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    Adsorption kinetics of Cu(II) and Ni(II) ions using clay in Kulp district of Diyarbakır province
    (Gazi Üniversitesi Fen Bilimleri Enstitüsü, 2023) Buldağ, Emine; Yavuz, Ömer
    In this study, the adsorption kinetics of Cu (II) and Ni (II) ions in the aqueous medium of the natural clay sample found in Kulp district of Diyarbakır province were investigated. For this purpose, the characterization of the natural clay mineral found in Kulp district of Diyarbakır province was carried out using X-Ray (XRD and XRF) and BET methods. The copper and nickel from the aqueous medium was measurmented at 25, 35 and 45 degrees. When the obtained data were applied to other models, it was found that it followed the Ho McKay equation for both ions. The qmax values here were measured as 1.51, 2.05, 2.30 for Cu (II) and 1.044, 1.086 and 1.741 for Ni (II) at the working temperatures, respectively. The increase in qmax values shows the accuracy of our study.
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    Adsorption of cobalt (II) ions from aqueous solution using orange peel waste: equilibrium, kinetic and thermodynamic studies
    (Springer, 2022) Altunkaynak, Yalçın; Canpolat, Mutlu; Yavuz, Ömer
    This study describes the evaluation of orange peel waste (OPW) to remove Co(II) ions from aqueous solutions. First, parameters such as pH, initial metal ion concentration, and contact time, which affect the adsorption efficiency, were studied. It was determined that the best initial Co(II) ion concentration, the adsorption contact and the solution pH were 125 mg/L, 100 min and 5.47, respectively. The surface properties of the orange peel were investigated using SEM, energy-dispersive spectroscopy, scanning and FTIR. The results showed that the isotherm data fit the Langmuir isotherm model, which corresponds to chemisorption and possible irreversibility of the process. The adsorption capacity for Co(II) was calculated to be 4.257, 4.491 and 5.128 mg/g at 298, 308 and 318 K, respectively. As a result of the adsorption kinetic data, it was determined that the adsorption of Co(II) metal ion conformed with the second-order kinetic model. Thermodynamic studies showed that the adsorption of Co(II) ion on orange peel is spontaneous and exothermic. It was shown that OPW can be used as an effective and alternative material in the removal of Co(II) ions from aqueous media due to its high capacity, easy availability and low cost.
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    Adsorption of mercury (II) ions on kaolinite from aqueous solutions: Isothermal, kinetic, and thermodynamic studies
    (John Wiley and Sons Inc., 2023) Altunkaynak, Yalçın; Canpolat, Mutlu; Yavuz, Ömer
    Indexed keywords SciVal Topics Abstract Due to industrial activity, heavy metal contamination is present in water, air, and soil around the world. Due to this circumstance, serious environmental issues arise. Natural kaolin (NK) clay underwent batch processing to remove Hg2+. Scanner electron microscopy (SEM), energy dispersion spectroscopy (EDS), x-ray diffraction (XRD), and Brunauer–Emmett–Teller (BET) were used to analyze the morphological and chemical characteristics of kaolin. Investigations were done into how adsorption is impacted by contact duration, adsorbent dosage, temperature, and solution pH. Kaolin's BET surface area was found to be 8.085 m2/g, while its pore volume was found to be 0.0537 cm3/g. The best working conditions were found to be pH 6.81 and an equilibrium period of 90 min. It was discovered that the Langmuir isotherm model was the most suitable one. At 298, 308, and 318 K, respectively, the adsorption capacities of NK were calculated to be 10.964, 10.515, and 10.101 mg/g. The pseudo-second-order kinetic model agreed with this. It was revealed that NK had a maximum desorption efficiency of 91.36%. Through this process, the potential of NK as an eco-friendly adsorbent for heavy metal removal was shown.
