Mohammad Hadi Yousefi; Mohamad Mehdi Zerafat; Majid Shokri Doodeji; Samad Sabbaghi
Abstract
The objective of this work is to investigate the effect of dip-coating parameters on the performance of Alumina-PDMS hybrid nanofiltration membranes for water desalination. Ceramic supports used in this work were prepared with a 340 nm average pore size and 34% total porosity. The aim is to determine ...
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The objective of this work is to investigate the effect of dip-coating parameters on the performance of Alumina-PDMS hybrid nanofiltration membranes for water desalination. Ceramic supports used in this work were prepared with a 340 nm average pore size and 34% total porosity. The aim is to determine optimum conditions of dipping time, PDMS concentration, and withdrawal speed in order to achieve high rejection and flux values. Dip-coating parameters were considered as dipping time (60 - 120 s), withdrawal speed (5 - 15 mm/s) and PDMS concentration (10 - 20 wt. %). Hybrid membranes were characterized using FE-SEM and FTIR analysis techniques. Pure water flux and salt rejection were also measured to evaluate the rejection performance. Alumina-PDMS hybrid nanofiltration membranes fabricated with dipping time = 120 s, withdrawal speed = 15 mm/s and 10 wt. % PDMS exhibited the best performance giving 30.5% rejection for NaCl and 53.8% for Na2SO4.
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.
Bhavani Nenavathu; Aarti Sharma; Raj Kumar Dutta
Abstract
Pristine and Se doped ZnO nanoparticles (NPs) were successfully synthesized by thermo-mechanical method and their structural, morphological and optical properties are characterized. Here in, a series of experiments were carried out where cholesterol is treated with same concentration of Pristine as well ...
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Pristine and Se doped ZnO nanoparticles (NPs) were successfully synthesized by thermo-mechanical method and their structural, morphological and optical properties are characterized. Here in, a series of experiments were carried out where cholesterol is treated with same concentration of Pristine as well as Se doped ZnO NPs. Several Cholesterol oxidation products (COP’s) such as 25-hydroxycholesterol and 26-hydroxycholesterol, 7α-hydroxycholesterol, 7β-hydroxycholesterol, 7-ketocholesterol are formed as observed by HPLC analysis. The batch of 5 wt % Se doped ZnO NPs exhibited highest cholesterol degradation efficiency followed by pristine ZnO NPs and 2 wt % Se doped ZnO NPs. The peak area corresponding to 7-ketocholesterol and 25-hydroxycholesterol is found to be 200980 AU and 200986 AU respectively. The mechanism of cholesterol degradation was correlated with incorporation of oxygen vacancies due to Se doping, which were likely intermediate levels for transiting photoexcited charge carriers for generation of hydroxyl radicals. Further, hydroxyl radicals generated during interaction of ZnO nanoparticles with aqueous media have been determined using terephthallic acid assay and 2′, 7′-di-chlorofluorescein (DCF) assay.
Soodabeh Khalili; Ali Asghar Ghoreyshi; Mohsen Jahanshahi; Behnam khoshandam
Abstract
Multiwalled carbon nanotubes (MWCNT) were found to be an effective separation media for purifing CO2 from O2. Significant uptakes of CO2 and O2 were measured at 288 K, 298K and 308 K over the pressure range of 1 to 40 bar using volumetric method in dual sorption vessels. The same shape of isotherms ...
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Multiwalled carbon nanotubes (MWCNT) were found to be an effective separation media for purifing CO2 from O2. Significant uptakes of CO2 and O2 were measured at 288 K, 298K and 308 K over the pressure range of 1 to 40 bar using volumetric method in dual sorption vessels. The same shape of isotherms introduced a common mechanism of adsorption but the amount of CO2 adsorbed on MWCNT is 2 times higher than O2 adsorption. The mass uptake of CO2 and O2 by MWCNT was found to increase with increasing pressure and decreasing temperature. The experimental data was well fitted by the Langmuir and Freundlich model isotherms considering the values of regression correlation coefficients. Following a simple acidic treatment procedure, CO2 and O2 adsorption was increased over range of pressure. The adsorbents was characterized by N2 adsorption isotherm at 77 K, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). The effect of temperature and pressure on selectivity obtained from IAST demonstrated that maximum selectivity over the pressure and temperature ranges p = 0.5-5 bar and T = 298–308 K was achieved at 308 K and 5 bar.
