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Partager le résultat de cette recherche Interroger des sources externesEfficacite photocatalytique des oxydes de fer (hematite) et des acides carboxyliques sur la degradation de derives phenoliques chlores en solution aqueuse / Wassila Remache
Titre : Efficacite photocatalytique des oxydes de fer (hematite) et des acides carboxyliques sur la degradation de derives phenoliques chlores en solution aqueuse Type de document : texte imprimé Auteurs : Wassila Remache, Auteur ; Tahar Sehili, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2018 Importance : 168 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
ChimieTags : 2,4-dichlorophénol Photo-Fenton hétérogène Oxyde de fer naturel Fe(III) – carboxylate Acide oxalique Irradiation solaire Solution aqueuse Heterogeneous photo-Fenton Natural iron oxide Oxalic acid Solar radiation ثنائي الكلوروفینول أكسید الحدید الطبیعي الحدید ) -(IIIأكسالات حمض الأكسالیك الإشعاع
الشمسىIndex. décimale : 540 Chimie et sciences connexes Résumé : The degradation of 2,4-DCP photoinduced by natural iron oxide was studied in aqueous suspension up on irradiation at 365 nm and by solar light. The effects of various factors, such as photolysis, adsorption, effect of pH, temperature, wavelength and the degradation pathways were investigated.
The UV light has no considerable influence on the catalytic activity of the NIO, it is very important to note that there is a strong overlap between the absorption spectrum of NIO and the solar emission spectrum of the sun leading the capacity of this oxide to photoinduce the degradation of 2,4-DCP under solar light. 2,4-DCP was nearly completely removed in about 6 h.
The second part of the work of this thesis has demonstrated the significant impact that could have sunlight on the activation of iron-carboxylate complexes in the degradation of 2,4-DCP.
The complex iron-oxalate was found the most photocative for the degradation of 2,4-DCP in both systems (UV and solar irradiation). Photochemical behavior of iron released into solution, mostly influenced by pH, will monitor the effectiveness of the reaction disappearance of the pollutant.
Our results showed that photocatalysis in the iron-oxalate system is an effective technique for the degradation of 2,4-DCP where seven major by-products were identified and that this degradation mainly through hydroxyle radicals •OH. Mineralization of 2,4-DCP was achieved in 11h in our experimental conditions.
Furthermore, in the heterogeneous iron oxide /H2O2 system the method is effective only at acidic conditions and the disappearance of 2,4-DCP is strongly dependent on the concentration of H2O2 , substrate and catalyst dose. The photodegradation of 2,4-DCP can be directly attributed to the attack of •OH radicals. 2,4-DCP is totally degraded that after formation of various by-products can be completely mineralized to H2O, Cl- et CO2.
Our work shows that the activation of natural iron oxide by carboxylic acids and hydrogen peroxide could have a considerable impact on the fate of organic pollutants in aquatic environment.
Diplôme : Doctorat en sciences En ligne : ../theses/chimie/REM7256.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10854 Efficacite photocatalytique des oxydes de fer (hematite) et des acides carboxyliques sur la degradation de derives phenoliques chlores en solution aqueuse [texte imprimé] / Wassila Remache, Auteur ; Tahar Sehili, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2018 . - 168 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
ChimieTags : 2,4-dichlorophénol Photo-Fenton hétérogène Oxyde de fer naturel Fe(III) – carboxylate Acide oxalique Irradiation solaire Solution aqueuse Heterogeneous photo-Fenton Natural iron oxide Oxalic acid Solar radiation ثنائي الكلوروفینول أكسید الحدید الطبیعي الحدید ) -(IIIأكسالات حمض الأكسالیك الإشعاع
الشمسىIndex. décimale : 540 Chimie et sciences connexes Résumé : The degradation of 2,4-DCP photoinduced by natural iron oxide was studied in aqueous suspension up on irradiation at 365 nm and by solar light. The effects of various factors, such as photolysis, adsorption, effect of pH, temperature, wavelength and the degradation pathways were investigated.
The UV light has no considerable influence on the catalytic activity of the NIO, it is very important to note that there is a strong overlap between the absorption spectrum of NIO and the solar emission spectrum of the sun leading the capacity of this oxide to photoinduce the degradation of 2,4-DCP under solar light. 2,4-DCP was nearly completely removed in about 6 h.
The second part of the work of this thesis has demonstrated the significant impact that could have sunlight on the activation of iron-carboxylate complexes in the degradation of 2,4-DCP.
The complex iron-oxalate was found the most photocative for the degradation of 2,4-DCP in both systems (UV and solar irradiation). Photochemical behavior of iron released into solution, mostly influenced by pH, will monitor the effectiveness of the reaction disappearance of the pollutant.
Our results showed that photocatalysis in the iron-oxalate system is an effective technique for the degradation of 2,4-DCP where seven major by-products were identified and that this degradation mainly through hydroxyle radicals •OH. Mineralization of 2,4-DCP was achieved in 11h in our experimental conditions.
Furthermore, in the heterogeneous iron oxide /H2O2 system the method is effective only at acidic conditions and the disappearance of 2,4-DCP is strongly dependent on the concentration of H2O2 , substrate and catalyst dose. The photodegradation of 2,4-DCP can be directly attributed to the attack of •OH radicals. 2,4-DCP is totally degraded that after formation of various by-products can be completely mineralized to H2O, Cl- et CO2.
