Waste oil generated from industrial operations at a diesel locomotive maintenance facility was investigated to establish its treatability and potential volume reduction. The waste oil and water mixture separated into four distinct layers; free oil, emulsified oil, weathered oil, and wastewater. The research was conducted in a series of three batch experiments and focused on the emulsified and weathered oils. The waste oil was aerobically treated in nutrient amended, 55 gallon (208 L) drums for 38 to 42 days in 10 and 20 % mixtures with sufficient air for mixing and oxygen. Biodegradation, and the role of a synthetic surfactant in promoting biodegradation, was measured using chemical oxygen demand (COD), fluorescein diacetate (FDA), and gas chromatography (GC) analyses with extractable material. Dewatering of biodegraded oil was measured using capillary suction test (CST), time to filter (TTF), and percent cake solids. Batch 1 examined the role of bioaugmentation by comparing a 10% waste oil mixture that was augmented with a mixture of hydrocarbon degraders to a 10 % mixture of waste oil with no bioaugmentation. Final COD reductions were 59 (± 9) and 38 (±3) % for the bioaugmented and non-bioaugmented reactors, respectively. Chromatographs showed significant reduction in the abundance of peaks by the end of the experiment for both reactors. Overall results suggested that there was no significant difference in biodegradation capabilities between the amended and native microorganisms. Batch 2 was conducted to determine if a synthetic surfactant (Tween-80) could enhance biodegradation of a 10 % waste oil mixture. The surfactant-amended reactor showed COD reduction 3 days before the non-surfactant-amended reactor. Chromatographs showed similar results for both reactors with the non-surfactant-amended reactor showing slightly better degradation by the end of the experiment. The total COD reduction by the end of the experiment was the same in both (R1: 85 ± 20%, R2: 84 ± 16 %), suggesting that exogenous surfactant addition did not have a long-term impact in the biodegradation of the waste oil. Batch 3 examined the effect of different oil phases and concentrations on biodegradation and the dewatering characteristics of post-biodegraded waste oil. The 20 % weathered and emulsified waste oil mixture showed a clear delay in COD reduction (no notable reduction until day 24) compared to the 10 % weathered waste oil mixture. The final COD reductions were the same (R1: 48 ± 13%, R2: 49, ± 23 %). Chromatographs showed similar results for both reactors and indicated that degradation of the waste oil occurred in both reactors. The data suggest that the 20 % waste oil mixture can be degraded to the same extent as the 10 % mixture in 38 days. Dewatering characteristics, as measured by CST, were poor for the 20 % post-biodegraded combined waste oil mixture without conditioning. Conditioning with alum or ferric chloride substantially improved dewatering of the waste oil for the 20 % mixture but was of limited benefit for the 10 % mixture. Percent cake solids for conditioned 10 % post-biodegraded waste oil mixture was 44 (± 0.3) to 50 (± 1.7) % and 34 (± 0.3) to 50 (± 1.8) % for the 20 % mixture. The cake solids for the unconditioned 10 % mixture was 50 to 65 % and 54 to 68 % for the 20 % mixture. The higher percent cake solids for the unconditioned 20 % mixture was countered by the very high TTF (up to 30 min. to filter 50 mL) and the inability to dewater the sludge during the last five sampling events. Conditioning appeared to have a limited effect on the dewatering properties of the 10 % mixture. / Master of Science

