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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
211

Solid-State NMR Studies of Polymeric and Biomembranes

Spano, Justin 17 June 2011 (has links)
The objective of this dissertation is to demonstrate different applications of ssNMR, with particular emphasis on uses in polymeric and biosciences. First, dynamics investigations on two polymers will be discussed: (1) disulfonated poly(arylene ether sulfone)s /poly(ethylene glycol) blends (BPS-20_PEG), which are under development as chlorine-resistant reverse osmosis (RO) membrane alternatives to aromatic polyamide (PA) technology, and (2) poly(arylene ether sulfone)s modified with 1,4-cyclohexyl ring units to improve processability. Simple cross-polarization magic-angle-spinning (CPMAS) experiments compared the chlorine tolerance of BPS-20_PEG and PA. Techniques capable of detecting motional geometries and rates on timescales from nanoseconds to seconds, including relaxation time measurements, were applied. Correlations were established between relaxation time and water permeability for the RO membranes, and between relaxation time and polydispersity in the 1,4- cyclohexyl ring modified polymer. Next, 31P and 2H static ssNMR experiments evidencing the formation of toroidal pores and thinned bilayers in oriented zwitterionic and anionic phospholipid bilayers, (biomembrane mimetic systems), by the antimicrobial peptides (AMPs) magainin-2 and aurein-3.3, will be mentioned. The toroidal pore geometries induced by magainin-2 were different than those produced by aurien-3.3. The most prominent features were observed in 2H spectra, implying greater interaction of the peptides with hydrophobic lipid acyl chains. Following this, a new two-dimensional homonuclear dipolar recoupling MAS experiment, capable of correlating long range 13C-13C spin pairs in a uniformly/ extensively 13C-labeled biomolecule, will be introduced. This technique was demonstrated on 13C-labeled versions of Glutamine and Glycine-Alanine-Leucine. Experiments involving the recoupling of all 13C-13C spin pairs, and experiments with selective recoupling using Gaussian or cosine-modulated Gaussian pulses, were demonstrated. Finally, work using static 1H- 13C CP ssNMR to selectively detect interfacial water around hydrophobic C60 will be recounted. This project exploited the distance limitation of CP, and 1H spin-lattice relaxation times, to separate the influence of bulk and interfacial water on the spectra. Results indicated that the tumbling of interfacial water is slowed by a factor of 105 compared to bulk water, providing it with a solid-like character, and allowing the hydration shell to be stable at temperatures above the freezing point of water. / Ph. D.
212

Electroding Methods for in situ Reverse Osmosis Sensors

Detrich, Kahlil 19 March 2010 (has links)
The purpose of this work is to develop and evaluate electroding methods for a reverse osmosis (RO) membrane that results in an in situ sensor able to detect RO membrane protein fouling. Four electroding techniques were explored: i) gold exchange-reduction, ii) encapsulated carbon grease, iii) "direct assembly process" (DAP), and iv) platinized polymer graft. The novel platinized polymer graft method involves chemically modifying the RO membrane surface to facilitate platinization based on the hypothesis that deposition of foulant on the platinized surface will affect platinum/foulant/solution interfacial regions, thus sensor impedance. Platinized polymer graft sensors were shown to be sensitive to protein fouling. Electrodes were characterized by their electrical properties, SEM and XPS. Assembled sensors were evaluated for sensitivity to electrolyte concentration and protein fouling. Micrographs showed coating layers and pre-soak solution influence gold exchange-reduction electrode formation. High surface resistance makes gold exchange-reduction an unsuitable method. Concentration sensitivity experiments showed carbon grease and DAP electroding methods produce unusable sensors. Carbon grease sensors have time-dependent impedance response due to electrolyte diffusion within the micro-porous polysulfone support. DAP electroded sensors proved quite fragile upon hydration; their impedance response is transient and lacks predictable trends with changes in concentration. A parametric study of the platinized polymer graft method shows amount of grafted monomer correlates to grafting time, and deposited platinum is a function of exchange-reduction repetitions and amount of grafted monomer. Platinized polymer graft sensors were fouled in both dead-end and cross-flow RO systems, and their impedance trends, while varying between sensors, indicate protein-fouling sensitivity. / Master of Science
213

