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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Étude du rôle d’adsorbants alumino-silicatés dans un procédé d’ozonation d’eaux usées pétrochimiques / Study of the alumino-silicate adsorbents role in a petrochemical wastewater ozonation process

Aboussaoud, Wael 17 July 2014 (has links)
Les eaux usées issues de l’industrie pétrochimique contiennent des composés organiques peu ou pas biodégradables dont le traitement nécessite de faire appel à des nouvelles techniques de traitement sophistiquées. L’objectif de ce travail est d’étudier le rôle d’adsorbants alumino-silicatés dans un procédé d’oxydation avancée associant, dans un même réacteur, adsorption et oxydation à l’ozone pour le traitement de ce type d’effluents. Dans un premier temps, l’étude s’est centrée sur l’évaluation des performances du procédé pour l’élimination d’une molécule modèle, le 2,4-diméthylphénol, dans un réacteur agité semi-batch. Avant de coupler l’ozonation et l’adsorption, chacun des phénomènes mis en jeu a été étudié indépendamment, ce qui a permis la compréhension des mécanismes qui régissent le couplage. Deux modes de couplage ont été testés, un traitement simultané ozonation/adsorption et un traitement séquentiel ozonation puis adsorption. Dans les deux configurations, l’ajout des matériaux alumino-silicatés a eu un effet très limité sur la cinétique globale de dégradation de la molécule modèle. Par contre, l’ajout des matériaux a un effet très marqué sur la cinétique d’élimination du COT, principalement dû à un effet d’adsorption de sous-produits d’oxydation spécifiques. Il a aussi été démontré que la restauration des propriétés du solide est possible, permettant ainsi sa réutilisation. Dans un second temps, le procédé a été appliqué au traitement d’un effluent réel rejeté par une usine pétrochimique chinoise, en suivant la même démarche que celle adoptée lors de l’étude réalisée sur la molécule modèle et en utilisant un réacteur à lit fluidisé semi-batch. Les mêmes phénomènes ont été observés, confirmant l’efficacité de ce procédé pour le traitement des eaux usées pétrochimiques. / Petrochemical wastewaters often contain hardly biodegradable organic compounds requiring the use of sophisticated treatment techniques to be eliminated. The aim of this work is to study the role of alumino-silica adsorbents in an advanced oxidation process combining, in the same reactor, adsorption and ozonation for the treatment of such effluents. Initially, the study focused on the evaluation of process performance for the removal of a target molecule, 2,4-dimethylphenol, in a stirred semi-batch reactor. Before coupling adsorption and ozonation, each of these techniques has been studied independently, which allowed the well understanding of the mechanisms taking place during the combined process. Two process configurations were tested; a simultaneous ozonation/adsorption process and a sequential process including a first ozonation step followed by an adsorption step. In both cases, the addition of alumino-silica materials had a very limited effect on the overall kinetics of degradation of the target molecule. However, the use of the materials had a beneficial effect on TOC removal, mainly due to an adsorption effect of specific oxidation by-products. It was also shown that the restoration of the material properties is possible, allowing its reuse. In a second time, the process has been applied to the treatment of a real effluent discharged by a Chinese petrochemical plant, following the same approach adopted in the study of the target molecule and using a semi-batch fluidized bed reactor. Similar phenomena were observed, thus confirming the efficiency of the process on petrochemical wastewater treatment.
42

Výskyt a interakce jodu v přírodním prostředí se zaměřením na hydrosféru. / The occurrence and interactions of iodine in a natural environment, focused on the hydrosphere.

