Dissertations / Theses: 'Dioxyde de chlore'

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Pipon, Yves. "Diffusion thermique et sous irradiation du chlore dans le dioxyde d'uranium." Phd thesis, Université Claude Bernard - Lyon I, 2006. http://tel.archives-ouvertes.fr/tel-00139707.

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Ce travail concerne l'étude de la migration du 36Cl, produit d'activation, dans le dioxyde d'uranium. Nous avons simulé la présence de 36Cl par l'implantation d'une quantité de 37Cl comparable à la concentration de chlore présente à l'état d'impureté. Afin d'évaluer les propriétés de diffusion du chlore dans le combustible, nous avons procédé à deux types d'expériences :
- l'influence de la température a été étudiée en effectuant des recuits thermiques dans une gamme de température comprise entre 900 et 1300°C ; nous avons montré que le chlore implanté était mobile dès 1000°C et déterminé une énergie d'activation de 4,3 eV ;

- l'influence de l'irradiation par des produits de fission a été étudiée en irradiant les échantillons avec des ions 127I (énergie de 63,5 MeV). Nous avons pu déterminer que la diffusion du chlore implanté sous irradiation et dans la gamme de température 30 – 250°C n'était pas purement athermique. Nous avons calculé un coefficient de diffusion sous irradiation D250 °C de l'ordre de 10^(-14) cm^2s^(-1).
Nous avons montré l'importance des défauts d'implantation et d'irradiation qui constituent notamment des chemins préférentiels pour un transport rapide du chlore. Les calculs ab-initio effectués en complément de l'étude expérimentale montrent que le site préférentiel du chlore est un site substitutionnel. Cela nous permet de penser que le mécanisme de diffusion du chlore est un mécanisme atomique de type Frank-Turnbull ou bien un mécanisme de diffusion par paires « lacune / chlore ».

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Pipon, Yves Moncoffre Nathalie Toulhoat Nelly. "Diffusion thermique et sous irradiation du chlore dans le dioxyde d'uranium." [s.l.] : [s.n.], 2006. http://tel.archives-ouvertes.fr/docs/00/13/97/07/PDF/These_Yves.pdf.

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Behrooz, Eshkiki Rabi. "Valorisation de fibres de papiers récupérés par traitement chimique de délignification : réactivité des pâtes mécaniques et chimiques." Grenoble INPG, 2006. http://www.theses.fr/2006INPG0001.

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Les pâtes recyclées sont constituées de mélanges de pâtes mécanique et chimique dont les fibres se différencient structuralement et chimiquement. L'étude présentée vise à appréhender les facteurs déterminants de la réactivité chimique de ces mélanges avec des réactifs oxydants de blanchiment. Le rapport du taux de lignine sur l'indice Kappa est un bon indice d'oxydabilité de la lignine des pâtes. La valeur obtenue pour la pâte kraft est de 30% inférieure à celle de la pâte mécanique, ce qui s'explique principalement par l'importance des teneurs en fonctions OH phénoliques de la lignine. Ceci a été confirmé par modification chimique (diazométhane et periodate de sodium), par analyse spectroscopique IRFT et RMN 13C et par l'étude de composés modèles de lignine. Une méthode originale et simple d'analyse in situ des fonctions OH phénoliques présentes dans les pâtes a été développée, basée sur la réactivité spécifique du dioxyde de chlore sans interférence avec les autres structures chimiques de la lignine. La méthode a été testée sur des composés modèles de lignine et comparée avec la RMN 13C. Les évolutions des teneurs en OH phénoliques sur des pâtes traitées par des agents de blanchiment ont été comparées, ainsi que les effets des stades alcalins. Les résultats obtenus confortent en général les mécanismes réactionnels présentés dans la littérature. En complément, une méthode d'analyse in situ des fonctions quinones a été développée, fondée sur le dosage dès OH phénoliques après réduction des quinones. Les résultats obtenus recoupent assez bien les données d'analyse par RMN 31 P, seule méthode comparative permettant de situer un ordre de grandeur de ces fonctions
Recycled pulps fibres originate from mechanical and chemical pulps mixtures and exhibit important structural and chemical differences. The study herein reported aims at determining significant factors that affect the chemical reactivity of recycled pulps with oxidizing bleaching agents. It was found that the ratio between lignin content and kappa number of pulps was a good oxidability index. The kraft pulp value was 30% lower than the mechanical pulp value. This was imparted to the important role played by phenolic OH groups in lignins. A confirmation of this was obtained by chemical modification of lignin using sodium periodate and diazomethane, by spectroscopic analysis using FTIR and 13C NMR, and by studies on lignin model compounds. Then, an original and simple method was developed for the analysis of the phenolic OH groups in pulps without lignin extraction, so-called in situ analysis. It is based on the selective reaction of chlorine dioxide with phenolic OH groups without action on other structures. The method was successfully compared to 13C NMR analysis. The effects of oxidizing bleaching reagents such as C102, C12, 02, 03, and alkaline treatments were also evaluated. The results were in general accordance with the reaction mechanisms presented in the literature. Furthermore, a chemical method for the analysis of quinone groups in lignins was also developed, based on the in situ analysis of phenolic OH groups after quinones reduction. The results could be successfully compared with 31 P NMR spectroscopic analysis, the only available method to estimate an order of magnitude of quinone groups in lignins

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Barillot, Emmanuel. "Structures de Turing dans les systèmes chlorite-iodure-acide malonique et dioxyde de chlore-iode-acide malonique : études théoriques et modélisation numérique." Bordeaux 1, 1996. http://www.theses.fr/1996BOR10675.

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Nous presentons un ensemble d'etudes theoriques, fondees sur des calculs analytiques et des simulations numeriques, afin d'interpreter les recentes experiences sur les structures de turing, menees avec la reaction dioxyde de chlore-iode-acide malonique. Ces etudes sont notamment fondees sur l'adaptation du modele de lengyel & epstein aux conditions experimentales et son exploitation pour la construction de diagrammes d'etat. Les proprietes tridimensionnelles des structures sont discutees. Nous proposons ensuite une interpretation des structures de turing a symetrie triangulaire apparente, recemment observees. Enfin, nous presentons une approche des phenomenes ondulatoires dans les systemes de reaction-diffusion fondee sur une analyse de l'instabilite k-hopf pour une classe de modeles concus a cette fin et dont la simulation numerique a suscite la realisation d'une nouvelle methode spectrale particulierement bien adaptee a la representation des dynamiques de phase

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Dausseins, Julie. "Étude du comportement à long terme d'accessoires en polyamide 66 utilisés dans les réseaux d'eau intérieurs." Thesis, Paris, ENSAM, 2015. http://www.theses.fr/2015ENAM0017/document.