Ines Bouaziz; Morched Hamza; Ridha Abdelhedi; André Savall; Karine Groenen Serrano
Abstract
The electrochemical regeneration of methylene blue-saturated activated carbon, Nyex®1000 and sawdust has been studied and the performances in terms of capacity of adsorbent regeneration have been compared in this work. The adsorption isotherms were investigated. The results showed that the adsorption ...
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The electrochemical regeneration of methylene blue-saturated activated carbon, Nyex®1000 and sawdust has been studied and the performances in terms of capacity of adsorbent regeneration have been compared in this work. The adsorption isotherms were investigated. The results showed that the adsorption of methylene blue onto the investigated adsorbents obeyed Langmuir’s model. The electrochemical oxidation of methylene blue beforehand adsorbed was studied using a boron doped diamond anode. The electrochemical regeneration efficiencies, under the same experimental conditions, of the activated carbon and Nyex®1000 were significantly less than 100% which were much lower to that of sawdust. Indeed the electrolysis tends to activate the sawdust because all the regeneration efficiencies obtained, whatever the applied current intensity, are higher than 100 %. Increasing treatment time would also result in a better regeneration of sawdust. This study confirmed that the coupling adsorption onto sawdust and electrochemical degradation is a potential technique for the efficient elimination of low concentration organic dyes from wastewater.
Faride Behboudi; Zeinolabedin Tahmasebi Sarvestani; Mohamad Zaman Kassaee; Seyed Ali Mohamad Modares Sanavi; Ali Sorooshzadeh; Seyed Badreddin Ahmadi
Abstract
As a step towards the profitable employment of nanoparticles (NPs) in agriculture, effects of chitosan NPs was probed on barley plants under late season drought stress. A factorial experiment was performed based on a randomized complete block design with three replications. The experimental factors included ...
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As a step towards the profitable employment of nanoparticles (NPs) in agriculture, effects of chitosan NPs was probed on barley plants under late season drought stress. A factorial experiment was performed based on a randomized complete block design with three replications. The experimental factors included the chitosan NPs concentrations (0 (control), 30, 60 and 90 ppm), application methods (foliar and soil application) and irrigation regimes (well-watered and withholding of irrigation for 15 days after pollination). The barley seeds were separately planted in pots. Then, the NPs were added to them through the soil and foliar application at three stages. The results indicated that using the chitosan NPs, especially 60 and 90 ppm, significantly increased the leaf area (LA), the leaf color (SPAD), the number of grain per spike, the grain yield and the harvest index compared to the control. Also, drought stress significantly decreased the yield and yield components compared to the well-watered plants. In contrast, using the chitosan NPs in plants under drought stress significantly increased the relative water content (RWC), the 1000-grain weight, the grain protein, the proline content, the catalase (CAT) and the superoxide dismutase (SOD) compared to the control. There was no a significant difference between two methods of using NPs in most studied traits. The results highlighted that using the chitosan NPs, especially 60 and 90 ppm, in both irrigation regimes can significantly improve the majority of the studied traits compared to the control and mitigate the harmful effects of drought stress.
Farnosh Tavakoli; Alireza Badiei; Jahan Bakhsh Ghasemi
Abstract
In this paper, Ag-TiO2-Graphene (Ag-TiO2-G) photocatalyst is synthesized via an economic and green rout. Pranus Cerasus is applied as a green reducing agent due to the presence of anthocyanin pigment. The anthocyanin molecules are responsible for the red color of the prunus cerasus seeds. The nanocmposites ...