ŠEDA, Martin January 2013 (has links)
Iodine is an important element essential for higher animals. A large part of the global human population suffers from a lack of iodine; elucidation of transfer and mobility of this element in the environment, water, soil, air and in organisms is thus very important. The aim of this work was the elaboration and optimisation of the method for determination of very low concentrations of iodine in the waters. The mass spectrometry with inductively coupled plasma (ICP-MS) technique was used. It has been shown that using of different filter types during sample preparation had no significant effect on the content of impurities in the filtered sample. Antimony was recommended as an internal standard, despite commonly used elements (indium or tellurium). Samples were not preserved because nitric acid caused volatilization of iodine from the sample and the addition of aqueous ammonia had no significant effect. The optimised method was tested on several groups of water samples, including precipitation, surface water and lysimetric waters. From autumn 2009 to summer 2010, a part of the Blanice River (Šumava Mountains, South Bohemia) was sampled. The average content of iodine in samples ranged from 1.48 ? 0.30 ?g?dm-3 (April 2010) to 3.05 ? 0.38 ?g?dm-3 (July 2010). The average content of iodine in samples from all tributaries of the Blanice River ranged between 2.52 ? 1.63 ?g?dm-3 (March 2010) and 3.67 ? 1.37 ?g?dm-3 (July 2010). The concentration of iodine in the monitored surface waters did not change significantly along the flow of the river. The other two streams were sampled near Rapotín village (Jeseníky Mountains, north Moravia). The average contents of iodine were as follow: Annov (upper stream) 1.60 ? 0.65 ?g?dm-3, Annov (lower stream) 1.88 ? 1.18 ?g?dm-3, Salaš (upper stream) 1.77 ? 0.92 ?g?dm-3, Salaš (lower stream) 1.42 ? 0.58 ?g?dm-3. Generally, the data showed that considering iodine, the area of Šumava had slightly higher levels than those observed in the Jeseníky Mountains. Precipitation collected in the South Bohemia (Arnoštov village and city of České Budějovice) and in Jeseníky (Rapotín) contained less iodine compared to surface waters, and rarely exceeded 3 micrograms per liter of water. The situation has changed in the spring of 2010, because of the occurrence of volcanic dust and ash over the Czech Republic. This volcanic cloud came from the sudden activity of the Eyjafjallajökull Volcano (Iceland). In the mentioned period, the contents of iodine in precipitation were increased several times at all sample collection sites. This is an indirect evidence that iodine could be released during volcanic eruptions and transferred over long distances through the atmosphere. It turned out that the wastewater treatment plant can eliminate iodine in wastewater only partially. However, the wastewater treatment plants in the monitored region were too small to evaluate the overall impact on the environment. The maximum iodine content at the outlet of the wastewater treatment plant Prachatice town (South Bohemia) was 28.5 ?g?dm-3, which is several times higher than natural levels in the Živný stream, to which the treated water flows. Lysimetric water samples were collected from lysimeters installed in three nearby plots in Arnoštov village (Šumava, South Bohemia). The highest concentrations of iodine were found on plot where cattle were grazed. These values were significantly higher (average 4.38 ? 1.74 ?g?dm-3) than those obtained from a site used as hay meadow (average 2.69 ? 1.19 ?g?dm-3) or an untreated meadow (average 2.25 ? 1.39 ?g?dm-3). Iodine therefore probably originated from the urine and feces of grazed cattle. This thesis contributes to the total knowledge of iodine, particularly to the part concerning determination of iodine in the hydrosphere.
43

Tratamento de esgoto sanitário em reator anaeróbio horizontal de leito fixo (RAHLF): escala piloto / Treatment of domestic sewage in a horizontal-flow anaerobic immobilized biomass (HAIB) reactor: pilot scale

