Browsing by Author "Hanay, Ozge"

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Adsorption of Chlortetracycline From Aqueous Solution by Chitin
(Taylor & Francis inc, 2020) Tunc, Muskun Sara; Hanay, Ozge; Yildiz, Burcin
In this study, the performance of chitin for removing chlortetracycline (CTC) from aqueous solutions was assessed. The effects of pH, chitin dose, CTC concentration and contact time on CTC adsorption by chitin were investigated. The maximum CTC removal efficiency of 82.9% was determined at pH 7, chitin dose of 5 g/L, CTC concentration of 8.8 mg/L and contact time of 120 min. The highest CTC adsorption capacity was found as 12.01 mg/g for CTC of 82.2 mg/L concentration at pH 7. The results demonstrated that CTC removal efficiency decreased from 82.9% to 73.0% with increasing CTC concentration from 8.8 to 82.2 mg/L. The equilibrium data for CTC adsorption indicated a good fit to the Freundlich isotherm model. Pseudo-second-order kinetic model was the best model for describing the adsorption reactions.
In-Situ Generation of H2o2 in Heterogeneous Fenton-Like Process With Fe/Ni Bimetallic Particle for Metronidazole Degradation
(Taylor & Francis inc, 2022) Yildiz, Burcin; Yucel, Ahmet; Hanay, Ozge
A microscale Fe/Ni bimetallic particle was examined to convert O-2 to H2O2 and further to center dot OH radicals and to degrade metronidazole (MNZ) antibiotic in a heterogeneous Fenton-like reaction. The properties of the bimetallic particle before and after the reaction were studied using SEM, EDX, XRD, and BET techniques. The complete removal of MNZ was achieved within 15 min with an initial pH of 3, oxygen flow rate of 150 L/h, Fe/Ni of 1 g/L, and MNZ of 25 mg/L. Under these conditions, the maximum H2O2 concentration of about 31 mg/L was generated but only 27% of TOC was removed after 60 min. The presence of NaCl and the high ionic strength accelerated the iron dissolution and MNZ removal efficiency. The reaction was mainly inhibited at the solution pH of 7, implying the significance of solution pH in Fenton-like process. Besides, the possible MNZ degradation pathway was further proposed based on the intermediates identified by GC/MS. Acetamide was monitored as the degradation intermediate. The results showed a significant contribution on the usage of a catalyst for in-situ generation of H2O2 via the activation of dissolved oxygen.