2022-04-122022-04-122012-06Kara, A. ve Demirbel, E. (2012). "Kinetic, isotherm and thermodynamic analysis on adsorption of Cr(VI) ions from aqueous solutions by synthesis and characterization of magnetic-poly(divinylbenzene-vinylimidazole) microbeads". Water Air & Soil Pollution, 223(5), 2387-2403.0049-69791573-2932https://doi.org/10.1007/s11270-011-1032-1https://link.springer.com/article/10.1007/s11270-011-1032-1http://hdl.handle.net/11452/25715The magnetic-poly(divinylbenzene-1-vinylimidazole) [m-poly(DVB-VIM)] microbeads (average diameter 53-212 mu m) were synthesized and characterized; their use as adsorbent in removal of Cr(VI) ions from aqueous solutions was investigated. The m-poly(DVB-VIM) microbeads were prepared by copolymerizing of divinylbenzene (DVB) with 1-vinylimidazole (VIM). The m-poly(DVB-VIM) microbeads were characterized by N-2 adsorption/desorption isotherms, ESR, elemental analysis, scanning electron microscope (SEM) and swelling studies. At fixed solid/solution ratio the various factors affecting adsorption of Cr(VI) ions from aqueous solutions such as pH, initial concentration, contact time and temperature were analyzed. Langmuir, Freundlich and Dubinin-Radushkvich isotherms were used as the model adsorption equilibrium data. Langmuir isotherm model was the most adequate. The pseudo-first-order, pseudo-second-order, Ritch-second-order and intraparticle diffusion models were used to describe the adsorption kinetics. The apparent activation energy was found to be 5.024 kJ mol(-1), which is characteristic of a chemically controlled reaction. The experimental data fitted to pseudo-second-order kinetic. The study of temperature effect was quantified by calculating various thermodynamic parameters such as Gibbs free energy, enthalpy and entropy changes. The thermodynamic parameters obtained indicated the endothermic nature of adsorption of Cr(VI) ions. Morever, after the use in adsorption, the m-poly(DVB-VIM) microbeads with paramagnetic property were separeted via the applied magnetic force. The magnetic beads could be desorbed up to about 97% by treating with 1.0 M NaOH. These features make the m-poly(DVB-VIM) microbeads a potential candidate for support of Cr(VI) ions removal under magnetic field.eninfo:eu-repo/semantics/openAccessEnvironmental sciences & ecologyMeteorology & atmospheric sciencesWater resourcesMagnetic polymersAdsorption isothermAdsorption kineticAdsorption thermodynamicCr (VI) ionsHeavy-metal ionsWaste-waterActivated carbonHexavalent chromiumMagnetic beadsRemovalSorptionBiosorptionAdsorbentChitosanChromium compoundsDesorptionDyesIonsKineticsMagnetic fieldsParamagnetismPolymethyl methacrylatesScanning electron microscopySynthesis (chemical)ThermoanalysisThermodynamicsAdsorption equilibriaAdsorption kineticsAdsorption thermodynamicsAdsorption/desorptionApparent activation energyAverage diameterContact timeControlled reactionsEndothermic natureEntropy changesExperimental dataFreundlichInitial concentrationIntraparticle diffusion modelsLangmuir isotherm modelsLangmuirsMagnetic beadsMagnetic forceMagnetic polymersMicrobeadsParamagnetic propertiesPseudo second order kineticsSolid/solution ratioSwelling studiesThermo dynamic analysisThermodynamic parameterAdsorptionAqueous solutionBenzeneChromiumIsothermPolymerRemoval experimentTemperatureThermodynamicsZincArticle0003044670000382-s2.0-8486221879623872403223522707803Environmental sciencesMeteorology & atmospheric sciencesWater resourcesChromium Hexavalent Ion; Biosorbents; Second-Order ModelChromiumCopolymerPoly(divinylbenzene 1 vinylimidazole)Sodium hydroxideUnclassified drugAdsorptionAqueous solutionArticleChemical reactionConcentration (parameters)DesorptionDiffusionElectron spin resonanceEnthalpyEntropyHeavy metal removalIsothermKineticsMagnetic fieldMagnetismPhPolymerizationScanning electron microscopySynthesisTemperatureThermodynamics