Mohsen Jahanshahi
Volume 1, Issue 1 , July 2016, , Pages 0-0
Marta Litynska; Nataliia Tolstopalova; Igor Astrelin
Abstract
Arsenic belongs to chemical elements, which are often found in natural waters and make it unsuitable for consumption without special treatment. Neutralization of arsenic pollutants of natural waters by converting them into insoluble form is one of the perspective methods of dearsenication. Precipitation ...
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Arsenic belongs to chemical elements, which are often found in natural waters and make it unsuitable for consumption without special treatment. Neutralization of arsenic pollutants of natural waters by converting them into insoluble form is one of the perspective methods of dearsenication. Precipitation (by iron or aluminium coagulants, lime) and adsorption (by oxides and hydroxides of iron, aluminium or manganese) are among the most popular dearsenication methods. The use of these chemicals entails the formation of poorly soluble arsenates. Since the possibility of the release of arsenic compounds into the water due to the dissolution of formed arsenates depends on its solubility under appropriate conditions, it is necessary to have information about the dependence of arsenates solubility on pH. According to the calculations the solubilities of arsenates of iron(III), aluminium, manganese(II) and calcium are highly dependent on pH. At pH<4, the solubilities of these arsenates increase in the sequence FeAsO4 – Mn3(AsO4)2 – AlAsO4 – Ca3(AsO4)2. Above рН 4 dependence changes and solubilities of these arsenates increase in the sequence FeAsO4 – AlAsO4 – Mn3(AsO4)2 – Ca3(AsO4)2.
Ahmed El Nemr; Mohamed A. Hassaan; Fedekar Fadel Madkour
Abstract
HPLC-MS/MS degradation mechanism of Direct Yellow 12 (DY-12) dye using O3 associated with UV was studied. The influent of different conditions such as pH, initial DY-12 dye concentration and reaction time were studied in a batch reactor method. The results revealed that the pH value and DY-12 initial ...
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HPLC-MS/MS degradation mechanism of Direct Yellow 12 (DY-12) dye using O3 associated with UV was studied. The influent of different conditions such as pH, initial DY-12 dye concentration and reaction time were studied in a batch reactor method. The results revealed that the pH value and DY-12 initial concentration controlled the removal process. The maximum color removal was achieved in alkaline condition (pH 9) as compared to neutral or acidic conditions. The color removal of DY-12 dye followed the first-order kinetics. When UV was applied with ozone simultaneously, the first order rate constant (kd) increased, and the time of dye decolorization shortened to 10 min for 200 ppm dye concentration. These results indicated that the application of UV can reduce the reaction time and dose of ozone. Gas chromatography-mass spectrum and HPLC-MS/MS analyses of the treated synthetic dye solution at the end of the treatment time showed no toxic organic compounds were detected. The COD decreased by more than 85% of the initial COD of the untreated DY-12 dye concentration.
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.
Bal Yadav; Ritesh Kumar; Ravindra Kumar; Subhasis Chaudhuri; Panchanan Pramanik
Abstract
This paper presents the synthesis, characterization of the nanocomposite of silver and chitosan polymer composite reinforced by cellulose fibre and its electrical behaviour in presence of water vapour. The coated paper has been characterized by XRD, IR, SEM and EDX techniques. The size of silver nanoparticles ...
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This paper presents the synthesis, characterization of the nanocomposite of silver and chitosan polymer composite reinforced by cellulose fibre and its electrical behaviour in presence of water vapour. The coated paper has been characterized by XRD, IR, SEM and EDX techniques. The size of silver nanoparticles is found to be around 9 nm and deposited uniformly. Chitosan, as well as cellulose, contain a hydrogen attached to electronegative nitrogen and oxygen. This gives a favourable environment for the formation of hydrogen bonds. IR peaks of the composite infer the intermolecular hydrogen bonding between the two constituents. The SEM pictures show that the coating of the fibres with nanoparticles is quite uniform. EDX analysis shows that the coated filter paper has sufficient amount of silver along with carbon and oxygen. The coated paper shows good sensitivity towards humidity. It gives excellent linearity in response with a concentration of water vapour after heat treatment of composite at 130 °C. The sensitivity of the sensor is 0.8 MΩ per unit of relative humidity. Sensing properties originate from protonic conductivity from adsorbed water molecule.