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Le dioxyde de chlore se positionne actuellement comme une alternative au chlore pour la désinfection de l'eau potable. Bien que son pouvoir biocide soit aujourd'hui bien connu, il existe peu de données bibliographiques sur ses effets sur les matériaux organiques dans les réseaux d'eau intérieurs. L'utilisation du PA66 pour des clapets anti-retour est récente : son comportement à long terme est donc méconnu. L'objectif de cette étude était de progresser dans la compréhension des mécanismes d'interaction entre le dioxyde de chlore et une matrice PA66 stabilisée par un mélange de deux antioxydants et chargée de fibres de verre, mais aussi de proposer une méthode « multi-échelle » de prédiction de la durée de vie de ce matériau composite en service. Tout d'abord, une meilleure description des réactions chimiques se produisant au sein du matériau (oxydation, hydrolyse, protection du polymère par les antioxydants, attaque chimique du polymère et des antioxydants par le désinfectant) a permis d'élaborer un schéma mécanistique général de dégradation. Des équations cinétiques ont été dérivées de ce schéma mécanistique pour prédire l'évolution des modifications chimiques, en considérant une répartition hétérogène des antioxydants dans la matrice PA66 et en prenant en compte la plupart des conditions d'exposition (température de l'eau, concentration en réactifs chimiques, temps). Ensuite, le matériau vieilli a été testé en conditions d'usage grâce à des essais de pression hydrostatique pour identifier son régime de rupture
Nowadays, chlorine dioxide is an alternative of chlorine for the disinfection of drinking water. Although its biocide ability is well known, scientific literature lacks of knowledge about its effects on organic materials in domestic water networks. The use of PA 66 for valves is quite recent: its long term behaviour is thus unknown. The aim of this study was to improve the knowledge of the interaction mechanisms between chlorine dioxide and a PA 66 matrix stabilized by blend of two antioxidants and reinforced by glass fibres, but also to propose a multi-scale method for the lifetime prediction of this composite material in service. First of all, a better description of the chemical reactions occurring within the material (oxidation, hydrolysis, polymer protection by antioxidants, chemical attack of polymer and antioxidants by disinfectant) has allowed elaborating a general degradation mechanistic scheme. Kinetic equations were derived from this mechanistic scheme for predicting the chemical changes, considering a heterogeneous distribution of antioxidants within the PA 66 matrix and taking into account most exposure conditions (water temperature, concentration in chemical reactants, time). Then, the aged material was tested in use conditions thanks to hydrostatic pressure experiments in order to identify its failure regime

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Mortha, Gérard. "Contribution à l'étude du blanchiment des pâtes cellulosiques par le dioxyde de chlore dans un réacteur agité à alimentation progressive." Grenoble INPG, 1989. http://www.theses.fr/1989INPG0039.

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L'etude du blanchiment des pates cellulosiques par le dioxyde de chlore est effectuee dans un reacteur agite a alimentation progressive. Un tel reacteur permet de controler les principaux parametres de la reaction: ph, temperature, agitation de la suspension, et de preciser les conditions de formation des especes minerales intermediaires et la stchiometrie des reactions correspondantes. Il est apparu que le ph, en particulier, joue un role predominant tant sur la stchiometrie de formation des ions chlorite et chlorure que sur la reactivite du dioxyde de chlore avec la lignine, dont depend le taux de formation de chlorate lors du blanchiment par le dioxyde de chlore. Le mecanisme etudie a conduit a la definition d'une nouvelle procedure de blanchiment en un seul stade (d), permettant d'atteindre les caracteristiques obtenues lors du blanchiment classique en trois stades )d-e-d), et reduisant de trente pour cent la consommation de dioxyde de chlore du fait d'une production de chlorate cinq fois plus faible, ce qui entraine une reduction de la pollution. Sur la base d'une etude cinetique, une modelisation complete de cette procedure a ete determinee

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Zaragoza, Robert. "Application des fluides supercritiques à l'extraction de composes organochlorés dans des matrices de type sol." Lyon, INSA, 1993. http://www.theses.fr/1993ISAL0087.

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L'extraction par fluide supercritique (fluide extractant C02 ou C02 modifié) est effectuée sur des échantillons de sols (EUROSOILS) témoins pollués par des composé anochlorés de diverses polarités. Un micropilote de laboratoire et des extracteurs commercialisés sont décrits, les divers paramètres influençant 1 'extraction sont énoncés. Une première étape de 1'étude est consacrée à l(étude de la faisabilité de 1 'extraction de polluants organochlorés (Pyralène Tl (fluide diélectrique de transformateurs) et chlorophénols) en présence de C02 supercritique pur ou dopé avec des modificateurs polaires. La deuxième étape optimise les conditions d'extraction des polluants (Pyralène Tl ; 2,4,6- trichlorophénol et aldrine). Une étude systématique de l'extraction est conçue et interprétée selon la méthodologie des plans d'expériences. Les paramètres physiques pris en compte sont les pressions, température, débit d'extraction. Nature du fluide extractant, teneur en eau, durée de 1a phase statistique et masse de sol. Des modèles mathématiques associés au rendement d'extraction ont été établis à partir de cette méthodologie. L'extraction par fluide supercritique est une technique compétitive et viable à l'échelle du laboratoire et présente un grand intérêt pour le traitement futur de sols contaminés
Supercritical fluid extraction using C02 or modified C02 is reported for standard sail samples (EUROSOIL) polluted by organochlorinated compounds of different polarities. A laboratory scale and sorme commercialized extractors are described and the various parameters influencing extraction are presented The first step of the study has consisted in a feasibility extraction study of organochlorinated pollutants (Pyralène Tl : dielectric fluid transformer, and chlorophenol) using supercritical C02 either pure or spiked with polar cosolvent. The second step optimizes the extraction conditions of the pollutants (Pyralêne T1 : 2,4,6 - trichlorophenol and aldrin). A systematic extraction study is developed and interpreted according to the methodology of experimental design, physical parameters chosen were pressure, temperature extraction flow-rate, type of extractant fluid. Water content, duration of static phase and weight of soils. Mathematical of extraction yields have been established according ta this methodology Supercritical fluid extraction is a competitive and viable technique at laboratory sca1e and shows great promises for future treatment of contaminated soils

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Rudovics, Be'ata. "Structures stationnaires de Turing et ondes dans les systèmes chlorite-iodure-acide malonique et dioxyde de chlore-iode-acide malonique : motifs et transitions." Bordeaux 1, 1995. http://www.theses.fr/1995BOR10596.