"Balanço de massa de um sistema de ultrafiltração e osmose reversa para desssalinização de água salobra"

Rodrigues, Ana Carolina Martins 12 April 2018 (has links)
Submitted by Eunice Novais (enovais@uepg.br) on 2018-06-26T19:10:46Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Ana Carolina M. Rodrigues.pdf: 2130324 bytes, checksum: 0340ff571493224c3f33ecd693bb1e77 (MD5) / Made available in DSpace on 2018-06-26T19:10:46Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Ana Carolina M. Rodrigues.pdf: 2130324 bytes, checksum: 0340ff571493224c3f33ecd693bb1e77 (MD5) Previous issue date: 2018-04-12 / Fundação Araucária de Apoio ao Desenvolvimento Científico e Tecnológico do Paraná / A má distribuição de água doce no mundo, o crescimento populacional acentuado, as mudanças climáticas e as consequências das ações antropológicas traz a necessidade da busca de fontes alternativas para suprir a demanda de água aos seres humanos, animais e plantas. A abundância de água salgada ou salobra é muitas vezes, a única fonte de água disponível para sobrevivência de algumas comunidades no planeta, isso tem impulsionado o uso de técnicas de dessalinização. Com o objetivo de estudar alternativas para adaptações climáticas, antecipar tendências e problemas hídricos futuros foi implantado um sistema de dessalinização de água salobra, em escala piloto, nas dependências da Estação de Tratamento de Água (ETA) da Sanepar, em Praia de Leste, no município de Pontal do Paraná no litoral do estado. O sistema piloto foi provido de ultrafiltração (UF) como pré-tratamento seguido de abrandamento e da dessalinização por osmose reversa (OR). Com capacidade para produzir 1 m3.h-1 de água tratada. A água salobra foi padronizada nas concentrações de 1000 ± 50 mg.L-1 e 1500 ± 20 mg.L-1 de sólidos dissolvidos totais (SDT), por meio da mistura da água do mar e da água bruta do Rio das Pombas, manancial que abastece o balneário. Avaliou-se o sistema global a partir de dados de produção e consumo de água, balanço de massa e das taxas de recuperação para configurações diferentes do sistema de OR. Para isso, foram realizados quatro experimentos, variando a configuração de abertura do registro do concentrado da OR: o primeiro com abertura de 72,71% de concentrado (A); o segundo 59,20 % (B); o terceiro 39,70% (C), estes com 1500 ± 20 mg.L-1 de SDT; o quarto experimento foi realizado para 1000 ± 50 mg.L-1 de SDT com abertura de 32,90% de concentrado (D). Aproximadamente 15% do volume de alimentação era utilizado na limpeza hidráulica das membranas da UF e da OR. Quanto maiores as vazões do concentrado da OR, maior a vazão de alimentação, e consequentemente, menor a taxa de recuperação e pressão osmótica. A maior taxa de recuperação obtida foi de 69,13% para o experimento D, sendo considerada a configuração mais otimizada. / With the unequal distribution of fresh water in the world, strong population growth, climate change and the consequences of anthropological actions it is necessary to look for alternative sources to supply the water demand for human beings, animals and plants. Salt water or brackish water has been the only source of water available for survival in some communities on the planet. This issue has driven the use of desalination techniques. With the objective of studying alternatives for climate adaptation, anticipating of trends and problems and water problems, a brackish water desalination system in pilot scale was implemented on the premises of the Water Treatment Plant Station, in Praia de Leste, in the Pontal do Paraná City, coast of the State. The pilot system was provided with ultrafiltration (UF) as a pretreatment followed by softening and reverse osmosis (RO), with the capacity to produce 1m3.h-1 of permeate. Brackish water was produced at concentrations of 1,000 ± 50 mg.L-1 and 1,500 ± 20 mg.L-1 of total dissolved solids (TDS), by mixing sea water and fresh water from the Pombas River, which supplies the town. The global system was evaluated from production and water consumption data, mass balance and recovery rates for different configurations of the reverse osmosis system. For this, four experiments were performed, varying the configuration of the valve which controls the flow of the brine: the first one with 72.71% (A); the second with 59.20%(B); the third with 39.70% (C), these with 1,500 ± 20 mg.L-1 of TDS; the fourth experiment was also performed for 1,000 ± 50 mg.L-1 of TDS with 32.90% of the brine (D). About 15% of volume of water produced was used in the hydraulic cleaning of the UF and RO membranes. When the flow rates of the concentrate were higher, the feed rates were also higher and consequently, the recovery rates and osmotic pressure were lower. The highest recovery rate was 69.13% for the experiment D, being considered the most optimized configuration.
214