Cláudio Antônio de Andrade Lima 24 August 2001 (has links)
Este trabalho apresenta as avaliações de desempenho, das demandas operacionais e dos fatores intervenientes no aumento da escala da unidade piloto do Reator anaeróbio Horizontal de Leito Fixo (RAHLF) no tratamento de esgoto sanitário após passagem por peneira com malha de 1 mm, durante dois anos de operação. O reator dispunha de volume total de 237,5 1, construídos com tubos comerciais de PVC de 14,5 cm de diâmetro (D), dispostos em cinco módulos horizontais em série de 2,88 m, perfazendo um comprimento total de (L) de 14,4 m e relação de total de L/D de 100. O suporte de imobilização de biomassa, espuma de poliuretano em matrizes cúbicas de 1 cm de aresta, mostrou-se adequado ao desenvolvimento do biofilme. Em partida, sem inoculação prévia, ocorreu a sua consolidação a partir de 70 dias, com predominância de morfologia semelhante a Methanosaeta sp. em relação a da Methanosarcina. Em torno de 90 dias com afluente de 350 mg/l de DQO, observe-se a melhor qualidade do efluente, com valor de 100 mg/l de DQO. Em longa operação ocorreu queda de rendimento e menor reprodutibilidade das previsões do projeto, atribuída aos constantes entupimentos e ineficácia das operações de limpeza, com o comprometimento de volume reacional verificados por estudos de hidrodinâmica. Da investigação das origens dos equipamentos observou-se tratar mais de um efeito local e qualitativamente relacionado à biomassa retida que propriamente quantitativo e extensivo ao longo de todo reator, com produção continuada de polímeros extracelulares, promovendo um efeito sinérgico com os predominantes organismos filamentosos e com os sólidos particulados retidos no leito. Diante das potencialidades desta configuração de reator apontam-se alternativas de mitigação dos entupimentos e o direcionamento dos estudos necessários para novo aumento de escala para o tratamento de esgoto sanitário. / This work evaluated the performance, the operational demands and the intervenient factors in the scale-up of the horizontal flow anaerobic immobilized biomass (HAIB) reactor pilot unit, treating domestic sewage previously screened. The operation was monitored for two years. The five- module (2.88 m length each) reactor volume was 237.5 liters and it was built with commercial PVC pipes of 14.5 cm of diameter (D), resulting in a total length (L) of 14.4 m and in a total ratio L/D of approximately 100. The immobilization support, cubic matrices of polyurethane foam (1 cm edge), showed to be suitable for the anaerobic biofilm development. During the start-up, without previous inoculation, the biofilm seemed to be consolidated after 70 days, and Methanosaeta sp. morphology predominated, in detriment of Methanosarcina. With an affluent of 350 mg COD/L, the best reactor performance was observed in about 90 days of operation (100 mg COD/L in the effluent). However, with the continuous operation, its performance decreased and the project predictions did not seem to fit anymore. These facts were probably due to the frequent cloggings ant the inefficiency of the backwashing procedures, leading to a decreasing of the operational volume. The origin of the clogging seemed to be related to the extracellular polymer production, linked to a synergic effect with the filamentous organisms and the particulate solids in the bed. Despite these operational problems, there were found alternatives to mitigate the clogging, and studies about a new scale-up methodology, in order to treat domestic sewage, were strongly recommended.
44

Reclamation of VOCs, n-butanol and dichloromethane, from sodium chloride containing mixtures by pervaporation:towards efficient use of resources in the chemical industry

García, V. (Verónica) 13 October 2009 (has links)
Abstract Volatile Organic Compounds (VOCs) in wastewaters from the chemical industry are of major concern because of their environmental and health impacts. The reclamation of VOCs from wastewaters would not only reduce the hazard to the environment but also contribute to an efficient use of resources. The thesis explores the reclamation of n-butanol and dichloromethane from sodium chloride containing mixtures by pervaporation. Another aim was to gain understanding of mass transport phenomena during the pervaporation of multicomponent systems, and the effect of sodium chloride on the pervaporation performance. In this work, the reclamation of n-butanol and dichloromethane was conducted as a sequence of pervaporation stages which utilised first hydrophobic and then hydrophilic membranes. The objective was to segregate the mixture of n-butanol/dichloromethane/sodium chloride/water into three different streams: a re-use quality concentrate of VOCs, brine, and discharge quality purified water. The effect of the experimental variables, VOCs feed concentration, feed temperature and sodium chloride content on the performance of the pervaporation stages was studied. A statistical design, response surface methodology, was used to further resource efficiency. The results indicate the potential of pervaporation for the reclamation of n-butanol and dichloromethane from aqueous mixtures. A single step of pervaporation of n-butanol/dichloromethane/sodium chloride/water systems using the CMX-GF-010-D (Celfa) and PERTHESE® 500-1 (P 500-1) membranes does not sufficiently concentrate the VOCs for direct re-use. It is also demonstrated that the electrolyte does not permeate through the membranes and does not affect their separation effectiveness significantly. The pervaporation of the water/dichloromethane/n-butanol system using the hydrophilic poly(vinyl alcohol)-titanium dioxide/polyacrylonitrile/polyphenylene sulfide (PVA-TiO2/PAN/PPS) membrane is effective for dewatering purposes. The membrane shows impermeable features towards dichloromethane in the studied conditions. The analysis of the mass transport phenomena demonstrates that, under the experimental conditions studied, the resistance towards the mass transport of the compounds through the membrane is mainly exhibited by the membrane itself. This study also shows the advantage of analysing the effect of temperature on membrane permeation by the permeation activation energy instead of by the apparent activation energy.
45

