Scopus İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/395
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Article Optimizing Nanoclay-Enhanced Membranes for Oil Rejection Using Response Surface Methodology(Wiley, 2026) Gul, Ayse; Baris, Mesut; Boyraz, Pınar; Senol-Arslan, Dilek; Alibaz, Name NurThe efficient separation of waste oil from contaminated water is critical due to its challenges in environmental and industrial applications. This study investigated the production and optimization of polysulphone (PSF) membranes using two different types of clay (nanomer clay/CN and commercial nanoclay/NC). Response Surface Methodology (RSM) was applied to optimize the basic production parameters and nanoclay concentrations systematically to maximize oil rejection and permeability flow. The experimental results showed that NC and CN significantly increased the hydrophilicity, permeability, and fouling resistance of the membrane compared to pure PSF membranes. The contact angle significantly decreased from 64.34 degrees (pristine PSF) to 36.23 degrees (2% NC), indicating highly improved hydrophilicity. Consequently, the pure water flux increased from 177.2 L/m2 h to a maximum of 248.6 L/m2 h (1% NC). Furthermore, the modified membranes exhibited outstanding anti-fouling properties; the flux recovery ratio (FRR) improved from 88.09% to 96.20% (1% CN), while the decline ratio (DR) drastically dropped from 60.89% to 32.14%. The optimized condition for maximum removal efficiency using a modified quadratic model revealed that 2572 mg/L oil can be treated with a PSF membrane containing 2.0% CN to remove 98.271% of the oil. The model also suggests superiority of CN over NC with desirability factors of 0.978 and 0.900, respectively, while both demonstrated high efficiency. This theoretically modeled experimental comparative study highlights the importance of PSF membrane technology for efficient and sustainable oil-water separation and demonstrates the promising potential of nanoclay modifications.Article Citation - WoS: 6Citation - Scopus: 6The Different Impacts of g-C3N4 Nanosheets on PVDF and PSF Ultrafiltration Membranes for Remazol Black 5 Dye Rejection(Wiley, 2023-08-02) Senol-Arslan, Dilek; Gul, Ayse; Dizge, Nadir; Ocakoglu, Kasim; Uzal, NigmetMembranes combined with nanoparticles are an excellent combination capable of successfully removing various contaminants, such as dyes from wastewater while using very little energy and decreasing pollution. The present study reports an efficient approach for Remazol Black 5 (RB5) dye removal using composite graphitic carbon nitride nanosheets (g-C3N4), polysulfone (PSF), and polyvinylidene fluoride (PVDF) membranes. The membranes were prepared using the phase inversion method, with varying quantities of g-C3N4 nanosheets ranging from 0.1%, 0.2% to 0.3%. The prepared g-C3N4 nanosheets were characterized by FTIR, SEM analyses, and zeta potential measurements. FTIR and SEM studies, contact angle, water permeability, COD, and dye rejection measurements were used to characterize the g-C3N4 nanosheets embedded in PSF and PVDF membranes. After the addition of 0.3 wt% g-C3N4, the water flux of the 0.3 wt% g-C3N4 embedded PSF membrane was the highest, whereas the water flux of the 0.3 wt% g-C3N4 embedded PVDF membrane was the lowest. The ultrafiltration (UF) membrane's performance with g-C3N4 embedded showed an RB5 rejection rate of more than 80% and a COD removal efficiency of more than 45%. The results of the experimental filtration showed that RB5 rejection reached maximum values of 91.3% for 0.1 wt% g-C3N4/PSF, and 85.6% for 0.3 wt% g-C3N4/PVDF.Article Citation - WoS: 14Citation - Scopus: 14Isotherms, Kinetics and Thermodynamics of Pb(II) Adsorption by Crosslinked Chitosan/Sepiolite Composite(Springer, 2021-04-13) Senol-Arslan, DilekA novel composite adsorbent was prepared from chitosan (Ch) and sepiolite (S) for removal of Pb(II) from aqueous solution. The Ch-S composite beads were successfully synthesized by crosslinking epichlorohydrin (ECH) and tripolyphosphate (NaTPP). A number of physicochemical parameters such as, pH, initial Pb(II) concentration, temperature, contact time and desorption have been studied during the adsorption process. Experimental data acquired from batch adsorption tests have been analyzed by three isotherm models (Langmuir, Freundlich and Dubinin-Radushkevich), and three kinetic models including the pseudo-first-order, the