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    Adsorptive performance of magnetic nano-biosorbent for binary dyes and investigation of comparative biosorption
    (Springer Nature, 2019) Tarhan, Tuba; Tural, Bilsen; Boğa, Kenan; Tural, Servet
    The individual and competitive biosorption capacities of Metanil Yellow (MY) and Reactive Black 5 (RB5) by glutaraldehyde cross-linked magnetic chitosan nanoparticles (GMCNs) were studied. Competitive biosorption of the MY and RB5 dyes by the GMCNs has never been reported previously. Fourier transform infrared technique has been used to show the biosorbed MY and RB5 dyes onto GMCNs. During the studies, various essential factors influencing the biosorption, like adsorbate concentration, pH of the solution and contact time have been monitored. The equilibrium was achieved within 17 h for single dyes and 3 h for binary mixture at pH 3. The biosorption capacities were 620 mg/g for dye MY and 2549 mg/g for dye RB5 at pH 3, 30 °C. The second-order kinetic model has good compatibility with the dynamical biosorption behavior of a single dye and binary mixture. In order to study the competition biosorption of the RB5 and MY dyes in mixture solutions, the intraparticle diffusion model was used. Competition biosorption through analysis of the intraparticle diffusion model apparently favored the RB5 dye more than the MY dye on the GMCNs in mixture solutions. The biosorbent was regenerated efficiently through the alkaline solution and was then reused ten times for biosorption–desorption cycles
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    Anot çamuru cürufundan altın ve gümüşün kazanılması
    (1994) Tural, Bilsen; Ziyadanoğulları, Recep
    Bu çalışmada kullanılan anot çamuru cürufu Kayseri yöremizde bulunan bir elektrolitik bakır fabrikasından temin edilmiştir. Altın ve gümüş kazanımı için tiyoüre yönteminden yararlanılmıştır. Bunun için örnek -90 meshe kadar öğütülüp homojen hale getirilerek analiz yapılmış ve örneğin tiyoüre özütlenmesi sonucu çözelti ortamına altının %6,23'ünün ve gümüşün %5,6'sınm alınabildiği saptanmıştır. Bundan sonra cüruf 0,1, 0,2, 0,3, 0,4, ve 0,5 M H2SO4 çözeltileri ile birer saat sürelerle karıştırılarak işleme konulmuş, çözelti katı kısımdan süzülerek ayrılmış ve deneylerin hiç birinde çözelti ortamına altın ve gümüşün geçmediği görülmüştür. Katı örnekler, aynı koşullar altında tiyoüre ekstrak- siyonuna tabi tutulmuş, maksimum reaksiyon veriminin altın için %16,2 ve gümüş için de %24,17 olduğu belirlenmiştir. Daha sonra orijinal cüruftan alman ellişer gramlık tanımlar %96'lık H2S04'in 4,6,8,10,12,15,18,21,24 ml'â ile ayrı ayrı iyice karıştırılarak 350°C'de gaz çıkışı tamamlanana kadar kavurma işlemine tabi tutulmuştur. Kavrulan örnekler su ile yıkanarak çözeltiye geçen altın ve gümüş değerleri saptanmış, deneylerin hiç birinde çözeltiye altının geçmediği, çözeltiye geçen gümüş miktarları, sülfürik asit miktarına paralel olarak arttığı ve en yüksek değerin 24 ml H2SO4 ile yapılan deney sonucu olup, bunun da %75,5 kadar olduğu görülmüştür. Bu çalışmalardan sonra 50 gram cürufun ıslanması için gerekli H2SO4 miktarı belirlenip, çeşitli sıcaklıklarda kavurma işlemleri yapılmıştır. Bunun içinde ellişer gramlık örnekler 10 mi %96'lık H2SO4 ile iyice karıştırılmış ve gaz çıkışı bitinceye kadar 450,500,550,600°C'de kavurma işlemine tabii