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Partager le résultat de cette recherche Interroger des sources externesPhotodegradation d’un liquide ionique a base de cation pyridinium en solution aqueuse homogene et heterogene. / Oualida Nour El Houda Kaabeche
Titre : Photodegradation d’un liquide ionique a base de cation pyridinium en solution aqueuse homogene et heterogene. Type de document : texte imprimé Auteurs : Oualida Nour El Houda Kaabeche, Auteur ; Razika Zouaghi, Auteur Mention d'édition : 24/10/2019 Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2019 Importance : 196 f. Format : 30 cm. Note générale : Doctorat 3éme CYCLE LMD.
1 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
ChimieTags : Chimie: Chimie Analytique et Environnement Liquide ionique Photodégradation Procédés d’Oxydation Avancée Radicaux
hydroxyle Photocatalyse Ionic liquid Photodegradation Advanced oxidation processes Hydroxyl radicals Photocatalysis السائل الأيوني التحلل الضوئي عمليات الأكسدة المتقدمة جذور الهيدروكسل التحفيز الضوئيIndex. décimale : 540 Chimie et sciences connexes Résumé : This study focused on the application of photochemical processes (direct photolysis and advanced oxidation processes) in the degradation of an ionic liquid; 1-hexylpyridinium bromide (HPyBr) in aqueous solution. These experiments were conducted in homogeneous phase and in heterogeneous phase. In homogeneous medium, the degradation of HPyBr was studied by different photochemical processes (UV254 nm, UV365 nm, solar irradiation and H2O2/UV254 nm) and by Fenton reagent (Fe2+/H2O2) and photo-Fenton (Fe2+/H2O2 /UV365 nm).
Various physico-chemical parameters have been tested in order to optimize the efficiency of these processes. The comparison of the performances of the various processes studied shows that H2O2/UV254 nm and Fe2+/H2O2/UV365 nm processes are the most efficient. In heterogeneous medium, two metal oxides such as ZnO and TiO2 p25 Degussa were used to compare their photoactivity on the degradation and mineralization of HPyBr. The results obtained show that the percentage of HPyBr adsorption is negligible in the presence of both catalysts. The photocatalytic degradation tests of HPyBr showed that ZnO/UV system was more efficient than the TiO2/UV system, and the disappearance kinetic of HPyBr is correctly described by the Langmuir-Hinshelwood model. The influence of the experimental parameters on the rate of degradation (substrate concentration, catalyst concentrations, pH, the addition of hydrogen peroxide, humic substances, inorganic ions, etc.) was studied. The significant inhibition of the photocatalytic reaction by the addition of chemical scavengers such as isopropanol and triethanolamine confirms that the major pathway for the degradation of HPyBr is due to the hydroxyl •OH radicals formed by irradiation of the photocatalyst surface. The oxidation (COD) and the mineralization (TOC) decrease according to the treatment but more slowly than the degradation, this confirms that the treatment of HPyBr by the photocatalytic process leads to the decrease of the organic matter content, however it requires a relatively slow processing time. In order to verify the feasibility of the photocatalytic process in the environment, both systems were studied under solar irradiation. The results show that the efficiency at this scale is greater than artificial radiation.
Diplôme : Doctorat En ligne : ../theses/chimie/KAA7572.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11410 Photodegradation d’un liquide ionique a base de cation pyridinium en solution aqueuse homogene et heterogene. [texte imprimé] / Oualida Nour El Houda Kaabeche, Auteur ; Razika Zouaghi, Auteur . - 24/10/2019 . - جامعة الإخوة منتوري قسنطينة, 2019 . - 196 f. ; 30 cm.
Doctorat 3éme CYCLE LMD.
