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Hidrólise contínua de sacarose em um reator enzimático com membrana / Continuous hydrolysis of sucrose on a enzymatic reactor with membraneAdriana Celia Lucarini 08 December 2003 (has links)
Reatores enzimáticos com membrana (REM) combinam muitas das características desejáveis em um bioprocesso, tais como: reator de elevada produtividade, reprodutibilidade no tempo, fácil controle e automação, operação em regime contínuo, eficiente separação de biocatalisador, substratos e produtos, com a viabilidade do uso de enzimas sem necessidade de imobilização. Este estudo faz parte do desenvolvimento e otimização de um bioprocesso que utiliza um reator enzimático com membrana com a enzima invertase, que catalisa a hidrólise da sacarose produzindo uma mistura equimolar de glicose e frutose. Estudou-se a influência de algumas variáveis operacionais e de reação no comportamento do REM. Este reator consiste de um tanque agitado de 50 mL onde células de Saccharomyces cerevisiae, contendo a invertase, ficam retidas por meio de uma membrana (Øporo 0,45µm), disposta na parte inferior do sistema. A configuração deste é semelhante a um reator contínuo tipo tanque agitado (CSTR). Inicialmente, avaliou-se a influência das variáveis: concentração de sacarose e concentração de enzima, por meio de experimentos seriais, que possibilitaram fixar estas variáveis em níveis adequados, de 500 mM e 1 mg/mL, respectivamente, para a continuidade dos ensaios por meio de planejamentos experimentais fatoriais. Foi utilizado um planejamento experimental (23 + estrela) e a análise de superfície de resposta para avaliar a influência das variáveis: vazão de alimentação do substrato, temperatura e pH. Para a análise estatística dos resultados, utilizaram-se como respostas o grau de conversão da sacarose e a produtividade em frutose, determinadas em amostragens feitas durante o tempo de operação do reator, em média de 8 a 9 horas por condição avaliada. Dos resultados obtidos, mostraram-se significativos, com 95% de confiança, os efeitos lineares e quadráticos da vazão e temperatura. As condições ótimas encontradas foram: vazão de alimentação entre 0,4 e 1,0 mL/min e temperatura 51°C. O grau de conversão obtido foi de aproximadamente 95%, com as seguintes condições experimentais: concentração da suspensão de células de 1mg/mL, temperatura de 51°C, pH 5,5; concentrações de sacarose de 500 mM e vazão de alimentação de 1,0 mL/min. Para esta condição obteve-se uma produtividade da ordem de 0,6 mmol frutose/h.mg invertase. Os desvios entre os valores previstos pelo modelo estatístico e pelo modelo experimental foram da ordem de 3%. Em função dos resultados obtidos neste trabalho concluiu-se que esta concepção de reator é eficiente para a bioconversão da sacarose e, portanto, o processo contínuo com reator com membrana é promissor para o desenvolvimento de processos enzimáticos desta natureza. / Enzymatic membrane reactors combine several desirable characteristics in a bioprocess, such as high productivity, reproducibility, easy control and automation, continuous operation, efficient separation of biocatalyst, substrate and products, and the use of enzymes without immobilization. This work is part of the development and optimization of a bioprocess using an enzymatic reactor which utilizes a membrane reactor for the enzymatic hydrolysis of sucrose in a solution of fructose and glucose, containing the enzyme invertase. The influence of some operational and reaction variables on the performance of the membrane reactor was studied. The bioreactor consisted of a 50 mL-stirred tank where intact cells of Saccharomyces cerevisiae, containing invertase in the cell wall, are retained inside the reactor by a microfiltration membrane (Øpore 0.45µm). The flat sheet membrane is fixed at the bottom of the device. The reactor configuration is similar to a continuous stirred tank reactor (CSTR). Initially, the influence of sucrose and enzyme concentration was evaluated through a series of experiments in order to determine the suitable levels of these variables. Sucrose was set to 500 mM and enzyme set to 1 mg/mL. This allowed the work to continue by means of experimental factorial designs. It was utilized a 23 full experimental design followed by a 2nd order statistical design and, the surface response methodology in order to evaluate the influence of volume feeding rate of the substrate, temperature and pH on fructose productivity and sucrose conversion. The values were obtained during the reactor operation. The average operation time was trom 8 to 9 hours for all evaluated conditions. From the statistical analysis, it was concluded that the linear and quadratic effects of temperature and flow rate on the results were the most significant with 95% of confidence. The optimum conditions found for this bioprocess were volume feeding rate between 0.4 and 1.0 mL/min and temperature of 51°C. The degree of conversion of sucrose obtained experimentally was 95%, in the following experimental conditions: cell concentration of 1mg/mL, temperature of 51°C, pH 5.5; sucrose concentration of 500 mM and feeding rate of 1.0 mL/min. For this operational condition it was obtained a productivity of about 0.6 mmol fructose/h.mg invertase. The deviation between the predicted values by the statistical model and the experimental data was 3%. Based on the results obtained in this work, it can be concluded that this conception of bioreactor is efficient for the bioconversion of sucrose and, a continuous membrane reactor process is very promising for the development of this kind of enzymatic process.
