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Öğe Adsorptive removal of malachite green and Rhodamine B dyes on Fe3O4/activated carbon composite(Taylor & Francis Inc, 2017) Datta, Dipaloy; Kuyumcu, OEzge Kerkez; Bayazit, Sahika Sena; Salam, Mohamed AbdelThis study demonstrates the adsorption experiments of toxic dyes malachite green (MG) and Rhodamine B (RB) on Fe3O4-loaded activated carbon (AC). AC, which is known to be a high-capacity adsorbent, was aimed to be easily separated from aqueous media by loading it with Fe3O4. Fe3O4-loaded AC was prepared by the coprecipitation method and named magnetic activated carbon (M-AC), and the produced M-AC was characterized by x-ray diffraction (XRD), thermogravimetric analysis (TGA), and pH(pzc) analyses. MG and RB adsorption by the M-AC was performed separately by batch technique and the effects of adsorbent amount, solution pH, and initial dye concentration on the adsorption were explored. Maximum removal efficiencies were found to be 96.11% for MG and 98.54% for RB, and the Langmuir isotherm model was the most fitted isotherm model for the adsorption. The kinetic and thermodynamic studies showed that the adsorption proceeded via the pseudo-second-order kinetic model and endothermic in-nature for both dyes.Öğe Antibiotic amoxicillin removal from aqueous solution using magnetically modified graphene nanoplatelets(Elsevier Science Inc, 2016) Kerkez-Kuyumcu, Ozge; Bayazit, Sahika Sena; Salam, Mohamed AbdelThe removal of antibiotic amoxicillin (AA) from aqueous solution was investigated using magnetically modified graphene nanoplatelets (M-GNPs). M-GNPs were prepared by mixing GNPs with freshly prepared magnetite nanopartilcles, and characterized using TEM, and XRD. The characterization results revealed the homogenous distribution of the magnetite nanopartilcles over the surface of transparent platelet-like graphene platlets. The M-GNPs proved to possess superior adsorption capacity compared with the pristine GNPs and the magnetite nanopartilces. The effects of different operational parameters which affect the removal process were explored; adsorbent amounts, contact time, initial pH, temperature, and the initial concentration of AA. The results showed the great affinity of the M-GNPs toward the AA and the maximum adsorption capacity was found to be 14.10 mg g(-1). The adsorption mechanism of AA by the M-GNPs involved pi-pi stacking and electrostatic interaction. The adsorption was studied kinetically and thermodynamically, and was found to mainly follow pseudo-second-order kinetic model, and was spontaneous and exothermic in nature. (C) 2016 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.Öğe Chitosan grafted SiO2-Fe3O4 nanoparticles for removal of antibiotics from water(Springer Heidelberg, 2018) Danalioglu, Selen Tugba; Kuyumcu, Ozge Kerkez; Salam, Mohamed Abdel; Bayazit, Sahika SenaThe antibiotic wastes in environment are very dangerous for human being because of the spread of epidemics due to increasing of the antibiotic-resistant bacteria. For reducing the proliferation of these bacteria, an environmental-friendly, cheap and non-toxic adsorbent, chitosan-grafted SiO2/Fe3O4, was developed in this study. The chitosan-grafted SiO2/Fe3O4 (Chi-SiO2/Fe3O4) nanoparticles were prepared and characterised by different physical and chemical techniques such as X-ray diffraction spectroscopy (XRD), Fourier transform infrared spectroscopy (FTIR), N-2 adsorption-desorption isotherms (BET), thermogravimetric analysis (TGA), vibrating sample magnetometer (VSM), scanning electron microscopy (SEM) and zeta-potential analysis. The prepared nanoparticles were used for ciprofloxacin (CPX) adsorption from water. The nonlinear Langmuir and Freundlich isotherms were applied to experimental data. And Langmuir isotherm showed the best fit. The nonlinear pseudo-first-order and pseudo-second-order kinetic models and Weber-Morris intraparticle diffusion model were applied to kinetic data. The adsorption process followed the pseudo-second-order kinetic model. And the rate-limiting step was intraparticle diffusion step. The most suitable eluent for CPX desorption was determined as phosphate buffer solution rather than ethanol, and NaCl solution. It desorbed the 100% of CPX solution in 5h.Öğe Efficient removal of antibiotics by a novel magnetic adsorbent: Magnetic activated carbon/chitosan (MACC) nanocomposite(Elsevier, 2017) Danahoglu, Selen Tugba; Bayazit, Sahika Sena; Kuyumcu, Ozge Kerkez; Salam, Mohamed AbdelA novel adsorbent, Fe3O4/activated carbon/chitosan (MACC: Magnetic activated carbon/chitosan) was prepared by a simple coprecipitation method. MACC was characterized by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), scanning electron microscopy (SEM), vibrating sample magnetometry (VSM), and surface area analysis. MACC adsorption ability was tested for three commonly used hazardous antibiotics: ciprofloxacin, erythromycin, and amoxicillin. Langmuir isotherm model and pseudo second order kinetic model were best fitted with experimental results. Superior uptake values were found with using MACC; 90.10, 178.57 and 52631 mg/g were calculated as the theoretical adsorption capacity (g,n) using Langmuir isotherm for ciprofloxacin, erythromycin, and amoxicillin, respectively. Finally, MACC is considered as a promising magnetically separable efficient adsorbent for antibiotics removal. (C) 2017 Elsevier B.V. All rights reserved.