1 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
ChimieTags : Chimie: Chimie Analytique et Environnement Liquide ionique Photodégradation Procédés d’Oxydation Avancée Radicaux
hydroxyle Photocatalyse Ionic liquid Photodegradation Advanced oxidation processes Hydroxyl radicals Photocatalysis السائل الأيوني التحلل الضوئي عمليات الأكسدة المتقدمة جذور الهيدروكسل التحفيز الضوئيIndex. décimale : 540 Chimie et sciences connexes Résumé : This study focused on the application of photochemical processes (direct photolysis and advanced oxidation processes) in the degradation of an ionic liquid; 1-hexylpyridinium bromide (HPyBr) in aqueous solution. These experiments were conducted in homogeneous phase and in heterogeneous phase. In homogeneous medium, the degradation of HPyBr was studied by different photochemical processes (UV254 nm, UV365 nm, solar irradiation and H2O2/UV254 nm) and by Fenton reagent (Fe2+/H2O2) and photo-Fenton (Fe2+/H2O2 /UV365 nm).
Various physico-chemical parameters have been tested in order to optimize the efficiency of these processes. The comparison of the performances of the various processes studied shows that H2O2/UV254 nm and Fe2+/H2O2/UV365 nm processes are the most efficient. In heterogeneous medium, two metal oxides such as ZnO and TiO2 p25 Degussa were used to compare their photoactivity on the degradation and mineralization of HPyBr. The results obtained show that the percentage of HPyBr adsorption is negligible in the presence of both catalysts. The photocatalytic degradation tests of HPyBr showed that ZnO/UV system was more efficient than the TiO2/UV system, and the disappearance kinetic of HPyBr is correctly described by the Langmuir-Hinshelwood model. The influence of the experimental parameters on the rate of degradation (substrate concentration, catalyst concentrations, pH, the addition of hydrogen peroxide, humic substances, inorganic ions, etc.) was studied. The significant inhibition of the photocatalytic reaction by the addition of chemical scavengers such as isopropanol and triethanolamine confirms that the major pathway for the degradation of HPyBr is due to the hydroxyl •OH radicals formed by irradiation of the photocatalyst surface. The oxidation (COD) and the mineralization (TOC) decrease according to the treatment but more slowly than the degradation, this confirms that the treatment of HPyBr by the photocatalytic process leads to the decrease of the organic matter content, however it requires a relatively slow processing time. In order to verify the feasibility of the photocatalytic process in the environment, both systems were studied under solar irradiation. The results show that the efficiency at this scale is greater than artificial radiation.
Diplôme : Doctorat En ligne : ../theses/chimie/KAA7572.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11410 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité KAA/7572 KAA/7572 Thèse Bibliothèque principale Thèses Disponible
Titre : Photodégradation du chlorure de 1-hexyl-3- methylimidazolium en milieu aqueux homogène et hétérogène. Type de document : texte imprimé Auteurs : Ameur Boutiti, Auteur ; Razika Zouaghi, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2018 Importance : 123 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
ChimieTags : Photodégradation Liquide ionique Procédé d’Oxydation Avancée H2O2/UV S2O82–/UV TiO2/UV Photodegradation Ionic liquid Advanced Oxidation Processes الهدم الضوئي السائل الأيوني طرق الأكسدة Index. décimale : 540 Chimie et sciences connexes Résumé : 1-hexyl-3-methylimidazolium chloride (HMImCl) removal from aqueous solution has been achieved by different advanced oxidation processes (AOPs).
HMImCl direct photolysis at 254 nm showed that oxygen mainly intervenes to give O2–·, it can then react with water to form hydrogen peroxide, capable to photolyze and lead to the formation of radicals HO•. On the other hand, singlet oxygen does not participate in the oxidation reaction.
HMImCl degradation rate is appreciably increased by combining the strong oxidant H2O2 with UV light. The H2O2/UV process efficiency is enhanced by increasing H2O2 concentration up to a limit value imposed by self-quenching reactions. High alkalinity favors the disappearance while current inorganic anions chlorides, in acidic medium, inhibit it. Very similar results are obtained with S2O82-/UV process with, in particular, a rate that increases up to a limiting value of the oxidant concentration.
The reaction rate constants of the hydroxyl radicals determined for the two ionic liquids studied, transcribe the high reactivity and the speed of reaction of hydroxyl radicals on ionic liquid. The reaction rate constant of hydroxyl radicals on HMImCl is the same whatever the concentration of HMImCl Heterogeneous photocatalysis on TiO2 proved to be efficient to degrade HMImCl. The process is further improved by H2O2 or S2O82- addition up to an optimum but inhibited by anion chloride in acidic medium. The process is adequately described by the LangmuirHinshelwood kinetic model.