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    Diyarbakır-Batman çevresinde yetişen bazı şapkalı mantarların kimyasal element tayini
    (2003) Yıldız, Abdunnasır; Yeşil, Ömer Faruk; Yavuz, Ömer; Karakaplan, Mehmet
    Makrofunguslar, Türkiye'nin Diyarbakır, Batman ili ve çevresinde toplanmıştır. Diyarbakır' da, 18 familyaya ait 30 tür teşhis edilmiştir. Farklı yerlerden toplanan 49 makrofungus örneğinin analizi yapılmıştır. En yüksek Pb miktarı, 5.16 ppm olarak Hevsel Bahçeleri' nden toplanan Naematoloma fasciculare" de; en yüksek Cd miktarı 9.48 ppm olarak Amanita vaginata' da; Fe miktarı 251.62 olarak Agaricus bisporus' da; Mn miktarı 146.89 olarak Amanita vaginata' da; Zn miktarı 154.28 olarak Flammulina velutipes' de; Co miktarı 36.27 olarak Coprinus micaceus' da; en yüksek Cu miktarı Dicle Üniversitesi Kampus' ünden toplanan Flammulina velutipes' de 92.49 olarak belirlenmiştir. Batman ilinde 12" familya da 21 tür teşhis edilmiştir. Farklı alanlardan toplanan 29 makrofungus örneğinin analizi yapılmıştır. En yüksek Pb ve Cu miktarı; sırasıyla 2.14 ve 87.56 ppm olarak Russula rubroalbd' da; Cd miktarı Batman' in Hilal Mahallesi' nden toplanan Agaricus xanthodermus' da 19.72 ppm; Fe miktarı 464.95 olarak Funalia trogif de; Mn miktarı 415.3 ppm olarak Mycena personsii' de; Zn miktarı 277.56 ppm olarak Morchella esculenta' da; Co miktarı 16.79 ppm olarak Agaricus xanthodermus' da bulunmuştur. En düşük Cd, Cu ve Mn miktarı Inonotus hispidus' da tespit edilmiştir. Diyarbakır, Batman İli ve çevresinde toplanan örneklerde, en yüksek protein oranı (100 g. kuru ağırlıkta) sırasıyla; Dicle Üniversitesi Kampusu' nden toplanan Agaricus bisporus' da 51.244, Gercüş İlçesi' nin Yolağzı Köyü' nden toplanan Tricholoma ustale' de 50.519 olarak tespit edilmiştir. Sonuç olarak; protein ile organik ve inorganik element oramnın yetişme yerine ve türe göre değiştiği belirlenmiştir.
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    Firstly electrochemical examination of vildagliptin at disposable graphite sensor: Sensitive determination in drugs and human urine by square-wave voltammetry
    (Elsevier, 2021) Altunkaynak, Yalçın; Yavuz, Ömer; Levent, Abdulkadir
    The work describes the determination of vildagliptin at the pencil graphite electrode using cyclic voltammetry and square-wave voltammetry. Vildagliptin yielded a well-defined irreversible peak response in phosphate buffer (PBS 9.0) medium, at about +1.13 V by cyclic voltammetry. Using optimum square-wave voltammetry condi-tions, a good linear correlation was obtained between the anodic current signal and concentration, in the range of 2.94-49.98 mu M in PBS (pH 9.0) medium, the limit of detection and relative standard deviation were calculated as 82 nM (24.88 ng L-1) and 2.95%, respectively. The developed voltammetric method was successfully applied for vildagliptin determination without any separation in pharmaceutical preparations and urine samples.
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    Green synthesis, characterization of gold nanomaterials using gundelia tournefortii leaf extract, and determination of their nanomedicinal (Antibacterial, antifungal, and cytotoxic) potential
    (Hindawi LTD, 2022) Keskin, Cumali; Baran, Ayşe; Baran, Mehmet Fırat; Hatipoğlu, Abdulkerim; Adican, Mehmet Tevfik; Atalar, Mehmet Nuri; Yavuz, Ömer; Kandemir, Sevgi İrtegün
    Introduction. Fighting against cancer and antibiotic resistance are important challenges of healthcare systems, and developing new treatment methods has become the most concentrated area of researchers. Method and Materials. Green synthesis, characterization, and some biological activities of gold nanomaterials (AuNPs) obtained with Gundelia tournefortii (kenger) leaf extract were investigated in this study. Fourier scanning electron microscope, UV-visible spectrophotometer, Fourier transform infrared spectroscopy, energy-dispersive X-ray spectrophotometer, X-ray diffraction diffractometer, transmission electron microscope, and Zetasizer instrument data were used to elucidate the structures of nanoparticles. Results. The maximum surface plasmon resonance was observed at 532.15 nm after 1 hour. With the powder XRD model, the mean cubic crystallite size was determined as 23.53 nm. It was observed that the shapes of the obtained AuNPs were spherical, and the dimensions were 5-40 nm and hexagonal. Surface charges (-27 mV) and average size (365.3 nm) of gold nanoparticles were measured with a zeta analyzer. Conclusion. The suppressive effects of AuNPs on the growth of pathogenic microorganisms and healthy and cancer cell lines were determined using the MIC and MTT methods, respectively.