Filtrato dinamika Jėrubaičių sąvartyne / Landfill leachate dynamic in Jėrubaičiai

Simaitis, Donatas 16 June 2010 (has links)
Vienu iš pagrindiniu geologinės aplinkos teršėju yra laikomi sąvartynai. Todėl daugelyje šalių jie yra inventorizuojami ir tiriami, prognozuojamas jų poveikis gamtinei aplinkai. Lietuvai sąvartynų poveikio aplinkai problema taip pat labai aktuali. Todėl imtasi konkrečių priemonių informacijos apie sąvartynus kaupimui ir jų taršos mąsto įvertinimo. Tuo tikslu buvo atliekama ir iki šiol tebevykdoma sąvartynų inventorizacija. Kai kuriuose sąvartynuose buvo vykdomi įvairaus detalumo geologiniai-hidrogeologiniai tyrimai. Šiame darbe analizuojama Jerubaičių sąvartyno filtrato dinamika. Pateikiama sąvartyne susikaupusio filtrato judėjimo schema. Bei jo valymas atvirkštinės osmozės būdu. Tiriamas filtrato kiekio kitimas keičiantis meteorologinėm sąlygom, analizuojamas laikotarpis nuo 2008.05.15 iki 2008.12.31. Tiriamas laikotarpis, nuo gegužės 15 iki sausio 1, apima visus metų laikus bei atspindi tipines Lietuvos meteorologinės sąlygos. Darbe tiriama filtrato susidarymo priklausomybė sąvartyne nuo atvežamų šiukšlių kiekio ir meteorologinių sąlygų. Duomenys pateikiami grafiškai juos apdorojus, duomenų statistiniam apdorojimui panaudota programa STATISTICA. / Landfill is considered as one of the main geo-environmental polluters. Therefore, in most countries they are inventoried, analyzed and forecast their impact for the natural environment. Lithuania landfill’s environmental problem is also relevant. Consequently, there are taken appropriate actions about landfills and their accumulation of pollution assessment. This was done and it is still ongoing landfill inventory. In some landfills there were carried out a wide range of detail geological-hydrogeological researches. This document analyzes Jėrubaičiai landfill leachate dynamics. There is available landfill leachate accumulated movement scheme and its cleaning by reverse osmosis method. This analysis shows leachate flow dynamics in different meteorological conditions. Research period was from 2008.05.15 to 2008.12.31. Selected research period is covering all seasons and represents Lithuanian meteorological conditions. In this document explored formation of leachate dependency from incoming garbage amount and weather conditions. Research data are represented graphically; program STATISTICA was used for statistical data processing.
215

Optimal scheduling, design, operation and control of reverse osmosis desalination : prediction of RO membrane performance under different design and operating conditions, synthesis of RO networks using MINLP optimization framework involving fouling, boron removal, variable seawater temperature and variable fresh water demand