Yes / The structure and dynamics of a single molecule of the nonionic surfactant polysorbate 80 (POE (20) sorbitan monooleate; Tween 80 ) as well as a micelle of polysorbate 80 in water have been investigated by molecular dynamics simulation. In its free state in water the polysorbate 80 molecule samples almost its entire conformational space. The micelle structure is compact and exhibits a prolate ellipsoid shape, with the surface being dominated by the polar terminal groups of the POE chains. The radius of gyration of the micelle was 26.2 A. The physical radius, determined from both the radius of gyration and atomic density, was about 35 A. The estimated diffusion constants for the free molecule (1.8 10 6 cm2 s 1) and the micelle (1.8 10 7 cm2 s 1) were found to be remarkably close to the respective experimental values. The lateral diffusion of the molecules on the micelle surface was estimated to be 1.7 10 7 cm2 s 1, which confirms the highly dynamic nature of the micelle structure. / Tehran University of Medical Sciences & Health Services

Made available in DSpace on 2014-12-17T15:42:05Z (GMT). No. of bitstreams: 1 CiroJFR_DISSERT.pdf: 5688343 bytes, checksum: f082f764a617b016bd522ef00e0f6125 (MD5) Previous issue date: 2012-08-30 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Nowadays, the use of chemicals that satisfactorily meet the needs of different sectors of the chemical industry is linked to the consumption of biodegradable materials. In this context, this work contemplated biotechnological aspects with the objective of developing a more environmentally-friendly corrosion inhibitor. In order to achieve this goal, nanoemulsion-type systems (NE) were obtained by varying the amount of Tween 80 (9 to 85 ppm) a sortitan surfactant named polyoxyethylene (20) monooleate. This NE-system was analyzed using phase diagrams in which the percentage of the oil phase (commercial soybean oil, codenamed as OS) was kept constant. By changing the amount of Tween 80, several polar NE-OS derived systems (O/W-type nanoemulsion) were obtained and characterized through light scattering, conductivity and pH, and further subjected to electrochemical studies. The interfacial behavior of these NE-OS derived systems (codenamed NE-OS1, S2, S3, S4 and S5) as corrosion inhibitors on carbon steel AISI 1020 in saline media (NaCl 3.5%) were evaluated by measurement of Open Circuit Potential (OCP), Polarization Curves (Tafel extrapolation method) and Electrochemical Impedance Spectroscopy (EIS). The analyzed NE-OS1 and NE-OS2 systems were found to be mixed inhibitors with quantitative efficacy (98.6% - 99.7%) for concentrations of Tween 80 ranging between 9 and 85 ppm. According to the EIS technique, maximum corrosion efficiency was observed for some tested NE-OS samples. Additionaly to the electrochemical studies, Analysis of Variance (ANOVA) and Principal Component Analysis (PCA) were used, characterization of the nanoemulsion tested systems and adsorption studies, respectively, which confirmed the results observed in the experimental analyses using diluted NE-OS samples in lower concentrations of Tween 80 (0.5 1.75 ppm) / Atualmente, a utiliza??o de produtos qu?micos que atendam satisfatoriamente as necessidades de diferentes setores da ind?stria qu?mica encontra-se vinculada ao consumo de materiais biodegrad?veis. Neste contexto, o presente trabalho foi desenvolvido contemplando aspectos biotecnol?gicos com o objetivo de se desenvolver um inibidor de corros?o menos agressivo ao meio ambiente. Para tanto, uma nanoemuls?o (denominada de NE-OS) foi obtida com Tween 80 (polioxietileno (20) monooleato), ?leo de soja (OS) e ?gua bidestilada. A modifica??o dos percentuais deste tensoativo sorbitano (entre 9 e 85 ppm) foi avaliada em diagramas de fases em que se manteve constante o percentual da fase ?leo, possibilitando a forma??o do sistema NE-OS em diferentes concentra??es. Desta forma, nanoemuls?es (NE-OS1, S2, S3, S4 e S5) polares (do tipo O/A) foram caracterizadas (an?lise de dispers?o de luz, condutividade e pH) e submetidas a estudos eletroqu?micos. O comportamento interfacial destes sistemas nanoemulsionados como inibidores de corros?o na presen?a de a?o-carbono AISI 1020, em meio salino (NaCl 3,5%) foi avaliado pela determina??o do Potencial de Circuito Aberto (OCP), Curvas de Polariza??o (obtidas pela extrapola??o das curvas de Tafel) e Espectroscopia de Imped?ncia Eletroqu?mica (EIE). De acordo com os resultados obtidos pelas an?lises das Curvas de Polariza??o, foi poss?vel caracterizar o sistema NE-OS (e suas varia??es) como inibidores mistos com efici?ncias m?ximas de