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    Investigation of antimicrobial and cytotoxic properties and specification of silver nanoparticles (AgNPs) derived from cicer arietinum L. green leaf extract
    (Frontiers Media SA, 2022) Baran, Ayşe; Baran, Mehmet Fırat; Keskin, Cumali; Hatipoğlu, Abdulkerim; Yavuz, Ömer; Kandemir, Sevgi İrtegün
    Using biological materials to synthesize metallic nanoparticles has become a frequently preferred method by researchers. This synthesis method is both fast and inexpensive. In this study, an aqueous extract obtained from chickpea (Cicer arietinum L.) (CA) leaves was used in order to synthesize silver nanoparticles (AgNPs). For specification of the synthesized AgNPs, UV-vis spectrophotometer, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction analysis (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), electron dispersive X-ray (EDX), and zeta potential (ZP) analyses data were used. Biologically synthesized AgNPs demonstrated a maximum surface plasmon resonance of 417.47 nm after 3 h. With the powder XRD model, the mean crystallite dimension of nanoparticles was determined as 12.17 mm with a cubic structure. According to the TEM results, the dimensions of the obtained silver nanoparticles were found to be 6.11-9.66 nm. The ZP of the electric charge on the surface of AgNPs was measured as -19.6 mV. The inhibition effect of AgNPs on food pathogen strains and yeast was determined with the minimum inhibition concentration (MIC) method. AgNPs demonstrated highly effective inhibition at low concentrations especially against the growth of B. subtilis (0.0625) and S. aureus (0.125) strains. The cytotoxic effects of silver nanoparticles on cancerous cell lines (CaCo-2, U118, Sk-ov-3) and healthy cell lines (HDF) were revealed. Despite the increase of AgNPs used against cancerous and healthy cell lines, no significant decrease in the percentage of viability was detected.
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    Kimyasal olarak işlenmemiş Midyat taşı kullanılarak sulu çözeltilerden Pb(II) iyonlarının etkin bir şekilde uzaklaştırılması: İzoterm, kinetik ve termodinamik çalışmalar
    (Niğde Ömer Halisdemir Üniversitesi, 2022) Canpolat, Mutlu; Altunkaynak, Yalçın; Yavuz, Ömer
    Endüstriyel atıklardan ağır metallerin uzaklaştırılması bilim insanlarının çözüm aradığı en önemli konulardan biridir. Bu araştırma, sulu çözeltilerden Pb2+ iyonlarının adsorpsiyonu için Midyat taşının (MT) değerlendirilmesini inceliyor. Çalışmada, temas süresi, başlangıç metal iyon konsantrasyonu, pH gibi çeşitli değişkenlerin adsorpsiyon verimliliği üzerindeki sonuçları araştırıldı. MT'nin yüzey özellikleri taramalı elektron mikroskobu, enerji dağılım spektroskopisi ve Fourier dönüşümlü kızılötesi spektroskopisi ile araştırıldı. Pb2+ iyonunun uzaklaştırılması için en uygun çalışma koşullarında başlangıç konsantrasyonu, temas süresi ve çözelti pH'ı sırasıyla 800 mg/L, 90 dakika ve 4,23 olarak belirlendi. Sonuçlar, izoterm verilerinin Langmuir izoterm modeli için, kinetik verileri için de Yalancı birinci dereceden kinetik modeline (PSO) uygun olduğunu göstermiştir. Pb2+ iyonu için adsorpsiyon kapasitesi 298, 308 ve 318 K'da sırasıyla 129.87 mg/g, 178.57 mg/g ve 188.68 mg/g olarak hesaplandı. Termodinamik çalışmalar, MT yoluyla Pb2+ iyonunun uzaklaştırılmasının doğal ve endotermik olduğunu göstermiştir. MT'nin sahip olduğu yüksek adsorpsiyon kapasitesi, ucuz ve kolay bulunabilmesi gibi özelliklerinden dolayı Pb2+ iyonlarının sulu ortamdan uzaklaştırılmasında etkili ve gelecek vaat eden bir malzeme olduğu tespit edilmiştir.
