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Auteur Tahar Sehili |
Documents disponibles écrits par cet auteur (11)
Affiner la recherche Interroger des sources externesDegradation de colorants azoïques par les procédés d’oxydation avancée en solution aqueuse. / Safa Larouk
Titre : Degradation de colorants azoïques par les procédés d’oxydation avancée en solution aqueuse. Type de document : texte imprimé Auteurs : Safa Larouk, Auteur ; Tahar Sehili, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2019 Importance : 182 f. Format : 30 cm. Note générale : Doctorat 3éme CYCLE LMD.
2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
ChimieTags : Chimie: Chimie Analytique et Environnement Photocatalyse Ozonation catalysée Orange G Hématite (NIO) Mésoporeux SBA Solution aqueuse Photocatalysis Catalyzed Ozonation Hematite (NIO) Mesoporous SBA Aqueous solution التحفيز الضوئي الهيماتيت أكسيد التيتانيوم مادة السيلكا المحلول المائي الازون المحفزات الصلبة الملوث Index. décimale : 540 Chimie et sciences connexes Résumé :
Textile industries release large quantities of wastewater containing dyes with a high
toxicity risk. Primary treatment methods are unsatisfactory, advanced oxidation processes (AOPs) are effective. They allow the total mineralization of pollutants in CO2, H2O and corresponding mineral acids. The photochemical process during the degradation of OG has been studied. Photocatalysis in the presence of NIO is more effective than TiO2, 91% and 85% of OG disappeared after 300 minutes respectively. A parametric study was performed by UV-Vis spectrophotometer. The results of photochemistry have shown that the NIO-Oxalic Acid -UV process is effective for the degradation of OG. In the second study, we chose a silica-based material of SBA-16 type associated with NIO to degrade OG by catalytic ozonation. The NIO and SBA-16 associated with ozone greatly improve the degradation of OG. The total degradation of the substrate was obtained in half the time with NIO or SBA-16 alone. The primary analytical study of ozonation was confirmed by LC-MS-TOF and led to hydroxyl by-products mainly on aromatic rings. The formation of tertiary by-products such as: phthalic acid, catechol and hydroquinone have been observed. The results of the parameter interactions were obtained through three factorial designs of experiments using NIO, SBA-16 alone and 1: 1 weight /weight of NIO/SBA-16.
Note de contenu :
Annexes.Diplôme : Doctorat En ligne : ../theses/chimie/LAR7419.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11072 Degradation de colorants azoïques par les procédés d’oxydation avancée en solution aqueuse. [texte imprimé] / Safa Larouk, Auteur ; Tahar Sehili, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2019 . - 182 f. ; 30 cm.
Doctorat 3éme CYCLE LMD.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
ChimieTags : Chimie: Chimie Analytique et Environnement Photocatalyse Ozonation catalysée Orange G Hématite (NIO) Mésoporeux SBA Solution aqueuse Photocatalysis Catalyzed Ozonation Hematite (NIO) Mesoporous SBA Aqueous solution التحفيز الضوئي الهيماتيت أكسيد التيتانيوم مادة السيلكا المحلول المائي الازون المحفزات الصلبة الملوث Index. décimale : 540 Chimie et sciences connexes Résumé :
Textile industries release large quantities of wastewater containing dyes with a high
toxicity risk. Primary treatment methods are unsatisfactory, advanced oxidation processes (AOPs) are effective. They allow the total mineralization of pollutants in CO2, H2O and corresponding mineral acids. The photochemical process during the degradation of OG has been studied. Photocatalysis in the presence of NIO is more effective than TiO2, 91% and 85% of OG disappeared after 300 minutes respectively. A parametric study was performed by UV-Vis spectrophotometer. The results of photochemistry have shown that the NIO-Oxalic Acid -UV process is effective for the degradation of OG. In the second study, we chose a silica-based material of SBA-16 type associated with NIO to degrade OG by catalytic ozonation. The NIO and SBA-16 associated with ozone greatly improve the degradation of OG. The total degradation of the substrate was obtained in half the time with NIO or SBA-16 alone. The primary analytical study of ozonation was confirmed by LC-MS-TOF and led to hydroxyl by-products mainly on aromatic rings. The formation of tertiary by-products such as: phthalic acid, catechol and hydroquinone have been observed. The results of the parameter interactions were obtained through three factorial designs of experiments using NIO, SBA-16 alone and 1: 1 weight /weight of NIO/SBA-16.
