Contaminantes orgânicos há tempos são normalmente encontrados em baixíssimas concentrações no meio ambiente. Compostos orgânicos monoaromáticos, derivados dos subprodutos do petróleo, frequentemente são encontrados próximos a postos de combustíveis, onde há constantes vazamentos nos tanques de armazenamento. Poluentes emergentes, como exemplo os fármacos, também são temas constantes de pesquisas, devido à baixa taxa de degradação dos mesmos, mesmo após submetidos a sistemas de tratamento convencionais. Assim, a busca por técnicas de remediação, que visem a completa remoção de poluentes em baixas concentrações e metodologias analíticas que permitam o isolamento e detecção de tais compostos se torna essencial. Esse trabalho tem como uma de suas finalidades otimizar e aplicar um sistema de remoção de compostos orgânicos monoaromáticos presentes em solo, utilizando CO2 no estado supercrítico. A SPME-GC-MS foi otimizada e validada para a etapa de extração, com separação e quantificação por GC-MS dos contaminantes remanescentes após o solo ser submetido ao processo de remediação. Outro etapa do projeto, está relacionada com a determinação de sulfonamidas em lodo de esgoto. Para isso, um método rápido, fácil, barato e robusto de extração foi otimizado e validado, obtendo bons limites de quantificação (10-25 ng g-1) e detecção (4-9 ng g-1), com precisão e exatidão satisfatórios, de acordo com os valores estabelecidos pela ANVISA. Ainda com o propósito de determinar sulfonamidas em lodo de esgoto, um método LC online foi desenvolvido. A finalidade é promover o clean-up da matriz e extração dos analitos em um sistema de extração em fase sólida capilar online. Para isso, fez uso de duas colunas capilares (530 µm x 6,0 cm) dispostas em série, inseridas em um sistema cromatográfico capilar acoplado a detecção por espectrometria de massas. A primeira coluna teve como finalidade a retenção de interferentes presentes na amostra utilizando para isso, uma fase polimérica Strata-X. Já a segunda coluna, extraiu as sulfonamidas de interesse utilizando, para isso, uma fase polimérica aniônica Oasis Max. O extrato inserido no sistema de extração em fase sólida onlineera composto por 100 % solvente orgânico (acetonitrila); utilizando diferentes porcentagens de acetonitrila na etapa de carregamento, foi possível realizar clean-up adequado da amostra. A eluição dos analitos foi feita utilizando-se fase móvel acidificada. Com esse sistema, melhorou-se em até 30 % a extração de alguns compostos. Todos os métodos de preparo de amostra utilizados no trabalhos seguem a tendência atual sugerida pelo conceito do green chemistry. / The determination of organic contaminants in environmental matrices has long been a challenge for the scientific community, due to the very low concentrations they are present. Monoaromatic organiccompounds derived from petroleum sub-products are still a concern, because they are often found in environmental sites near gas stations, where there are constant leaks in storage tanks. Emerging pollutants,which include personal care products and pharmaceuticals, are also constant subject of research due to their low degradation rate, even after conventional treatment systems. Moreover, the research forremediation techniques aimed at complete removal of pollutants at low concentrations, as weel as new analytical methodologies for isolation and detection of such compounds are, both, essential. This workaims to optimize and apply a system to remove monoaromatic organic compounds present in soil, using CO2 in the supercritical state. As an analytical tool, SPME was optimized and validated with separation and quantification by GC-MS of selected contaminants remaining after the remediation process. Another research work developed is related to the determination of sulfonamides in sewage sludge.Firstly a methodology based on QuEChERS extraction method was optimized and validated, obtaining good results as limits of quantification, LOQ (10-25 ng g-1) and detection, LOD (4-9 ng g-1) withsatisfactory accuracy and precision, according to the values established by ANVISA. Still working to determine sulfonamides in sewage sludge, a new online sample preparation method was developed. Thepurpose of this method is to promote the matrix clean-up and concentration analytes in a capillary SPE system. It was used two capillary columns (500 µm x 6.0 cm) arranged in series in a capillarychromatographic system coupled to mass spectrometry. The first column was intended to retain interferences present in the sample, using a Strata-X polymer phase. The second column extracted sulfonamidesof interest, making use of an anionic polymer phase (Oasis MAX). The extract inserted in the online SPE system was composed of 100% organic solvent (acetonitrile); using different percentages of ACNwith appropriately pH at the loading stage, it was possible to achieve a satisfatory sample clean-up. The elution of the analytes was performed using an acidified mobile phase. This system improved by up to30% extraction yield of some compounds. All sample preparation methods used in the works follow the current trend suggested by the green chemistry concept.