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Le couplage entre la reaction chimique non lineaire et le transport par diffusion moleculaire des especes mises en jeu peut conduire a des phenomenes d'auto-organisation spatiale. Il en resulte des repartitions periodiques des concentrations des especes sous la forme de motifs stationnaires (instabilite de turing) ou de motifs dependant du temps (instabilite de hopf). Nous decrivons differents types de motifs stationnaires de turing (bi-et tridimensionnelles) ainsi que les dynamiques resultant de l'interaction entre les instabilites de turing et de hopf. Nous presentons egalement un nouveau mode de croissance des structures stationnaires par division. Nous abordons aussi une etude quantitative de la diffusion effective d'especes solvatees pouvant former des complexes reversibles avec des especes de mobilite reduite. Nous determinons le role de cette complexation sur les instabilites de turing et de hopf

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Joncourt, Pitzini Marie-Jeanne. "Possibilités de réduction des composés organochlorés formés au cours d'un stade de blanchiment par le dioxyde de chlore." Grenoble INPG, 1996. http://www.theses.fr/1996INPG0096.

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L'objectif de ce travail est d'etudier la possibilite de reduction des composes organochlores formes au cours d'un stade de blanchiment de la pate a papier au dioxyde de chlore. Les reactions du dioxyde de chlore et de la lignine formant du chlore comme produit intermediaire, nous avons dans un premier temps etudie le role et la participation du chlore (acide hypochloreux) et du dioxyde de chlore a la delignification et a la formation des composes organochlores. Parallelement nous avons developpe une methode de dosage des composes mineraux chlores par electrophorese capillaire. Cette technique presente l'avantage de temps d'analyse tres courts sans traitement prealable des echantillons. Nous avons ensuite etudie les possibilites de reduction des composes organochlores en ajoutant un additif: acide sulfamique, peroxyde d'hydrogene ou dimethylsulfoxyde pour capter le chlore (acide hypochloreux) des son apparition dans le milieu. En milieu tres acide, avec une charge en additif de 1% pate la reduction se situe entre 30 et 40%. La suppression du chlore (acide hypochloreux) s'accompagne d'une baisse de la delignification. La viscosite de la pate chute avec certains additifs s'ils sont utilises a forte concentration

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Clavelin, Pierre. "Contribution à l’étude de la pollution des sols par des composés organochlorés : : préparation de mélanges témoins - : Etude comparative de techniques d'extraction." Lyon, INSA, 1993. http://www.theses.fr/1993ISAL0088.

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Dans un premier temps, nous avons cherché à mettre au point un protocole de préparation de mélanges secs ou humides, composés d'une matrice de type-sol (argile pure, sols réels) contaminée de façon homogène par un polluant organochloré (pyralène Tl, chlorophénols). En plus de l'aspect homogénéité, nous avons cherché à savoir si ce protocole permettait d'obtenir une adsorption du polluant sur l'adsorbant. A l'issue de cette étude, nous proposons une méthodologie (utilisant un évaporateur rotatif) satisfaisant au critère d'homogénéité. Cependant, nous montrons que des pertes en polluant surviennent et que, pour les mélanges secs ainsi préparés, le polluant n'est pas adsorbé, mais simplement déposé. Nous mettons également en évidence le rôle de l'eau, favorisant l'adsorption. Dans un second temps, à partir de ces mélanges synthétiques, nous comparons les performances de quatre types de techniques d'extraction : par voie thermique (microsublimation, désorption thermique, pyro-injection), par solvants organiques liquides (Soxhlet, Soxtec), par dioxyde de carbone (liquide, gaz et supercritique) et par percolation à l'eau (pour différentes conditions de température et de pression). De bons rendements d'extraction sont obtenus avec les techniques combinant température et/ou pression (micro sublimation) et un solvant (eau, dioxyde de carbone ou solvant organique). Comme pour l'adsorption, la présence d'eau influe sur la qualité de la désorption
In a first step, we have tried to prepare dry or humidified mixtures composed with clays or real soils homogeneously spiked by organochlorine pollutants (Pyralène Tl, chlorophenols). Beyond the homogeneity aspect, we wanted to know if the preparation procedure allow to obtain pollutant adsorption on the absorbent. Finally we propose a protocol (with a rotary evaporator) satisfying the homogeneity critter. However, we observe some pollutant losses and we show that, for dry mixtures, the pollutant is not adsorbed but only coats soil particles. We demonstrate the water effect on adsorption. In a second step, with these synthetic mixtures, we compared the efficiency of four types of extraction techniques: thermal way (micro sublimation, thermal desorption, pyro-injection), by liquid organic solvents (Soxhlet, Soxtec), by carbon dioxide (liquid, gas or supercritical) and by water leaching (at various temperature and pression conditions). Good recoveries are found with techniques using temperature and/or pressure (micro-sublimation) an and an solvent (water, carbon dioxide or organic solvent). As well as adsorption, water influences desorption quality

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Aiteh, Hassan al. "Formation, structure et limites de detonation dans le bioxyde de chlore et dans l'azoture d'hydrogene." Paris 6, 1988. http://www.theses.fr/1988PA066624.

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Marcon, Jennifer. "Pâtes lignocellulosiques : étude d'un nouveau stade de blanchiment ECF à faible impact environnemental." Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAI104.

