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%.
Kamal Alizadeh; Esmail Khaledyan; Yagoub Mansourpanah
Abstract
In this study, a selective, fast and novel magnetic mesoporous silica sorbent Fe3O4@MCM-41-NH2, was synthesized, functionalized and has been used for the removal of Pb+2 ions from aqueous solution. The characteristics of the Fe3O4@MCM-41-NH2 sorbent was investigated by XRD, VSM, SEM, TEM, ...
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In this study, a selective, fast and novel magnetic mesoporous silica sorbent Fe3O4@MCM-41-NH2, was synthesized, functionalized and has been used for the removal of Pb+2 ions from aqueous solution. The characteristics of the Fe3O4@MCM-41-NH2 sorbent was investigated by XRD, VSM, SEM, TEM, BET, and FT-IR. The response surface methodology (RSM) based on central composite design (CCD) was utilized for estimating the effects of parameters, namely contact time (min), pH, the quantity of adsorbent (g) and initial concentration of Pb+2. The quadratic model was used as the best model for guessing variables. The results of the analysis of variance for this model were obtained with a high F-value (50.28), very low P-value (<0.0001) and non-significant lack of fit (0.2251). The maximum adsorption capacity was obtained at 46.08 mg/L. Fitting equilibrium data with different isotherm models shows that Freundlich isotherm was the best-fitted model. The pseudo-second-order model was the best model for fitting experimental data.
Hossein Mohammadifard; Mohammad C. Amiri
Abstract
Heavy metals pollution in the environment is one of the serious problems in the field of water and wastewater management. In this study; calcium carbonate nanoparticles, synthesized by an efficient and novel method, were used as an adsorbent for the removal of lead and iron from aqueous solutions. To ...
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Heavy metals pollution in the environment is one of the serious problems in the field of water and wastewater management. In this study; calcium carbonate nanoparticles, synthesized by an efficient and novel method, were used as an adsorbent for the removal of lead and iron from aqueous solutions. To study the mechanism of adsorption, the kinetic and isotherm models were examined. The adsorption kinetics of process was found to follow a pseudo-second-order equation. The maximum monolayer adsorption capacities of calcium carbonate nanoparticles calculated from Langmuir isotherm were found to be 1210±30 mg/g for Pb(II) and 845±8 mg/g for Fe(II) ions, respectively. The response surface methodology based on three variable Box-Behnken design was utilized to evaluate the effects of temperature (25-65 oC) and initial metal concentration (10-200 mg/L) on the sorption process. The optimum conditions for the removal process using calcium carbonate nanoparticles were found to be 200 mg/L at 25 oC. Experimental data demonstrated that a precipitation transformation mechanism rather than adsorption enhances the removal efficiency.
Seyed Hassan Sharifi; Hassan Shoja
Abstract
The purpose of this investigation is to study the influence of Spruce sawdust (SD) coated by magnesium oxide (MgO) nanoparticles in the removing of methylene blue (MB) from an aqueous solution which is in a batch system. The adsorbent was characterized by FTIR, FE-SEM, BET and XRD analysis. The high ...
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The purpose of this investigation is to study the influence of Spruce sawdust (SD) coated by magnesium oxide (MgO) nanoparticles in the removing of methylene blue (MB) from an aqueous solution which is in a batch system. The adsorbent was characterized by FTIR, FE-SEM, BET and XRD analysis. The high adsorption potential of SD-MgO nano-biocomposite was revealed by these findings, therefore, it is usable for dye-containing wastewater treatment. By investigating the impact of particular conditions like MB concentrations, the dose of adsorbent and pH, it became possible to confirm the effectiveness of the process. The OOP (which stands for Optimum Operating Parameters) were evaluated by RSM (which stands for Response Surface Methodology) which is based on BBD (Box-Behnken design) and is used for removing MB dye. The adsorbent dosage is the highest effective degree of the individual factor on MB removal. Maximum removal of MB dye was detected at pH 11 with 3.50 g L-1 adsorbent dosage. The surface area of 0.873 m2 g-1 and mesoporous adsorbent prepared gave good adsorption capacity of 26.657 mg g-1 for MB. Furthermore, in order to predict the empirical variables’ significance, the variances’ analysis (ANOVA) was used. The predicated removal efficiency which is proved to be the potency of the process and its effectiveness was found to be 94.05%. Different equilibrium and kinetic models were utilized to the experimental data. Both Pseudo-second order kinetic model and Freundlich adsorption isotherm showed the better fitness to the experimental data.