Made available in DSpace on 2017-05-12T14:47:16Z (GMT). No. of bitstreams: 1 Luciana_ Graciano.pdf: 1359694 bytes, checksum: 9321745e3e0faea5a21d91af3579b01a (MD5) Previous issue date: 2015-02-27 / The optimization of xylanase production of a new Aspergillus fumigatus Fresen strain (OI-1RT) was obtained by statistical approaches. The Plackett-Burman Design evaluation showed that the following components of Czapeck medium were biologically significant: sodium nitrate, potassium phosphate, magnesium sulfate and corn straw. These factors were selected to implement the 24 Central Composite Rotational Delineation with the proposed model validation. The response surface plots have indicated a trend for increased xylanase activity with increasing concentrations of maize straw. An additional test was carried out with different concentrations of maize straw and the optimized xylanase activity was 530 U ml-1 in the presence of 6.5% (w / v) of residual biomass, which was 11 times higher than the one obtained only with the Plackett-Burman Planning (45.8 U mL-1). The thermostability of the enzyme was kept at 90% at 50 °C for 6 hours. Enzyma tic hydrolyses tests were performed to obtain reducing sugars from maize straw, hydrolyzed maize straw and beechwood xylan. This procedure has been performed for 96 hours with 2 U ml-1 for xylanase (crude extract) and resulted in net production of 3.89, 20.96 and 21.64 μmol mL-1 for reducing sugars, respectively. This indicated possible biotechnological applications to the crude extract with xylan-degrading enzymes (xylanase). / As xilanases são glicosídeo hidrolases (GHs) com diferentes propriedades físico-químicas e várias aplicações biotecnológicas, como na indústria têxtil, alimentícia e de papel e celulose. Xilanases podem ser utilizadas para a degradação de fontes de carbono renováveis, tais como os resíduos agroindustriais. Desta forma, é possível aproveitar a capacidade energética de compostos disponíveis em abundância e que poderiam ser descartados levando à poluição de solos e corpos hídricos. Atualmente, existe uma busca por estratégias que permitam a otimização de processos biotecnológicos para utilizar a capacidade energética presentes na biomassa para geração de produtos de valor agregado, como a produção de xilitol e do etanol celulósico. Ferramentas bioquímico-moleculares e planejamentos estatísticos de otimização de processos são exemplos de estratégias que visam melhorar o desempenho catalítico de enzimas. Neste contexto, este trabalho objetivou aproveitar resíduos agroindustriais para a indução de xilanases usando duas abordagens. Na primeira, foi realizada a clonagem e expressão do gene xynA1 (CCNA_02894) de Caulobacter crescentus em Escherichia coli com a obtenção de uma proteína recombinante fusionada a uma cauda de histidina carboxi-terminal (XynA1), que foi posteriormente purificada e caracterizada quanto a suas propriedades bioquímicas e cinéticas. Nesta análise, verificou-se que dentre as várias fontes de carbono testadas para indução da XynA1 em C. crescentus, os substratos palha de milho, palha de milho hidrolisada e o sabugo de milho foram os mais eficientes para induzir a atividade xilanásica. Além disso, a caracterização da XynA pura, obtida por cromatografia de afinidade em colunas préempacotadas de níquel-sepharose de elevado desempenho, mostrou que a XynA1 possui atividade enzimática e atividade específica de 18,26 U mL-1 e 2,22 e U mg-1usando xilano de beechwood como substrato na reação. A atividade de XynA1 foi inibida por EDTA e íons metálicos tais como Cu 2+ e Mg 2+. Em contraste, ß-mercaptoetanol, ditiotreitol (DTT), e Ca2+ induziram a atividade da enzima recombinante. Os dados cinéticos para XynA1 revelaram valores de KM e Vmáx de 3,77 mg mL-1 e 10,2 μM min-1, respectivamente. Finalmente, a enzima apresentou um pH ótimo igual a 6 e temperatura ótima de 50 °C. Além disso, 80% da atividade de XynA1 foi mantida a 50 °C por 4 hor as de incubação. Isso sugere estabilidade térmica para aplicação em processos biotecnológicos. Na segunda etapa do trabalho, foi realizada a otimização da produção xilanásica por um novo isolado vii termotolerante de Aspergillus fumigatus Fresen. (OI-1R-T), obtido de bioma de Mata Atlântica, usando metodologias estatísticas de delineamento experimental como Planejamento Plackett-Burman (Plackett-Burman Design-PBD) e Delineamento Composto Central Rotacional (DCCR). Verificou-se, nesses ensaios, uma atividade xilanásica de 530 U mL-1 na presença de 6,5% de palha de milho no meio de cultivo otimizado. Ensaios de hidrólises enzimáticas da palha de milho, palha de milho hidrolisada e do xilano de beechwood foram realizados durante 96 horas com 2 U mL-1 de atividade xilanásica do extrato bruto otimizado no mesmo resíduo, resultando em uma produção líquida de 3,89, 20,96 e 21,64 μmol mL-1 de açúcares redutores, respectivamente. Assim, sugere-se que a enzima fúngica, mesmo em extrato bruto, também poderia ser aplicada em processos biotecnológicos diversos.