tutulmuştur. Kavurma sonucu elde edilen örneklerin su ile yıkanmaları sonucu, çözeltiye gümüşün geçmediği deney koşulunun 600°C'de yapılan kavurma olduğu belirlenmiştir. Böylece 600°C'de yapılan kavurma sonucu elde edilen örneğin su ile yıkanarak süzülmesi ile ele geçen katı örneğin aynı koşullar alünda tiyoüre özütlenmesine tabi tutulması ile altının %72,2'sinin ve gümüşün de %73,4'ünün çözelti ortamına alınabildiği saptanmıştır. Bu elementlerin özütlenme verimlerim daha da yükseltmek için tanecik boyutu -130 ve - 160 meshe küçültülerek tiyoüre çözeltisi ile özütlenmeleri yapılmıştır. -130 ve -160 mesh deney sonuçlan karşılaştırıldığında -160 meshte gümüş veriminin biraz arttığı fakat altında bir değişme olmadığı görülmüştür. Bunun üzerine deneyler, altının %91,4 ve gümüşün %85,6 verimle özütlendiği -130 mesh ile sürdürülmüştür. Bundan son raki çalışmalarda 2, 3, 3,5 g/L Fe+3 çözeltileri kullanılarak ve diğer koşullar sabit tutularak, Fe+3 yükseltgeninin özütlenme verimi üzerine olan etkisi incelenmiştir. Katı/sıvı oram 35 g/200 ml'den 25 g/200 ml'ye düşürülmüş ve bunun da özütlenme verimim istenilen değere yükselttiğini göstermiştir. Altın %99,98 ve gümüş %96,39 verimle 2,5 saat özütlenmesi sonucu çözelti ortamına ahnmıştır.Bu deneydeki koşullar,
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    Anot çamurundan bakır, selenyum, tellür, kalay, altın, gümüş kazanılması ve kurşun uzaklaştırılması
    (Dicle Üniversitesi, Fen Bilimleri Enstitüsü, 1998) Tural, Bilsen; Ziyadanoğulları, Recep
    Bu çalışma, Kayseri' de üretim yapan özel bir Elektrolitik Bakır Fabrikasından temin edilen anot çamurundaki bakır, kurşun, selenyum, tellür, kalay, gümüş ve altın kazanılması amacıyla yapılmıştır. Araştırmanın birinci basamağında otoklav ortamında yapılan işlem sonucunda bakır çözeltiye alınmış selenyum ve tellür elementel hale dönüştürülmüştür. Kurşun, amonyumasetat çözeltisiyle özütlenerek %99.5'i çözelti ortamına alınmış ve selenyumun da tümü Na2S03 çözeltisiyle özütlenerek ayrılmıştır. Otoklav ortamında NaOH çözeltisiyle yapılan işlem sonucu kalayın %85'i, kurşun ve tellürün tümü çözelti ortamına alınmıştır. Atıkta kalan kalay NaOH kavurmasıyla kazanılmış ve kavurma çözeltisi kalay, tellür ve başlangıç kurşununun %0.5'ini içeren atığın otoklav ortamındaki ekstraksiyonunda kullanılmıştır. Bunun sonucunda da kalayın %92.6'sı, kurşun ve tellürün tümü çözelti ortamına alınmıştır. NaOH ekstraksiyonu sonucu çözelti ortamına alınan kalay, kurşun ve tellürün ayrılması için çalışmalar sürdürülmüştür. Çözelti pH'ı ayarlanarak SO2 gazı çözeltiden geçirilmiş, kurşun, PbS04 olarak, tellür elementel halde çöktürülmüş, kalay çözelti ortamında kalmıştır. Çöken kurşun ve tellür karışımı, amonyumasetat çözeltisiyle yıkanmış ve işlem sonucu kurşun çözelti ortamına alınarak geriye saf halde elementel tellür kalmıştır. Çözeltide kalan kalay, elektroliz ile kazanılmıştır. Altın ve gümüş kazanılması için farklı işlemler yapılmıştır. İşlem görmüş anot çamuru tiyoüre ile özütlenmiş, fakat istenilen verimler elde edilememiştir. Bunun üzerine gümüş, HNO3 ve altın da kral suyu ile özütlenerek, gümüş ve altının tümü çözelti ortamına alınmıştır. Tiyoüre yönteminin uygulanması halinde önceden gümüşün altından ayrılması için HNO3 özütlenmesi yapılmıştır. Daha sonra altın tiyoüre özütlenmesine tabi tutularak %99.7'si çözelti ortamına alınmıştır.
