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    Comparison of different polymeric resins for naproxen removal from wastewater
    (Elsevier Science Bv, 2017) Kurtulbas, Ebru; Bilgin, Mehmet; Sahin, Selin; Bayazit, Sahika Sena
    The polymeric resins are eco-friendly, cheap and have good surface properties. These resins were used for Naproxen (NPX) adsorption from aqueous solutions. Three different resins were chosen. These are Amberlite XAD-2, XAD-4 and XAD-16. The effects of adsorption variables were tested. The variables were selected as adsorbent quantity, NPX concentration, pH of solution, temperature and contact time. Langmuir and Freundlich isotherm models were applied to the experimental data. And it was observed that Langmuir isotherm model fitted the experimental data properly. The pseudo second order kinetic model and Weber-Morris intraparticle diffusion model were used for kinetic analysis of NPX adsorption. The pseudo second order model was the best fitted kinetic model for NPX adsorption. The rate-controlling step was determined as the intraparticle diffusion step. The NPX adsorption on Amberlite resins was exothermic process. According to isotherm parameters, separation factor (R-L) values, kinetic and thermodynamic data, XAD-4 was found to be the most suitable adsorbent for NPX adsorption. Amberlite XAD-4 reached the maximum removal percentage (99.88%) at 0.5 g of adsorbent. NPX adsorption capacity of XAD-4 was 6.52 mg/g at 308 K, according to Langmuir isotherm model. (C) 2017 Elsevier B.V. All rights reserved.
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    Investigation of extractive interaction between ionic liquids and carbamazepine
    (Elsevier Science Bv, 2018) Sahin, Selin; Elhussein, Elaf Abdelillah Ali; Bilgin, Mehmet; Kurtulbas, Ebru; Bayazit, Sahika Sena
    Investigation of carbamazepine (CBP) extraction by four solvent systems containing ionic liquids (1-Butyl-3-methylimidazolium tetrafluoroborate-IL-1 and 1-Butyl-3-methyl-imidazolium hexafluoro phosphate-IL-2) as extractant in four diluents (diethyl adipate-DEA, diethyl malonate-DEM, diethyl succinate-DES and dibutyl phthalate-DBP) was performed at ambient temperature. The results were evaluated in terms of extraction yield (%) and distribution coefficient. IL-2 + DEA extractant system had the highest yield of CBP recovery with 88.45%. Regarding IL-1, the best performance was achieved by DEM with 82.03% of CBP recovery. Neutral media with the lowest addition of ionic liquid (20%, v/v) was found to be the optimum conditions to obtain the maximum recovery. (C) 2018 Elsevier B.V. All rights reserved.
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    Preparation of chromium fumarate metal-organic frameworks for removal of pharmaceutical compounds from water
    (Korean Institute Chemical Engineers, 2022) Kurtulbas, Ebru; Sahin, Selin; Bilgin, Mehmet; Bayazit, Sahika Sena
    Pharmaceutical pollution in water is the major cause of antibiotic resistance, so remediation of water from pharmaceuticals is a very important issue. Different methods are used for this purpose, with adsorption as one of the most preferred. Different adsorbents have been used for water treatment processes. Metal-organic frameworks that have highly porous structures have gained attention in the last decades. In this study, novel chromium fumarate (Cr-Fum) was prepared, and the efficiency of Cr-Fum was tested by ciprofloxacin (CPX) adsorption. Cr-Fum was prepared under reflux and characterized by scanning electron microscopy (SEM), X-ray diffraction spectroscopy (XRD), Fourier transform infrared spectroscopy (FTIR), thermal analysis (TGA), and differential scanning calorimetry (DSC). The general approach of the process was monolayer adsorption at low temperature and heterogeneous adsorption at high temperature. 2.5 mg of adsorbent was adsorbed 4.97 mg/g and 11.47% of CPX. 10 mg of Cr-Fum was adsorbed 0.82 mg/g and 7.27% of CPX. Partition coefficients were calculated and 0.07 mg/g/mu M was found at 298 K. The reaction followed pseudo-first- and pseudo-second-order kinetic models. Thermodynamic analysis showed that the reaction is spontaneous and exothermic. Additional ions caused decreasing CPX adsorption, but this study showed that Cr-Fum has NaCl adsorption capacity. In future studies, NaCl adsorption should be investigated. Desorption studies were applied to Cr-Fum after the adsorption processes. 0.1 M NaOH and phosphate buffer (pH=7.4) solution were used as desorption eluents. The desorption period was chosen as 6 h. NaOH solution desorbed 67.38% of CPX at first cycle and buffer solution desorbed 26.87% of CPX at second cycle.