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.
Sedigeh Sabalanvand; Hossein Hazrati; abbas jafarizad; Yoones Jafarzadeh
Abstract
Many studies have been done to reduce the membrane fouling and to increase the quality of the effluent from membrane bioreactor (MBR). One of the most important researches in this filed is the use of adsorbents and nanoparticles in the biological system. In this study, the effects of Fe3O4 nanoparticles ...
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Many studies have been done to reduce the membrane fouling and to increase the quality of the effluent from membrane bioreactor (MBR). One of the most important researches in this filed is the use of adsorbents and nanoparticles in the biological system. In this study, the effects of Fe3O4 nanoparticles were investigated using COD, extracellular polymeric substances (EPS), soluble microbial products (SMP), flux, particle size distribution (PSD) and FTIR analysis. The COD test showed that the removal rate was 86.92% in MBR without Fe3O4 (R1) and 98.17% in MBR with Fe3O4 (R2). The amount of EPS and SMP in the reactor containing nanoparticles is lower than that of a non-nanoparticle reactor. Flux rate is higher in R2, so it can be said that the presence of nanoparticles has a positive effect of reducing the membrane fouling. Also, FTIR analysis showed that the amount of protein in the biologic system R2, which is the major membrane contaminant, is greater than R1.
Suresh Ghotekar; Ajay Savale; Shreyas Pansambal
Abstract
The aim of this study was to expand an ecofriendly route for the fabrication of spherical shape silver nanoparticles (AgNPs) using an aqueous extract of Leucaena leucocephala L. leaves to act as stabilizing and reducing agent. Several biomolecules present in plant extract are accountable for single step ...
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The aim of this study was to expand an ecofriendly route for the fabrication of spherical shape silver nanoparticles (AgNPs) using an aqueous extract of Leucaena leucocephala L. leaves to act as stabilizing and reducing agent. Several biomolecules present in plant extract are accountable for single step reduction of metal ions into nanoparticles. The synthesized AgNPs were characterized by X-ray diffraction (XRD) profile, Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Energy-dispersive X-ray spectroscopy (EDS) and Photoluminescence. Besides these, AgNPs evinced potent antibacterial, antimalarial and antimycobacterial activity against Pseudomonas aeruginosa, Streptococcus pyogenes, Staphylococcus aureus, Escherichia coli, Salmonella typhi, Bacillus subtilis, Plasmodium falciparum and Mycobacterium tuberculosis. The results suggest that the efficiently synthesized AgNPs can be used as potential candidates for various medicinal applications in bionanotechnology based industries.
Shimelis Kassahun; Zebene Kiflie; Dong Shin; Sam Park
Abstract
Although several studies concerning the preparation of nitrogen doped titanium dioxide visible-light active photocatalyst have already been reported, the effects of dopant concentration and calcination temperature have been rarely investigated. This paper focuses on the preparation of nitrogen ...
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Although several studies concerning the preparation of nitrogen doped titanium dioxide visible-light active photocatalyst have already been reported, the effects of dopant concentration and calcination temperature have been rarely investigated. This paper focuses on the preparation of nitrogen doped titanium dioxide (N-doped TiO2) under different calcination temperature and nitrogen dopant concentration synthesizes by sol-gel method. The physicochemical characteristics of the prepared samples were examined using X-ray photoelectron spectroscopy (XPS), X-ray diffractometer (XRD), Brunauer Emmett Teller (BET) analyzer, and UV-Vis spectrometer. Methylene blue was used in this study as a test chemical. The results demonstrated that the sample prepared under calcination temperature of 600 oC show 8.33 and 5.57 % of rutile TiO2 phase depends on the dopant concentration. Furthermore, the sample prepared at a lower calcination temperature of 400 oC and nitrogen to titanium (N/Ti) molar ratio of 2 and 6 exhibited larger specific surface area of 80.18 and 77.07 m2g-1, respectively. The photoactivity of the catalyst was also investigated on methylene blue decolorization using the different N-doped TiO2 sample. The experiments demonstrated that the sample prepared at higher N/Ti molar ratio (6) and lower calcination temperature (400 oC) demonstrates about 80 % efficiency under visible light. It was concluded that the higher photoactivity of the N-doped sample prepared at higher dopant concentration and lower calcination temperature is due to synergistic effects of higher surface area, smaller crystal size and higher nitrogen content in the crystal lattice of TiO2.
