When microfiltration (MF) and ultrafiltration (UF) membranes are applied for drinking water treatment/wastewater reuse, membrane fouling is an evitable problem, causing the loss of productivity over time. Polymeric membranes have been often reported to experience rapid and/or problematical fouling, restraining sustainable operation. Ceramic membranes can be effectively employed to treat impaired-quality source waters due to their inherent robustness in terms of physical and chemical stability. This research aimed to identify the effects of coagulation and/or ozonation on ceramic membrane filtration for seawater and wastewater (WW) effluent. Two different types of MF and UF ceramic membranes obtained by sintering (i.e., TAMI made of TiO2+ZrO2) and anodic oxidation process (i.e., AAO made of Al2O3) were employed for bench-scale tests. Precoagulation was shown to play an important role in both enhancing membrane filterability and natural organic matter (NOM) removal efficacy for treating a highorganic surface water. The most critical factors were found to be pH and coagulant dosage with the highest efficiency resulting under low pH and high coagulant dose. Due to the ozone-resistance nature of the ceramic membranes, preozonation allowed the ceramic membranes to be operated at higher flux, especially leading to significant flux improvement when treating seawater in the presence of calcium and magnesium. 4 Dissolved ozone in contact with the TAMI ceramic membrane surface accelerated the formation of hydroxyl (˙OH) radicals in WW effluent treatment. Flux restoration of both ceramic membranes, fouled with seawater and WW effluent, was efficiently achieved by high backwash (BW) pressure and ozone in chemically enhanced backwashing (CEB). Ceramic membranes exhibited a pH-dependent permeate flux while filtering WW effluent, showing reduced fouling with increased pH. On the other hand, for filtering seawater, differences in permeate flux between the two membranes was observed under basic pH conditions, showing that the TAMI membrane flux was stable regardless of changes in pH, while the AAO membrane flux was significantly decreased as pH increased to 10. Consequently, it is expected that ozone and/or coagulation prior to ceramic membrane filtration can play a significant role in treating impaired-quality source waters (e.g., seawater and WW effluent), leading to maintaining sustainable membrane flux in seawater pretreatment before reverse osmosis (RO) or water reuse applications.

<p>In this research, ozone hydrodynamics and disinfection by-products formation in a novel hybrid ozonation-ceramic membrane filtration system was studied to minimize membrane fouling while also ensuring that the system meets regulatory criteria for disinfection by-products. The influence of important operating parameters including inlet ozone mass injection rate, initial bromide concentration, membrane molecular weight cut off (MWCO), membrane coating, hydroxyl radical scavenger (<em>t</em>-butanol), pH, and temperature on bromate concentration in the absence and presence of natural organic matter (NOM) was examined. Experiments were also conducted under various operating conditions to investigate the formation of total trihalomethanes (TTHMs) and halo-acetic acids (HAAs) in the water distribution system due to post chlorination. Moreover, variations in the TOC, UV₂₅₄, color and turbidity with respect to operating parameters were monitored.</p> <p>Bromate and TTHMs formation increased with increasing ozone mass injection rate, and initial bromide concentration. An increase in the bromate concentration was observed with decreasing membrane MWCO. Less bromate and TTHM was formed with the coated membrane and <em>t</em>-butanol significantly reduced bromate and TTHM formation. Bromate formation decreased significantly with decreasing pH. Increasing the temperature resulted in enhanced bromate formation. NOM exerted a favorable effect on bromate formation as the bromate concentration was observed to decrease as the NOM content was increased.