Reyhaneh Rahnama; Atena Shabani Afroozi; Mohammad Reza Jamali
Abstract
In the present work, an efficient method was developed for the determination of lead in natural water samples. In this method, lead was extracted by octanoic acid reverse micelles (bulk phase) and measured by flame atomic absorption spectroscopy (FAAS). Ligand 1-(2-Pyridylazo)-2-naphthol was used as ...
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In the present work, an efficient method was developed for the determination of lead in natural water samples. In this method, lead was extracted by octanoic acid reverse micelles (bulk phase) and measured by flame atomic absorption spectroscopy (FAAS). Ligand 1-(2-Pyridylazo)-2-naphthol was used as a chelating agent. In order to obtain the best extraction results, some experimental parameters (such as pH, ligand concentration, ionic strength, etc.) affecting the extraction efficiency were investigated and optimized. Under optimal conditions, the calibration curve was linear in the concentration range of 2.5-200.0 μgL-1 with a correlation coefficient of 0.9998. The detection limit was 0.8 μgL-1 and the preconcentration factor was 50. This method was successfully used to measure lead in natural water samples.
Ehsan Zolfonoun; Seyed Reza Yousefi
Abstract
A ligandless on-line solid phase extraction method was developed for the preconcentration of lead prior to quantitation by inductively coupled plasma-optical emission spectrometry. In this method, the sample solution was passed through a syringe membrane filter coated with graphitic carbon nitride and ...
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A ligandless on-line solid phase extraction method was developed for the preconcentration of lead prior to quantitation by inductively coupled plasma-optical emission spectrometry. In this method, the sample solution was passed through a syringe membrane filter coated with graphitic carbon nitride and Pb(II) ions were directly adsorbed on the surface of g-C3N4 particles. The adsorbed Pb(II) ions were subsequently eluted from the membrane and transferred directly into the ICP-OES nebulizer with nitric acid solution. Under the optimized conditions and preconcentration of 25 mL of sample, the enhancement factor of 110 and the detection limit of 0.12 μg L-1 were obtained. The proposed procedure was applied for the preconcentration and determination of lead in environmental water samples.
Fatemeh Sabermahani; Fariba Honarmand
Abstract
In this study, Magnetic Fe3O4-walnut sawdust nanocompositewas synthesized and used for removal of lead from aqueous solution. The size, structural, optical and morphological properties of nanoparticles have been analyzed by Scanning Electron Microscope )SEM) and Dynamic Light Scattering method. The effect ...
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In this study, Magnetic Fe3O4-walnut sawdust nanocompositewas synthesized and used for removal of lead from aqueous solution. The size, structural, optical and morphological properties of nanoparticles have been analyzed by Scanning Electron Microscope )SEM) and Dynamic Light Scattering method. The effect of pH, contact time, adsorbent dose, initial concentration, ionic strength and the effect of temperature on the adsorption was checked out in a batch process mode. Using the equilibrium constants obtained at different temperatures, the thermodynamic results parameters were calculated as ∆G, ∆H and ∆S. The thermodynamic parameters showed that the uptake of lead is spontaneous and endothermic. The data were fitted with the Langmuir and Freundlich equations to describe the adsorption equilibrium. The maximum adsorption capacity by using Langmuir equation was calculated 12.99 mg/g. The kinetic data followed by Pseudo second. Owing to such outstanding features, Magnetic Fe3O4-walnut sawdust nanocompositeproved the great potential in adsorption lead removal from aqueous solutions.
Fatemeh Sabermahani; Leyli Irannejad; Nosrat Madadi Mahani
Volume 5, Issue 1 , March 2018, , Pages 33-38
Abstract
Polyaniline/maghemite magnetic nanocomposite (PANI/γ -Fe2O3 MNC) was used as active agents for removal of lead ions from aqueous media. Chemical co-precipitation method was used to prepare the maghemite nanoparticles. Subsequently, the MNC was synthesized through polymerization of aniline. ...
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Polyaniline/maghemite magnetic nanocomposite (PANI/γ -Fe2O3 MNC) was used as active agents for removal of lead ions from aqueous media. Chemical co-precipitation method was used to prepare the maghemite nanoparticles. Subsequently, the MNC was synthesized through polymerization of aniline. It was characterized by FT-IR.The efficiency of this MNC was estimated for Pb (II) removal by using batch method. The results showed that optimum conditions for lead removal were found to be at pH of 6, adsorbent dosage of 0.04 g and equilibrium contact time of 90 min. The kinetic of adsorption system have been studied based on the assumption of a pseudo-second order rate law. The adsorption isotherms were examined. The Freundlich adsorption isotherm model was found to represent the equilibrium adsorption isotherm better than Langmuir isotherm. The thermodynamic studies indicated that the adsorption was spontaneous and endothermic process for lead.
Fatemeh Sabermahani; Fatemeh Ziaaddini; Zahra Hassani
Volume 3, Issue 2 , September 2016, , Pages 137-144
Abstract
Removal of Pb(II) and Zn(II) ions from aqueous solutions using naphthalene modified with 2-(3,4,5-trimethoxybenzylidene) malononitrile(TMBM) as synthetic adsorbent was investigated. It was characterized by FT-IR. Batch method was applied for testing of adsorption behavior. Adsorption experiments showed, ...
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Removal of Pb(II) and Zn(II) ions from aqueous solutions using naphthalene modified with 2-(3,4,5-trimethoxybenzylidene) malononitrile(TMBM) as synthetic adsorbent was investigated. It was characterized by FT-IR. Batch method was applied for testing of adsorption behavior. Adsorption experiments showed, the new sorbent has high selectivity and good adsorption for removal of lead and zinc ions from aqueous solutions. Equilibration time was 5 min for zinc and 15 min for lead. There was little effect of salt on removal of the ions. The maximum adsorption capacities for Pb(II) and Zn(II) were 88.5 and 38.9 mg g-1, respectively. The thermodynamic studies indicated that the adsorption was spontaneous, exothermic and endothermic process for lead and zinc, respectively.