Sassi, Kamal M. January 2012 (has links)
An accurate model for RO process has significant importance in the simulation and optimization proposes. A steady state model of RO process is developed based on solution diffusion theory to describe the permeation through membrane and thin film approach is used to describe the concentration polarization. The model is validated against the operation data reported in the literature. For the sake of clear understanding of the interaction of feed temperature and salinity on the design and operation of RO based desalination systems, simultaneous optimization of design and operation of RO network is investigated based on two-stage RO superstructure via MINLP approach. Different cases with several feed concentrations and seasonal variation of seawater temperature are presented. Also, the possibility of flexible scheduling in terms of the number of membrane modules required in operation in high and low temperature seasons is investigated A simultaneous modelling and optimization method for RO system including boron removal is then presented. A superstructure of the RO network is developed based on double pass RO network (two-stage seawater pass and one-stage brackish water pass). The MINLP problem based on the superstructure is used to find out an optimal RO network which will minimize the total annualized cost while fulfilling a given boron content limit. The effect of pH on boron rejection is investigated at deferent seawater temperatures. The optimal operation policy of RO system is then studied in this work considering variations in freshwater demand and with changing seawater temperature throughout the day. A storage tank is added to the RO layout to provide additional operational flexibility and to ensure the availability of freshwater at all times. Two optimization problems are solved incorporating two seawater temperature profiles, representing summer and winter seasons. The possibility of flexible scheduling of cleaning and maintenance of membrane modules is investigated. Then, the optimal design and operation of RO process is studied in the presence of membrane fouling and including several operational variations such as variable seawater temperature. The cleaning schedule of single stage RO process is formulated as MINLP problem using spiral wound modules. NNs based correlation has been developed based on the actual fouling data which can be used for estimating the permeability decline factors. The correlation based on actual data to predict the annual seawater temperature profile is also incorporated in the model. The proposed optimization procedure identified simultaneously the optimal maintenance schedule of RO network including its design parameters and operating policy. The steady state model of RO process is used to study the sensitivity of different operating and design parameters on the plant performance. A non-linear optimization problem is formulated to minimize specific energy consumption at fixed product flow rate and quality while optimizing the design and operating parameters. Then the MINLP formulation is used to find the optimal designs of RO layout for brackish water desalination. A variable fouling profile along the membrane stages is introduced to see how the network design and operation of the RO system are to be adjusted Finally, a preliminary control strategy for RO process is developed based on PID control algorithm and a first order transfer function (presented in the Appendix).
216

Predicting removal efficiency of reverse osmosis membranes with respect to emerging substances of concern using a discriminant function analysis

Unknown Date (has links)