Présence, devenir et traitement des biocides dans les rejets d'un établissement hospitalier / Occurence, fate and treatment of biocides from a University Hospital wastewater network

Lasek, Florence 11 December 2018 (has links)
L’objectif de ce travail a été d’étudier la présence, le devenir et le traitement de biocides dans les rejets d’un établissement hospitalier. Pour cela, 3 substances biocides, représentatives d’une activité de soins (i.e. didécylmethylammonium (DDAC), digluconate de chlorhexidine (CHD) et bis(aminopropryl)laurylamine (BAPLA)) ont été ciblées et 5 campagnes de prélèvements réalisées sur l’ensemble du réseau de collecte des eaux usées du CHU de Poitiers ont été menées. Dans ces conditions, une émission continue de biocides sur 24 h, avec des quantités rejetées en journée plus importantes du fait de la plus forte activité de soins et de nettoyage durant cette période a été montrée. Des concentrations de l’ordre de quelques mg/L pour le DDAC et de quelques dizaines de µg/L pour le CHD et le BAPLA ont été observées. En termes de flux massiques, la comparaison des quantités retrouvées dans les rejets aux quantités utilisées par le CHU a permis de préciser la nature des sources d’émission ainsi que les usages et/ou les pratiques les plus propices à ces rejets.Parallèlement, une étude laboratoire de la stabilité et du devenir des biocides dans les eaux résiduaires a été menée. Une première estimation des quantités adsorbées sur les matières en suspension a été obtenue. De même, les produits de dégradation susceptibles d’être générés lors du rejet de biocides en présence d’un résiduel de chlore ont été identifiés et l’évolution de l’écotoxicité vis-à-vis de Vibrio fisheri a été évaluée.Enfin, la possibilité d’un traitement à la source utilisant l’ozone pour limiter les rejets de biocides a été envisagée et une étude pilote sur le terrain a été menée. / The objectives of this study was to study the presence, the fate and the treatment of some biocides in the wastewaters from a hospital. 3 biocidal substances specific to healthcare activities (i.e. didecylmethylammonium chloride (DDAC), chlorhexidine digluconate (CHD) and bis(aminopropryl)laurylamine (BAPLA)) were selected and 5 sampling campaigns were conducted throughout the entire Poitiers University Hospital sewage system. Under these conditions, a continuous biocide discharges over 24 h was shown, with higher quantities discharged during the day. This was pointing out the greater healthcare and facility cleaning activities taking place during this period. Concentrations of a few mg/L for DDAC and a few dozens of µg/L for CHD and BAPLA were detected. In terms of mass flows, the comparison of the quantities found in the discharges with the quantities used by the university hospital made it possible to specify the nature of the sources of emission as well as the uses and / or the practices most favorable to these discharges.In parallel, a laboratory study of the stability and fate of biocides in wastewater was conducted. A first estimate of the amounts adsorbed on suspended solids was obtained. Similarly, the degradation products likely to be generated during the release of biocides in the presence of a chlorine residual have been identified and the evolution of the ecotoxicity towards Vibrio fisheri has been evaluated.Finally, the proposal of an ozone based treatment at source was carried out to limit biocide discharges and a pilot study was conducted on the hospital wastewaters.
46

Organic acid coated magnetic nanparticles as adsorbent for organic pollutants in aqueous solution.