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In this paper, Ag-TiO2-Graphene (Ag-TiO2-G) photocatalyst is synthesized via an economic and green rout. Pranus Cerasus is applied as a green reducing agent due to the presence of anthocyanin pigment. The anthocyanin molecules are responsible for the red color of the prunus cerasus seeds. The nanocmposites were characterized by XRD, EDS mapping, DRS and TEM. In order to explore the presence of Ag, different mass ratio of Ag to in Ag-TiO2-G composite (5wt%, 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt%, 40wt%, 45wt% and 50wt%) were synthesized and their performance on the Acid Orange 7 (AO7) photodegradation were compared with bare graphene. In addition, for investigation of the presence of graphene, the Ag-TiO2 was synthesized and compared with the Ag-TiO2-G composite from the photocatalytic performance point of view. Ag nanoparticles and graphene are two crucial factors in AO7 photodegradation. Finally, we showed that photodegradation of AO7 with photocatalyst depends on photogenerated holes.
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.
Smitha Vijayan; Divya Koilaparambil; Tijith K George; Jisha Manakulam Shaikmoideen
Abstract
The present study establish extracellular production of silver nanoparticles (AgNP) using Fusarium solani, from medicinal plant Withania somnifera (L.) (ashwagandha) and it’s antibacterial and cytotoxicity effects. Biological- AgNP (Bio- AgNP) were synthesized by using fungal cell free extract ...
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The present study establish extracellular production of silver nanoparticles (AgNP) using Fusarium solani, from medicinal plant Withania somnifera (L.) (ashwagandha) and it’s antibacterial and cytotoxicity effects. Biological- AgNP (Bio- AgNP) were synthesized by using fungal cell free extract and characterized by SEM, TEM, UV spectroscopy, XRD, FTIR and AFM analysis. Antibacterial properties were assayed by well diffusion and cytotoxicity by RBC lysis test and MTT assay respectively. X- ray diffraction and microscopic analysis revealed the well dispersed and crystalline nature of spherical nanoparticles with a calculated size ranging from 10 - 50 nm. The Bio-AgNP exhibited significant antibacterial properties in a range of 50-100 µgml-1 against the selected clinical pathogens Escherichia coli,Pseudomonas aeruginosa, Salmonella typhi, Staphylococcus aureus and Klebsiella pneumoniae. The observed hemolysis of 3.906 % at 50 µg ml-1 suggested the safe therapeutic application of Bio - AgNP. MTT assay revealed that at the suggeseted concentration 69 % of cells are viable. These outcomes are extremely encouraging to utilize Bio-AgNP as a medication. Exploiting the endophytic organisms from therapeutic plants for improvement of nanomaterial is a uninvestigated and relatively novel territory. This may improve the likelihood in future to push the limit ahead in nanomedicine.
Narasimha Raghavendra; Anjali S. Bhinge; Pooja J Ganiger
Abstract
The corrosion inhibition effect of Areca root extract on the mild steel (MS) surface in the 3 M HCl solution was examined by gasometric, colorimetric, Tafel plot, impedance and atomic absorption spectroscopy techniques. Gasometric studies show that, the extract behaves as green corrosion inhibitor in ...
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The corrosion inhibition effect of Areca root extract on the mild steel (MS) surface in the 3 M HCl solution was examined by gasometric, colorimetric, Tafel plot, impedance and atomic absorption spectroscopy techniques. Gasometric studies show that, the extract behaves as green corrosion inhibitor in the 3 M HCl system on the MS surface. The protection rate enhances with a rise in the plant extract concentration. Colorimetry studies show that, minimum weight loss observed at 0.4 g/L of plant extract. The minimum weight loss of MS in the 3 M HCl solution is an indication of protection property of Areca root extract. Atomic absorption spectroscopy technique shows that, increase in the amount of Areca root extract increases the protection inhibition property. Mixed corrosion inhibition property of Areca root extract was confirmed from the potentiodynamic polarization technique. Trend of charge transfer resistance values with different amounts of plant extract also supports the corrosion inhibition property of Areca root extract. SEM studies fully support the gasometric, colorimetric, Tafel plot, impedance and atomic absorption spectroscopy techniques.
Elsayed Talat Helmy; Ahmed El Nemr; Mahmoud Mousa; Esam Arafa; Shady Eldafrawy
Abstract
This paper describes the photocatalytic degradation of Reactive Blue 19 (RB-19) and Reactive Red 76 (RR-76) dyes pollutant in the industrial wastewater using TiO2, C-doped TiO2(C-TiO2), S-doped TiO2 (S-TiO2) and C,S co-doped TiO2 (C,S-TiO2)nanoparticles as photocatalysts, which were synthesized via sol-gel ...