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    Biosorption of Diclofenac by Magnetic Biosorbent (M-EColi)
    (Jihad Daneshgahi, 2024) Ertas, Erdal; Tural, Bilsen; Tural, Servet
    Diclofenac sodium (DCF), 2-[(2,6-dichlorophenyl)amino] benzene acetic acid, monosodium salt is widely used as a non-steroidal anti-inflammatory drug with high consumption. It therefore presents a serious risk to both human health and the environment and is among the pharmaceuticals that are most commonly found in aqueous effluents. In this study, a novel magnetic biosorbent (M-EColi) was successfully prepared by immobilizing Escherichia coli (E.coli) on nano- sized magnetic iron oxides, and its efficacy in DCF biosorption was investigated. To determine the characterization of the synthesized M-EColi biosorbents, Vibrational Sample Magnetometry (VSM), Scanning Electron Microscope (SEM), Energy Dispersive X-ray (EDX) spectroscopy Fourier Transform & Idot;nfraRed Red (FT-IR) spectroscopy analyses were performed and the effects of contact time, temperature, biosorbent dose and initial DCF concentration on the biosorption process were investigated. Isothermal, kinetic, and thermodynamic calculations were performed to determine which mechanism is consistent with biosorption. It was found that the DCF biosorption on M-EColi corresponded to the Langmuir isotherm and the biosorption kinetics corresponded to the pseudo-second-order kinetic model. The thermodynamic analyses indicate that the biosorption of DCF on the M-EColi nano-sorbent is physical. The maximum biosorption capacity was found to be 46.01 +/- 0.12 mg/g.
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    Biosorption of phenolic compounds from aqueous solutions onto magnetic chitosan nanoparticles
    (Amer Chemical Soc, 2014) Tural, Bilsen; Ertas, Erdal; Tural, Servet
    [Abstract Not Available]
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    Carboligation reactions catalyzed by benzaldehyde lyase (BAL, EC 4.1.2.38) covalently attached to epoxysilane modified Fe3O4@SiO2 nanoparticles
    (Amer Chemical Soc, 2011) Tural, Bilsen; Turan, Ilke Simsek; Celebi, Bulent; Yalinkilic, Ibrahim; Demir, Ayhan S.
    [Abstract Not Available]
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    Carboligation reactions mediated by benzoylformate decarboxylase immobilized on a magnetic solid support
    (Wiley, 2013) Tural, Bilsen; Tural, Servet; Demir, Ayhan S.; 0000-0001-7555-2481; 0000-0003-2479-9438
    In this study, magnetic nanoparticles (Fe3O4, magnetite) with immobilized metal affinity ligands (MSS) were prepared and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), fourier transform infrared spectroscopy (FTIR), and vibrating-sample magnetometer (VSM) methods for purification and immobilization of the histidine-tagged recombinant benzoylformate decarboxylase (BFD). The MSS support was shown to be eligible for selective binding of HIS-tagged BFD by SDS-page analysis. Loading capacity of the MSS support was determined as 43.6 +/- 1.1mg/g. The regeneration ability for protein binding was also studied. An immobilized BFD was tested to catalyze benzoin condensation and representative cross acyloin reaction. Conversion and enantiomeric excess values were comparable with that of free enzyme catalyzed reactions. (C) 2013 Wiley Periodicals, Inc.
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    Carboligation reactions with benzaldehyde lyase immobilized on superparamagnetic solid support
    (Royal Soc Chemistry, 2009) Sopaci, S. Betuel; Turan, Ilke Simsek; Tural, Bilsen; Volkan, Muervet; Demir, Ayhan S.