Selective heterogeneous photocatalysis of HMImCl in presence of benzoic acid has demonstrated that benzoic acid affect HMImCl’s degradation. A good selectivity was obtained in acidic medium, where only benzoic acid has been degraded.
Diplôme : Doctorat en sciences En ligne : ../theses/chimie/BOU7188.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10750 Photodégradation du chlorure de 1-hexyl-3- methylimidazolium en milieu aqueux homogène et hétérogène. [texte imprimé] / Ameur Boutiti, Auteur ; Razika Zouaghi, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2018 . - 123 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
ChimieTags : Photodégradation Liquide ionique Procédé d’Oxydation Avancée H2O2/UV S2O82–/UV TiO2/UV Photodegradation Ionic liquid Advanced Oxidation Processes الهدم الضوئي السائل الأيوني طرق الأكسدة Index. décimale : 540 Chimie et sciences connexes Résumé : 1-hexyl-3-methylimidazolium chloride (HMImCl) removal from aqueous solution has been achieved by different advanced oxidation processes (AOPs).
HMImCl direct photolysis at 254 nm showed that oxygen mainly intervenes to give O2–·, it can then react with water to form hydrogen peroxide, capable to photolyze and lead to the formation of radicals HO•. On the other hand, singlet oxygen does not participate in the oxidation reaction.
HMImCl degradation rate is appreciably increased by combining the strong oxidant H2O2 with UV light. The H2O2/UV process efficiency is enhanced by increasing H2O2 concentration up to a limit value imposed by self-quenching reactions. High alkalinity favors the disappearance while current inorganic anions chlorides, in acidic medium, inhibit it. Very similar results are obtained with S2O82-/UV process with, in particular, a rate that increases up to a limiting value of the oxidant concentration.
The reaction rate constants of the hydroxyl radicals determined for the two ionic liquids studied, transcribe the high reactivity and the speed of reaction of hydroxyl radicals on ionic liquid. The reaction rate constant of hydroxyl radicals on HMImCl is the same whatever the concentration of HMImCl Heterogeneous photocatalysis on TiO2 proved to be efficient to degrade HMImCl. The process is further improved by H2O2 or S2O82- addition up to an optimum but inhibited by anion chloride in acidic medium. The process is adequately described by the LangmuirHinshelwood kinetic model.
Selective heterogeneous photocatalysis of HMImCl in presence of benzoic acid has demonstrated that benzoic acid affect HMImCl’s degradation. A good selectivity was obtained in acidic medium, where only benzoic acid has been degraded.
Diplôme : Doctorat en sciences En ligne : ../theses/chimie/BOU7188.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10750 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité BOU/7188 BOU/7188 Thèse Bibliothèque principale Thèses Disponible
Titre : Elimination de deux polluants organiques par photo-induction en phase homogène et hétérogène et par adsorption sur des supports inorganiques locaux. Type de document : texte imprimé Auteurs : Badis Khennaoui, Auteur ; Moulay Abderrahmane Malouki, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2018 Importance : 164 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles. Langues : Français (fre) Catégories : Français - Anglais
ChimieTags : Processus avancés d'oxydation Photo-Fenton hétérogène Photodégradation Polluants Photocatalyseur Advanced oxidation processes heterogeneous Photo-Fenton Photodegradation Pollutants Photocatalyst عميات الأكسدة المتقدمة فوتو-فنتون غير متجانسة التحلل الضوئي الملوثات التحفيز الضوئي Index. décimale : 540 Chimie et sciences connexes Résumé : This work aims to study and evaluate the efficiency of a photo- catalytic process photoFenton-type for the removal from aqueous medium of an azo dye (orange methyl) and a pesticide (linuron) belonging to phenylurea family. It was for objective to study (or to investigate) the photocatalytic activity of a local clay rich in iron oxide for the degradation of certain kind of organic compounds, in particular dyes and pesticides.
The first part of this work has been devoted to the acquisition of some local clay and the obtaining of their characteristic properties by a few characterization methods such as: thermal analysis (ATD and ATG), scanning electron microscope, X-ray diffraction, UV-visible spectroscopy and X-ray fluorescence.
