Hassan Karami; Seyyed Kazem Kazemi
Abstract
The work is a feasible study about the performance of woody skin and outer soft shell of Hazelnut for the removal of lead ions from water. The Hazelnut woody skin and soft outer shell are crushed by an innovative ball mill to prepare micro and nano powders. TEM images show that the produced nano powder ...
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The work is a feasible study about the performance of woody skin and outer soft shell of Hazelnut for the removal of lead ions from water. The Hazelnut woody skin and soft outer shell are crushed by an innovative ball mill to prepare micro and nano powders. TEM images show that the produced nano powder includes uniform nanoparticles with 8-10 nm average diameters. The produced nanoparticles were used as a suitable and effective biosorbent to remove lead ions from water. Experimental data shows that the adsorption of lead ions on the surface of hazelnut skin nanoparticles is acceptably fitted to Langmuir isotherm model. Based on the Langmuir isotherm, a maximum adsorption capacity of 91 mg g-1 is achieved for adsorption of lead ions on the surface of hazelnut skin nanoparticles. The obtained results showed that the best removal of lead ions can be done under conditions includes 50 ml initial solution, pH=4, 120 mg L-1 initial concentration of lead ions per 70 mg biosorbent for contact time of 20 minutes at room temperature. The adsorbed ions are easily eluted by 1.5 ml 0.7 M HNO3 solution. Under the optimal conditions, preconcentration factor of 200, %RSD of less than 5% with detection limit of 100 ppb are obtained. The effects of some interfering ions such as Fe2+, Cu2+, Mg2+, Zn2+, Mn2+ and Ni2+ on the removal efficiency of lead ions were studied. The presented method is successfully applied for removal and determination of lead ions from real samples.
Hassan Karami; Foroozandeh Taala; Mohammad Ali Karimi; Reza Behjat-Manesh Ardakani
Abstract
In this work, sub-micro and nanometer sized Mg and Mg/carbon composites as anode materials of Mg-air batteries is prepared by using an innovative rotary ball mill. Characterization of the prepared samples is performed by dynamic light scattering, scanning electron microscopy, transmission electron microscopy ...
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In this work, sub-micro and nanometer sized Mg and Mg/carbon composites as anode materials of Mg-air batteries is prepared by using an innovative rotary ball mill. Characterization of the prepared samples is performed by dynamic light scattering, scanning electron microscopy, transmission electron microscopy and, X-ray diffraction techniques. The effects of milling time and amount of carbon additive are evaluated on the sizes of Mg particles in different samples, the discharge capacities and also other electrochemical performances of both primary and secondary magnesium air batteries. An aqueous solution of 2 M Magnesium Chloride and 3 M Sodium Chloride and an organic solution of 0.2 M I2 in Dimethyl Sulfoxide are used as electrolytes in primary and secondary Mg-air batteries, respectively. The Mg sample T6 with average particle size of 170 nm and the Mg/carbon composite sample T13 with average particle size of 35 nm show the highest discharge capacities in both primary (333.1 and 418.6 mA.h g-1) and secondary (354.4 and 433.9 mA.h g-1) Mg-air batteries, respectively. The cycle life test was examined on all constructed rechargeable Mg-air batteries over 30 cycles.
Hassan Karami; Fariba Goli
Volume 3, Issue 1 , March 2016, , Pages 55-62
Abstract
Water pollution by heavy metal ions such as Pb occur globally. The conventional methods for the heavy metal ions removal from the water include electrochemical and chemical precipitations, ion exchange, reverse osmosis and sorption. Among the above mentioned different methods, sorption of heavy metal ...
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Water pollution by heavy metal ions such as Pb occur globally. The conventional methods for the heavy metal ions removal from the water include electrochemical and chemical precipitations, ion exchange, reverse osmosis and sorption. Among the above mentioned different methods, sorption of heavy metal ions on the surface of solid nanomaterials is one of the most recommended and interest methods. Sorption is attractive due to its merits of efficiency, cheap and simple operation. In this study, hematite/magnetite/iron nanocomposite (MHINC) is synthesized by the low voltage electrical arc method in the presence of 1.2 Tesla external magnetic fields. Scanning electron microscopy and transmission electron microscopy show that the synthesized MHINC includes uniform nanoparticles with 7 nm average diameters. The prepared MHINC is used as a new sorbent to remove heavy metal ions from polluted waters. Experimental data shows that the sorption of lead ions on the surface of MHINC is acceptably fitted to the Langmuir isotherm. Based on the experimental data, a maximum sorption capacity of 86 mg g-1 is achieved for the sorption of lead ions on the surface of MHINC. The experimental optimum conditions for the lead ion removal includes pH=5, 25 ml sample volume, 25 mg sorbet and 25 min mixing time in the room temperature. Desorption studies showed the adsorbed lead ions on MHINC surface can be done by using 1ml acidic solution containing 3 M HCl and 2 M HNO3.
Hassan Karami; Bahr Ali Najafi
Volume 2, Issue 2 , September 2015, , Pages 127-137
Abstract
Hydrous manganese dioxide nanoclusters are prepared by the oxidation of manganese (II) ions with ammonium persulfate and used as a new sorbent for Ag+ ion removal from aqueous medium. The synthesized compound is characterized using scanning electron microscopy, dynamic light scattering, energy dispersive ...
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Hydrous manganese dioxide nanoclusters are prepared by the oxidation of manganese (II) ions with ammonium persulfate and used as a new sorbent for Ag+ ion removal from aqueous medium. The synthesized compound is characterized using scanning electron microscopy, dynamic light scattering, energy dispersive analysis of X-rays, X-ray diffraction and BET surface measurements. Scanning electron microscopy images showed that the synthesized Hydrous manganese dioxide nanoclusters include cactus-shaped nanoclusters with uniform needles of average diameter of 36 nm and length of 1000 nm. X-ray diffraction data reveal that γ-MnO2 is formed in this method. Batch experiments are carried out to evaluate the Ag+ adsorption capacity of Hydrous manganese dioxide nanoclusters. The maximum adsorption capacity estimated by the Langmuir model was 81.97 mg g-1 for Ag+. Silver ion adsorption on Hydrous manganese dioxide nanoclusters is a fast process and the kinetics followed a pseudo-second-order rate equation. The removal efficiency of Ag+ depends on Hydrous manganese dioxide nanoclusters amount, pH and temperature of the solution. The presences of Na+, Ca2+ and Mg2+ ions in the concentrations lower than 200 ppm have no significant influence on silver ion removal. The adsorbed ions can easily eluted by the small volume of a solution consisting thiourea and hydrochloric acid. Finally, the experimental data show that the synthesized Hydrous manganese dioxide nanoclusters can quantitatively remove silver ions from real water samples.
