2 résultat(s) recherche sur le tag 'ion exchange'    

Etude de l’Interaction des ions Cr(III) avec des Surfaces Solides dans l’Environnement et le Traitement des Eaux / Souad Merabet -Boumendjel  

Public ISBD Titre : Etude de l’Interaction des ions Cr(III) avec des Surfaces Solides dans l’Environnement et le Traitement des Eaux Type de document : texte imprimé Auteurs : Souad Merabet -Boumendjel, Auteur ; Chahrazed Boukhalfa- Djebbar, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2016 Importance : 167 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles Langues : Français (fre) Tags : chromium (III)  sediments  iron oxyhydroxide  aluminum oxyhydroxide  calcite  kaolinite  adsorption  coprecipitation  ion exchange  ?????? (  )III???????  ?????????????? ??????  ?????????????? ??????????  ????????  ??????? ???????  chrome(III)  sédiments  oxyhydroxyde de fer  oxyhydroxyde d’aluminium  coprécipitation  échange d’ions Index. décimale : 540 Chimie et sciences connexes Résumé : In the present work, the fixing of chromium (III) is studied using various solids encountered in aquatic environment and water treatment. In the environment, sediments were collected from Rhumel and Hemimim rivers located in Constantine city in the North East Algeria. Commercial solid were used (alumina, calcite, kaolinite and ion exchangers) and others were prepared (iron and aluminum oxyhydroxides). All solids were characterized by XRD and FTIR analysis. The fixing of Cr (III) ions was evaluated according to different parameters in static mode. Kinetic and equilibrium studies were performed. The obtained results show that for the used sediments, the binding capacity of Cr (III) ions is in relation to their constitution. The significant presence of quartz involves a decrease in fixing rates. The use of the different minerals encountered in the sediments shows that the fixing rate of chromium (III) increases in the order: kaolinite < calcite < alumina < ferrihydrite In all cases, fixing kinetic is best described by the second order model. The Temkin model is more appropriate to describe the fixing isotherms of chromium in the case of sediments. However, Langmuir and Freundlich models better describe in the case of ferrihydrite and alumina. In water treatment, the effectiveness of Cr (III) removal by the oxyhydroxides of Fe (III) or / and Al (III) freshly prepared depends largely on the water pH. It follows the order: Al (III) < Fe(III)/Al(III) < Fe(III). The maximum exchange capacity of IR120 and IRC 86 resins towards Cr (III) ions are 112mg/g and 23mg/g respectively. The interaction of Cr(III) ions with the two resins is controlled by a diffusion process. Note de contenu : Diplôme : Doctorat en sciences En ligne : ../theses/chimie/MER6914.pdf Format de la ressource électronique : pdf Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10266 Etude de l’Interaction des ions Cr(III) avec des Surfaces Solides dans l’Environnement et le Traitement des Eaux [texte imprimé] / Souad Merabet -Boumendjel, Auteur ; Chahrazed Boukhalfa- Djebbar, Directeur de thèse . - [S.l.] : جامعة الإخوة منتوري قسنطينة, 2016 . - 167 f. ; 30 cm. 2 copies imprimées disponibles Langues : Français (fre) Tags : chromium (III)  sediments  iron oxyhydroxide  aluminum oxyhydroxide  calcite  kaolinite  adsorption  coprecipitation  ion exchange  ?????? (  )III???????  ?????????????? ??????  ?????????????? ??????????  ????????  ??????? ???????  chrome(III)  sédiments  oxyhydroxyde de fer  oxyhydroxyde d’aluminium  coprécipitation  échange d’ions Index. décimale : 540 Chimie et sciences connexes Résumé : In the present work, the fixing of chromium (III) is studied using various solids encountered in aquatic environment and water treatment. In the environment, sediments were collected from Rhumel and Hemimim rivers located in Constantine city in the North East Algeria. Commercial solid were used (alumina, calcite, kaolinite and ion exchangers) and others were prepared (iron and aluminum oxyhydroxides). All solids were characterized by XRD and FTIR analysis. The fixing of Cr (III) ions was evaluated according to different parameters in static mode. Kinetic and equilibrium studies were performed. The obtained results show that for the used sediments, the binding capacity of Cr (III) ions is in relation to their constitution. The significant presence of quartz involves a decrease in fixing rates. The use of the different minerals encountered in the sediments shows that the fixing rate of chromium (III) increases in the order: kaolinite < calcite < alumina < ferrihydrite In all cases, fixing kinetic is best described by the second order model. The Temkin model is more appropriate to describe the fixing isotherms of chromium in the case of sediments. However, Langmuir and Freundlich models better describe in the case of ferrihydrite and alumina. In water treatment, the effectiveness of Cr (III) removal by the oxyhydroxides of Fe (III) or / and Al (III) freshly prepared depends largely on the water pH. It follows the order: Al (III) < Fe(III)/Al(III) < Fe(III). The maximum exchange capacity of IR120 and IRC 86 resins towards Cr (III) ions are 112mg/g and 23mg/g respectively. The interaction of Cr(III) ions with the two resins is controlled by a diffusion process. Note de contenu : Diplôme : Doctorat en sciences En ligne : ../theses/chimie/MER6914.pdf Format de la ressource électronique : pdf Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10266