</p> <p>Experimental results indicated that ozonation can greatly reduce color and turbidity of water and can be used to overcome membrane fouling. Ensuring a minimum ozone residual in the system enables the continuous treatment of water at a relatively high permeate flux (up to 85% of the clean water flux) and eliminates the need for membrane cleaning procedures.</p> <p>An empirical model was developed to predict bromate formation in the hybrid ozone- membrane system (R²=0.903). Theoretical models were developed to estimate the rate of bromate formation and to describe the ozone mass transfer in a hybrid system. In all cases, good correlation between the model predictions and the experimental data was achieved.</p> / Doctor of Philosophy (PhD)

O fluido multifásico complexo (suco de açaí) tem uma forte interação com membranas poliméricas ou cerâmicas de microfiltração e a formação de incrustação depende da composição e das condições de dinâmica de fluidos. Neste estudo experimental foi investigada a influência dos dois principais ácidos graxos presentes no açaí, ácido oleico e ácido palmítico, em misturas com água e no processo de microfiltração tangencial com membranas cerâmicas de alumina com um tamanho de poro nominal de 0,2 \'mü\'m. Mediu-se o fluxo de permeado em função do tempo, nas pressões transmembranas de 300 kPa, 400 kPa e 500 kPa. Para o fluxo da corrente de alimentação foram encontrados valores de Reynolds numa faixa de 9500 a 31000. Cada amostra de misturas de água/ácido oleico, água/ácido palmítico e água/ácidos oleico e palmítico, foi estudada em três séries de ensaios realizados durante 180 minutos e 72 minutos para a mistura água/ácido palmítico, a temperatura em 25 ºC. Analisou-se as incrustações resultantes e as fortes interações fluido/membrana utilizando o modelo de resistência em série e imagens tomadas por microscopia eletrônica de varredura (MEV). Os melhores resultados de permeado encontrados para a mistura de água/ácido oleico foram para Re = 33000, no entanto, resultados satisfatórios foram encontrados para Re = 20000. Agora para a água/ácido palmítico foram encontrados para Re = 20000. Os melhores resultados de permeado para a mistura água/ácidos oleico e palmítico foram para Re = 31000. De acordo com os resultados das resistências, a mistura água/ácido causa um bloqueio dos poros da membrana, resultando em uma maior diminuição do fluxo transmembrana. A limpeza foi eficiente para reduzir a resistência associada com a polarização. / The complex fluid multiphase (açaí juice) has a strong interaction with polymeric or ceramic membranes for microfiltration fouling and its formation depends on the fluid composition and fluid dynamics conditions. In this experimental study was investigated the influence of two major fatty acids present in açaí, oleic acid and palmitic acid in mixtures with water and in the process of crossflow microfiltration with ceramic membranes. In the separation process is used alumina ceramic membrane with a nominal pore size of 0.2 micrometers. The permeate flux was measured in function of time using the 300 kPa, 400 kPa and 500 kPa for the transmembrane pressure. The flow of feed stream and its respective value of Reynolds were in range of: 8900-3300. For each sample of mixtures oleic acid/water and palmitic acid/water and palmitic acid, oleic acid/ water, three series of experiments were conducted for 180 minutes and 72 minutes for mixture palmitic acid/water at temperature in 25 Celcius. For analyze of fouling resulting from strong interactions fluid/membrane was used the model of resistance in series and images taken via scanning electron microscopy (SEM). The best results for mixing oleic acid/water were to Re = 33000, however, satisfactory results were found for Re = 20000. Now for the palmitic acid/water were found to Re = 20000. For mixture palmitic acid, oleic acid/ water were found to Re = 31000. According to the results of the resistances, the mixture oleic acid/water cause a blockage of the pores of the membrane resulting in a greater decrease of the transmembrane flow. The cleaning is efficient for reducing the resistance associated with the polarization.