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Produ??o, concentra??o e caracteriza??o parcial de extrato celulol?tico produzido por linhagem f?ngica mutanteSantos, Alex da Silva 28 February 2011 (has links)
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Previous issue date: 2011-02-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior, CAPES / The production of enzymes for application at different areas of food agroindustry presents promising future perspectives, due to several intrinsic properties regarded to the performance of the enzymes as natural and biodegradable compounds, responsible for achieving specific reactions with better quality. Cellulases have been the most employed enzymes on food industry, acting sinergically on the hydrolysis of the glucosidic links ?-1,4 from the molecules of cellulose, and being used on several applications in this sector as in vegetal oils extraction, fruit maceration and juice clarification. Based on this context, the present study aimed to produce, concentrate and partially characterize an enzymatic extract by a mutant fungus strain of Aspergillus niger. Production was performed by solid-state fermentation (SSF) in aerated columns, using humidified wheat bran with (NH4)2SO4 solution on 0,1N HCl as substrate and cellobiose as inducer. Cellulolytic extract was a blend of extracts from three different assays selected on previous studies as the best conditions for the enzymes caboxymethilcellulase, ?-glucosidase and filter paper cellulose (FPase). During the characterization of the enzymatic extract, besides cellulases activity, the presence of protease and other enzymes with similar action to cellulases as xylanase and poligalacturonase was evaluated. For enzymatic extract concentration, three different strategies were performed: ultrafiltration, using a stainless steel plates system through a 20 kDa molecular weight cut-off polyethersulphone membrane and 0,014 m2 area; precipitation with ammonium sulphate under 20%, 40 %, 60% and 80% saturation level and lyophiilization. The best results were achieved by the ultrafiltration process, partially purified sample and providing enzymatic activities recovery between 75% and 99%, except for FPase. SDS-PAGE analysis presented 15 visible protein bands on cellulolytic extract with molecular weights ranging from 13.3 to 104.6 kDa. Zymography test was applied for cellulases and correlate enzymes as well as to protease, however, just for the last one the conditions were considered appropriate, identifying bands on 88, 103 and 145 kDa. The effective performance of ?-glucosidase and xylanase over xylan and cellobiose hydrolysis was confirmed by thin layer chromatography. A central rotational statistical design 22 with 4 central points was used for evaluating optimal temperature and pH for carboxymethylcellulase and ?-glucosidase. The analysis of the results obtained for both enzymes demonstrated that all variables were significative at a 95% confidence level. Based on the conditions studied it can be concluded that optimal pH and temperature ranges for efficient and combined action of carboxymethylcellulase and ?-glucosidase are 3.7 to 5.5 and 60 to 65?C, respectively. / A produ??o de enzimas para uso em diferentes ?reas da agroind?stria de alimentos mostra perspectivas futuras promissoras, devido ?s v?rias caracter?sticas inerentes ? a??o das enzimas que s?o compostos naturais, biodegrad?veis e capazes de desempenhar rea??es espec?ficas com melhor qualidade. Entre as enzimas mais utilizadas pelo setor de alimentos est?o as celulases, um complexo de enzimas que atuam de forma sin?rgica sobre a hidr?lise das liga??es glicos?dicas ?-1,4 das mol?culas de celulose, e possuem v?rias aplica??es industriais neste setor, como na extra??o de ?leos vegetais, na macera??o de frutas e na clarifica??o de sucos. Dentro deste contexto, este trabalho teve como objetivo produzir, concentrar e caracterizar parcialmente um extrato celulol?tico obtido por linhagem f?ngica mutante de Aspergillus niger. A produ??o foi realizada por fermenta??o no estado s?lido (FES) em colunas aeradas, utilizando como substrato farelo de trigo triturado umidificado com solu??o de (NH4)2SO4 em HCl 0,1N e celobiose, como indutor. O extrato celulol?tico consistiu de uma mistura de extratos obtidos em 3 ensaios fermentativos diferentes, selecionados em trabalhos anteriores como as melhores condi??es para produ??o de cada uma das enzimascarboximetilcelulase (CMCase), ?