Ömer Yavuz - Academia.edu (original) (raw)

Papers by Ömer Yavuz

Düzce Üniversitesi Bilim ve Teknoloji Dergisi

Bu çalışmada, Pb2+ iyonlarının sulu çözeltilerden uzaklaştırılmasında atık portakal kabuğunun (AP... more 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 içi...

Europan journal of science and technology, Jan 2, 2022

In this study, silver nanoparticles (AgNPs) were synthesized using Prunus spinosa (PS) fruit extr... more In this study, silver nanoparticles (AgNPs) were synthesized using Prunus spinosa (PS) fruit extract in an easy, low-cost and environmentally friendly way. According to the Ultraviolet (UV)-visible Spectrophotometer analysis data, the nanocrystals showed a characteristic peak at 438.3 nm. Field Emission Scanning Electron Microscopy (FE-SEM), Transmission Electron Microscopy (TEM), and Atomic Force Microscopy (AFM) analyzes revealed that the morphological structures of the biosynthesized AgNPs were spherical. According to the results of XRD analysis, it was determined that the crystal structures of AgNPs were cubic. The size of the nanoparticles was calculated as 29,34 nm by the Debye-Scherrer equation. The zeta size of the synthesized nanomaterial was measured as 117.4 nm. Inhibitory effects of AgNPs on food pathogens Bacillus subtilis, Pseudomonas aeruginosa, Staphylococcus aureus ATCC 29213, Escherichia coli ATCC25922 and Candida albicans were revealed by the Minimum Inhibitory Concentration (MIC) method.

Archives of Agronomy and Soil Science, Aug 1, 2004

Page 1. REMOVAL OF CADMIUM FROM AQUEOUS SOLUTION BY A SOIL CONTAINING MAGNESITE BESEITIGUNG VON C... more Page 1. REMOVAL OF CADMIUM FROM AQUEOUS SOLUTION BY A SOIL CONTAINING MAGNESITE BESEITIGUNG VON CADMIUM AUS WA¨SSRIGER LO¨SUNG DURCH EINEN MAGNESIT ENTHALTENDEN BODEN ...

Polish Journal of Environmental Studies, 2006

Dyestuff production units and dyeing units have always had a pressing need for techniques that al... more Dyestuff production units and dyeing units have always had a pressing need for techniques that allow economical pre-treatment for colour in the effluent. The effectiveness of adsorption for dye removal from wastewaters has made it an ideal alternative to other expensive treatment options. Removal of direct dyes [direct yellow 50 (DY50), direct red 80 (DR80) and direct blue 71(DB71)] from an aqueous solution by different adsorbents such as activated carbon, raw kaolinite and montmorillonite was investigated. The adsorption isotherm data were fitted to the Langmuir isotherm. Parameters of the Langmuir isotherm have been determined using the adsorption data. Adsorption capacity of RAC (commercial activated carbon), HAC (activated carbon obtained from shell of hazelnut), KC (raw kaolinite) and MC (montmorillonite) increased in the following order: DY50 > DR80 > DB71, DB71>DR80>DY50, DR80>DB71>DY50 and DB71>DR80 (DY50 showed no absorption) for the direct dyes, respectively.

Niğde Ömer Halisdemir Üniversitesi mühendislik bilimleri dergisi, Aug 9, 2022

Endüstriyel atıklardan ağır metallerin uzaklaştırılması bilim insanlarının çözüm aradığı en öneml... more Endüstriyel atıklardan ağır metallerin uzaklaştırılması bilim insanlarının çözüm aradığı en önemli konulardan biridir. Bu araştırma, sulu çözeltilerden Pb 2+ 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. Pb 2+ 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. Pb 2+ 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 Pb 2+ iyonunun uzaklaştırılmasının doğal ve endotermik olduğunu göstermiştir. MT'nin sahip olduğu yüksek adsorpsiyon kapasitesi, ucuz ve kolay bulunabilmesi gibi özelliklerinden dolayı Pb 2+ iyonlarının sulu ortamdan uzaklaştırılmasında etkili ve gelecek vaat eden bir malzeme olduğu tespit edilmiştir. One of the most pressing concerns that scientists are attempting to solve is the removal of heavy metals from industrial waste. The effectiveness of Midyat stone (MS) for the adsorption of Pb 2+ ions from aqueous solutions is investigated in this study. The effects of numerous variables on adsorption effectiveness, such as contact duration, initial metal ion concentration, and pH, were studied in the study. Scanning electron microscopy, energy dispersion spectroscopy, and Fourier transform infrared spectroscopy were used to analyze the surface properties of MS. Under the most favorable working conditions for the removal of the Pb 2+ ion, the starting concentration, contact duration, and solution pH were determined to be 800 mg/L, 90 minutes, and 4,23, respectively. The results showed that the isotherm data fit the Langmuir isotherm model, and the kinetic data fit the pseudo-second-order (PSO) model. At 298, 308, and 318 K, the adsorption capacity of the Pb 2+ ion was determined to be 129.87 mg/g, 178.57 mg/g, and 188.68 mg/g, respectively. The elimination of Pb 2+ ions by MS was shown to be natural and endothermic in thermodynamic analyses. Because of its features, such as high adsorption capacity, low cost, and ease of availability, it has been determined that MS is an effective and promising material for removing Pb 2+ ions from the aqueous environment.