Shreyas Pansambal; Suresh Ghotekar; Sunil Shewale; Keshav Deshmukh; Nilesh Barde; Pranav Bardapurkar
Abstract
Magnetically separable silica-coated cobalt ferrite (CoFe2O4@SiO2) magnetic nanoparticles (MNPs) were synthesized by sol-gel auto combustion method. Silica matrix was employed to minimize the agglomeration and coarsening of the MNPs. The structural and morphological properties of the as-prepared nanocatalyst ...
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Magnetically separable silica-coated cobalt ferrite (CoFe2O4@SiO2) magnetic nanoparticles (MNPs) were synthesized by sol-gel auto combustion method. Silica matrix was employed to minimize the agglomeration and coarsening of the MNPs. The structural and morphological properties of the as-prepared nanocatalyst were investigated using XRD, EDX, TEM-SAED, FTIR, XPS and VSM techniques. Furthermore, these nanoparticles were used as an efficient nanocatalyst for simple, swift and one-pot synthesis of 5-aryl-1,2,4-triazolidine-3-thione derivatives. The reaction steps include imine formation, cyclization, condensation and aromatization without use of any oxidizing or reducing reagents. The present methodology offers remarkable merits like shorter reaction time, mild reaction conditions, excellent yield, simplicity, safer reaction pathway, easy workup and recyclable catalyst without any significant loss in catalytic activity and can be used for large scale synthesis. Hence, the present study describing the synthesis of CoFe2O4@SiO2 nanoparticles by efficient sol-gel auto combustion method followed by the investigation of potent catalytic activities may be useful for nanochemistry research opening a new arena in this field.
Hossein Khoshsang; Ali Ghaffarinejad; Hojjat Kazemi; Sedighe Jabarian
Abstract
The magnetic mesoporous Fe3O4 and Fe3O4/Carbon Nanocomposite (Fe3O4/C) are synthesized by a facile hydrothermal method in one- step and are used for methylene blue dye removal. Nanomaterials are characterized by field-emission scanning electron microscope (FE-SEM), transition electron microscopy ...
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The magnetic mesoporous Fe3O4 and Fe3O4/Carbon Nanocomposite (Fe3O4/C) are synthesized by a facile hydrothermal method in one- step and are used for methylene blue dye removal. Nanomaterials are characterized by field-emission scanning electron microscope (FE-SEM), transition electron microscopy (TEM), energy dispersive X-ray spectrometry (EDX), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and Vibrating sample magnetometry (VSM). The specific surface area of the samples and mean pore diameter were measured via Brunauer–Emmett–Teller (BET) surface area measurement technique. To improve the adsorption performance some important parameters affecting dye removal are optimized. Maximum capacity for methylene blue (MB) adsorption on to Fe3O4 and Fe3O4/C Nanocompositeis 169.5 and 208.33 mg. g-1, respectively, which compared to some same recent reports, has a better adsorption capacity. Thermodynamic parameters (ΔGο, ΔΗο and ΔSο) were calculated and the result showed a spontaneous, endothermic and increase in randomness for dye adsorption. The obtained data has the best fitting with Langmuir isotherm and the kinetic analysis has the best fit by pseudo-second order model.