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This paper describes the photocatalytic degradation of Reactive Blue 19 (RB-19) and Reactive Red 76 (RR-76) dyes pollutant in the industrial wastewater using TiO2, C-doped TiO2(C-TiO2), S-doped TiO2 (S-TiO2) and C,S co-doped TiO2 (C,S-TiO2)nanoparticles as photocatalysts, which were synthesized via sol-gel process. The prepared photocatalysts were characterized by scanning electron microscopy (SEM), X-Ray diffraction (XRD), Fourier transformer infra-red spectroscopy (FTIR), Energy dispersive spectroscopy (EDAX) and ultraviolet-visible absorption spectroscopy (UV-Vis). The dyes degradation was investigated under several experimental parameters such as pH, catalyst load, dye concentration, shaking speed, irradiation time and catalyst recovery. The photocatalytic dose was found to be 1.6 g/L and the efficiency of RB-19 and RR-76 photocatalytic degradation attained 100 % after 1 h irradiation time under visible light. The chemical oxygen demand (COD) values were determined for wastewater and treated wastewater. Toxicity and biological activity of the treated and untreated wastewater on marine aquatic organisms rotifer, artemia and Vibrio parahaemolyticus were investigated.
Hidouri Khaoula; Benhmidene Ali; Chaouachi Bechir; Ravishankar Sathyamurthy
Abstract
In isolated and arid areas, especially in the almost Maghreb regions, the abundant solar radiation intensity along the year and the available brackish water resources are the two favorable conditions for using solar desalination technology to produce fresh water. The present study is based on the use ...
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In isolated and arid areas, especially in the almost Maghreb regions, the abundant solar radiation intensity along the year and the available brackish water resources are the two favorable conditions for using solar desalination technology to produce fresh water. The present study is based on the use of three groups of correlation, for evaluating mass transfer. Theoretical results are compared with those obtained experimentally for a Simple Solar Distiller (SSD) and a Simple Solar Distiller Hybrid with a Heat Pump (SSDHP) stills. Experimental results and those calculated by Lewis number correlation show good agreements. Results obtained by Dunkle, Kumar and Tiwari correlations are not satisfactory with the experimental ones. Theoretical results, as well as statistical analysis, are presented. The model with heat pump ( for two configurations (111) and (001) give more output compared with the model without heat pump ((000) and (110)). This results where agree for the use of the statistic results, the error it less with Lewis number as compared with the different correlation.
Ahmad Vakili Tajareh; Hossein Ganjidoust; Bita Ayati
Abstract
In this study, TiO2/Fe3O4 and TiO2/Fe3O4/MWCNT as a new magnetic nanophotocatalytic materials were synthesized. For this, TiO2 nanoparticle were fixed on an inert surface by sonochemical method. X-ray Diffraction (XRD), scanning electron microscopy (SEM), UV-Vis diffuse reflectance spectroscopy (DRS), ...
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In this study, TiO2/Fe3O4 and TiO2/Fe3O4/MWCNT as a new magnetic nanophotocatalytic materials were synthesized. For this, TiO2 nanoparticle were fixed on an inert surface by sonochemical method. X-ray Diffraction (XRD), scanning electron microscopy (SEM), UV-Vis diffuse reflectance spectroscopy (DRS), vibration sample magnetometry (VSM) were used to characterize the magnetic nanocomposites. SEM analysis indicated that TiO2 and Fe3O4 nanoparticles were adhered to MWCNT. Ability of the nanocomposites to remove organic pollutants were investigated by photodegradation of Acid Red 14, Acid Blue 19, Reactive Red 77, and Methyl Orange dyes simulated conditions similar to sunlight. Furthermore, the removal efficiency of AR14 were investigated under direct sunlight irradiation, with an initial concentration of 50 mg/L by TiO2, TiO2/Fe3O4 and TiO2/Fe3O4/MWCNT nanocatalysts were 89.83, 21.19 and 86.27, respectively. According to the results, addition of carbon nanotubes to the TiO2/Fe3O4 magnetic nanocomposite, increased the efficiency of AR14 photodegradtion through change in energy gap visible waves and the scavenging role of carbon nanotubes. Also, The reusability of nanocomposites was assessed in five consecutive cycles of 6 hours, The results showed that after 5 cycles the degradation rate decreased only 7.79 %.
