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    Sorption kinetics of oil spill by sorbent mineral material (expanded per lite)

    , Article CHISA 2006 - 17th International Congress of Chemical and Process Engineering, Prague, 27 August 2006 through 31 August 2006 ; 2006 ; 8086059456 (ISBN); 9788086059457 (ISBN) Safekordi, A. A ; Alihosseini, A ; Bastani, D ; Taghikhani, V ; Ordookhani, G ; Sharif University of Technology
    2006
    Abstract
    The present study examined the sorption capacity and sorption kinetics of four-type perlite for oil spills clean up. These four types are different on their porous space, expansion ability and special surface area. The tests were done both in static and dynamic methods. Experiments showed that the perlite spread on oil spill rapidly and floated on the surface of oil spill because of its low density (80-180 kg/m3). Scanning Electron Micrograph (SEM) of a typical structure of expanded perlite showed that it of high porous space. Sorption kinetic of oil spill into porous expanded perlite was evaluated by weight increase of crude oil with sorption time. According to kinetic study sorption of oil... 

    Removal of toxic metal ions from sungun acid rock drainage using mordenite zeolite, graphene nanosheets, and a novel metal–organic framework

    , Article Mine Water and the Environment ; Volume 35, Issue 1 , 2016 , Pages 18-28 ; 10259112 (ISSN) Rahimi, E ; Mohaghegh, N ; Sharif University of Technology
    Springer Verlag  2016
    Abstract
    We evaluated the sorptive properties of mordenite zeolite (MOR), a copper terephthalate metal–organic framework (MOF), and graphene oxide (GO) and their potential use in treating acid rock drainage (ARD) containing Fe3+, Cu2+, Mn2+, Zn2+, Pb2+, and Cd2+ ions. MOR was prepared via a hydrothermal method, MOF was prepared via a solvothermal method, and few-layered GO nanosheets were synthesized using Hummers’ method. The aqueous contaminants were removed by chemico-physical sorption and ion exchange in batch tests. It proved possible to dramatically improve removal efficiency and sorptive capacity by optimizing experimental conditions. Magnetic MOF crystals were more efficient in removing... 

    Numerical errors of explicit finite difference approximation for two-dimensional solute transport equation with linear sorption

    , Article Environmental Modelling and Software ; Volume 20, Issue 7 , 2005 , Pages 817-826 ; 13648152 (ISSN) Ataie Ashtiani, B ; Hosseini, S. A ; Sharif University of Technology
    2005
    Abstract
    The numerical errors associated with explicit upstream finite difference solutions of two-dimensional advection - Dispersion equation with linear sorption are formulated from a Taylor analysis. The error expressions are based on a general form of the corresponding difference equation. The numerical truncation errors are defined using Peclet and Courant numbers in the X and Y direction, a sink/source dimensionless number and new Peclet and Courant numbers in the XY plane. The effects of these truncation errors on the explicit solution of a two-dimensional advection-dispersion equation with a first-order reaction or degradation are demonstrated by comparison with an analytical solution in... 

    Modified CMC.2. Novel carboxymethylcellulose-based poly (amidoxime) chelating resin with high metal sorbtion capacities [electronic resource]

    , Article Reactive and Functional Polymers ; Volume 61, Issue 1, August 2004, Pages 23–31 Zohurian Mehr, M. J. (Mohammad Jalal) ; Pourjavadi, A ; Sadeghi, M ; Sharif University of Technology
    Abstract
    Carboxymethylcellulose sodium salt (CMC) was doubly modified to prepare a novel poly(acrylamidoxime) chelating resin. Acrylonitrile was firstly graft polymerized onto CMC using cerium ammonium nitrate as an initiator. The polyacrylonitrile (PAN) grafted CMC was then amidoximized via treatment with hydroxylamine to prepare the ion exchange resin. The sorption capacity of the resin towards bivalent metal ions was evaluated while varying the pH, the loading of the PAN and the initial metal ion concentration. The adsorption kinetics were investigated for the cupric ion. The chelating resin exhibited very high metal sorption capacity in comparison with either synthetic or polysaccharide-based... 

    Removal of toxic heavy metal ions from waste water by functionalized magnetic core–zeolitic shell nanocomposites as adsorbents

    , Article Environmental Science and Pollution Research ; Volume 20, Issue 6 , June , 2013 , pp. 3900-3909 ; 1614-7499 Padervand, M. (Mohsen) ; Gholami, M. R. (Mohammad Reza) ; Sharif University of Technology
    Abstract
    Functionalized magnetic core–zeolitic shell nanocomposites were prepared via hydrothermal and precipitation methods. The products were characterized by vibrating sample magnetometer, X-ray powder diffraction, Fourier transform infrared spectroscopy, nitrogen adsorption–desorption isotherms, and transmission electron microscopy analysis. The growth of mordenite nanocrystals on the outer surface of silica-coated magnetic nanoparticles at the presence of organic templates was well approved. The removal performance and the selectivity of mixed metal ions (Pb2+ and Cd2+) in aqueous solution were investigated via the sorption process. The batch method was employed to study the sorption kinetic,... 

