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Öğe Adsorption Characteristics of Heavy Metal İons Onto a Low Cost Biopolymeric Sorbent From Aqueous Solutions(Elsevier, 2006) Ünlü, Nuri; Ersöz, MustafaIn this study, the adsorption conditions of Cu(II), Pb(II) and Cd(II) metal ions onto sporopollenin have been studied. The different variables effecting the sorption capacity such as pH of the solution, adsorption time, initial metal ion concentration and temperature have been investigated. Adsorption isotherms correlated well with the Freundlich type adsorption isotherm and adsorption capacities were found to be 0.0195, 0.0411 and 0.0146 mmol g(-1) for Cu(II), Pb(II) and Cd(II) metal ions, respectively. Experimental data were also evaluated to find out kinetic characteristics of the adsorption process. Adsorption processes for three target heavy metal ions were found to follow pseudo-second order type adsorption kinetics. Intraparticle diffusion was found to take part in adsorption processes but it could not be accepted as the primary rate-determining step. The mean free energies of adsorption (E) were found to be between 8 and 16 kJ mol(-1) for the metal ions studied and therefore adsorption mechanism for the adsorbent was explained as an ion-exchange process. But it was observed that chelating effect is also playing an important role in the adsorption of metal ions onto sporopollenin. Thermodynamic parameters, Delta H degrees, Delta S degrees and Delta G degrees were also calculated from graphical interpretation of the experimental data. Standard heats of adsorption (Delta H degrees) were found to be endothermic and AS' values were calculated to be positive for the adsorption of Cu(II), Pb(II) and Cd(II) ions onto the adsorbent. Negative Delta G degrees values indicated that adsorption process for these three metal ions onto sporopollenin is spontaneous.Öğe Bazı toksit metallerin fonksiyonel gurup bağlanmış sporopellenin üzerine adsorpsiyonu ve termodinamik özelliklerin incelenmesi(Selçuk Üniversitesi Fen Bilimleri Enstitüsü, 2004-09-17) Ünlü, Nuri; Ersöz, Mustafa; TR126791Bu çalışmada sporopolleninin kimyasal modifikasyonla ksantat bağlı Ksantat S poropollenin ( Ksan-Sp) v e D ietilditiyokarbamat S poropollenin (DTC-Sp) formları hazırlanmıştır. Hazırlanmış olan bu adsorbanlar üzerine Cu (II), Pb (II) ve Cd (II) metal iyonlarının adsorpsiyon şartları optimize edilmiştir. Deneysel sonuçlar kullanılarak kinetik değerlendirmeler yapılmış ve adsorpsiyona ilişkin termodinamik parametreler tespit edilmiştir. Cu (II), Pb (II) ve Cd (Il)'nin sporopollenine adsorpsiyonlannm Freundlich tipi adsoprsiyon izotermine; Ksan-Sp ve DTC-Sp'nin ise Langmuir tipi adsorpsiyon izotermine uygunluk gösterdiği görülmüş ve Ksan-Sp ve DTC-Sp'nin Sporopollenine göre adsorpsiyon kapasitelerinin çok yüksek olduğu tespit edilmiştir. Sporopollenin, Ksan-Sp ve DTC-Sp'ye Cu (II), Pb (II) ve Cd (Il)'nin adsoprsiyonlarının 2. dereceden adsorpsiyon kinetiğine uygunluk gösterdiği görülmüştür. Ayrıca parçacık içi difüzyonun adsorpsiyona etki ettiği ancak hız belirleyen basamak olmadığı anlaşılmıştır. Her üç adsorbanda da adsorpsiyon mekanizması iyon değişim reaksiyonuyla açıklanmıştır. Adsorpsiyonda her üç adsorbanın da şelatlaştırıcı etkilerinin adsorpsiyona katkıda bulunduğu görülmüştür. Her üç adsorban içinde termodinamik parametreler tespit edilmiş adsorpsiyona ilişkin AH0, AS0 ve AG° değerleri hesaplanmıştır. Elde edilen sonuçlardan Cu (II), Pb (II) ve Cd (Il)'nin sporopollenin, Ksan-Sp ve DTC-Sp'ye adsorpsiyonlannm endodermik ve kendiliğinden olduğu tespit edilmiştir. Ayrıca AS0 değerlerinin pozitif olduğu görülmüştür.Öğe Glycine Transport Through a Charged Polysulfone Cation Exchange Membrane(Scientific Technical Research Council Turkey, 2002) Ünlü, Nuri; Kara, Hüseyin; Ersöz, MustafaThe transport of glycine through a charged polysulfone cation exchange membrane was studied as a function of pH at different initial conditions of less than pH 5.9 and the glycine permeability was explained under the experimental conditions as pH dependent interfacial transport. The glycine permeability increases with a decreasing pH in the receiver phase. The largest permeability was obtained if the initial pH oil the source side was pH 5.9 and that oil the opposite side was pH 2.0. The transport phenomena can be explained by the interfacial transport based on the interfacial chemical reaction (protonation, deprotonation or ion-exchange) between both phases in terms of the initial pH of the solution.Öğe Removal of heavy metal ions by using dithiocarbamated-sporopollenin(ELSEVIER, 2007) Ünlü, Nuri; Ersöz, MustafaIn this study, the sorption conditions of Cu(II), Pb(II) and Cd(II) metal ions onto dithiocarbamated-spororpollenin (DTC-S) have been investigated. The different variables affecting the sorption capacity such as pH of the solution, sorption time, initial metal ion concentration and temperature have been investigated. Experimental data were exploited for kinetic and thermodynamic evaluations related to the sorption processes. Sorption isotherms correlated well with the Langmuir type sorption isotherm and sorption capacities were found to be 0.2734, 0.4572 and 0.0631 mmol g(-1) for Cu(II), Pb(II) and Cd(II) metal ions, respectively. Sorption processes for three target heavy metal ions were found to follow pseudo-second order type sorption kinetics. Intraparticle diffusion was found to take part in sorption processes but it could not be accepted as the primary rate determining step. On the evaluation of the results obtained for the mean free energies of sorption (E) and enthalpy of sorption (Delta H degrees) it was observed that the resin mainly shows the characteristics of a chelating exchanger. Thermodynamic parameters, Delta H degrees, Delta S degrees and Delta G degrees were also calculated from graphical interpretation of the experimental data. Standard heats of sorption (Delta H degrees) were found to be endothermic and Delta S degrees values were calculated to be positive for the sorption of Cu(II), Pb(II) and Cd(II) ions onto the adsorbent. Negative Delta G degrees values indicated that sorption process for these three metal ions onto DTC-Sp is spontaneous. (c) 2006 Elsevier B.V. All rights reserved.
