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Öğe Adsorption of Cu2+ and Pb2+ ion on dolomite powder(ELSEVIER SCIENCE BV, 2009) Pehlivan, Erol; Ozkan, Ali Mujdat; Dinc, Salih; Parlayici, SerifeNatural Turkish dolomite was shown to be effective for removing Cu2+ and Pb2+ from aqueous solution. Selected information on pH, dose required, initial metal concentration, adsorption capacity of the raw dolomite powder was evaluated for its efficiency in adsorbing metal ions. Dolomite exhibited good Cu2+ and Pb2+ removal levels at all initial metal amount tested (0.04-0.32 mmol, 20 mL). It is important to note that the adsorption capacities of the materials in equilibrium vary, depending on the characteristics of the individual adsorbent, the initial concentration of the adsorbate and pH of the solution. One hour was enough for the removal of metal ions from (0.2 mmol in 20 mL) aqueous solution. Effective removal of metal ions was demonstrated at pH values of 5.0. The adsorptive behavior of dolomite was described by fitting data generated from the study of the Langmuir and Freundlich isotherm models. The adsorption capacity of dolomite was found as 8.26 mg for Cu2+ and 21.74 mg for Pb2+, respectively, from the calculation of adsorption isotherm equation. More than 85% of studied cations were removed by dolomite from aqueous solution in single step. The mechanism for cations removal by dolomite includes surface complexation and ion exchange. (C) 2009 Elsevier B.V. All rights reserved.Öğe Natural biosorbents (garlic stem and horse chesnut shell) for removal of chromium(VI) from aqueous solutions(SPRINGER, 2015) Parlayici, Serife; Pehlivan, ErolThe biosorption of Cr(VI) by the garlic stem (GS)-Allium sativum L. and horse chesnut shell (HCS)-Aesculus hippocastanum plant residues in a batch type reactor was studied in detail for the purpose of wastewater treatment. The influence of initial Cr(VI) concentration, time, and pH was investigated to optimize Cr(VI) removal from aqueous solutions and equilibrium isotherms and kinetic data. This influence was evaluated. The adsorption capacity of the GS and the HCS for Cr(VI) was determined with the Langmuir and Freundlich isotherm models, and the data was fitted to the Langmuir. The adsorption capacity of the GS and the HCS was found to be 103.09 and 142.85 mg/g of adsorbent from a solution containing 3000 ppm of Cr(VI), respectively. The GS's capacity was considerably lower than that of the HCS in its natural form. Gibbs free energy was spontaneous for all interactions, and the adsorption process exhibited exothermic enthalpy values. The HCS was shown to be a promising biosorbent for Cr(VI) removal from aqueous solutions.Öğe Removal of chromium (VI) using activated carbon-supported-functionalized carbon nanotubes(SPRINGER HEIDELBERG, 2015) Parlayici, Serife; Eskizeybek, Volkan; Avci, Ahmet; Pehlivan, ErolThe powdered activated carbon (AC) supported by carbonaceous nano-adsorbents were examined to remove hexavalent chromium [Cr(VI)] from aqueous solution The adsorption behaviour of micro-level concentration of Cr(VI) on those nano-adsorbents was investigated as a function of the experimental conditions such as the contact time, the pH, the dosage of adsorbent, and the initial concentration of Cr(VI). The structural characterization of the adsorbents was accomplished by Fourier transform infrared spectroscopy and scanning electron microscopy. Adsorption isotherms including Freundlich and Langmuir have been applied to study the equilibrium of the adsorption behaviour and identify the adsorption capacity of the activated carbon-functionalized multiwalled carbon nanotubes (AC/f-MWCNTs) and activated carbon-functionalized carbon nanospheres (AC/f-CNSs). Langmuir isotherm model showed that the adsorption process was monolayer type under working with an adsorption capacity of 113.29 and 105.48 mg/g, respectively, for AC/f-MWCNTs and (AC/f-CNSs).