A vinhaça é o principal resíduo obtido na produção de álcool, açúcar e aguardente, sendo considerado um efluente de alto poder poluente e fertilizante. Sem o devido tratamento, quando lançada nos rios compromete a sobrevivência de diversos seres aquáticos e quando utilizada como fertilizante, o efluente não tratado pode contaminar lençóis freáticos e afetar os seres terrestres. O objetivo deste trabalho consistiu em avaliar a eficiência e aplicação da fotocatálise heterogênea com TiO2, seguido por um tratamento biológico (lodo ativado) para a redução da carga orgânica do efluente em questão. A caracterização da vinhaça in natura e tratada foi realizada empregando-se métodos estabelecidos e otimizados [DQO, NPOC, DBO5, Análise de Elementos via Absorção Atômica, Fenol, Nitrogênio (orgânico e amoniacal) e Sólidos (ST, STF, STV)]. Por meio de planejamentos fatoriais completos foram determinadas as melhores condições experimentais posterior aos tratamentos fotocatalítico e biológico, tendo como variável resposta a redução de NPOC. Uma caracterização morfológica (DRX, BET e MEV-EDS) da estrutura de TiO2 anatase e rutilo também foi realizada. Após o processo fotocatalítico, a amostra do melhor experimento foi tratada por um processo biológico, a fim de verificar a eficiência de degradação da matéria orgânica do efluente estudado através do sistema híbrido (POA - SLA). Este sistema apresentou maior eficiência tendo como fatores do tratamento fotoquímico 180 minutos de reação, com aeração, pH 9 e efluente in natura; e pH 8 e concentração do lodo de 5 g L-1 no tratamento biológico. A redução de DBO alcançada foi superior a 80 %. / Vinasse is the main residue obtained by the production of alcohol, sugar and blue rum. It is considered a high power pollutant effluent and fertilizer. Untreated vinasse into ponds and rivers make the environment unsafe, especially, to different aquatic species and, when used as a fertilizer, the untreated effluent may contaminate freatic water beds and affect terrestrial species. The aim of this work consists of evaluating the efficiency and application of heterogeneous photocatalysis with TiO2, followed by a biological treatment (activated sludge system) to reduce organic load in the referred effluent. The characterization of vinasse in natura is carried out by the use of established and optimized methods [DQO, NPOC, DBO5, Elemental Analysis by Atomic Absorption, Phenol, Nitrogenium (organic and ammoniacal) and Solids (TS, FTS, VTS)]. Complete factorial designs indicated the best experimental conditions subsequent to photacatalytic and biological treatments providing a reduction of NPOC as a variable response. A morphological evaluation (XRD, B.E.T and SEM-EDS) of anatase and rutile phase of TiO2 structure was also performed. After the photocatalytic process, the sample of the best experiment was treated by a biological process in order to verify the degradation efficiency of the effluent organic matter studied according to the hybrid system (AOP - Activated Sludge System). This system, which presented more efficiency, had a photochemical treatment of 180 minutes carried out in aerated solutions, pH 9 and effluent in natura, while the biological treatment was performed at pH 8 and sludge concentration of 5 g L-1. The reduction of BOD was more than 80%.