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Le dioxyde de chlore est l’agent de blanchiment le plus utilisé pour le blanchiment des pâtes chimiques lignocellulosiques. Son utilisation s’accompagne malheureusement de la formation d’ions chlorates, composés inefficaces pour le blanchiment, ainsi que d’importants rejets de DCO et d’organo-chlorés (AOX), nuisibles pour l’environnement. Cette étude a consisté à concevoir un nouveau stade de blanchiment au dioxyde de chlore (stade D) à pH non-conventionnel, économe en réactifs, et visant à réduire l’impact environnemental d’une séquence classique. Le travail a été effectué sur des pâtes kraft de résineux, obtenues après cuisson ou à différents stades de la séquence de blanchiment. Les résultats ont montré que l’efficacité du nouveau stade D était meilleure lorsqu’il était placé en fin de séquence. Après optimisation et incorporation de peroxyde d’hydrogène comme réactif complémentaire, les pâtes obtenues présentent des caractéristiques équivalentes à celles d’un blanchiment conventionnel, en termes de blancheur et de degré de polymérisation moyen viscosimétrique ; et ce, avec une réduction drastique de la pollution (70% des AOX et 20 % de DCO), et un gain économique substantiel en productivité de séquence (diminution de la température et du temps de réaction). L’étude chimique de la réaction du dioxyde de chlore effectuée par différentes techniques (spectroscopie RPE, RMN, FTIR, chromatographie HPAEC-PAD), a révélé la présence de radicaux hydroxyles en milieu alcalin, et mis en évidence les principales étapes du mécanisme à différents pH
Chlorine dioxide is the most widely used bleaching agent for the production of bleached chemical pulps. However, its main drawbacks are the formation of chlorate ions which decrease delignification efficiency and the reject of toxic chloro-organic molecules (AOX) in mill effluents. This study focused on the development of a new bleaching stage using chlorine dioxide (D stage) at non-conventional pH, to reduce environmental impact and production costs. The work was carried out on several softwood kraft pulps after cooking, and at different stages of the bleaching sequence. The best results of the novel D stage were obtained for pulps at low kappa number, i.e. at the end of the bleaching sequence. The D stage was optimized and coupled with hydrogen peroxide addition. The same brightness and viscosimetric average degree of polymerization as after conventional D bleaching were obtained. Interestingly, a very important decrease of pollution load (70% of AOX and 20% of COD) was obtained, accompanied by a significant gain of productivity and energy saving (lower temperature and reaction time).Chemical investigations on the reaction mechanisms, carried out by different techniques (ESR, NMR and FTIR spectroscopies, HPAEC-PAD chromatography), revealed the formation of hydroxyl radicals at alkaline pH. The structural modification of the pulp residual lignin was also studied; differences of the reaction mechanism as function of pH were highlighted

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El, mazry Chaker. "Durabilité de produits innovants de robinetterie en polyamide 6,6." Phd thesis, Paris, ENSAM, 2013. http://pastel.archives-ouvertes.fr/pastel-00871827.

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Le PA 6,6 est maintenant envisagé pour des pièces de robinetterie sur le réseau domestique de distribution d'eau potable. Cependant, ce matériau ne pourra être utilisé que si sa durabilité à long terme, en conditions réelles de service, est clairement démontrée. L'analyse cinétique des principaux mécanismes de vieillissement chimique susceptibles de se produire et d'interagir sur le réseau domestique de distribution d'eau potable : l'hydrolyse, la thermo-oxydation et l'attaque chimique par le dioxyde de chlore, a permis au final d'élaborer un modèle cinétique général de dégradation du PA 6,6. Ce modèle donne accès aux modifications structurales du PA 6,6 aux différentes échelles pertinentes (moléculaire, macromoléculaire, morphologique et macroscopique) en conditions de service. Il prédit la fragilisation du PA 6,6 lorsque la masse molaire moyenne en nombre atteint une valeur critique de l'ordre de 17 kg/mole. De nombreuses perspectives de recherche sont présentées comme l'introduction de ce modèle cinétique dans les codes courants de calcul mécaniques.

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Desai, Unmesh Jeetendra. "Comparative Analytical Methods for the Measurment of Chlorine Dioxide." Thesis, Virginia Tech, 2002. http://hdl.handle.net/10919/34134.

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Four commercially available methods used for the analysis of low-level Chlorine Dioxide (ClO2) concentrations in drinking water were evaluated for accuracy and precision and ranked according to cost, efficiency and ease of the methods under several conditions that might be encountered at water treatment plants. The different analytical methods included: 1.The DPD (N, N-diethyl-p-phenylenediamine) method 2.Lissamine Green B (LGB) wet-chemical method 3.PalintestÂ® kit LGB 4.Amperometric titration All these tests were performed with standard 1.0 mg/L ClO2 either alone or in the presence of different chlorine species, including chlorite ion (ClO2-, 0.5 mg/L), chlorate ion (ClO3-, 0.5 mg/L) and chlorine (Cl2, 1.0 mg/L). The tests were performed with four different matrices, with different concentrations of 0.1 mg/L ClO2, 0.5 mg/L ClO2 and 1.0 mg/L ClO2 at a constant temperature of 20oC and at different temperatures of 0oC, 10oC and 20oC at a fixed ClO2 concentration of 1.0 mg/L. None of the four methods produced the desired level of either accuracy or precision. For all four methods, interference to the measured ClO2 concentration from the addition of ClO2-, ClO3-, and Cl2 was minimal when the methods were performed according to specifications. The PalintestÂ® was the best all-round method because it was easy to perform, performed well at all concentrations tested, and its colored product was stable. The HACHÂ® DPD method was also easy to perform and gave the best results when measuring concentrations of 1.0 mg/L ClO2. The DPD method was less accurate than the PalintestÂ® at lower concentrations. The DPD colored product that formed upon reaction of ClO2 and DPD was unstable, making it necessary to measure the intensity of the colored product at exactly 1 minute. The amperometric titration and lissamine green methods were more cumbersome and time-consuming to perform than either the DPD or PalintestÂ® methods; for this reason they are less desirable for routine use.
Master of Science

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Bernachot, Isabelle. "Utilisation des isotopes stables du chlore pour le traçage des processus générés par l'injection de CO2 au sein d'un réservoir géologique." Thesis, Sorbonne Paris Cité, 2017. http://www.theses.fr/2017USPCC016/document.

