Problem statement: It is well documented that lead is one of contaminants of industrial wastewate... more Problem statement: It is well documented that lead is one of contaminants of industrial wastewaters and its pollution exists in the wastewater of many industries. As a result, recent research has focused on the development of cost effective alternatives using various natural sources and industrial wastes. In this setting, the use of low-cost agricultural materials, waste and residues for recovering heavy metals from contaminated industrial effluent has emerged as a potential alternative method to high cost adsorbents. In the present study, adsorption of lead(II) ions onto Orange Peel (OP), a typical agricultural byproduct, was investigated systematically with the variation in the parameters of pH, sorbent dosage, contact time and the initial concentration of adsorbate. Langmuir and Freundlich isotherms were used to analyze the equilibrium data. Kinetic and thermodynamic parameters were also calculated to describe the adsorption mechanism. Approach: The Orange Peel (OP) was obtained from a local market in the south of Jordan. The orange peel was cut into small pieces using scissors. Then OP was dried at 100°C for 24 h using hot air oven. Qualitative analyses of the main functional groups involved in metal adsorption were performed using a Fourier transformed infrared spectrometer (Perkin-Elmer FTIR 1605, ¨Uberlingen, Germany). Biosorption experiments were carried out in a thermostatic shaker at 180 rpm and at an ambient temperature (20±2°C) using 250 mL shaking flasks containing 100 mL of different concentrations and initial pH values of Pb(II) solutions, prepared from reagent grade salt Pb(NO 3) 2 (Merck). The initial pH values of the solutions were previously adjusted with 0.1 M HNO 3 or NaOH and measured using a hand held pH meters (315i/SET). The sorbent (0.2-1.0 g) was added to each flask and then the flasks were sealed up to prevent change of volume of the solution during the experiments. After shaking the flasks for predetermined time intervals, the samples were withdrawn from the flasks and filtered through a Whatman filter paper. The filtrate was analyzed by AAS (Perkin Elmer Analyst 300). Results: Four kinetic models are the pseudo-first-order, pseudo-second-order, Elovich and intraparticle diffusion equations, were selected to interpret the adsorption data. Kinetic parameters such as the rate constants, equilibrium adsorption capacities and related correlation coefficients, for each kinetic model were calculated and discussed. The linear Langmuir and Freundlich models were applied to describe equilibrium isotherms and both models fitted well. The monolayer adsorption capacity was found as 21.1 mg g −1 at pH 6 and 20°C.The dimensionless separation factor (R L) has shown that orange peel can be used for removal of Pb(II) from aqueous solutions. The nagative free energy of adsorption indicated that the adsorption of lead (II) ions onto orange peel was feasible and spontaneous. Conclusion: The sorption capacity of the orange peel is comparable to the other available adsorbents and it is quite cheaper.
The present work consists in the study of the modification of a nano-layered vermiculite by therm... more The present work consists in the study of the modification of a nano-layered vermiculite by thermal treatment up to 900°C. Changes in the structure and texture after thermal treatment were used for evaluation of dehydration properties of the studied material. The dehydration properties of the clay are strongly affected by the crystal structure. The Differential Thermal Analysis (DTA) allows the determination of the specific temperatures at which phase modifications take place, principally the ones attributed to the removal of the interlayer water molecules and the formation of a series of less hydrated phases. Structural and textural studies were carried out using Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) analysis. The SEM micrographs reveal structural changes of the sample, such as exfoliation phenomena and contraction of the vermiculite, related to the heating temperature. These observations are confirmed by the XRD patterns, which demonstrate that the d-spacing of the first basal diffraction varies depending on the applied heating temperature, this showing several states of dehydration. As a complementary characterization, porosity analysis by Hg-porosimetry has also been carried out.
The present work consists in the study of the modification of a nano-layered vermiculite by therm... more The present work consists in the study of the modification of a nano-layered vermiculite by thermal treatment up to 900°C. Changes in the structure and texture after thermal treatment were used for evaluation of dehydration properties of the studied material. The dehydration properties of the clay are strongly affected by the crystal structure. The Differential Thermal Analysis (DTA) allows the determination of the specific temperatures at which phase modifications take place, principally the ones attributed to the removal of the interlayer water molecules and the formation of a series of less hydrated phases. Structural and textural studies were carried out using Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) analysis. The SEM micrographs reveal structural changes of the sample, such as exfoliation phenomena and contraction of the vermiculite, related to the heating temperature. These observations are confirmed by the XRD patterns, which demonstrate that the d-spacing of the first basal diffraction varies depending on the applied heating temperature, this showing several states of dehydration. As a complementary characterization, porosity analysis by Hg-porosimetry has also been carried out.
