Produced water is one of the major by products of oil and gas exploitation which is produced in large amounts up to 80% of the waste stream. Oil and grease concentration in produced water is the key parameter that is used for compliance monitoring, because it is easy to measure. For Canadian offshore operations, the current standard is a 30-day volume weighted average oil-in-water concentration in discharged produced water not exceeding 30 mg/L. Treatment of produced water may therefore be required in order to meet pre-disposal regulatory limits. The measurement of oil in produced water is important for both process control and reporting to regulatory authorities. Without the specification of a method, reported concentrations of oil in produced water can mean little, as there are many techniques and methods available for making this measurement, but not all are suitable in a specific application. The first part of this study focused on selecting a suitable analytical method for oil and grease measurement in oil field produced water. Petroleum ether was found to offer a comparative dissolution of crude oil as dichloromethane and hexane; it was therefore used as the solvent of choice for the UV-Vis spectrophotometric analysis of oil and grease in synthetic produced water. Results from the UV-Vis spectrophotometric and FTIR spectrometric analytical methods were found to be comparable; it confirmed that UV-Vis spectrometry could potentially serve as an alternative method for measuring oil and grease in oil field produced water. However, while the UV-Vis method may have limitations in measuring oil and grease concentrations below 30 mg/L, the FT-IR method was found to be equally efficient at measuring both high and low oil and grease concentrations. Dissolved air flotation (DAF) was the primary treatment technology investigated in this study for removing oil and grease from synthetic produced water. By itself, DAF achieved less than 70% oil and grease (OG) removal, and was not able to achieve a clarified effluent OG concentration of 30 mg/L required for regulatory discharge limits. At an optimum condition of 20 mg/L ferric chloride (FeCl3) at pH 8 (70.6% OG removal), coagulation was found to significantly improve the performance of the DAF unit (p < 0.05). At the optimum conditions of 100 mg/L PAC dose, pH 8 and a mixing time of 10 minutes (77.5% OG removal) and 300 mg/L OC dose, pH 8 and a mixing time of 10 minutes (78.1% OG removal), adsorption was also found to significantly improve the performance of the DAF unit (p < 0.05 in both cases). Adsorption with organoclay was recommended as the best pre-treatment for optimizing the performance of DAF in removing oil and grease from offshore oil field produced water. The bench-scale experiments showed that turbidity removal results were consistent with the OG removal results. Without pre-treatment, DAF achieved significant removal of benzene from produced water due to the volatile nature of benzene. Therefore comparable levels of benzene removal was observed by the DAF, FeCl3/DAF, PAC/DAF and OC/DAF treatment schemes; 79.3 %, 86.6 %, 86.5 %, 83.5% respectively. Finally, as benzene is known to be carcinogenic to humans, this study recommends the incorporation auxiliary equipment in its design, for the treatment of the off-gas (VOCs, particularly BTEX) released during the removal of dissolved oil from the oil field produced water.

Le développement de nanomédicaments capables de contrecarrer les propriétés biopharmaceutiques défavorables de l'amphotéricine B (AmB) représente un enjeu important. L'AmB est en effet une molécule très efficace pour le traitement des infections fongiques systémiques et aussi pour la leishmaniose, mais difficile à formuler efficacement, quelle que soit la voie d'administration. Cette molécule particulièrement hydrophobe souffre de limitations importantes en raison de sa tendance prononcée à l'agrégation dans les conditions physiologiques. La première partie de cette thèse a consisté à vérifier l'hypothèse selon laquelle le degré d'agrégation de l'AmB pourrait avoir un fort impact sur certaines de ses propriétés biopharmaceutiques et pharmacocinétiques. Dans cet objectif, l'albumine a été utilisée pour produire avec l'AmB des complexes de taille contrôlée. Les caractéristiques morphologiques des objets colloïdaux formés ont été déterminées par spectroscopie UV-Vis et par dichroïsme circulaire. Ainsi, l'impact de l'état de l'agrégation sur la perméabilité intestinale d'une part et la reconnaissance éventuellement des agrégats par le système immunitaire d'autre part a été étudié. La deuxième partie de ce travail a été axée sur le développement des micro et nanotransporteurs destinés à surmonter la barrière d'absorption élevée contre AmB après son administration orale. À cet effet, des micro- et nano-émulsions chargées en AmB ont été préparée afin d'estimer leur capacité à améliorer la perméabilité de l'AmB au travers de