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.
Shahryar Jafarinejad; Mohammad Faraji; Zohreh Norouz; Javad Mokhtari-Aliabad
Abstract
Even at low levels, heavy metals are toxic and can damage living things. They do not break down or decompose and tend to build up in plants, animals, and people causing health concerns. Magnetic nanoparticles (MNPs) can be considered as potential adsorbents for the removal of cadmium (Cd2+) from aqueous ...
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Even at low levels, heavy metals are toxic and can damage living things. They do not break down or decompose and tend to build up in plants, animals, and people causing health concerns. Magnetic nanoparticles (MNPs) can be considered as potential adsorbents for the removal of cadmium (Cd2+) from aqueous solutions because of their high surface area and the combined effect of adsorption and separation under external magnetic fields. In this study, a novel sulfur-modified magnetic nanoparticle was applied as an adsorbent for the removal of Cd2+ ions from aqueous solutions. The adsorbent was characterized by scanning electron microscopy (SEM), Fourier transform-infrared (FT-IR) spectroscopy, and thermogravimetric analysis (TGA). The effects of pH, contact time, and initial concentration of Cd2+ on the removal efficiency of it were investigated in batch adsorption experiments. The equilibrium data fitted the Langmuir isotherm model better than the Freundlich isotherm model, and they were well explained in terms of pseudo-second-order kinetics. The maximum monolayer capacity qm and KL the Langmuir constant were calculated from the Langmuir as 5.1867 mg/g and 0.1562 L/mg, respectively.
Mehrzad Arjmandi; Majid Peyravi; Mahdi Pourafshari Chenar; Mohsen Jahanshahi; Abolfazl Arjmandi
Abstract
To investigate the adsorption property of H2 and CO2 on the organic ligand of C-MOF-5 (H2BDC) and T-MOF-5 (ZnO-doped H2BDC (ZnO-H2BDC)), Density functional theory (DFT) method was performed. First, the adsorption of ZnO on H2BDC resulted in examining binding energies, the charge transfer, density of ...
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To investigate the adsorption property of H2 and CO2 on the organic ligand of C-MOF-5 (H2BDC) and T-MOF-5 (ZnO-doped H2BDC (ZnO-H2BDC)), Density functional theory (DFT) method was performed. First, the adsorption of ZnO on H2BDC resulted in examining binding energies, the charge transfer, density of states, dipole moments and adsorption geometries were investigated. The binding properties have been calculated and investigated theoretically for ZnO-doped H2BDC in terms of binding energies, band structures, Mulliken charges, and density of states (DOSs). According to obtained results, the H2BDC was strongly doped with ZnO. H2 and CO2 adsorption capacities for ZnO-doped H2BDC are significantly enhanced while there are low adsorption capacities for H2BDC. According to results, at least in the organic ligand of the MOF-5, the highest and lowest adsorption of CO2 (or H2) is attributed to the T-MOF-5 and C-MOF-5 respectively. Our calculations reveal that ZnO-doped H2BDC system (T-MOF-5) has much higher adsorption energy and higher net charge transfer value than pristine H2BDC (C-MOF-5). Also by changing in structure from cubic to tetragonal, the main site for H2 and CO2 adsorption was changed.
Marjan Tanzifi; Marzieh Kolbadi nezhad; Kianoush Karimipour
Abstract
The present work seeks to investigate the ability of polypyrrole/titanium dioxide nanocomposite to adsorb cadmium ions from aqueous solution. The impact of various experimental conditions, including solution pH, adsorbent dosage, adsorption time and initial concentration on the uptake of cadmium were ...