Nesta pesquisa de doutorado, o processo de microfiltração tangencial com membranas cerâmicas é investigado visando à retenção de bactérias (Escherichia coli CCT 0549) e redução de sólidos suspensos de uma bebida à base de açaí (Euterpe oleracea Mart.). As membranas comerciais selecionadas foram manufaturadas com \'alfa\'-alumina (\'AL IND.2\'O IND.3\') e possuem tamanho nominal de poro, fornecido pelo fabricante no valor de 0,8\'mü\'m e 1,2\'mü\'m. O valor nominal da membrana de 1,2\'mü\'m é maior que a largura da Escherichia coli (0,8\'mü\'m). Como, a princípio, o microrganismo está fisicamente sujeito a passagem pela membrana de 1,2\'mü\'m, esta estrutura micro-porosa foi submetida à impregnação de prata. Este procedimento visou verificar a influência da prata como material bactericida para auxiliar na redução/eliminação das bactérias inoculadas na bebida à base de açaí. Para tanto, a estrutura cerâmica micro-porosa foi tratada quimicamente com solução de citrato de prata e submetida à queima até a temperatura de 600 graus Celsius para eliminação dos compostos orgânicos e conseqüente impregnação de nanopartículas de prata metálica nos poros da membrana. Este processo de impregnação proporcionou um discreto aumento no índice de retenção microbiana em regime de escoamento turbulento (Re=20000). A caracterização morfológica, a composição e a impregnação de prata nas membranas foram realizadas com o auxílio da Microscopia Eletrônica de Varredura (MEV) e do Detector de Energia Dispersiva de Raio-X (EDX). Estas mesmas técnicas foram utilizadas para caracterizar o fenômeno físico-químico de formação da camada polarizada sobre a superfície da membrana. A análise da retenção de bactérias foi realizada através da contagem de unidades formadoras de colônia (UFC/mL) em placas Petrifilm \'EC POT.TM\'. O desempenho das membranas na retenção de material particulado suspenso foi analisado pela técnica de espectroscopia de ultra-som e por comparação qualitativa, entre concentrado e permeado, via microscopia ótica. A redução de antocianina (cianidina-3-glicosídeo) e o conteúdo de polifenóis totais foram investigados via espectrofotometria, apresentando relação direta com o tamanho dos poros da membrana e com o regime de escoamento. Desta forma, parâmetros fluido-dinâmicos do processo, tais como: número de Reynolds, pressão transmembrana e fluxo transmembrana foram caracterizados para uma ampla faixa do escoamento turbulento e analisados com o modelo de resistência em série. Os resultados experimentais obtidos neste trabalho indicaram que o processo de microfiltração tangencial é uma boa alternativa à retenção de microrganismos e simultânea redução de sólidos suspensos da bebida à base de açaí. / In this doctoral research, the crossflow microfiltration process utilizing ceramic membranes was investigated aiming at the bacteria retention (Escherichia coli) and reduction of suspended solids of beverage based on açai (Euterpe oleracea Mart.). The selected commercial membranes of \'alfa\'-alumina (\'AL IND.2\'O IND.3\') had nominal pore sizes of 0.8 and 1.2 \'mü\'m and were manufactured by Andritz Group from Austria. The membrane nominal value of 1.2\'mü\'m is larger than the width of the Escherichia coli (0.8\'mü\'m). Therefore, as the microrganisms are subjected to pass through the pores of this membrane, it was submitted to silver impregnation. This procedure aimed to verify the silver influence as a bactericide material to assist in retention or elimination of bacteria during the microfiltration process. In this way, the microporous structure was chemically treated with a silver citrate solution and then, subjected to burning until 600 Celsius degrees to eliminate organic compounds and consequent impregnation of nanoparticles of metallic silver in the membrane pores. The morphology characterization, composition, and impregnation of silver in membranes were analyzed by Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray fluorescence (EDX) spectrometer. The same techniques were utilized to characterize the physicochemical phenomenon of polarization layer formation on the membrane surface. The analysis of bacteria retention was performed by the counting of colony forming units (CFU/mL) in Petrifilm Plates \'EC POT.TM\'. The performance of the membranes in the retention of solids in suspension was analyzed by Ultrasound Spectroscopy - APS100 and Optical Microscopy. The variations of the anthocyanin concentration and the total polyphenol content were investigated by spectrophotometry, showing direct relationship with the membrane pore size and flow regime. Therefore, fluid-dynamical parameters, such as Reynolds number, transmembrane pressure, and permeate flux were characterized for a large range of turbulent flow and analyzed with the resistance-in-series model. The experimental results of this research indicated that the microfiltration process is a suitable alternative to retain microrganisms and simultaneously decrease suspended solids of the beverage based on açai.

