixos valores de turbidez e cor aparente. A água tipo I era isenta de contaminação, as águas tipo II e III apresentaram coliformes totais e fecais, sendo que a água tipo III utilizada na simulação da instalação como filtro domiciliar. Os ensaios realizados apresentaram taxa de filtração entre 200 e 250 m3/m2*d. Os resultados indicam que o CAIP apresentou propriedades adsorventes e é um poderoso agente desinfetante, reduzindo significativamente o NMP de coliformes totais e fecais de águas contaminadas. Porém, a desinfecção não foi completa e ocorreu excessivo desprendimento da prata do CAIP, inviabilizando o uso deste CAIP nesta instalação desenvolvida. / Minding the existence of many communities within the state of São Paulo (and other Brazilian states) which often use water unfit for human consumption, this work aims at the development of a filtering installation that uses Activated Carbon supporting Silver (AC(Ag)) in an attempt to eliminate any contamination in treated water. Such water contamination problems include, operational anomalies in the WTP, inadequate treatment technologies, contamination in the distribution net, and other filter specific problems. For the experimental investigation three types of test water were prepared, with low turbidity and apparent color values. Water type I was contarnination-free, water type II and III had total and fecal coliforms, and water type III was used in the simulation of domestic filtering installation. Tests showed a filtering rate between 200 and 250 m3/m2*d. Results point that AC(Ag) has adsorbent capabilities, in addition to being a powerful disinfection agent, and reduced significantly the number of total and fecal coliforms of contaminated waters. However, disinfection was not thoroughly, and silver was excessively dragged away, from the Activated Carbon, thus rendering the use of AC(Ag) unadvisable in the developed installation.

Orientadores: José Flávio Affonso de Almeida, Caio Cezar Randi Ferraz / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-19T18:53:10Z (GMT). No. of bitstreams: 1 Nicastro_KarineSchelldeMoraes_M.pdf: 1993293 bytes, checksum: 8a68234b96ec379b86f37b8d3aa3f18b (MD5) Previous issue date: 2012 / Resumo: O objetivo desse estudo foi avaliar o preenchimento e selamento apical da obturação com cones de guta-percha de diferentes conicidades, após o preparo químico-mecânico com batente apical e preparo cônico contínuo. Foram utilizadas 90 raízes mesiais de molares inferiores com dois canais e forames distintos. As raízes foram divididas em seis grupos de acordo com o preparo apical: Grupos 1, 2 e 3 - preparo com batente apical e nos Grupos 4, 5 e 6 - preparo cônico contínuo. Todos os grupos foram instrumentados com o sistema rotatório K3. A obturação foi feita com a Técnica Onda Contínua de Condensação, utilizando três tipos de cones de guta-percha não estandartizados: Fine, Fine-Medium e Medium. Analisou-se a micro infiltração apical, através da Filtração de Fluidos, em apenas um dos canais da raiz mesial utilizando o Flodec. Verificou-se o preenchimento dos cones de guta-percha no interior do canal à 1,5, 2,5 e 3,5 mm do forame apical, utilizando a lupa estereoscópica com aumento de 20x. Foram comparados em cada corte a área de guta-percha obturada em relação à área instrumentada; à área total do canal radicular e à área de falhas presentes nas obturações. Para microinfiltração apical não houve diferença estatística entre os grupos testados. Quando analisada a área ocupada pela guta-percha em relação à área instrumentada, à área total e à área de falhas entre os diferentes cortes (1,5, 2,5 e 3,5) no mesmo grupo em ambos os preparos não houve diferença estatística. Em contraposição quando foi considerado à área instrumentada, no grupo 5 houve diferença estatística comparando os cortes 1,5 e 2,5mm. Para área total, no grupo 2, obteve-se diferença nos cortes a 1,5 e 2,5mm. Quando se considerou o mesmo corte (1,5, 2,5 e 3,5) para os diferentes grupos, particularmente para área instrumentada, o Grupo 5 apresentou melhores resultados que o Grupo 4 no corte à 1,5mm. Para a área total, nível de corte 1,5mm, o Grupo 5 apresentou melhor adaptação da guta-percha do que o Grupo 6. Os cones de diferentes conicidades demonstraram adaptações semelhantes tanto no preparo com batente apical tanto no preparo cônico contínuo. A presença ou ausência do batente apical, a conicidade e adaptação dos cones de guta-percha e o diâmetro do forame apical não influenciaram o selamento apical da obturação / Abstract: The aim of this study was to evaluate the adaptation and apical sealing of the root canal filling with gutta-percha using different tapers with an apical stop or continuous preparation technique. Ninety mesial roots of mandibular molars with two canals ending in distinct forame were used. The roots were divided into six groups according to instrumentation technique: Groups 1, 2 and 3 - using apical stop; and groups 4, 5 and 6 - performed with the Continuous Preparation. Root canal preparation was performed with K3 rotary file system. The continuous wave technique of condensation was used for root canal filling, using three different tapered gutta-percha: Fine, Fine-Medium and Medium. First, apical microleakage was tested by fluid filtration in one of the mesial root canals. Secondly, the adaptation of gutta-percha was investigated at the 1.5, 2.5 and 3.5 mm from the apical foramen using stereomicroscope with 20x. The sections were compared considering area filled with gutta-percha, in relation to the instrumented area, the total area of the root canal and the area of gaps present in root fillings. Apical microleakage showed no statistical difference among the groups tested. When analyzing the area occupied by gutta-percha to instrumented area, total area and area of gaps among the different sections (1.5, 2.5 and 3.5) in the same group in both preparations there was no difference statistical. In contrast when it was considered in the instrumented area in Group 5, no statistical difference comparing the sections 1.5 and 2.5 mm. For the total area, in group 2, we obtained difference in the sections at 1.5 and 2.5 mm. When we considered the same section (1.5, 2.5 and 3.5) for the different groups, particularly for field instruments, the group 5 showed better results than in Group 4 cut to 1.5 mm. For the total area, 1.5 mm section level, the Group 5 showed better adaptation of gutta-percha than Group 6. The cones of different taper showed similar adaptions in both apical stop preparation and continuous tapered preparation. The presence or absence of the apical stop, taper and adaptation of gutta-percha and the diameter of apical foramen did not affect the apical seal the filling / Mestrado / Endodontia / Mestre em Clínica Odontológica