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The present work seeks to investigate the ability of polypyrrole/titanium dioxide nanocomposite to adsorb cadmium ions from aqueous solution. The impact of various experimental conditions, including solution pH, adsorbent dosage, adsorption time and initial concentration on the uptake of cadmium were studied. The adsorption kinetic was studied with the first-order, second-order, pseudo-first-order, pseudo-second-order and Morris–Weber models. The results revealed that adsorption process is controlled by pseudo-second-order model which illustrated that the adsorption process of cadmium is chemisorption-controlled. The adsorption capacity obtained from this model is 20.49 mg/g which close to the experimental value. The study yielded the result that when the initial concentration of the solution changed from 20 mg/l to 120 mg/l, the adsorption capacity increased from 0.99 to 24.52 mg/g. Further, Langmuir, Freundlich and Temkin isotherm models were applied to investigate the adsorption isotherm. Based on the results of the adsorption isotherm, Freundlich isotherm proved to be the best fit with the experimental data. Also, the morphology, chemical structure and thermal stability of adsorbent were studied by using SEM, EDX, FTIR, and TGA.
Saeed Tizro; Hadi Baseri
Abstract
Cobalt is one of the most hazardous heavy metals present in the environment. Magnetic based nanoadsorbents were used for removal of Co(II) ions in this work. The characteristics results of FT-IR, XRD, TGA, and FE-SEM show that applied coatings were modified magnetite nanoparticles efficiently. The results ...
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Cobalt is one of the most hazardous heavy metals present in the environment. Magnetic based nanoadsorbents were used for removal of Co(II) ions in this work. The characteristics results of FT-IR, XRD, TGA, and FE-SEM show that applied coatings were modified magnetite nanoparticles efficiently. The results of TEM indicate that magnetic nanoadsorbents were produced on the nanoscale with average particle sizes of 60±10 nm. Batch experiments were carried out to determine the removal efficiency of the nanoadsorbents. pH, temperature, contact time, adsorbent dose, shaking rate and the initial concentration of analyte were the studied parameters. At optimized conditions of operation parameters, the maximum removal percentage of 92% was obtained by using magnetite-citric acid as an adsorbent. Equilibrium data for Co(II) ions adsorption onto magnetite-citric acid were fitted well by Langmuir isotherm model and the maximum adsorption capacity for Co(II)ions was obtained 43.292 mg/g at 313 K. Also, thermodynamic parameters reveal the spontaneity, feasibility and endothermic nature of the Co(II) ions adsorption process. In addition, the cobalt ions can be desorbed from magnetite-citric acid nanoadsorbent by using nitric acid solution with 95% desorption efficiency and the magnetite-citric acid nanoadsorbent exhibits good recyclability.
Asadollah Mohammadi; Ali Aliakbarzadeh Karimi
Abstract
This study describes the adsorption and photocatalytic removal of methylene blue (MB) from aqueous solution by surface-modified TiO2 nanoparticles under ultraviolet irradiation in a batch system. The 5-sulfosalicylic acid grafted TiO2 (5-SA-TiO2) as a photocatalyst was characterized by means of ...
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This study describes the adsorption and photocatalytic removal of methylene blue (MB) from aqueous solution by surface-modified TiO2 nanoparticles under ultraviolet irradiation in a batch system. The 5-sulfosalicylic acid grafted TiO2 (5-SA-TiO2) as a photocatalyst was characterized by means of XRD, FTIR and SEM techniques. The surface of TiO2 nanoparticles was modified by 5-sulfosalicylic acid (5-SA) to increase performance by altering surface properties. Notably, in contrast with the adsorption process, the remarkable removal enhancement of MB dye was observed by photocatalytic degradation process from aqueous solution. The adsorption and photocatalytic degradation kinetics of MB using 5-SA-TiO2 nanoparticles have also been investigated. The results show that the photocatalytic degradation was good fit with the pseudo-first-order kinetic model (R2 > 0.99). The adsorption isotherm of MB onto modified TiO2 nanoparticles fitted into the Temkin equation. In addition, thermodynamic studies indicate the spontaneous behavior of adsorption and photocatalytic degradation processes.
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.
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.
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.