Eman Serag; Ahmed El Nemr; Azza El-Maghraby
Abstract
A novel Graphene oxide-polyethylene glycol and polyvinyl alcohol (GO-PEG-PVA) triple network hydrogel were prepared to remove Copper(II) ion from its aqueous solution. The structures, morphologies, and properties of graphene oxide (GO), the composite GO-PEG-PVA and PEG-PVA were characterized using FTIR, ...
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A novel Graphene oxide-polyethylene glycol and polyvinyl alcohol (GO-PEG-PVA) triple network hydrogel were prepared to remove Copper(II) ion from its aqueous solution. The structures, morphologies, and properties of graphene oxide (GO), the composite GO-PEG-PVA and PEG-PVA were characterized using FTIR, X-ray diffraction, Scanning Electronic Microscope and Thermal Gravimetric analysis. A series of systematic batch adsorption experiments were conducted to study the adsorption property of GO, GO-PEG-PVA hydrogel and PEG-PVA hydrogel under different conditions (e.g. pH, contact time and Cu2+ ions concentration). The high adsorption capacity, easy regeneration, and effective adsorption–desorption results proved that the prepared GO-PEG-PVA composite hydrogel could be an effective adsorbent in removing Cu2+ ion from its aqueous solution. The maximum adsorption capacities were found to be 917, 900 and 423 mg g–1 for GO-PEG-PVA hydrogel, GO and PEG-PVA hydrogel, respectively at pH 5, 25 °C and Cu2+ ions’ concentration 500 mg l–1. The removal efficiency of the recycled GO-PEG-PVA hydrogel were 83, 81, 80 and 79% for the first four times, which proved efficient reusability.
Ganesh Jethave; Umesh Fegade; Sanjay Attarde; Sopan Ingle
Abstract
The successful synthesis and characterization of AlTiPbO Nanoparticles (ATPO-NPs) using a facile and straight forward co-precipitation method was reported in the present work. The detailed morphological characterization uncovered that the nanoparticles are of 28 nm in size. From the application perspective, ...
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The successful synthesis and characterization of AlTiPbO Nanoparticles (ATPO-NPs) using a facile and straight forward co-precipitation method was reported in the present work. The detailed morphological characterization uncovered that the nanoparticles are of 28 nm in size. From the application perspective, the nanoparticles were utilized as a potential adsorbent to remove the toxic and hazardous dye from the aqueous phase. The point by point adsorption studies uncovered that the AlTiPbO nanoparticles made the Eriochrome black-T solution becomes colorless within 90 min. The outcome of the study verified by isotherms and kinetic study measurements and the adsorption system was examined. The nanoparticles have been effectively reused up to fifth cycle of the adsorption. A real sample analysis study revealed that ATPO-NPs could remove high concentrations (1000 mg/g) of dye from the industrial waste sample.
Syarifah Nazirah Wan Ikhsan; Norhaniza Yusof; Farhana Aziz; Nurasyikin Misdan; Ahmad Fauzi Ismail
Abstract
Halloysite nanotube/ferrihydrite (HNT/HFO) nanocomposites have been synthesized using a simple chemical precipitation method using only one-pot method. The synthesized nanocomposites were characterized for its physicochemical as well as morphological characteristics through X-Ray Diffraction (XRD), Fourier ...
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Halloysite nanotube/ferrihydrite (HNT/HFO) nanocomposites have been synthesized using a simple chemical precipitation method using only one-pot method. The synthesized nanocomposites were characterized for its physicochemical as well as morphological characteristics through X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR) Spectroscopy, Transmission Emission Microscopy (TEM), Energy Dispersive X-Ray Spectroscopy (EDX) as well as Brunauer–Emmett–Teller (BET). The morphology of the synthesized nanocomposites revealed the attachment of HFO to the lining of HNT which confirms its successful grafting on HNT. XRD patterns has revealed the nanocomposite having monoclinic structure in which it agrees with the FTIR results. The high surface area of 328.6 m2/g and high aspect ratio of the HNT-HFO nanocomposites has endowed it with enforcing ability and increased its water absorption capability, which in turn making it highly hydrophilic. The high hydrophilicity and adsorption ability of the nanoparticles has open a wide opportunity for it to be utilized in separation of wastewater.