Water resources are increasingly precious, so wastewater reclaiming has become an important source of water nowadays. There are many types of industry including conventional and hi-tech ones in the selected industrial processing zone, where different process wastewaters are treated by a centralized wastewater treatment plant. The effluent is then discharged into the ocean (EDO). On the other hand, among several other industries backside grinding (BG) wastewater generated by the IC (integrated-circuit) packaging and testing industry is treated by their owned wastewater treatment plants and then discharged onto land (EDL). Normally, BG wastewater is huge in quantity and it contains microscale and nanoscale particles. The objectives of this research were two-fold: (1) to evaluate the feasibility of using two tubular ceramic membranes (microfiltration and ultrafiltration) coupled with the electrocoagulation/electrofiltration (EC/EF) process to effectively treat the effluent discharged into the ocean, effluent discharged onto land, and BG wastewater for the purpose of reclamation; and (2) to investigate the best time for backwashing of membranes through the analysis of components of membrane fouling using resistances in series model. The experimental results showed that the ultrafiltration (UF) membrane (i.e., tubular TiO2/Al2O3 composite membrane) outperformed the mictrofiltration (MF) membrane (i.e., tubular Al2O3 membrane) in terms of permeate quality. But, generally, the later yielded a greater membrane flux. In the case of BG wastewater by UF and EC/EF, the quality of permeate met the tap water standards in terms of water quality items analyzed. As for EDO and EDL further treated by UF and EC/EF, all the analyzed water quality items of permeate, except pH and total dissolved solids, met the tap water standards in Taiwan. Thus, more efforts have to be made to reclaim these two types of effluent. Finally, the components of membrane fouling were analyzed using resistances in series model for the tested water specimens. The results showed that generally the irreversible resistance component (Rirr) had a greater contribution to a better quality of permeate than that of the reversible resistance component (Rr). It was also found that the magnitude of Rirr of BG wastewater was greater than Rirr values of the other two effluents. This might explain why the quality of permeate of the former was better than the latter. The results further indicated that Rr increased more than Rirr as the operating time elapsed, resulting in a limited improvement of permeate quality even a longer treatment time was employed. To recover the membrane flux to its optimum, in this study the best time for backwashing of membrane was determined based on the time at which Rr was greater than Rirr. However, the flux recovery was found to be in the range of 60-77% as compared with the initial flux for a virgin membrane in treating new batch of water specimens. The fraction unable to recover by backwashing might be contributed by Rirr in the membrane pores. A further acid washing would resolve this problem.