Masuku, Makhosazana Nancy 03 1900 (has links)
M. Tech. (Chemistry Department, Faculty of Applied and Computer Sciences) Vaal University of Technology. / Benzene, toluene and xylene (BTX) are water pollutants that appear very often in chemical and petrochemical wastewaters due to gasoline leakage from storage tanks and pipelines. These BTX compounds can cause adverse health effects on humans even at very low concentrations. Amongst the available pollutant removal methods from wastewater, adsorption has been used due to its ease of operation, simplicity and cost-effectiveness. Different adsorbents have been used for BTX removal, however the use of Magnetite-organic acid composites as an adsorbent seems to offer a much cheaper alternative. This work seeks to develop a one-step microwave synthesis and optimization of magnetite-oleic (MNP-OA) and magnetite-palmitic (MNP-PA) acid) composites. Response surface methodology was used to optimize the magnetite-organic acid composites. The optimum conditions estimated for MNP-OA acid composite were 78.3 % Fe content, 1561.9 S/cm conductivity, 82.2, 84.1, 85.3 mg/g for BTX adsorption capacity. The MNP-PA composite were 75.6 % Fe content, 1325.66 S/cm conductivity, 60.55, 64.47, 63.06 mg/g for BTX adsorption capacity. The materials were characterized, and the adsorption process was optimized for BTX removal from aqueous solution. X-ray analysis confirmed the formation of magnetite by the presence of both ferric and ferrous ion states on the surface. It was noted that after modification, the magnetite-organic acids characteristics peaks became broad and the height of the peaks decreased indicating that surface modification with organic acid controls the crystallinity of the material. The average cystalline size of MNP, MNP-OA, and MNP-PA composites were 19.7, 17.1 and 17.9 nm. FTIR analysis confirmed the target materials were produced and also to determine if the organic acids were imobilised on the surface of the magnetite. TEM images presented that the MNP, MNP-OA, and MNP-PA composites were spherical in shape with particle average sizes of 18.4 ± 0.5, 15.6 ± 0.5 and 16.5 ± 0.5 nm. The magnetite-organic acids show the particles with better isolated as compared to that of the MNP. The BET isotherms of the materials were described by a type IV characteristic related to uniform mesoporous materials. The magnetic saturation value for MNP, MNP-OA, and MNP-PA composites were 62.9, 59.0 and 51.0 emu/g. The decrease in magnetization was explained by the presence of the non-magnetic layer on magnetite surface. The pHpzc of MNP, MNP-OA, and MNP-PA composites were 6.9, 6.4 and 6.1. The decrease in pHpzc aftern modification was due to the charging acid-base interaction mechanism of metal oxide nanoparticles. The optimum pH for the adsorption of BTX onto MNP, MNP-OA, and MNP-PA composites was determined to be pH 7 for benzene, pH 8 for toluene and xylene. Among the three pollutants, xylene had the highest adsorption capacity followed by toluene and benzene. The optimum adsorbent dose for the adsorbents for the adsorption process was 0.1 g/dm3. The effect of time on the uptake of BTX onto MNP, MNP-OA, and MNP-PA composites show that initial adsorption of BTX occured between 0 and 3 min of contact time. The effect of initial concentration results shows the initial concentration of BTX increases from 100 to 350 mg/dm3 with an increase in adsorption capacity. The results suggest that the adsorption process is controlled by concentration driving force. The experimental data was fitted to the pseudo-first and pseudo-second-order kinetic models for all adsorbents and all pollutants. The pseudo-second-order models showed good correlation as compared to the first-pseudo model. Desorption studies for benzene, toluene and xylene using the pure magnetite, magnetite-palmitic and magnetite oleic acid composites indicate adsorption mrchanism can be explained in relation to acid–base chemistry. Electron donation from the phenyl ring of each benzene, toluene and xylene compound to surface iron atoms of magnetite has been suggested. The CH3OH and H2O desorbing agents were used and regeneration using five cycles show that the percentage desorption decreses from Benzene < Toluene < Xylene. The reduction in adsorption capacity after the cycles are attributed to decomposition of the adsorbents active sites and mass loss of the sample.
47

Séparation, détection et caractérisation de nanoparticules manufacturées dans des eaux naturelles et usées avec la chromatographie hydrodynamique et de multiples détecteurs