Note de contenu :
Annexes.Diplôme : Doctorat En ligne : ../theses/chimie/LAR7419.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11072 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité LAR/7419 LAR/7419 Thèse Bibliothèque principale Thèses Disponible
Titre : Degradation photocatalytique du 1-naphtol en presence d’oxyde de fer naturel chromophore et de tio2 en solution aqueuse Type de document : texte imprimé Auteurs : Lamia Mammeri, Auteur ; Tahar Sehili, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2016 Importance : 220 f. Note générale : 2 copies imprimees disponibles Langues : Français (fre) Catégories : Français - Anglais
ChimieTags : Minerai naturel, photodégradation, radicaux hydroxyle, peroxyde d’hydrogène, acide
oxalique, photo-Fenton hétérogène.
Natural mineral, photodegradation, hydroxyl radicals, hydrogen peroxide, oxalic
acid, heterogeneous photo-Fenton.
خام طبيعي، التحلل الضوئي، جذور الهيدروكسيل، الماء الأكسجيني، حمض الأكزاليك، مفاعل فوتو فنتون في
وسط غير متجانسIndex. décimale : 540 Chimie et sciences connexes Résumé : This work was carried out in the field of water treatment using advanced oxidation processes
(AOPs), particularly the photocatalysis process in heterogeneous environments. The 1-Naphthol
(1-NP) was chosen as a model contaminant molecule to evaluate the photocatalytic performance
of a naturel mineral (NM).
In a homogeneous medium, the degradation of 1-NP has been studied by different
photochemical processes (UV254 nm, UV365 nm, solar irradiation and H2O2/UV254 nm) and by the
Fenton's reagent (Fe2+/H2O2). The performance comparison of the different processes studied
shows that the process of Fe2+/H2O2 is the most effective.
The 1-NP was degraded by heterogeneous photocatalysis using TiO2 and Fe2O3 as supporting
chromophores. This study showed the relative efficiency of the NM in inducing the 1-NP
photodegradation. The photodegradation kinetics are more important when using TiO2. In the
presence of NM, it appears that the •OH radicals are not involved in the degradation mechanism
of 1-NP.
Moreover, the study of the system 1-NP - NM - H2O2 showed that 1-NP disappears more
rapidly due to the intervention of the hydroxyl radicals generated by the Fenton and photoFenton reactions. The degradation rate depends on the concentration of hydrogen peroxide and
the pH of the medium.
It has also been observed that the addition of the oxalic acid in a NM solution significantly
enhances the rate of the degradation of the substrate similar to that of hydrogen peroxide. This
degradation is carried out by the oxidizing action of the hydroxyl radicals. However, the
alkalinization of the medium completely restrains the reaction.
Different natural irradiation tests have shown a more rapid degradation of the pollutant. This
environmentally friendly method appears to be very effective in the treatment of wastewater.Diplôme : Doctorat en sciences En ligne : ../theses/chimie/MAM6855.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10163 Degradation photocatalytique du 1-naphtol en presence d’oxyde de fer naturel chromophore et de tio2 en solution aqueuse [texte imprimé] / Lamia Mammeri, Auteur ; Tahar Sehili, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2016 . - 220 f.
2 copies imprimees disponibles
Langues : Français (fre)
Catégories : Français - Anglais
ChimieTags : Minerai naturel, photodégradation, radicaux hydroxyle, peroxyde d’hydrogène, acide
oxalique, photo-Fenton hétérogène.
Natural mineral, photodegradation, hydroxyl radicals, hydrogen peroxide, oxalic
acid, heterogeneous photo-Fenton.