Öğe Montmorillonit bazlı nanokiller kullanılarak kristal viyolet boyar maddesinin sulu çözeltilerden giderimi: Kinetik ve denge çalışmaları(2023) Çavuşoğlu, Ferda Civan; Bayazit, Şahika Sena; Salam, Mohamed AbdelSon yıllarda özellikle arıtılmadan farklı sektörlerden deşarj edilen atıklar nedeniyle su kirliliği büyük bir sorun haline gelmiştir. Bunlar arasında tekstil, deri, kâğıt ve kozmetik sektörlerinin kullandığı çeşitli boya atıkları da bulunmaktadır. Kristal viyolet (CV) yaygın olarak bilinen katyonik bir boyadır ve genellikle endüstrilerde renklendirici olarak kullanılır. CV boyası 1 ppb'de olduğunda insanlar ve hayvanlar için toksik olduğu bilinmektedir. Bu nedenle, endüstriyel atık suların deşarj edilmeden önce kristal viyoletden arıtılması çevre güvenliği için oldukça önemlidir. Bu araştırma, kristal viyolet boyar maddesinın sulu çözeltilerden uzaklaştırılması için düşük maliyetli bir malzeme olarak iki farklı montmorillonit bazlı nanokilin (B1 ve B2) etkinliğini değerlendirmeyi amaçlamıştır. Nanokillerin yapısal karakterizasyonları FTIR ve TGA yöntemleri kullanılarak analiz edilmiştir. CV adsorpsiyon prosesini etkileyebilecek tüm parametreler kesikli bir sistemde optimize edilmiştir. Adsorpsiyon prosesi üzerinde çeşitli faktörlerin (adsorban miktarı, temas süresi, çözelti pH’ı, farklı iyon etkisi, adsorpsiyon sıcaklığı, başlangıç boya konsantrasyonu) etkileri incelenmiştir. CV-nanokil adsorpsiyon sisteminin mekanizmasını araştırmak üzere yapılan deneylerde, adsorpsiyon kinetiğinin ve denge parametrelerinin, sırasıyla sözde ikinci dereceden kinetik modele ve Langmuir izoterm modeline daha iyi uyum sağladığını göstermiştir. B1 ve B2 adsorbanlarının maksimum adsorpsiyon kapasiteleri (qm) sırasıyla, 25oC'de 224,63 ve 45oC’de 360,30 mg/g olarak elde edilmiştir. Uygun yüzey ve CV iyon yükü kombinasyonu CV çözeltisinin düşük pH (?7) değerlerinde elde edilmiştir. Yabancı iyon olarak NaCl iyonlarının varlığı, CV adsorpsiyon kapasitesini önemli ölçüde etkilememiştir. Sonuçlar değerlendirildiğinde, incelenen montmorillonit bazlı adsorbanların, CV boyasının giderilmesinde etkili ve uygun maliyetli adsorbanlar olduğu görülmüştür.Öğe Preparation of magnetic MIL-101 (Cr) for efficient removal of ciprofloxacin(Springer Heidelberg, 2017) Bayazit, Sahika Sena; Danalioglu, Selen Tugba; Salam, Mohamed Abdel; Kuyumcu, Ozge KerkezMetal organic frameworks are widely used as adsorbent materials in recent years. In this study, the most prepared metal organic framework MIL-101 was prepared by hydrothermal method and featured magnetic property using co-precipitation method Fe3O4. Then, the prepared composite (MIL-101/Fe3O4) was first characterized using XRD, FTIR, SEM-EDS, and surface area analysis, then was used for the adsorptive removal of the most used antibiotic, ciprofloxacin (CIP). The effect of different adsorption variables which may affect the removal of CIP by MIL-101/Fe3O4 was investigated, as well as their adsorbent quantity, initial CIP concentration, pH, temperature, and contact time. The non-linear Langmuir and Freundlich isotherm were applied to experimental data. It was observed that rising solution temperature decreases adsorption efficiency, as the maximum adsorption uptake value was 63.28 mg g(-1) at 298 K and 22.93 mg g(-1) at 313 K, indicating the exothermic nature of the adsorption. The adsorption was studied kinetically and found to follow the pseudo-second-order kinetic model. The desorption of CIP from the MIL-101/Fe3O4 was investigated using three different eluents, and the results showed that phosphate-buffered solution was the most effective desorption eluent.Öğe Rapid adsorptive removal of naphthalene from water using graphene nanoplatelet/MIL-101 (Cr) nanocomposite(Elsevier Science Sa, 2017) Bayazit, Sahika Sena; Yildiz, Mahmut; Asci, Yavuz Selim; Sahin, Musa; Bener, Mustafa; Eglence, Songul; Salam, Mohamed AbdelThe study of the adsorption equilibria of naphthalene onto graphene nanoplatelet supported MIL-101 composite material (GNP/MIL-101) has been conducted. In the experimental context of this study, firstly GNP/MIL-101 was synthesized by applying hydrothermal method and characterized via FTIR, XRD, SEM, TEM and surface area analyses. The effects of GNP/MIL-101 amount, temperature and initial naphthalene concentration on the adsorption process have been investigated. Results show that the maximum removal of naphthalene was obtained as about 93% by 0.075 g GNP/MIL-101 at 298 K. The isothermal data were fitted to linear and non-linear Langmuir, Freundlich, and Temkin adsorption isotherm models and the kinetic data were fitted to Elovich and other kinetic models. Adsorption depended on initial naphthalene concentration at investigated various temperatures (298, 308, 318 K) significantly. The temperature dependence of adsorption process is associated with the changes in several thermodynamic parameters such as standard free energy (.6..G0), enthalpy(.6,H0) and entropy (.66). (C) 2017 Elsevier B.V. All rights reserved.