    Fluoride ions removal using yttrium alginate biocomposite from an aqueous solution

    , Article International Journal of Engineering, Transactions A: Basics ; Volume 30, Issue 1 , 2017 , Pages 1-6 ; 17281431 (ISSN) Kosari, M ; Sepehrian, H ; Sharif University of Technology
    Materials and Energy Research Center  2017
    Abstract
    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... 

    Modified CMC. 2. Novel carboxymethylcellulose-based poly(amidoxime) chelating resin with high metal sorption capacity

    , Article Reactive and Functional Polymers ; Volume 61, Issue 1 , 2004 , Pages 23-31 ; 13815148 (ISSN) Zohuriaan Mehr, M. J ; Pourjavadi, A ; Salehi Rad, M ; Sharif University of Technology
    2004
    Abstract
    Carboxymethylcellulose sodium salt (CMC) was doubly modified to prepare a novel poly(acrylamidoxime) chelating resin. Acrylonitrile was firstly graft polymerized onto CMC using cerium ammonium nitrate as an initiator. The polyacrylonitrile (PAN) grafted CMC was then amidoximized via treatment with hydroxylamine to prepare the ion exchange resin. The sorption capacity of the resin towards bivalent metal ions was evaluated while varying the pH, the loading of the PAN and the initial metal ion concentration. The adsorption kinetics were investigated for the cupric ion. The chelating resin exhibited very high metal sorption capacity in comparison with either synthetic or polysaccharide-based... 

    Equilibrium sorption of crude oil by expanded perlite using different adsorption isotherms at 298.15 k

    , Article International Journal of Environmental Science and Technology ; Volume 7, Issue 3 , June , 2010 , Pages 591-598 ; 17351472 (ISSN) Alihosseini, A ; Taghikhani, V ; Safekordi, A. A ; Bastani, D ; Sharif University of Technology
    2010
    Abstract
    During the past decades, a significant increase occurred in accidental oil spill in the aquatic environments. In this regard, oil spill in Marine freshwater is still considered as a major environmental hazard. In this research, the experimental data on the sorption capacity of expanded perlite to crude oil were correlated with the equilibrium isotherm of Langmuir, Freudlich, Tempkin and the three parameter Redlich-Peterson isotherms. The results obtained from each specified isotherms were compared and accuracy of the models were favorably discussed. Accuracy of each model using the error function were evaluated. Moreover, the effect of type of objective function on the final results was... 

    New hybrid nanocomposite of copper terephthalate MOF-graphene oxide: synthesis, characterization and application as adsorbents for toxic metal ion removal from Sungun acid mine drainage

    , Article Environmental Science and Pollution Research ; Volume 24, Issue 28 , 2017 , Pages 22353-22360 ; 09441344 (ISSN) Rahimi, E ; Mohaghegh, N ; Sharif University of Technology
    Abstract
    The application of a hybrid Cu(tpa).GO (Cu(tpa) copper terephthalate metal organic framework, GO graphene oxide) composite as a new adsorbent for the removal of toxic metal ions was reported. New hybrid nanocomposite with excellent dispersibility and stability was successfully fabricated by the simple and effective ultrasonication method. The synthesized composite was characterized by scanning electron microscopy (SEM), UV-Vis and Fourier-transform infrared (FT-IR) techniques. The characterization results concluded that the binding mechanism of the Cu(tpa) and GO was related to both packing and hydrogen bonding. For scrutinizing the sorption activity, the prepared adsorbents were assessed... 

    Study of oil sorption by expanded perlite at 298.15 K

    , Article Separation and Purification Technology ; Volume 52, Issue 2 , 2006 , Pages 295-300 ; 13835866 (ISSN) Bastani, D ; Safekordi, A. A ; Alihosseini, A ; Taghikhani, V ; Sharif University of Technology
    2006
    Abstract
    Sorption capacity as well as sorption kinetics of oil onto four different expanded perlites with different physical and surface properties were studied. In order to meticulously measure the amount of oil to be sorbed onto the adsorbents used in this study both static and dynamic methods were employed. It would be worth noting that the adsorbent, i.e., perlite can spread on the oil and float on the surface thanks to its low density. The variation of the amount of oil sorbed onto the adsorbents with time was recorded and the weight of adsorbent was monitored at each specified time. The experimental results showed that grain sizes with high surface area can sorb oil to be spread on water... 