Öğe Removal of hexavalent chromium using polyacrylonitrile/titanium dioxide nanofiber membrane(TAYLOR & FRANCIS INC, 2016) Parlayici, Serife; Yar, Adem; Avci, Ahmet; Pehlivan, ErolPolyacrylonitrile/titanium dioxide nanofiber (PAN/T-nF) membrane was prepared with TiO2 nanoparticles which dispersed into polyacrylonitrile (PAN) matrix with ultrasonic probe in ultrasonic bath. The amount of TiO2 loaded in the membrane was 1 and 3wt% to explore the activity of membranes in the adsorption process. PAN/T-nF membrane was prepared by electrospinning technique. The potential of the prepared PAN/T-nF membrane was investigated for the removal of Cr(VI) from aqueous solutions. The adsorption equilibrium was investigated in the batch process. The adsorption process displayed pH dependence and the maximum Cr(VI) adsorption took place at pH 2. The equilibrium was attained at a contact time of 180min and Langmuir adsorption model was suitable for the adsorption isotherms. Maximum adsorption capacities 245.3 and 280.4mg Cr(VI)/g were calculated for 1 and 3% PAN/T-nF membrane, respectively. The adsorption of Cr(VI) on PAN/T-nF was related to the mechanism of surface complexation, coordination, and electrostatic attraction. This new fabrication method for PAN/T-nF membranes showed an excellent thermal stability that can persist up to 400 degrees C and has a big capacity for Cr(VI) ion.Öğe Removal of metals by Fe3O4 loaded activated carbon prepared from plum stone (Prunus nigra): Kinetics and modelling study(ELSEVIER SCIENCE BV, 2017) Parlayici, Serife; Pehlivan, ErolThis study investigates the adsorption of Cu(II) and Pb(II) ions onto magnetic-plum stone activated carbon (m-PSAC). Plum stone-activated carbon (PSAC) was produced by chemical activation of plum stone (PS) with phosphoric acid (H3PO4\) in N-2\ inert atmosphere. The effects of activator ratio, activation temperature, and impregnation temperature were examined. m-PSAC was prepared by co-precipitation method which is a combination of PSAC with Fe2+:Fe3+ salts. The prepared m-PSAC was characterized by scanning electron microscopy (SEM) and Fourier Transform infrared spectrophotometer (FT-IR). Then m-PSAC was used for the removal of Cu(II) and Pb(II) ions from aqueous solutions. The effects of initial pH, the amount of m-PSAC, temperature, contact time, and the initial concentration of Cu(II) and Pb(II) were investigated during the equilibrium and kinetics studies. Adsorption isotherms for the Cu(II) and Pb(II) on m-PSAC was determined and correlated with Langmuir, Freundlich, Scatchard and D-R isotherm equations. The adsorption data showed that adsorption of Cu(II) and Pb(II) was fitted by Langmuir isotherm model and pseudo-second-order kinetics model. Under the optimized conditions, maximum adsorption capacities of Cu(II) and Pb(II) ions determined by Langmuir model were enhanced 48.31 and 80.65 mg/g, respectively. Thermodynamic parameters such as Delta G degrees, Delta H degrees, Delta S degrees, E-a were calculated and the interaction of metals with m-PSAC was found to be exothermic and spontaneous in nature. (C) 2017 Elsevier B.V. All rights reserved.Öğe Utilization of eco-friendly gelatin for Cr(VI) adsorption(DESALINATION PUBL, 2017) Parlayici, Serife; Karakuzu, Emre; Baybara, Ahmet S.; Tuna, Kubra; Pehlivan, ErolGelatin is a biodegradable, biocompatible, non-toxic, non-carcinogenetic and natural polymeric derivative of proteins and peptides. In this article, we applied gelatin as an eco-friendly biosorbent assay for removal of the Cr(VI). The behavior and cogency of gelatin as a biosorbent for interaction with Cr(VI) in aqueous solution was presented. The excellent adsorption properties of gelatin and modified gelatin were confirmed by measuring the capacity of Cr(VI). The batch adsorption model was applied as a function of time, adsorbent dosage, and pH to examine biosorbent's activity. Bio-sorbents showed an excellent adsorption capacity at pH 3.0. The maximum adsorption capacities was found to be 62.50 and 43.86 mg/g of modified and raw gelatin for Cr(VI) ion respectively. The applicability of Freundlich and Langmuir adsorption models were investigated for Cr(VI)-biosorbent interaction. Equilibrium data followed Langmuir adsorption isotherm excellently.