Our work shows that the activation of natural iron oxide by carboxylic acids and hydrogen peroxide could have a considerable impact on the fate of organic pollutants in aquatic environment.
Diplôme : Doctorat en sciences En ligne : ../theses/chimie/REM7256.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10854 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité REM/7256 REM/7256 Thèse Bibliothèque principale Thèses Disponible
Titre : Degradation photochimique des colorants cationiques sur des supports inorganiques chromophores en solution aqueuse Type de document : texte imprimé Auteurs : Karima Benhamouda, Auteur ; Tahar Sehili, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2017 Importance : 184 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
ChimieTags : Acide oxalique oxyde de fer naturel minéralisation colorants Oxalic acid photo-like- Fenton natural oxide iron mineralization dyes حمض الأكساليك فانتون الضوئي أكسيدالحدیدالطبيعي تمعدن ملون Index. décimale : 540 Chimie et sciences connexes Résumé : The main objective of this study is to test the effectiveness of a natural miniral through
the study of the elimination of two polluting models "methylene blue and rhodamine B" in
aqueous solution.
In a homogeneous phase, various methods have been established to degrade the both
dyes; direct photolysis, photo-oxidation with hydrogen peroxide and persulfate as well as by
the Fenton reagent and photo-Fenton. The results showed that the photo-Fenton process at
254 nm is the most efficient.
The analyses by XRD, IR, Raman and X-ray fluorescence of the natural mineral,
which comes from Souk-Ehres North-East of Algeria, confirmed that this mineral consists of
89 % of hematite, this high content of iron lead us to use this support as a catalyst (source of
iron ions) to create the photo-Fenton-like process in the presence of carboxylic acids.
Among the carboxylic acids studied, oxalic acid is the most effective for the
dissolution of natural iron oxide, therefore for the photodegradation of the MB and RhB.
Indeed, under irradiation, oxalic acid forms a complex with iron oxide and leads to the release
of Fe(III) ions. In solution and by the photoreduction reaction, the Fe(III) ions are transformed
into Fe(II) and leads to the formation of hydrogen peroxide launching a photo-Fenton
reaction, leading to the formation of hydroxyl radicals.
The study of the influence of several physico-chemicals parameters (effect of acid
concentration, temperature, O2, pH, nature of radiation ...) on the efficiency of NIO/OA/UV
process yielded to the determination of optimal conditions for the dyes removal. The
abatement rates of COD for MB and RhB by this process were very reasonable, confirming
the effectiveness of the NIO in the treatments of wastewaters.
The use of natural iron in the presence of oxalic acid under solar irradiation reduces
energy costs, and required time for a total elimination of dyes.Diplôme : Doctorat En ligne : ../theses/chimie/BEN7114.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10487 Degradation photochimique des colorants cationiques sur des supports inorganiques chromophores en solution aqueuse [texte imprimé] / Karima Benhamouda, Auteur ; Tahar Sehili, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2017 . - 184 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
ChimieTags : Acide oxalique oxyde de fer naturel minéralisation colorants Oxalic acid photo-like- Fenton natural oxide iron mineralization dyes حمض الأكساليك فانتون الضوئي أكسيدالحدیدالطبيعي تمعدن ملون Index. décimale : 540 Chimie et sciences connexes Résumé : The main objective of this study is to test the effectiveness of a natural miniral through
the study of the elimination of two polluting models "methylene blue and rhodamine B" in
aqueous solution.
In a homogeneous phase, various methods have been established to degrade the both
dyes; direct photolysis, photo-oxidation with hydrogen peroxide and persulfate as well as by
the Fenton reagent and photo-Fenton. The results showed that the photo-Fenton process at
254 nm is the most efficient.
The analyses by XRD, IR, Raman and X-ray fluorescence of the natural mineral,
which comes from Souk-Ehres North-East of Algeria, confirmed that this mineral consists of
89 % of hematite, this high content of iron lead us to use this support as a catalyst (source of
iron ions) to create the photo-Fenton-like process in the presence of carboxylic acids.
Among the carboxylic acids studied, oxalic acid is the most effective for the
dissolution of natural iron oxide, therefore for the photodegradation of the MB and RhB.
Indeed, under irradiation, oxalic acid forms a complex with iron oxide and leads to the release
of Fe(III) ions. In solution and by the photoreduction reaction, the Fe(III) ions are transformed
into Fe(II) and leads to the formation of hydrogen peroxide launching a photo-Fenton
reaction, leading to the formation of hydroxyl radicals.
The study of the influence of several physico-chemicals parameters (effect of acid
concentration, temperature, O2, pH, nature of radiation ...) on the efficiency of NIO/OA/UV
process yielded to the determination of optimal conditions for the dyes removal. The
abatement rates of COD for MB and RhB by this process were very reasonable, confirming
the effectiveness of the NIO in the treatments of wastewaters.
The use of natural iron in the presence of oxalic acid under solar irradiation reduces
energy costs, and required time for a total elimination of dyes.Diplôme : Doctorat En ligne : ../theses/chimie/BEN7114.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10487 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité BEN/7114 BEN/7114 Thèse Bibliothèque principale Thèses Disponible
