Fadila Darragi - Academia.edu (original) (raw)
Papers by Fadila Darragi
This research involved the efficient adsorption of an anionic dye (Reactive Red 120) by natural u... more This research involved the efficient adsorption of an anionic dye (Reactive Red 120) by natural untreated clay, a low-cost material abundant in highly weathered soils. The adsorption kinetics was investigated using the parameters such as contact time, stirring speed, initial dye concentration, initial pH, ionic strength, and solution temperature. According to these experiments the maximum removal is observed after 80
Environmental Earth Sciences, 2010
Environmental Earth Sciences, 2012
... in Tunisian and Moroccan Mediterranean coastal lagoon sediments Joëlle Duplay • Khadija Semhi... more ... in Tunisian and Moroccan Mediterranean coastal lagoon sediments Joëlle Duplay • Khadija Semhi • Mohamed Karim Bloundi • Slim Khedhiri • Rabia Ben Ahmed • Fadila Darragi Received: 10 May 2011 / Accepted: 13 January 2012 Ó Springer-Verlag 2012 ...
International Journal of Environmental Studies, 2013
Desalination, 2011
This research involved the efficient adsorption of an anionic dye (Reactive Red 120) by natural u... more This research involved the efficient adsorption of an anionic dye (Reactive Red 120) by natural untreated clay, a low-cost material abundant in highly weathered soils. The adsorption kinetics was investigated using the parameters such as contact time, stirring speed, initial dye concentration, initial pH, ionic strength, and solution temperature. According to these experiments the maximum removal is observed after 80
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2012
Clay minerals are efficient adsorbent for dyes due to their colloidal properties. A Tunisian raw ... more Clay minerals are efficient adsorbent for dyes due to their colloidal properties. A Tunisian raw clay (Fouchana) composed of different species of clay minerals (kaolinite, smectite and minor illite) has shown efficiency for removal of anionic dye Reactive Red 120 (RR120) from aqueous solutions. In order to provide a better understanding of the role played by the different clay species in Fouchana, as well as the nature of the adsorption processes which are involved, a comparative study was conducted using standard clays, namely kaolinite KGa-2, smectite SWy-1 and illite IMt-2. Batch adsorption experiments were performed at ambient temperature and pH of the dye solutions. Acido-basic properties of the solid surfaces, electrophoretic mobility of particles, cation exchange capacity, amount of exchangeable cations and specific surface were investigated. Principal component analysis was used to highlight the influence of the physicochemical characteristics of the clay minerals in the adsorption behavior. The results show that for the conditions set in this study, kaolinite in the Fouchana raw clay plays a major role in anionic dye adsorption, mainly due to its acidic surface sites, but also to exchangeable aluminum (III) cations acting as bridges between the clay mineral and the dye molecules. Smectite and illite most likely play a secondary role by adsorption on exchangeable calcium (II) and dissociated Al (III) OH groups.
Microscopy Research and Technique, 2008
In the present work, we propose the use of the Laser Scanning Confocal Microscopy (LSCM) to deter... more In the present work, we propose the use of the Laser Scanning Confocal Microscopy (LSCM) to determine the effect of water repellents on rock's pore-network configuration and interconnection. The rocks studied are sandstones of Miocene age, a building material that is commonly found in the architectural heritage of Tunisia. The porosity quantitative data of treated and untreated samples, obtained by mercury porosimetry tests, were compared. The results show a slight decrease in total porosity with the water repellent treatment, which reduced both microporosity and macroporosity. This reduction produced a modification in pore size distribution and a shift of the pore access size mode interval toward smaller pore diameters (from the 30-40 lm to the 20-30 lm intervals). The water repellent was observed in SEM images as a continuous film coating grain surfaces; moreover, it was easily visualized in LSCM, by staining the water repellent with Epodye fluorochrome, and the coating thickness was straightforwardly measured (1.5-2 lm). In fact, the combination of mercury intrusion porosimetry data and LSCM observations suggests that the porosity reduction and the shift of the pore diameter mode were mainly due to the general reduction of pore diameters, but also to the plugging of the smallest pores (less than 3-4 lm in diameter) by the water repellent film. Finally, the LSCM technique enabled the reconstruction of 3D views of the water repellent coating film in the pore network, indicating that its distribution was uniform and continuous over the 100 lm thick sample. The LSCM imaging facilitates the integration and interpretation of mercury porosimetry and SEM data. Microsc. Res. Tech. 71:816-821,
This research involved the efficient adsorption of an anionic dye (Reactive Red 120) by natural u... more This research involved the efficient adsorption of an anionic dye (Reactive Red 120) by natural untreated clay, a low-cost material abundant in highly weathered soils. The adsorption kinetics was investigated using the parameters such as contact time, stirring speed, initial dye concentration, initial pH, ionic strength, and solution temperature. According to these experiments the maximum removal is observed after 80
Environmental Earth Sciences, 2010
Environmental Earth Sciences, 2012
... in Tunisian and Moroccan Mediterranean coastal lagoon sediments Joëlle Duplay • Khadija Semhi... more ... in Tunisian and Moroccan Mediterranean coastal lagoon sediments Joëlle Duplay • Khadija Semhi • Mohamed Karim Bloundi • Slim Khedhiri • Rabia Ben Ahmed • Fadila Darragi Received: 10 May 2011 / Accepted: 13 January 2012 Ó Springer-Verlag 2012 ...