    Comparative study of conventional steam-methane-reforming (SMR) and auto-thermal-reforming (ATR) with their hybrid sorption enhanced (SE-SMR & SE-ATR) and environmentally benign process models for the hydrogen production

    , Article Fuel ; Volume 297 , 2021 ; 00162361 (ISSN) Faheem, H. H ; Tanveer, H. U ; Abbas, S. Z ; Maqbool, F ; Sharif University of Technology
    Elsevier Ltd  2021
    Abstract
    The paper presents a comparison of steam methane reforming (SMR), sorption enhanced steam methane reforming (SE-SMR), auto-thermal reforming (ATR), and sorption enhanced auto-thermal reforming (SE-ATR) in a fixed bed reformer for hydrogen production. A one-dimensional, unsteady-state heterogeneous reactor model for each process which includes mass and thermal dispersion in the direction of flow and axial pressure distribution, has been simulated using gPROMS® 4.0.1 model builder, while CEA and Aspen Plus® have been employed to analyze the equilibrium performance and simulate the process flowsheets of individual process respectively. The performance of the individual hydrogen production... 

    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
    Abstract
    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... 

    Modified CMC. 3. Carboxymethylcellulose-g-poly(acrylamidrazone) as a new metal adsorbent

    , Article Journal of Polymer Materials ; Volume 21, Issue 3 , 2004 , Pages 315-320 ; 09738622 (ISSN) Zohuriaan Mehr, M. J ; Pourjavadi, A ; Salehi Rad, M ; Sharif University of Technology
    2004
    Abstract
    A new poly(acrylamidrazone) chelating resin was prepared from carboxymethylcellulose (CMC) via a two-step process. First, acrylonitrile was graft polymerized onto the substrate. The CMC-polyacrylonitrile graft copolymer was then treated with hydrazine to yield a triply modified cellulose containing amidrazone functional groups. The resin was characterized using infrared spectroscopy. The sorption capacity of the resin towards bivalent metal ions was evaluated versus variation of pH and hydrochloric acid concentration. The adsorption capacities at pH 6 were found to be in order Cu2+> Zn2+>Cd2+>Co2+>Ni2+. The metal ion sorption capacities were varied in the range of 2.0-20.0 mmol metal per... 

    Dynamics of rear stagnant cap formation at the surface of rising bubbles in surfactant solutions at large reynolds and marangoni numbers and for slow sorption kinetics

    , Article Colloids and Surfaces A: Physicochemical and Engineering Aspects ; Volume 492 , 2016 , Pages 127-137 ; 09277757 (ISSN) Dukhin, S. S ; Lotfi, M ; Kovalchuk, V. I ; Bastani, D ; Miller, R ; Sharif University of Technology
    Elsevier  2016
    Abstract
    In spite of the high level in the theory of steady rear stagnant caps (RSC) and its influence on steady rising, its practical application is mostly impossible because the coefficients for the adsorption and desorption rates are separately unknown. The determination of ka and kd separately is an actual task for the adsorption dynamics as whole. While steady RSC and steady rising retardation by surfactants are described in literature in details, only few papers are devoted to the modeling of the decelerated rising. Moreover, steady rising depends on the ratio ka/kd and its investigation is not helpful for the determination of kd. In contrast a possibility to determine kd (or ka independently)... 

    Removal of Radioactive Elements from Liquid Waste of Bushehr Nuclear Power Plant with Resin

    , M.Sc. Thesis Sharif University of Technology Dashtinejad , Maryam (Author) ; Samadfam, Mohammad (Supervisor) ; Sepehrian, Hamid (Supervisor) ; Fasihi, Javad ($item.subfieldsMap.e)
    Abstract
    In this study, granular activated carbon has been modified by potassium nickel hexacyanoferrate ( KNCF), sodium dodecyl sulfate(SDS) and ammonium per sulfate(APS) as new adsorbents for cesium, cobalt and chromium(VI), respectively. The prepared adsorbents were characterized using powder X-ray diffraction(XRD), nitrogen adsorption-desorption isotherm data, infrared spectroscopy, scanning electron microscopy coupled with energy dispersive spectroscopy(SEM-EDS) and their adsorption performance were investigated. The effect of various parameters like the initial pH value of the solution, contact time, temperature, strength ionic of the solution, interference ions and the initial concentration of... 

    Removal of Cr(VI) by modified brown algae Sargassum bevanom from aqueous solution and industrial wastewater

    , Article Journal of the Taiwan Institute of Chemical Engineers ; Volume 44, Issue 6 , 2013 , Pages 977-989 ; 18761070 (ISSN) Javadian, H ; Ahmadi, M ; Ghiasvand, M ; Kahrizi, S ; Katal, R ; Sharif University of Technology
    2013
    Abstract
    The aim of this research work is to investigate sorption characteristic of acid treated brown algae Sargassum bevanom (acid treated S. bevanom) for the removal of Cr(VI) ions from aqueous solutions. The acid-treated alga was prepared by transferring the S. bevanom into 0.5. M HCl and then stirring the mixture at 300. rpm for 6. h at room temperature. The sorption of Cr(VI) ions by batch method is carried out. The optimum conditions of biosorption were found to be: a biomass dose of 0.7. g in 100. ml of Cr(VI), contact time of 110. min and pH 3, respectively. In optimum condition, removal efficiency was 89.64%. It was found that temperature has a positive effect on the removal efficiency.... 