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    Kinetic and Thermodynamic Studies on the Use of Waste Orange Peel in the Removal of Pb2+ Ions from Aqueous Solutions
    (Düzce Üniversitesi, 2023) Altunkaynak, Yalçın; Canpolat, Mutlu; Yavuz, Ömer
    This study demonstrated the efficacy of leftover orange peel in removing Pb2+ ions from aqueous solutions. The effects of contact time, starting metal ion concentration, and pH on adsorption effectiveness were investigated. A starting concentration of 800 mg/L, a contact time of 90 minutes, and a solution pH of 4.32 were found to be the best working conditions for the removal of the Pb2+ ion. In order to examine the surface characteristics of the orange peel, SEM, energy dispersion spectroscopy, and Fourier transform infrared spectroscopy were all used (FT-IR). The outcomes showed that the isotherm data was sufficient for the Langmuir isotherm model, which deals with chemical adsorption and the likely irreversibility of the process. The Pb2+ ion's adsorption capacity was found to be 35.842, 35.714, and 35.087 mg/g at 318, 308, and 298 K, respectively. Pseudo-second order, which had the highest coefficient of regression and best described the kinetic data for Pb2+ adsorption. Thermodynamic investigations revealed that the removal of the Pb2+ ion from orange peel was a natural and exothermic process. Due to its great taking away capability, leftover orange peel has been discovered to be an effective and promising material for the absorption of Pb2+ ions from the aqueous environment. It is also simple to get and inexpensive.
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    Nitrogen? and oxygen?doped carbon particles produced from almond shells by hydrothermal method for efcient Pb(II) and Cd(II) adsorption
    (Springer Science and Business Media, 2023) Saka, Cafer; Teğin, İbrahim; Kahvecioğlu, Kübra; Yavuz, Ömer
    In this study, a two-step method was applied to obtain an efective adsorbent for cadmium (Cd) (II) and lead (Pb)(II) adsorption. The frst stage includes the production of activated carbon (AC) from almond shells, which is agricultural waste, by microwave heating and potassium hydroxide (KOH) chemical agent. The second stage includes nitrogen and oxygen doping by hydrothermal heating treatment of the obtained ACs with nitric acid. The obtained materials were characterized by thermogravimetric/diferential thermal analyser (TG–DTA); Fourier transform infrared spectroscopy (FTIR); scanning electron microscope (SEM); energy-dispersive spectroscopy (EDS); C, H, N, S elemental analysis; and nitrogen adsorption analyses. The adsorption performance, mechanism, kinetics, and thermodynamics of nitrogen- and oxygen-doped activated carbons were evaluated. The obtained isotherm and kinetic results showed that the adsorption of Cd (II) and Pb (II) on nitrogen- and oxygen-doped ACs followed Langmuir isotherm and pseudo-second-order kinetics. The adsorption capacity values (Qm) obtained for Cd (II) and Pb (II) adsorption were 106.38 mg/g and 76.33 mg/g, respectively.
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    Recovery of copper, cobalt, nickel, cadmium, zinc and bismuth from electrolytic copper solution
    (1998) Aydın, Fırat; Ziyadanoğulları, Berrin; Yavuz, Ömer; Ziyadanoğulları, Recep
    An electrolytic Copper Solution (ECS) was electrolyzed using platinum electrodes. Copper was obtained in solid form. In order to precipitate Cd(II), Bi(III), As(III), Sb(III) and the rest of the Cu(II) ions, $H_2S$ gas was passed through the remaining solution. The remaining solution was evaporated to obtain metal sulphates. The sample containing metal sulphates was roasted at temperatures between 550 and 800 °C. Cobalt, nickel and zinc in the solid sample remained in the form of metal sulphates, while the iron in the sample.was converted into Fe2Û3. This solid sample was dissolved in water and filtered in order to crystallize the $NiSO_4$. As a result of crystallization, a maximum yield of 86.2 % was obtained. The solid containing metal sulphides (CuS, CdS, $Bi_2S_3$ and $Sb_2S_3$) was roasted at 600° C for 3 hours. The roasted sample was dissolved in water and filtered. It was determined that the conversion of CuS into $CuSO_4$ occurred, together with the conversion of CdS and $Bi_2S_3$ into CdO and $Bi_2S_3$. The samples containing CdO and $Bi_2S_3$ were then leached with 0.5 M $H_2SO_4$ solution at 50° C for one hour. The extraction yield was 97%.