The adsorption kinetics of two pollutants showed that the equilibrium is reached practically in 30 minutes. The adsorption rate was rapid at the first 15 minutes of the process and then becomes slow for the rest of stirring time to reach equilibrium after 30 minutes.
The photo-degradation process of heterogeneous photo-Fenton type (clay/pollutant/oxalic acid/UV system) was studied by monitoring the change in the concentration of organic pollutants using the UV-Vis spectroscopic analysis technique as a function of irradiation time.
The degradation was studied by investigating the effect of different operational parameters such as: the initial pH, the concentration of the catalyst and the concentration of organic materials.
The results indicated that the photodegradation rate of two pollutants was clearly increased in the presence of clay compared with the direct photolysis. The introduction of oxalic acid considerably improved the photocatalytic process (about 90% removal). The optimal conditions for a better degradation were obtained for: [clay] = 1 g/L and acidic pH (between 3 and 4) in the presence of [oxalic acid] = 10-2 M.
The exposition of the photocatalytic system to sunlight causes the disappearance the organic pollutant in a significant way. This fact is very promising and highlighting the possibility of using sunlight, a source of renewable and free energy as an alternative to UV radiations for the elimination of organic pollutants from the aquatic environment.
Diplôme : Doctorat en sciences En ligne : ../theses/chimie/KHE7205.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10758 Elimination de deux polluants organiques par photo-induction en phase homogène et hétérogène et par adsorption sur des supports inorganiques locaux. [texte imprimé] / Badis Khennaoui, Auteur ; Moulay Abderrahmane Malouki, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2018 . - 164 f. ; 30 cm.
2 copies imprimées disponibles.
Langues : Français (fre)
Catégories : Français - Anglais
ChimieTags : Processus avancés d'oxydation Photo-Fenton hétérogène Photodégradation Polluants Photocatalyseur Advanced oxidation processes heterogeneous Photo-Fenton Photodegradation Pollutants Photocatalyst عميات الأكسدة المتقدمة فوتو-فنتون غير متجانسة التحلل الضوئي الملوثات التحفيز الضوئي Index. décimale : 540 Chimie et sciences connexes Résumé : This work aims to study and evaluate the efficiency of a photo- catalytic process photoFenton-type for the removal from aqueous medium of an azo dye (orange methyl) and a pesticide (linuron) belonging to phenylurea family. It was for objective to study (or to investigate) the photocatalytic activity of a local clay rich in iron oxide for the degradation of certain kind of organic compounds, in particular dyes and pesticides.
The first part of this work has been devoted to the acquisition of some local clay and the obtaining of their characteristic properties by a few characterization methods such as: thermal analysis (ATD and ATG), scanning electron microscope, X-ray diffraction, UV-visible spectroscopy and X-ray fluorescence.
The adsorption kinetics of two pollutants showed that the equilibrium is reached practically in 30 minutes. The adsorption rate was rapid at the first 15 minutes of the process and then becomes slow for the rest of stirring time to reach equilibrium after 30 minutes.
The photo-degradation process of heterogeneous photo-Fenton type (clay/pollutant/oxalic acid/UV system) was studied by monitoring the change in the concentration of organic pollutants using the UV-Vis spectroscopic analysis technique as a function of irradiation time.
The degradation was studied by investigating the effect of different operational parameters such as: the initial pH, the concentration of the catalyst and the concentration of organic materials.
The results indicated that the photodegradation rate of two pollutants was clearly increased in the presence of clay compared with the direct photolysis. The introduction of oxalic acid considerably improved the photocatalytic process (about 90% removal). The optimal conditions for a better degradation were obtained for: [clay] = 1 g/L and acidic pH (between 3 and 4) in the presence of [oxalic acid] = 10-2 M.
The exposition of the photocatalytic system to sunlight causes the disappearance the organic pollutant in a significant way. This fact is very promising and highlighting the possibility of using sunlight, a source of renewable and free energy as an alternative to UV radiations for the elimination of organic pollutants from the aquatic environment.