خام طبيعي، التحلل الضوئي، جذور الهيدروكسيل، الماء الأكسجيني، حمض الأكزاليك، مفاعل فوتو فنتون في
وسط غير متجانسIndex. décimale : 540 Chimie et sciences connexes Résumé : This work was carried out in the field of water treatment using advanced oxidation processes
(AOPs), particularly the photocatalysis process in heterogeneous environments. The 1-Naphthol
(1-NP) was chosen as a model contaminant molecule to evaluate the photocatalytic performance
of a naturel mineral (NM).
In a homogeneous medium, the degradation of 1-NP has been studied by different
photochemical processes (UV254 nm, UV365 nm, solar irradiation and H2O2/UV254 nm) and by the
Fenton's reagent (Fe2+/H2O2). The performance comparison of the different processes studied
shows that the process of Fe2+/H2O2 is the most effective.
The 1-NP was degraded by heterogeneous photocatalysis using TiO2 and Fe2O3 as supporting
chromophores. This study showed the relative efficiency of the NM in inducing the 1-NP
photodegradation. The photodegradation kinetics are more important when using TiO2. In the
presence of NM, it appears that the •OH radicals are not involved in the degradation mechanism
of 1-NP.
Moreover, the study of the system 1-NP - NM - H2O2 showed that 1-NP disappears more
rapidly due to the intervention of the hydroxyl radicals generated by the Fenton and photoFenton reactions. The degradation rate depends on the concentration of hydrogen peroxide and
the pH of the medium.
It has also been observed that the addition of the oxalic acid in a NM solution significantly
enhances the rate of the degradation of the substrate similar to that of hydrogen peroxide. This
degradation is carried out by the oxidizing action of the hydroxyl radicals. However, the
alkalinization of the medium completely restrains the reaction.
Different natural irradiation tests have shown a more rapid degradation of the pollutant. This
environmentally friendly method appears to be very effective in the treatment of wastewater.Diplôme : Doctorat en sciences En ligne : ../theses/chimie/MAM6855.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10163 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité MAM/6855 MAM/6855 Thèse Bibliothèque principale Thèses Disponible
Titre : Dégradation photocatalytique des composés organiques en solution aqueuse en présence de TiO2 et des oxydes de fer. : Influence des acides carboxyliques. Type de document : texte imprimé Auteurs : Mohamed El Amine Kribéche, Auteur ; Tahar Sehili, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2016 Importance : 207 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
ChimieIndex. décimale : 540 Chimie et sciences connexes Résumé : The photodegradation of the herbicide phenylurea by using a natural iron oxide (NIO) α-Fe2O3 in
aqueous solution at acidic pH has been undertaken. The NIO was characterized by the Raman
spectroscopy method. The degradation pathways and the formation of by-products were studied. A
high-pressure mercury lamp and sunlight were employed as light source. Fenuron
photodegradation using NIO with oxalic acid followed the pseudo-first order kinetics, the optimal
experimental conditions were [oxalic acid] 0 = 10−3 M and [NIO] = 0.1 g L−1 at pH 3. NIO/oxalic
acid/UV system led to a low fenuron half-life (32 min). The results were even better when solar
light is used (15 min). The effect of four carboxylic acids; oxalic, citric, tartaric and malic acids on
the degradation efficiency was studied. Oxalic acid was the most effective carboxylic acid used on
the fenuron photodegradation with NIO at pH 3. The analytical study showed many aromatic
intermediates, short-chain carboxylic acids and inorganic ion.
The role of dissolved oxygen (DO) in degradation and mineralization of fenuron in the photo
Fenton-like system by using the NIO was also studied; the NIO was used as an iron source. The
DO effect has been elucidated by carrying out experiments with and without oxygen, it has been
found that the degradation and mineralization rate were strongly affected by change in DO
concentration. In absence of oxygen, there is no photo-Fenton-like because of the lack of hydrogen
peroxide, the degradation was caused only by the photo-reduction of Fe(III) complex in this case.
Oxygenation improved the hydrogen peroxide production under irradiation. The mass balance of
the reactive species showed that dissolved oxygen was the main reactive consumed during the
process. The toxicity decrease with irradiation time proves that the intermediates generated during
photo-oxidation by the photo-Fenton-like system by using a NIO are less toxic than fenuron.