Ciências Empresariais (sem parte escolar) / Esta dissertação enquadra-se na problemática da segmentação de mercado e da selecção do número de grupos quando são utilizados modelos mistura de regressão para variáveis normais. Apesar do frequente uso destes modelos, o problema da selecção do número de segmentos continua em aberto, quer na literatura de Marketing, quer Estatística. Determinar o número de segmentos é essencial, na medida em que várias decisões estratégicas de Marketing em mercados heterogéneos dependem dela, existindo custos para as empresas de uma incorrecta definição do número de segmentos de mercado. Esta dissertação possui dois objectivos de investigação: (i) identificação, descrição e organização dos critérios, dispersos na literatura, que podem ser usados na selecção do número de segmentos; (ii) avaliação da eficácia dos critérios revistos e da influência de um conjunto de condições experimentais na selecção do número de segmentos. Os critérios foram classificados em dois grandes grupos, critérios de informação (estimadores da distância Kullback-Leibler, bayesianos e consistentes) e critérios de classificação (índices probabilísticos e índices difusos). A avaliação do desempenho dos 26 critérios seleccionados foi efectuada através de um conjunto de 17 designs experimentais. Na sua concepção deu-se particular relevância ao problema de nichos de mercado e à questão da robustez dos resultados à distribuição de probabilidade assumida (normal versus uniforme). As simulações foram realizadas no programa Gauss 6.0. Os melhores desempenhos foram dos critérios AIC3, AIC4, HQ, ICLBIC e ICOMPLBIC. Na presença de amostras de grande dimensão e um grande número de grupos são igualmente recomendáveis os critérios BIC e CAIC. / This dissertation is developed in the context of market segmentation and market segments retention when mixture regression models for normal data are used. Despite the popularity of these models, the decision of how many segments to keep is an open issue, both in Marketing and Statistics literature. To determine the correct number of market segments is essential, because many strategic Marketing decisions in heterogeneous markets depend on it and an incorrect selection of the number of market segments results in monetary costs for any company. This dissertation has two main objectives: (i) identification, description and classification of the criteria that could be used to select the number of market segments (ii) evaluation of how the reviewed criteria perform and the influence of a set of experimental conditions on the selection of the number of market segments. The reviewed criteria were classified into two groups, namely information criteria (Kullback-Leibler, bayesian and consistent) and classification criteria (probabilistic and fuzzy indices). The performance evaluation of the 26 selected criteria was accomplished through a set of 17 experimental designs. In these experimental designs we considered the problem of market niches and the robustness of the results to the probability assumed (normal versus uniform). The simulations were implemented with Gauss 6.0 package. The best results were obtained for the criteria AIC3, AIC4, HQ, ICLBIC and ICOMPLBIC. BIC and CAIC also perform well with large samples and a large number of market segments.

L’industrie aéronautique travaille sur l’amélioration des systèmes propulsifs parl’introduction de composites dans la fabrication des aubes de soufflante afin d’alléger lastructure et ainsi de réduire la consommation en carburant des avions. Ces pièces réaliséesen tissage 3D présentent généralement des irrégularités de surface. Une manière d’optimisercet aspect est d’ajouter un pli additionnel de surface : nos travaux de thèse portent sur ledéveloppement de ce pli sous la forme d’un renfort « Non Crimp Fabric » (NCF) biaxial extrafinen fibre de carbone de module intermédiaire (IM), inférieur à 100 g/m², régulier et ayant unebonne déformabilité. Lors de nos travaux de thèse, nous avons utilisé la méthode des plans d’expériencepour améliorer la technologie d’étalement afin de répondre aux exigences demandées. Nousavons pu définir la configuration optimale d’étalement permettant d’atteindre la cible d’un pliinférieur à 50 g/m² en fibre de carbone IM. Pour réaliser un NCF extra-fin, après étalement,les plis sont assemblés par couture afin d’assurer la tenue du renfort. La combinaison decouture choisie (armure, tension, longueur, jauge …) conditionne l’aspect du NCF et sacapacité à être manipulée et déformée. Nous avons donc optimisé les paramètres de coutureafin d’obtenir les propriétés souhaitées. Après avoir optimisé l’étalement des fibres et l’assemblage des plis, nous avons réalisé et caractérisé les renforts NCF extra-fins pour valider leurs propriétés. Nous sommesfinalement parvenus à mettre au point un renfort NCF en fibre de carbone IM, inférieur à50 g/m² par pli ayant un taux de couverture supérieur à 98 % et une bonne capacité à sedéformer. / Aircraft manufacturers are working on the improvement of their engines bymanufacturing fan blades with advanced composite materials to reduce fuel consumption.However, fan blades are made from 3D woven fabrics which often have surface irregularities.It can be minimized by an additional thin layer on the surface : our thesis work is focused onthe development of a new textile structure based on ultra-thin biaxial “Non Crimp Fabric” (NCF)technology. This spread NCF made from intermediate modulus (IM) carbon fibers must belighter than 100 gsm, regular and deformable.During our thesis work, we used Design of Experiments (DOE) methodology to improvethe spreading technology used by Chomarat to make ultra-light NCF materials and meet theestablished requirements. We were able to reach the ultra-thin ply target of less than 50 gsmper ply. After optimizing the spreading process these thin ply tapes are stitched together tocreate NCF. Stability, visual aspect, handling and deformability are dependent on the stitchingsettings (stitching pattern, tension, length, gauge, etc.). Therefore we optimized the stitchingparameters to get the desired properties.After the spreading and stitching process had been optimized, the NCF weremanufactured and tested to validate the desired properties had been achieved. The testingconfirmed that we were able to develop a new carbon fiber NCF that was less than 50 gsm perply, had a coverage rate of higher than 98 % and had good deformability characteristics.