Lida Rahmanzadeh; Mohsen Ghorbani; Mohsen Jahanshahi
Abstract
Mercury is one of the most toxic metals present in the environment. Adsorption has been proposed among the technologies for mercury adsorbent. The kinetics of adsorption depends on the adsorbent concentration, and the physical and chemical characteristics of adsorbent. In this study we were used a novel ...
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Mercury is one of the most toxic metals present in the environment. Adsorption has been proposed among the technologies for mercury adsorbent. The kinetics of adsorption depends on the adsorbent concentration, and the physical and chemical characteristics of adsorbent. In this study we were used a novel adsorbent, magnetite-polyrhodanine core- shell nanoparticles, for removing Hg(II) from aqueous solution. The effect of pH, initial Hg(II) concentration, initial adsorbent concentration and contact time on the efficiency of Hg(II) removal were investigated systematically by batch experiments. The maximum adsorption capacity was obtained 29.14 mg g-1 at PH=6.5 and 25°C with 10 g L-1 nano adsorbent. The kinetic data of adsorption of Hg(II) ion on the synthesized adsorbent were best described by a pseudo- second- order equation, indicating their chemical adsorption. The Freundlich, Langmuir and Temkin isotherms were used to modeling of mercury adsorption on Hg(II) in aqueous medium which modeled best by the Freundlich isotherm is whole concentration rage.
Ouahiba Bechiri; Mostefa Abbessi
Abstract
The main objective of this work is to study the oxidation of naphthol blue black (NBB) in aqueous solution by hydrogen peroxide using a recyclable Dawson type heteropolyanion [H1.5Fe1.5P2W12Mo6O61.23H2O] as catalyst.The effects of various experimental parameters of the oxidation reaction of the dye were ...
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The main objective of this work is to study the oxidation of naphthol blue black (NBB) in aqueous solution by hydrogen peroxide using a recyclable Dawson type heteropolyanion [H1.5Fe1.5P2W12Mo6O61.23H2O] as catalyst.The effects of various experimental parameters of the oxidation reaction of the dye were investigated. The mineralization of the dye was investigated by the total organic carbon (TOC) measurement in optimum conditions. The influence of the catalyst nature (Dawson- type iron -substituted heteropolyanion) and (Dawson- type copper -substituted heteropolyanion) on the oxidation process was investigated. The catalytic oxidation using a recyclable heteropolyanions as catalysts is an economically and environmentally friendly process to remove the toxicity of the recalcitrant compounds in water.
Vahid Barkhordari; Arezou Jafari
Abstract
This research illustrates the effect of miscibility condition between nanofluid and oil on the process efficiency and to achieve this aim four types of fluid including distilled water, ethanol, n-hexane, and gas condensate were used to disperse silica nanoparticles. The prepared nanofluids were injected ...
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This research illustrates the effect of miscibility condition between nanofluid and oil on the process efficiency and to achieve this aim four types of fluid including distilled water, ethanol, n-hexane, and gas condensate were used to disperse silica nanoparticles. The prepared nanofluids were injected into a glass micromodel and the oil recovery factor and effective mechanisms were investigated. Results showed that in presence of nanoparticles, the oil recovery factor for miscible base fluids injection increases about 30%. But in immiscible base fluids, nanoparticles enhance the oil recovery factor up to 20% more than the base fluids. So nanoparticles are more efficient in miscible base fluids compared to immiscible ones.
Janan Parhizkar; Mohammad Hossein Habibi
Abstract
Photocatalytic treatment of wastewater from azo dyes with semiconductors promises efficient method to refine water. Cobalt ferrite is synthesized and utilized for dye removal as a semiconducting composite. To compare photocatalytic performance of its individual oxides, cobalt oxide and iron oxide were ...