Diplôme : Doctorat En ligne : ../theses/chimie/KRI6954.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10330 Dégradation photocatalytique des composés organiques en solution aqueuse en présence de TiO2 et des oxydes de fer. : Influence des acides carboxyliques. [texte imprimé] / Mohamed El Amine Kribéche, Auteur ; Tahar Sehili, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2016 . - 207 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
ChimieIndex. décimale : 540 Chimie et sciences connexes Résumé : The photodegradation of the herbicide phenylurea by using a natural iron oxide (NIO) α-Fe2O3 in
aqueous solution at acidic pH has been undertaken. The NIO was characterized by the Raman
spectroscopy method. The degradation pathways and the formation of by-products were studied. A
high-pressure mercury lamp and sunlight were employed as light source. Fenuron
photodegradation using NIO with oxalic acid followed the pseudo-first order kinetics, the optimal
experimental conditions were [oxalic acid] 0 = 10−3 M and [NIO] = 0.1 g L−1 at pH 3. NIO/oxalic
acid/UV system led to a low fenuron half-life (32 min). The results were even better when solar
light is used (15 min). The effect of four carboxylic acids; oxalic, citric, tartaric and malic acids on
the degradation efficiency was studied. Oxalic acid was the most effective carboxylic acid used on
the fenuron photodegradation with NIO at pH 3. The analytical study showed many aromatic
intermediates, short-chain carboxylic acids and inorganic ion.
The role of dissolved oxygen (DO) in degradation and mineralization of fenuron in the photo
Fenton-like system by using the NIO was also studied; the NIO was used as an iron source. The
DO effect has been elucidated by carrying out experiments with and without oxygen, it has been
found that the degradation and mineralization rate were strongly affected by change in DO
concentration. In absence of oxygen, there is no photo-Fenton-like because of the lack of hydrogen
peroxide, the degradation was caused only by the photo-reduction of Fe(III) complex in this case.
Oxygenation improved the hydrogen peroxide production under irradiation. The mass balance of
the reactive species showed that dissolved oxygen was the main reactive consumed during the
process. The toxicity decrease with irradiation time proves that the intermediates generated during
photo-oxidation by the photo-Fenton-like system by using a NIO are less toxic than fenuron.
Diplôme : Doctorat En ligne : ../theses/chimie/KRI6954.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10330 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité KRI/6954 KRI/6954 Thèse Bibliothèque principale Thèses Disponible
Titre : Dégradation photocatalytique de polluant pharmaceutique en présence des acides organiques et des métaux de transitions en solution aqueuse. Type de document : texte imprimé Auteurs : Mohamed El Hadi Benssassi, Auteur ; Tahar Sehili, Directeur de thèse Mention d'édition : 04-juil-21 Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2021 Importance : 179 f. Format : 30 cm. Note générale : Doctorat 3éme CYCLE LMD.
