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Öğe Adsorption of phenol from aqueous solution on a low-cost activated carbon produced from tea industry waste: Equilibrium, kinetic, and thermodynamic study(American Chemical Society, 2012) Gundogdu A.; Duran C.; Senturk H.B.; Soylak M.; Ozdes D.; Serencam H.; Imamoglu M.The ability of activated carbon which was produced by chemical activation using zinc chloride from tea industry wastes (TIWAC) to adsorb phenol molecules from aqueous solution was tested by equilibrium, kinetic, and thermodynamic parameters. Phenol adsorption on TIWAC took place with a high yield at pH values in the range 4 to 8. The optimum contact period was observed as 4.0 h and from the adsorption graphs plotted as a function of time; it was established that phenol adsorption on TIWAC conformed more to a pseudosecond-order kinetic model. Additionally, it was determined that the adsorption rate is controlled by intraparticle diffusion as well as film diffusion. It was established that phenol adsorption on TIWAC can be better defined by the Langmuir adsorption model and its adsorption capacity was 142.9 mg·g-1 from the linear Langmuir equation. Temperature had an adverse effect on adsorption yield, and hence, the adsorption process was exothermic in our case. Moreover, increasing electrolyte concentration in the medium has a positive effect on adsorption yield. From the data obtained, it was concluded that the removal of phenol from aqueous solution by TIWAC produced from tea industry wastes with a very low cost took place with an extremely high performance. © 2012 American Chemical Society.Öğe Application of carrier element free coprecipitation (CEFC) method for determination of Co(II), Cu(II) and Ni(II) ions in food and water samples(2013) Serencam H.; Duran C.; Ozdes D.; Bektas H.A simple and highly sensitive separation and preconcentration procedure, which has minimal impact on the environment, has been developed. The procedure is based on the carrier element free coprecipitation (CEFC) of Co(II), Cu(II), and Ni(II) ions by using 2-{4-[2-(1H-indol-3-yl)ethyl]-3-(4-methylbenzyl)-5-oxo- 4,5-dihydro-1H-1,2,4-triazol- 1-yl}-N'-(pyridin-2-yl methylidene)acetohydrazide (IMOTPA), as an organic coprecipitant. The levels of analyte ions were determined by flame atomic absorption spectrometry (FAAS). The detection limits for Co(II), Cu(II) and Ni(II) ions were found to be 0.40, 0.16 and 0.17 ?g L-1, respectively, and the relative standard deviations for the analyte ions were lower than 3.0%. Spike tests and certified reference material analyses were performed to validate the method. The method was successfully applied for the determination of Co(II), Cu(II) and Ni(II) ions levels in sea and stream water as liquid samples and red pepper, black pepper, and peppermint as solid samples.Öğe Assessment of kinetics, thermodynamics, and equilibrium parameters of Cu(II) adsorption onto Rosa canina seeds(Taylor and Francis Inc., 2014) Serencam H.; Ozdes D.; Duran C.; Senturk H.B.Rosa canina seeds (RCS) is considered as a low-cost and promising adsorbent in removal of metal ions; hence, in the present study, we aimed to test the adsorptive removal of Cu(II) ions from aqueous solutions by utilizing RCS in a batch process. After characterization of RCS by using several techniques, the effects of various experimental parameters such as initial pH of aqueous solution, contact time, initial Cu(II) concentration, RCS concentration, temperature, and electrolyte concentration were studied upon the adsorption process. The desorption conditions of Cu(II) ions from the loaded RCS were also evaluated. Maximum Cu(II) adsorption was found to occur at pH 6.0 and the equilibrium was established after 60 min of contact time. The adsorption isotherms were described by means of Langmuir, Freundlich, Temkin, and Dubinin Radushkevich models. The adsorption kinetics were analyzed using pseudo-first-order, pseudo-second-order, Elovich and intraparticle diffusion models and the adsorption data were well described by the pseudo-second-order model. Thermodynamic parameters such as the Gibbs free energy (?G), enthalpy (?H), and entropy (?S) changes were also evaluated and it has been found that the adsorption process was feasible, spontaneous, and endothermic in the temperature range of 278-313 K. © 2013 Balaban Desalination Publications. All rights reserved.