International Journal of Environmental Studies, 2013
Desalination, 2011
This research involved the efficient adsorption of an anionic dye (Reactive Red 120) by natural u... more This research involved the efficient adsorption of an anionic dye (Reactive Red 120) by natural untreated clay, a low-cost material abundant in highly weathered soils. The adsorption kinetics was investigated using the parameters such as contact time, stirring speed, initial dye concentration, initial pH, ionic strength, and solution temperature. According to these experiments the maximum removal is observed after 80
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2012
Clay minerals are efficient adsorbent for dyes due to their colloidal properties. A Tunisian raw ... more Clay minerals are efficient adsorbent for dyes due to their colloidal properties. A Tunisian raw clay (Fouchana) composed of different species of clay minerals (kaolinite, smectite and minor illite) has shown efficiency for removal of anionic dye Reactive Red 120 (RR120) from aqueous solutions. In order to provide a better understanding of the role played by the different clay species in Fouchana, as well as the nature of the adsorption processes which are involved, a comparative study was conducted using standard clays, namely kaolinite KGa-2, smectite SWy-1 and illite IMt-2. Batch adsorption experiments were performed at ambient temperature and pH of the dye solutions. Acido-basic properties of the solid surfaces, electrophoretic mobility of particles, cation exchange capacity, amount of exchangeable cations and specific surface were investigated. Principal component analysis was used to highlight the influence of the physicochemical characteristics of the clay minerals in the adsorption behavior. The results show that for the conditions set in this study, kaolinite in the Fouchana raw clay plays a major role in anionic dye adsorption, mainly due to its acidic surface sites, but also to exchangeable aluminum (III) cations acting as bridges between the clay mineral and the dye molecules. Smectite and illite most likely play a secondary role by adsorption on exchangeable calcium (II) and dissociated Al (III) OH groups.
Microscopy Research and Technique, 2008
In the present work, we propose the use of the Laser Scanning Confocal Microscopy (LSCM) to deter... more In the present work, we propose the use of the Laser Scanning Confocal Microscopy (LSCM) to determine the effect of water repellents on rock's pore-network configuration and interconnection. The rocks studied are sandstones of Miocene age, a building material that is commonly found in the architectural heritage of Tunisia. The porosity quantitative data of treated and untreated samples, obtained by mercury porosimetry tests, were compared. The results show a slight decrease in total porosity with the water repellent treatment, which reduced both microporosity and macroporosity. This reduction produced a modification in pore size distribution and a shift of the pore access size mode interval toward smaller pore diameters (from the 30-40 lm to the 20-30 lm intervals). The water repellent was observed in SEM images as a continuous film coating grain surfaces; moreover, it was easily visualized in LSCM, by staining the water repellent with Epodye fluorochrome, and the coating thickness was straightforwardly measured (1.5-2 lm). In fact, the combination of mercury intrusion porosimetry data and LSCM observations suggests that the porosity reduction and the shift of the pore diameter mode were mainly due to the general reduction of pore diameters, but also to the plugging of the smallest pores (less than 3-4 lm in diameter) by the water repellent film. Finally, the LSCM technique enabled the reconstruction of 3D views of the water repellent coating film in the pore network, indicating that its distribution was uniform and continuous over the 100 lm thick sample. The LSCM imaging facilitates the integration and interpretation of mercury porosimetry and SEM data. Microsc. Res. Tech. 71:816-821,