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L’injection de CO2 dans un réservoir géologique n’a rien d’un processus anodin : les impacts sur la roche hôte peuvent menacer l’intégrité du stockage suite à des modifications des propriétés pétrophysiques. Nous proposons ainsi d’envisager l’utilisation des isotopes stables du chlore comme indicateurs des processus physicochimiques générés par une injection de CO2. L’ion chlorure Cl- est en effet un élément conservatif et ubiquiste dans les eaux des réservoirs, et le rapport δ37Cl est connu pour être modifié par divers processus (diffusion, filtration ionique, précipitation de sel, changements de phase). La méthodologie adoptée a consisté à investiguer les effets de ces différents processus sur le signal isotopique du Cl en conditions P-T d’un réservoir de stockage. Des expériences en autoclaves ont montré que le Cl était solubilisé dans le CO2sc, mais en quantités suffisamment faibles pour ne pas impacter le signal isotopique dans les saumures si fractionnement isotopique il y a. Des expériences de migration d’une saumure réactive par advection (banc de percolation ICARE1, Université de Montpellier) et par diffusion (cellule développée à IFPEN) ont également été réalisées. Aucune évolution de δ37Cl n’a été mesurée au cours de la percolation (transport advectif conservatif) et les effets de la diffusion restent à évaluer et à mettre en relation avec les évolutions de porosité et perméabilité des roches. Les expériences de séchage et de précipitation de sel en milieu poreux ont montré que les concentrations en Cl et les valeurs de δ37Cl permettaient de caractériser les processus de transport en jeu. Ces résultats expérimentaux ont permis d’identifier des processus capables de modifier les abondances isotopiques de Cl et indiquent l’intérêt des isotopes pour le monitoring de site de stockage de CO2
CO2 injection in a reservoir leads to physicochemical processes which can have harmful consequences on the reservoir integrity due to porosity and permeability alteration. In this work, we propose to test the possibility that stable chlorine isotopes could be used as a geochemical tool to assess these effects. Indeed, chloride is a conservative and a major component of reservoir brines, and it is already known that several processes can modify the ratio of its two stable isotopes δ37Cl (diffusion, ionic filtration, salt precipitation or phase change). To test this possibility, several types of experiments were performed to investigate the effects generated by a CO2 injection on Cl-isotopes. Autoclave experiments have shown that Cl can be solubilized in CO2SC, but the amounts would be too low to modify the isotopic signal of brines in case of any fractionation process. Reactive brine migration experiments by advection (ICARE1 percolation apparatus in Montpellier University) and diffusion (diffusion cell developed at IFPEN) were also conducted. No δ37Cl was observed during percolation (conservative advective transport) and the effects of diffusion remain to be investigated with regard to the evolution of rock porosity and permeability. Drying and salt precipitation experiments on porous media have shown that Cl concentrations and δ37Cl values can give information about transport processes during water evaporation. These experimental results allowed us to identify the processes capable of modifying the δ37Cl signal, and that Cl-isotopes can be of use for the monitoring of CO2 storage site

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16

Ben, Amor Hedi. "Le bioxyde de chlore dans la filière de production des eaux de consommation : contribution à l'étude de son mécanisme d'action sur les molécules modèles et sur les substances humiques aquatiques." Poitiers, 1988. http://www.theses.fr/1988POIT2314.

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17

Ellenberger, Christine Spada. "Water Quality Impacts of Pure Chlorine Dioxide Pretreatment at the Roanoke County (Virginia) Water Treatment Plant." Thesis, Virginia Tech, 1999. http://hdl.handle.net/10919/30807.

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Chlorine dioxide (ClO₂) was included in the Spring Hollow Water Treatment Plant (Roanoke County, Virginia) to oxidize manganese and iron, prevent tastes and odors, and avoid the formation of excessive halogenated disinfection by-products. A state-of-the-art, gas:solid ClO₂ generation system manufactured by CDG Technology, Inc. was installed at the plant and is the first full-scale use of this technology in the world. The ClO₂ generator produces a feed stream free of chlorine, chlorite ion (ClO₂⁻), and chlorate ion (ClO₃⁻), resulting in lower by-product concentrations in the treatment system The objectives of this project were to study ClO₂ persistence and by-product concentrations throughout the treatment plant and distribution system and to evaluate granular activated carbon (GAC) columns for removing ClO₂⁻ from the finished water. The ClO₂ dosages applied during this study were relatively low (<0.75 mg/L), and, as a result, ClO₂⁻ concentrations never approached the maximum contaminant level (MCL) (1.0 mg/L). Likewise, the plant effluent ClO₂ concentration never approached the maximum residual disinfectant level (MRDL) (0.80 mg/L), but concentrations as high as 0.15 mg/L reformed in the distribution system by ClO₂⁻ reaction with chlorine. Chlorate ion was monitored despite the fact that no ClO₃⁻ MCL has been proposed, and concentrations were quite low (never greater than 0.10 mg/L) throughout the treatment plant and in the distribution system. The reasons for the low concentrations are that ClO₃⁻ is not produced by the gas-solid generator used at the facility and ClO₂⁻ concentrations in the clearwell prior to chlorination were uniformly low. The average ClO₂⁻ reduction upon passage of treated water through the GAC contactor was approximately 64 percent, but the GAC effectiveness was declining over the six-month study period. Apparently, GAC effectiveness, as shown by others, is short-lived, and if higher ClO₂ dosages are ever applied at the Roanoke County facility, the ClO₂⁻ concentrations will have to be reduced by either ferrous coagulants or reduced-sulfur compounds. Regenerated ClO₂ concentrations in the distribution system were below 0.2 mg/L, but concentrations as low as 0.03 mg/L were found at homes of customers who complained of odors. During this study, twelve complaints were received from eight customers, and each complainant had recently installed new carpeting, which has been shown to contribute volatile organics that react with ClO₂ to produce odors similar to kerosene and cat urine. While meeting the Cl₂ MCL likely will be no problem if the ClO₂ dose at the plant remains below 1.0 mg/L, the problem of offensive odors in the distribution system will likely continue as long as any ClO₂ is in the finished water when chlorine is present.
Master of Science

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18

Trinh, Thanh. "Contribution à l'étude de la délignification et du blanchiment des pâtes cellulosiques par le bioxyde de chlore ou l'eau oxygénée dans un réacteur agité à alimentation programmée." Grenoble INPG, 1993. http://www.theses.fr/1993INPG0100.