Öğe Recovery of polyphenols from water using Zr-based metal-organic frameworks and their nanocomposites with graphene nanoplatelets(Elsevier Science Inc, 2019) Sahin, Selin; Elhussein, Elaf Abdelillah Ali; Salam, Mohamed Abdel; Bayazit, Sahika SenaIn this study, Zr-based metal organic frameworks (UiO-66) and graphene nanoplatelets UiO-66 nanocomposites (GNP/UiO-66) were prepared using acid promoted method, and used for adsorption of two different polyphenols; oleuropein and hydroxytyrosol. Different characterization techniques used for exploring the morphological and structure properties of the UiO-66 and GNP/UiO-66 nano composites. The adsorption of oleuropein and hydroxytyrosol was studied by UiO-66 and different GNP/UiO-66 nanocomposites and results showed that most of the oleuropein and hydroxytyrosol were removed from the solution in 60 min and 180 min, respectively. The kinetic modelling of adsorption was studied. The adsorption isotherms were constructed at different pH values. (C) 2019 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.Öğe Removal of ciprofloxacin from aqueous solution using humic acid- and levulinic acid- coated Fe3O4 nanoparticles(Inst Chemical Engineers, 2017) Danalioglu, Selen Tugba; Bayazit, Sahika Sena; Kerkez, Ozge; Alhogbi, Basma G.; Salam, Mohamed AbdelHumic acid (HA)- and levulinic acid (LA)-coated magnetic Fe3O4 nanoparticles were prepared and subsequently characterized using scanning electron microscopy, X-ray diffraction spectroscopy, Fourier transformer infrared spectroscopy, thermogravimetric analysis, particle size distribution analysis, and zeta-potential analysis. These magnetic nanoparticles were used for ciprofloxacin adsorption from aqueous solutions. Non-linear Langmuir and Freundlich adsorption isotherm models were used to explain the adsorption equilibria. The Langmuir adsorption capacities (q(m)) were 101.93 mg/g for HA-coated Fe3O4 and 53.76 mg/g for LA-coated Fe3O4. The appropriate contact times were 40 min for HA-coated Fe3O4 and 60 min for LA-coated Fe3O4. The adsorption rates and mechanisms were determined using pseudo-first-order and pseudo-second-order kinetic models. After the adsorption studies, the loaded nanoparticles were used for desorption studies, and their desorption kinetics were investigated. (C) 2017 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.Öğe Removal of crystal violet dye from aqueous solutions using montmorillonite-based nanoclays: Kinetic and equilibrium studies(Gazi Univ, Fac Engineering Architecture, 2023) Cavusoglu, Ferda Civan; Bayazit, Sahika Sena; Salam, Mohamed AbdelIn recent years, water pollution has become a major problem, especially due to the wastes discharged from different sectors without treatment. Among these, there are various paint wastes used by the textile, leather, paper and cosmetics sectors. Crystal violet (CV) is a widely known cationic dye and is often used as a colorant in industries. CV dye is known to be toxic to humans and animals at 1 ppb. For this reason, it is very important for environmental safety to treat industrial wastewater from crystal violet before discharge. This research aimed to evaluate the efficacy of two different montmorillonite-based nanoclays (B1 and B2) as a low-cost material for the removal of crystal violet dye from aqueous solutions. Structural characterizations of nanoclays were analyzed using FTIR and TGA methods. All parameters that could affect the CV adsorption process were optimized in a batch system. The effects of various factors (adsorbent dose, contact time, solution pH, co-existing ion effects, adsorption temperature, initial dye concentration) on the adsorption process were investigated. Experiments to investigate the mechanism of the CV-nanoclay adsorption system showed that the adsorption kinetics and equilibrium parameters fit better with the Pseudo second-order kinetic model and the Langmuir isotherm model, respectively. The maximum adsorption capacities (qm) of B1 and B2 adsorbents were obtained as 224.63 mg/g at 25 degrees C and 360.30 mg/g at 45 degrees C, respectively. A suitable combination of surface and CV ion charge was obtained at low pH values (<= 7) of the CV solution. The presence of co-existing NaCl ions did not significantly affect the CV adsorption capacity. When the results were evaluated, it was seen that the montmorillonite-based adsorbents were effective and cost-effective adsorbents for CV dye removal.