l'épithélium digestif de rat. Le modèle de la Chambre d’Ussing a été utilisé à cet effet. Aucun passage de l’AmB n'a pu être détecté dans chacune des conditions expérimentales testées. Toutefois, les données électrophysiologiques ont montré une diminution de la viabilité des tissus, attribuable à la grande toxicité de l'AmB, et dépendante de l'état d'agrégation de l'AmB lorsque ces objets sont au contact avec le tissu. Ces essais de perméation menés sur des tissus sains au niveau jéjunal suggèrent que le transport de l'AmB par les voies paracellulaire et/ou transcellulaire est sans doute marginal. Cependant, la littérature rapporte que qu'une absorption par voie orale de l'AmB, bien que peu importante, peut être observée in vivo. Ceci suggère donc que d'autres voies d'absorption pourraient être mises en oeuvre, parmi lesquelles la capture d'agrégats d'AmB au niveau des plaques de Peyer et l'accès à la voie lymphatique pourraient représenter des voies d'absorption alternatives. Enfin, l'emploi d'un autre système de transporteur conçu pour atteindre le colon et assurer la délivrance colonique grâce à l'action enzymatique bactérienne locale a été envisagé. Dans cet objectif, un biopolymère naturel et dégradable par des enzymes, le xylane, a été sélectionné. Le xylane est un polysaccharide présent dans les grains, de céréales et de plantes angiospermes qui est spécifiquement dégradé dans la région du côlon, grâce à l'action enzymatique du microbiote. Pour cela, un procédé original de préparation de particules a été mis en oeuvre consistant tout d'abord à produire une émulsion eau-dans-eau de xylane en présence de PEG, suivie d'une phase de réticulation du xylane au moyen du trimétaphosphate de trisodium. La méthode a permis la production de nano et de microparticules allant de 380 nm à 4,5 μm et les paramètres contrôlant le processus ont été identifiés. Ce processus, respectueux de l'environnement et ne nécessitant pas l'emploi de solvants organiques, pourrait être appliqué à la délivrance colonique de AmB. / This thesis is part of the development and evaluation of nanomedicines potentially able to overcome unfavorable biopharmaceutical properties of amphotericin B (AmB), a highly effective molecule used for the treatment of systemic fungal infections and leishmaniasis, but difficult to formulate efficiently, whatever the route of delivery. It is believed that this hydrophobic molecule suffers from severe limitations due to its prounounced tendency to aggregate under physiological conditions. The first part of the thesis was driven on the hypothesis that the degree of aggregation of AmB could have a strong impact on some of its pharmacokinetics properties. For this purpose albumin has been used to produce controlled complexes between albumin and AmB in order to control AmB aggregation states. The morphological characteristics of the resulting colloidal objects have been carefully characterized by UV-Vis spectroscopy and circular dichroism. Furthermore, the impact of aggregation state on both the intestinal permeability and a possibly expected recognition of the aggregates by the immunological system were investigated. The second part of this work was focused on the development of micro- and nanocarriers intended to overcome the absorption barrier raised against AmB after oral delivery. For this purpose, AmB was loaded into micro- and nanoemulsions to evaluate a possible permeability enhancement effect through the intestinal membrane, which was evaluated in ratas using the Ussing chamber model. No detectable permeation was seen in any of the experimental conditions. However, the electrophysiological data showed tissue viability losses due to the strong toxicity of AmB, that were dependent on the agregation state of AmB when in contact with the tissue. It was also concluded from detailed permeation experiments in healthy tissues that paracellular and transcellular routes were likely to be only marginal pathways when oral absorption are observed in vivo, as reported in the literature. The likeness of other possible absorption pathways, including Peyer's patches capture and lymphatic pathway implication for agregated particles has been discussed. Finally, another particulate system intended for colonic delivery and based on xylan, a natural and enzymatically degradable biopolymer, has been investigated. Xylan is a polysaccharide present in grains, cereals and angiosperm plants that is specifically degraded on colon region, by the microbiota. An original process consisting in a water-in-water emulsion of xylan in presence of PEG followed by a crosslinking phase using trisodium trimetaphosphate has been developed, making possible the production of xylan-based biocompatible micro- and nanospheres ranging from 380 nm to 4.5 μm, depending on the parameters in the process. This eco-friendly process is free of harmful solvents and has potential application for the delivery of AmB at the colonic level.