Memoria de Título para optar al título profesional de Ingeniero Agrónomo / En los últimos años se ha evidenciado un progresivo aumento del grado alcohólico de los vinos a nivel nacional e internacional, debido principalmente al cambio climático que ha favorecido la maduración de la uva más temprana, Además, por las últimas tendencias de elaboración de vinos con más estructura que ha generado que se retrase la fecha de cosecha, para conseguir una maduración fenólica más completa. Éste aumento generalizado de alcohol en los vinos ha generado inconvenientes para los consumidores que cada día se ha preocupado más por su salud y/o por moda busca preferentemente vinos con menores niveles de alcohol. Además, influyen imperativos legales relacionadas con las limitaciones de ingestas de alcohol. La industria enológica ha desarrollado diferentes tecnologías para la extracción del alcohol del vino evitando afectar sus características organolépticas. La osmosis inversa es una de las tecnologías más usadas a nivel nacional, la cual disminuye el alcohol por un sistema de membranas permeables y por presión. Sin embargo, existe la posibilidad en las bodegas que de forma fraudulenta agreguen agua con el fin de disminuir el grado alcohólico del vino. Frente a esta situación, el objetivo de éste estudio es comparar el efecto que produce la desalcoholización parcial de vinos por osmosis inversa y por diluciones con agua, sobre características físicas, químicas y sensoriales de los vino resultantes. El estudio se realizó durante el año 2013, se trabajó con un vino tinto del cv. Cabernet sauvignon de 15 % vol/vol de alcohol, el cual se disminuyó a 14,45, 13,5, 11,5, 10,5 y 9,5 % vol/vol de alcohol. Durante el mes de marzo se realizaron las desalcoholizaciones parciales por ambas tecnologías. Se conservaron las botellas durante dos meses (en un ambiente fresco y estable, en oscuridad, con temperaturas constantes entre 12 y 15 grados centígrados y en posición horizontal), con el fin de que se reestructurara el vino y finalmente se evaluaron los diferentes parámetros físicos, químicos y sensoriales de los vinos resultantes. Como conclusión se pudo observar que en aspectos físicos y químicos el método que menos afecta las características del vino inicial corresponde a la osmosis inversa, debido a que en sus distintos niveles de alcohol existe una baja variabilidad, existiendo diferencias significativas en sólo algunas características, en contraste a los tratamientos diluidos con agua, que poseen diferencias en casi todos los parámetros analizados. En el análisis sensorial de aceptabilidad, los vinos desalcoholizados por osmosis inversa tuvieron menores puntajes que los diluidos con agua en sus respectivas graduaciones alcohólicas estudiadas. Los hombres prefirieron los vinos con un mayor contenido de alcohol, mientras que las mujeres se inclinaron más por el vino con una pérdida media de alcohol. / In recent years there has been a progressive increase in the alcoholic strength of wine at national and international level, mainly due to climate change that has favored the ripening of the grapes and the latest trends winemaking more powerful structure which has led to delayed harvest date, to get a more complete phenolic ripening. This general increase alcohol level in wines has generated problems for consumers, because every day has been more concerned about their health and / or preferably looking fashionable wines with lower alcohol. In addition, influences of legal imperatives related to the limitations of intakes of alcohol are now stronger. The wine industry has developed different technologies for the removal of alcohol from the wine avoiding affecting the organoleptic characteristics. Reverse osmosis is one of the most widely used technologies at national level, which decreases alcohol by a permeable membrane system and pressure. However, the possibility exists in the wineries fraudulently add water to reduce the alcohol content of wine. Given this situation, the objective of this study is to compare the effect of the partial dealcoholisation wine by reverse osmosis and water dilutions on physical, chemical and sensory characteristics of the resulting wine. The study was carried out in 2013, using a red wine (Cabernet sauvignon) 15% vol/vol alcohol which decreased to 14.45, 13.5, 11.5, 10.5 and 9.5% vol/vol of alcohol. During the month of March at the end of the process of alcoholic fermentation diminutions were performed in both technologies, the bottles were stored for two months (in a cool and stable environment in darkness, constant temperatures between 12 and 15 degrees Celsius and horizontally) to restructure the wine and finally the different physical, chemical and sensory parameters were evaluated. In conclusion, it was observed that physical and chemical aspects of the method that least affects the characteristics of the initial wine corresponds to the reverse osmosis, as to their different levels of alcohol there is a low variability, with significant differences in just a few features, in contrast to diluted with water treatments, which have differences in nearly all parameters analyzed. In sensory analysis, reverse osmosis alcoholized wines had lower scores than diluted with water in their respective alcohol content studied. Men from the sensorial panel preferred wines with higher alcohol content, while women were more inclined for wine with an average loss of alcohol.