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Etude de l’elimination des ions Cr(VI) par des procédés physico-chimiques application aux eaux de chromage / Imene Chaabna  

Public ISBD Titre : Etude de l’elimination des ions Cr(VI) par des procédés physico-chimiques application aux eaux de chromage Type de document : texte imprimé Auteurs : Imene Chaabna, Auteur ; Chahrazed Boukhalfa- Djebbar, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2017 Importance : 172 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles Langues : Français (fre) Tags : Cr(VI)  traitement des eaux  adsorption  échange d’ions  réduction  charbon actif  ferrihydrite  composite (charbon actif/fer)  Amberlite A21  Amberlite IRN78  eaux de chromage  water treatment  ion exchange  reduction  activated carbon  composite (activated carbon/iron)  chrome plating water  "?????? ???????  ?????? ??????  ????????  ??????? ???????  ???????  ??? ????  ???? (???- ???? ) Index. décimale : 540 Chimie et sciences connexes Résumé : The present work focuses on the development of effective, practical and inexpensive physico-chemical processes for the decontamination of water containing Cr (VI) ions. Adsorption removal was carried out using commercial activated charcoal, prepared ferrihydrite and composites (activated carbon/iron) prepared by precipitation of Fe (III) ions in the presence of coal at mass ratios (1/10) and 1/5). These adsorbents are characterized by DRX, ATR-FTIR, BET analysis, thermal analysis and by physicochemical analysis. The ion exchange removal is carried out using the Amberlite A21 resin (weak base type) and the Amberlite IRN78 resin (strong base type). The removal efficiency of Cr (VI) ions by precipitation after reduction is evaluated using ascorbic acid and sodium sulfite as reducing agents and soda and lime as precipitants. In synthetic solutions, macroscopic experiments of Cr (VI) ions removal are carried out in the absence and in the presence of competitives ions in batch and in column (according the case). kinetics, equilibrium and thermodynamics studies are carried out. The binding of Cr (VI) ions by adsorption is also studied through spectroscopic analysis. In chrome-plating waters, removal of Cr (VI) ions by these methods is evaluated as a function of pH The synthesized composites are characterized by the predominance of mesopores. Their specific surfaces are similar to that of ferrihydrite. Increasing the amount of iron involves increasing the content of basic functions and the formation of hematite. The results of macroscopic experiments show that whatever the method used, the maximum elimination of Cr (VI) ions is recorded at acidic pH. The effectiveness of sodium sulfite in reducing Cr (VI) ions decreases rapidly with increasing pH. The increase in temperature implies an increase in the elimination in the case of the resins and a decrease in the case of the adsorbents. The presence of competitive ions implies a decrease in the optimum pH range of the removal and a slowing down of adsorption and exchange processes. The removal efficiency of Cr (VI) ions by ferrihydrite, composites and resins is strongly influenced by the presence of sulfate ions. The spectroscopic analysis (ATR-FTIR) suggest that the mechanism of Cr (VI) uptake by ferrihydrite and composites depends on pH and the presence of competitive ions. At pH <6, Cr (VI) ions form inner-sphere surface complexes. Whatever the pH, the interaction of the Cr (VI) ions is essentially electrostatic in the presence of the competitive ions. In chrome-plating waters, the efficiencies of Cr (VI) removal by the used solids at pH: 3 follow the order: IRN78> CAC> CACFe (1/5)> Ferrihydrite. Diplôme : Doctorat En ligne : ../theses/chimie/CHA7019.pdf Format