Diplôme : Doctorat en sciences En ligne : ../theses/chimie/KHE7205.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10758 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité KHE/7205 KHE/7205 Thèse Bibliothèque principale Thèses Disponible
Titre : Contribution à l’élimination de colorants (Vert de méthyle et Bromocrésol pourpre) par procédés photochimiques en phase homogène (séparés et mélangés), en phase hétérogène en milieu aqueux et par adsorption (Vert de méthyle) sur ZnO. Type de document : texte imprimé Auteurs : Ibtissem Bousnoubra, Auteur ; Kamel Djebbar, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2017 Importance : 209 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
ChimieTags : Photodégradation Procédés d’oxydation Avancés Photocatalyse Vert de méthyle Bromocrésol pourpre Photodegradation Advanced oxidation Processes photocatalysis Méthyle green Bromocresol purple تحلل ضوئي عمليات الاكسدة المتقدمة الفوتوتحفيزية أخضر المثيل بنفسجي البرموكريزول Index. décimale : 540 Chimie et sciences connexes Résumé : The study was aimed to study and to compare efficiences of photochemical processes (direct photolysis and advanced oxidation processes POAs) in the degradation of two dyes: the méthyle green and purple Bromocresol. These experiments have occurred in homogeneous phase where the two dyes were studied separately, in a binary mixture and in heterogeneous phase by using ZnO / UV and TiO2 (PC500) / UV.
In Direct photolysis (365 nm and solar light), the elimination yields is weak, mainly,in rtificial light. However and at 254 nm, the BCP only conducts to good results comparatively to these of MG. In another part, a total decolorization of both substrates is obtained by using a
photosensitizer: acetone (10-1 mol. L-1).
In photooxidation (H2O2/UV et S2O8-2/UV), this process was much efficient due to the participation of radicals •OH and SO4•-, this work was undertaken by taking into account the
sensitivity of both dyes in presence of H2O2 and S2O8-2 in absence of light where we observe an insensitivity of BCP towards H2O2 but a sensitivity of MG for H2O2> 10-5M. In this
research, other processes have led also to a good elimination like Fe2+/ H2O2/ UV (254 nm) and Fe3+/ H2O2/
UV (254 nm). The results obtained with these systems, were much more probants comparatively
with Fenton and Like-Fenton. For the binary system, it was observed in one part that the
decolorization of the dye decreases with the addition of the second dye and in another part that
the process acetone/UV is the best system comparatively to direct photolysis UV and H2O2 / UV.
Besides, no change in the kinetics models is observed in the binary system.
In photocatalysis, the elimination of MG and BCP was total with ZnO/UV and TiO2
(PC500)/UV where this one is related directly to radical •OH. Studies were also conducted in
sunlight and demonstrate the superiority of this latter comparatively to the artificial light (99,
74% in 60 minutes for MG and 100% in 120 minutes for BCP). The Langmuir Hinshelwood model describes correctly this process. It should be mentioned that in absence of light, MG showed a better adsorption capacity than BCP where it reached 92% in 180 minutes. The monitoring function of the DCO elimination showed that it depends to the organic matter and decreases over time.
Diplôme : Doctorat en sciences En ligne : ../theses/chimie/BOU7006.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10382 Contribution à l’élimination de colorants (Vert de méthyle et Bromocrésol pourpre) par procédés photochimiques en phase homogène (séparés et mélangés), en phase hétérogène en milieu aqueux et par adsorption (Vert de méthyle) sur ZnO. [texte imprimé] / Ibtissem Bousnoubra, Auteur ; Kamel Djebbar, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2017 . - 209 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
ChimieTags : Photodégradation Procédés d’oxydation Avancés Photocatalyse Vert de méthyle Bromocrésol pourpre Photodegradation Advanced oxidation Processes photocatalysis Méthyle green Bromocresol purple تحلل ضوئي عمليات الاكسدة المتقدمة الفوتوتحفيزية أخضر المثيل بنفسجي البرموكريزول Index. décimale : 540 Chimie et sciences connexes Résumé : The study was aimed to study and to compare efficiences of photochemical processes (direct photolysis and advanced oxidation processes POAs) in the degradation of two dyes: the méthyle green and purple Bromocresol. These experiments have occurred in homogeneous phase where the two dyes were studied separately, in a binary mixture and in heterogeneous phase by using ZnO / UV and TiO2 (PC500) / UV.