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    Removal of cadmium from aqueous solution by a soil containing magnesite
    (2004) Ziyadanoğulları, Berrin; Yavuz, Ömer; Aydın, Fırat; Aydın, Işıl; Bingöl, Hasan
    Removal of Cd (II) from aqueous solution by a soil containing magnesite and thermal activated soil containing magnesite was investigated. Maximum activation temperature was determined at 700°C for 2 h and maximum adsorption capacities were determined as 4.20 mg/g for natural magnesite, 38.91 mg/g for thermal activated magnesite at 25°C respectively. Equilibrium contact time of cadmium was determined for 2 h. Adsorption of Cd (II) on soil containing magnesite conforms to Langmuir's isotherm.
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    Sulu Çözeltilerden Pb2+ İyonlarının Uzaklaştırılmasında Atık Portakal Kabuklarının Kullanılması: Kinetik ve Termodinamik Çalışmalar
    (2023) Altunkaynak, Yalçın; Canpolat, Mutlu; Yavuz, Ömer
    Bu çalışmada, Pb2+ iyonlarının sulu çözeltilerden uzaklaştırılmasında atık portakal kabuğunun (APK) etkin bir şekilde değerlendirilmesi ve geri dönüşüme kazandırılması anlatılmaktadır. Adsorpsiyon verimliliği için; metal iyonu başlangıç derişimi, temas süresi, pH etkisi gibi farklı parametrelerin sonuçları incelendi. Pb2+ iyonunun uzaklaştırılmasında en uygun çalışma koşulları; metal iyonu başlangıç derişimi 800 mg/L, temas süresi 90 dakika ve çözelti pH'ı 4,32 olarak belirlendi. APK’nın yüzey özellikleri, Fourier dönüşümlü kızılötesi spektroskopisi (FTIR), taramalı elektron mikroskobu (SEM) ve enerji dağılım spektroskopisi ile araştırıldı. Elde edilen veriler (izoterm verileri) incelendiğinde, işlemin olası tersinmezliğine ve kimyasal adsorpsiyona karşılık gelen Langmuir izoterm modeline uygun olduğunu gösterdi. 298, 308 ve 318 K'de Pb2+ iyonu için adsorpsiyon kapasitesi sırasıyla 35,842, 35,714 ve 35,087 mg/g olarak hesaplandı. En iyi kinetik veriler, Pb2+ adsorpsiyonu için en yüksek regresyon katsayısına sahip yalancı ikinci dereceden denklem ile tanımlandı. Termodinamik çalışmalar, APK kullanılarak Pb2+ iyonlarının uzaklaştırılması işleminin doğal ve endotermik bir süreç olduğunu gösterdi. APK 'nın yüksek uzaklaştırma kapasitesi, kolay bulunması ve ucuz olması nedeniyle sulu ortamdan Pb2+ iyonlarının uzaklaştırılmasında etkili ve umut verici bir malzeme olduğu tespit edildi.
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    The Characterization of Silver Nanoparticles Synthesized From Prunus spinosa Fruit and Determination of Antimicrobial Effects on Some Food Pathogens
    (RDCONF, 2021) Atalar, Mehmet Nuri; Baran, Ayşe; Hatipoğlu, Abdulkerim; Baran, M.firat; Yavuz, Ömer; Aktepe, Necmettin; Keskin, Cumali
    Bu çalışmada, gümüş nanopartiküller (AgNP'ler) Prunus spinosa (PS) meyve özütü kullanılarak kolay, düşük maliyetli ve çevre dostu bir şekilde sentezlendi. Ultraviyole (UV)-görünür Spektrofotometre analiz verilerine göre, nanokristaller 438.3 nm'de karakteristik bir tepe noktası gösterdi. Alan Emisyon Taramalı Elektron Mikroskobu (FE-SEM), Transmisyon Elektron Mikroskobu (TEM) ve Atomik Güç Mikroskopisi (AFM) analizleri, biyosentezlenen AgNP'lerin morfolojik yapılarının küresel olduğunu ortaya koydu. XRD analizi sonuçlarına göre AgNP'lerin kristal yapılarının kübik olduğu belirlendi. Nanopartiküllerin boyutu, Debye-Scherrer denklemi ile 29,34 nm olarak hesaplandı. Sentezlenen nanomalzemenin zeta boyutu 117.4 nm olarak ölçülmüştür. AgNP’lerin gıda patojenleri olan Bacillus subtilis, Pseudomonas aeruginosa, Staphylococcus aureus ATCC 29213, Escherichia coli ATCC25922 ve Candida albicans üzerindeki inhibisyon etkileri Minimum İnhibitör Konsantrasyon (MİK) yöntemiyle ortaya konuldu.