Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
Browse
2 results
Search Results
Article Quaternary Ammonium Functionalized Cellulose for Bromate Ion Removal: Structural Insights and Efficacy Evaluation(Wiley, 2025) Koseoglu, Ecem; Senver, Buse Aleyna; Recepoglu, Yasar Kemal; Arar, OzgurThis study evaluates the potential of quaternary ammonium-modified cellulose as a biosorbent for bromate (BrO3-) removal from aqueous solutions. Elemental analysis and scanning electron microscopy (SEM) characterized the elemental composition and microstructural features of the biosorbent, whereas Fourier-transform infrared (FTIR) spectroscopy elucidated its molecular structure. Experimental results revealed that BrO3- removal efficiency increased with the biosorbent dose, achieving approximately 58%, 78%, and 90% removal with 0.025, 0.05, and 0.2 g of sorbent, respectively. The removal was pH-dependent, with efficiencies of 25%, 45%, and 76% at pH 2, 4, and 10, respectively, and the optimal removal was within the pH range of 6-8. Kinetic studies demonstrated rapid sorption, achieving 91% removal within 3 min. The Langmuir sorption isotherm model provided an excellent fit to the experimental data (R 2 = 0.9987), indicating a maximum sorption capacity of 9.40 mg/g. Thermodynamic analyses confirmed a spontaneous and endothermic sorption process (triangle G degrees = -8.11 kJ/mol; triangle H degrees = +2.22 kJ/mol). Desorption studies showed >= 99.9% efficiency using 0.1-M H2SO4 and NaCl, with NaCl selected as the preferred regenerant to minimize acid consumption. The biosorbent retained over 90% removal efficiency across three regeneration cycles. These findings highlight the potential of quaternary ammonium-modified cellulose as a sustainable and efficient material for BrO3- removal from water systems.Article Citation - WoS: 4Citation - Scopus: 5Breakthrough Curve Analysis of Phosphorylated Hazelnut Shell Waste in Column Operation for Continuous Harvesting of Lithium From Water(Elsevier, 2024) Recepoğlu, Yaşar Kemal; Arar, Ozguer; Yuksel, AsliIn batch-scale operations, biosorption employing phosphorylated hazelnut shell waste (FHS) revealed excellent lithium removal and recovery efficiency. Scaling up and implementing packed bed column systems necessitates further design and performance optimization. Lithium biosorption via FHS was investigated utilizing a continuous-flow packed-bed column operated under various flow rates and bed heights to remove Li to ultra-low levels and recover it. The Li biosorption capacity of the FHS column was unaffected by the bed height, however, when the flow rate was increased, the capacity of the FHS column decreased. The breakthrough time, exhaustion time, and uptake capacity of the column bed increased with increasing column bed height, whereas they decreased with increasing influent flow rate. At flow rates of 0.25, 0.5, and 1.0 mL/min, bed volumes (BVs, mL solution/mL biosorbent) at the breakthrough point were found to be 477, 369, and 347, respectively, with the required BVs for total saturation point of 941, 911, and 829, while the total capacity was calculated as 22.29, 20.07, and 17.69 mg Li/g sorbent. In the 1.0, 1.5, and 2.0 cm height columns filled with FHS, the breakthrough times were 282, 366, and 433 min, respectively, whereas the periods required for saturation were 781, 897, and 1033 min. The three conventional breakthrough models of the Thomas, Yoon-Nelson, and Modified Dose-Response (MDR) were used to properly estimate the whole breakthrough behavior of the FHS column and the characteristic model parameters. Li's extremely favorable separation utilizing FHS was evidenced by the steep S-shape of the breakthrough curves for both parameters flow rate and bed height. The reusability of FHS was demonstrated by operating the packed bed column in multi-cycle mode, with no appreciable loss in column performance.