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Photocatalytic treatment of wastewater from azo dyes with semiconductors promises efficient method to refine water. Cobalt ferrite is synthesized and utilized for dye removal as a semiconducting composite. To compare photocatalytic performance of its individual oxides, cobalt oxide and iron oxide were synthesized by the same route and applied to water treatment. In this work, cobalt ferrite, cobalt oxide and iron oxide nanoparticles were synthesized as photocatalysts by employing wet chemical method with chloride precursors respectively (CoCl2.6H2O & FeCl3.6H2O, CoCl2.6H2O, FeCl3. 6H2O). The synthesized photocatalysts were characterized by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), diffuse reflectance spectroscopy (DRS) and field emission scanning electron microscopy (FESEM). The obtained photocatalysts were coated on glass by Dr Blade method. The degradation of Acid Black 1 (AB1) and Reactive Red 4 (RR4) by cobalt ferrite, cobalt oxide and iron oxide was carried out under UV light irradiation to investigate their photocatalytic activities. FeO nanoparticles were found as the best photocatalyst to achieve maximum degradation of Azo dyes. The high degradation performance of FeO can be attributed to photo-Fenton phenomena-like furthermore photocatalytic process. The Degradation rate of AB1 by photocatalysts decreases in the order of FeO > Co3O4> CoFe2O4. The photocatalytic degradation kinetics of AB1 using photocatalyst nanoparticles was found to be the first order kinetic rate. For RR4, CoFe2O4 followed first order, FeO and Co3O4 followed second order kinetic rate. Presence of iron oxide in cobalt ferrite improved the photocatalytic performance.
Sameer Al-Asheh; Ahmed Aidan
Abstract
This work attempted to determine the optimum conditions required for the coagulation and flocculation process as an essential stage of the ceramic wastewater treatment. Coagulation and flocculation is a very necessary step in industries as it lessens turbidity, color, and odor of wastewater. The experimental ...
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This work attempted to determine the optimum conditions required for the coagulation and flocculation process as an essential stage of the ceramic wastewater treatment. Coagulation and flocculation is a very necessary step in industries as it lessens turbidity, color, and odor of wastewater. The experimental work was performed in several runs. The volume of wastewater used in each run was 200 mL and was kept at this value throughout. In certain runs, the speed of the mixer was varied while keeping the quantity of coagulant and flocculant constant in order to determine the optimum speed that resulted in the least turbidity. A speed of 5% was chosen as the ideal process speed according to the results obtained. Next, experiments were operated at this optimum speed while changing the dosage of coagulant and flocculant in order to decide the optimum dosage. Coagulant and flocculent amounts of 0.4 g (without booster) and 0.2 g (with booster) selected after the readings were taken. For all the readings, a turbidity meter was used providing results in Nephelometric Turbidity Units (NTU). Lowest turbidity was achieved when using 5% speed with 0.4 grams of coagulant and 0.4 grams of flocculant, or 5% speed with 0.2 grams of coagulant, 0.2 grams of flocculant and 0.25 g/L of booster coagulant. According to factorial design analysis, such as parameters as impeller speed and dosage have an influential impact on the turbidity; while the booster has insignificant influence and other interactions between parameters are important.
Masoumeh Tajmiri; Mohammad Reza Ehsani
Abstract
Water is critically important, because its supply is under stress. In oil fields, the ratio-of-water-to-oil (WCUT%) can be 95% or higher. Managing this produced water is a great challenge whereas the best opportunity to reduce costs, improve profitability and preserve the natural environment. The oil ...