Thesis (Masters Diploma (Technology)--Cape Technikon, Cape Town,1993 / Various experimental and established membranes were tested on industrial effluents. Ultrafiltration, reverse osmosis and nanofiltration membranes were used in various applications. Research was done on aspects such as the cleaning of fouled membranes, production quality control and process development. Polyvinyl alcohol ultra-thin-film reverse osmosis membranes were manufactured for the desalination of brackish water to a potable standard. The membranes were manufactured in the tubular configuration. Experimental ultrafiltration, reverse osmosis and nanofiltration membranes were tested on cooling water blowdown on a laboratory-scale. On-site testing was done directly on the effluent at a later stage. A s!udy was also conducted to determine the effect of gel-polarization on membrane performance. The gel-layer model was used to predict the limiting flux of specific membranes. Membrane processes were also applied in the fractionation of wine-lees to provide usable by-products such as yeast cells and potassium bitartrate. Ultrafiltration membranes operated in diafiltration mode were used to "wash" the slurry at different solid concentrations. The bitartrate-rich permeate collected from ultrafiltration was then concentrated using reverse osmosis and nanofiltration to allow subsequent precipitation of the product.

Orientador: Roberto Herminio Moretti / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-06T15:51:38Z (GMT). No. of bitstreams: 1 Aguiar_AlessandraMaraLocatellide_M.pdf: 1450258 bytes, checksum: 8496d97a288559f534ce39db89383b61 (MD5) Previous issue date: 2006 / Resumo: O Brasil é um país com característica agrícola e o desenvolvimento dos setores agroindustriais é de grande importância sócio-econômica e que devem ser explorados a fim de evitar o desperdício de alimentos, agregar valor aos produtos agrícolas e aumentar a renda dos produtores. A transformação industrial, à experiência de regiões e países bem sucedidos, mostra que pelo menos a transformação primária das frutas deve ser pensada pelos produtores. Isto porque é um prolongamento das atividades agrícolas, que objetiva transformar produtos perecíveis em produtos estáveis. A bananicultura é uma atividade de importância econômica e social, sendo cultivada na maioria dos países tropicais. O Brasil é o terceiro maior produtor e representa cerca de 9,0% da produção mundial, com uma área de 495 mil ha, superado apenas pela Índia e pelo Equador. O presente trabalho estudou o processo de concentração osmótica em banana nanica (Musa cavendishi) através de planejamento experimental completo com 3 variáveis independentes (tempo, espessura e concentração de ácido cítrico), utilizando soluções de açúcar invertido, à pressão atmosférica e temperatura constante de 45°C. As variáveis dependentes para os 17 experimentos realizados foram: perda de peso, perda de umidade, incorporação de sólidos, variação de sólidos totais, variação de sólidos solúveis e a relação brix / acidez (ratio) que indica o equilíbrio das características sensoriais do produto. Para identificar a melhor relação foram selecionados 4 experimentos com diferentes ratio. Estas amostras de banana préconcentradas osmoticamente foram secas em estufa com circulação forçada de ar quente a 60°C até atingirem um teor de 65% de sólidos totais. Foi realizada uma análise sensorial (teste de preferência) com as 4 amostras selecionadas. Os resultados obtidos com os experimentos mostram uma perda de umidade entre 25,13 a 38,16% no processo de concentração osmótica e um produto com boas características organolépticas / Abstract: Brazil is a country with agricultural characteristics and thus the development of the agro-industrial sector is of great socio-economic importance and should be explored so as to avoid food wastage and increase the value of agricultural products and producer profit. Based on the experience of highly successful regions and countries, in industrial transformation, the primary transformation of fruits should be thought of by the producers, since this is really a prolongation of the agricultural activity, with the aim of transforming perishable products into stable ones. The culture of bananas is an economically and socially important activity, bananas being cultivated in the majority of tropical countries. Brazil is the third biggest producer, behind India and Ecuador, representing 9% of world production and occupying an area of 495 thousand hectares. This work studied the osmotic concentration of banana nanica (Musa cavendishi) using a complete experimental design with 3 independent variables (time, thickness and citric acid concentration), using invert sugar solutions, atmospheric pressure and a constant temperature of 45ºC. The variable dependents for the 17 experiments carried out were: weight loss, moisture loss, solids incorporation, variation in total solids, variation in soluble solids and the brix:acidity ratio, which indicates the equilibrium of the product sensory characteristics. Four experiments with different ratios were selected in order to identify the best ratio. These osmotically pre-concentrated banana samples were dried in a forced air incubator at 60ºC to a total solids content of 65%. A sensory preference analysis was carried out with the 4 samples selected. The results obtained showed moisture losses from 25.13 to 38.16% in the osmotic concentration process and a product with good organoleptic characteristics / Mestrado / Mestre em Tecnologia de Alimentos