-glicosidase e celulase em papel de filtro (FPase). Durante a caracteriza??o do extrato enzim?tico, al?m da atividade das celulases, tamb?m era avaliado o teor de prote?na, a presen?a de protease e de enzimas correlatas ? a??o de celulases como xilanase e poligalacturonase. Para concentra??o do extrato enzim?tico foram realizadas tr?s diferentes estrat?gias: ultrafiltra??o em um sistema de quadro e placas em a?o inox, utilizando uma membrana de polietersulfona com massa molar de corte de 20 kDa e ?rea de 0,014m2; precipita??o com sulfato de am?nio utilizando satura??es de 20%, 40%, 50%, 60%, 80% e liofiliza??o. O processo de ultrafiltra??o foi o que obteve o melhor resultado, purificando parcialmente a amostra e proporcionando uma recupera??o das atividades enzim?ticas entre 75% e 99% para todas as atividades avaliadas, exceto FPase. A an?lise eletrofor?tica em SDS-PAGE demonstrou a presen?a de 15 bandas vis?veis de prote?nas no extrato celulol?tico com pesos moleculares que compreendem uma faixa entre 13,3 e 104,6 kD. O teste de zimografia foi realizado para as celulases e enzimas correlatas, bem como para protease, no entanto somente para esta ?ltima, as condi??es testadas foram adequadas tornando-se poss?vel identificar bandas em 88, 103 e 145 kDa. A efetiva a??o das enzimas ?-glicosidase e xilanase na hidr?lise de celobiose e xilana, respectivamente,foi comprovada em cromatografia de camada fina. Al?m disso, a temperatura e pH ?timos de atua??o de carboximetilcelulase e ?-glicosidase foram determinados utilizando o delineamento composto central rotacional 22, com 4 pontos centrais. A an?lise dos resultados de ambas as enzimas demonstrou que as vari?veis eram significativas, a um n?vel de confian?a de 95%. Com base nas condi??es estudadas, concluiu-se que as faixas de pH e temperatura ?timos para a atua??o eficiente e conjunta de CMCase e ?-glicosidase est?o entre 3,7 a 5,5 e 60 a 65 ?C, respectivamente.
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Transfert et transport colloïdal de polluants métalliques<br />Applications en assainissement routierDurin, Bertrand 02 June 2006 (has links) (PDF)
L'impact des infrastructures de transport sur l'environnement est une des préoccupations du ministère en charge de l'environnement. Le ruissellement des eaux de pluie sur les surfaces urbanisées engendre un effluent complexe plus ou moins pollué. L'objet de ce travail était de préciser le rôle de la fraction colloïdale sur la mobilité des éléments traces en assainissement routier. Pour cela nous avons procédé à deux échelles, d'une part d'une manière globale en instrumentant un bassin d'infiltration des eaux pluviales, afin de collecter et de qualifier l'effluent au cours de la chaîne d'infiltration depuis la route jusqu'aux eaux interstitielles ; d'autre part en simulant à l'échelle de la colonne de laboratoire, les sollicitations subies par le sédiment au cours de l'année, c'est à dire des variations de force ionique et des variations de charge hydraulique. L'isolement de la fraction colloïdale a été assurépar un protocole d'ultrafiltration et la caractérisation a été réalisée en couplant les analyses physicochimiques (ICP-AES, SAA, MEB, MEBE, MET, XPS) et un code de calcul géochimique. Les résultats obtenus sur le terrain mettent en évidence l'existence et la grande variabilité de la fraction colloïdale. Seul le cuivre y est toujours présent entre 4 et 59 % de sa concentration totale. Une méthodologie visant à réduire l'incertitude a été mise au point. La chute de la force ionique entraîne une mobilisation colloïdale d'aluminium, de cuivre, de plomb et de matière organique, alors que les cycles d'arrêt-reprise du débit mobilisent le cuivre, le fer, le zinc, le nickel et des composés organiques. La caractérisation colloïdale des éluats montre que les éléments traces sont associés à des oxydes d'aluminium et de fer accompagnés de substances organiques issues de la dégradation biologique mais qui sont à identifier.