pseudo-second-order and intraparticle diffusion equations using nonlinear regression technique. Langmuir isotherm was the best to fit the experimental data (R-2 = 0.971). The maximum adsorption capacity was 0.158 mol kg(-1) from Langmuir isotherm model. Maximum removal efficiency was found approximately 66% for the initial Pb(II) concentration of 1000 mg/L, adsorbent dosage of 100 mg and agitation speed of 150 rpm at pH 4.5. The adsorption free energy was found as E-DR (15.8 kJ mol(-1)), which indicated that Pb(II) adsorption process onto Ch-S composite was chemically performed. The kinetic studies have shown that the best fitted kinetic model is the pseudo-first order (R-2 = 0.979). Adsorption enthalpy value was determined as 18.7 kJ mol(-1), adsorption entropy was found as 106 J mol(-1) K-1, and Gibbs free energy was found as 12.9 kJ mol(-1). The thermodynamic parameters showed that the adsorption of Pb(II) on Ch-S was endothermic, possible and spontaneous.Article Citation - WoS: 11Citation - Scopus: 13Fabrication and Characterization of Silane-Functionalized Na-Bentonite Polysulfone/Polyethylenimine Nanocomposite Membranes for Dye Removal(Wiley, 2020-02-04) Saki, Seda; Senol-Arslan, Dilek; Uzal, NigmetIn this study, tetraethoxysilane (TEOS)-functionalized Na-bentonite incorporated into polysulfone/polyethylenimine (PSF/PEI) membranes were fabricated by phase inversion method for the efficient removal of methylene blue dye. For the preparation of PSF/PEI nanocomposite membranes, silane-functionalized Na-bentonite and pure Na-bentonite were used at three different concentrations (0.5, 1, and 2 wt%). The prepared membranes were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, atomic force microscopy, porosity, hydrophilicity, and water permeability measurements. Antifouling behaviors and methylene blue dye rejections of the PSF/PEI nanocomposite membranes were also tested. The obtained results showed that the addition of pure Na-bentonite and silane-functionalized Na-bentonite both increased the water permeability of the membranes. The PSF/PEI membrane containing 2 wt% silane-functionalized Na-bentonite showed the highest water flux of 105 L m(-2) h(-1), while the lowest water flux of 1.2 L m(-2) h(-1) was recorded for pure PSF membrane. Filtration results demonstrated that the antifouling capacity was significantly increased due to the negatively charged surface of the newly generated silane-functionalized Na-bentonite PSF/PEI membranes. In summary, TEOS-functionalized Na-bentonite can be used to fabricate PSF/PEI nanocomposite membranes with effective filtration ability, antifouling capacity with lower decay ratio, higher flux recovery ratio, and 99% methylene blue dye removal performance.Article Citation - WoS: 4Citation - Scopus: 4Enhancing Oil Rejection in PVDL and PSF Membranes: The Role of SiO2 NPS(Wiley, 2024-12-17) Senol-Arslan, Dilek; Gul, AyseOily water negatively affects both land and marine ecosystems. To combat this, membrane production can effectively treat oil waste and recycle over 90% of it. This study compares the influence of SiO2 nanoparticles on oil rejection in two types of membranes: polyvinylidene fluoride (PVDF) and polysulfone (PSF). The SiO2 NPs are characterized by FTIR, SEM analysis, and zeta potential measurements. SiO2 NPs embedded PSF and PVDF membranes were characterized by FTIR, SEM analysis, contact angle, water permeability, oil rejection measurements, and recycling experiments. The results of the experiments showed that oil rejection reached maximum values of 92.2% for 2 wt% PSF/SiO2, and 94.1% for 2 wt% PVDF/SiO2 membranes. The experimental results demonstrate that the incorporation of SiO2 nanoparticles enhances the oil rejection efficiency of two distinct membrane types, exhibiting notable performance disparities contingent on the selected membrane material. This methodology achieves a recycling rate of over 90% for oil waste, signifying a substantial advancement in environmental protection and sustainable development. Consequently, the membrane production technique is regarded as an efficacious approach for the management and recycling of oil waste.Article Citation - Scopus: 1Eco-Friendly Fabrication of Cellulose-Derived Polyvinylidene Fluoride Membranes From Wastepaper for Efficient Fe(II) Removal From Mine Wastewater(Wiley, 2025-08-15) Gul, Ayse; Senol-Arslan, DilekThis study investigates the feasibility of utilizing cellulose membranes derived from