Proulx, Kim 10 1900 (has links)
L’utilisation accrue des nanomatériaux manufacturés (NM) fait en sorte que les différents acteurs de réglementation se questionnent de plus en plus par rapport à leur destin et leurs impacts sur les écosystèmes et la santé humaine suite à leur rejet dans l’environnement. Le développement de techniques analytiques permettant de détecter et de caractériser les NM en matrice environnementale est impératif étant donné la nécessité d’évaluer le risque relié à ces polluants émergents. Une des approches de plus en plus favorisée est d’utiliser une technique chromatographique et un ou plusieurs détecteurs sensibles dans les buts de réduire les effets de matrice, d’identifier des nanoparticules (NP) selon leurs temps de rétention et de les quantifier à des concentrations représentatives de la réalité environnementale. Une technique analytique utilisant la chromatographie hydrodynamique (HDC) et des détecteurs en ligne ou hors ligne (détecteurs de diffusion statique ou dynamique de la lumière, spectromètre de masse par torche à plasma en mode particule unique (SP-ICPMS), l’ultracentrifugation analytique) a donc été développée. Le couplage de la colonne HDC avec ces détecteurs a permis de caractériser des NP standards et l’optimisation des conditions de séparation de ces nanoparticules de polystyrène, d’or et d’argent a permis de confirmer que les NP y sont bel et bien séparées seulement selon leur taille, tel que la théorie le prédit. De plus, l’utilisation de la colonne HDC couplée au SP-ICPMS a permis de séparer un mélange de nanoparticules d’argent (nAg) et de les détecter à des concentrations représentatives de celles rencontrées dans l’environnement, soit de l’ordre du μg L-1 au ng L-1. Par exemple, dans un échantillon d’eau usée (effluent), un mélange de nAg de 80 et de 40 nm a été séparé et les nAg ont été détectées à l’aide du SP-ICPMS connecté à la colonne HDC (temps de rétention de 25.2 et 25.6 minutes et diamètres déterminés de 71.4 nm et 52.0 nm). Finalement, pour plusieurs échantillons environnementaux auxquels aucun ajout de nanoparticules n’a été fait, les analyses HDC-SP-ICPMS effectuées ont permis de déterminer qu’ils ne contenaient initialement pas de nAg. / Due to the widespread use of engineered nanoparticles (ENP), regulatory agencies are very concerned about their fate and their impacts on the environment and on human health. The development of analytical techniques, which will allow the detection, characterization and quantification of ENP in environmental matrices, is therefore critical in order to properly evaluate the exposure associated with these emerging pollutants. One promising approach to detect and quantify the nanoparticles is to couple a chromatographic technique to a sensitive detector in order to: (i) reduce matrix effects; (ii) identify nanoparticles from their retention times and (iii) quantify the ENP at environmentally relevant concentrations. Consequently, the coupling of hydrodynamic chromatography (HDC) was performed with both on-line and off-line detectors (light scattering detectors, inductively coupled plasma mass spectrometer in its single particle mode (SP-ICPMS) and an analytical ultracentrifuge). HDC was first used for the characterization of ENP standards. Separation conditions were optimized for standard nanoparticle suspensions of polystyrene, gold and silver, which allowed us to confirm that the separation was occurring, based on hydrodynamic size, as predicted by theory. By coupling the HDC column to the ICPMS detector in its ‘‘single particle’’ mode, it was possible to separate an ENP mixture and to detect the nanoparticles at environmental concentrations, i.e., in the μg L-1 to ng L-1 range. For example, in a wastewater sample (effluent wastewater), a mixture of two silver nanoparticles (nAg) of 40 and 80 nm were separated and the nAg were detected by SP-ICPMS at retention times of 25.2 and 25.6 minutes. Diameters of 71.4 nm and 52.0 nm were found. HDC-SP-ICPMS analysis carried out on different non-spiked wastewater samples allowed us to conclude that nAg was below the detection limit of 0.1 µg L-1.
48

Etude d'un procédé d'ozonation catalytique pour l'élimination des micropolluants dans les effluents urbains / Etude d’un procédé d’ozonation catalytique pour l’élimination des micropolluants dans les effluents urbains

