Sedigheh Daroumi; Mohammad Ali Aroon; Ramin Yavari; taher yousefi; Hossein Ghasemi mobtaker
Abstract
In this study, the flat sheet membranes including the neat polyethersulfone (PES) and the mixed matrix membranes (MMMs) containing 20 wt. % polyethersulfone (PES) and various amounts of Fe3O4 nanoparticles were prepared using wet phase inversion and conventional casting methods. Manganese ion rejection ...
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In this study, the flat sheet membranes including the neat polyethersulfone (PES) and the mixed matrix membranes (MMMs) containing 20 wt. % polyethersulfone (PES) and various amounts of Fe3O4 nanoparticles were prepared using wet phase inversion and conventional casting methods. Manganese ion rejection and permeate flux as a performance evaluation of the prepared membranes was studied and compared. The characteristics of the fabricated membranes and the synthesized nanoparticles were fulfilled by transmission electron microscopy, field emission scanning electron microscopy and contact angle measurement. The operational parameters such as polymer concentration, pressure, pH, manganese ion concentration and time for manganese ion rejection and permeability were firstly optimized on the neat PES membrane. In the next steps, the performance of the fabricated MMMs containing various amount of Fe3O4 nanoparticles and PES (20%wt.) was evaluated and compared under these optimized conditions. Under the optimal conditions obtained for the rejection of manganese ions by neat PES, the fabricated MMMs had better performance than the neat PES membrane. Also, the results showed that the best performance of the prepared MMMs with the manganese rejection percentage of 89.3% and permeate flux of 28.7 L.m-2.h was found to belong to the PES membranes containing 0.1 wt.% of Fe3O4.
Noorallah Delijeh; Taher Yousefi; Hasan Aghayan; Ramin Yavari; Mehdi Parvini; Hossein Ghasemi mobtaker
Abstract
In the current work synthesis and modification of graphene oxide with Nickel Hexa Ferrocyanide (NiHCF) nanoparticles has been reported. The Graphene oxide- Nickel Hexa Ferrocyanide (GO-NiHCF) was used as an adsorbent to remove Cesium (Cs) ions from a simulated solution. The obtained product was characterized ...
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In the current work synthesis and modification of graphene oxide with Nickel Hexa Ferrocyanide (NiHCF) nanoparticles has been reported. The Graphene oxide- Nickel Hexa Ferrocyanide (GO-NiHCF) was used as an adsorbent to remove Cesium (Cs) ions from a simulated solution. The obtained product was characterized with XRD, SEM, TGA, FTIR, and BET techniques. The SEM images and XRD pattern confirms the successful immobilization of Nickel Hexa Ferrocyanide on graphene oxide sheet. The cesium removal ability of GO-NiHCF was evaluated in batch mode. Effect of various parameters such as pH, initial concentration, contact time, and interferences ions were studied. The results cleared that the maximum adsorption for Cs removal was 240 mg g-1. Equilibrium modeling studies suggest that the data are reasonably and relatively fitted well to the Langmuir adsorption isotherm. Kinetic studies show that sorption process is fairly rapid and the kinetic data are fitted well to the pseudo-second order rate model. This composite offers strong potential in the field of elimination of Cs that requires rapid and complete decontamination.
Taher Yousefi; Ramin Yavari; D Rezaei Uchbelagh; Abbas Ariamanesh
Abstract
Al-Ce-Mn oxide samples were synthesized by the cathodic electrochemical method at current densities of 5, 15, and 35 mAcm-2. The XRD, SEM, and EDX techniques were used for the characterization of samples. The SEM images show that at high current density the one-dimensional(nanowire) structure and at ...