inibi??es quantitativas (98,6% - 99,7%) para NE-OS1 e NE-OS2 (9 - 85 ppm do tensoativo). No entanto, de acordo com a t?cnica EIE, as efici?ncias m?ximas de inibi??es quantitativas foram observadas para v?rias amostras deste sistema NE-OS. Como ferramentas adicionais aos estudos eletroqu?micos foram realizados quimiom?tricos de An?lise de Vari?ncia (ANOVA) e An?lise de Componentes Principais (PCA), utilizadas, respectivamente, para caracteriza??o das nanoemuls?es e estudo de isotermas de adsor??o, que confirmaram os resultados observados nas investiga??es experimentais em que se utilizaram as nanoemuls?es dilu?das com o tensoativo em concentra??es reduzidas (0,5 1,75 ppm)

The severe effects associated with global warming and the rapid increase in oil prices are the driving forces behind the demand for clean carbon–neutral and biofuels such as bioethanol. Research studies are now focusing on using lignocellulosic biomass for bioethanol production due to concerns about food security and inflation. The chosen feedstock for this study was maize stover, given that it is the most abundant agricultural residue in South Africa. Maize stover consists of structural carbohydrates that can be enzymatically converted into fermentable sugars. The major drawback in the production of bioethanol from lignocellulosic biomass has been its high equipment and operational costs due to the use of acids and high enzyme loadings. The aim of this study was to investigate the possibility of optimizing the enzyme hydrolysis of pre–treated maize stover without further increasing the amount of enzymes. The maximum glucose yield attained was 690 ± 35 mg of glucose per gram of substrate which is equivalent to a conversion efficiency of 119%. The preferred pre–treatment method used was 3% sulphuric acid for 60 minutes at 121oC and the enzymatic hydrolysis process was performed at a 5% substrate loading, 50oC and pH 5.0 using 30 FPU per gram of cellulose in the presence of 1.25 g.L–1 of Tween 80 for 48 hours. The addition of Tween 80 increased the glucose yields by 23 % and thus, it has the potential of lowering the overall process costs by increasing the glucose yield without further addition of enzymes. Keywords: Bioethanol, maize stover, lignocellulosic biomass, pre–treatment, enzymatic hydrolysis / Thesis (M.Sc. Engineering Sciences (Chemical Engineering))--North-West University, Potchefstroom Campus, 2011.

The severe effects associated with global warming and the rapid increase in oil prices are the driving forces behind the demand for clean carbon–neutral and biofuels such as bioethanol. Research studies are now focusing on using lignocellulosic biomass for bioethanol production due to concerns about food security and inflation. The chosen feedstock for this study was maize stover, given that it is the most abundant agricultural residue in South Africa. Maize stover consists of structural carbohydrates that can be enzymatically converted into fermentable sugars. The major drawback in the production of bioethanol from lignocellulosic biomass has been its high equipment and operational costs due to the use of acids and high enzyme loadings. The aim of this study was to investigate the possibility of optimizing the enzyme hydrolysis of pre–treated maize stover without further increasing the amount of enzymes. The maximum glucose yield attained was 690 ± 35 mg of glucose per gram of substrate which is equivalent to a conversion efficiency of 119%. The preferred pre–treatment method used was 3% sulphuric acid for 60 minutes at 121oC and the enzymatic hydrolysis process was performed at a 5% substrate loading, 50oC and pH 5.0 using 30 FPU per gram of cellulose in the presence of 1.25 g.L–1 of Tween 80 for 48 hours. The addition of Tween 80 increased the glucose yields by 23 % and thus, it has the potential of lowering the overall process costs by increasing the glucose yield without further addition of enzymes. Keywords: Bioethanol, maize stover, lignocellulosic biomass, pre–treatment, enzymatic hydrolysis / Thesis (M.Sc. Engineering Sciences (Chemical Engineering))--North-West University, Potchefstroom Campus, 2011.