<p>This thesis describes the application of multivariate methods in a novel approach to the formulation of tablets for direct compression. It begins with a brief historical review, followed by a basic introduction to key aspects of tablet formulation and multivariate data analysis. The bulk of the thesis is concerned with the novel approach, in which excipients were characterised in terms of multiple physical or (in most cases) spectral variables. By applying Principal Component Analysis (PCA) the descriptive variables are summarized into a few latent variables, usually termed scores or principal properties (PP’s). In this way the number of descriptive variables is dramatically reduced and the excipients are described by orthogonal continuous variables. This means that the PP’s can be used as ordinary variables in a statistical experimental design. The combination of latent variables and experimental design is termed multivariate design or experimental design in PP’s. Using multivariate design many excipients can be included in screening experiments with relatively few experiments.</p><p>The outcome of experiments designed to evaluate the effects of differences in excipient composition of formulations for direct compression is, of course, tablets with various properties. Once these properties, e.g. disintegration time and tensile strength, have been determined with standardised tests, quantitative relationships between descriptive variables and tablet properties can be established using Partial Least Squares Projections to Latent Structures (PLS) analysis. The obtained models can then be used for different purposes, depending on the objective of the research, such as evaluating the influence of the constituents of the formulation or optimisation of a certain tablet property.</p><p>Several examples of applications of the described methods are presented. Except in the first study, in which the feasibility of this approach was first tested, the disintegration time of the tablets has been studied more carefully than other responses. Additional experiments have been performed in order to obtain a specific disintegration time. Studies of mixtures of excipients with the same primary function have also been performed to obtain certain PP’s. Such mixture experiments also provide a straightforward approach to additional experiments where an interesting area of the PP space can be studied in more detail. The robustness of a formulation with respect to normal batch-to-batch variability has also been studied.</p><p>The presented approach to tablet formulation offers several interesting alternatives, for both planning and evaluating experiments.</p>

<p>New techniques and approaches for organic synthesis, purification and biological testing are enabling pharmaceutical industries to produce and test increasing numbers of compounds every year. Surprisingly, this has not led to more new drugs reaching the market, prompting two questions – why is there not a better correlation between their efforts and output, and can it be improved? One possible way to make the drug discovery process more efficient is to ensure, at an early stage, that the tested compounds are diverse, representative and of high quality. In addition the biological evaluation systems have to be relevant and reliable. The diversity of the tested compounds could be ensured and the reliability of the biological assays improved by using Design Of Experiments (DOE) more frequently and effectively. However, DOE currently offers insufficient options for these purposes, so there is a need for new, tailor-made DOE strategies. The aim of the work underlying this thesis was to develop and evaluate DOE approaches for diverse compound selection and efficient assay optimisation. This resulted in the publication of two new DOE strategies; D-optimal Onion Design (DOOD) and Rectangular Experimental Designs for Multi-Unit Platforms (RED-MUP), both of which are extensions to established experimental designs.</p><p>D-Optimal Onion Design (DOOD) is an extension to D-optimal design. The set of possible objects that could be selected is divided into layers and D-optimal selection is applied to each layer. DOOD enables model-based, but not model-dependent, selections in discrete spaces to be made, since the selections are not only based on the D-optimality criterion, but are also biased by the experimenter’s prior knowledge and specific needs. Hence, DOOD selections provide controlled diversity.</p><p>Assay development and optimisation can be a major bottleneck restricting the progress of a project. Although DOE is a recognised tool for optimising experimental systems, there has been widespread unwillingness to use it for assay optimisation, mostly because of the difficulties involved in performing experiments according to designs in 96-, 384- and 1536- well formats. The RED-MUP framework combines classical experimental designs orthogonally onto rectangular experimental platforms, which facilitates the execution of DOE on these platforms and hence provides an efficient tool for assay optimisation.</p><p>In combination, these two strategies can help uncovering the crossroads between biology and chemistry in drug discovery as well as lead to higher information content in the data received from biological evaluations, providing essential information for well-grounded decisions as to the future of the project. These two strategies can also help researchers identify the best routes to take at the crossroads linking biological and chemical elements of drug discovery programs.</p>