This paper presents the results of the spike tests performed in the alternative water supply pilot testing program for the City of Pembroke Pines. It establishes the effectiveness of a protocol that can be used to gain further insight on the rejection capacities of RO membranes. An in-depth study of the molecular descriptors affecting rejection by RO membranes is presented and used in the development of a discriminant function analysis. This analysis proved to be an effective way to predict the passage of Emerging Substances of Concern (ESOCs) through RO membrane. Further, a principal component (PC) analysis was performed to determine which factors accounted the largest variation in RO permeability. Additionally, this paper defines the groundwork for a discriminant analysis model that, if further developed, could serve as an important tool to predict the rejection capabilities of RO treatment when handling with ESOCs. / by Fernando J. Pleitez Herrera. / Thesis (M.S.C.S.)--Florida Atlantic University, 2012. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.
217

Técnicas analíticas para autópsia de membranas de osmose reversa. / Analytical techniques for the autopsy of reverse osmosis membranes.

Costa, Thiago Ranzani da 17 November 2011 (has links)
Sistemas de membranas filtrantes, principalmente os de osmose reversa, estão sendo cada vez mais utilizados em diversos seguimentos de empresas (farmacêutica, tratamento de água, alimentícia e química), devido à diminuição do preço dos elementos filtrantes e da alta qualidade do produto obtido. Apesar do preço dos elementos de osmose reversa terem caído nos últimos tempos, a substituição destes continua sendo o fator mais dispendioso de um sistema de osmose reversa. A autópsia de membranas é uma técnica utilizada para investigar a causa que levou à colmatação de um elemento, contribuindo no melhoramento do pré-tratamento da água de alimentação e consequentemente aumentando a vida útil dos elementos. O presente trabalho teve como objetivo incrementar a técnica de autópsia de membranas de osmose reversa através da análise da volatilização dos principais compostos inorgânicos presentes nestas membranas, modificação na metodologia de quantificação de açúcares e proteínas, comparação de diferentes técnicas de remoção do material depositado sobre as membranas e análise da distribuição de biofilmes sobre elementos colmatados de osmose reversa. A análise dos resultados mostrou que dentre os inorgânicos, ocorreu volatilização completa do cloreto de amônio e pequena variação no composto cloreto férrico; a quantificação de proteínas e açúcares, através da fortificação das amostras, apresentou valores diferentes quando comparados com os valores obtidos diretamente da curva padrão, devido à diferença de inclinação entre as retas de fortificação e padrão; os resultados também mostraram que a trituração foi mais eficiente na remoção do material aderido quando comparado com a raspagem e a sonicação e a distribuição de biofilmes se mostrou uniforme nos dois elementos analisados. / Filter membrane systems, especially reverse osmosis, are being increasingly used in various business segments (pharmaceutical, water treatment, food and chemical) due to decrease in the price of the filter elements and high quality product. Although the price of reverse osmosis elements have fallen in recent times, the replacement of the part remains more expensive a reverse osmosis system. The autopsy of membranes is a technique used to investigate the cause that led to clogging of one factor contributing to the improvement of pre-treatment of water feeding and consequently increasing the life of the elements. This study aimed to improve the technique of autopsy reverse osmosis membranes by examining the volatilization of major inorganic compounds present in these membranes, modification the methodology for quantification of sugars and proteins, comparison of different techniques for removal of material deposited on the membranes and distribution analysis of biofilms on elements obscured reverse osmosis. The results showed that among the Inorganic volatilization was full of ammonium chloride and small variation in the compound ferric chloride, the quantification of proteins and sugars, by fortifying the samples showed different values when compared with values obtained directly the standard curve due to the difference in slope between the lines of and fortification standard, the results also showed that the blending was more efficient in removing adhered material when compared with the scraping and sonication and distribution of biofilms showed uniform the two elements analyzed.
218

