Browsing by Author "Özgüven, A."

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An Investigation Based on Removal of Ibuprofen and Its Transformation Products by a Batch Activated Sludge Process: a Kinetic Study
(Yildiz Technical University, 2021) Özgüven, A.; Öztürk, D.; Bayram, T.
Ibuprofen metabolites can form in humans as a result of metabolic activities or can be produced by microorganisms in wastewater treatment plants and receiving environments, which increases their likelihood of being present in the environment. In this study, various experiments were conducted to determine the removal degree for ibuprofen, ibuprofen carboxylic acid (IBU-CBX), and 2-hydroxylated ibuprofen (IBU-2-OH) metabolites with an activated sludge reactor. Furthermore, the pseudo-first-order biodegradation rate constant (kbiol) (17.76 L/gSSday) was calculated to determine the decomposition degree of ibuprofen in the batch activated sludge system. The effects of different ibuprofen concentrations (8.2, 5.6, 3.2, 1.51 mg/L) at constant biomass concentration (3 g/L) on the biodegradation mechanism were investigated. In addition, IBU-2-OH and IBU-CBX were tested in a batch activated sludge reactor with a volume of 2 L individually at 100 μg/L with activated sludge containing 3 g/L biomass. It was observed that ibuprofen had a removal efficiency of more than 90%. IBU-CBX and IBU-2-OH were removed at approximately 27–91% and 18–82%, respectively. In abiotic conditions, the removal of ibuprofen was found to be 7.07%. It was confirmed that the removal of ibuprofen largely depended on biological degradation. This study enabled us to know which metabolites are involved in the biodegradation process of ibuprofen in batch experiments with the activated sludge process. Copyright 2021, Yıldız Technical University.
The Utilization of a Statistical Program for Chemical Oxygen Demand Reduction and Diclofenac Sodium Removal From Aqueous Solutions Via Agaricus Campestris/Amberlite Styrene Divinylbenzene Biocomposite
(Springer Science and Business Media Deutschland GmbH, 2022) Özgüven, A.; Yönten, V.; Kıvanç, M.R.
In our study, medium conditions were optimized for percent chemical oxygen demand (COD) reduction and drug removal from diclofenac sodium (DFS) solutions. Response surface methodology/central composite design was used for optimization. A. Campestris/Amberlite Styrene–divinylbenzene (XAD-4) biocomposite material was used as adsorbent. Four independent parameters (pH, initial concentration, interaction time and adsorbent amount) were chosen to optimize both % COD reduction and DFS removal. As a result of experiments, maximum 77% COD reduction and maximum 98% DFS removal were obtained at 4 pH, 225 mg/L initial concentration, 36 min and 0.69 adsorbent amount. Scanning electron microscope and Fourier transform infrared spectroscopy devices were used for characterization of adsorbent material. To identify the isotherm for the adsorption mechanism, the Langmuir, Freundlich, Temkin and Harkins–Jura isotherm equations were examined. The Freundlich isotherm had 96.2% regression coefficient (R2) and was linear, so had better fit compared to the other equations and the adsorption mechanism abided by the Freundlich isotherm. The results show that statistical optimization design was successfully applied to experiments and A. Campestris/Amberlite XAD-4 is an appropriate biocomposite adsorbent with specific affinity for % COD reduction and removal of DFS from aqueous solutions under optimal conditions. © 2021, King Fahd University of Petroleum & Minerals.