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Cette these est consacree a l'etude de la delignification des pates cellulosiques par le bioxyde de chlore ou l'eau oxygenee dans le but d'ameliorer la selectivite de ces reactifs et de minimiser les rejets toxiques. L'etude comparative de la delignification et du blanchiment par le bioxyde de chlore montre que la phase d constituee des sous-phases: introduction progressive de clo#2 en milieu alcalin (ph10) et reaction en milieu acide (ph4,7) du chlorite precedemment forme est le meilleur procede. La cinetique de la reaction limitante de ce procede (sous-phase acide, reaction du chlorite) est etudiee par la suite. L'influence du ph, des catalyseurs ainsi que celles des stabilisants et complexants sur la cinetique de decomposition de h#2o#2 est etudiee. La complexite du phenomene conduit a la modelisation des cinetiques. Le modele propose (somme d'une cinetique d'ordre 1 et d'ordre 2) est teste dans un large domaine experimental dans les conditions du blanchiment et montre le role particulierement complexe des ions metalliques (fe) apportes par les reactifs. Cependant en regroupant les experiences suivant des criteres d'impuretes apportees par la soude, la modelisation conduit a des resultats tres satisfaisants qui permettent de valider le modele. L'etude de la cinetique de delignification et du blanchiment par h#2o#2 d'une pate ecrue de resineux, d'une pate preblanchie ce et des pates ecrues ayant subi un pretraitement acide est abordee. Elle permet d'attribuer a la reaction un ordre 1 par rapport a l'eau oxygenee et conduit a proposer un processus de blanchiment certes plus long mais dont la selectivite est amelioree

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19

Burke, Michael A. "Kinetics of the chlorate-hydrogen peroxide reaction in the formation of chlorine dioxide." Thesis, Georgia Institute of Technology, 1993. http://hdl.handle.net/1853/11817.

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20

Indu, Bhart. "Kinetics and mechanism of methanol-chlorate reaction in the formation of chlorine dioxide." Diss., Georgia Institute of Technology, 1993. http://hdl.handle.net/1853/10956.

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21

Mavu, Daniel Muleya. "Pharmaceutical formulation and in-vitro testing of Dioxy MP 14 (stabilised chlorine dioxide) against mycobacteria tuberculosis." University of the Western Cape, 2011. http://hdl.handle.net/11394/5372.

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Magister Pharmaceuticae - MPharm
This study was based on Dioxy MP 14 (DMP), a brand of stabilized chlorine dioxide (SCD). The active pharmaceutical ingredient (API) of DMP is chlorine dioxide (CD) which is a potent oxidant and biocide. These properties have proved invaluable for various applications. The main goals of this study were: to evaluate the effectiveness of DMP for disinfecting Mycobateria tuberculosis (TB) contaminated medical instruments, devices, floors and surfaces; to investigate the stability of DMP; and to explore possibilities for medical application of DMP. Evaluation of disinfectant activity of DMP on TB was performed using the spectrophotometric method, a modification of the European suspension test, EN 14348. M. bovis BCG was employed as surrogate in this test. Results were as follows: The minimum inhibitory concentration (MIC₉₀) = 12.5 ppm; the minimum bactericidal concentration (MBC) = 15.4 ppm; the Mycobactericidal Effect (ME) = 8.8log reduction; and the minimum inhibitory concentration (MIC₉₀) x minimum exposure time (CT) = 12.5 ppm.s. The long term stability study of DMP was performed by monitoring the rate of degradation of DMP stored in the fridge (2-8 °C), in the oven (40 °C), and under ambient conditions (15-30 °C). Analytical methods of assessing DMP concentration was by Iodometric titration method. The shelf life of DMP stored in a transparent bottle at room temperature was 9.8 weeks, as opposed to 52.7 weeks when stored in an amber colored reagent bottle at the same temperature. Both oven samples had an expiry date of about 20 weeks and the fridge samples about 70 weeks. Foam formulations for a vaginal douche (VGD), mouth rinse (MRF), and foot/sit bubble bath (F/SBB)], were developed in the laboratory. DMP and the formulated concentrate were designed to be mixed just prior to administration. During foam evaluation studies, a mechanical overhead stirrer was used to generate foam. Foamability was assessed by quantifying the amount of foam generated. The stability of foams were assessed by: 1) determining the rate of foam decay and the rate of foam drainage observed concurrently from foam loaded in a measuring cylinder; and 2) determining the life span of single bubbles of each foam system i.e. the bubble breaking time (BBT). The density of each foam system was also determined. Potentiometric acid base titration was used to select suitable adjuster alkali, and to show the benefits of employing a buffer. Concentrate development was initiated by a simple mixture of all the ingredients followed by stirring and observing the deviations from desired quality attributes of the product. The subsequent five processes were improvements designed to circumvent the shortcomings of the initial procedure to arrive at the optimized method E. Prototype formulations were employed to optimize excipient quantities to eventually arrive at an optimized master formula. In foam evaluation, it was found that sodium lauryl sulphate/ammonium lauryl sulphate/cocoamidopropyl betaine/cetostearyl alcohol (SLS/ALS/CAPB/CSA) foam system was the most appropriate to use in the formulation. NaOH was selected as the adjuster solution and KHP as the buffer. The dosage formula (DF) of the VGD and F/SBB was determined to be MDF = 5 ml of 50 ppm DMP + 5 ml concentrate + 40 ml water = 50 ml and that of MRF as MDF = 19 ml diluted concentrate + 1 ml of 50 ppm DMP. In conclusion, DMP was found to be a highly effective disinfectant against Mycobacteria. DMP has reasonable shelf life if stored appropriately. Pharmaceutical formulation from DMP was found to be delicate due to the narrow pH window of DMP stability, but is feasible.

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22

Hall, Sarah W. "The generation of chlorine dioxide from the reaction between sodium chlorite and acetic anhydride." Thesis, Anglia Ruskin University, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.427477.