Fen ve mühendislik bilimleri dergisi, Jun 30, 2022

Bu çalışmada, sulu çözeltilerden Cu 2+ iyonlarını uzaklaştırmak amacıyla atık portakal kabuğu (AP... more Bu çalışmada, sulu çözeltilerden Cu 2+ iyonlarını uzaklaştırmak amacıyla atık portakal kabuğu (APK) değerlendirildi. Portakal kabuğunun karakterizasyonu, yüzey morfolojisi için taramalı elektron mikroskobu-enerji dağılım spektroskopisi (SEM-EDS) ve yüzey fonksiyonel grupları için Fourier dönüşümü kızılötesi spektroskopisi (FT-IR) ile incelendi. Farklı sıcaklıklarda bulunan kinetik değerler yalancı birinci derece, yalancı ikinci derece, Elovich ve parçacık içi difüzyon modeli denklemlerine uygulanmıştır. Adsorpsiyon sürecini daha iyi anlamak için Langmuir, Freundlich, Temkin ve Dubinin-Radushkevich (D-R) adsorpsiyon izotermlerinin uygulanabilirliği değerlendirildi. Bakırın uzaklaştırılması yalancı ikinci dereceden kinetik model ile Langmuir izoterm modelini takip etti. Cu 2+ için uzaklaştırma kapasitesi 298, 308 ve 318 K'de sırasıyla 7.74, 7.98 ve 8.84 mg/g olarak elde edilmiştir. Cu 2+ iyonlarının Gibbs serbest enerjisi (ΔG o), adsorpsiyon ısısı (ΔH o) ve entropisi (ΔS o) için termodinamik veriler sırasıyla-16.76 kj/mol, 29.43 kj/mol ve 154.79 j/mol olarak bulundu.

Journal of The Iranian Chemical Society, Nov 30, 2021

Activated carbon prepared from hazelnut shells was used to remove Co(II) from aqueous solution by... more Activated carbon prepared from hazelnut shells was used to remove Co(II) from aqueous solution by adsorption. Batch-mode adsorption experiments were carried out varying parameters such as the initial metal ion concentration (13.30-45.55 mg/l), agitation speed (50-200 rpm), pH (2-8), temperature (293-323 K) and particle size (0.80-1.60 mm). The kinetics of the adsorption of Co(II) followed the pseudo-second-order equation, being pHdependent since the removal rate increased with the pH value of the aqueous solution. The adsorption equilibrium data obeyed the Langmuir isotherm. The adsorption capacity (Q 0) calculated from the Langmuir isotherm was 13.88 mg Co(II)/g carbon at 303 K employing a pH value of 6 and a particle size of 1.00-1.20 mm. The thermodynamic parameters evaluated for the carbon revealed that the adsorption of Co(II) was endothermic in nature.

Water Research, Feb 1, 2003

The removal of some heavy metals such as Mn(II), Co(II), Ni(II), and Cu(II) from aqueous solution... more The removal of some heavy metals such as Mn(II), Co(II), Ni(II), and Cu(II) from aqueous solution is studied using a raw kaolinite. The sorption of these metals on kaolinite conformed to linear form of Langmuir adsorption equation. Langmuir C m constants for each metal were found as 0.446 mg/g (Mn), 0.919 mg/g (Co), 1.669 mg/g (Ni), 10,787 mg/g (Cu) at 251C, respectively. Also, kinetic and thermodynamic parameters such as enthalpy (DH), free energy (DG) and entropy (DS) were calculated and these values show that adsorption of heavy metal on kaolinite was an endothermic process and the process of adsorption was favoured at high temperatures.

Particulate Science and Technology, Sep 23, 2021

Gazi university journal of science part a:engineering and innovation, Mar 28, 2023

In this study, the adsorption kinetics of Cu(II) and Ni(II) ions in the aqueous medium of the nat... more 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.