Nima Gholami; Ahmad Dadvand Koohi; Azadeh Ebrahimian Pirbazari
Abstract
The methylene blue (MB) adsorption from aqueous solution was investigated through Fe3O4 nanoparticles loaded on Fish Scale (FS) from fishery biomass. The presence of collagen fibers, apatite crystals and nano-magnetite particles in the structure of nano-magnetic fish scale (MFS) was observed in ...
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The methylene blue (MB) adsorption from aqueous solution was investigated through Fe3O4 nanoparticles loaded on Fish Scale (FS) from fishery biomass. The presence of collagen fibers, apatite crystals and nano-magnetite particles in the structure of nano-magnetic fish scale (MFS) was observed in FTIR, EMA and XRD results. From nitrogen physisorption studies, the FS and MFS specific surface areas were estimated at 0.65 and 4.86 m2/g, respectively. The negative values of ∆G0 and ∆H0 confirmed that the adsorption was a spontaneous and exothermic process, respectively. The MB adsorption onto MFS was a physisorption controlled process. The Sips equation estimated the best fit to the data compared with other isotherm equations. The Langmuir and Sips maximum adsorption capacities (Qmax) were 68.72 and 60.87 mg/g, respectively. MB removal by MFS followed the model of pseudo-second order rate kinetics. The reusability potential of the MFS was studied, and results showed an efficiency of 59.63%.
Shahryar Jafarinejad
Abstract
Large quantities of oily wastewaters can be generated from the activities and processes in the petroleum industry which draining of these effluents not only pollutes the environment but also reduces the yield of oil and water. Therefore, development of treatment processes for petroleum industry wastewaters ...
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Large quantities of oily wastewaters can be generated from the activities and processes in the petroleum industry which draining of these effluents not only pollutes the environment but also reduces the yield of oil and water. Therefore, development of treatment processes for petroleum industry wastewaters is vital in order to prevent serious environmental damage and provide a source of water for beneficial use. Reverse osmosis (RO) can be the most common membrane process used for desalination from oily wastewater and can produce water suitable for reuse at the petroleum industry. In this study, the application of RO technology for the petroleum industry wastewater treatment in different laboratory, pilot, field, and industrial scales have been reviewed. In addition, membrane fouling control, performance efficiency, treatment system configurations, pretreatment methods, quality of treated water, and economic issues have been investigated. With mixtures as complex as petroleum industry wastewaters, membrane fouling becomes a significant hurdle to implement the RO-based purification system. Operating the system within the critical flux range or adding chemicals, and/or pretreatment can usually control membrane fouling. Salt rejection of RO membranes can be 99% or higher.
Soodabeh Khalili; Mohsen Jahanshahi
Abstract
The objective of this work is to develop a cost-effective carbonaceous CO2 adsorbent. N-doped porous carbon (NDC) with nano- pore size was synthesized by KOH activation of nano polyaniline (PANI). PANI synthesized in this work has thin nanofibrillar morphology with different lengths and diameters. The ...
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The objective of this work is to develop a cost-effective carbonaceous CO2 adsorbent. N-doped porous carbon (NDC) with nano- pore size was synthesized by KOH activation of nano polyaniline (PANI). PANI synthesized in this work has thin nanofibrillar morphology with different lengths and diameters. The activation process was carried out at 800 °C with KOH/precursor ratio of 2. This adsorbent of carbon exhibits high CO2 adsorption capacity of 1.9 mmol/g at 25 °C under atmospheric pressure. The morphology of PNCs is investigated through different technical methods, such as scanning electron microscopy (SEM), N2 adsorption isotherm at 77 K and Fourier transform infrared spectroscopy (FTIR). The CO2 adsorption experiments were done at three different temperatures (298, 308, and 318 K) and pressures up to 10 bar, and correlated with the Langmuir, Freundlich, and Sips models. The Sips isotherm model presented the best fit to the experimental data. Small values of isosteric heat of adsorption were evaluated based on Clausius–Clapeyron equation showed the physical nature of adsorption mechanism. The high amount of CO2 capture by nano- pore size NDC renders it as a promising carrier for practical applications such as gas separation.