de la ressource électronique : pdf Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10421 Etude de l’elimination des ions Cr(VI) par des procédés physico-chimiques application aux eaux de chromage [texte imprimé] / Imene Chaabna, Auteur ; Chahrazed Boukhalfa- Djebbar, Directeur de thèse . - [S.l.] : جامعة الإخوة منتوري قسنطينة, 2017 . - 172 f. ; 30 cm. 2 copies imprimées disponibles Langues : Français (fre) Tags : Cr(VI)  traitement des eaux  adsorption  échange d’ions  réduction  charbon actif  ferrihydrite  composite (charbon actif/fer)  Amberlite A21  Amberlite IRN78  eaux de chromage  water treatment  ion exchange  reduction  activated carbon  composite (activated carbon/iron)  chrome plating water  "?????? ???????  ?????? ??????  ????????  ??????? ???????  ???????  ??? ????  ???? (???- ???? ) Index. décimale : 540 Chimie et sciences connexes Résumé : The present work focuses on the development of effective, practical and inexpensive physico-chemical processes for the decontamination of water containing Cr (VI) ions. Adsorption removal was carried out using commercial activated charcoal, prepared ferrihydrite and composites (activated carbon/iron) prepared by precipitation of Fe (III) ions in the presence of coal at mass ratios (1/10) and 1/5). These adsorbents are characterized by DRX, ATR-FTIR, BET analysis, thermal analysis and by physicochemical analysis. The ion exchange removal is carried out using the Amberlite A21 resin (weak base type) and the Amberlite IRN78 resin (strong base type). The removal efficiency of Cr (VI) ions by precipitation after reduction is evaluated using ascorbic acid and sodium sulfite as reducing agents and soda and lime as precipitants. In synthetic solutions, macroscopic experiments of Cr (VI) ions removal are carried out in the absence and in the presence of competitives ions in batch and in column (according the case). kinetics, equilibrium and thermodynamics studies are carried out. The binding of Cr (VI) ions by adsorption is also studied through spectroscopic analysis. In chrome-plating waters, removal of Cr (VI) ions by these methods is evaluated as a function of pH The synthesized composites are characterized by the predominance of mesopores. Their specific surfaces are similar to that of ferrihydrite. Increasing the amount of iron involves increasing the content of basic functions and the formation of hematite. The results of macroscopic experiments show that whatever the method used, the maximum elimination of Cr (VI) ions is recorded at acidic pH. The effectiveness of sodium sulfite in reducing Cr (VI) ions decreases rapidly with increasing pH. The increase in temperature implies an increase in the elimination in the case of the resins and a decrease in the case of the adsorbents. The presence of competitive ions implies a decrease in the optimum pH range of the removal and a slowing down of adsorption and exchange processes. The removal efficiency of Cr (VI) ions by ferrihydrite, composites and resins is strongly influenced by the presence of sulfate ions. The spectroscopic analysis (ATR-FTIR) suggest that the mechanism of Cr (VI) uptake by ferrihydrite and composites depends on pH and the presence of competitive ions. At pH <6, Cr (VI) ions form inner-sphere surface complexes. Whatever the pH, the interaction of the Cr (VI) ions is essentially electrostatic in the presence of the competitive ions. In chrome-plating waters, the efficiencies of Cr (VI) removal by the used solids at pH: 3 follow the order: IRN78> CAC> CACFe (1/5)> Ferrihydrite. Diplôme : Doctorat En ligne : ../theses/chimie/CHA7019.pdf Format de la ressource électronique : pdf Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10421

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