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.
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.