    Histidine-tagged recombinant benzaldehyde lyase (BAL, EC 4.1.2.38) was efficiently immobilized to surface-modified magnetic particles with affinity ligand binding. In addition to conventional benzoin condensation reactions, two important representative BAL-catalyzed carboligation reactions, were also performed with this magnetically responsive biocatalyst. The results obtained from the carboligation reactions that were performed with this simple and convenient heterogenous biocatalyst were comparable to that of free-enzyme-catalyzed reactions.
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    Carboligation reactivity of benzaldehyde lyase (BAL, EC 4.1.2.38) covalently attached to magnetic nanoparticles
    (Pergamon-Elsevier Science Ltd, 2013) Tural, Bilsen; Turan, Ilke Simsek; Tural, Servet; Celebi, Bulent; Demir, Ayhan S.
    Epoxy-functionalized Fe3O4-SiO2 core-shell magnetic nanoparticles (epoxy-M-support) were prepared by modification with glycidyloxypropyltrimethoxysilane (GPTMS) and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and fourier transform infrared spectroscopy (FTIR) methods. Pure histidine-tagged recombinant benzaldehydelyase (BAL, EC 4.1.238) was efficiently immobilized onto the epoxy-M-support with covalent binding. An immobilized BAL epoxy-M-support system was tested to catalyze the self and cross condensation reactions of aldehydes, and the kinetic resolution of racemic acyloins. The acyloin products were obtained in high yield and with high enantiomeric excesses (>= 98% ee). The carboligation reactivity of the immobilized enzyme was comparable to that of free enzyme-catalyzed reactions. The covalent immobilization offers high enzyme activity and stability (at least 5 repeats without losing its activity). (C) 2013 Elsevier Ltd. All rights reserved.
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    Comparative study on silver nanoparticle synthesis using male and female pistacia khinjuk leaf extracts: Enhanced efficacy of female leaf extracts
    (John Wiley and Sons Inc, 2024) Tural, Bilsen; Ertaş, Erdal; Batıbay, Hayri; Tural, Servet
    This study aims to uncover the potential differences in bioactive compounds present in leaf extracts obtained from female and male individuals of Pistacia khinjuk, abundantly found in the Southeast Anatolia region of Turkey, and their roles in influencing the properties of synthesized silver nanoparticles (AgNPs). Results obtained through TEM and SEM imaging techniques determined the morphology and size of AgNPs synthesized from female (FL-AgNPs) and male (ML-AgNPs) leaf extracts. Additionally, FTIR spectrum analysis demonstrated the chemical composition of the FL-AgNPs, ML-AgNPs, and the extracts. Zeta potential and zeta sizer analyses revealed differences between nanoparticles obtained from female and male plants. The total phenolic content of leaf extracts from female plants is significantly higher than that obtained from male plants (female plants: 30.68±0.26 mg GAE/g, male plants: 24.22±0.37 mg GAE/g). Furthermore, FL-AgNPs (43.2±2.64 mg GAE/g) exhibit higher antioxidant activity compared to ML-AgNPs (31.7±1.16 mg GAE/g). ICP-MS analyses indicate that FL-AgNPs are synthesized with higher efficiency compared to ML-AgNPs (FL-AgNPs: 99.90±0.106 %, ML-AgNPs: 94.99±0.079 %). Finally, the antibacterial efficacy of FL-AgNPs and ML-AgNPs nanoparticles was evaluated agar well diffusion method against the pathogen Escherichia coli (E.Coli) and Staphylococcus aureus (S. Aureus].