Magíster en Ciencias de la Ingeniería, Mención Recursos y Medio Ambiente Hídrico. Ingeniero Civil / El objetivo principal de este trabajo fue realizar un estudio experimental para evaluar el rendimiento de nuevas membranas de osmosis inversa modificadas con nanopartículas de cobre (CuO, CuCl2, Cu(s)) y titania (TiO2) en la desalinización de agua. Se diseñó e implementó una planta piloto capaz de realizar una filtración de flujo cruzado para determinar el caudal de agua permeada a través de un área de membrana, definido como flux, y el porcentaje de rechazo de estas. Para ello se sintetizaron membranas Thin Film Composite (TFC) a las cuales se les adicionaron las nanopartículas durante la polimerización interfacial, a diferencia de otros métodos de modificación por inmersión. Estas membranas fueron caracterizadas mediante microscopía de fuerza atómica (AFM) para determinar la rugosidad, espectroscopía de energía dispersa por rayos X (EDX) para determinar la presencia de las nanopartículas en la membrana, microscopía electrónica de barrido (SEM) para determinar la estructura de la membrana y ángulo de contacto para determinar la hidrofilicidad superficial. Además, se realizaron ensayos biológicos para determinar la capacidad de anti-adhesión y efecto bactericida para la bacteria E.Coli. De estos experimentos se obtuvo que todas las membranas modificadas mejoraron su efecto anti-adhesión, obteniendo resultados hasta un 99 % mejores. En cuanto al efecto biocida, las membranas modificadas con cobre presentaron una mejora significativa, logrando hasta un 80 % más de bacterias muertas que una membrana sin modificar. Se llevaron a cabo experimentos en el Laboratorio de Hidráulica Francisco J. Domínguez de la Universidad de Chile a una presión de 300 psi en todo el sistema, para determinar el rendimiento de una membrana comercial y las membranas sintetizadas en laboratorio, al desalinizar una solución salobre de 1000 ppm de concentración de NaCl. Se obtuvo que las membranas modificadas con CuO y CuCl2 al 1% mejoran el flux permeado con respecto a una membrana sin modificar. Adicionalmente, se obtuvo que la modificación con partículas de CuO al 1 % presentó una mejora del flux con respecto a la membrana comercial. Además, se obtuvo que todas las modificaciones mantuvieron el porcentaje de rechazo de sales por sobre un 94 %. Se realizó un experimento para determinar una posible polarización de la concentración (acumulación de especies iónicas en la membrana), donde se obtuvo que las membranas sintetizadas, a diferencia de la membrana comercial, estaban siendo afectadas por este fenómeno, aumentando la resistencia al paso del agua.