Mehdi Sedighi; Majid Mohammadi
Abstract
Consistent with the US Environmental Protection Agency, heavy metals are classified as carcinogenic to humans. Their numerous agricultural, industrial, domestic, medical, and technical requirements have resulted in their widespread dissemination in the environment. This article examines a new green adsorbent ...
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Consistent with the US Environmental Protection Agency, heavy metals are classified as carcinogenic to humans. Their numerous agricultural, industrial, domestic, medical, and technical requirements have resulted in their widespread dissemination in the environment. This article examines a new green adsorbent for the removal of two hazardous heavy metals, lead and mercury. The impact of contact time, pH, initial concentration, and temperature on the adsorption capacity of Pb2+ and Hg2+ were evaluated. Experimental data were analyzed by adsorption models. The equilibrium data were well adapted to the Langmuir adsorption model. The results show that the adsorption is homogeneous and localized in a monolayer. In addition, the maximum adsorption capacity was 277.78 mg/g for Pb2+ and 64.52 mg/g for Hg2+ from Langmuir isotherm. Thermodynamic data, including free energy (ΔG°), enthalpy (ΔH°), and entropy (ΔS°) variations were also considered. The important point is that the negative value of ΔG° signifies the spontaneity of the adsorption process of the heavy metals−NiO/ZSM-5 system.
Tooraj Beyki; Mohammad Javad Asadollahzadeh
Abstract
For the first time, uniform molecularly imprinted polymer (MIP) nanoparticles were prepared using dicamba as a template. The MIP nanoparticles were successfully synthesized by precipitation polymerization using methacrylic acid (MAA) as functional monomer, trimethylolpropane trimethacrylate (TRIM) as ...
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For the first time, uniform molecularly imprinted polymer (MIP) nanoparticles were prepared using dicamba as a template. The MIP nanoparticles were successfully synthesized by precipitation polymerization using methacrylic acid (MAA) as functional monomer, trimethylolpropane trimethacrylate (TRIM) as cross-linker and acetonitrile as porogen. The produced polymers were characterized by differential scanning calorimetry (DSC) and their morphology was precisely examined by scanning electron microscopy (SEM). The MIP nanospheres were obtained with the average diameter of 234 nm. Batch-wise guest binding experiments were carried out to determine the removal efficiency of the produced MIP nanoparticles towards the template molecule in aqueous solutions. The MIP showed outstanding affinity toward dicamba in aqueous solution with maximum removal efficiency of 87.5% at 300 mg.L-1 of dicamba solution. The MIP exhibited higher adsorption efficiency compared with the corresponding non-imprinted polymer (NIP) as well as outstanding selectivity towards dicamba relative to the template analog in an aqueous solution. Moreover, effects of pH on removal efficiency and selectivity of MIP were evaluated in detail.
Jafar Azamat
Abstract
Molecular dynamics simulations were carried out to study the removal of Ni2+ as a heavy metal from the water by the functionalized graphene nanosheet (GNS) and boron nitride nanosheet (BNNS). Nickel causes asthma, conjunctivitis and inflammatory reactions and nickel salts act as emetics when swallowed; ...
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Molecular dynamics simulations were carried out to study the removal of Ni2+ as a heavy metal from the water by the functionalized graphene nanosheet (GNS) and boron nitride nanosheet (BNNS). Nickel causes asthma, conjunctivitis and inflammatory reactions and nickel salts act as emetics when swallowed; therefore, removal of nickel is necessary from the aqueous solutions. The systems were comprised of a nanosheet (GNS or BNNS) with a pore in its center that it is containing an aqueous ionic solution of nickel chloride. For the removal of Ni2+ from an aqueous solution, the pores of nanosheet were functionalized by passivating each atom at the pores edge and then an external electric field was applied along the z-axis of the simulated system. To justify the passage of ions through the pores, the potential of the mean force (PMF) of ions was calculated. To evaluate the properties of the system, the ion retention time and the radial distribution functions of species were measured. Based on the findings of this study, these nanostructure membranes can be recommended as a model for removal of heavy metals.