Orientador: Carlos Raimundo Ferreira Grosso / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-05T16:31:42Z (GMT). No. of bitstreams: 1 Davanco_Taciana_M.pdf: 2629355 bytes, checksum: cdbb1966776fdc55926071d8c776dbb4 (MD5) Previous issue date: 2006 / Resumo: Desenvolvimento de biofilmes tem crescido devido a possibilidade de substituição parcial de materiais plásticos não degradáveis. Proteínas e polissacarídeos têm sido utilizados para a produção de filmes com boas propriedades mecânicas. Porém filmes a partir desses materiais apresentam alta permeabilidade ao vapor de água. Uma alternativa usada para diminuir a permeabilidade ao vapor de água dos filmes é a incorporação de substancias hidrofóbicas na composição da solução filmogênica, porém a incorporação dessas substâncias na matriz filmogênica não ocorre de maneira homogênea. Com o objetivo de melhorar a incorporação das substâncias hidrofóbicas na matriz protéica do filme foram adicionados os surfactantes (SDS e Tween 80), que são compostos orgânicos constituídos por moléculas anfifílicas, contendo uma parte polar e outra apolar, com o intuito desta substância interagir na proteína e no ácido graxo, tornando a matriz filmogênica menos heterogênea. O efeito do pH também foi estudado, com a finalidade de observar se este exerce influência na homogeneidade da matriz filmogênica. Os ácidos graxos utilizados no trabalho foram o ácido capróico (6C), e o ácido esteárico (18C), com o objetivo de avaliar e comparar se o número de carbonos da cadeia do ácido graxo exerce influencia na incorporação da matriz protéica. Os filmes foram caracterizados quanto as propriedades de barreira ao vapor de água e propriedades mecânicas, solubilidade em água, opacidade, isotermas de sorção e calorimetria diferencial de varredura, podendo ser observado que a adição dos surfactantes melhorou a barreira ao vapor de água e diminuiu a resistência à tração dos filmes, não sendo observado diferenças na cor e opacidade dos filmes . Posteriormente foram analisadas as características morfológicas, através da microscopia ótica, microscopia eletrônica de varredura e microscopia confocal de varredura a laser, observando que o ajuste do pH e a adição do surfactante modificam a estrutura morfológica do filme / Abstract: Development of biofilms has grown considering the possibility of partial substitution of plastic materials not degradable. Proteins and polysaccharides have been used for the production of films with good mechanical properties. However films produced with these materials present high water vapor permeability to the water vapor. An used alternative to improve the water vapor barrier of the films is the incorporation of hydrophobic substances in the composition of the filmogenic solution, however the incorporation of these substances in the filmogenic matrix does not occur in homogeneous way. Thus with, the objective to improve the incorporation of hydrofhobic substances in the protein matrix of the film surfactants had been added (SDS and Tween 80). They are organic compounds constituted by anphiphilics molecules, incluing a polar part and other apolar, with the intention that is substances improve the interaction between the protein and the fats acids, producing a less heterogeneous filmogenic matrix. The effect of pH also was studied, with the purpose to observe if this produce influence in the homogeneity of the filmogenic matrix. The fats acids used in this work were the caproic acid (6C), and the stearic acid (18C), with the objective to evaluate and to compare if the carbon number of the fats acids exerts influences in the incorporation on the protein matrix. The films were characterized with respect to the properties of barrier to the water vapor, solubility in water, opacity, isotherms of sorption and thermal properties, being able to be observed that the addition of the surfactants improved the water vapor permeability and decreased the tensile strenght of the films, not being observed differences in the color and opacity of the films. Later the morphologic characteristics had been analyzed, through optics microscopy, scanning electron microscopy and confocal laser scanning microscopy, observing that the adjustment of pH and the addition of the surfactant modify the morphological structure of the films / Mestrado / Nutrição Experimental e Aplicada à Tecnologia de Alimentos / Mestre em Alimentos e Nutrição