No description available.

abstract: Managing water resources has become one of the most pressing concerns of scientists both in academia and industry. The reverse osmosis (RO) water treatment process is a well-researched technology among the pressure driven processes to produce potable water. RO is an energy intensive process and often RO membranes are susceptible to fouling and scaling that drives up operational cost and hinder the efficiency. To increase the performance of RO membranes the feed water is pretreated to remove pollutants before desalination. This work aims to fabricate pretreatment membranes to prevent the effects of fouling and scaling by introducing hydrophilic character to membrane. This work explores electrospinning, a cost-effective and scalable technique, to blend two polymers into a nonwoven membrane comprised of fibers ~100 nm - 10 µm in diameter. A rotary drum collector holding the mat was used to simultaneously collect the electrospun hydrophobic poly(vinyl chloride) (PVC) and hydrophilic poly(vinyl alcohol) (PVA) fibers from two separate solutions. The hydrophilicity of the resulting membrane was tuned by controlling the relative deposition rate of PVA onto the co-spun mat. Fiber diameter and morphologies were characterized by scanning electron microscopy, and Fourier-transform infrared spectroscopy and Confocal fluorescence microscopy further confirmed the presence of both polymers. Moreover, a rigorous analysis to map the PVA/PVC concentration was established to accurately report the relative concentrations of the two polymers on the co-spun mat. After electrospinning, the PVA in the co-spun mats were cross-linked with poly(ethylene glycol) diacid to impart mechanical strength and tune the porosity. EDS analysis revealed inconsistencies in the mass deposition of both polymers suggesting an improvement in the current experimental design to establish a meaningful relationship between PVA concentration and hydrophilicity. However, tensile test revealed that co-spun mats with high mass flow ratios of PVA possessed high mechanical strength showing a significant improvement in the Young’s Modulus. Furthermore, the co-spun mats were challenged with filtration experiments expecting a positive correlation of flux with PVA concentration. But it was found that with increased concentration, crosslinked PVA constricted PVC fibers minimizing the pores causing a lower flux and a dense membrane structure suitable for filtration. / Dissertation/Thesis / Masters Thesis Chemical Engineering 2020

This thesis deals with water reclamation and water reuse in the South African water supply context. The overall objective of the study is to assess the potential role and feasibility of reverse osmosis as a water reclamation process. In order to achieve this objective a number of separate desk, laboratory and pilot plant studies were conducted. It was concluded from the first desk study that a significant potential role exists for reverse osmosis in the South African water economy, mainly for the treatment of industrial effluents and, in the longer term, for the reclamation of water from sewage effluents and for the treatment of effluents and recycled water in indirect water reuse situations. A cost analysis showed that reverse osmosis could become economically viable in some water reuse situations in the near future provided that a productive membrane life of about three years can be achieved and that membrane fluxes can be maintained at design rates. These findings indicated the need for a pilot plant study to determine the effects of pretreatment and membrane cleaning on flux levels and rejection. A 50 m³/d pilot plant was designed and operated for a period of about six months from which it was concluded that acceptable flux levels can be maintained in tubular reverse osmosis plants treating well-oxidized activated sludge effluent with and without extensive pretreatment, provided both chemical and physical cleaning methods are employed. The desk study on the rejection of contaminants by reverse osmosis membranes indicated the need for a simple model that can be used to predict the removal of organic compounds of interest in water reclamation applications. It was concluded from a fundamental laboratory study, which included the evaluation of existing membrane models against laboratory data, that the solvophobic theory can be adapted in a simplified form to predict the transport of dissolved organic compounds in relatively non-polar reverse osmosis membranes. Based on reverse osmosis, diffusion, sorption and desorption data a mechanism is, furthermore, proposed for the transport of phenol in different membranes.

Water scarcity is a serious global issue, due to the increasing population and developing economy, and membrane technology is an essential way to address this problem. Forward osmosis (FO) is an emerging membrane process, due to its low energy consumption (not considering the draw solute regeneration). A bottleneck to advance this technology is the design of the support layer for FO membranes to minimize the internal concentration polarization. In this dissertation, we focus on the structural study and modification of the support layer for FO membranes. Firstly, we digitally reconstruct different membrane morphologies in 3D and propose a method for predicting performance in ultrafiltration operations. Membranes with analogous morphologies are later used as substrate for FO membranes. Secondly, we experimentally apply substrates with different potentially suitable morphologies as an FO support layer. We investigate their FO performance after generating a selective polyamide layer on the top, by interfacial polymerization. Among the different substrates we include standard asymmetric porous membranes prepared from homopolymers, such as polysulfone. Additionally block copolymer membrane and Anodisc alumina membrane are chosen based on their exceptional structures, with cylindrical pores at least in part. 3D digitally reconstructed porous substrates, analogous to those investigated for ultrafiltration, are then used to model the performance in FO operation. Finally, we analyze the effect of intermediate layers between the porous substrate and the interfacial polymerized layer. We investigate two materials including chitosan and hydrogel. The main results are the following. Pore-scale modeling for digital membrane generation effectively predicts the velocity profile in different layers of the membrane and the performance in UF experiments. Flow simulations confirm the advantage of finger-like substrates over sponge-like ones, when high water permeance is sought. Cylindrical pores are advantageous for mass transfer. Block copolymer substrates have cylindrical pores in the top layer and very regular pore pattern at the surface. The Anodisc alumina membrane has cylindrical pores from top to bottom. Both substrates were experimentally tested for FO application successfully. A Darcy permeability higher than 1E-20 m2 for the intermediate layer would be necessary in order to facilitate the water flow.