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23

Nyholm, Bethany Paige. "Resonance Raman intensity analysis of chlorine dioxide, nitrosyl chloride, and isopropyl nitrate in solution /." Thesis, Connect to this title online; UW restricted, 2003. http://hdl.handle.net/1773/8496.

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24

Crump, Brian R. "Kinetic study of the mechanism and side reactions in the hydrogen peroxide based production of chlorine dioxide." Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/11322.

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25

Cosson, Herve. "Photodecomposition of chlorine dioxide and sodium chlorite in aqueous solution by irradiation with ultraviolet light." Thesis, Georgia Institute of Technology, 1993. http://hdl.handle.net/1853/11177.

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26

BOURGEOIS, CHARIGOT MARIE-THERESE. "Diffusion raman resonnante et structure des etats moleculaires excites." Reims, 1988. http://www.theses.fr/1988REIMS013.

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Des modeles d'etude sont proposes et appliques a differentes especes moleculaires. Les modeles suivants, de complexite croissante, sont presentes: approximation de reflexion, approximation harmonique, potentiels de morse, modele analytique tridimensionnel incluant l'effet duschinsky. Ce dernier modele est applique au cas de l'ozone et etendu ensuite aux molecules rendues non symetriques par une substitution isotopique

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27

Foster, Catherine. "Resonance raman intensity analysis of chlorine dioxide in solution /." Thesis, Connect to this title online; UW restricted, 2000. http://hdl.handle.net/1773/11595.

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28

Leahy, Joseph Gerard. "Inactivation of Giardia muris cysts by chlorine and chlorine dioxide." The Ohio State University, 1985. http://rave.ohiolink.edu/etdc/view?acc_num=osu1345744018.

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29

Körtvélyesi, Zsolt. "Analytical Methods for the Measurement of Chlorine Dioxide and Related Oxychlorine Species in Aqueous Solution." Miami University / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=miami1088030135.

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30

Philpott, Matthew Perry. "Time-resolved resonance Raman and femtosecond pump-probe study of chlorine dioxide (OClO) photochemistry in solution /." Thesis, Connect to this title online; UW restricted, 2000. http://hdl.handle.net/1773/8555.

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31

Tenney, Joel David. "The kinetics of the chlorine dioxide generation reaction." Thesis, Georgia Institute of Technology, 1988. http://hdl.handle.net/1853/10020.

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32

Stedl, Todd Robert. "Computational investigations of the dynamics of chlorine dioxide /." Thesis, Connect to this title online; UW restricted, 2003. http://hdl.handle.net/1773/8497.

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33

West, Richard Henry. "Modelling the chloride process for titanium dioxide synthesis." Thesis, University of Cambridge, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.611241.

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34

Hayes, Sophia Charalambous. "Chlorine dioxide photochemistry in solution : time-resolved resonance Raman and femtosecond pump-probe studies /." Thesis, Connect to this title online; UW restricted, 2001. http://hdl.handle.net/1773/11614.

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35

Buffin, Lisa Webster. "Treatment of algae-induced tastes and odors by chlorine, chlorine dioxide and permanganate." Thesis, Virginia Tech, 1992. http://hdl.handle.net/10919/42612.

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Chlorine (C12(sqÂ»' chlorine dioxide (Cl02 ) and potassium permanganate (KMn04) were evaluated as oxidants for the removal of grassy and cucumber odors associated with the pure compounds, cis-3-hexenol and trans-2, cis-6-nonadienal, respectively, and for the removal of fishy odors associated with a culture of an alga, Synura petersenii. The effects of the oxidants on the pure compounds were assessed both by Flavor Profile Analysis (FPA) and gas chromatography/mass spectrometry (GC/MS). The effects of the oxidants on the algae culture were evaluated by FPA only. In addition, an unoxidized sample of Synura petersenii was analyzed by gas chromatography coupled with mass spectrometry (GC/MS) for possible identification of fishy-smelling compounds. Chlorine (1-6 mg/L) and KMn04 (0.25-4 mg/L) markedly reduced grassy and cucumber odors associated with the two compounds. Gas chromatography/mass spectrometry confirmed that these compounds were reduced to below method detection limits. Levels of C12(&q) required (up to 6 mg/L) to reduce the grassy odors associated with cis-3-hexenol were higher than those of KMno4 â ¢ The high C12(&q) doses may have contributed to the formation of chemical odors observed by panelists. Two isomers of chlorohexenol were confidently identified as byproducts of cis-3-hexenol chlorination and may have contributed to the chemical odors that developed after CI2(aq) treatment. Chlorine and KMn04 (both at 10 mg/L) either reduced or destroyed the fishy odor associated with the culture of Synura petersenii; however, oxidation caused either the development or unmasking of fruity, cucumber, melon and grassy odors. Chlorine dioxide (3 mg/L) did not reduce the grassy and cucumber odors associated with cis-3-hexenol and trans-2, cis-6-nonadienal , respectively. Gas chromatography and mass spectrometry confirmed that concentrations of these compounds were not reduced to below method detection limits. Furthermore, at a concentration of 10 mg/L, CI02 did not effectively reduce either the fishy or other objectionable odors associated with Synura petersenii culture. Hexanal, with an odor described as "green" or "like lettuce heart," and trans-2, cis-6-nonadienal (cucumber odor) were confirmed as algal products in a two-week-old culture of Synura petersenii. In addition, decatrienal was confidently identified as a product of Synura and may have contributed to the fishy odor associated with this alga.
Master of Science

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36

Liyanage, Lalith R. J. "Chlorine dioxide inactivation of Cryptosporidium parvum oocysts in water." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0007/NQ29064.pdf.

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37

Powis, Samantha. "Chlorine Dioxide for the Prevention of Biomaterial-Associated Infections." Diss., Tucson, Arizona : University of Arizona, 2005. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu%5Fetd%5F1307%5F1%5Fm.pdf&type=application/pdf.

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38

Ferreira, Francisco Cardoso. "Chlorine dioxide and by-products in water distribution systems." Thesis, This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-11242009-020052/.

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39

Alcalá, Borao Raquel. "Oxidation of pharmaceuticals by chlorine dioxide in wastewater effluent." Thesis, KTH, Mark- och vattenteknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-171862.