wastepaper to remove Fe(II) ions from mine wastewater. In this context, the recycled material cellulose was employed in the membrane synthesis process to produce an environmentally friendly membrane that efficiently removes Fe(II) ions. Furthermore, the study proposes a cost-effective and sustainable solution for removing heavy metals, with comprehensive analysis and experimentation on the potential application of cellulose membranes in the treatment of mine wastewater. The membranes were fabricated from polyvinylidene fluoride (C2H2F2)n (PVDF) and cellulose nanoparticles (CNs) produced from wastepaper by a common phase inversion method. Water filtration and Fe(II) rejection tests were operated on a batch scale. The fabricated CNs were characterized by Fourier transform infrared (FTIR) and SEM-energy-dispersive X-ray (EDX) analyses. Water permeability, contact angle, SEM-EDX analysis and FTIR were used to analyze PVDF/CN membranes. The water flux for PVDF and PVDF + CN membranes increased from 164.5 to 2241 L m-2 h-1 on the addition of CNs from 1% to 3%. The experimental results demonstrate the best cellulose membrane containing 11% PVDF + 2% CN effectively removed approximately 58% of Fe(II). The findings of this research emphasize the importance of environmentally friendly approaches in addressing clean water challenges and highlight the reuse potential of waste materials for innovative applications. Consequently, this study provides an alternative to the development of sustainable and cost-effective solutions for wastewater treatment in accordance with the principles of circular economy and environmental sustainability. (c) 2025 Society of Chemical Industry.Article Citation - WoS: 2Citation - Scopus: 2Diffuse-Layer Surface Potentials of Colemanites Mined in Turkey(Oficyna Wydawnicza Politechniki Wrocławskiej, 2022-07-07) Arslan, Dilek Senol; Drelich, Jaroslaw W.; Senol-Arslan, DilekColemanite crystal specimens were handpicked at Kestelek, Emet (Hisarcik, Espey), Bigadic mines in Turkey for characterization of their composition and surface potential. X-ray diffraction analysis revealed no differences in mineralogical makeup of the crystals, but elemental analysis indicated differences in the type of trace (<0.1 wt%) elements. Zeta potential measurements showed small differences in zeta potential values, with isoelectric points (iep) varying from about pH = 9.6 to pH = 10.2. However, no correlation was found between iep and the type of trace elements. Additionally, atomic force microscopy (AFM) was employed to measure the colloidal interactions between a silicon nitride (Si3N4) cantilever tip and colemanite crystal surfaces in 1 wt% colemanite-saturated aqueous solutions at three different pHs (8.4, 9.4 and 11). The Derjaguin-Landau-Verwey-Overbeek theory (DLVO) was applied to examine the AFM tip interactions with colemanite surfaces in an aqueous solution of colemanite saturated solutions. The results revealed attractive forces at pH = 8.4 and 9.4 and repulsive forces at pH = 11, confirming the location of an isoelectric point for colemanite specimens somewhere between pH = 9.5 and pH = 10.1. Theoretical analysis of the force curves using the DLVO theory allowed for assessment of both surface charge density and surface potential for colemanite specimens used in this study.Article Türkiye’de Farklı Yörelerde Bulunan Kolemanit Minerallerinin Fiziksel, Kimyasal Ve Termal Özelliklerinin Tayini(Gumushane University, 2021-08-24) Senol-Arslan, Dilek; Arslan, Dilek Senol; Şenol Arslan, DilekIn this study, colemanite is an important boron mineral which constitutes about 76% of Turkey's boron reserves, is frequently used in applications obtained as a result of scientific and technological developments. In this context, a detailed literature survey was carried out colemanite minerals. Characteristic and structural features of the colemanite samples of four different regions (Kestelek, Emet (Hisarcık, Espey), Bigadiç regions) were determined by analyzes such as X-Ray Diffraction (XRD), Inductively Coupled Plasma, ICP and Mass Spectrometry, MS (ICP-MS), Thermogravimetric and Differential thermal analysis (TG-DTA), and Fouier Transform Infrared Spectroscopy (FT-IR) methods. In line with these findings, the mineralogical, chemical and thermal properties of pure colemanite crystals were determined and the similarities and differences between the samples were revealed. © 2025 Elsevier B.V., All rights reserved.