Öğe Biosorption properties of Morus alba L. for Cd (II) ions removal from aqueous solutions(2013) Serencam H.; Ozdes D.; Duran C.; Tufekci M.The abundantly available industrial waste product Morus alba L. pomace (MAP) is one of the cost-effective biosorbent for removal of metal ions from aqueous solutions. Hence, in the present study, we aimed to test the ability of MAP to remove Cd(II) ions through batch biosorption process. Firstly, MAP was characterized using several techniques, and then the influence of various experimental parameters such as initial pH of the aqueous solution, initial Cd(II) concentration, contact time, MAP concentration, and temperature were evaluated upon the biosorption process. It was found that the maximum uptake of Cd(II) ions occurred at initial pH 6.0 and optimum contact time was observed as 60 min. Cd(II) ions adsorption on MAP analyzed by the Langmuir and Freundlich isotherm models and the maximum monolayer biosorption capacity of MAP was found to be 21.69 mg g -1 by using the Langmuir isotherm model. The pseudo-first-order, pseudo-second-order, Elovich, and intraparticle diffusion models were employed to describe the biosorption kinetics. In order to investigate the thermodynamic properties of the biosorption process, the changes in the Gibbs free energy (â?†G), enthalpy (â?†H), and entropy (â?†S) were also evaluated and it has been concluded that the process was feasible, spontaneous, and endothermic in the temperature range of 5-40 C. © 2012 Springer Science+Business Media Dordrecht.Öğe Selective separation, preconcentration and determination of Pd(II) ions in environmental samples by coprecipitation with a 1,2,4-triazole derivative(Chemical Society of Ethiopia, 2015) Ozdes D.; Duran C.; Serencam H.; Sahin D.; Gundogdu A.; Soylak M.A simple, sensitive, facile and low cost methodology, combined with flame atomic absorption spectrometry (FAAS), was employed to evaluate the selective separation and preconcentration of Pd(II) ions in environmental samples by using a triazole derivative as an organic coprecipitating agent without a carrier element. The developed method was systematically investigated in different set of experimental parameters that influence the quantitative recovery of Pd(II) ions. The accuracy of the method was tested by analyzing certified reference material and spike tests. The developed coprecipitation procedure has been applied to road dust, anodic slime, industrial electronic waste materials and water samples to determine their Pd(II) levels. © 2015 Chemical Society of EthiopiaÖğe Selective Separation, Preconcentration, and Determination of Au (III) Ions in Environmental Samples by Coprecipitation With a 1,2,4-Triazole Derivative(2013) Ozdes D.; Duran C.; Serencam H.; Şahin D.An effective, simple, lowcost, and accurate separation and preconcentration procedure which has minimal impact on the environment has been developed. It is based on the carrier element-free coprecipitation (CEFC) of Au(III)ions using N-benzyl-2-{[3-methyl-4-(2morpholine-4-ylethyl)-5-oxo-4,5-dihydro-1H-1,2, 4-triazole-1-yl] acetyl)hydrazinecarboxamide (BODAH) as an organic coprecipitant. Determination of the Au(IH) ion levels was performed by flame atomic absorption spectrometry (FAAS). The developed method provided a detection limit of 0.36 ?g L-1 and the relative standard deviation for Au(III)ions was found to be 5.1%. Spike tests and certified reference material analyses were performed to validate the method. The developed method was systematically investigated in different sets of experimental parameters that influence the quantitative recovery of the Au(III)ions. Based on these investigations, the optimum conditions for the determination of Au(III) ions at trace levels were established. The coprecipitation method was applied to anodic slime, gold ore, soil, and water samples to determine their Au(III)levels.Öğe Simultaneous separation and preconcentration of Cd(II), Co(II), and Ni(II) ions in environmental samples by carrier element-free coprecipitation method prior to their flame atomic absorption spectrometric determination(Taylor and Francis Inc., 2015) Duran C.; Ozdes D.; Akcay H.T.; Serencam H.; Tufekci M.ABSTRACT: In the present study, Cd(II), Co(II), and Ni(II) ions were separated and preconcentrated via carrier element-free coprecipitation (CEFC) method by using an organic coprecipitating agent, 1,2-bis-(2-tosyl ethoxy) benzene (BTEB), prior to their flame atomic absorption spectrometric (FAAS) detections. The experimental conditions were optimized in terms of pH of the aqueous solution, BTEB amount, standing time, centrifugation rate and time, and sample volume. Under the optimum experimental conditions, the detection limits for Cd(II), Co(II), and Ni(II) ions were found to be 0.13, 0.67, and 0.46 ?g L?1, respectively, and the relative standard deviations for the analyte ions were found to be lower than 4.0%. The accuracy of the method was tested by analyzing certified reference material and spike tests. The method was applied to determine the levels of Cd(II), Co(II), and Ni(II) ions in sea and stream water, macaroni, red lentil, and cracked wheat samples. © 2013, © 2013 Balaban Desalination Publications. All rights reserved.Öğe Simultaneous separation and preconcentration of Ni(II) and Cu(II) ions by coprecipitation without any carrier element in some food and water samples(Blackwell Publishing Ltd, 2014) Duran C.; Tumay S.O.; Ozdes D.; Serencam H.; Bektas H.A simple and highly sensitive separation and preconcentration procedure, which has minimal impact on the environment, has been developed. The procedure is based on the carrier element-free coprecipitation of Ni(II) and Cu(II) ions by using 2-{4-[2-(1H-Indol-3-yl)ethyl]-3-(4-chlorobenzyl)-5-oxo-4,5-dihydro-1H-1,2,4-triazol-1-yl}-N?-(pyrrol-2-ylmethyliden)acetohydrazide (ICOTPA), as an organic coprecipitant. The levels of analyte ions were determined by flame atomic absorption spectrometry. The detection limits for Ni(II) and Cu(II) ions were found to be 0.27 and 0.58 ?g L-1, respectively, and the relative standard deviations for the analyte ions were lower than 4.0%. Spike tests and certified reference material analyses were performed to validate the method. The method was successfully applied for the determination of Ni(II) and Cu(II) ions levels in sea and stream water as liquid samples and red lentil and rice as solid samples. © 2013 Institute of Food Science and Technology.Öğe Solid phase extraction of Cd(ii) and pb(ii) ions by a new carbothioamide derivative(Sociedad Chilena de Quimica, 2013) Ozdes D.; Duran C.; Bayrak H.; Serencam H.; Basri Senturk H.An effective, simple, low cost and accurate sorption-spectrophotometric platform for the extractions and subsequent quantifications of Cd(II) and Pb(II) ions in food and environmental samples has been described in this dissertation. The separation and preconcentration of the analyte ions were accomplished by solid phase extraction method based on the adsorption of their N-(4-methylphenyl)-2-{[(4-phenyl-5-pyridin-4-yl-4H-1,2,4-triazol-3-yl)thio] acetyl} hydrazinecarbothioamide (MFPTAHK) complex on Amberlite XAD-8 resin in a mini column. The developed method was systematically investigated in different set of experimental parameters that influence the separation and preconcentration of Cd(II) and Pb(II) ions. The precision of the method was determined by reproducibility studies and expressed as relative standard deviations (RSD %) which were less than 4% for both analyte ions. The limits of detections (LODs) for Cd(II) and Pb(II) ions based on the three times the standard deviation of the blanks (N:10) were found to be 0. 31 ?g L-1 and 0. 86 ?g L-1, respectively. The developed SPE procedure was utilized for the simultaneous extraction and determinations of Cd(II) and Pb(II) ions levels in rice, cracked wheat and red lentil as food samples and various water samples.