Avaliação de eficácia da sanitização de um sistema de purificação de água. Esterilização de artigos médicos, dissipação residual do óxido de etileno e uso da proteína verde fluorescente (GFP) como inidicador de controle do processo / Evaluation of effectiveness of the sanitization of a water purification system. Sterilization of medical devices, residual dissipation of ethylene oxide and the use of green fluorescent protein (GFP) as an indicator of process control

Fabio Nunes Dias 22 August 2007 (has links)
A água exerce papel fundamental nas diferentes fases do processo de fabricação de artigos para saúde (médico-hospitalares, farmacêuticos, e clínicos), exigindo elevado grau de pureza, que certifique a sua inocuidade. Portanto, se faz necessário maior controle dos sistemas de purificação de água e suas etapas de tratamento, onde a formação de biofilmes pode contaminar os artigos para saúde e, consequentemente, causar injúria a pacientes submetidos à aplicação dos mesmos. Embora os artigos médicos sejam esterilizados por óxido de etileno (ETO), seu processo de manufatura deve prever o mínimo acréscimo possível de contaminantes. Considerando que a água purificada e a esterilização dos artigos para saúde são fatores determinantes para o sucesso de sua aplicação, este trabalho foi dividido em duas partes distintas. A primeira parte aborda o controle das etapas de purificação da água, que é destinada à lavagem de componentes termoplásticos, que são utilizados na fabricação de artigos para saúde. Os níveis máximos de carga microbiana (expressos em ciclos de log10 UFC/100mL) encontrados ao longo do sistema de purificação de água foram: 3,48 log10 na água de entrada; 3,57 log10 nos filtros multimeios; 3,75 log10 nos abrandadores; 4,97 log10 no filtro de carvão ativado; 2,53 log10 na osmose reversa; 2,70 log10 no tanque de estocagem e distribuição; 2,56 log10 na lâmpada ultravioleta; 2,53 log10 nos filtros 0,05 µm; 1,98 log10 nos pontos de uso. Flavimonas oryzihabitans e Micrococcus luteus foram as bactérias Gram-negativa e Grampositiva, respectivamente, isoladas e identificadas com maior freqüência na água, em diferentes estágios do sistema, inclusive após a passagem dessa através das membranas de osmose reversa. A segunda parte do estudo teve como objetivo determinar o tempo de aeração necessário para que os oxigenadores de sangue e conjuntos de tubos de PVC, após esterilização por ETO, permaneçam em aeração, para dissipação dos resíduos de ETO. Avaliou-se também a potencialidade da proteína verde fluorescente (GFP) como biossensor no processo de esterilização. O processo de esterilização destes artigos médicos foi monitorado com indicadores biológicos Bacillus atrophaeus, proteína verde fluorescente (GFP) e controles de temperatura, pressão e umidade em ciclos de 2 h (ciclo curto), 4 h (meio ciclo) e 8 h (ciclo longo). As curvas de dissipação, determinadas por cromatografia gasosa, confirmaram níveis residuais menores que 25 ppm para ETO e etileno cloridrina (EC); e inferiores a 250 ppm para etileno glicol (EG), ao final do processo de esterilização para os oxigenadores; e, após 221 horas de aeração, para os conjuntos de tubos de PVC. Nos ciclos de esterilização, as reduções na intensidade de fluorescência da GFP ocorreram em função do tempo de exposição ao ETO; enquanto germinação de esporos e/ou crescimento de B. atrophaeus não foi observado. / The water exerts important paper in different phases of critical items manufacture in the health care units, pharmaceutical industries, hospitals and clinics, becoming necessary a rigorous control of the water purification systems, storage and distribution, in order to prevent biofilms formation and cross-contamination between devices and patients, who are submitted to critical articles and parenteral solution application. The sterilization of critical devices by ethylene oxide (ETO) should predict minimum addition of possible contaminants and residues. Considering that the purified water and the sterilization are crucial factors for medical devices, this work was divided in two parts. The first part evaluated continuously the stages of the system for the purification of the water, which purity level is critical and determines the quality of the washing of thermoplastic components used in the manufacture of critical items. The maximum levels of heterotrophic load (log10 UFC/100mL) found throughout the water purification system were: 3.48 log10 in the water inlet; 3.57 log10 in the multimedium filters; 3.75 log10 in the softeners; 4.97 log10 in the activated carbon filter; 2.53 log10 in the reverse osmosis; 2.70 log10 in the tank of storage and distribution; 2.56 log10 in the UV lamp; 2.53 log10 in the 0.05µm filters; 1.98 log10 in the consumption points. Flavimonas oryzihabitans and Micrococcus luteus were the main Gram-negative and Grampositive bacteria, respectively found in the purified water after reverse osmosis. The second part of this study had as objective the determination of the needed aeration time for blood oxygenators and sets of PVC tubing must be kept in aeration room for dissipation of ETO residues; and also evaluated the possibility of GFP as biosensor. ETO is used as in a mixture (10% ETO and 90% CO2). Residual levels of ETO and its derivatives, ethylene chloridrin (ECH) and ethylene glycol (EG), which remain in these devices, must be controlled to prevent serious injuries to the patients. The sterilization process of the oxygenators and sets of PVC tubing was monitored with Bacillus atrophaeus and fluorescent green protein (GFP). The temperature, pressure and humidity were controlled in the sterilization cycles of 2 h (short cycle), 4 h (half cycle) and 8 h (long cycle). The dissipation curves of the residues were determined by gaseous chromatography and the residual concentrations were lower than 25 ppm of ETO and ECH and lower than 250 ppm of EG immediately after the sterilization processes for oxygenators and after 221 hours of aeration for the sets of PVC tubing. Reductions in the fluorescence intensity of GFP were observed as a function of the exposition time to the ETO. No growth of B. atrophaeus spores was observed after cycles.
219