<p>Statistical experimental designs have been used for method development and optimisation of separation. Two reversed phase HPLC methods were optimised. Parameters such as the pH, the amount of tetrabutylammonium (TBA; co-ion) and the gradient slope (acetonitrile) were investigated and optimised for separation of erythromycin A and eight related compounds. In the second method, a statistical experimental design was used, where the amounts of acetonitrile and octane sulphonate (OSA; counter ion) and the buffer concentration were studied, and generation of an α-plot with chromatogram simulations optimised the separation of six analytes.</p><p>The partial filling technique was used in capillary electrophoresis to introduce the chiral selector Cel7A. The effect of the pH, the ionic strength and the amount of acetonitrile on the separation and the peak shape of R- and S-propranolol were investigated.</p><p>Microemulsion electrokinetic chromatography (MEEKC) is a technique similar to micellar electrokinetic chromatography (MEKC), except that the microemulsion has a core of tiny droplets of oil inside the micelles. A large number of factors can be varied when using this technique. A screening design using the amounts of sodium dodecyl sulphate (SDS), Brij 35, 1-butanol and 2-propanol, the buffer concentration and the temperature as factors revealed that the amounts of SDS and 2-propanol were the most important factors for migration time and selectivity manipulation of eight different compounds varying in charge and hydrophobicity. SDS and 2-propanol in the MEEKC method were further investigated in a three-level full factorial design analysing 29 different compounds sorted into five different groups. Different optimisation strategies were evaluated such as generating response surface plots of the selectivity/resolution of the most critical pair of peaks, employing chromatographic functions, simplex optimisation in MODDE and 3D resolution maps in DryLab™.</p><p>Molecular descriptors were fitted in a PLS model to retention data from the three-level full factorial design of the MEEKC system. Two different test sets were used to study the predictive ability of the training set. It was concluded that 86 – 89% of the retention data could be predicted correctly for new molecules (80 – 120% of the experimental values) with different settings of SDS and 2-propanol.</p><p>Statistical experimental designs and chemometrics are valuable tools for the development and optimisation of analytical methods. The same chemometric strategies can be employed for all types of separation techniques.</p>

Statistical experimental designs have been used for method development and optimisation of separation. Two reversed phase HPLC methods were optimised. Parameters such as the pH, the amount of tetrabutylammonium (TBA; co-ion) and the gradient slope (acetonitrile) were investigated and optimised for separation of erythromycin A and eight related compounds. In the second method, a statistical experimental design was used, where the amounts of acetonitrile and octane sulphonate (OSA; counter ion) and the buffer concentration were studied, and generation of an α-plot with chromatogram simulations optimised the separation of six analytes. The partial filling technique was used in capillary electrophoresis to introduce the chiral selector Cel7A. The effect of the pH, the ionic strength and the amount of acetonitrile on the separation and the peak shape of R- and S-propranolol were investigated. Microemulsion electrokinetic chromatography (MEEKC) is a technique similar to micellar electrokinetic chromatography (MEKC), except that the microemulsion has a core of tiny droplets of oil inside the micelles. A large number of factors can be varied when using this technique. A screening design using the amounts of sodium dodecyl sulphate (SDS), Brij 35, 1-butanol and 2-propanol, the buffer concentration and the temperature as factors revealed that the amounts of SDS and 2-propanol were the most important factors for migration time and selectivity manipulation of eight different compounds varying in charge and hydrophobicity. SDS and 2-propanol in the MEEKC method were further investigated in a three-level full factorial design analysing 29 different compounds sorted into five different groups. Different optimisation strategies were evaluated such as generating response surface plots of the selectivity/resolution of the most critical pair of peaks, employing chromatographic functions, simplex optimisation in MODDE and 3D resolution maps in DryLab™. Molecular descriptors were fitted in a PLS model to retention data from the three-level full factorial design of the MEEKC system. Two different test sets were used to study the predictive ability of the training set. It was concluded that 86 – 89% of the retention data could be predicted correctly for new molecules (80 – 120% of the experimental values) with different settings of SDS and 2-propanol. Statistical experimental designs and chemometrics are valuable tools for the development and optimisation of analytical methods. The same chemometric strategies can be employed for all types of separation techniques.