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ETUDE NUMERIQUE DES TRANSFERTS DANS UN TUBE A PAROI POREUSE SOUMIS A UNE ASPIRATION PARIETALEDamak, Kamel 07 June 2004 (has links) (PDF)
La caractérisation du champ hydrodynamique et du champ de concentration, dans un tube à paroi poreuse soumis à une aspiration pariétale, est établie à l'aide d'un modèle physique traduisant les transferts simultanés d'impulsion et de matière en supposant un écoulement laminaire en régime permanent et une suspension assimilé à un fluide newtonien incompressible. Les forces de volume sont négligeables. Le coefficient de diffusion de matière est supposé constant. Cette caractérisation se base sur la résolution des équations de Navier-Stocks, qui caractérisent l'écoulement libre dans le tube, et la loi de Darcy qui traduit l'écoulement à la paroi poreuse. L'analyse dimensionnelle des équations de transfert a permis d'apparaître trois paramètres adimensionnels qui sont le nombre de Reynolds axial (Re), le nombre de Reynolds de perméation (Rew) et le nombre de Schmidt (Sc). Nous avons mis au point un code de calcul, développé sous environnement Matlab, basé sur une méthode aux différences finies. Ce code permet la détermination des profils des champs de vitesse, de pression et de concentration. Il est composé principalement de trois parties permettant la saisie des données, la résolution des équations considérées et l'affichage des résultats. Ce code est validé en effectuant deux tests, le premier consiste à retrouver numériquement les résultés analytiques d'un écoulement de Poiseuille dans in tube lisse, le recouvrement entre les résultats numériques et analytiques est parfait. Le deuxième test se refaire à des résultats expérimentaux déterminés par Gouverneur (1991) pour une vitesse de perméation non nulle. Dans ce cas l'erreur entre les résultats expérimentaux et numériques est inférieure à 1%. Nous avons alors exploité le code du calcul pour étudier l'écoulement dans un tube à paroi poreuse d'un fluide pur et d'un fluide chargé de particules. La première étude a permis de mettre en évidence l'influence des nombres de Reynolds axial et de Reynolds de perméation sur les profils des vitesses axiale et radiale, et sur les pertes de charge dans le tube. La seconde étude introduit l'équation de convection-diffusion de la matière. Elle prend en considération la formation d'une couche de dépôt de particules sur la paroi poreuse, pour se rapprocher de la réalité des phénomènes qui se reproduisent lors de la filtration tangentielle. La principale conséquence de la formation de cette couche est la non uniformité de la vitesse de perméation. L'étude montre l'influence des divers nombres adimensionnels sur l'épaisseur de la couche de dépôt, en particulier l'influence du nombre de Reynolds de perméation. Les résultats numériques ont été corrélés sous forme d'une équation, qui exprime l'évolution relative de l'épaisseur de la couche limite de concentration, en utilisant la méthode des moindres carrées . Notre travail est une contribution à l'étude hydrodynamique et à l'étude du dépôt des particules, qui se forme à la surface perméable d'un tube de filtration tangentielle, en supposant que la porosité de ce dépôt constante. Il convient d'élargir cette étude pour examiner les mêmes évolutions en supposant un dépôt compressible et de tenir compte de la porosité locale de ce dépôt.