Avaliação de um sistema de dessalinização de água salobra em escala piloto

Bovaroti , Tatiane 12 April 2018 (has links)
Submitted by Eunice Novais (enovais@uepg.br) on 2018-07-31T12:05:01Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Tatiane Bovaroti.pdf: 1677408 bytes, checksum: 74791391260b47b48abc127d7af4af68 (MD5) / Made available in DSpace on 2018-07-31T12:05:01Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Tatiane Bovaroti.pdf: 1677408 bytes, checksum: 74791391260b47b48abc127d7af4af68 (MD5) Previous issue date: 2018-04-12 / Preocupados com a intrusão de água do mar, escassez e má qualidade das reservas de água doce no mundo, diversos países têm estudado e proposto sistemas de alta tecnologia que sejam viáveis para a dessalinização de água salobra ou salina. Este trabalho teve como objetivo principal avaliar a eficiência de um sistema de ultrafiltração (UF) como pré-tratamento, seguido de abrandamento e osmose reversa (OR) para a dessalinização de água salobra em escala piloto, instalado no balneário de Praia de Leste, litoral do estado do Paraná. Para a obtenção da água salobra foi realizada a mistura da água do rio das Pombas com a água do mar até a concentração de 1500 (± 100) mg. L-1 de sólidos dissolvidos totais (SDT). O sistema foi projetado para a produção de 1 m3.h-1 de água doce (permeado da OR) e operou por aproximadamente 3h por dia durante vinte dias não consecutivos. Analisaram-se amostras de nove pontos de coleta durante a primeira (A), segunda (B) e terceira (C) hora de operação. Para a avaliação da qualidade da água os parâmetros analisados foram: SDT, condutividade elétrica, pH, temperatura, cor aparente, turbidez, alcalinidade total, dureza total, cálcio, cloreto, sulfato, coliformes totais e E.coli. Para avaliação da eficiência do sistema, calculou-se a taxa de recuperação e o fluxo de filtração, bem como a leitura de outros parâmetros operacionais como a pressão osmótica. O sistema de UF apresentou remoção média de 95,1% de turbidez e de 98,6% de cor aparente na água salobra. Constatou-se ausência de coliformes totais e E.coli no permeado. Houve variação quanto à remoção de dureza total e cálcio pelo abrandador devido ao tempo de regeneração do sistema. O sistema de OR obteve remoção média de 99,4% de SDT e a maior taxa de recuperação global (UF e OR) foi de 57,4%. / Concerned about the intrusion of sea water, scarcity and poor quality of freshwater reserves in the world, several countries have studied and proposed high technology systems that are feasible for the desalination of brackish or saline water. The main objective of this work was to evaluate the efficiency of an ultrafiltration (UF) system as a pretreatment, followed by slowing and reverse osmosis (RO) for pilot scale saline water desalination, installed in Praia de Leste – coast of the state of Paraná. To obtain the brackish water, the water of the Pombas River was mixed with sea water up to the concentration of 1500 (± 100) mg. L-1 total dissolved solids (TDS). The system was designed to produce 1 m3.h-1 of freshwater (permeate from the RO) and was operated by approximately 3 hours per day during twenty non-consecutive days. Samples from nine collection points were analyzed during the first (A), second (B) and third (C) hours of operation. In order to evaluate the water quality, the parameters evaluated were: TDS, electric conductivity, pH, temperature, apparent color, turbidity, total alkalinity, total hardness, calcium, chloride, sulfate, total coliforms and E.coli. To evaluate the efficiency of the system, the recovery rate and the filtration flow were calculated, as well as the reading of other operational parameters such as osmotic pressure. It was found absence of total coliforms and E. coli in the permeate. There was variation regarding to the removal of total hardness and calcium by the softener due to the regeneration time of the system. The RO system obtained an average of 99.4% of the TDS removal and the highest overall (UF and RO) recovery rate was 57.4%.
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Estabiliza??o de mol?culas bioativas presentes em suco de camucamu (Myrciaria d?bia (H.B.K) Mc Vaugh) pela integra??o dos processos de osmose inversa, evapora??o osm?tica e atomiza??o / Stabilization of bioactive molecules present in camucamu juice by means of interaction among the processes of reverse osmosis, osmotic evaporation and atomization