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The presence of pharmaceuticals in the environment has raised an emerging interest due to the fact that they pose negative environmental impact and health hazards related to long-term toxicity effects. As conventional treatments are not able to totally remove these substances it is necessary to seek for alternative advanced technologies such as oxidation with chlorine dioxide (ClO2). The objective of this master thesis is thus to find the most optimal dose – reaction time of ClO2 for the oxidation and maximum removal of selected environmentally relevant pharmaceuticals. Factorial design and subsequent optimization with MODDE was selected as the best approach to find the optimal dose – time. Batch oxidation tests were conducted on 100mL aliquots treated with ClO2 using wastewater effluent from Henriksdal WWTP. Thereafter solid phase extraction and final determination of pharmaceuticals was carried out on a high performance liquid chromatography- triple quadrupole mass spectrometry (HPLC-MS/MS). Results showed that applying a dose of 5 mg ClO2/L and a reaction time of 10 minutes, it is possible to remove more than a half of the 17 analyzed substances. Besides most of the pharmaceuticals with high and moderate environmental risk, would pose a low risk for the environment after treatment with the optimal ClO2 dose – reaction time. Despite the fact that ClO2 could successfully degrade most environmentally relevant pharmaceuticals, deeper research concerning the formation of toxic by-products after oxidative treatment needs to be done before upscaling this technology to pilot or full scale as a suitable end of pipe technology for pharmaceuticals removal.

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40

DiMascio, Felice. "A novel electrochemical/catalytic process to generate chlorine dioxide." Thesis, University of Bath, 2003. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.425873.

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41

Dring, Kevin Frederick. "Electrochemical reduction of titanium dioxide in molten calcium chloride." Thesis, Imperial College London, 2006. http://hdl.handle.net/10044/1/8135.

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42

Esposito, Anthony Paul. "Resonance Raman studies of halooxide photochemistry in the gas and condensed phase /." Thesis, Connect to this title online; UW restricted, 2001. http://hdl.handle.net/1773/8616.

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43

Dufresne, Laura C. "Destruction of algae-produced taste-and-odor compounds by chlorine, potassium permanganate, and chlorine dioxide." Thesis, This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-11242009-020302/.

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44

Runge, Troy M. "Chemistry of an oxidative alkaline extraction between chlorine dioxide stages." Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/7050.

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45

Ni, Yong. "A fundamental study of chlorine dioxide bleaching of kraft pulp." Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=39405.

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The fundamentals of chlorine dioxide bleaching of softwood kraft pulp are studied by measuring the development of the inorganic chlorine species: chloride, hypochlorous acid, chlorite, chlorine dioxide and chlorate, as well as organically bound chlorine in the pulp and bleach solution. The pulp delignification is characterized by determining the development of the concentration of methanol and methoxyl group containing material in the bleach liquor and that of the functional groups in the residual lignin.
A complete chlorine mass balance was obtained throughout the bleaching reaction. Based on the development of the chlorine containing species, a series of reactions are formulated which give a complete description of the transformation of atomic chlorine during ClO$ sb2$ bleaching. It is found that all organic chlorine, defined as the sum of AOX in the spent bleach liquor and the organically bound chlorine in the chlorinated pulp, is formed within the first 10 minutes of reaction. Subsequently, the increase in AOX in solution is matched by an equivalent decrease of organically bound chlorine in the pulp. The organic chlorine during ClO$ sb2$ bleaching is mainly formed from the reaction between lignin and hypochlorous acid. It is also shown that chlorate is mainly formed by the reaction of two intermediates generated during chlorine dioxide bleaching, chlorite and hypochlorous acid. A theory is presented which explains the effect of operating variables on chlorite formation. The methoxyl group loss from softwood kraft pulp during chlorine dioxide treatment can be accounted for by the methanol produced and the methoxyl content of dissolved organic material in the bleach filtrate. It was found that ClO$ sb2$ rather than the in-situ generated hypochlorous acid is mainly responsible for the methanol formation. The experimental evidence suggests that demethylation and delignification are closely related during ClO$ sb2$ treatment of softwood kraft pulp. Based on the present experimental evidence the ClO$ sb2$ delignification mechanism presented earlier by Gierer and others is modified.
Finally, two techniques are evaluated to decrease the AOX formation in a bleach plant based on respectively the removal of hypochlorous acid by reaction with chlorite, and on decreasing the dissolved lignin concentration. The former can be achieved either by mixing chlorite with pulp prior to the addition of chlorine dioxide, or by converting part of chlorine dioxide to chlorite with hydrogen peroxide. The latter is accomplished by introducing a washing step between the D and C stages of a DC bleach sequence.

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46

Yin, Guohong. "Fundamental aspects of reactions during chlorine dioxide generation and use." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0018/NQ54602.pdf.

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47

Bolinger, Joshua C. "Time-resolved absorption studies of chlorine dioxide photochemistry in solution /." Thesis, Connect to this title online; UW restricted, 2006. http://hdl.handle.net/1773/8551.

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48

Hsu, Chung-Jung. "The removal of phenols from oily wastewater by chlorine dioxide." Thesis, Virginia Tech, 1988. http://hdl.handle.net/10919/45159.

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Treatability studies were performed on oily wastewaters produced by petroleum and canning industries.

Chlorine dioxide was used for the removal of phenolic compounds from these oily wastewaters. Most of phenolic compounds can be destroyed by chlorine dioxide within 15 minutes if CI02-to-phenol ratios of higher than 5.0 are provided. Factors such as pH, temperature, and COD have little effect on phenol removal.

The effectiveness of chlorine dioxide treatment depends critically on the performance of the chlorine dioxide generator. High yields of chlorine dioxide generation can be achieved by maintaining the pH between 2.5 and 3.5, and by controlling the concentration of feed chemicals. For small treatment plants, chlorine dioxide treatment may be an economical process because no expensive equipment is required.
Master of Science

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49

Froass, Peter Michael. "Structural changes in lignin during kraft pulping and chlorine dioxide bleaching." Diss., Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/7031.

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50

Maluleke, Moabi Rachel. "Biofilm monitoring and control using electrochemically activated water and chlorine dioxide." Diss., Pretoria : [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-02162007-122247.

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Dissertations / Theses on the topic 'Dioxyde de chlore'

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