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Avaliação dos efeitos do betabloqueador nebivolol sobre o peritônio em modelo experimental murino de diálise peritoneal / Assessment of the effects of beta-blocker nebivolol on the peritoneum in an experimental murine model of peritoneal dialysisAnna Rita Moraes de Souza Aguirre Mazo 20 October 2011 (has links)
A falência de ultrafiltração (UFF) é uma causa importante de interrupção da diálise peritoneal (DP) enquanto terapia renal substitutiva. Além da inflamação crônica e aguda causadas à membrana peritoneal (MP) pelos produtos de degradação da glicose, produtos avançados da glicosilação, pH ácido das soluções e infecções, -bloqueadores (BB) também foram implicados na gênese da UFF. A vasoconstrição arteriolar esplâncnica é considerada a causa provável da UFF por BB. O nebivolol (NV), um bloqueador 1-adrenérgico altamente seletivo que, diferente de outros BB, possui efeito vasodilatador por aumento de óxido nítrico (NO) por ativar a via L-arginina-NO, foi testado em pacientes idosos com ICC e levou à redução na mortalidade. O objetivo desse estudo é analisar os efeitos do NV sobre a ultrafiltração (UF), MP e características do efluente em um modelo animal de DP, através do estudo de fenômenos envolvidos na degeneração da MP e UFF, como transição epitélio mesenquimal (EMT) e fibrose, além de parâmetros humorais e celulares de inflamação. 21 camundongos C57BL/6 fêmeas, não urêmicos, com 12 a 14 semanas, foram submetidos à colocação de cateter peritoneal. Após uma semana, foram divididos em 3 grupos de 7 animais: grupo controle (observação 30 dias), grupo SDP (2 mL/ dia de solução glicosada de diálise peritoneal a 4,25% através do cateter, por 30 dias) e grupo NV (além da infusão, receberam 8 mg/kg/dia de NV por gavagem, por 30 dias). Após 30 dias, comparou-se espessura submesotelial, volume de UF, velocidades de transporte de pequenos solutos, marcação submesotelial de pan-citoqueratina, para quantificar EMT, contagem de vasos, linfangiogênese diafragmática e concentração de IL-6 e IL-10 no efluente. A espessura da MP foi de 23,14 m no grupo controle, no grupo SDP foi de 102,4 m e no grupo NV, 29,04 m, com p<0,05. O volume de UF foi 1,94mL para o grupo controle, para o grupo SDP, 1,56 mL e, para o grupo NV, 2,05 mL, também com p<0,05. Houve menor EMT, menor angiogênese e tendência a transporte mais lento de solutos no grupo tratado, assim como menor concentração de IL-6 e proporções de populações de linfócitos semelhantes às do grupo controle. Concluímos que a droga impediu o desenvolvimento de UFF, através do bloqueio de fenômenos como EMT, espessamento da MP e neoangiogênese, além de preservar características de imunidade celular e humoral locais, merecendo ser estudada em pacientes submetidos à DP / Ultrafiltration failure (UFF) is a major cause of peritoneal dialysis (PD) discontinuation. Besides peritoneal membrane (PM) acute and chronic inflammation caused by glucose degradation products, advanced glycation end-products, acidic pH of the solutions and peritoneal infections, also -blockers (BBs) have been implicated in UFF genesis. Splanchnic arteriolar vasoconstriction has been considered the probable cause of UFF induced by BBs. Nebivolol (NV), a highly selective 1-adrenergic blocker, unlike other BBs, has a vasodilatory effect caused by its ability to increase nitric oxide (NO) through L-arginine-NO pathway activation. NV has been tested in elderly patients with congestive heart failure and led to mortality reduction. The aim of this work is to analyze the effects of NV over ultrafiltration (UF), PM and effluent characteristics in an animal model of PD. For that end, phenomena known to be involved in PM degeneration and UFF, such as epithelial-to-mesenchymal transition (EMT), fibrosis, as well as cellular and humoral parameters of inflammation have been studied. 21 C57BL/ 6 female non uremic mice, ageing 12 to 14 weeks, underwent peritoneal catheter placement. One week later, they were divided into 3 groups of 7 animals: control group (observation for 30 day), PDF group (2 mL/ day of 4.25% dextrose peritoneal dialysis fluid injected through the catheter for 30 days) and NV group (besides the PDF infusion, this group received 8 mg/ kg/ day of NV by gavage, for 30 days). After 30 days, submesotelial thickness, UF volume, small solute transport speed, submesotelial pan-cytokeratin staining (EMT quantification), vessel count, diaphragmatic lymphangiogenesis and IL-6 and IL-10 concentrations in the effluent were compared. PM thickness was 23.14 m in the control group, 102.4 m in the PDF group and 29.04 m in the NV group, p <0.05. UF volume was 1.94 mL in the control group, 1.56 mL in the SDP group, and in the NV group, 2.05 mL, p <0.05. There was less EMT, less angiogenesis and a tendency to a slower solute transport in the treated group. Lower levels of IL-6 and similar lymphocyte populations proportions to the control group were also found. We conclude that the drug can prevent UFF development, through blockade of phenomena such as EMT, PM thickening and neoangiogenesis, while characteristics of local cellular and humoral immunity were preserved. These results warrant a clinical study of the drug in PD patients