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Al-Ce-Mn oxide samples were synthesized by the cathodic electrochemical method at current densities of 5, 15, and 35 mAcm-2. The XRD, SEM, and EDX techniques were used for the characterization of samples. The SEM images show that at high current density the one-dimensional(nanowire) structure and at low current density two-dimensional (nanosheet) structure were obtained. Moreover, the particle sizes are decreased with increasing the current density. The samples were applied for the uptake of fluorine (F-) ions from solutions. The influence of the contact time, initial fluoride concentration, and solution pH on the adsorption was investigated. The results showed more than 80 % of F- ions were uptake from solution during the three hours initial contact times and the uptake capacity has little change at pH below 6 and it has a sharp decline with increasing solution pH. The kinetic data were well fitted to the pseudo-second-order model and the equilibrium adsorption data was well described by the Langmuir isotherm model. The adsorption capacity was 48 mg/g at pH 6 and room temperature.
Seyed Hamed Mousavi; Fatemeh Ajoudani; Taher Yousefi; Amir Charkhi; Nima Rezaee Mojdehi; Ramin Yavari
Abstract
{[Dy(BTC)(H2O)]•DMF}n metal organic framework nanoparticles was synthezed through solvthermal method. The product was characterized by XRD, TG, BET, and SEM techniques. SEM images showed that the synthesized sample has semi-cubic particles with average size of 70 nm in length.For improve the gas ...
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{[Dy(BTC)(H2O)]•DMF}n metal organic framework nanoparticles was synthezed through solvthermal method. The product was characterized by XRD, TG, BET, and SEM techniques. SEM images showed that the synthesized sample has semi-cubic particles with average size of 70 nm in length.For improve the gas separation performance,the MOF nano particles were dispersed in polydimethylsiloxane (PDMS) for preparation of mixed matrix membrane (MMM) on support of polyethersulphone (PES). The performance of obtained MMM in separation of NO, N2 and O2 gas were investigated, and the effect of MOF nanoparticles (5, 10, and 15% wt)and feed pressure (100-250 kPa) on permeability and selectivity were studied. It was found that the membrane performance is evaluated by addition of MOF nano particles in membrane (polymeric matrix), and the feed pressure have not important effect on separation. The performance (NO/N2 and NO/O2 selectivity) increased as the loading of MOF particles (up to 15% wt) being dispersed within the polymer matrices.
Peghah Ghomashi; Amir Charkhi; Mohammad Kazemeini; Taher Yousefi
Abstract
In this study adsorption of fluoride ion from high-fluorine solutions (
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In this study adsorption of fluoride ion from high-fluorine solutions (
Saied Saeed Hosseiny Davarani; Hamid Reza Moazami; Taher Yousefi; Masoud Abrari
Abstract
A flexible route for the electrosynthesis of visible light active CdxZn1-xO nanostructures has been proposed. Various nanostructures were prepared by anodic dissolution in 0.1M Me4NCl by using an applied potential of 15V for 30min. The prepared nanostructures were characterized by diffuse reflectance ...
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A flexible route for the electrosynthesis of visible light active CdxZn1-xO nanostructures has been proposed. Various nanostructures were prepared by anodic dissolution in 0.1M Me4NCl by using an applied potential of 15V for 30min. The prepared nanostructures were characterized by diffuse reflectance UV-Vis spectroscopy (DRS), Fourier transforms infrared spectrometry (FT-IR), X-Ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that the crystalline structure, morphology, and energy band gap of the products can be finely adjusted only by varying the duty cycle of the anodeswitching. The visible light activity of the obtained nanostructures was investigated using methyl orange as a model organic pollutant. It was found that the proposed method can be used to obtain very effective CdxZn1-xO photocatalysts by fine tuning of the morphology and energy band gap. The prepared photocatalyst retained 80% of its original activity after 5 replicated uses.
Taher Yousefi; Mohammad Abas Mohsen; Hamid Reza Mahmudian; Meisam Torab-Mostaeidi; Mohammad Ali Moosavian; Hassan Aghayan
Abstract
In the current work, the natural zeolite was modified with cobalt hexacyanoferrate and employed for adsorbent of Pb(II) ions from aqueous solution. The modification was approved by XRD and FTIR techniques. The Pb(II) adsorption capacity enhanced by 1.8 times from 60 mg/g (natural zeolite) to 100 mg/g ...