Souza, Andr? Luis Rodrigues 06 March 2012 (has links)
Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2017-04-27T13:51:34Z No. of bitstreams: 1 2012 - Andr? Luis R. de Souza.pdf: 1971622 bytes, checksum: 5237bc23d365c59e774d9f8776efabf1 (MD5) / Made available in DSpace on 2017-04-27T13:51:34Z (GMT). No. of bitstreams: 1 2012 - Andr? Luis R. de Souza.pdf: 1971622 bytes, checksum: 5237bc23d365c59e774d9f8776efabf1 (MD5) Previous issue date: 2012-03-06 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / Camu-camu is a native fruit from the Amazonian region, cultivated in the margins of rivers, lakes and Amazonian creeks called igarap?s. It is known as one of the fruit with the highest content of vitamin C. Reverse osmosis is a membrane concentration process in which the applied pressure is higher than the juice osmotic pressure. Such process favors the solvent permeation from the region with the highest concentration to the one with the lowest. Osmotic evaporation is another membrane concentration process in which a porous hydrophobic membrane separates the solution that is going to be concentrated from a concentrate brine solution. Microencapsulation is the process in which an active agent is entrapped by means of a polymer cover. Such process promotes the release of these active agents under specific conditions. The aim of this work is to evaluate the use of membrane separation processes and microencapsulation for the processing of camu-camu fruits. The camu-camu pulp, which has been obtained through the depulping of camu-camu fruits, was first centrifuged, in order to decrease its suspended solids content, and clarified by microfiltration with polysulfone membranes. Six clarification processes have carried out at 2.5 bar transmembrane pressure and 45?C. The clarified juice was concentrated by reverse osmosis at 60 bar and 20 ?C. The avarage permeate flux has been of 11.3 L/hm2. The preconcentrated juice had 28.8?Brix and the concentration degree of the process was 3.8. The pre-concentrated juice has been concentrated by osmotic evaporation in a laboratorial system with polytetrafluoroethylene membrane. The process presented an average pemeate flux of 2.4 Kg/hm2. The soluble solids content of the concentrated juice was of 56.6 ?Brix, presenting a concentration degree of 1.98. The retentate fraction of the microfiltration process was microencapsulated in a spray dryer. Three encapsulation agents were evaluated: starch, maltodextrin and the mixture of both. The values presented for the physicochemical caracterization of the pre-concentrated and concentrated camu-camu juices indicate that there has been an increase both in the physical characteristics of the juice, such as soluble solids, total solids and acidity, and in the concentration of camu-camu bioactive compounds. The dehydrated camu-camu juice presented a high concentration of bioactive substances. Nevertheless, there has been no stability of such compounds during storage. Through the results obtained in the present work, it is possible to observe that the integration of membrane processes proved efficient in the concentration of camu-camu juice, with a final product of high nutritional value / O camu-camu ? um fruto nativo da regi?o amaz?nica, cultivado as margens de rios, lagos e igarap?s. ? reconhecido como um dos frutos com um dos maiores teores de vitamina C. Osmose inversa ? o processo de concentra??o por membranas onde a press?o aplicada ? maior que a press?o osm?tica do suco, favorecendo a permea??o do solvente da regi?o de maior concentra??o para regi?o de menor concentra??o. Evapora??o osm?tica ? um outro processo de concentra??o, onde uma membrana hidrof?bica porosa separa a solu??o que ser? concentrada e uma salmoura concentrada. A microencapsula??o ? o processo onde um agente ativo ? protegido por meio de uma cobertura de pol?meros, ocorrendo a libera??o desses agentes ativos em condi??es espec?ficas. O objetivo desta disserta??o foi avaliar o uso dos processos de separa??o com membranas e microencapsulamento para o processamento de suco de camu-camu. Os frutos de camu-camu foram despolpados, sendo o suco submetido a centrifuga??o, com o objetivo de reduzir os s?lidos em suspens?o, e posteriormente clarificado por microfiltra??o em um sistema de membranas de polissulfona. Foram realizados seis processos de clarifica??o a 2,5 bar e 45?C. O suco clarificado foi pr?-concentrado por osmose inversa a 60 bar e 20 ?C. O fluxo permeado m?dio foi de 11,3 L/hm2. O suco pr?-concentrado apresentou teor de s?lidos sol?veis de 28,8?Brix e grau de concentra??o de 3,8. O suco pr?-concentrado foi processado por evapora??o osm?tica em um sistema laboratorial constitu?do por membranas de politetrafluoretileno. O processo apresentou fluxo m?dio permeado de 2,4 kg/hm2. O teor de s?lidos sol?veis do suco concentrado foi de 56,6 ?Brix, apresentando um grau de concentra??o de 1,98. O processo de microencapsula??o da fra??o retida do suco de camucamu foi realizado em um spray dryer Buchi Modelo B-190. Foram realizados tr?s ensaios com tr?s formula??es diferentes: mistura entre amido e maltodextrina, somente amido e somente maltodextrina. Os valores apresentados para a caracteriza??o f?sico-qu?mica do suco de camu-camu pr?-concentrado e concentrado indicam que houve um aumento nos s?lidos sol?veis e totais e da acidez, bem como no teor das subst?ncias bioativas do camucamu. O suco de camu-camu desidratado apresentou alto teor de subst?ncias bioativas, onde a estabilidade desses compostos durante o per?odo de armazenamento n?o foi alcan?ada. Observa-se que a integra??o dos processos com membranas se mostrou eficaz na concentra??o do suco de camu-camu, obtendo um produto com alta qualidade nutricional.

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