Elham Shokri; Reza Yegani
Abstract
In this study the efficiency of two different morphologies of polysulfone adsorptive membranes was examined for the humic acid removal from contaminated water. Adsorptive membranes with finger-like and sponge-like pore structures were prepared using modified montmorillonite with amino acid. Structure ...
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In this study the efficiency of two different morphologies of polysulfone adsorptive membranes was examined for the humic acid removal from contaminated water. Adsorptive membranes with finger-like and sponge-like pore structures were prepared using modified montmorillonite with amino acid. Structure of fabricated membranes was investigated by Field Emission-Scanning Electron Microscopy, pure water flux, porosity and contact angle measurement. The obtained results showed that the addition of modified montmorillonite (MMT) to the membrane with finger-like structure altered the morphology and improved pure water flux, porosity and hydrophilicity. These changes were negligible in PSf with sponge-like structure. In addition, the adsorption property of these membranes for the removal of humic acid (HA) was extensively studied. Adsorption capacity of cellular membrane was higher than the finger-like structure and Freundlich isotherm model was fitted for both of them. Nevertheless, the membrane with finger-like pores provides rapid adsorption of HA respect to cellular structure. It was also found that increasing the pH until pH=8 enhanced HA removal for adsorptive membranes, but increasing the pH above this point was not favorable. The obtained results from the dynamic adsorption revealed that sponge-like and finger-like membranes could generate 100 mL and 50 mL permeate of high quality (<1 ppm HA in water), respectively.
Milad Fonouni; Habib Etemadi; Reza Yegani; Masoumeh Safary Dehnavi; Naeime Jodeiry
Abstract
In this work, KClO3, K2Cr2O7 and KMnO4, dissolved in sulfuric acid, were used to functionalize microporous Polysulfone (PSf) membranes; fabricated by phase inversion method. The optimum concentrations of oxidizing agent and sulfuric acid and membrane immersion times were determined. FTIR results revealed ...
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In this work, KClO3, K2Cr2O7 and KMnO4, dissolved in sulfuric acid, were used to functionalize microporous Polysulfone (PSf) membranes; fabricated by phase inversion method. The optimum concentrations of oxidizing agent and sulfuric acid and membrane immersion times were determined. FTIR results revealed that the absorbance intensities of -OH and C=O peaks as well as the variety of functional groups in the samples treated by KClO3 are remarkably higher than in the samples treated by K2Cr2O7 and KMnO4, respectively. Bovine serum albumin (BSA) filtration experiments revealed that the total fouling ratio (TFR) and irreversible fouling ratio (IFR) decreased from 73.4% for pristine PSf membrane to 52.9%, 49.4% and 60.4% for treated membranes by Set A (K2Cr2O7), Set B (KClO3) and Set C (KMnO4), respectively. Moreover, IFR of membranes decreased from 45.4% for pristine PSf membrane to 29.9%, 22.4% and 36.1% for treated membranes by Set A, Set B and Set C, respectively.
Atefeh Tizchang; Yoones Jafarzadeh; Reza Yegani; Elham Shokri
Abstract
In this study, polysulfone (PSf) nanocomposite membranes embedded with functionalized nanodiamond (ND) were prepared via Non-Solvent Induced Phase Separation (NIPS) method. ND nanoparticles were silanized by using the esterification reaction of hydrolyzed vinyltrimethoxysilane (VTS) in alcoholic solution ...
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In this study, polysulfone (PSf) nanocomposite membranes embedded with functionalized nanodiamond (ND) were prepared via Non-Solvent Induced Phase Separation (NIPS) method. ND nanoparticles were silanized by using the esterification reaction of hydrolyzed vinyltrimethoxysilane (VTS) in alcoholic solution in order to enhance the compatibility between ND and PSf. Fourier Transform Infrared Spectroscopy (FTIR) analysis revealed that ND nanoparticles were successfully functionalized by silane groups. Nanocomposite membranes were then prepared with different percentages of silanized NDs (SNDs). The membranes were characterized using a set of analyses and the results showed that the addition of SNDs up to 1.0 wt.% resulted in an increase in hydrophilicity, water content, porosity and water flux of membranes. Moreover, Scanning Electron Microscopy (SEM) images indicated that the membrane with 1.0 wt. % nanoparticles had more pores on the membrane surface with smaller average pore size in comparison to other membranes. Antifouling properties of the membrane was also investigated in filtration of humic acid solution and the results showed that reversible fouling and flux recovery of membranes increased at the presence of SNDs.
Mahdi Seyfollahi; Habib Etemadi; Reza Yegani; Mahyar Rabeii; Elham Shokri
Abstract
In this study, membranes were prepared by pristine and polyethylene glycol (PEG)-grafted nanodiamond (ND) embedded in cellulose acetate (CA) as matrix polymer via non-solvent induced phase separation method. The antifouling properties of the membranes were studied during filtration of ...
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In this study, membranes were prepared by pristine and polyethylene glycol (PEG)-grafted nanodiamond (ND) embedded in cellulose acetate (CA) as matrix polymer via non-solvent induced phase separation method. The antifouling properties of the membranes were studied during filtration of bovine serum albumin (BSA) solutions and the governing fouling mechanisms of the membranes were also investigated using the Hermia model. Fourier Transform Infrared Spectroscopy (FTIR) and Thermal gravimetric analysis (TGA) confirmed that ND was successfully functionalized by PEG. CA/ND-PEG nanocomposite membranes have higher hydrophilicity, porosity, water uptake, mechanical strength and a lower amount of adsorbed protein than pure CA and CA/ND membranes. Besides, the antifouling performance of the CA/ND-PEG (0.5 wt.%) nanocomposite membrane also witnessed considerable improvement, in comparison with that of pure CA and CA/ND (0.5 wt.%) membranes. The obtained results showed that the best fit to experimental data for all membranes (pure and nanocomposite membranes) corresponds to the cake layer formation model.
Elham Shokri; Reza Yegani
Abstract
In this work, polysulfone (PSf) mixed matrix membranes were prepared by incorporating modified montmorillonite with lysine amino acid (MMT-Lys) for arsenic removal from water. Different tests including XRD, zeta potential, FE-SEM, contact angle, and pure water flux (PWF) were carried out to characterize ...
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In this work, polysulfone (PSf) mixed matrix membranes were prepared by incorporating modified montmorillonite with lysine amino acid (MMT-Lys) for arsenic removal from water. Different tests including XRD, zeta potential, FE-SEM, contact angle, and pure water flux (PWF) were carried out to characterize modified MMT and fabricated mixed matrix membranes. XRD analysis showed that MMT was successfully modified with Lys and its zeta potentials transferred from negative to positive after modification. Positive charge of MMT-Lys made it proper for anionic arsenic removal from water. The obtained results showed that pure water flux and surface hydrophilicity of the membranes improved as MMT-Lys contents increased from 0 to 1.5 wt.%. The batch adsorption of fabricated membranes as a function of arsenic initial concentration and solution pH was investigated. The removal efficiency was increased with increasing the arsenic initial concentration; however it was decreased with increasing pH of solution. The results also revealed that the arsenic adsorption was most favorable in the neutral pH. Moreover, membrane reusability of the PSf/MMT-Lys (1.5 wt.%) membrane was assessed by conducting five cycles of adsorption-desorption experiments in dead-end filtration. The obtained results showed the applicability of the prepared membrane for multiple cycles.