Submitted by Gustavo Nascimento (gustavo.diniz@ufcg.edu.br) on 2018-02-07T12:18:32Z No. of bitstreams: 1 RAISSA MENEZES DE SOUSA - DISSERTAÇÃO PPGEQ 2016.pdf: 3574277 bytes, checksum: fc3f9b72fefbf347de741a28f9bed6b6 (MD5) / Made available in DSpace on 2018-02-07T12:18:32Z (GMT). No. of bitstreams: 1 RAISSA MENEZES DE SOUSA - DISSERTAÇÃO PPGEQ 2016.pdf: 3574277 bytes, checksum: fc3f9b72fefbf347de741a28f9bed6b6 (MD5) Previous issue date: 2016 / Capes / Diversas tecnologias tem sido utilizadas para tratamento da água produzida (mistura água/óleo). Os processos de separação por membranas (PSM) apresentam vantagens sobre outros métodos tradicionais de separação, contudo alguns problemas operacionais atrelados aos PSM, como polarização por concentração, fouling e formação da camada gel, causam o decréscimo do fluxo permeado com o tempo. Sob condições onde os efeitos da polarização por concentração são mínimas, o escoamento será afetado pela pressão transmembrana. Assim, foi realizado um estudo da fluidodinâmica de uma mistura água/óleo utilizando membrana cerâmica, com auxílio do software ANSYS CFX® Release 15.0. Foi desenvolvido um modelo matemático com um fluido incompressível escoando em regime turbulento. As equações de momento linear, conservação e transporte de massa foram resolvidas com o auxílio de uma malha estruturada. Os resultados da simulação apresentaram os seguintes resultados: a modelagem matemática previu numericamente o processo de filtração tangencial via membrana cerâmica no tratamento de água produzida; observou-se que em vazões muito baixas há uma maior concentração de óleo próximo a membrana enquanto em vazões elevadas, o óleo fica disperso na mistura, onde há a quebra da camada limite; os efeitos viscosos não apresentam diferenças significativas nos perfis de concentração e velocidade. / Several technologies have been used to treat the water produced (water / oil mixture). Membrane separation processes (PSM) have advantages over other traditional methods of separation, however, some operational problems related to PSM, such as polarization by concentration, fouling and formation of the gel layer, cause a decrease in permeate flow over time. Under conditions where the effects of concentration polarization are minimal, the flow will be affected by transmembrane pressure. Thus, a study of the fluid dynamics of a water / oil mixture using ceramic membrane was carried out with the help of ANSYS CFX® Release 15.0 software. A mathematical model was developed with an incompressible fluid flowing in a turbulent regime. The equations of linear momentum, conservation and mass transport were solved with the aid of a structured mesh. The results of the simulation presented the following results: mathematical modeling numerically predicted the process of tangential filtration via the ceramic membrane in the treatment of produced water; it was observed that in very low flows there is a higher concentration of oil near the membrane while at high flow rates the oil is dispersed in the mixture, where the boundary layer is broken; the viscous effects do not present significant differences in the concentration and velocity profiles.

Submitted by Lucienne Costa (lucienneferreira@ufcg.edu.br) on 2018-04-04T19:21:47Z No. of bitstreams: 1 HORTÊNCIA LUMA FERNANDES MAGALHÂES - DISSERTAÇÃO (PPGEM) 2017.pdf: 3450368 bytes, checksum: f5d98ccec242bacb7a52e66286aa05ee (MD5) / Made available in DSpace on 2018-04-04T19:21:47Z (GMT). No. of bitstreams: 1 HORTÊNCIA LUMA FERNANDES MAGALHÂES - DISSERTAÇÃO (PPGEM) 2017.pdf: 3450368 bytes, checksum: f5d98ccec242bacb7a52e66286aa05ee (MD5) Previous issue date: 2017-04-27 / Capes / A crescente preocupação com o meio ambiente, em especial ao descarte adequado de efluentes industriais, vem despertando a atenção de pesquisadores e engenheiros que visam minimizar essa problemática e atender as exigências dos órgãos de controle ambiental. Os processos de separação utilizando membranas cerâmicas têm se destacado neste cenário como uma importante ferramenta de tratamento de aguas contaminadas, devido ao seu custo-benefício, longa vida útil e baixo consumo de energia. Neste sentido, avaliou-se empregando a fluidodinâmica computacional (CFD), o efeito térmico no processo de separação água/óleo via membrana cerâmica. Adotou-se o modelo de resistências em série em conjunto com as equações de conservação de massa, momento linear e energia, que foram resolvidas usando o ANSYS CFX® 15. Os resultados numéricos mostram que o modelo matemático utilizado é capaz de prever a formação e crescimento da camada limite de concentração ao longo da membrana tubular, como também a permeação do soluto (óleo) na membrana. / The growing concern with the environment, especially the adequate disposal of industrial effluents, has been attracting the attention of researchers and engineers that aim to minimize this problem and meet the requirements of environmental control agencies. The separation processes using ceramic membranes have stood out in this scenario as an important tool of treatment of contaminated water, due to their cost-benefit, long life and low energy consumption. In this sense, it was evaluated using the computational fluid dynamics (CFD), the thermal effect in the water / oil separation process via ceramic membrane. The series resistance model was adopted in conjunction with the conservation equations of mass, linear momentum and energy, which were solved using ANSYS CFX® 15. The numerical results show that the mathematical model used is able to predict the formation and growth of the boundary layer of concentration along the tubular membrane, as well as the permeation of the solute (oil) in the membrane.