Crousier, Claire 10 December 2015 (has links)
Les travaux menés au cours de cette thèse ont pour objectif d’étudier l’applicabilité du procédé d’ozonation catalytique TOCCATA® au traitement avancé d’eaux résiduaires urbaines pour le contrôle des émissions en micropolluants. Ce travail couvre la détermination des propriétés physico-chimiques, structurelles et de réactivité de deux catalyseurs et l’optimisation de leur conditionnement pour le procédé d’ozonation catalytique. La caractérisation hydrodynamique du réacteur à co-courant ascendant triphasique en lit fixe utilisé pour la mise en œuvre du procédé a été également réalisée. Les processus élémentaires impliqués dans le procédé ont ensuite été étudiés séparément : transfert gaz-liquide, adsorption, ozonation simple et interaction ozone/matériau. Enfin l’ozonation catalytique a été étudiée vis-à-vis de l’élimination de la matière organique des eaux usées réelles. L’ozonation catalytique se montre moins sélective que l’ozonation simple et améliore le procédé en termes de transfert d’ozone et d’élimination du carbone organique. Des mécanismes et des lois cinétiques pour chacun des processus élémentaires ont été déterminés et une loi de vitesse globale de premier ordre pour le procédé d’ozonation catalytique est proposée. L’étude de l’influence de différentes variables opératoires a été effectuée en vue de l’optimisation du procédé. L’investigation a ensuite été élargie à l’élimination de micropolluants spécifiques (carbamazépine, diuron, kétoprofène, diclofénac, naphtalène) appliquée à des eaux synthétiques, ainsi qu’à des eaux résiduaires urbaines réelles. La plupart des composés sont dégradés après application d’une faible dose d’ozone par le procédé. L’étude de leurs propriétés et de leur affinité avec le système d’ozonation catalytique a permis d’expliquer leurs comportements. / This thesis aimed to study the application of the TOCCATA® catalytic process to urban wastewaters treatment in order to control micropolluant emissions. This work first focused on physico-chemical, structural and reactional properties of two catalysts and on the optimization of their conditioning for the use in the catalytic process. The hydrodynamic characterisation of the fixed bed triphasic co-current upflow reactor used for this study was realized. Elementary processes involved in the process were studied separately: gas-liquid transfer, adsorption, single ozonation, ozone/catalyst interactions. Catalytic ozonation was then investigated for the elimination of organic matter contained in real urban wastewaters. Catalytic ozonation appeared to be less selective than single ozonation and to improve the process in terms of ozone transfer and organic carbon removal efficiency. Mechanisms and kinetic laws were determined for each elementary process and a global first order kinetic law was proposed for catalytic ozonation. The study of various operating conditions (liquid and gas flows, ozone dose …) was conducted in order to optimize the process efficiency.Investigations were then extended towards specific micropollutants elimination (carbamazepine, diuron, ketoprofen, diclofenac, naphtalene) onto synthetic waters as well as real urban wastewaters. Most of the compounds were eliminated with low dose ozonation by the TOCCATA® catalytic ozonation process. The properties of the micropollutants and their affinities with the catalytic ozonation system were studied in order to explain their behaviours.
49

Compara??o entre planejamento estat?stico experimental e an?lise dimensional em opera??es de mistura e separa??o para sistema ?leo-?gua

Moraes, Norberto Araujo de 30 September 2011 (has links)
Made available in DSpace on 2014-12-17T15:01:52Z (GMT). No. of bitstreams: 1 NorbertoAM_TESE.pdf: 2336588 bytes, checksum: 940ad1b0befe8c431d2e9fb731a885b6 (MD5) Previous issue date: 2011-09-30 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / This work aims to determine a better methodology to help predicting some operational parameters to a new design of mixer-settler on treating wastewater produced by petroleum industry, called MDIF (Misturador-Decantador ? Invers?o de Fases/ Mixer-Settler based on Phase Inversion MSPI). The data from this research were obtained from the wastewater treatment unit, called MSPI-TU, installed on a wastewater treatment plant (WTP) of PETROBRAS/UO-RNCE. The importance in determining the better methodology to predict the results of separation and extraction efficiency of the equipment, contributes significantly to determine the optimum operating variables for the control of the unit. The study was based on a comparison among the experimental efficiency (E) obtained by operating MSPI-TU, the efficiency obtained by experimental design equation (Eplan) from the software Statistica Experimental Design? (version 7.0), and the other obtained from a modeling equation based on a dimensional analysis (Ecalc). The results shows that the experimental design equation gives a good prediction of the unit efficiencies with better data reliability, regarding to the condition before a run operation. The average deviation between the proposed by statistic planning model equation and experimental data was 0.13%. On the other hand, the efficiency calculated by the equation which represents the dimensional analysis, may result on important relative deviations (up 70%). Thus, the experimental design is confirmed as a reliable tool, with regard the experimental data processing of the MSPI-TU / Este trabalho objetiva determinar a melhor metodologia para auxiliar na predi??o de vari?veis operacionais de um novo design de misturador-decantador aplicado ao tratamento de ?guas produzidas da ind?stria do petr?leo, que vem sendo denominado de MDIF (Misturador-Decantador ? Invers?o de Fases). Os dados utilizados neste estudo foram obtidos da Unidade de Tratamento de ?guas produzidas, denominada de UT-MDIF, que se encontra instalada em uma das esta??es de tratamento de efluentes (ETE) da PETROBRAS/UORNCE. A import?ncia em determinar a melhor metodologia que permita a predi??o dos resultados das efici?ncias de separa??o e extra??o do equipamento, contribui de forma significativa para otimiza??o das vari?veis operacionais para o controle da unidade. O estudo se baseou na compara??o dos resultados das efici?ncias experimentais (E) obtidas pela UTMDIF, com os resultados das efici?ncias obtidas pela equa??o do modelo do planejamento estat?stico (Eplan), gerado pelo programa Statistica Experimental Design? (vers?o 7.0), e com a utiliza??o de uma equa??o utilizando modelagem com base em an?lise dimensional (Ecalc). Os resultados mostram que a equa??o decorrente do planejamento estat?stico ? capaz de predizer, com boa aproxima??o, os resultados de efici?ncia a serem obtidos com a unidade, possibilitando uma melhor confiabilidade dos dados, no que se refere ? condi??o que antecede uma corrida operacional. O desvio m?dio entre a equa??o proposta e os dados experimentais ? de 0,13%. Por outro lado, a efici?ncia calculada pela equa??o da an?lise dimensional pode apresentar desvios relativos importantes (at? 70%). Desta forma, o planejamento estat?stico experimental se confirma como sendo uma ferramenta confi?vel, no que se refere ao tratamento dos dados experimentais da UT-MDIF
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Écologie et dangerosité des Pseudomonas aeruginosa des milieux aquatiques anthropisés / Ecology and health hazard of Pseudomonas aeruginosa from human impacted water