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    Covalent immobilization of benzoylformate decarboxylase from Pseudomonas putida on magnetic epoxy support and its carboligation reactivity
    (Elsevier Science Bv, 2014) Tural, Bilsen; Tarhan, Tuba; Tural, Servet
    Epoxy attached magnetic nanoparticles were prepared and used as solid support for covalent immobilization and stabilization of benzoylformate decarboxylase (BFD, E.C. 4.1.1.7) from Pseudomonas putida. A three-step immobilization/stabilization procedure is applied. The enzyme is firstly covalently immobilized under mild experimental conditions (e.g. pH 7.0, no added MgSO4 and 20 degrees C). Secondly, the enzyme is immobilized under more drastic conditions (higher pH values, higher ionic strengths, etc.) to facilitate an increase in effective concentration of the enzyme on the support near the epoxide reactive sites. Thirdly, the remaining epoxy groups are blocked to stop any additional interaction between the enzyme and the support. With more drastic conditions, the loading of enzyme can be increased from 1.25 to 6.70 mg enzyme per gram of support. The covalently bounded enzyme was characterized in terms of its activity and stability for the formation of (S)-2-hydroxypropiophenone (2-HPP). The activity of the immobilized BED was determined to be 53.0% related to the activity of the free enzyme. The immobilized biocatalyst retained 95% of its original activity after five reaction cycles. (C) 2014 Elsevier B.V. All rights reserved.
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    Effect of structural differences of pumice on synthesis of pumice-supported nFe(0): removal of Cr (VI) from water
    (Springer Heidelberg, 2021) Tural, Bilsen; Ertaş, Erdal; Güzel, Mehmet; Tural, Servet
    In this study, pumice from diferent regions of Turkey (Diyarbakir, Southeast Turkey and Bitlis, East Turkey) has been supplied and used as supporting material for nanoscale zero-valent iron (nFe0 ). Native Bitlis pumice (NBP)-supported nanoscale zero-valent iron (BP-nFe0 ) and native Diyarbakir pumice (NDP)-supported nanoscale zero-value iron (DP-nFe0 ) were synthesized under the same conditions. Native pumice (NDP, NBP) and pumice-supported nFe0 (DP-nFe0 and BP-nFe0 ) adsorbents were morphologically and structurally characterized by SEM, EDX, XRF and BET. When using NBP as support material, the iron content of the BP-nFe0 increased 1.9-fold from 1.99 to 3.83%. However, iron content of NDP (2.08%) increased approximately 29 times after it is used as a support material in synthesis of DP-nFe0 (60%). The removal potential of native pumice (NBP and NDP) and iron-modifed pumice (BP-nFe0 and DP-nFe0 ) samples was investigated to remove Cr(VI) ions. The parameters of solution pH, initial metal concentration, contact time and the amount of adsorbent in the removal of chromium (VI) ions were investigated. Langmuir, Freundlich, Temkin, Dubinin–Radushkevich and Jovanovic isotherm models were used to evaluate the adsorption equilibrium data. The equilibrium adsorption was found so as to be well described by the Langmuir isotherm model for all the adsorbents studied. The maximum adsorption capacity of Cr(VI) ions for NDP, NBP, DP-nFe0 and BP-nFe0 was 10.82, 14.30, 161.29 and 17.39 mg/g, respectively. The rate of Cr(VI) removal was subjected to kinetic analysis using pseudo-frst-order, pseudo-second-order, intraparticle difusion and Elovich models. Kinetic studies suggest that adsorption of NDP, NBP, DP-nFe0 and BP-nFe0 described more favorably by the pseudo-second-order kinetic model. The results showed that NDP is a much better support material for nFe0 when compared to NBP
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    Enantioseparation of mandelic acid enantiomers with magnetic nano-sorbent modified by a chiral selector
    (Wiley, 2015) Tarhan, Tuba; Tural, Bilsen; Tural, Servet; Topal, Giray; 0000-0001-7555-2481; 0000-0003-2479-9438; 0000-0002-7056-3912; 0000-0003-2656-4464
    In this study, R(+)--methylbenzylamine-modified magnetic chiral sorbent was synthesized and assessed as a new enantioselective solid phase sorbent for separation of mandelic acid enantiomers from aqueous solutions. The chemical structures and magnetic properties of the new sorbent were characterized by vibrating sample magnetometry, transmission electron microscopy, Fourier transform infrared spectroscopy, and dynamic light scattering. The effects of different variables such as the initial concentration of racemic mandelic acid, dosage of sorbent, and contact time upon sorption characteristics of mandelic acid enantiomers on magnetic chiral sorbent were investigated. The sorption of mandelic acid enantiomers followed a pseudo-second-order reaction and equilibrium experiments were well fitted to a Langmuir isotherm model. The maximum adsorption capacity of racemic mandelic acid on to the magnetic chiral sorbent was found to be 405 mg g(-1). The magnetic chiral sorbent has a greater affinity for (S)-(+)-mandelic acid compared to (R)-(-)-mandelic acid. The optimum resolution was achieved with 10 mL 30 mM of racemic mandelic acid and 110 mg of magnetic chiral sorbent. The best percent enantiomeric excess values (up to 64%) were obtained by use of a chiralpak AD-H column. Chirality 27:835-842, 2015. (c) 2015 Wiley Periodicals, Inc.