En compétition avec les alcanolamines, les liquides ioniques (LIs) sont connus pour interagir fortement et de façon réversible avec des gaz acides. Les propriétés remarquables des LIs ont conduit à la réalisation de ‘Supported Ionic Liquid Membranes’ (SILMs) qui sont des systèmes continus attractifs pour la séparation de gaz, et notamment du CO2. Dans les SILMs, il est possible d’adapter les propriétés d'adsorption/séparation en modifiant les caractéristiques du support (e.g. composition, structure poreuse, surface spécifique, etc.) et du LI (nature des cations et anions). En dépit de leur relative instabilité dans les procédés de séparation de gaz acides, les supports nanoporeux polymériques sont classiquement utilisés pour préparer des SILMs. Récemment, les supports céramiques poreux ont été considérés pour la réalisation de SILMs en raison de leurs excellentes résistances thermique et mécanique. La plupart de ces systèmes sont préparés par imprégnation/infiltration des LIs dans les pores du support céramique. Ce protocole conduit à la formation de matériaux composites dans lesquels le LI est physiquement piégé dans le support, mais souvent avec une distribution hétérogène du LI et une stabilité limitée dans le temps. Dans ce travail de thèse, réalisé en collaboration entre l’Institut Européen des Membranes (IEM) et l’Institut Charles Gerhardt de Montpellier (ICGM), nous avons développé une nouvelle génération de SILMs, dans lesquelles le LI est confiné dans les pores d'un support en céramique mésoporeux par greffage chimique. La préparation de ces systèmes se fait en trois étapes :i) Synthèse et caractérisation de nouveaux LIs portant des fonctions de couplage pour assurer leur greffage en surface des pores de la membrane céramique et détermination de la capacité d’absorption du CO2 des différents LIs synthétisés;ii) Optimisation des paramètres de greffage de ces LIs sur des poudres modèles de γ-Al2O3 et caractérisation des matériaux hybrides obtenus avec mise en évidence du greffage;iii) Transfert du protocole de greffage optimisé sur des membranes céramiques commerciales γ-alumine (fabrication de Grafted Ionic Liquid Membranes - GILMs) et évaluation de leurs performances pour la séparation du CO2.Ce travail, basé sur une approche originale, associant de nouveaux liquides ioniques et un nouveau concept de membrane à base de liquide ionique supporté, montre, au travers de plusieurs exemples l’intérêt d’une approche multi-étapes pour le développement de systèmes membranaires de séparation du CO2. / In competition with amines, ionic liquids (ILs) are known to interact strongly and reversibly with acid gases, making supported IL-membrane (SILMs) versatile materials for use in CO2 membrane separation applications. It is possible to finely tune SILMs properties for CO2 adsorption/separation by tailoring the characteristics of both the support (e.g., porosity, surface area, composition, etc.) and the ionic liquid (cations and anions). Up to now, nanoporous polymer supports have been favored for preparing SILMs, in spite of their relative instability during continuous separation processes in the presence of acidic gases. Recently, porous ceramic supports have been considered due to their excellent thermal and mechanical resistance. Most of the SILMs are prepared by impregnation/infiltration of IL in the pores of ceramic support which leads to the formation of composite membrane materials with either a physisorbed or mechanically trapped IL in the support. Despite their promising performance, such SILMs exhibit inherent limitations such as facile IL disarrangement, heterogeneous distribution, and limited stability upon ageing.In this Ph.D work, carried out in collaboration between the Institut Européen des Membranes (IEM) and the Institut Charles Gerhardt de Montpellier (ICGM), a new generation of SILMs has been developed in which ILs are confined within the pores of a mesoporous ceramic support by chemical grafting. The membranes are prepared in three steps:i) Synthesis and characterization of new ILs bearing a coupling function which allow the grafting on the surface of ceramic oxide supports and determination of the CO2 absorption capacity of the new ILs developed;ii) Elaboration and/or optimization of relevant synthesis protocols for grafting ILs on/in γ-alumina powders and physico-chemical characterizations of the hybrid materials;iii) Transfer of the optimized grafting protocols on commercial porous ceramic support with γ-alumina top-layer to produce Grafted Ionic Liquid Membranes (GILMs) and evaluate their performance for CO2 separation.An original research strategy, based on new ionic liquids and innovative membrane concepts have been addressed in this work, illustrating the contribution of a multi-step approach towards the development of membranes for CO2 separation.