During the last few decades, concerns about water shortages and pollution have increased. Consequently, environmental legislations and regulations for wastewater discharge have been issued. The objective of this work was to contribute in developing an efficient dsorbent for removing heavy metal ions from wastewater. The thesis focused on evaluating amine-modified SBA-15 as copper and other heavy metal ions adsorbent, by determining a variety of adsorptive properties with the aim of gaining a deep understanding of its behavior and to outline its advantages and limitations. The influence of synthesis conditions on the mesostructural stability of the resultant materials after different water treatments was systematically investigated. N2 adsorption results indicated that the material prepared via co-condensation and aged at 100 ºC was not stable and lost its ordered mesoporous structure after contacting water even at room temperature. Aging at 130 ºC and addition of inorganic salts resulted in materials that maintained their mesporous structure under different water treatments. The material synthesized in the presence of KCl was used as adsorbent for the rest of the thesis work. It was shown that the structural collapse observed in amine-modified SBA-15 prepared by conventional method when contacted with aqueous solutions is associated with the drying process, and not the treatment itself. This structural collapse was avoided by replacing water with more volatile liquids such as acetone, before drying. Amino-functionalized SBA-15 was tested for the removal of copper ions from aqueous solutions under different temperatures, pH, initial concentrations and agitation speeds. The obtained results indicated that the amino-functionalized SBA-15 was very efficient and equilibrium was achieved in less than 30 min at room temperature. The adsorption capacity increased dramatically with increasing temperature, initial copper concentration and pH. Under suitable conditions, the material exhibited high adsorption capacity even at very low copper concentration. To further investigate the effect of dsorption parameters, a 24 factorial design experiments were used to screen the factors affecting the copper removal efficiency. All the parameters main effects were significant within a 95 % confidence level. Surface composite design was used to develop a reliable model representing the adsorption process. The statistical tests used proved the adequacy of the second order model. Optimization of the factors levels was carried out and the recommended optimum conditions are: copper concentration of 20 mg/L, adsorbent/solution ratio of 1.57 g/L, pH of 6.5, and T = 294 K with 95% copper removal. The effect of regeneration conditions was investigated after three adsorption–desorption cycles, under different batchwise regeneration conditions. Using a composite surface design methodology, the effect of the regeneration conditions on the performance of the adsorbent was investigated. It was found that all the studied parameters have a statistically significant influence on the working dsorption capacity. With respect to structural properties and amine content, none of the factors was found to be significant. Regeneration using EDTA was found to be more efficient than acid treatment. Amino-functionalized SBA-15 was studied as potential absorbent for Cd2 +, Co2 +, Cu2 +, Zn2 +, Pb2 +, Ni2 +, Al3+ and Cr3 +. The adsorption capacity and selectivity of the material were investigated in single and multi-metal solutions. Using very dilute solutions, i.e., 10 ppm, more than 95% of cations were removed, except for Co2+ and Cr3 +, indicatingthe high sensitivity of the current adsorbent. The adsorption capacities in multi-metal solutions were lower than in single-metal ones because of competition between metallic elements for the amine groups. The adsorbent was not affected in the presence of sodium, potassium, and calcium, indicating that the ionic strength does not affect the adsorption properties. Application of this material to remove copper in tap water, river water, and electroplating wastewater was shown to be successful. Dynamic experiments were carried out on the adsorption of copper ions in a laboratory packed-bed of amine-modified SBA-15. Breakthrough curves were analyzed at different flowrates and after two adsorption-desorption cycles. Furthermore, a model based on mass balance was developed and tested for predicting the breakthrough curves under different experimental conditions used. The results suggested that the developed model was in good agreement with the experimental data. Bed regeneration was performed by circulating 0.2 M EDTA solution through the column for 30 min. Résumé Durant les quelques dernières décennies, les préoccupations concernant les pénuries d'eau et la pollution en général ont augmenté. Par conséquent, des législations et des réglementations environnementales pour les rejets d'eaux usées ont été introduites. L'objectif de ce travail était de