Browsing by Author "Kilic, Necla Caliskan"

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Adsorption of Uranium (Vi) From Aqueous Solutions Using Boron Nitride/Polyindole Composite Adsorbent
(Wiley, 2024) Emre, Deniz; Zorer, Ozlem Selcuk; Bilici, Ali; Budak, Erhan; Yilmaz, Selehattin; Kilic, Necla Caliskan; Sogut, Eda Gokirmak
Turbostratic boron nitride (tBN) surface is modified with polyindole (PIn) by a facile polymerization technique and the uranyl adsorption efficiency of this mesoporous hybrid is investigated. The successful surface modification is confirmed by FT-IR, Raman, XRD, TEM, SEM, EDX, EDS mapping XPS, BET, and zeta potential techniques. The batch experiments are performed in various temperatures (T), contact times (t), pH, and initial solution concentrations (C-0) to evaluate its adsorption performance. The optimum adsorption performance is achieved at pH = 5.0-5.5, T = 307 K, t = 10 min, C-0 = 18 mg L-1. These experimental results are evaluated using Freundlich, Redlich-Peterson, and Langmuir isotherm models, which presents equivalent regression coefficients. Maximum adsorption capacity (q(m)) of the nanoadsorbent (tBN/PIn), determined by the Langmuir isotherm, is 315.29 mg g(-1). The adsorption kinetics of uranyl ions on tBN/PIn are in harmony with the pseudo-second order model. tBN/PIn nanoadsorbent provides high adsorption efficiency even at exceptionally low UO22+ concentration range (4-40 mg L-1) and low adsorbent mass (0.005 g). XPS analysis results show that 0.05% of uranium is adsorbed on tBN/PIn via mainly U-O coordination. The results of present study demonstrate that tBN/PIn can a potential adsorbent for removing uranium from aqueous solutions.
An Archaeometric Study of Provenance and Firing Technology of Halaf Pottery From Tilkitepe (Eastern Turkey)
(Univ Agean, dept Mediterranean Stud, 2017) Kilic, Necla Caliskan; Kilic, Sinan; Akgul, Hulya Caliskan
The approximation of the raw material source as well as the minimum and maximum firing temperatures in the pottery production technology can be determined depending on the mineralogical and chemical changes in the ceramic components. For the determination various analytical techniques are used such as Xray diffraction (XRD), thermal analysis (TGA-DT), Scanning electron microscope (SEM), X-ray fluorescence spectrometry (XRF) and inductively coupled plasma (ICP). In this paper the possible clay resources of Halaf pottery from Tilkitepe is required to determine. The analyzed pottery fragment and the clay samples were collected around the mound. Experimental studies were carried out at temperatures of 600 degrees C, 700 degrees C, 800 degrees C and 900 degrees C. The results show that the Halaf type ceramic piece from the mound is most probably made using local clay sources in the region and fired at temperatures below 800 degrees C under oxidation conditions.
The Effect of Mercapto-Functionalization of Thermo-Acid Activated Diatomite for Dye Removal From Aqueous Solutions
(Taylor & Francis Ltd, 2022) Sogut, Eda Gokirmak; Kilic, Necla Caliskan
For the adsorption of malachite green (MG), 'purified by thermo-acid (HCl) diatomite' (D-TA) and its derivative '3-mercaptopropyltrimethoxysilane functionalised diatomite' (DTA-MTMS) were prepared as adsorbent and the effects of thermo-acid activation and surface functional groups on adsorption were investigated. Many acids dissolve certain substances in diatomite and change their chemical composition. Thermo-acid treatment and silane-modified diatomite fractions were characterised byBrunauer-Emmett-Teller (BET), scanning electron microscope (SEM-EDS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and thermal analysis (TG-DTA). The effects of contact time, solution pH, temperature and initial dye concentration on adsorption were investigated. Equilibrium isotherms are defined using nonlinear Langmuir, Freundlich, Dubinin - Radushkevich (D - R) and Sips adsorption isotherm equations. Isotherm data for both adsorbents are best fitted on the Freundlich and Sips model. The q(max) values determined from the Sips model are 18.8415 mgg(-1) and 21.4713 mgg(-1) for D-TA and DTA-MTMS, respectively. It was determined that DTA-MTMS performed better than D-TA for MG adsorption. The results showed that MG adsorption was compatible with the pseudo-second-order (PSO) kinetic model. From the adsorption energy value (E < 8 kJ mol(-1)), it was confirmed that physical adsorption was dominant in the adsorption process. The nature of the sorption process is exothermic and spontaneous (due to negative values Delta H degrees and Delta G degrees). The results of the study showed that prepared D-TA and synthesised DTA-MTMS can be considered as an economical and promising adsorbent in removing organic dyes from wastewater.
