Alireza Behzadi; Amirhosein Yazdanbakhsh
Abstract
Recently, there has been growing concern about the presence of pharmaceutical compounds and particularly antibiotics as emerging contaminants. This study employed high specific surface area organic aerogels to remove Tetracycline antibiotics. For this purpose, resorcinol formaldehyde aerogel (RF) was ...
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Recently, there has been growing concern about the presence of pharmaceutical compounds and particularly antibiotics as emerging contaminants. This study employed high specific surface area organic aerogels to remove Tetracycline antibiotics. For this purpose, resorcinol formaldehyde aerogel (RF) was synthesized via the sol-gel process and dried under ambient drying conditions. The synthesized RF aerogel was modified by incorporating 1 wt.% graphene with 1 wt.% m-phenylenediamine during the synthesis process to prepare RF-G1/PmPDA1. Eventually, the performance of the synthesized samples as adsorbents was evaluated under various parameters such as the effects of pH values (2-12), adsorbent dose (4-10 mg), and adsorbent with antibiotics contact time (3-24 h). FTIR, FESEM, BET, CHN, and EDS tests were conducted to characterize the samples. Afterward, the adsorption rate of Tetracycline antibiotics was measured using UV-Vis. The BET test results revealed that the modification of the RF aerogel sample also increased the specific surface area from 96 to 308 m2/g. The results also discovered that the removal rate of Tetracycline antibiotics for the RF aerogel and RF-G1/PmPDA1 was obtained to be 65.2% and 93.3% at optimal pH of 4 and 4, respectively.
Najmeh Atoub; Ahmad Amiri; Alireza Badiei; Jahan B. Ghasemi
Abstract
In this study, thiol-functionalized nanostructure silica type MCM-41 was successfully prepared via the facile one-pot hydrothermal method with low amounts of the directing agent. The mesoporous silica indicated a remarkable adsorption behavior toward Pb(II) ions without any interference of the competing ...
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In this study, thiol-functionalized nanostructure silica type MCM-41 was successfully prepared via the facile one-pot hydrothermal method with low amounts of the directing agent. The mesoporous silica indicated a remarkable adsorption behavior toward Pb(II) ions without any interference of the competing ions. The main experimental variables affecting removal efficiency of the adsorbent were examined, and the optimized conditions were achieved as to be 6, 50 mg, and 30 min for solution pH, the adsorbent dosage, and contact time, respectively. The adsorbent was triumphantly used for the removal of Pb (II) ion from real water samples with a notable removal efficiency as 95%. The concentrations of the competitive ions in the solution were about 10 to 100 times more than Pb (II) ions. The results show that other ions had no interfering effect on the removal efficiency of Pb (II) ions. It means that SH-SiO2 has excellent selectivity for Pb (II) ions and is an appropriate candidate for removing Pb (II) ions from the real samples.
Mohammad Reza Mohammad Shafiee; Janan Parhizkar; Sasan Radfar
Abstract
Homogenous catalysis which the catalyst operates in the same phase as the reactants is definitely efficient in catalysis processes while it suffers from the impossibility or inconvenience of the removal of the catalyst from the reaction media. In this research, In2S3 nanoparticles were synthesized by ...
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Homogenous catalysis which the catalyst operates in the same phase as the reactants is definitely efficient in catalysis processes while it suffers from the impossibility or inconvenience of the removal of the catalyst from the reaction media. In this research, In2S3 nanoparticles were synthesized by a simple precipitation method and then immobilized and stabilized in the porous structure as a substrate. The properties of pure hydrogel and In2S3 in hydrogel were characterized by FTIR, DRS, XRD, BET, BJH, FESEM, and EDX. The DRS results confirmed that the stabilization of nanoparticles in hydrogel led to redshift of bandgap. The hydrogel with In2S3 showed a more porous structure in comparison with pure hydrogel. Because of the decrease of bandgap and increase of specific surface area, In2S3 nanoparticles stabilized in hydrogel removed Rhodamine B (RhB) as a model pollutant very well. The performance of catalyst in the removal of RhB under dark condition (adsorption) and visible light irradiation (photocatalysis) was investigated and 77.7% and 95.2% of dye removal percentage were obtained in 120 min under dark and light irradiation, respectively. In conclusion, immobilization In2S3 as a high-efficiency visible light photocatalyst in hydrogel provided promising heterogeneous and reusable catalyst for water treatment
Ramin Yavari
Abstract
In the present research work, zirconium oxide coated on activated alumina (Al2O3-90, Al2O3-60) were synthesized and used along with their pristine materials to investigate and compare the adsorption behavior of fluoride on them. These material was characterized by BET and X-ray diffraction analyzer. ...
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In the present research work, zirconium oxide coated on activated alumina (Al2O3-90, Al2O3-60) were synthesized and used along with their pristine materials to investigate and compare the adsorption behavior of fluoride on them. These material was characterized by BET and X-ray diffraction analyzer. The obtained results confirmed that the immobilization of ZrO2 particles on the external surface pore of Al2O3-60 and Al2O3-90 has been performed successfully. The results of adsorption behavior study show that among these adsorbents, the synthesized hybrid material “Al2O3-60-ZrO2” has high affinity toward the adsorption of fluoride ions from aqueous solution under ambient condition (36.62 mg.g-1). Adsorption data in all of adsorbents were fitted with Langmuir model and the calculated E value shows that the chemical sorption process is a dominant mechanism in adsorption process. In the first 80 minutes of contact time, the maximum adsorption of fluoride was found to be for these synthesized hybrids” Al2O3-60-ZrO2, Al2O3-90-ZrO2”. The adsorption rate of fluoride ions on these hybrid materials in spite of their initial material was almost independent on pH value in the range 3 to 8. The negative values of ΔG° indicates that the adsorption process of fluoride ions onto these adsorbents is exergonic and will proceed spontaneously. In addition, overall, the obtained results show that the prepared hybrid materials as adsorbents are promising and potential candidate for the adsorption and removal of trace amount of fluoride from nuclear and chemical wastewater.
Taher Yousefi; Mohammad Abas Mohsen; Hamid Reza Mahmudian; Meisam Torab-Mostaeidi; Mohammad Ali Moosavian; Hassan Aghayan
Abstract
In the current work, the natural zeolite was modified with cobalt hexacyanoferrate and employed for adsorbent of Pb(II) ions from aqueous solution. The modification was approved by XRD and FTIR techniques. The Pb(II) adsorption capacity enhanced by 1.8 times from 60 mg/g (natural zeolite) to 100 mg/g ...
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In the current work, the natural zeolite was modified with cobalt hexacyanoferrate and employed for adsorbent of Pb(II) ions from aqueous solution. The modification was approved by XRD and FTIR techniques. The Pb(II) adsorption capacity enhanced by 1.8 times from 60 mg/g (natural zeolite) to 100 mg/g (modified zeolite) at optimal conditions. Factors such as time, pH, temperature, adsorbent dosage and initial concentration were investigated to optimize the adsorption condition. A fast sorption was observed in the initial contact time and equilibrium was achieved in less than 120 min. The optimum pH for lead removal was between 3 and 6. The adsorption capacity was increased and reached the maximum of 90 % at 2 g/L adsorbent dosage. Also, the adsorption increased as the concentration increased up to 500 mg/L and the sorption became constant at higher concentration. It was found that the double-exponential model describes the lead sorption kinetics and the Langmuir–model describe the isotherms.