contribuer au développement d'un adsorbant efficace pour éliminer les ions de métaux lourds des eaux usées. Cette thèse porte sur l'évaluation de SBA-15 modifiée avec des amines comme adsorbant pour le cuivre et d'autres ions de métaux lourds par la détermination d'une multitude de propriétés d'adsorption dans le but d'acquérir une profonde compréhension de son comportement et d’identifier ses avantages et ses limites. L'influence des conditions de synthèse sur la stabilité des matériaux mésoporeux obtenus après différents traitements a été étudié de façon systématique. Les résultats d'adsorption de N2 ont indiqué que le matériel préparé par co-condensation et vieilli à 100 °C n'était pas stable et a perdu sa structure mésoporeuse ordonnée après avoir été en contact avec l'eau même à température ambiante. Le vieillissement à 130 °C, avec ajout de sels inorganiques, a abouti à des matériaux qui ont maintenu leur structure mésoporeuse sous différents traitements en présence d'eau. Le matériau synthétisé en présence de KCl a été utilisé comme adsorbant pour le reste du travail de cette thèse. Il a été démontré que l'effondrement de la structure observé dans la SBA-15 modifiée aux amines, préparée par la méthode conventionnelle en contact avec des solutions aqueuses est associé avec le processus de séchage, et non le traitement lui-même. Cet effondrement de structure a été évité en remplaçant l'eau avec des liquides plus volatils tels que l'acétone, avant le séchage. La SBA-15 amino-fonctionnalisée a été testée pour l'élimination des ions de cuivre des solutions aqueuses à différentes températures, pH, concentrations initiales et vitesses d'agitation. Les résultats obtenus ont indiqué que la SBA-15 amino-fonctionnalisée était très efficace et l'équilibre a été atteint en moins de 30 min à température ambiante. La capacité d'adsorption a considérablement augmenté avec la température, la concentration initiale de cuivre et le pH. Sous des conditions appropriées, le matériau a manifesté une grande capacité d'adsorption, même à des concentrations très faibles en cuivre. Afin d’étudier l'effet des paramètres d'adsorption, un plan factoriel de 24 expériences a été utilisé pour dépister les facteurs affectant l'efficacité d'élimination du cuivre. Tous les effets principaux des paramètres étaient importants à 95% de niveau de confiance. La méthodologie de la surface composite a été utilisée pour développer un modèle fiable qui représente le processus d'adsorption. Les tests statistiques utilisés ont prouvé la pertinence du modèle de second ordre. L’optimisation des niveaux des facteurs a été effectuée et les conditions optimales recommandées sont: la concentration en cuivre de 20 mg/L, le rapport adsorbant/solution de 1.57 g/L, pH de 6.5 et T = 294 K pour l'élimination de 95% de cuivre. L'effet des conditions de régénération a été étudié après trois cycles d'adsorption-désorption, sous différentes conditions de régénération. En utilisant la méthodologie de la surface composite, l'effet des conditions de régénération sur la performance de l'adsorbant a été étudié. Il a été constaté que tous les paramètres étudiés ont une influence statistiquement significative sur la capacité de travail d'adsorption. En ce qui concerne les propriétés structurelles et la teneur en amine, aucun des facteurs n’a été jugé significatif. La régénération à l'aide d'EDTA a été jugée plus efficace que le traitement acide. La SBA-15 amino-fonctionnalisée a été étudiée comme absorbant potentiel de Cd2+, Co2+, Cu2+, Zn2+, Pb2+, Ni2+, Al3+ and Cr3+. La capacité d'adsorption et la sélectivité du matériau ont été étudiées dans des solutions mono- et multi-métalliques. En utilisant des solutions très diluées, soit 10 ppm, plus de 95% de cations ont été enlevés, sauf pour le Co2+ et Cr3+, indiquant la forte sensibilité de l'adsorbant. Les capacités d'adsorption dans les solutions multi-métalliques étaient inférieures à celles des solutions mono-métalliques en raison de la concurrence entre les éléments métalliques pour les groupes amine. L'adsorbant n'a pas été affecté par la présence de sodium, de potassium et de calcium, ce qui indique que la force ionique n'affecte pas les propriétés d'adsorption. L’usage avec succès de ce matériau pour éliminer le cuivre dans l'eau de robinet, l’eau de rivière et les eaux usées de galvanoplastie a été démontré. Des expériences dynamiques ont été réalisées sur l'adsorption des ions de cuivre par la SBA-15 amine-modifiée sur une colonne à lit fixe de laboratoire. Les courbes de perçage ont été analysées à des débits différents et après deux cycles d'adsorption-désorption. De plus, un modèle basé sur le bilan de matière a été développé et testé pour prédire les courbes de perçage sous les différentes conditions expérimentales utilisées. Les résultats suggèrent que le modèle développé est en bon accord avec les données expérimentales. La régénération du lit a été réalisée en faisant circuler une solution EDTA à 0.2 M à travers la colonne pendant 30 min.