In Direct photolysis (365 nm and solar light), the elimination yields is weak, mainly,in rtificial light. However and at 254 nm, the BCP only conducts to good results comparatively to these of MG. In another part, a total decolorization of both substrates is obtained by using a
photosensitizer: acetone (10-1 mol. L-1).
In photooxidation (H2O2/UV et S2O8-2/UV), this process was much efficient due to the participation of radicals •OH and SO4•-, this work was undertaken by taking into account the
sensitivity of both dyes in presence of H2O2 and S2O8-2 in absence of light where we observe an insensitivity of BCP towards H2O2 but a sensitivity of MG for H2O2> 10-5M. In this
research, other processes have led also to a good elimination like Fe2+/ H2O2/ UV (254 nm) and Fe3+/ H2O2/
UV (254 nm). The results obtained with these systems, were much more probants comparatively
with Fenton and Like-Fenton. For the binary system, it was observed in one part that the
decolorization of the dye decreases with the addition of the second dye and in another part that
the process acetone/UV is the best system comparatively to direct photolysis UV and H2O2 / UV.
Besides, no change in the kinetics models is observed in the binary system.
In photocatalysis, the elimination of MG and BCP was total with ZnO/UV and TiO2
(PC500)/UV where this one is related directly to radical •OH. Studies were also conducted in
sunlight and demonstrate the superiority of this latter comparatively to the artificial light (99,
74% in 60 minutes for MG and 100% in 120 minutes for BCP). The Langmuir Hinshelwood model describes correctly this process. It should be mentioned that in absence of light, MG showed a better adsorption capacity than BCP where it reached 92% in 180 minutes. The monitoring function of the DCO elimination showed that it depends to the organic matter and decreases over time.
Diplôme : Doctorat en sciences En ligne : ../theses/chimie/BOU7006.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10382 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité BOU/7006 BOU/7006 Thèse Bibliothèque principale Thèses Disponible
Titre : Etude comparative de la dégradation de colorants de la famille des triphénylméthanes par voies photochimique et sonochimique en solution aqueuse homogène et hétérogène. Type de document : texte imprimé Auteurs : Seyfeddine Bendjabeur, Auteur ; Razika Zouaghi, Directeur de thèse Mention d'édition : 10-mars-19 Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2019 Importance : 251 f. Format : 30 cm. Note générale : Doctorat 3éme CYCLE LMD.
1 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
ChimieTags : Chimie: Chimie Analytique et Environnement Colorant adsorption Photolyse Procédés d’Oxydations Avancée H2O2 UV TiO2 Photocatalyse sonolyse dye photolysis advanced oxidation processes photocatalysis sonolysis صبغ امتزاز تحلل ضوئي عمليات أكسدة متطورة 2H20 الأشعة فوق البنفسجية و تحفيز ضوئي تحلل صوتي Index. décimale : 540 Chimie et sciences connexes Résumé : This study focused on the elimination of three dyes by several advanced sonochemical and photochemical oxidation processes in a homogeneous and heterogeneous medium as well as by direct photolysis at 254 and 365 nm. In most of the cases studied, a pseudo-first order kinetic law applies correctly to a large part of the reactions. The results obtained in this study indicated that photolysis (UV only) was found to have little effect on the degradation of the three dyes. The removal efficiency can be improved by increasing the intensity of the photonic flux or by decreasing the initial concentration of pollutant.