Micelles (MIs) and microemulsions (MEs) are classified as stabilized systems by surfactants and are very similar with respect to their structure and physico-chemical properties. As for the applicability, they have been deployed by being able to carry drugs which have a limited systemic bioavailability by oral route. The formation of these systems is mainly dependent on the types of components used, making it important to study its influence on the structure. The goal of this study was to obtain and characterize micellar and microemulsion systems (containing essential oil of Citrus sinensis (L.) Osbeck as oil phase) stabilized by a nonionic surfactant (Tween 80) and short-chain cosurfactant (alcohol ethyl) which may be used as a delivery system for nifedipine (NFD a model drug) seeking to verify the influence of the phases and the interaction of the drug in the structure of these systems. Ternary and pseudoternary phase diagrams for MIs and MEs, respectively, and were obtained from the formation regions, formulations were selected for physico-chemical characterization and incorporation of NFD. The macro and microscopic aspects were evaluated using polarized light microscopy (MLP), measures pH, electrical conductivity and surface tension. The average droplet size was measured by dynamic light scattering (DLS) and small angle x-ray scattering (SAXS). The results demonstrated that such systems are stable, optically isotropic and transparent in the absence and presence of drug. The droplet size decreases with increasing amount of surfactant to MIs and the mixture surfactant/cosurfactant to the MEs. The influence of the cosurfactant in MIs was negligible. The increase of the amount of oily phase in MEs caused an increase in the droplet size. The presence of NFD no influence on the structure of MIs, but for the MEs increased droplet size, suggesting that the NFD is the internal phase of the MEs. The modeling by SAXS curves for MIs and MEs most diluted were made and showed the interaction between the NFD and systems, confirming the previous results. Studies by Fourier Transformed Infra Red (FTIR) confirmed the interaction between MIs and MEs with the stratum corneum (EC) , which allows the use of these systems as permeation enhancers of NFD. / As micelas (MIs) e as microemulsões (MEs) são classificadas como sistemas estabilizados por tensoativos e se assemelham bastante com relação a sua estrutura e propriedades físico-químicas. Quanto a sua aplicabilidade, elas têm sido destacadas por serem capazes de veicular fármacos que possuem uma biodisponibilidade sistêmica limitada por via oral. A formação destes sistemas é dependente principalmente dos tipos de componentes utilizados, tornando-se relevante o estudo da sua influência na estrutura. O objetivo do presente trabalho foi a obtenção e caracterização de sistemas micelares e microemulsionados (contendo óleo essencial de Citrus sinensis (L.) Osbeck como fase oleosa), estabilizados por um tensoativo não iônico (Tween 80) e um cotensoativo de cadeia curta (álcool etílico), que possam ser utilizados como sistema de liberação para a nifedipina (NFD, um fármaco modelo), buscando verificar a influência das fases e a interação do fármaco na estrutura desses sistemas. Diagramas de fase ternário e pseudoternário para MIs e MEs, respectivamente, foram obtidos e a partir das regiões de formação, formulações foram selecionadas para caracterização físico-química e incorporação da NFD. Os aspectos macro e microscópicos foram avaliados utilizando microscopia de luz polarizada (MLP), medidas de pH, condutividade elétrica e tensão superficial. O tamanho médio de gotículas foi avaliado por espalhamento dinâmico de luz (DLS) e espalhamento de raios-x a baixos ângulos (SAXS). Os resultados demonstraram que esses sistemas são estáveis, isotrópicos e opticamente transparentes na ausência e presença de fármaco. O tamanho das gotículas diminuiu com o aumento da quantidade de tensoativo para as MIs e de mistura de tensoativo/cotensoativo para as MEs. A influência do cotensoativo nas MIs foi praticamente desprezível. O aumento da quantidade de fase oleosa nas MEs ocasionou um aumento do tamanho das gotículas. A presença da NFD não exerceu influência na estrutura das MIs, entretanto para as MEs aumentou o tamanho de gotículas, sugerindo que a NFD se encontra na fase interna das MEs. Os modelamentos das curvas de SAXS para as MIs e MEs mais diluídas foram realizados e mostraram a interação existente entre a NFD e os sistemas, corroborando com os resultados anteriores. Estudos por espectrofotometria de absorção na região do infravermelho com transformada de Fourier (FTIR) comprovaram a interação das MIs e das MEs com o estrato córneo (EC), o que possibilita o uso destes sistemas como promotores de permeação da NFD.