Submitted by Maria Medeiros (maria.dilva1@ufcg.edu.br) on 2018-09-13T15:23:53Z No. of bitstreams: 1 JOSEDITE SARAIVA DE SOUZA - TESE (PPGEP) 2014.pdf: 5001055 bytes, checksum: b013c909ca0b39d1d6548d97afc484ce (MD5) / Made available in DSpace on 2018-09-13T15:23:53Z (GMT). No. of bitstreams: 1 JOSEDITE SARAIVA DE SOUZA - TESE (PPGEP) 2014.pdf: 5001055 bytes, checksum: b013c909ca0b39d1d6548d97afc484ce (MD5) Previous issue date: 2014-02-24 / Tecnologias inovadoras são necessárias para atender as normas de tratamento de águas produzidas cada vez mais rígidas, visto que a maioria dos processos de separação é limitada a partículas superiores a 10 m. Os processos de separação utilizando membranas cerâmicas veem despertando grande interesse da comunidade acadêmica e industrial. Mesmo assim, têm sido reportados poucos estudos, especialmente numéricos, referentes à aplicação de membranas inorgânicas na separação água/óleo. Nesse sentido, realizou-se um estudo da fluidodinâmica do escoamento de fluidos em tubos permeáveis (membrana cerâmica porosa tubular), em regime laminar. As equações de conservação de massa, momento linear e transporte de massa foram resolvidas com auxilio de uma malha estruturada usando o pacote comercial ANSYS CFX 12. A velocidade de permeação local foi determinada usando o modelo das resistências em série. A resistência específica da camada polarizada foi obtida pela equação de Carman-Kozeny. Os resultados numéricos foram comparados e avaliados utilizando-se de resultados analíticos e numéricos disponíveis na literatura apresentando boa concordância entre si. Os resultados numéricos indicam que, ao se utilizar o módulo de separação casco/membrana tubular proposto, há um favorecimento da transferência de massa e uma redução da espessura da camada limite polarizada. / Innovative technologies are needed to attend the requirements increasingly strict for produced waters treatment, whereas the most separation processes are limited to particles larger than 10 μm. Separation processes using ceramic membranes is attracting great interest from academic and industrial community. Nevertheless, it has been reported few studies, especially numerical, regarding the inorganic membranes application in the separation water/petroleum. Accordingly, a study of fluid-flow dynamics in porous tubes (tubular porous ceramic membrane) was performed, in a laminar regime. The mass, momentum and mass transport conservation equations were solved with the aid of a structured mesh using ANSYS commercial package CFX 12. The permeation velocity local was determined by using the resistance in series model. The specific resistance of the polarized layer was obtained by Carman-Kozeny equation. The numerical results were compared and evaluated using analytical and numerical results available in the literature presenting good agreement with each other. The numerical results indicate that, using the proposed separation module (shell / tube membrane), there is a mass transfer favoring and a reduction in the thickness boundary layer polarized.