Journal of Nanomaterials, Feb 27, 2022

Introduction. Fighting against cancer and antibiotic resistance are important challenges of healt... more 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 ınfrared 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

Frontiers in Bioengineering and Biotechnology, Mar 7, 2022

Using biological materials to synthesize metallic nanoparticles has become a frequently preferred... more 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

International Journal of Environmental Science and Technology

This study investigates a low-cost and economical raw and heat-treated clay sample as a potential... more This study investigates a low-cost and economical raw and heat-treated clay sample as a potential adsorbent for a higher uptake of Cu(II), Pb(II) and Cd(II) ions from aqueous solutions. The characterization of the obtained raw and modified clay materials, X-ray fluorescence spectroscopy, thermogravimetric analysis, X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy were carried out. Compared with the raw clay sample, the adsorption ability of metal ions with the heat-treated clay adsorbent was significantly improved. The effects of calcination temperature, initial metal concentration, solution temperature and contact time on adsorption capacity were investigated. Adsorption data were tested with Langmuir and Freundlich models, and the Langmuir model showed a relatively better fit. The adsorption capacities for Cu (II), Pb (II) and Cd (II) ions were found to be 156.25 mg/g, 172.40 mg/g and 9.15 mg/g, respectively. The adsorption data for heavy metal ions confirmed the pseudo-second-order kinetic model. Heat-treated clay samples showed remarkable adsorption efficiency for heavy metal removal from aqueous systems; therefore, it can be considered as a competent and potential adsorbent for heavy metal removal.

In this study, cold plasma treatment was applied for the surface modification of kaolin adsorbent... more In this study, cold plasma treatment was applied for the surface modification of kaolin adsorbent to improve the removal of methylene blue (MB) from aqueous solution. To achieve the aim, the conditions for adsorption, including cold plasma application time, initial dye concentration, and pH were investigated with respect to the removal efficiency of MB. The changes of the surface property before and after cold plasma treatment were discussed. The maximum adsorption capacity of MB compared with untreated raw kaolin increased from 19.60 to 51.02 mg/g (up to approximately 2, 5-fold) after modification by cold plasma. The experimental data were analyzed using pseudo first-order and second-order kinetic models. The surface properties of kaolin treated with cold plasma were investigated with scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and point of zero charge (pzc) measurements to understand the adsorption mechanism

Bulletin of Environmental Contamination and Toxicology, 2004

The macrofungi specimens were collected and identified from locations around Batman province of T... more The macrofungi specimens were collected and identified from locations around Batman province of Turkey. A group of 21 macrofungi were collected from 29 different locations and analysed for the heavy metal contents. The highest Pb and Cu levels were found in Russula rubroalba while the highest Cd level was determined for the species Agaricus xanthodermus. Fe level was maximum for the species Funalia trogii; Mn for Mycena personsii; Zn level was for Morchella esculenta and Co level was for the species Agaricus xanthodermus. The lowest Cd, Cu, Mn and Zn contents were found in Inotus hispidus.

Biomass Conversion and Biorefinery, Feb 10, 2023

Chemical Biology & Drug Design

Environmental Science and Pollution Research

Afyon Kocatepe University Journal of Sciences and Engineering

Bu çalışmada, sulu çözeltilerden Cu2+ iyonlarını uzaklaştırmak amacıyla atık portakal kabuğu (APK... more Bu çalışmada, sulu çözeltilerden Cu2+ iyonlarını uzaklaştırmak amacıyla atık portakal kabuğu (APK) değerlendirildi. Portakal kabuğunun karakterizasyonu, yüzey morfolojisi için taramalı elektron mikroskobu-enerji dağılım spektroskopisi (SEM-EDS) ve yüzey fonksiyonel grupları için Fourier dönüşümü kızılötesi spektroskopisi (FT-IR) ile incelendi. Farklı sıcaklıklarda bulunan kinetik değerler yalancı birinci derece, yalancı ikinci derece, Elovich ve parçacık içi difüzyon modeli denklemlerine uygulanmıştır. Adsorpsiyon sürecini daha iyi anlamak için Langmuir, Freundlich, Temkin ve Dubinin-Radushkevich (D-R) adsorpsiyon izotermlerinin uygulanabilirliği değerlendirildi. Bakırın uzaklaştırılması yalancı ikinci dereceden kinetik model ile Langmuir izoterm modelini takip etti. Cu2+ için uzaklaştırma kapasitesi 298, 308 ve 318 K'de sırasıyla 7.74, 7.98 ve 8.84 mg/g olarak elde edilmiştir. Cu2+ iyonlarının Gibbs serbest enerjisi (ΔGo), adsorpsiyon ısısı (ΔHo) ve entropisi (ΔSo) için termodi...