Search for: ion-exchange-resins
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    Study on Separation of Uranium from Phosphoric Acid by Column Chromatography

    , M.Sc. Thesis Sharif University of Technology Grayeli, Fatemeh (Author) ; Sohrabpour, Mostafa (Supervisor) ; Khanchi, Ali Reza (Supervisor) ; Outokesh, Mohammad (Supervisor)
    In this study, uranium removal from phosphoric acid with doulite resin was examined. Different uptake properties of the doulite resin were examined using batch, stirred and column methods. Langmuier, freundlich and dubinin equation was fitted the isotherm data and freundlich equation showed the best fitting. Adsorption kinetics was controlled by slow intraparticle diffusion of UO22+ ions in resin, and it obeyed a shrinking core model. Also a pseudo-second order chemical reaction fairly fitted the kinetics data  

    Kinetic study of catalytic hydrolysis reaction of methyl acetate to acetic acid and methanol

    , Article Iranian Journal of Science and Technology, Transaction B: Engineering ; Volume 30, Issue 5 , 2006 , Pages 595-606 ; 03601307 (ISSN) Ehteshami, M ; Rahimi, N ; Eftekhari, A. A ; Nasr, M. J ; Sharif University of Technology
    The reaction kinetics and chemical equilibrium of the reversible catalytic hydrolysis reaction of a methyl acetate to acetic acid and methanol using a strongly acidic ion exchange resin catalyst named Amberlyst 15 were studied. To investigate the different behavior of Amberlyst 15 in the adsorption of reactants and product species, the equilibrium behavior of binary non-reactive liquid mixtures, consisting of one reactant and one product were studied experimentally. The Langmuir model was used to describe the equilibrium condition, quantitatively. Then the employed model was compared with the more complicated thermodynamic models to describe the equilibrium between the catalytic polymer... 

    Comparison of the batch and breakthrough properties of stable and plain alginate microcapsules with a chelating resin and an ion exchanger in Ag+ adsorption

    , Article Industrial and Engineering Chemistry Research ; Volume 47, Issue 17 , 5 August , 2008 , Pages 6742-6752 ; 08885885 (ISSN) Outokesh, M ; Niibori, Y ; Mimura, H ; Ahmadi, S. J ; Sharif University of Technology
    A comparative study on the uptake properties of alginate microcapsules containing Cyanex 302 extractant, Lewatite TP 214 chelating resin, and Amberlite 200CT strongly acidic ion exchanger has been conducted using Ag+ as the target ion. The study resulted in an analytical formula, as well as three phenomenological breakthrough formulas that are also applicable in other fixed-bed operations. It also demonstrated a close similarity of the uptake properties of alginate microcapsules (MCs) and the chelating resins. Advantages of MCs over chelating resins include ease of preparation, ability to immobilize different extractants, and, most remarkably, an enormous distribution factor (Kd ≈ 106... 

    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) Semnani, F ; Asadi, Z ; Samadfam, M ; Sepehrian, H ; Sharif University of Technology
    Elsevier  2012
    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... 

    Immobilization of Spent Ion Exchange Resins from Bushehr Nuclear Power Plant

    , M.Sc. Thesis Sharif University of Technology Bamshad, Zahra (Author) ; Samadfam, Mohammad (Supervisor) ; Davarkhah, Reza (Supervisor) ; Tavasoli, Maryam (Co-Advisor)
    Ion exchange resins are widely used in nuclear industries. These spent resins result in the production of a large amount of low and intermediate level radioactive wastes, therefore, the treatment and immobilization of spent ion exchange resins are the major problems in the development of nuclear power plants.In this research, in a laboratory scale, we tried to find the suitable procedure and formulation to immobilize a specific group of cation-exchange resins which is used in Bushehr nuclear power plant (AMBERLITE IRN-97H) in the cement matrix. The solidification matrix consists of five constituents: anti sulfate slag type portland cement, cation-exchange resins, diatomite, sodium hydroxide... 

    Comments on the " A comparative study of chelating and cationic ion exchange resins for the removal of palladium (II) complexes from acidic chloride media"

    , Article Journal of Hazardous Materials ; Volume 229-230 , 2012 , Pages 461-462 ; 03043894 (ISSN) Alahyari, S. A ; Khanchi, A. R ; Outokesh, M ; Tayebi, A ; Sharif University of Technology

    Study on Immobilization of the Spent Ion Exchange Resins of Tehran Research Reactor in Borosilicate Glass

    , M.Sc. Thesis Sharif University of Technology Rastgoo, Pouria (Author) ; Samadfam, Mohammad (Supervisor) ; Yadollahi, Ali (Supervisor) ; Sepehrian, Hamid (Co-Supervisor)
    Considering the operation of the current nuclear reactors and the country's policy to achieve 10,000 megawatts of nuclear power in the horizon of 1420, as well as the construction of research reactors, we will face a huge amount of radioactive waste in the coming years. Meanwhile, spent ion exchange resins constitute a large amount of low and intermediate level (LILW) solid radioactive waste produced from the nuclear industry. Therefore, appropriate precautionary measures should be taken for the immobilization and disposal of these radioactive wastes in order to ensure the sustainable development of the nuclear industry and the protection of the environment and human health. In this study,... 

    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) Tavakoli, H ; 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... 

    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) Kowsari, M. R ; 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.... 

    Adsorption behavior of Sb(III) in single and binary Sb(III)—Fe(II) systems on cationic ion exchange resin: adsorption equilibrium, kinetic and thermodynamic aspects

    , Article Transactions of Nonferrous Metals Society of China (English Edition) ; Volume 30, Issue 1 , January , 2020 , Pages 236-248 Moghimi, F ; Jafari, A. H ; Yoozbashizadeh, H ; Askari, M ; Sharif University of Technology
    Nonferrous Metals Society of China  2020
    The present study dealt with the mechanism of competitive adsorption of Sb(III) and Fe(II) ions from a copper-containing aqueous solution on Purolite S957, a commercially available cationic ion-exchange adsorbent. Experiments were conducted using aqueous copper sulfate solutions containing either single or conjoint ions, using both sedentary and batch adsorption techniques to ascertain the sensitivity of the adsorption process to variation in pH, mass of resin, contact time, and temperature as well as establishing the optimal range of variables for maximum ion removal. The data from single ion adsorption tests were fitted by non-linear regression techniques to Henry, Langmuir, Freundlich,... 

    Drug loading onto ion-exchange microspheres: Modeling study and experimental verification

    , Article Biomaterials ; Volume 27, Issue 19 , 2006 , Pages 3652-3662 ; 01429612 (ISSN) Abdekhodaie, M. J ; Wu, X. Y ; Sharif University of Technology
    A new mathematical model was developed and an exact analytical solution without approximations of previous work was derived for the description of the kinetics and equilibrium characteristics of drug loading from a finite external solution onto ion-exchange microspheres. The influence of important parameters pertinent to material properties and loading conditions on the kinetics, efficiency, and equilibrium of drug loading was analyzed using the developed model and equations. The numerical results showed that the rate of drug loading increased with increasing initial drug concentration in the solution or with the relative volume of the external solution and the microsphere. The maximum...