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    Heterofunctional magnetic metal-chelate-epoxy supports for the purification and covalent immobilization of benzoylformate decarboxylase from pseudomonas putida and its carboligation reactivit
    (Wiley, 2015) Tural, Servet; Tural, Bilsen; Demir, Ayhan Sıtkı; 0000-0003-2479-9438; 0000-0001-7555-2481; Tural, S., Tural, B. ve Demir, A. S. (2015). Heterofunctional magnetic metal-chelate-epoxy supports for the purification and covalent immobilization of benzoylformate decarboxylase from pseudomonas putida and its carboligation reactivit. Chirality, 27(9), 635-642.
    In this study, the combined use of the selectivity of metal chelate affinity chromatography with the capacity of epoxy supports to immobilize poly-His-tagged recombinant benzoylformate decarboxylase from Pseudomonas putida (BFD, E.C. 4.1.1.7) via covalent attachment is shown. This was achieved by designing tailor-made magnetic chelate-epoxy supports. In order to selectively adsorb and then covalently immobilize the poly-His-tagged BFD, the epoxy groups (300 mu mol epoxy groups/g support) and a very small density of Co2+-chelate groups (38 mu mol Co2+/g support) was introduced onto magnetic supports. That is, it was possible to accomplish, in a simple manner, the purification and covalent immobilization of a histidine-tagged recombinant BFD. The magnetically responsive biocatalyst was tested to catalyze the carboligation reactions. The benzoin condensation reactions were performed with this simple and convenient heterogeneous biocatalyst and were comparable to that of a free-enzyme-catalyzed reaction. The enantiomeric excess (ee) of (R)-benzoin was obtained at 99 +/- 2% for the free enzyme and 96 +/- 3% for the immobilized enzyme. To test the stability of the covalently immobilized enzyme, the immobilized enzyme was reused in five reaction cycles for the formation of chiral 2-hydroxypropiophenone (2-HPP) from benzaldehyde and acetaldehyde, and it retained 96% of its original activity after five reaction cycles. Chirality 27:635-642, 2015. (c) 2015 Wiley Periodicals, Inc.
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    The Impact of Pistacia khinjuk plant gender on silver nanoparticle synthesis: Are extracts of root obtained from female plants preferentially used?
    (Academic Press Inc Elsevier Science, 2025) Tural, Bilsen; Ertas, Erdal; Batibay, Hayri; Tural, Servet
    Pistacia khinjuk, a dioecious plant native to Southeast Anatolia, Turkey, features distinct male and female individuals with varying bioactive compound profiles. This study investigates the gender-specific phytochemical composition of root extracts from male and female Pistacia khinjuk plants and their influence on the green synthesis of silver nanoparticles. Using natural bioactive compounds such as polyphenols, flavonoids, alkaloids, and terpenoids as reducing and stabilizing agents, the study demonstrates significant differences between the nanoparticles synthesized from male and female root extracts. Female root extracts, with their higher poly- phenolic content, produced silver nanoparticles that were smaller in size (150.1 nm) and more stable, as indicated by a zeta potential of-32.5 mV. In comparison, the silver nanoparticles synthesized from male root extracts were larger in size (213.8 nm) and exhibited a less negative zeta potential of-21.36 mV. Additionally, silver nanoparticles derived from female root extracts showed superior antioxidant activity and greater antibacterial efficacy against Staphylococcus aureus and Escherichia coli, as reflected in larger inhibition zones. These findings highlight the potential of Pistacia khinjuk root extracts for sustainable nanoparticle synthesis and underscore the value of gender-specific bioactive compounds in advancing green technologies and biomedical applications.
