Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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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 Pvc/Pan-immobilized H2TiO3 Adsorbent: a Tailored Titanium-Based Lithium-Ion Sieve for High-Performance Lithium Recovery(Royal Soc Chemistry, 2025) Recepoglu, Yasar Kemal; Ipek, Onur; Yuksel, AsliThe increasing demand for lithium, driven by the rapid development of electric vehicles and energy storage systems, has created a pressing need for efficient and sustainable lithium recovery technologies. Conventional methods often face challenges related to selectivity, environmental impact, and scalability, necessitating the development of alternative materials. In this study, a polyvinyl chloride/polyacrylonitrile (PVC/PAN)-immobilized titanium-based lithium-ion sieve (HTO) was synthesized for lithium recovery from aqueous media, including geothermal brine. The objective was to obtain a selective, reusable, and mechanically stable adsorbent suitable for industrial-scale applications. The synthesized PVC/PAN-HTO composite was characterized by FT-IR, BET, XRD, and SEM techniques. Batch adsorption studies showed that the optimum lithium recovery occurred at pH 12, with efficiencies of 98.7% in model lithium solutions and 91.6% in geothermal water using a 4 g L-1 adsorbent dosage. Adsorption kinetics followed a pseudo-second-order model, and the Langmuir isotherm provided the best fit, indicating monolayer adsorption with a maximum capacity of 5.79 mg g-1. Thermodynamic analysis confirmed that the adsorption process is spontaneous and exothermic. Reusability tests demonstrated stable performance over three adsorption-desorption cycles, confirming the potential of PVC/PAN-HTO for practical lithium extraction applications.Article Advanced Adsorptive Removal of Dimethyl Phthalate From Water Using a Tertiary Amine-Functionalized Polymeric Resin: Insights Into Experimental Design and Statistical Analysis(Royal Soc Chemistry, 2025) Turekkan, Kubranur; Recepoglu, Yasar Kemal; Ova Ozcan, Duygu; Arar, OzgurThis study investigates the effective removal of dimethyl phthalate (DMP) from aqueous solutions using Purolite Macronet MN100, a polymer-based adsorbent containing tertiary amine functional groups. A series of batch experiments was performed to assess the influence of resin dosage and solution pH, while adsorption kinetics were analyzed to determine the optimal contact time and the underlying rate-limiting mechanism. Equilibrium data were interpreted using adsorption isotherm models, and thermodynamic parameters (Delta G degrees, Delta H degrees, and Delta S degrees) were calculated to evaluate the feasibility and spontaneity of the process. Additionally, the effect of common coexisting ions in wastewater (Na+, K+, Mn2+, Ca2+, Mg2+) on DMP removal was examined. The optimum removal efficiency (>97%) was achieved using 0.02 g of resin per 25 mL solution at pH 2-6, with equilibrium established within 300 minutes. The adsorption behavior was best described by the Langmuir isotherm, indicating monolayer adsorption with a maximum capacity of 463.37 mg g(-1). Mechanistic evaluation revealed that pi-pi interactions and hydrogen bonding were the dominant forces driving DMP adsorption. The presence of competing cations had minimal impact, demonstrating the adsorbent's strong selectivity toward DMP. Desorption studies showed complete DMP recovery using absolute ethanol (>99%), with >99% regeneration efficiency. Optimization using Central Composite Design (CCD) under Response Surface Methodology (RSM) produced a statistically robust model (R-2 = 0.98), consistent with the experimental results. Overall, Purolite MN100 proved to be a highly efficient, selective, and regenerable adsorbent suitable for DMP removal in wastewater treatment processes.Article Citation - WoS: 4Citation - Scopus: 4Sulfonated Cellulose: a Strategy for Effective Methylene Blue Sequestration(Amer Chemical Soc, 2025) Toy, Mustafa; Recepoglu, Yasar Kemal; Arar, OzgurThis study investigates the sulfonation modification of cellulose for the removal of methylene blue (MB) from aqueous solutions. The prepared biosorbent was characterized, and its sorption capacity, kinetics, and thermodynamics were systematically evaluated. Fourier-transform infrared (FTIR) spectroscopy analyzed structural modifications, while scanning electron microscopy (SEM) examined the surface properties. The optimal sorbent dosage was determined as 0.05 g. MB removal efficiency increased from 11% at pH 1 to 70% at pH 2, reaching 99% within the pH range of 3 to 7. Kinetic studies revealed rapid sorption, achieving 99% removal within 3 min. Among various isotherm models, the Langmuir model provided the best fit (R 2 = 0.9989), indicating monolayer sorption with a maximum capacity of 37.65 mg/g. Thermodynamic analysis showed negative Delta G degrees values, confirming a spontaneous sorption process, while an enthalpy change (Delta H degrees) of -33.5 kJ/mol indicated exothermic behavior. The entropy change (Delta S degrees) of -82.6 J mol-1<middle dot>K-1 suggested decreased disorder during sorption. Regeneration studies demonstrated that 0.2 M HCl combined with ethanol achieved the highest desorption efficiency, and after three cycles, the MB removal efficiency remained above 99%. The presence of -SO3 - groups played a crucial role in MB sorption via ion exchange and may also contribute through hydrogen bonding, thereby enhancing MB sorption. These findings highlight sulfonated cellulose as an efficient and regenerable biosorbent for MB removal, offering valuable insights into its sorption mechanisms.