Multicomponent ion exchange on synthetic zeolites

Download

index.pdf

Date

2014

Author

Beşel Düzgün, Elif

Metadata

Show full item record

Item Usage Stats

181
views

108
downloads

Zeolites are natural and synthetic microporous crystalline aluminosilicates with ion-exchange and molecular sieve properties. Zeolites consist of a three-dimensional framework of (SiO4)4- and (AlO4)5- tetrahedras, connected by a shared oxygen atom. The presence of aluminum in the aluminosilicate framework introduces a net negative charge. Zeolites are mostly used in ion exchange, adsorption processes and catalytic applications. The objective of the study was to determine and model the multicomponent ion exchange behavior of Zeolite 13X for lead, cadmium and zinc ions. For this purpose, Pb2+- Na+ , Cd2+-Na+ and Zn2+ - Na binary systems, Cd2+- Pb2+ - Na+ ternary systems and Cd2+- Pb2+ - Zn2+ - Na+ quaternary systems were investigated in batch and column operations. Breakthrough capacities and column efficiencies were determined at different concentrations, mesh ranges and flow rates. Optimum total concentration were determined as 0.05 N, optimum flow rate as 10 mL/min, optimum particle size range as 0.6-0.7 mm (25/30 mesh ranges). Ion exchange of Pb2+, Cd2+ and Zn2+on to NaX zeolite was modelled using the Langmuir, Freundlich, Tempkin, DR, Redlich Peterson, Sips and BET isotherms. Among all the isotherms tested, Redlich Peterson isotherm gave the best fit for all metals with the highest R2 and lowest ARE values. The Modified Langmuir Model, Jain and Snoeyink Model, SRS Model, Extended SIPS Model and IAST Model were used to fit the multicomponent ion exchange data; but only SRS Isotherm Model was observed to fit the experimental data with high linear coefficient of determination. Pseudo-second order kinetic equation describe the batch system kinetics well. W&M model indicated that the intra-particle diffusion is not the only rate controlling step, Finally possible mass transfer controlling mechanism in the column experiments was determined as solid diffusion. Solid-phase diffusion coefficients were evaluted as 4.3x10-6 cm2/min for Pb2+- NaX exchange; 4.6x10-6 cm2/min for Cd2+- NaX exchange and 2.2x10-6 cm2/min for Zn2+- NaX exchange

Subject Keywords

Ion exchange., Zeolites., Zinc., Copper., Lead.

URI

http://etd.lib.metu.edu.tr/upload/12618201/index.pdf
https://hdl.handle.net/11511/24210

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Multiscale Modeling of the Morphology and Properties of Segmented Silicone-Urea Copolymers Yıldırım, Erol; Yurtsever, Ersin; Yilgor, Iskender; Yilgor, Emel (Springer Science and Business Media LLC, 2011-9-9) Molecular dynamics and mesoscale dynamics simulation techniques were used to investigate the effect of hydrogen bonding on the microphase separation, morphology and various physicochemical properties of segmented silicone-urea copolymers. Model silicone-urea copolymers investigated were based on the stoichiometric combinations of alpha,omega-aminopropyl terminated polydimethylsiloxane (PDMS) oligomers with number average molecular weights ranging from 700 to 15,000 g/mole and bis(4-isocyanatocyclohexyl)meth...
Covalent immobilization of chloroperoxidase onto magnetic beads: Catalytic properties and stability Bayramoglu, Guelay; Kiralp, Senem; Yilmaz, Meltem; Toppare, Levent Kamil; Arica, M. Yakup (Elsevier BV, 2008-02-15) Amino groups containing magnetic beads were used in covalent immobilization of the enzyme "chloroperoxidase (CPO)" which is one of a few enzymes that can catalyse the peroxide dependent oxidation of a wide spectrum of organic and inorganic compounds. The magnetic poly(glycidylmethacrylate-methylmethacrylate-etbyleneglycol dimethacrylate), magnetic p(GMA-MMA-EGDMA) beads were prepared via suspension polymerization in the presence of ferric ions. The magnetic beads were characterized with scanning electron mi...
Hydrogen bonding in polyanilines Bahçeci, S.; Toppare, Levent Kamil; Yurtsever, E. (Elsevier BV, 1994-12) Hydrogen bonding between poly(bisphenol A carbonate) (PC) and polyaniline (PAn) is analyzed using semi-empirical quantum methodology. Fully optimized AM1 molecular orbital calculations are reported for various aniline structures (monomer, dimer and trimer), the monomer of the PC and the hydrogen-bonded model of PAn-PC oligomer.
Multipurpose acetic acid functionalized carbazole derivatives: Synthesis, electrochemical properties and electrochromic device applications Özdemir Hacıoğlu, Şerife; YİĞİT, DENİZ; Akbey, Tuba E.; UDUM, YASEMİN; GÜLLÜ, MUSTAFA; DEPCİ, TOLGA; Toppare, Levent Kamil (2022-03-01) In this study, synthesis of two multifunctional acetic acid functionalized carbazole bearing monomers; 243,6-bis(2,3-dihydrothieno [3,4-b] [1,4]dioxin-5-yl)-9H-carbazol-9-yl)acetic acid (Ml) and 3,6-dithien-2-yl-9H car bazol-9-ylaceticacid (M2) via Stille cross-coupling reaction was reported. Obtained monomers were electro-chemically polymerized in 0.1 M TBAPF(6)/DCM/ACN (5:95, v:v) solution and characterized in terms of electrochemical, spectroelectrochemical and electrochromic switching behaviors. When po...
Synthesis of CuO nanostructures on zeolite-Y and investigation of their CO2 adsorption properties Boruban, Cansu; Nalbant Esentürk, Emren (2017-10-01) Copper(II) oxide (CuO) nanoparticles (NPs) in two different morphologies, spiky and spherical, were synthesized on zeolite-Y by a modified impregnation method, and their CO2 adsorbing capabilities were investigated under standard conditions (1 atm and 298 K). The properties and CO2 adsorption performances of the hybrid systems were characterized by transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray, X-ray diffraction, X-ray photoelectron spectroscopy, atomic absorption s...

Citation Formats

E. Beşel Düzgün, “Multicomponent ion exchange on synthetic zeolites,” Ph.D. - Doctoral Program, Middle East Technical University, 2014.