Reza Tayebee; vahid Mazruy
Abstract
The limited adsorption capacity of natural clays is a crucial and economic issue which confined their applications in industry as cheap adsorbents to remove toxic contaminants from wastewaters. Here, the adsorption capacity of a natural nano bentonite was enhanced by a simple acid and thermal activation ...
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The limited adsorption capacity of natural clays is a crucial and economic issue which confined their applications in industry as cheap adsorbents to remove toxic contaminants from wastewaters. Here, the adsorption capacity of a natural nano bentonite was enhanced by a simple acid and thermal activation and the manufactured nano-adsorbent was characterized by FESEM, BET, FT-IR, and XRD. Effects of pH, temperature, sorbent capacity, and the initial concentration of malachite green were examined. The isotherm behavior of the adsorption system was investigated by the Langmuir and Freundlich isotherm models. Also, the kinetic inspections demonstrated that the adsorption of malachite green matched with the pseudo-second-order kinetic and the obtained thermodynamic parameters H, S, and G showed that the adsorption of malachite green was a spontaneous and endothermic process. The results indicated that the acid-thermal activated nano bentonite, with an enhanced surface area of >220 m2/g, can be depleted as a powerful and low-cost adsorbent to expel malachite green from aqueous solutions.
siroos shojaei; Jamal Ahmadi; Meysam Davoodabadi Farahani; Bentolhoda Mehdizadehd; Mohammadreza Pirkamali
Abstract
The remaining dye in the wastewater is not desirable as it damages the ecosystem and nature, and also is very toxic. The Crystal Violet (CV) dye is toxic and potentially carcinogenic. In addition, it reduces light in water and prevents the process of photosynthesis of aquatic plants. Therefore, nanozeolite-X ...
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The remaining dye in the wastewater is not desirable as it damages the ecosystem and nature, and also is very toxic. The Crystal Violet (CV) dye is toxic and potentially carcinogenic. In addition, it reduces light in water and prevents the process of photosynthesis of aquatic plants. Therefore, nanozeolite-X (NX) was utilized as an adsorbent to remove the CV; effects of pH, catalyst mass, sonication time, and concentration of dye were also investigated. Effects of variables on the removal efficiency were studied via the Central Composite Design (CCD) to determine the dye removal percentage. The quadratic model was selected to predict the removal efficiency using the software. Optimal conditions for CV removal from aqueous solution were: pH= 8, sonication time= 6 min, concentration of dye= 13 mg L-1, and catalyst mass= 0.26 g. In these circumstances, the recovery efficiency was 97.60%. The research results indicated that NX could be applied potentially for CV removal.
Soheill Azadikhah Marian; Morteza Asghari; Zahra Amini
Abstract
In this work, performance of composite membranes was investigated for desalination of Kashan city’s water via pervaporation process. PEBA/PAN/PE, PEBA/PSF/PE and PEBA+NaX/PSF/PE composite membranes that used, was synthesized via a phase inversion route. For all experiments under 45◦C, salt rejection ...
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In this work, performance of composite membranes was investigated for desalination of Kashan city’s water via pervaporation process. PEBA/PAN/PE, PEBA/PSF/PE and PEBA+NaX/PSF/PE composite membranes that used, was synthesized via a phase inversion route. For all experiments under 45◦C, salt rejection was too high and equals to 99.9% that this quantity dropped by increasing the temperature that cause membrane swelling in high temperatures. Water contact angle and water take-up were measured to evaluate the hydrophilicity of the membrane. Also the effect of operating conditions including feed temperature and permeate pressure on permeability and selectivity is discussed. A permeate flux of 4.93 kg/m2h with salt rejection of 99.9% could be achieved at a feed temperature of 50 °C and a vacuum of 0.04 bar. Apparent diffusion coefficients of water at various permeate pressure and feed temperature are calculated. The most effective parameter was feed temperature.