The coupling of H2O2/UV increases considerably the degradation rate of the three dyes, the efficiency is enhanced by raising the dose of H2O2 up to a limit imposed by the self-inhibition reactions. The DT-DFT method allowed recalculating the theoretical UV-Visible spectra of the three dyes which are comparable to that obtained experimentally. Adsorption and heterogeneous Photocatalysis were influenced by various factors (initial substrate concentration, catalyst type and loading, pH of the solution, addition of hydrogen peroxide, and the presence of inorganic salts). The results showed that the degradation yield of the three dyes is very high when using TiO2-P25, where a complete photocatalytic degradation of 10 mg L-1 of GV, BF and AF was obtained in 25, 30 and 50 minutes in the presence of 1 g L-1 of TiO2 Degussa P25 at natural pH. First-order kinetics described the photocatalytic reaction of the three substrates andthe Langmuir-Hinshelwood model correctly described the photocatalysis processes of the substrates tested. The comparison between various types of catalysts (Degussa P25, Millenium PC500, PC105, PC100, and PC50) gave varied results but Degussa P25 was the most efficient photocatalyst from which it was chosen for this study. The optimum catalyst concentration was 1 g L-1 of TiO2 with an initial concentration of 10 mg L-1 of dye. Finally, the sonochemical degradation of GV by sonolysis at 516 kHz shows that this method is effective for the degradation of this dye. However, this process can be affected by several parameters including, applied electrical power, initial substrate concentration, pHof the solution, the addition of H2O2 and S2O82- and the presence of someinorganic ions.Note de contenu : Annexe.
Diplôme : Doctorat En ligne : ../theses/chimie/BEN7567.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11405 Etude comparative de la dégradation de colorants de la famille des triphénylméthanes par voies photochimique et sonochimique en solution aqueuse homogène et hétérogène. [texte imprimé] / Seyfeddine Bendjabeur, Auteur ; Razika Zouaghi, Directeur de thèse . - 10-mars-19 . - جامعة الإخوة منتوري قسنطينة, 2019 . - 251 f. ; 30 cm.
Doctorat 3éme CYCLE LMD.
1 copies imprimées disponibles
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ChimieTags : Chimie: Chimie Analytique et Environnement Colorant adsorption Photolyse Procédés d’Oxydations Avancée H2O2 UV TiO2 Photocatalyse sonolyse dye photolysis advanced oxidation processes photocatalysis sonolysis صبغ امتزاز تحلل ضوئي عمليات أكسدة متطورة 2H20 الأشعة فوق البنفسجية و تحفيز ضوئي تحلل صوتي Index. décimale : 540 Chimie et sciences connexes Résumé : This study focused on the elimination of three dyes by several advanced sonochemical and photochemical oxidation processes in a homogeneous and heterogeneous medium as well as by direct photolysis at 254 and 365 nm. In most of the cases studied, a pseudo-first order kinetic law applies correctly to a large part of the reactions. The results obtained in this study indicated that photolysis (UV only) was found to have little effect on the degradation of the three dyes. The removal efficiency can be improved by increasing the intensity of the photonic flux or by decreasing the initial concentration of pollutant.
The coupling of H2O2/UV increases considerably the degradation rate of the three dyes, the efficiency is enhanced by raising the dose of H2O2 up to a limit imposed by the self-inhibition reactions. The DT-DFT method allowed recalculating the theoretical UV-Visible spectra of the three dyes which are comparable to that obtained experimentally. Adsorption and heterogeneous Photocatalysis were influenced by various factors (initial substrate concentration, catalyst type and loading, pH of the solution, addition of hydrogen peroxide, and the presence of inorganic salts). The results showed that the degradation yield of the three dyes is very high when using TiO2-P25, where a complete photocatalytic degradation of 10 mg L-1 of GV, BF and AF was obtained in 25, 30 and 50 minutes in the presence of 1 g L-1 of TiO2 Degussa P25 at natural pH. First-order kinetics described the photocatalytic reaction of the three substrates andthe Langmuir-Hinshelwood model correctly described the photocatalysis processes of the substrates tested. The comparison between various types of catalysts (Degussa P25, Millenium PC500, PC105, PC100, and PC50) gave varied results but Degussa P25 was the most efficient photocatalyst from which it was chosen for this study. The optimum catalyst concentration was 1 g L-1 of TiO2 with an initial concentration of 10 mg L-1 of dye. Finally, the sonochemical degradation of GV by sonolysis at 516 kHz shows that this method is effective for the degradation of this dye. However, this process can be affected by several parameters including, applied electrical power, initial substrate concentration, pHof the solution, the addition of H2O2 and S2O82- and the presence of someinorganic ions.Note de contenu : Annexe.
Diplôme : Doctorat En ligne : ../theses/chimie/BEN7567.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11405 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité BEN/7567 BEN/7567 Thèse Bibliothèque principale Thèses Disponible
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