Résultat de la recherche
2 recherche sur le tag
'Procédés d’oxydation Avancés' 
Affiner la recherche Générer le flux rss de la recherche
Partager le résultat de cette recherche Interroger des sources externesContribution 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. / Ibtissem Bousnoubra
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 de l’élimination de deux colorants (Cristal violet et Jaune d’alizarine) par des procédés photochimiques en milieu homogène (lumière artificielle et solaire) et en milieu hétérogène (TiO2/UV et ZnO/UV) : Cas de la transformation photocatalytique du Jaune d’alizarine sur un support transformé : ZnO-Bi2O3/UV Type de document : texte imprimé Auteurs : Sihem Aliouche, Auteur ; Kamel Ezzine Djebbar, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2017 Importance : 190 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
ChimieTags : Dye Photodegradation advanced oxidation processes Photocatalysis semiconductor ملون التفكك الضوئي طرق الأكسدة المتقدمة التحفيز الضوئي المحفزات Colorant Photodégradation procédés d’oxydation avancés Photocatalyse semiconducteur Index. décimale : 540 Chimie et sciences connexes Résumé : This study is focused in the application of different advanced oxidation processes in a
homogeneous and heterogeneous phase for the treatment of two dyes: the AY and the CV.
The direct photolysis of dyes by the artificial light (254nm and 365nm) and solar light is slow
and can be accelerated by increasing of intensity of photon flux incident, or by adding a
photosensitizer such as acetone at high concentration.
In the case of the two dyes studied, it has been shown that the rate of decolorization by the
AOPs in a homogeneous medium such as H2O2/UV, S2O82-/UV and H2O2/S2O82-/UV, has been
substantially improved compared to that obtained by UV photolysis and that the rate depends on
the experimental parameters such as: concentration of substrate, concentration of catalyst and pH
of medium. This improvement could be related to the production of HO• and SO4•- radicals.
Regarding the system UV/S2O82-/H2O2, we have observed that efficiency decreased slightly
due to a competition effect. On the other hand, the persulfate can generate sulfates radicals ions
by heat activation in absence of light. The degradation of the two dyes has been more effective in
Photo-Fenton and Photo-like-Fenton system than in the Fenton and Fenton-like systems
respectively where the performances of these systems could be optimised by variation of the
experimental parameters such as the pH, the [H2O2]/ [Fe2+] and the [H2O2]/ [Fe3+] ratio. In the
(Fe2+/ S2O82-) and the (UV/Fe2+/S2O82-) system, the persulfate acts on the JA similarly to H2O2
compared to the Fenton and Photo-Fenton processes.
In heterogeneous photocatalysis, the degradation of the JA and the CV has been studied using
different semiconductors (TiO2, ZnO, ZnOpure-Bi2O3). The photocatalysis study of the two dyes
by the TiO2 process (Degussa P25)/UV and ZnO/UV has been presented after overseeing a low
adsorption until saturation (30 minutes). Photocatalysis is influenced by various factors where
this process is improved by the addition of H2O2 but has been inhibited by certain inorganic
anions and alcohols. TiO2-P25 is more efficient than Tiona photocatalysts. In addition, the
Langmuir-Hinshelwood model has adequately described this process. The follow up by the
Chemical Oxygen Demand (DCO), confirms that the photocatalysis process leads to the decrease
of the organic matter content until mineralization of pollutants. Tests in natural radiation showed
a faster degradation of bith pollutant. The ZnO pure-Bi2O3/UV process is more efficient than the
two ZnO commercial/UV and ZnO pur/UV processes in terms of degradation.Diplôme : Doctorat en sciences En ligne : ../theses/chimie/ALI7106.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10495 Etude de l’élimination de deux colorants (Cristal violet et Jaune d’alizarine) par des procédés photochimiques en milieu homogène (lumière artificielle et solaire) et en milieu hétérogène (TiO2/UV et ZnO/UV) : Cas de la transformation photocatalytique du Jaune d’alizarine sur un support transformé : ZnO-Bi2O3/UV [texte imprimé] / Sihem Aliouche, Auteur ; Kamel Ezzine Djebbar, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2017 . - 190 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
ChimieTags : Dye Photodegradation advanced oxidation processes Photocatalysis semiconductor ملون التفكك الضوئي طرق الأكسدة المتقدمة التحفيز الضوئي المحفزات Colorant Photodégradation procédés d’oxydation avancés Photocatalyse semiconducteur Index. décimale : 540 Chimie et sciences connexes Résumé : This study is focused in the application of different advanced oxidation processes in a
homogeneous and heterogeneous phase for the treatment of two dyes: the AY and the CV.
The direct photolysis of dyes by the artificial light (254nm and 365nm) and solar light is slow
and can be accelerated by increasing of intensity of photon flux incident, or by adding a
photosensitizer such as acetone at high concentration.
In the case of the two dyes studied, it has been shown that the rate of decolorization by the
AOPs in a homogeneous medium such as H2O2/UV, S2O82-/UV and H2O2/S2O82-/UV, has been
substantially improved compared to that obtained by UV photolysis and that the rate depends on
the experimental parameters such as: concentration of substrate, concentration of catalyst and pH
of medium. This improvement could be related to the production of HO• and SO4•- radicals.
Regarding the system UV/S2O82-/H2O2, we have observed that efficiency decreased slightly
due to a competition effect. On the other hand, the persulfate can generate sulfates radicals ions
by heat activation in absence of light. The degradation of the two dyes has been more effective in
Photo-Fenton and Photo-like-Fenton system than in the Fenton and Fenton-like systems
respectively where the performances of these systems could be optimised by variation of the
experimental parameters such as the pH, the [H2O2]/ [Fe2+] and the [H2O2]/ [Fe3+] ratio. In the
(Fe2+/ S2O82-) and the (UV/Fe2+/S2O82-) system, the persulfate acts on the JA similarly to H2O2
compared to the Fenton and Photo-Fenton processes.
In heterogeneous photocatalysis, the degradation of the JA and the CV has been studied using
different semiconductors (TiO2, ZnO, ZnOpure-Bi2O3). The photocatalysis study of the two dyes
by the TiO2 process (Degussa P25)/UV and ZnO/UV has been presented after overseeing a low
adsorption until saturation (30 minutes). Photocatalysis is influenced by various factors where
this process is improved by the addition of H2O2 but has been inhibited by certain inorganic
anions and alcohols. TiO2-P25 is more efficient than Tiona photocatalysts. In addition, the
Langmuir-Hinshelwood model has adequately described this process. The follow up by the
Chemical Oxygen Demand (DCO), confirms that the photocatalysis process leads to the decrease
of the organic matter content until mineralization of pollutants. Tests in natural radiation showed
a faster degradation of bith pollutant. The ZnO pure-Bi2O3/UV process is more efficient than the
two ZnO commercial/UV and ZnO pur/UV processes in terms of degradation.Diplôme : Doctorat en sciences En ligne : ../theses/chimie/ALI7106.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10495 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité ALI/7106 ALI/7106 Thèse Bibliothèque principale Thèses Disponible