Petit, Stéphanie 21 September 2012 (has links)
En santé publique, de nouveaux programmes de surveillance et de gestion sont à proposer notamment pour les masses d'eaux fortement affectées par l'urbanisation et les rejets urbains par temps de pluie. Les niveaux, les réservoirs et les sources de contamination microbiologique des milieux aquatiques doivent être évalués et identifiés, et leur incidence sur la dissémination des bactéries pathogènes et les risques d'exposition des populations humaines comprises. Parmi les agents pathogènes retrouvés dans les milieux hydriques, Pseudomonas aeruginosa représentent une préoccupation sanitaire majeure. A partir de deux sites expérimentaux, les objectifs de ce travail de thèse furent de définir la contribution des rejets d'eaux usées sur la prévalence de P. aeruginosa dans les cours d'eau récepteurs et d'étudier l'écologie des formes introduites dont ces habitats incluant leur dynamique spatiotemporelle. Les sédiments, les biofilms de surface (périphyton) et les végétaux aquatiques submergés, permettraient leur survie voire la multiplication de certains génotypes de Pseudomonas aeruginosa. La répartition des indicateurs de contaminations fécales et de la bactérie pathogène Aeromonas caviae ont également été étudiée. Il a été mis en évidence que les forces hydrauliques, le morpho-dynamisme de la rivière et les variations saisonnières étaient des facteurs structurants de la répartition des contaminants microbiens analysés. La dangerosité des souches isolées a été évaluée et montré que toutes les souches avaient un potentiel de virulence élevée. Ceci s'est confirmé par la détection de clones épidémiques majeurs au sein de la collection dont des souches apparentées aux clones PA14 ou C. Les capacités métaboliques de ces souches ont été étudiées dont leur antibio-résistance / In Public Health, new monitoring and management programs are needed, especially for the aquatic environments strongly affected by urbanization and urban wet weather discharges. The levels, reservoirs and sources of microbiological contamination of the aquatic environment should be assessed and identified, and their impact on the spread of pathogenic bacteria and the risk of exposure of human populations understood. Among the pathogens found in water environments, Pseudomonas aeruginosa is of major health concern. From two experimental sites, the objectives of this work were to define the contribution of wastewater discharges on the prevalence of P. aeruginosa in receiving watercourses and study the ecology of the introduced forms, including their spatiotemporal dynamic and preferential habitats. Sediments, surface biofilms (periphyton) and the submerged aquatic vegetations appeared to favour the survival or growth of some genotypes of Pseudomonas aeruginosa. The distribution of fecal indicator bacteria and of Aeromonas caviae were also studied. It was highlighted that hydraulic forces, the morpho-dynamics of the river and the seasonal vaiations were determinant factors in the distribution of the analyzed microbial contaminants. The health hazard of the clones found in these systems was estimated through indirect molecular approaches. It was shown that all Pseudomonas aeruginosa strains had a high virulence potential and that some were related to the PA14 and C clones which are spread worldwide and pathogenic

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