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    Investigation of Cr(VI) sorption from aqueous solution on M-TACA magnetic nano-sorbent
    (Springer Science and Business Media, 2023) Ertaş, Erdal; Tural, Bilsen; Tural, Servet
    In this study, a magnetic nano-sorbent (M-TACA) was linked with an N-methyl-d-glucamine (NMDG) picky functional group using click chemistry, which is rapid, multifunctional, easy to use, and produces a large amount of product that is selective to the target site. M-TACA were detected using scanning electron microscopy (SEM) and vibrating-sample magnetometry (VSM) techniques. The efects of pH, contact time, initial Cr(VI) ion concentration, and M-TACA dosage on the sorption process were examined. The sorption capacity of Cr(VI) ions to M-TACA nanoparticles difers depending on pH. The maximum sorption capacity of Cr(VI) ions to M-TACA nanoparticles was determined to be 117.65 mg/g at pH 3. The efects of cationic ions Cu2+, Zn2+, and Ni2+ and anionic ions Cl−, PO4 3−, and SO4 2− on the removal of Cr(VI) were also investigated. Sorption is more compatible with the Langmuir isotherm model than any other applied isotherm model. The Langmuir isotherm model for sorption was shown to be more compatible than the other models among the isotherm model research. Intra-particle difusion model was applied for the Cr(VI) ions sorption mechanism. Both surface and intra-particle sorption are clearly diferent from one another in the two sorption stages. According to the M-TACA-Cr(VI) sorption systems computed thermodynamic characteristics, the process was exothermic, spontaneous, and mixed physicochemical in nature. Moreover, in reusability studies, M-TACA nano-sorbent was found to retain 96.8% sorption capacity after fve consecutive repetitions.
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    Investigation of some 1,3-diols for the requirements of solvent extraction of boron: 2,2,6-trimethyl-1,3 heptanediol as a potential boron extractant
    (Tubitak Scientific & Technological Research Council Turkey, 2007) Tural, Bilsen; Tural, Servet; Hosgoren, Halil
    Eighteen 1,3-diols were syntesized and their structure and distribution ratio for the solvent extraction of boron were studied. Diols with a high distribution ration (DB(OH)3 > 10) were investigated for the requirements of solvent extraction of boron. Their extraction capacity, and solubility in aqueous phase and in organic diluents were investigated by comparison to 2-ethyl-1,3-hexanediol (EHD), which is widely used as a boron extractant. Among a series of 1,3 diols, 1-benzyl-2,2-dimethyl-1,3-propanediol (4a) and 2,2,6-trimethyl-1,3-heptanediol (3a) were found to have very low solubility in the aqueous phase compared to the others. IPD (3a) was found to have a high solubility in aliphatic diluents such as kerosene. IPD, which has good solubility properties for the solvent extraction of boron, was studied in detail, including dependence of pH, diol concentration, and stripping facility, and in various organic diluents.