Enhancement of Adsorption Capacity of Reduced Graphene Oxide by Sulfonic Acid Functionalization: Malachite Green and Zn (Ii) Uptake
(Elsevier Science Sa, 2020) Sogut, Eda Gokirmak; Karatas, Yasar; Gulcan, Mehmet; Kilic, Necla Caliskan
Graphene oxide (GO) was synthesized according to the Hummers' method developed to remove some impurities such as malachite green dye and Zn (II) metal ion from aqueous solutions. However, due to the problem of dispersion in water, graphene oxide surface is generally functionalized or composites are prepared with different materials. For this reason, the produced graphene oxide is functionalized with sulfanilic acid to obtain reduced sulfonated graphene oxide (rGO-SO3H). For the characterization of materials, DR/UV-vis, Raman, FT-IR, SEM and SEM-EDX mapping techniques were used. Also, reduced graphene oxide (rGO) was evaluated as a comparative example in adsorption. Effect of parameters such as pH, initial concentration and temperature on the removal of metal ions and dye was studied. Equilibrium was achieved in 90 min. The highest percentage removal of rGO and rSGO was observed at pH = 7. Equilibrium isotherms are defined using nonlinear Langmuir, Freundlich, Dubinin - Radushkevich (D - R) and Sips adsorption isotherm equations. Maximum adsorption capacities were determined as 588.23 mg g 1 and 1111.11 mg g(-1) for malachite green, 166.66 mg g(-1) and 322.58 mg g(-1) for Zn (II), respectively for rGO and rGO-SO3H. Kinetic experimental results fit well with the pseudo-second order model for both dye and metal ion; coefficients of determination were close to 1. Thermodynamic studies showed that the adsorption was spontaneous and the adsorption processes were controlled by a physical mechanism.
Methylene Blue Adsorption From Aqueous Solution by Functionalized Perlites: an Experimental and Computational Chemistry Study
(desalination Publ, 2021) Sogut, Eda Gokirmak; Ergan, Erdem; Kilic, Necla Caliskan; Donmez, Hakan; Akbas, Esvet
In this study, 3-aminopropyltrimethoxy-silane (3-APTMS) and 3-mercaptopropyltrimethoxy-silane (3-MPTMS) were used to functionalize perlite in order to increase the adsorption capacity of methylene blue (MB). These materials were characterized by X-ray diffraction, X-ray fluorescence, Fourier transform infrared spectroscopy, scanning electron microscopy, and thermal (thermogravimetry/ differential thermal analysis) analyzes. The performance of perlite and functionalized derivatives was tested by adsorption of MB in a batch system under a variable pH (2-11) and initial MB concentration (10-60 mg L-1). Nonlinear and linear Langmuir, Freundlich, Dubinin-Radushkevich (D-R), and Sips adsorption equations were applied to define equilibrium isotherms. The maximum dye sorption was found to be at a pH of 11.0 (96.44% for P-A, 96.51% for P-APTMS, and 96.73% for P-MPTMS). The adsorption capacity for the dye was found to be 4.9445, 5.2014, and 5.3112 mg g(-1) for P-A, P-APTMS, and P-MPTMS, respectively, at 298 K. The adsorption kinetics was best described by the pseudo-second-order model. The obtained results confirm that amino and mercapto functional groups have positive effects on the adsorption of methylene blue by the adsorbents used in this work. Quantum chemical analysis supported better adsorption of methylene blue dye on amine and mercapto-functionalized perlite surfaces than the unmodified surface and the most suitable site for MB adsorption was suggested by Fukui function analysis.
Porous Graphitic Carbon Nitride Nanosheets Coated With Polyfluorene for Removal of Malachite Green and Methylene Blue Dyes and Cu (Ii) Ions
(Elsevier Science Sa, 2022) Sogut, Eda Gokirmak; Emre, Deniz; Bilici, Ali; Kilic, Necla Caliskan; Yilmaz, Selehattin
Dyes and heavy metal ions are of great interest for environmental studies as they are common pollutants in industrial applications. Therefore, development of innovative adsorbents has received tremendous interest in wastewater treatment studies. In this study, a new hybrid adsorbent (g-C3N4/AFP) was prepared by modifying porous graphitic carbon nitride surface (g-C3N4) with 2-amino fluorene polymer (AFP) and investigated its adsorptive behaviour for removal of representative dyes and heavy metal from aqueous solution. Experimental data obtained from batch tests were analysed using two parameters (Freundlich, Langmuir and Dubi-nin-Radushkevich) and three parameters (Sips) isotherm models. Langmuir isotherms were the best model to describe the experimental results of Methylene blue (MB) and Malachite green (MG) dye adsorptions, while Freundlich isotherms were the best for Cu (II) ions. Sips isotherm model was found to have the highest regression coefficient (>= 0.99) among the two-parameters isotherms studied. The maximum adsorption capacities of g-C3N4 and g-C3N4/AFP were found to be 226.88 and 327.83 for MG, 85.73 and 221.85 for MB and 184.51 and 452.19 mg g(-1) for Cu (II), respectively. This increase in adsorption capacity can be explained by the improved textural properties of the new hybrid adsorbent and the presence of multiple functional groups in its structure. A possible adsorption mechanism was suggested using FTIR and pH(pzc) data.