Memoria para optar al título de Ingeniero Civil en Biotecnología / La incrustación (fouling) biológica es una de las mayores causas de daño en membranas para sistemas de purificación de agua por osmosis reversa (OR). La modificación de las membranas mediante la adición de nanopartículas (NPs) metálicas u óxidos, con características antimicrobianas, han demostrado mejorar la resistencia de la membrana al biofouling. Sin embargo, el mecanismo tóxico varía dependiendo del tipo de nanopartícula incorporada. En el caso de las modificaciones con cobre, los mecanismos de acción de las nanopartículas de cobre y su incidencia cuando se encuentran en la membrana modificada aún no son claros. En el presente trabajo se estudiaron los parámetros y mecanismos por los cuales las NPs inducen efectos nocivos, esto mediante un estudio de las vías tóxicas para 3 tipos de membranas con distintas modificaciones con cobre: nanopartículas de cobre elemental (Cu-NPs), nanopartículas de óxido de cobre (CuO-NPs) y un oligómero de cobre formado a partir de sal de cobre (Cu-MPD), todo esto con el objetivo de caracterizar y estudiar los mecanismos biocidas del cobre en estas membranas modificadas, junto a la generación de un modelo que describa la capacidad biocida de las nanopartículas en membranas de osmosis reversa. A partir de la bibliografía revisada se encontró que el efecto tóxico más preponderante de las NPS en membrana corresponde a la disolución de las NPs con liberación de iones, los cuales inducen toxicidad en células al superar una concentración dada. Todos estos efectos están sujetos a características de la nanopartícula como su tipo, tamaño y forma, y también a las condiciones de medio. Este efecto fue estudiado mediante un seguimiento de la cinética de disolución, tanto en suspensión como en membrana. Además, se realizaron pruebas con las membranas en presencia de un cultivo de E. coli, en donde se monitoreó la viabilidad de las bacterias mediante conteo de colonias viables (CFU) y se obtuvieron indicadores para cuantificar el efecto tóxico del cobre. Estos no mostraron diferencias apreciables entre los cobres estudiados, los cuales con capaces de mantener un alto nivel de inhibición (mayor al 90%), incluso luego de alcanzada la fase exponencial de crecimiento del microorganismo. Se obtuvieron cinéticas de primer orden de disolución que varían según el tipo de cobre utilizado. Debido a las diferencias observadas en las cinéticas de disolución, se plantearon 2 modelos para describir la liberación de iones de cobre desde las membranas modificadas. Los modelos obtuvieron una buena correlación con los datos experimentales. El análisis de estos modelos permitió identificar que la carga efectiva de cobre en membrana es uno de los fenómenos más relevantes para caracterizar la eficiencia biocida de las mismas, dado que define la tasa de liberación de iones y el tiempo de vida del cobre en la membrana. Finalmente, a partir del modelo anti-biofouling propuesto, se obtuvo que las membranas de Cu-MPD presentan una ventaja frente a las NPs, dado que alcanzan un poder biocida similar con menor carga de cobre, con un efecto más perdurable en el tiempo. La metodología utilizada puede ser implementada en otros modelos que incluyan el uso de nanopartículas.

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第19474号 / 理博第4134号 / 新制||理||1595(附属図書館) / 32510 / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)准教授 荒木 武昭, 教授 佐々 真一, 教授 山本 潤 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM