Browsing by Author "Tirtom V.N."
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Item Some heavy metal determination by ICP-OES in human scalp hair (In three different regions of Manisa); [İnsan saçında bulunan (Manisa İlinin üç farklı yerleşim bölgesinde) Bazı aǧir metallerin ICP-OES yöntemi ile tayini](Ekoloji, 2009) Çelik A.; Abali Y.; Edgünlü G.; Uzunoǧlu S.; Tirtom V.N.The aim of this study was to determine the levels of As, Cd, Mn, Cr, Fe, Pb, Hg, Zn and Se in hair samples collected from the nape of the neck of voluntary people living or working in the industrial region, city center and countryside of Manisa province. The concentrations of As, Cd, Mn, Cr, Fe, Pb, Se, Zn were determined by ICP-OES. The measured values of trace elements in human hair samples were compatible to the reference values given in the literature. The measured values of As, Hg, Cr, Cd, Se and Pb were found below the detection limit of the method. Zn, Mn and Fe were statistically analysed and evaluated. When the Fe and Mn values of the hair samples collected from the industrial region were compared with the data from both the city center and countryside (ANOVA), the differences were meaningful and significant, but the differences for Zn between the industrial region, city center and countryside were found to be insignificant.Item Arsenic and antimony determination in refined and unrefined table salts by means of hydride generation atomic absorption spectrometry-comparison of sample decomposition and determination methods(2011) Aksuner N.; Tirtom V.N.; Henden E.An evaluation was made of different digestion methods for the determination of arsenic and antimony in table salt samples prior to hydride generation atomic absorption spectrometric analysis. Microwave acid digestion, classical wet digestion, dry ashing, and fusion were applied to the decomposition of salt samples and optimum conditions were investigated. Samples were decomposed by changing heating time, digestion techniques, and the amount and composition of acid, and then the concentrations of arsenic and antimony in an unrefined salt sample were measured. It is concluded that microwave acid digestion decomposes salt samples with a very short heating time and with small amounts of reagents compared with the classical wet digestion methods, which require several hours for the heating step and several milliliters of reagents. The accuracy of the procedure was checked using pond sediment certified reference material. The proposed procedure was applied for the determination of arsenic and antimony in several table salt samples collected in I zmir, Turkey, and the arsenic contents in the samples were found to be below the maximum permissible limits. Microwave digestion in combination with hydride generation atomic absorption spectrometry could be used routinely to monitor these metals in table salt samples. © TÜBITAK.Item Arsenic removal from aqueous system using natural and modified (Kula ebonite and zeolite) adsorbents(2012) Gülbaş G.; Tirtom V.N.; Çelik A.; Dost K.Natural adsorbents (Kula ebonite, zeolite and zeolite treated with Al 2(SO4)3; Al2(SO4) 3+NaOH; FeCl3 and FeCl3+NaOH) were prepared and employed by means of batch method for selective adsorption and removal of arsenic from aqueous system. The influences of different parameters such as, contact time, pH, temperature, and concentration of adsorbate on adsorption performance of zeolite and zeolite treated with FeCl3 and FeCl 3+NaOH were studied in order to optimize the adsorption conditions. Batch adsorption studies have shown that removal capacity of zeolite from aqueous solutions can be increased by FeCl3 and FeCl3+NaOH treatment. The maximum adsorption capacities were 1.99 and 3.43 mg g -1 of zeolite which was treated with FeCl3 and FeCl 3+NaOH for arsenic, respectively. The adsorption data obtained follows a first-order rate expression and fits the Langmuir isotherm that has been used to obtain thethermodynamic parameters. In addition, the thermodynamic parameters, standard free energy (ΔG°), standard enthalpy (ΔH°), standard entropy (ΔS°) of the adsorption process were calculated. It was found that the adsorption of arsenic on zeolite was exothermic. © 2012 American Institute of Chemical Engineers.Item Comparative adsorption of Ni(II) and Cd(II) ions on epichlorohydrin crosslinked chitosan-clay composite beads in aqueous solution(2012) Tirtom V.N.; Dinçer A.; Becerik S.; Aydemir T.; Çelik A.Removal of Ni(II) and Cd(II) by adsorption on epichlorohydrin crosslinked chitosan-clay composite beads was examined in solutions representative of contaminated solutions containing heavy metals. Several important parameters influencing the adsorption of Ni(II) and Cd(II) ions such as contact time, pH, temperature and effect of metal concentration were investigated systematically by batch experiments. Langmuir and Freundlich adsorption models were used to describe adsorption isotherms and constants. The obtained results showed that the equilibrium adsorption behavior of Ni (II) and Cd (II) on epichlorohydrin crosslinked chitosan-clay composite beads could be applied to Langmuir and Freundlich models respectively. Maximum adsorption capacities for Ni(II) and Cd(II) ions were found as 32.36mgg-1 and 72.31mgg-1 respectively. The recovery of the metal ions after adsorption and the regeneration of the adsorbent was carried out by treatment of the loaded beads with either 0.1M HNO3, or 0.01M EDTA. The adsorbents were characterized by FTIR, SEM and TGA analysis. © 2012 Elsevier B.V.Item Removal of lead (II) ions from aqueous solution by using crosslinked chitosan-clay beads(Elsevier B.V., 2012) Tirtom V.N.; Dinçer A.; Becerik S.; Aydemir T.; Çelik A.Faculty of Arts and Sciences, Department of Chemistry, Celal Bayar University, 45140, Manisa Turkey Tel. +90 2362412151; Fax: +90 2362412128, +90 2362412158;A simple and effective biodegradable material known as chitosan-clay composite beads wereprepared to remove Pb(II) ions from aqueous solution. For this purpose, various importantparameters such as contact time, pH and temperature were examined on the adsorption ofPb(II) ions onto crosslinked chitosan-clay composite beads. Maximum adsorption capacity ofPb(II) was observed at pH 4.5 and 25°C and calculated as 7.93 mg/g according to Langmuirisotherm model. Thermodynamic parameters namely ΔG°, ΔH° and ΔS° of the Pb(II) adsorptionprocess have been calculated as 7.889 kJ/mol, -15.131 kJ/mol and -0.0785 kJ/molK respectively.EDTA was the best eluent for the desorption of Pb(II) ions from the crosslinked chitosan-claybeads. Scanning electron microscope (SEM) was used to characterize the surface morphologyof the crosslinked chitosan-clay beads. © 2012 Elsevier Inc.Item Removal of lead (II) ions from aqueous solution by using crosslinked chitosan-clay beads(Taylor and Francis Inc., 2012) Tirtom V.N.; Dinçer A.; Becerik S.; Aydemir T.; Çelik A.A simple and effective biodegradable material known as chitosan-clay composite beads were prepared to remove Pb(II) ions from aqueous solution. For this purpose, various important parameters such as contact time, pH and temperature were examined on the adsorption of Pb(II) ions onto crosslinked chitosan-clay composite beads. Maximum adsorption capacity of Pb(II) was observed at pH 4.5 and 25°C and calculated as 7.93 mg/g according to Langmuir isotherm model. Thermodynamic parameters namely ΔG°, ΔH° and ΔS° of the Pb(II) adsorption process have been calculated as 7.889 kJ/mol, -15.131 kJ/mol and -0.0785 kJ/molK respectively. EDTA was the best eluent for the desorption of Pb(II) ions from the crosslinked chitosan-clay beads. Scanning electron microscope (SEM) was used to characterize the surface morphology of the crosslinked chitosan-clay beads. © 2012 Desalination Publications.Item Epichlorohydrin crosslinked chitosan-clay composite beads for on-line preconcentration and determination of chromium(iii) by flow injection flame atomic absorption spectrometry(Royal Society of Chemistry, 2014) Cittan M.; Tirtom V.N.; Dinçer A.; Çelik A.An on-line flow injection preconcentration-flame atomic absorption spectrometry (FI-AAS) method is developed for trace determination of chromium(iii) by sorption on a mini-column packed with epichlorohydrin (ECH) crosslinked chitosan-clay composite beads. The factors affecting preconcentration of Cr(iii) ions such as sample and eluent flow rate, loading time, sample and eluent pH, and eluent type and concentration were investigated. The Cr(iii) ions were eluted from the mini-column with 0.1 M EDTA. Under the optimized parameters, the calibration graph using the preconcentration system for Cr(iii) was linear with a correlation coefficient of 0.9982. Detection and quantification limits of the method were obtained to be 0.0162 and 0.0929 μg mL-1 respectively, with an enrichment factor of 13.4. © 2014 The Royal Society of Chemistry.Item Iron(III) selective fluorescence probe based on perylene tetracarboxylic diimide(Maik Nauka Publishing / Springer SBM, 2014) Tirtom V.N.; Çelik-Erbaş S.; Birel O.; Xue C.Responses of organic fluorophore, perylenediimide derivative N,N'-di[3-[2-(3-thienyl)ethyl]phenyl]perylene-3,4,9,10-bis-(dicarboxyimide) (PDI1) was investigated in polymer matrix of polyvinyl chloride (PVC) by emission spectrometry. Its response to Fe(III) ions was evaluated in terms of the effect of pH. The properties of time dependent response, reversibility, limit of detection, linear concentration range for the metal ion and repeatability characteristics of the sensing element also have been studied. The offered sensor exhibited remarkable fluorescence intensity quenching at pH 6.0 in the concentration range of 1 × 10-6 to 2.5 × 10 -3 M Fe(III) ions. The reproducibility of the sensor membrane was investigated by alternately changing the solution between 1 × 10 -4 M Fe(III) in Na2HPO4 (4 × 10 -2 M) and NaH2PO4 buffer (2 × 10 -3 M). © 2014 Pleiades Publishing, Ltd.Item Arsenic removal from aqueous system using modified chestnut shell(Bellwether Publishing, Ltd., 2015) Targan Ş.; Tirtom V.N.Natural adsorbent chestnut shell treated with FeCl3 was prepared and employed by means of batch method for selective adsorption and removal of arsenic from aqueous system. The influences of different parameters, such as contact time, pH, temperature, and concentration of adsorbate, on adsorption performance of chestnut shell treated with FeCl3 was studied in order to optimize the adsorption conditions. Batch adsorption studies have shown that removal capacity of chestnut shell can be increased by FeCl3 treatment. The maximum adsorption capacity was found to be 0.885 mg g−1 As(III) of chestnut shell, which was treated with FeCl3. The adsorption data obtained follow a first-order rate expression and fit the Freundlich isotherm that has been used to obtain the thermodynamic parameters. In addition, the thermodynamic parameters, such as standard free energy (ΔG°), standard enthalpy (ΔH°), and standard entropy (ΔS°), of the adsorption process were calculated. It was found that the adsorption of arsenic on chestnut shell was exothermic. The adsorbents were characterized by scanning electron microscopy. © 2014 Balaban Desalination Publications. All rights reserved.Item Removal of arsenic(III) ions from aqueous solutions by modified hazelnut shell(Desalination Publications, 2017) Sert S.; Çelik A.; Tirtom V.N.In this study, modified hazelnut shells (HS) were used to remove As(III) ions from aqueous solutions. For this purpose, FeCl3 and FeCl3 + NaOH were used as modifying agents. Several important parameters influencing the adsorption of As(III) ions such as contact time, pH, temperature and initial metal concentration were investigated following batch experiments. From the results, it is indicated that temperature 20°C and solution pH = 9.0 are the optimum conditions for adsorption. Maximum adsorption experimental capacities of HS that was treated with FeCl3 and FeCl3 + NaOH were 4.37 and 11.84 mg g-1 for arsenic, respectively. The adsorption data at optimum conditions were analyzed by Freundlich, Langmuir, Dubinin-Radushkevich and Temkin isotherm models, and it was found that Freundlich isotherm model gives better fit. Thermodynamic parameters such as enthalpy change (ΔH°), entropy change (ΔS°) and free energy change (ΔG°) were also calculated. These results were indicated that the adsorption of arsenic on HS is exothermic and proceeds spontaneously. Additionally, it can be said that these adsorptions are physical because the Gibbs free energy change (ΔG°) for both adsorbents were found lower than 20 kJ mol-1. © 2017 Desalination Publications. All rights reserved.Item Comparative adsorption of Pb(II) and Cd(II) ions on chestnut shell in aqueous system(Taylor and Francis Ltd., 2018) Çetinkaya S.; Targan Ş.; Tirtom V.N.In this study, high capacity Chestnut shell, a waste product from the chestnut sugar production industry, was successfully applied to remove Pb (II) and Cd (II) ions from aqueous solutions. Maximum adsorption capacities were found as 541.25 mg/g and 75.86 mg/g for Pb(II), and Cd(II) respectively. Several important parameters influencing the adsorption of Pb(II) and Cd(II) ions such as contact time, pH, temperature and effect of metal concentration were investigated systematically by batch experiments. Langmuir and Freundlich adsorption models were used to describe adsorption isotherms and constants. The thermodynamic parameters, such as standard free energy (ΔG°), standard enthalpy (ΔH°), and standard entropy (ΔS°), of the adsorption process were calculated. The adsorbents were characterised by scanning electron microscopy. It has been observed from the experimental results that in case of both Cd (II) and Pb (II), pseudo 2nd order kinetic model. From the results, Chestnut Shell are considered as an effective, low cost and environmental friendly adsorbent for the removal of Pb (II) and Cd (II) from wastewater. © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group.Item Comparative methods for online preconcentration of copper ions on epichlorohydrin cross linked silica gel-chitosan composite beads and epichlorohydrin crosslinked multi walled carbon nanotube-chitosan composite beads by flow injection system(Iranian Chemical Society, 2019) Çolak G.; Tirtom V.N.In this work, two different adsorbents were comparatively used and developed for preconcentration of ultra-trace levels of copper ions by flow injection analysis for atomic absorption spectrometry. Copper ions were preconcentrated on a mini-column packed with epichlorohydrin cross-linked silica gel-chitosan composite beads and epichlorohydrin cross linked multiwalled carbon nanotube-chitosan composite beads. 0.1 M ethylene diamine tetra acetic acid and 0.1 M nitric acid solutions were used in order to remove the copper ions from the adsorbents. The factors affecting preconcentration of copper(II) ions such as sample and eluent flow rate, loading time, pH, eluent concentration, and interfering ions were investigated. Under the optimized parameters, detection limits of the methods were obtained as 2 ng ml -1 for epichlorohydrin cross linked silica gel-chitosan composite beads and 1.3 ng ml -1 for epichlorohydrin cross linked multiwalled carbon nanotube-chitosan composite beads with enrichment factor of 23 and 19.2, respectively. The recoveries and intra-day and inter-day precisions for copper ions were >90.0% and >3%, respectively. In order to validate the developed methods, a certified reference material of drinking water was analyzed. The values determined were in good agreement with the certified values. The developed methods have also been applied for determination of copper(II) ions in Gediz River in Turkey with satisfactory results. © 2019, Iranian Chemical Society.Item Removal of lead from aqueous solutions by low cost and waste biosorbents (lemon, bean and artichoke shells)(IWA Publishing, 2020) Ergüvenerler F.; Targan Ş.; Tirtom V.N.Simple, fast, effective, low cost and waste biosorbents, lemon, bean and artichoke shells, were used to remove lead (II) ions from aqueous solution. The influence of pH, contact time, temperature and lead (II) concentration of the removal process was investigated. The sufficient contact time was deemed 10 minutes for bean and artichoke shells and 60 minutes for lemon shells for Pb(II) ions. The thermodynamic parameters, such as standard free energy (AG), standard enthalpy (AH), and standard entropy (AS) of the adsorption process were calculated as -5.6786, -5.5758, -3.1488 kJmol- 1 for AG, -7.2791, -20.285, -9.5561 kJ mol-1 for AH, -0.00545, -0.05017, -0.02185 kJ mol-1 K-1 for AS, respectively, for lemon, artichoke and bean shells. Maximum adsorption capacities of lead (II) were observed as 61.30 m g g - 1, 88.5 mgg- 1 and 62.81 m g g - 1, respectively, for lemon, bean and artichoke shells according to the Freundlich isotherm model at 20 °C. Scanning electron microscope (SEM) and energy-dispersive X-ray detector (EDX) were used to characterize the surface morphology of the adsorbents. Consequently, Pb(II) removal using lemon, bean and artichoke shells would be an effective method for the economic treatment of wastewater. © IWA Publishing 2020 Water Science & TechnologyItem Casein-copper hybrid nanoflowers: application in lead (II) and cadmium (II) ions removal from aqueous medium(Taylor and Francis Ltd., 2024) Tirtom V.N.; Akgöl C.; Dinçer A.In this study, eco-friendly casein-copper hybrid nanoflowers (CAS-Cu HNFs) were synthesised and their applicability for the removal of Pb(II) and Cd(II) ions was investigated. Hybrid nanoflowers were synthesised by adding CuSO4 solution on casein in PBS medium. According to the evaluation of SEM images, regular nanoflower structures were obtained after the addition of 40 µL of 100 mM CuSO4 and 12 h incubation. Characterisation studies were performed by XRD, SEM-EDX, FTIR and TGA. The effects of contact time, pH, temperature and heavy metal ion concentration on the adsorption performance were investigated. Optimum adsorption was achieved at 60 min contact time and 35 and 30 °C for Pb(II) and Cd(II) ions, respectively. The performance of CAS-Cu HNFs was evaluated by linear and non-linear forms of adsorption isotherms and adsorption kinetics, respectively. The linear Langmuir isotherm model showed compatibility and the maximum adsorption capacity was found to be 769.23 and 156.25 mg/g for Pb(II) and Cd(II) ions, respectively. CAS-Cu HNFs has great potential as an eco-friendly, nanoscale, flower-like, organic–inorganic hybrid nano-flower adsorbent for the effective removal of Pb(II) and Cd(II) ions from aqueous solutions. © 2024 Informa UK Limited, trading as Taylor & Francis Group.