    An Fe3O4@SiO2@polypyrrole magnetic nanocomposite for the extraction and preconcentration of Cd(ii) and Ni(ii)

    , Article Analytical Methods ; Volume 7, Issue 1 , Nov , 2015 , Pages 313-320 ; 17599660 (ISSN) Abolhasani, J ; Hosseinzadeh Khanmiri, R ; Ghorbani Kalhor, E ; Hassanpour, A ; Asgharinezhad, A. A ; Shekari, N ; Fathi, A ; Sharif University of Technology
    Royal Society of Chemistry  2015
    Abstract
    This work describes a novel Fe3O4@SiO2@polypyrrole magnetic nanocomposite and its application in the preconcentration of Cd(ii) and Ni(ii) ions. The parameters affecting the preconcentration procedure were optimised by a Box-Behnken design using response surface methodology. Three variables (extraction time, magnetic sorbent amount, and pH) were selected as the main factors affecting the sorption step, while four variables (type, volume and concentration of the eluent, and elution time) were selected as the main factors in the optimisation study of the elution step. Following the sorption and elution of analytes, the ions were quantified by FAAS. The limits of detection were 0.3 and 1.2 ng... 

    Novel utilization of zeolited fly ash hosting cobalt nanoparticles as a catalyst applied to the Fischer-Tropsch synthesis

    , Article Catalysis Letters ; Volume 127, Issue 1-2 , 2009 , Pages 204-212 ; 1011372X (ISSN) Fotovat, F ; Kazemeini, M ; Kazemian, H ; Sharif University of Technology
    Abstract
    In order to produce an inexpensive catalyst for the Fischer-Tropsch synthesis (FTS), zeolitized high silicon fly ash utilized as a catalytic support for cobalt nanoparticles. The ability of this new support in proper hosting of nanoparticles studied through various characterization methods such as X-ray diffraction, nitrogen sorption, transmission electron microscopy, energy-dispersive spectroscopic and temperature-programmed reduction. In addition, the catalytic properties for the FTS evaluated at 523 K and 20 MPa. The obtained results show remarkable influence of utilized support specifications upon the formation and catalytic behavior of cobalt nanoparticles in the FTS  

    Modeling of sorption enhanced steam methane reforming in an adiabatic packed bed reactor using various CO2 sorbents

    , Article Journal of Environmental Chemical Engineering ; Volume 9, Issue 5 , 2021 ; 22133437 (ISSN) Shahid, M. M ; Abbas, S. Z ; Maqbool, F ; Ramirez Solis, S ; Dupont, V ; Mahmud, T ; Sharif University of Technology
    Elsevier Ltd  2021
    Abstract
    A 1-D heterogeneous model of sorption-enhanced steam methane reforming (SE-SMR) process in a packed bed reactor consisting of nickel catalyst well mixed with CO2 sorbent particles is investigated for three types of common sorbents. The performance of SE-SMR process is studied under low medium pressure conditions (3 – 11 bar) to find the optimum operating conditions. Optimal CaO sorption corresponding to 82% CH4 conversion and 85% H2 purity is found at 900 K, 3 bar, 3.5 kgm−2s−1 and S/C of 3.0. In contrast, lithium zirconate (LZC) and hydrotalcite (HTC) sorbents exhibited best sorptions under the operating conditions of 773 K, 5 bar and S/C of 3 with CH4 conversion of 91.3% and 55.2%, and H2... 

    Hydrogen electrosorption on TiHg alloy in acidic solution

    , Article Journal of Alloys and Compounds ; Volume 432, Issue 1-2 , 2007 , Pages 74-80 ; 09258388 (ISSN) Jafarian, M ; Azizi, O ; Gobal, F ; Mahjani, M. G ; Sharif University of Technology
    2007
    Abstract
    Hydrogen evolution and electrosorption on/in TiHg alloy have been investigated in acidic solution using cyclic voltammetry, open circuit potential transient, steady-state polarization, chronopotentiometry and electrochemical impedance measurements. Comparison has been made with pure Ti. Cyclic voltammetry and open circuit potential measurements show that hydrogen absorption into the electrode material occurs during proton discharge. The steady-state polarization curves in the course of positive and negative potential scans illustrate that the formation of absorbed hydrogen slightly improves the electrocatalytic properties of the electrode. The hydrogen diffusion coefficient into the bulk of...