1 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
ChimieTags : Chime: Chimie Analytique et Environnement Paracétamol Photodégradation FeIII-Aspartate FeIII-Glutamate FeIII-Lactate Radicaux hydroxyle Paracetamol Photodegradation hydroxyl radicals الباراسيتامول التحلل الضوئي الجذور الهيدروكسيلية FeIII-Asp FeIII-Glu FeIII-Lac Index. décimale : 540 Chimie et sciences connexes Résumé :
The objective of this work is to study the photochemical fate of paracetamol or acetaminophen (PC) as a model pharmaceutical pollutant, in the presence of three iron complexes (FeIII-Aspartate, FeIII-Glutamate, or FeIII-Lactate) under irradiation at 365 nm. First, the FeIII complexes were characterized by UV-visible spectrophotometry; the results confirmed that these complexes are stable in the dark and at room temperature. Under irradiation at 365 nm, the photolysis of these complexes is relatively rapid: about 71% of the FeIII-Aspartate complex (t1/2 = 10.5 min, pH = 3.0) decomposed after 1 hour of irradiation, and about 73% (t½ = 6.2 min, pH = 3.40), and 91% (t½ = 6.4 min, pH = 3.0) in the case of the FeIII-Glutamate and FeIII-Lactate complex, respectively. In addition, this photochemical transformation depends on the wavelength of irradiation and pH. Direct photolysis of paracetamol under UVA irradiation showed a negligible effect, while the presence of FeIIIcomplexes favors the photodegradation of PC, which is faster in the presence of the FeIII-Lactate complex. Photodegradation was studied using various parameters such as initial pH, complex concentration, oxygen, and paracetamol concentration. The addition of T-BuOH as a hydroxyl radical scavenger and anaerobic conditions inhibit the photodegradation of PC, indicating that the photodegradation of paracetamol in the presence of FeIII-Asp, FeIII-Glu, or FeIII-Lact complexes is limited by the formation of hydrogen peroxide, the source of HO●. Seven transformation by-products have been identified by HPLC-MS, mainly hydroxylated derivatives. Reaction pathways are identified, highlighting the role of long-lived photoformed radicals. This study highlights the important role that organic iron complexes can play on the fate of pharmaceutical pollutants in the environment aquatic.
Diplôme : Doctorat En ligne : ../theses/chimie/BEN7775.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11609 Dégradation photocatalytique de polluant pharmaceutique en présence des acides organiques et des métaux de transitions en solution aqueuse. [texte imprimé] / Mohamed El Hadi Benssassi, Auteur ; Tahar Sehili, Directeur de thèse . - 04-juil-21 . - جامعة الإخوة منتوري قسنطينة, 2021 . - 179 f. ; 30 cm.
Doctorat 3éme CYCLE LMD.
1 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
ChimieTags : Chime: Chimie Analytique et Environnement Paracétamol Photodégradation FeIII-Aspartate FeIII-Glutamate FeIII-Lactate Radicaux hydroxyle Paracetamol Photodegradation hydroxyl radicals الباراسيتامول التحلل الضوئي الجذور الهيدروكسيلية FeIII-Asp FeIII-Glu FeIII-Lac Index. décimale : 540 Chimie et sciences connexes Résumé :
The objective of this work is to study the photochemical fate of paracetamol or acetaminophen (PC) as a model pharmaceutical pollutant, in the presence of three iron complexes (FeIII-Aspartate, FeIII-Glutamate, or FeIII-Lactate) under irradiation at 365 nm. First, the FeIII complexes were characterized by UV-visible spectrophotometry; the results confirmed that these complexes are stable in the dark and at room temperature. Under irradiation at 365 nm, the photolysis of these complexes is relatively rapid: about 71% of the FeIII-Aspartate complex (t1/2 = 10.5 min, pH = 3.0) decomposed after 1 hour of irradiation, and about 73% (t½ = 6.2 min, pH = 3.40), and 91% (t½ = 6.4 min, pH = 3.0) in the case of the FeIII-Glutamate and FeIII-Lactate complex, respectively. In addition, this photochemical transformation depends on the wavelength of irradiation and pH. Direct photolysis of paracetamol under UVA irradiation showed a negligible effect, while the presence of FeIIIcomplexes favors the photodegradation of PC, which is faster in the presence of the FeIII-Lactate complex. Photodegradation was studied using various parameters such as initial pH, complex concentration, oxygen, and paracetamol concentration. The addition of T-BuOH as a hydroxyl radical scavenger and anaerobic conditions inhibit the photodegradation of PC, indicating that the photodegradation of paracetamol in the presence of FeIII-Asp, FeIII-Glu, or FeIII-Lact complexes is limited by the formation of hydrogen peroxide, the source of HO●. Seven transformation by-products have been identified by HPLC-MS, mainly hydroxylated derivatives. Reaction pathways are identified, highlighting the role of long-lived photoformed radicals. This study highlights the important role that organic iron complexes can play on the fate of pharmaceutical pollutants in the environment aquatic.
Diplôme : Doctorat En ligne : ../theses/chimie/BEN7775.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11609 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité BEN/7775 BEN/7775 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
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