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2005
Al-pillared clays were prepared by a reaction of Na-ghassoulite (Na-Gh) with base-hydrolyzed solu... more Al-pillared clays were prepared by a reaction of Na-ghassoulite (Na-Gh) with base-hydrolyzed solutions of Al3+ salts and a subsequent thermal conversion of the intercalated polycations. These pillared clays have relatively low micropore volumes. By preadsorption of amines between the clay layers prior to pillaring with aluminium precursor, it was possible to increase the microporosity of the obtained material. This improvement can be explained by the decrease of the Al-pillars density between the clay sheets. This explanation was proved by the decrease of the aluminium amounts in the treated samples determined by chemical analyses. The amount of amine was successively 1/4, 1/2 and 3/4 of the cation exchange capacity of the clay mineral.As a result, the pillar density decreases because a part of the interlayer space is occupied by the amine and during the calcination, the pillaring precursors are converted into rigid aluminum oxide pillars and the organic compounds are removed reflecting an improvement in the orientation of the clay layers. The surface area of this product increase to reach 624m2g−1 and the micropore volume becomes three times higher than that prepared without preadsorption of diethylamine.
The present work consists in the study of the modification of a nano-layered vermiculite by therm... more The present work consists in the study of the modification of a nano-layered vermiculite by thermal treatment up to 900 °C. Changes in the structure and texture after thermal treatment were used for evaluation of dehydration properties of the studied material. The dehydration properties of the clay are strongly affected by the crystal structure.The Differential Thermal Analysis (DTA) allows the determination
In this paper, we present an analysis of the adsorbed amounts and adsorption heats of water vapou... more In this paper, we present an analysis of the adsorbed amounts and adsorption heats of water vapour of Ca2+ Camp–Berteau montmorillonite. Measurements were obtained at 298K using thermogravimetry and calorimetry as a function of relative pressure and the study was completed by the adsorption of nitrogen at 77K. Experimental data were analysed with BET and t-method theories and compared with
This work reports the application of an activated clay mineral as adsorbent for the removal of a ... more This work reports the application of an activated clay mineral as adsorbent for the removal of a basic dye, methylene blue (MB), from aqueous solutions. The thermal treatment at 300°C for 2h and the acid activation with nitric acid of 0.5mol/dm3 under reflux conditions improve the adsorption capacity of the raw clay mineral. A maximum of 500mg/g of MB at
Characterization of the textural and structural properties of a sodium form of a delaminated calc... more Characterization of the textural and structural properties of a sodium form of a delaminated calcic montmorillonite, and of aluminium pillared materials prepared with and without amine pre-adsorption, was made using the adsorption of different probe molecules (nitrogen, ...
Problem statement: It is well documented that lead is one of contaminants of industrial wastewate... more Problem statement: It is well documented that lead is one of contaminants of industrial wastewaters and its pollution exists in the wastewater of many industries. As a result, recent research has focused on the development of cost effective alternatives using various natural sources and industrial wastes. In this setting, the use of low-cost agricultural materials, waste and residues for recovering heavy metals from contaminated industrial effluent has emerged as a potential alternative method to high cost adsorbents. In the present study, adsorption of lead(II) ions onto Orange Peel (OP), a typical agricultural byproduct, was investigated systematically with the variation in the parameters of pH, sorbent dosage, contact time and the initial concentration of adsorbate. Langmuir and Freundlich isotherms were used to analyze the equilibrium data. Kinetic and thermodynamic parameters were also calculated to describe the adsorption mechanism. Approach: The Orange Peel (OP) was obtained from a local market in the south of Jordan. The orange peel was cut into small pieces using scissors. Then OP was dried at 100°C for 24 h using hot air oven. Qualitative analyses of the main functional groups involved in metal adsorption were performed using a Fourier transformed infrared spectrometer (Perkin-Elmer FTIR 1605, ¨Uberlingen, Germany). Biosorption experiments were carried out in a thermostatic shaker at 180 rpm and at an ambient temperature (20±2°C) using 250 mL shaking flasks containing 100 mL of different concentrations and initial pH values of Pb(II) solutions, prepared from reagent grade salt Pb(NO 3) 2 (Merck). The initial pH values of the solutions were previously adjusted with 0.1 M HNO 3 or NaOH and measured using a hand held pH meters (315i/SET). The sorbent (0.2-1.0 g) was added to each flask and then the flasks were sealed up to prevent change of volume of the solution during the experiments. After shaking the flasks for predetermined time intervals, the samples were withdrawn from the flasks and filtered through a Whatman filter paper. The filtrate was analyzed by AAS (Perkin Elmer Analyst 300). Results: Four kinetic models are the pseudo-first-order, pseudo-second-order, Elovich and intraparticle diffusion equations, were selected to interpret the adsorption data. Kinetic parameters such as the rate constants, equilibrium adsorption capacities and related correlation coefficients, for each kinetic model were calculated and discussed. The linear Langmuir and Freundlich models were applied to describe equilibrium isotherms and both models fitted well. The monolayer adsorption capacity was found as 21.1 mg g −1 at pH 6 and 20°C.The dimensionless separation factor (R L) has shown that orange peel can be used for removal of Pb(II) from aqueous solutions. The nagative free energy of adsorption indicated that the adsorption of lead (II) ions onto orange peel was feasible and spontaneous. Conclusion: The sorption capacity of the orange peel is comparable to the other available adsorbents and it is quite cheaper.