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Water is critically important, because its supply is under stress. In oil fields, the ratio-of-water-to-oil (WCUT%) can be 95% or higher. Managing this produced water is a great challenge whereas the best opportunity to reduce costs, improve profitability and preserve the natural environment. The oil industry is looking for more effective ways to reduce water consuming and improve the recovery rates. Nano materials are an obvious place to look. This study provides new insights into ZnO nanoparticles effects on residual oil saturation (SOR) and WCUT% through steam assisted gravity drainage (SAGD) process by experimental work. Laboratory tests were conducted in two experiments through the use of 2 dimensional scaled SAGD cell from an Iranian heavy oil reservoir. In the first experiment, the SAGD cell was saturated with heavy oil and in the second one, the cell was flooded with nanoparticles before saturation with oil. The amount of recoveries were monitored during 12 hours. Results show that the ultimate oil recoveries increase from 52.43% to 87.93% by adding ZnO nanoparticles, respectively. The experimental results provide the nanoparticles ability to reduce produced water and minimize fresh water use can contribute to water conservation.
Alireza Nouri; Ramin Yavari; Mohammad Ali Aroon; Taher Yousefi
Abstract
In the present research work, the mixed matrix membranes (MMMs) containing various amount of polyethersulfone (PES) and functionalized multi-walled carbon nanotubes (fMWCNTs) were fabricated and used to investigate the removal of cobalt ions from wastewater by nanofiltration process. Pristine MWCNTs ...
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In the present research work, the mixed matrix membranes (MMMs) containing various amount of polyethersulfone (PES) and functionalized multi-walled carbon nanotubes (fMWCNTs) were fabricated and used to investigate the removal of cobalt ions from wastewater by nanofiltration process. Pristine MWCNTs and fMWCNTs were characterized by Fourier transformed infrared spectroscopy and thermogravimetric analysis. FESEM analysis revealed that the mixed matrix membranes have less surface defects and better membrane performance compared with neat polymeric in the removal of cobalt ions. Permeation test results showed that the MMM containing 22 wt. % PES and 0.6 wt. % fMWCNTs (with outer diameter of 10-20 nm) has the optimum performance from the permeability and cobalt removal point of view. In continuation, the effect of pressure, feed flow rate, cobalt concentration, permeation test time and feed solution pH on the removal of cobalt by selected the MMM was investigated. The obtained results indicated that only pressure has considerable effect on permeation flux. However, all parameters showed different influence on rejection percent of cobalt ions.
Shirish Sadashiv Pingale; Shobha Vasant Rupanar; Manohar Chaskar
Abstract
The present study reports one step green synthesis of silver nanoparticles using Gymnema sylvestre aqueous extract at room temperature and their usage in the photodegradation of methyl orange dye. The silver nanoparticles are synthesized using an aqueous extract of stem and root of Gymnema sylvestre. ...
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The present study reports one step green synthesis of silver nanoparticles using Gymnema sylvestre aqueous extract at room temperature and their usage in the photodegradation of methyl orange dye. The silver nanoparticles are synthesized using an aqueous extract of stem and root of Gymnema sylvestre. UV-Visible spectral analysis showed absorbance peak at 430 nm with special reference to the excitation of surfaces plasmon vibration by silver nanoparticles. FT-IR analysis of nanoparticles reveals the presence of molecular functional groups such as amides, phenolic compounds, and carboxylic acid. These phytochemicals act capping and stabilizing agents for silver nanoparticles. EDAX elemental analysis shows the presence of silver as the main element in synthesized nanoparticles. The average crystalline size of silver nanoparticles was found to be 25.3 nm and 9.97 nm for Stem-AgNPs and Root-AgNPs respectively by Scherer formula. XRD patterns also suggest the occurrence of crystalline silver ions. Further, photocatalytic degradation of methyl orange was measured spectrophotometrically by using silver nanoparticles as nanocatalyst under solar light effect. The results revealed that biosynthesized silver nanoparticles using G. sylvestyre was found to be notable in degrading methyl orange dye under the influence of sunlight.
Hanieh Karimnezhad
Abstract
The fabrication of functionalized membranes with hydrophobic/oleophilic surfaces for the elimination of n-hexane from water using para-aminobenzoate alumoxane, boehmite-epoxide and a novel nanoparticle, i.e., Stearate Alumoxane by a simple coating technique, is reported here. FTIR was used to characterize ...