The aim of this work was to obtain buffalo whey from a standard cheese curd production, with the evaluation of their efficiency in relation to the cow milk. The buffalo whey was characterized by nutritional information and microbial aspects. It was compare the efficiency of the microfiltration process of whey with the traditional pasteurization process. To carry out the microfiltration process of buffalo whey, it was used a tubular ceramic alumina membrane (0.8&#956;m of pore size), made in laboratory in Materials Engineering Department, at Federal University of Campina Grande. It was done seven tests and the samples of whey were analyzed after production (SA), after microfiltration process (SF) and after pasteurization process (SP). It was studied the followed physical-chemistry: pH, density, acidity, humidity, total dry extract, fat, lactose and protein content, according to recommended methodology from Instituto Adolfo Lutz, 2005, and the microbiological parameter: aerobic mesophilic bacteria measurement was done by Petri film plates, according to AOAC, 2000. The results showed that the performance of the cheese curd from buffalo milk was 27.51% and the one from cow milk was 13.06%. The characterization of the whey showed the followed results: 89.94% of humidity, 10.06% of total dry extract, 6.29 of pH, 1.029 of density, 10.07oD of acidity, 1.37% of fat, 1.19% of protein and 5.84% of lactose. After microfiltration and pasteurization process the samples of whey showed a reduction of bacterial count to 4.04 log UFC/mL to SA, 1.5 log UFC/mL to SP and 0.70 log UFC/mL to SF. In relation to the physical-chemistry parameters, it was showed great loss of nutritional content of the whey sample after microfiltration process when compared with the pasteurization process. So, despite the microfiltration by ceramic membrane is more efficiency then the pasteurization process to remove the microbial content, there is a need to improve the process to avoid fouling on the membrane surface that is responsible by the nutrients reduction. / O objetivo deste trabalho foi, a partir da padronização da produção de queijo coalho de búfala em laboratório, avaliar seu rendimento em relação ao leite de vaca, obter o soro de leite e caracterizá-lo quanto ao seu valor nutricional e de carga microbiana, antes e após o tratamento por microfiltração ou pasteurização. Para realizar o processo de microfiltração do soro de leite de búfala, utilizou-se uma membrana cerâmica tubular de alumina (0,8 &#956;m de porosidade), confeccionada em laboratório do departamento de materiais (DEMA) da UFCG. Foram realizados sete ensaios e analisadas físico-químicas e microbiologicamente amostras de soro in natura (SA), do soro filtrado (SF) e do soro pasteurizado (SP). Os parâmetros físico-químicos avaliados foram: pH, densidade, acidez, umidade, extrato seco total, teor de gordura, lactose e proteínas totais segundo metodologia recomendada pelo Instituto Adolfo Lutz (2005). Também foram realizadas contagens de bactérias aeróbias mesófilas utilizando placas Petrifilm, de acordo com metodologia da AOAC (2000). Os resultados obtidos indicaram que o rendimento médio de produção de queijo coalho a partir de leite búfala foi de 27,51%, enquanto com a utilização de leite de vaca pasteurizado, este rendimento foi de 13,06%. Quanto à caracterização do soro de leite de búfala os valores médios apresentaram umidade (89,94%), extrato seco total (10,06%), pH (6,29), densidade (1,029), acidez (10,070D), gordura (1,37%), proteínas (1,19%) e lactose (5,84%). Após a aplicação dos processos de microfiltração e pasteurização, observou-se uma redução da carga microbiana de 4,04 log UFC/mL do SA para 1,50 log UFC/mL no SP e para 0,70 log UFC/mL no SF. Quanto aos parâmetros físico-químicos avaliados foi constatado maiores perdas nutricionais nas amostras de SF quando comparado com o SP. Portanto, apesar do processo de microfiltração por membrana cerâmica ter sido mais eficiente que o processo de pasteurização em relação à redução de carga microbiana, ainda há necessidade de aperfeiçoamento, visando minimizar o processo de incrustação da mesma, o qual provocou retenção de nutrientes.