Search for: sepehrian--h
Article International Journal of Engineering, Transactions A: Basics ; Volume 30, Issue 1 , 2017 , Pages 1-6 ; 17281431 (ISSN) ; Sepehrian, H ; Sharif University of Technology
Materials and Energy Research Center 2017
Removal of fluoride ions was investigated using a new adsorbent of yttrium alginate biocomposite (YALG). Effect of various parameters such as pH, contact time, initial concentration of fluoride ions and temperature on the sorption capacity of adsorbent was studied. Performing a mathematical assessment of fluoride sorption, isotherm and kinetics models including Freundlich & Langmuir isotherms and pseudo first & second order kinetics were applied on experimental equilibrium results through this work. Isotherm analysis revealed that Langmuir model showed a better evaluation from sorption equilibrium data than Freundlich. Based on kinetics evaluation, the pseudo second-order equation was...
Recovery of uranium from UCF liquid waste by anion exchange resin CG-400: Breakthrough curves, elution behavior and modeling studies, Article Annals of Nuclear Energy ; Volume 54 , April , 2013 , Pages 149-153 ; 03064549 (ISSN) ; Sepehrian, H ; Semnani, F ; Samadfam, M ; Sharif University of Technology
Continuous fixed-bed column studies were carried out by using Amberlite CG-400 anion exchange resin for the recovery of uranium from aqueous solutions (synthetic solutions and uranium conversion facility (UCF) liquid waste). Effects of operating parameters such as flow rate and bed height were studied. The breakthrough capacity decreases with increasing flow rate, but this dependence was not significant with a long column. The maximum breakthrough capacity of uranium ions were achieved by CG-400 resin at a flow rate of 0.2 mL min-1 and bed height 9.1 cm (4 g resin). The elution behavior of uranium from CG-400 resin by various eluents have been investigated and the results show that 0.5 mol...
Uranium(VI) sorption behavior onto amberlite CG-400 anion exchange resin: Effects of pH, contact time, temperature and presence of phosphate, Article Annals of Nuclear Energy ; Volume 48 , October , 2012 , Pages 21-24 ; 03064549 (ISSN) ; Asadi, Z ; Samadfam, M ; Sepehrian, H ; Sharif University of Technology
In this paper, uranium sorption onto amberlite CG-400 anion exchange resin in the presence of phosphate anions was studied. The effect of contact time between the sorbent and aqueous solution, pH, initial concentration of uranium and temperature were also investigated. Kinetic studies show that uranium sorption onto amberlite CG-400 resin in the presence of phosphate is a fast process and follows pesudo-second-order kinetics. It was also found that the pH value and the presence of phosphate play very important roles in the uranium sorption onto CG-400 resin. Optimum pH for uranium sorption in the presence of phosphate anions was about 3.5. The experimental sorption isotherm is successfully...
Synthesis, characterization, and cesium sorption performance of potassium nickel hexacyanoferrate-loaded granular activated carbon, Article Particulate Science and Technology ; Vol. 32, issue. 4 , 2014 , pp. 348-354 ; ISSN: 02726351 ; Samadfam, M ; Fasihi, J ; Grayeli Fumeshkenar, F ; Sepehrian, H ; Sharif University of Technology
GAC has been modified by loading of potassium nickel hexacyanoferrate (KNiCF) as a new adsorbent for cesium adsorption. The potassium nickel hexacyanoferrate-loaded granular activated carbon (KNiCF-GAC) was characterized using powder x-ray diffraction (XRD) and nitrogen adsorption-desorption isotherm data, infrared spectroscopy, and its cesium adsorption performance in aqueous solution was investigated. The effect of the various parameters such as initial pH value of the solution, contact time, temperature, and initial concentration of the cesium ion on the adsorption efficiencies of KNiCF-GAC have been studied systematically by batch experiments. The adsorption isotherm of KNiCF-GAC was...
Uranium recovery from UCF liquid waste by nanoporous MCM-41: Breakthrough capacity and elution behavior studies, Article Research on Chemical Intermediates ; Volume 39, Issue 3 , 2013 , Pages 951-959 ; 09226168 (ISSN) ; Tavakoli, H ; Samadfam, M ; Semnani, F ; Asadi, Z ; Sepehrian, H ; Sharif University of Technology
Adsorption and recovery of uranium by nanoporous MCM-41 from aqueous solutions (synthetic solution and uranium conversion facility liquid waste) were investigated by use of a fixed-bed column (1.2 cm diameter and 3.0 cm height). Adsorption was carried out at flow rates 0.2 and 0.5 mL min-1, which correspond to retention times of 10 and 6 min. The maximum breakthrough capacity for uranium ions was achieved by use of nanoporous MCM-41 at the optimum pH of 3.6 and flow rate 0.2 mL min-1 (61.95 μg g-1). The Thomas and Yan models were applied to the experimental data, by use of linear regression, to determine the characteristics of the column for process design. The breakthrough curves calculated...
Adsorptive behavior of an amberlite anion exchanger resin for uranium (VI) sorption in the presence of sulfate anions, Article International Journal of Engineering, Transactions B: Applications ; Volume 29, Issue 2 , 2016 , Pages 170-175 ; 1728144X (ISSN) ; Sepehrian, H ; Fasihi, J ; Arabieh, M ; Mahani, M ; Sharif University of Technology
Materials and Energy Research Center
Uranium (VI) sorption using an anionic exchanger resin, namely Amberlite IRA910, in the presence of sulfate anions was the subject of current study. Batch sorption experiments were carried out to evaluate the influence of operational parameters such as pH, contact time, initial concentration and existence of various anions (including phosphate, sulfate, chloride, fluoride, and nitrate) in the solution on Amberlite IRA910 sorption behavior. Experiments revealed that uranium adsorption was fulfiled at pH>3 and 50 min to amount of 80%. Kinetics study revealed that the pseudo-second-order model showed better curve-fitting regression of the experimental data than the pseudo-first-order one....
Synergistic coupled transport of uranyl ion across bulk liquid membrane mediated by dioxa-diazamacrocycle and oleic acid, Article Journal of Radioanalytical and Nuclear Chemistry ; Volume 316, Issue 1 , 2018 , Pages 9-16 ; 02365731 (ISSN) ; Fasihi, J ; Samadfam, M ; Sepehrian, H ; Ashtari, P ; Mahani, M ; Arabieh, M ; Sharif University of Technology
Springer Netherlands 2018
Synergistic coupled transport of uranyl ion across a bulk liquid membrane of chloroform has been investigated using a dioxa-diazamacrocycle and oleic acid as carrier and synergistic agents, respectively. Quantitative transport of uranyl ion was achieved within 4 h when the pH of source solution was kept at 5.0–6.0 and mole ratio of carrier to synergistic agent was 1/15. It was found that overall rate and selectivity of the transport is governed by the stripping step. Finally, the influence of some foreign competitor ions including Al3+, Ca2+, CO3 2−, Cu2+, Mg2+, Pb2+, Zn2+ and Th4+ and also the ionic strength on the transport efficiency has been evaluated. © 2018, Akadémiai Kiadó, Budapest,...