Sedigheh Zeinali; Maryam Abdollahi; Samad Sabbaghi
Abstract
The β-cyclodextrin coated magnetic nanoparticles were prepared by the surface modification of Fe3O4 magnetic nanoparticles using carboxymethyl-β-cyclodextrin. Prepared nanoparticles were characterized by X-ray diffraction analysis, transmission electron microscope, Fourier transform infrared ...
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The β-cyclodextrin coated magnetic nanoparticles were prepared by the surface modification of Fe3O4 magnetic nanoparticles using carboxymethyl-β-cyclodextrin. Prepared nanoparticles were characterized by X-ray diffraction analysis, transmission electron microscope, Fourier transform infrared spectroscopy, dynamic light scattering and vibrating sample magnetometer. The β-cyclodextrin modified Fe3O4 nanoparticles have a narrow size distribution with mean diameter about 10 nm. They exhibit superparamagnetic properties at room temperature with saturation magnetization of 48 emu/g. Since, the most reported technologies for arsenic removal are more effective in removing As(V) rather than As(III), the adsorption ability of these nanoparticles was investigated for removing As (III) from aqueous solution. The adsorption behavior of this material can be influenced by various factors such as contact time, pH, adsorbent dosage and initial concentration of As(III), which their effects were studied. Equilibrium data were fitted by Langmuir isotherm and the maximum removal percentage was obtained about 85% at optimum conditions. Using these modified Fe3O4 nanoparticles, the arsenic concentrations can be reduced to the allowed limits declared by the World Health Organization.
Elmira Ghadamnan; Seyed Reza Nabavi; Mahmoud Abbasi
Abstract
In the present study, nano zeolite A (LTA) was synthesized by the alkaline fusion method without adding an organic template. Effect of temperature and aging time were studied on the crystallinity and morphology of the final product. The synthesized LTA was characterized by scanning electron microscopy ...
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In the present study, nano zeolite A (LTA) was synthesized by the alkaline fusion method without adding an organic template. Effect of temperature and aging time were studied on the crystallinity and morphology of the final product. The synthesized LTA was characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC) and N2 adsorption/desorption technique. The prepared nano LTA zeolite was applied to the water softening process. The main effects and interaction of factors such as pH, the amount of LTA, initial total hardness, temperature and contact time were investigated by response surface methodology (RSM). The obtained optimum values of factors were applied to hard water to remove Ca2+ and Mg2+ ions. Pseudo-first and second-order models were applied to kinetic and rate data. It was found that the adsorption rate follows the pseudo-second-order kinetic model.
Morteza Asghari; Mostafa Dehghani; Hossein Riasat Harami; Amir Hossein Mohammadi
Abstract
In this communication, an advanced, simultaneous mass and heat transfer model has been developed to take a meticulous glance on the influences of different parameters on Persian Gulf seawater desalination using Sweeping Gas Membrane Distillation (SGMD) technique. This essay focuses on the increasing ...
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In this communication, an advanced, simultaneous mass and heat transfer model has been developed to take a meticulous glance on the influences of different parameters on Persian Gulf seawater desalination using Sweeping Gas Membrane Distillation (SGMD) technique. This essay focuses on the increasing the distillate flux by investigation of the physical properties and feed temperature of the sweeping gas membrane distillation on the seawater desalination. The effects of operating parameters, including feed temperature, salt concentration, sweeping gas temperature, and heat transfer coefficient on the distillate flux of the Persian Gulf seawater have been investigated. The effect of feed temperature on temperature polarization has also been studied. By increasing the feed temperature from 25 oC to 60 oC, the temperature polarization increases and the polarization coefficient (TPC) decreases; for instance, for membranes with PP, the TPC decreases from 0.95 to 0.905. By increasing the feed temperature, higher fluxes are achieved for both the gas velocities. Therefore, by increasing the feed temperature from 50 oC up to 80 oC, the distillate flux grows 9 times. Also, the distillate flux for membrane with PVDF as polymer increased from 0 to 4.2 by increasing the feed temperature from 40 oC to 70 oC. The model predictions show a small error of 3.6% with the experimental data reported in literature which indicates the reliability of simulated results.