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Establishing a sustainable water supply in Chonyonyo, Karagwe, TanzaniaHolmberg, Kristin January 2017 (has links)
The small village Chonyonyo, in the district Karagwe in the northwest of Tanzania has a shortage of safe drinking water. Women and children spend several hours a day fetching water and gathering firewood to boil the water to make it more suitable for drinking. The need of new sustainable water supply solutions is fundamental for providing more people with safe drinking water. Two water distribution alternatives was suggested by Engineers Without Borders and MAVUNO as possible solutions to supply the community with water. Alternative 1 consisted of a 10 km distribution system from an already existing groundwater well at the MAVUNO office to Chonyonyo. Alternative 2 consisted of a 3.5 km distribution system from the most neighboring valley to Chonyonyo, where no groundwater well exists today. Both alternatives would be powered by solar panels and operated six hours a day. The most sustainable distribution solution was chosen by modeling the distribution alternatives in the modeling software EPANET. Input parameters to simulate the model were position, elevation and dimension of storage tanks and pipes. Other required input parameters were absolute roughness, water withdrawal, operation hours, description of the withdrawal pattern for the water outlet and other modelling conditions such as a suitable simulation time. The selection of water distribution system was based on minimum requirements of energy used for operation weighed with lowest possible water residence time in the storage tank. Water quality analyses of the raw water source for distribution alternative 1 were performed in order to classify the water and select suitable water treatment solutions. The analyses consisted of microbiological and metal/metalloid analyses, and measurements of EC and pH. The result of the simulation showed that neither of the distribution alternatives met all the pipe design criteria. The main reason is that the system can not be constantly operated. If this criterion is excluded the optimal solution is distribution alternative 1 with an outer pipe diameter of 110 mm throughout the whole distribution system and a water residence time in the storage tank of 57.1 hours. The water quality analysis showed that the ground water source for distribution alternative 1 was affected by surface water and is thus classified as unusable because of high levels of harmful bacteria and lead. The most suitable water treatment solution due to the aspects of sustainable water supply are the microbiological barriers ultrafiltration and UV-light in combination with a treatment method to remove lead from the water. / I samhället Chonyonyo i distriktet Karagwe i nordvästra Tanzania råder brist på säkert dricksvatten. Kvinnor och barn spenderar flera timmar om dagen för att hämta vatten och samla ved för att koka vattnet så att det blir säkrare att dricka. Behovet av nya hållbara vattenlösningar är fundamental för att kunna försörja fler människor med säkert dricksvatten. Två vattendistributionsalternativ lades fram av Ingenjörer utan gränser och MAVUNO som möjliga lösningar för att försörja invånarna i Chonyonyo med dricksvatten. Alternativ 1 bestod av ett 10 km distributionssystem från en befintlig grundvattenbrunn vid MAVUNO:s kontor. Alternativ 2 bestod av ett 3.5 km distributionssystem från den närmaste dalen till samhället Chonyonyo, där det inte finns någon befintlig grundvattenbrunn. Båda alternativen kommer att drivas av solpaneler och vara under drift sex timmar per dygn. Det lämpligaste distributionsalternativet valdes ut genom simulering i mjukvaran EPANET. Ingångsparametrar för simuleringen var bl.a. position, höjd och dimension på reservoarer och ledningar. Ytterligare nödvändiga parametrar var skrovlighet på ledningar, storlek på vattenuttag, antal driftstimmar, uttagmönster från vattenkranar i systemet samt andra modelleringsförhållanden såsom en lämplig simuleringstid. Valet av distributionssystem grundades på lägsta möjliga energibehov för drift viktat mot lägsta möjliga uppehållstid i vattenreservoarerna. Kvalitetsanalyser av råvattnet för distributionsalternativ 1 genomfördes för att klassificera vattnet och göra lämpliga val av vattenreningslösningar. Analyserna omfattade mätning av ett antal mikrobiologiska parametrar, metaller/metalloider samt EC och pH. Simuleringen visade att ingen av alternativen kunde uppnå alla designkriterierna. Huvudorsaken till det är att systemet endast är i drift periodvis. Bortsett från dessa kriterier var det optimala lösningen distributionsalternativ 1 med en yttre rördiameter på 110 mm genom hela systemet med en maximal uppehållstid i vattenreservoaren på ca 57 timmar. Analyserna visade att grundvattnet var ytvattenpåverkat och klassificeras som otjänligt med höga nivåer av skadliga bakterier och bly. De lämpligaste vattenreningslösningarna i förhållande till hållbarhetsaspekterna var de mikrobiologiska barriärerna ultrafiltrering och behandling med UV-ljus kombinerat med en reningsmetod för att avskilja bly från vattnet.