The present work consists in the study of the modification of a nano-layered vermiculite by therm... more The present work consists in the study of the modification of a nano-layered vermiculite by thermal treatment up to 900°C. Changes in the structure and texture after thermal treatment were used for evaluation of dehydration properties of the studied material. The dehydration properties of the clay are strongly affected by the crystal structure. The Differential Thermal Analysis (DTA) allows the determination of the specific temperatures at which phase modifications take place, principally the ones attributed to the removal of the interlayer water molecules and the formation of a series of less hydrated phases. Structural and textural studies were carried out using Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) analysis. The SEM micrographs reveal structural changes of the sample, such as exfoliation phenomena and contraction of the vermiculite, related to the heating temperature. These observations are confirmed by the XRD patterns, which demonstrate that the d-spacing of the first basal diffraction varies depending on the applied heating temperature, this showing several states of dehydration. As a complementary characterization, porosity analysis by Hg-porosimetry has also been carried out.
The present work consists in the study of the modification of a nano-layered vermiculite by therm... more The present work consists in the study of the modification of a nano-layered vermiculite by thermal treatment up to 900°C. Changes in the structure and texture after thermal treatment were used for evaluation of dehydration properties of the studied material. The dehydration properties of the clay are strongly affected by the crystal structure. The Differential Thermal Analysis (DTA) allows the determination of the specific temperatures at which phase modifications take place, principally the ones attributed to the removal of the interlayer water molecules and the formation of a series of less hydrated phases. Structural and textural studies were carried out using Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) analysis. The SEM micrographs reveal structural changes of the sample, such as exfoliation phenomena and contraction of the vermiculite, related to the heating temperature. These observations are confirmed by the XRD patterns, which demonstrate that the d-spacing of the first basal diffraction varies depending on the applied heating temperature, this showing several states of dehydration. As a complementary characterization, porosity analysis by Hg-porosimetry has also been carried out.
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2005
Al-pillared clays were prepared by a reaction of Na-ghassoulite (Na-Gh) with base-hydrolyzed solu... more Al-pillared clays were prepared by a reaction of Na-ghassoulite (Na-Gh) with base-hydrolyzed solutions of Al3+ salts and a subsequent thermal conversion of the intercalated polycations. These pillared clays have relatively low micropore volumes. By preadsorption of amines between the clay layers prior to pillaring with aluminium precursor, it was possible to increase the microporosity of the obtained material. This improvement can be explained by the decrease of the Al-pillars density between the clay sheets. This explanation was proved by the decrease of the aluminium amounts in the treated samples determined by chemical analyses. The amount of amine was successively 1/4, 1/2 and 3/4 of the cation exchange capacity of the clay mineral.As a result, the pillar density decreases because a part of the interlayer space is occupied by the amine and during the calcination, the pillaring precursors are converted into rigid aluminum oxide pillars and the organic compounds are removed reflecting an improvement in the orientation of the clay layers. The surface area of this product increase to reach 624m2g−1 and the micropore volume becomes three times higher than that prepared without preadsorption of diethylamine.
The present work consists in the study of the modification of a nano-layered vermiculite by therm... more The present work consists in the study of the modification of a nano-layered vermiculite by thermal treatment up to 900 °C. Changes in the structure and texture after thermal treatment were used for evaluation of dehydration properties of the studied material. The dehydration properties of the clay are strongly affected by the crystal structure.The Differential Thermal Analysis (DTA) allows the determination
In this paper, we present an analysis of the adsorbed amounts and adsorption heats of water vapou... more In this paper, we present an analysis of the adsorbed amounts and adsorption heats of water vapour of Ca2+ Camp–Berteau montmorillonite. Measurements were obtained at 298K using thermogravimetry and calorimetry as a function of relative pressure and the study was completed by the adsorption of nitrogen at 77K. Experimental data were analysed with BET and t-method theories and compared with
This work reports the application of an activated clay mineral as adsorbent for the removal of a ... more This work reports the application of an activated clay mineral as adsorbent for the removal of a basic dye, methylene blue (MB), from aqueous solutions. The thermal treatment at 300°C for 2h and the acid activation with nitric acid of 0.5mol/dm3 under reflux conditions improve the adsorption capacity of the raw clay mineral. A maximum of 500mg/g of MB at
Characterization of the textural and structural properties of a sodium form of a delaminated calc... more Characterization of the textural and structural properties of a sodium form of a delaminated calcic montmorillonite, and of aluminium pillared materials prepared with and without amine pre-adsorption, was made using the adsorption of different probe molecules (nitrogen, ...
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Papers by Rabii Mahboub