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    Investigation of some 1-3-diols for the requirements of solvent extraction of boron: 2,2,6-trimethyl-1,3 heptanediol as a potential boron extractant
    (2007) Hoşgören, Halil; Tural, Servet; Tural, Bilsen
    Eighteen 1,3-diols were synthesized and their structure and distribution ratio for the solvent extraction of boron were studied. Diols with a high distribution ratio $(D_{B(OH)_3} > 10)$ were investigated for the requirements of solvent extraction of boron. Their extraction capacity, and solubility in aqueous phase and in organic diluents were investigated by comparison to -ethyl-1,3-hexanediol (EHD), which is widely used as a boron extractant. Among a series of 1,3 diols, 1-benzyl-2,2-dimethyl-1,3-propanediol (4a) and 2,2,6-trimethyl-1,3-heptanediol (3a) were found to have very low solubility in the aqueous phase compared to the others. IPD (3a) was found to have a high solubility in aliphatic diluents such as kerosene. IPD,which has good solubility properties for the solvent extraction of boron, was studied in detail, including dependence of pH, diol concentration, and stripping facility, and in various organic diluents.
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    Investigation of the arsenic(V) retention performance of the nano-sorbent (M-TACA) synthesized by click chemistry
    (Taylor & Francis, 2022) Tural, Bilsen; Ertaş, Erdal; Tural, Servet
    In this study N-methyl-D-glucamine selective functional group is bound to magnetic nanoparticles (M-TACA) with click chemistry, which is fast, simple to use, easy to purify, versatile, region-specific and gives high product yield. The synthesized M-TACA nano-sorbent was characterized by SEM and VSM techniques. The parameters effecting sorption of As(V) onto M-TACA such as dosage, initial concentration of As(V), contact time and pH were studied. Sorption of As(V) onto M-TACA nano-sorbent is pH dependent and the maximum sorption capacity was obtained at pH 6 as 76.54 +/- 1.21 mg/g. The effects of fluoride, sulfate and phosphate ions, which compete with As(V) to hold active groups, on the sorption of As(V) were investigated. Fluoride has minimal effect on arsenic uptake. It is sulfate that has the most negative effect on intake and phosphorus has had a less negative effect. Sorption is more compatible with the Langmuir isotherm model than any other applied isotherm model. Results obtained from intra particle diffusion model shown the two sorption stages indicating that both surface and intra-particle sorption occurs. At the same time, sorption percentages for five times reusability were determined as 99.6 +/- 2.5%, 99.0 +/- 3.0%, 98.6 +/- 3.1%, 97.0 +/- 3.5% and 96.6 +/- 3.8%, respectively. The reusability results showed that the M-TACA nano-sorbent can be reused at least 5 times in removal of As(V).
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    Kimya lisans öğrencilerinin öğretmenlik mesleğine yönelik tutumları ile kimya öğrenmeye ilişkin görüşlerin saptanması
    (Cahit Aydemir, 2004) Tümerdem, Recep; Tural, Servet; Tural, Bilsen
    Öz:Bugün bir insanın belirli bir konuyla ilgili tutumu özel hazırlanıp, denenmiş tutum soruları ile sayısal olarak belirlenebiliyor. Öğrenme; eğitim, öğretim aktivitesi içinde yer alan bir proses olup, kişinin çevresiyle etkileşimi ve yaşantısı sonucu davranış kazanması ya da davranışlarını değiştirmesi süreci olarak tanımlanabilmektedir. Bu yön eylem çalışmasında, D.Ü. Eğitim fakültesi Kimya Anabilim Dalı III. ve IV. Sınıf öğrencileri ile Fen-Edebiyat Fakültesi Kimya Bölümü III. ve IV. Sınıf öğrencilerine % 94 güvenilirlikte bir tutum testi uygulanarak, onların öğretmenlik mesleğine yönelik tutumlarının ölçülmesi ve her biri beş şıklı, on soruluk, “kimya öğrenme ile ilgili görüşlerin saptanması”na yönelik anket uygulanarak ta, öğrenci açısından kimya öğrenme ile ilgili bir profil çizilmesi amaçlanmıştır. III. ve IV. Sınıf öğrencilerinin konulara bakış açıları arasında bir fark olup, olmadığının tespiti kadar, iki fakülte öğrencilerinin yaklaşımlarında da bir fark olup olmadığının belirlenmesi ilgi çekici olarak değerlendirildi. Yorumlar, aritmetik ortalamalara göre yapıldı.