Scopus İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/395
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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: 3Citation - Scopus: 4Optimization of Carbon Dioxide Absorption in a Continuous Bubble Column Reactor Using Response Surface Methodology(Wiley, 2023-05-28) Gul, Ayse; Derakhshandeh, Masoud; Un, Umran TezcanCarbon dioxide absorption using amine based solvents is a well-known approach for carbon dioxide removal. Especially with the increasing concerns about greenhouse gas emissions, there is a need for an optimization approach capable of multifactor calibration and prediction of interactions. Since conventional methods based on empirical relations are not efficiently applicable, this study investigates use of Response Surface Methodology as a strong optimization tool. A bubble column reactor was used and the effect of solvent concentration (10.0, 20.0 and 30.0 vol%), flow rate (4.0, 5.0 and 6.0 L min-1), diffuser pore size (0.5, 1.0 and 1.5 mm) and temperature (20.0, 25.0 and 30.0 degrees C) on the absorption capacity and also overall mass transfer coefficient was evaluated. The optimization results for maintaining maximum capacity and overall mass transfer coefficient revealed that different optimization targets led to different tuned operational factors. Overall mass transfer coefficient decreased to 34.7 min-1 when the maximum capacity was the desired target. High reaction rate along with the highest absorption capacity was set as desirable two factor target in this application. As a result, a third scenario was designed to maximize both mass transfer coefficient and absorption capacity simultaneously. The optimized condition was achieved when a gas flow rate of 5.9 L min-1, MEA solution of 29.6 vol%, diffuser pore size of 0.5 mm and temperature of 20.6 degrees C was adjusted. At this condition, mass transfer coefficient reached a maximum of 38.4 min-1, with a forecasted achievable absorption capacity of 120.5 g CO2 per kg MEA.Article Citation - WoS: 5Citation - Scopus: 6Enhancing 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 - WoS: 10Citation - Scopus: 13Carbon Dioxide Absorption Using Monoethanolamine, Piperazine and N-Metil Solvents Under Counter Current Regime in Packed Column Reactor(Elsevier Sci Ltd, 2024-01) Gul, Ayse; Baris, Mesut; Un, Umran TezcanIn this research the carbon dioxide absorption using Monoethanolamine (MEA), Piperazine (PZ) and N-Metil-2-pirolidon (NMP) solvents and their different blends (MEA/NMP, PZ/NMP, MEA/PZ) in packed column reactor filled with Raschig rings was investigated and compared for efficient carbon dioxide absorption. The process was followed in a countercurrent regime under a liquid flow rate of 200 mL/min, gas flow rate of 2.5 L/min, and CO2 concentration of 50,000 ppm. Carbon dioxide removal efficiency (%), absorption capacity (mol CO2/mol solvent), overall mass transfer coefficient (1/min) and absorption rate (mol/l.s) were monitored. The highest obtained values for carbon dioxide removal efficiency, absorption capacity and overall mass transfer coefficient were 57.5%, 0.148 mol CO2/mol solvent and 2.178 min-1 respectivelly when 0.03 M MEA/0.07 M PZ in a hybrid system was used. It was concluded that PZ blends with MEA were successful absorbent as the organic physical solvent whereas NMP didn't show improving effect in blends with MEA on the absorption efficiency.