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Využití membrán pro zpracování odpadních vod ze zemědělství / Membrane technologies for agricultural wastewater treatmentUhlířová, Marcela January 2021 (has links)
This thesis deals with an agricultural wastewater treatment (liquid digestate) by membrane technology. There is a fundamental description of characteristics of membrane technology with regard to application of agricultural wastewater treatment in this thesis. Experimental device for treatment of liquid digestate is designed and it consists of three steps – microfiltration, ultrafiltration and reverse osmosis. The first step consists of four filters with different pore sizes (80, 25, 10 and 5 µm). The second step is ultrafiltration and the third and key step is reverse osmosis. In the final step monovalent ions such as NH4+ are separated. Reverse osmosis consists of two stage system which results in higher recovery. Three experiments were carried out in order to verify the efficiency of separation dissolved solids.
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Studium průniku „musk“ sloučenin do abiotických a biotických složek vodních ekosystémů / Study of Transfer of Musk Compounds in Abiotic and Biotic Components of Aquatic EcosystemsZouhar, Libor January 2013 (has links)
This work was focused on the determination of musk compounds in various components of the environment. Synthetic musk compounds are organic substances commonly used as fragrant constituents of detergents, perfumes, cosmetics and other personal care products (PCPs). These compounds contaminate the aquatic environment through municipal wastewater from sewage treatment plants. The result is accumulation of these analytes in the environment and their occurrence in food chain. Synthetic fragrances are commonly detected also in human body; these substances generally belong among relatively new persistent organic pollutants (POPs) because of their persistence, bioaccumulation, and potential toxicity. The aim of this work was to optimize the methods for the determination of selected synthetic fragrances in wastewater (municipal, industrial) and in fish muscle. These analytes were determined in wastewater [the wastewater treatment plant (WWTP) Brno – Modřice, cosmetic manufacturing plant] and in fish Squalius cephalus that had been caught in the river Svratka. The selected analytes (14 substances) originate from the group of nitromusk, polycyclic musk and linear musk compounds. Solid phase microextraction (SPME) [for wastewater samples] and pressurized solvent extraction (PSE) [for fish samples] were used for isolation of analytes from real samples. The identification and quantification of analytes were carried out by high resolution gas chromatography coupled with mass spectrometry detection (GC-MS). The results show that galaxolide (g.L-1) and tonalide (tenths of g.L-1) were polycyclic musk compounds which were found at the highest concentration level in influent and also in effluent samples from the WWTP Brno – Modřice. The most extended nitromusk compound was musk ketone (hundredths of g.L-1). Linear musk compounds were detected in all influent samples (g.L-1). The overall removal efficiency of synthetic musk compounds from wastewater in the WWTP varies within the following ranges: nitromusk compounds 34.4 % – 85.4 %, polycyclic musk compounds 36.7 % – 53.3 % and linear musk compounds 90.5 % – 99.9 %. On the basis of the results it can be stated that wastewater (effluent from the WWTP) is the primary source of musk compounds, especially of the polycyclic ones in the environment. It has been also shown that ultrafiltration used in a cosmetic plant is a highly efficient technology for removing nitromusk and polycyclic musk compounds from industry wastewater. The results from evaluation of the fish contamination by musk compounds show that galaxolide was the substance which reached the highest concentration levels (tens of g.kg-1 l.w.). The results corroborate ubiquitous occurrence of musk compounds in the environment and reduction of using of nitromusk compounds due to their potential toxic properties. It has been shown that the insufficiency of the purifying procedures used in the WWTP Brno – Modřice has a significant influence on the concentration level of polycyclic musk compounds (tonalide, galaxolide) in fish caught from the river Svratka.
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Preparation of Non-Surface-Active Solutions from Bovine Milk and Dairy-Based Beverages to Improve Langmuir Trough Model Systems of Dairy FluidsReal Hernandez, Luis M. January 2018 (has links)
No description available.
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390 |
Transport Phenomena in Polymeric Blends and Multilayer FilmsFeng, Jingxing 23 May 2019 (has links)
No description available.
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