Titre :	Degradation d’un polluant organique (herbicide) photocatalysee par des materiaux inorganiques vierges et dopes par la lumiere artificielle et solaire en solution aqueuse
Type de document :	texte imprimé
Auteurs :	Hind Mechakra, Auteur ; Tahar Sehili, Directeur de thèse
Editeur :	جامعة الإخوة منتوري قسنطينة
Année de publication :	2016
Importance :	176 f.
Format :	30 cm.
Note générale :	Doctorat 3éme CYCLE. 2 copies imprimées disponibles
Langues :	Français (fre)
Catégories :	Français - Anglais Chimie
Tags :	Chimie Analytique et Environnement  Herbicide  Linuron  Oxyde de fer naturel  hématite  Procédé d’oxydation avancée  Adsorption  Photo Like Fenton  Nanoparticules Natural Iron Oxide  hematite  Advanced oxidation process  Nanoparticles  مبيدات الأعشاب  اللينورون  أكسيد الحديد الطبيعي  الهيماتيت  عملية الأكسدة المتقدمة  الامتزاز  عملية فنتون  الجزيئات النانونية
Index. décimale :	540 Chimie et sciences connexes
Résumé :	This doctoral work focused on the study of the elimination of an herbicide, the linuron, in aqueous phase, using various degradation processes especially iron oxides. The aim is to apply these methods for the depollution of aqueous effluents related to the fabrication and the use of pesticides. Analytical tools for the mineralization decomposition kinetics and the identification of by-products of degradation have been used. Hydrogen peroxide and carboxylic acids addition significantly improves the degradation and mineralization due to the production of strong oxidizing radicals. Moreover, the implication of radical species has been demonstrated in the studied systems as evidenced by the addition of radical inhibitor (isopropanol). In the first part, the degradation of linuron was carried out in a homogeneous medium. The speed degradation constants were determined for the different processes (UV,H2O2 / UV, H2O2 / Fe2+ / UV). In the second part, the heterogeneous systems using a natural iron oxide were studied. The main photoproducts were identified by UHPLC / MS and their kinetics were drawn. Mineralization has been followed and degradation mechanisms have been proposed. These mechanisms primarily involve (i) the hydroxylation of the aromatic ring with or without simultaneous dechlorination, (ii) the N-demethylation of N-methylurea and (iii) the N-demethoxylation of substituted-N-methoxyurea. Finally, linuron degradation by natural iron oxide (NIO) was compared with the photocatalytic system involving a labsynthesized nanoscale iron oxide (NPs). It appeared that the degradation in NIO H2O2/ UV and NPs/ H2O2/ UV systems is effective in acid while the pH does not play an important role in NIO/ UV and NPs/ UV system.
Diplôme :	Doctorat
En ligne :	../theses/chimie/MEC6982.pdf
Format de la ressource électronique :	pdf
Permalink :	index.php?lvl=notice_display&id=10413

Degradation d’un polluant organique (herbicide) photocatalysee par des materiaux inorganiques vierges et dopes par la lumiere artificielle et solaire en solution aqueuse [texte imprimé] / Hind Mechakra, Auteur ; Tahar Sehili, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2016 . - 176 f. ; 30 cm.
Doctorat 3éme CYCLE.
2 copies imprimées disponibles

Langues : Français (fre)

Catégories :	Français - Anglais Chimie
Tags :	Chimie Analytique et Environnement  Herbicide  Linuron  Oxyde de fer naturel  hématite  Procédé d’oxydation avancée  Adsorption  Photo Like Fenton  Nanoparticules Natural Iron Oxide  hematite  Advanced oxidation process  Nanoparticles  مبيدات الأعشاب  اللينورون  أكسيد الحديد الطبيعي  الهيماتيت  عملية الأكسدة المتقدمة  الامتزاز  عملية فنتون  الجزيئات النانونية
Index. décimale :	540 Chimie et sciences connexes
Résumé :	This doctoral work focused on the study of the elimination of an herbicide, the linuron, in aqueous phase, using various degradation processes especially iron oxides. The aim is to apply these methods for the depollution of aqueous effluents related to the fabrication and the use of pesticides. Analytical tools for the mineralization decomposition kinetics and the identification of by-products of degradation have been used. Hydrogen peroxide and carboxylic acids addition significantly improves the degradation and mineralization due to the production of strong oxidizing radicals. Moreover, the implication of radical species has been demonstrated in the studied systems as evidenced by the addition of radical inhibitor (isopropanol). In the first part, the degradation of linuron was carried out in a homogeneous medium. The speed degradation constants were determined for the different processes (UV,H2O2 / UV, H2O2 / Fe2+ / UV). In the second part, the heterogeneous systems using a natural iron oxide were studied. The main photoproducts were identified by UHPLC / MS and their kinetics were drawn. Mineralization has been followed and degradation mechanisms have been proposed. These mechanisms primarily involve (i) the hydroxylation of the aromatic ring with or without simultaneous dechlorination, (ii) the N-demethylation of N-methylurea and (iii) the N-demethoxylation of substituted-N-methoxyurea. Finally, linuron degradation by natural iron oxide (NIO) was compared with the photocatalytic system involving a labsynthesized nanoscale iron oxide (NPs). It appeared that the degradation in NIO H2O2/ UV and NPs/ H2O2/ UV systems is effective in acid while the pH does not play an important role in NIO/ UV and NPs/ UV system.
Diplôme :	Doctorat
En ligne :	../theses/chimie/MEC6982.pdf
Format de la ressource électronique :	pdf
Permalink :	index.php?lvl=notice_display&id=10413