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In the current work, the natural zeolite was modified with cobalt hexacyanoferrate and employed for adsorbent of Pb(II) ions from aqueous solution. The modification was approved by XRD and FTIR techniques. The Pb(II) adsorption capacity enhanced by 1.8 times from 60 mg/g (natural zeolite) to 100 mg/g (modified zeolite) at optimal conditions. Factors such as time, pH, temperature, adsorbent dosage and initial concentration were investigated to optimize the adsorption condition. A fast sorption was observed in the initial contact time and equilibrium was achieved in less than 120 min. The optimum pH for lead removal was between 3 and 6. The adsorption capacity was increased and reached the maximum of 90 % at 2 g/L adsorbent dosage. Also, the adsorption increased as the concentration increased up to 500 mg/L and the sorption became constant at higher concentration. It was found that the double-exponential model describes the lead sorption kinetics and the Langmuir–model describe the isotherms.
Taher Yousefi; Hamid Raza Moazami; Hamid Reza Mahmudian; Meisam Torab-Mostaedi; Mohammad Ali Moosavian
Abstract
In the current research work the Iranian natural zeolite (clinoptililite) was modified with Cobalt Hexacyanoferrate nanopatricles. The natural and Cobalt Hexacyanoferrat modifed zeolites were characterized by FTIR and SEM techniques and were empolyed as an adsorbent for removal Cd(II) ions from ...
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In the current research work the Iranian natural zeolite (clinoptililite) was modified with Cobalt Hexacyanoferrate nanopatricles. The natural and Cobalt Hexacyanoferrat modifed zeolites were characterized by FTIR and SEM techniques and were empolyed as an adsorbent for removal Cd(II) ions from aqueous sloution. The adsorption expriments were performed in bach mode. The Cd(II) sorption capacity of Cobalt Hexacyanoferrat modified zeolite was 51 mg g-1. The effect of influceing factors such as time, temperature and initial concentration were investigated. A fast sorption was observed in the initial contact time and equilibrium was achieved in less than 100 min. The equilibrium adsorption data for Cd (II) were better fitted to the Longmuir adsorption isotherm model. The increase in temperature has a slight positive effect on the uptake of Cd(II) ions. The results indicated that the Cobalt Hexacyanoferrate nanopatricles modified natural zeolite has effective potential for the adsorption of Cd(II) from the wastewater.
Taher Yousefi; Meisam Torab-Mostaedi; Amir Charkhi; Abolfazl Aghaei
Abstract
An uptake of Cd(II) from aqueous solutions by ion exchange on Iranian natural zeolitic (TOSKA) has been studied. Experiments were carried out using batch method as a function of the initial concentration of metal ions, contact time, and temperature. The adsorbent is characterized using XRF, FTIR, TEM, ...
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An uptake of Cd(II) from aqueous solutions by ion exchange on Iranian natural zeolitic (TOSKA) has been studied. Experiments were carried out using batch method as a function of the initial concentration of metal ions, contact time, and temperature. The adsorbent is characterized using XRF, FTIR, TEM, and XRD. The TEM images showed that the zeolite particle sizes are reduced into the size range of less than 90 nm by means of ball milling. The characterization of sample indicates that the natural zeolite used in this study was classified into clinoptilolite. Equilibrium modelling data were fitted to linear Langmuir and Freundlich models. Thermodynamics parameters such as change in free energy (ΔG◦), enthalpy (ΔH◦) and entropy (ΔS◦) were also calculated. The negative values obtained for ΔG◦ indicated that the sorption of Cd(II) on natural zeolite was spontaneous at all studied concentrations. These results show that natural zeolites hold great potential to remove Cd(II) from industrial wastewater.
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