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The fabrication of functionalized membranes with hydrophobic/oleophilic surfaces for the elimination of n-hexane from water using para-aminobenzoate alumoxane, boehmite-epoxide and a novel nanoparticle, i.e., Stearate Alumoxane by a simple coating technique, is reported here. FTIR was used to characterize nanoparticles. SEM and contact angle measurement analyses were used to identify the nanocomposite membranes. The concentrations of oil in permeate and retentate were measured by UV/vis spectrophotometer. The morphology of Stearate alumoxane nanoparticles was investigated by means of SEM images. The composed film of nanoparticles on the Kevlar fabric was hydrophobic with water contact angle of ~ 145° and oleophilic with oil contact angle of ~ 0º. In addition, the membranes retained stable hydrophobicity and high separation efficiency even after employing for 6 times. Applying these properties, a setup was considered using the functionalized Kevlar fabric to separate oil through down to a collector and leave water drops. Our batch filtration system was exclusively gravity-driven. The achieved separation system can separate the oily water mixture (with the concentration of 20 % (v/v) n-hexane in water), effectively with a separation efficiency of 84%.
Malak Ali El Tfayli; Fatima Ali Makki; Mounir Mustapha Kassir; Mouhiaddine Mohamed El Jamal; Azadeh Ebrahimian Pirbazari
Abstract
In this work, we studied the effect of various amounts (0.2-1.2 % mole ratio) of Cu doping to TiO2 nanoparticles (Cu/TiO2) on the photocatalytic removal efficiency of the food colorant E 131 VF. Two series of doped TiO2 (P25) photocatalysts were prepared in two different media (50%ethanol-50%acetone ...
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In this work, we studied the effect of various amounts (0.2-1.2 % mole ratio) of Cu doping to TiO2 nanoparticles (Cu/TiO2) on the photocatalytic removal efficiency of the food colorant E 131 VF. Two series of doped TiO2 (P25) photocatalysts were prepared in two different media (50%ethanol-50%acetone and 5% surfactant (Tween 20)-95%H2O) by using the impregnation method. The prepared samples were characterized by XRD, FTIR, Raman, diffuse reflectance spectroscopy and SEM/EDX analyses. The XRD results showed that the crystal dimension of TiO2 increased from 23 to 35 nm and rutile/anatase ratio decreased from 16% to 9% after Cu doping in two different media. The photoactivity of TiO2 was reduced in the presence of Cu even at low molar ratio. The photocatalytic degradation rate constant of TiO2 (P25) was 0.24 (au) but it decreased to 0.015 (au) in the presence of the sample containing 0.6% Cu. Several reasons were suggested to explain the dramatic decrease in the activity of the prepared Cu/TiO2samples.
Abdolreza Kazemi Abadshapoori; Yousef Kazemzadeh; Mohammad Sharifi; Masoud Riazi
Abstract
Oil production from oil reservoirs containing oil in water (O/W) and water in oil (W/O) emulsions has always been accompanied by some problems. The increase in apparent viscosity of the oil, pore throats blockage, and consequently, the increased rate of pressure drop are among these problems. Investigating ...
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Oil production from oil reservoirs containing oil in water (O/W) and water in oil (W/O) emulsions has always been accompanied by some problems. The increase in apparent viscosity of the oil, pore throats blockage, and consequently, the increased rate of pressure drop are among these problems. Investigating the behavior of this type of oil in the porous medium can help to understand the problem. Although metal oxide nanoparticles can increase the oil recovery and therefore improve the performance of reservoirs, they can result in the formation of W/O emulsions, due to their potential properties. In this study, the formation and stability of the emulsion were first evaluated and then the nanofluids were injected into a carbonate sand pack. Tests were conducted in the ambient condition. The amount of produced oil in the presence of three nanoparticles consist of TiO2, SiO2, and Fe3O4 has been investigated. Moreover, the effect of water injection on the system containing emulsions created by both different ions present in the seawater and iron oxide nanoparticles has been investigated. The results show that the iron oxide nanoparticles cause high-pressure oscillations by forming more stable emulsions in the porous media.