Browsing by Author "Gul, Ayse"

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Carbon dioxide absorption using monoethanolamine, piperazine and n-metil-2-pirolidon solvents under counter current regime in packed column reactor
(ELSEVIER SCI LTD, 2024) Gul, Ayse; Barış, Mesut; Un, Umran Tezcan; 0000-0002-2305-6408; AGÜ, Mühendislik Fakültesi, İnşaat Mühendisliği Bölümü; Gul, Ayse
In 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.
The different impacts of g-C3N4 nanosheets on PVDF and PSF ultrafiltration membranes for Remazol black 5 dye rejection
(WILEY, 2023) Senol-Arslan, Dilek; Gul, Ayse; Dizge, Nadir; Ocakoglu, Kasim; Uzal, Nigmet; 0000-0001-9639-2843; 0000-0002-0912-3459; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Senol-Arslan, Dilek; Uzal, Nigmet
Membranes 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.
Enhancing Oil Rejection in PVDF and PSF membranes: The Role of SiO2 NPs
(WILEY, 2025) Senol-Arslan, Dilek; Gul, Ayse; 0000-0001-9639-2843; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Senol-Arslan, Dilek; Gul, Ayse
Oily 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.
Ni-Zn metal-organic framework based membranes for rejection of Pb (II) ions
(ELSEVIERRADARWEG 29, 1043 NX AMSTERDAM, NETHERLANDS, 2022) Senol-Arslan, Dilek; Gul, Ayse; Uzal, Nigmet; Yavuz, Emre; AGÜ, Mühendislik Fakültesi, Malzeme Bilimi ve Nanoteknoloji Mühendisliği Bölümü; Şenol Arslan, Dilek; Gül, Ayşe; Uzal, Niğmet
The present paper describes a sustainable and affordable supply of clean, and safe water approach to investigate Ni-Zn MOF embedded membrane for rejection of Pb (II) ions in aqueous solution. Ni-Zn MOF powder was prepared by solvo-thermal method, and then the Ni-Zn MOF embedded membranes with various concentrations (0.025 wt%, 0.05 wt% and 0.1 wt%). The membranes were fabricated by a common phase inversion method. Phase solutions of Pb(II) prepared with PVP at different concentrations in aqueous solutions. Water filtration and Pb (II) rejection tests were operated on a batch scale. The prepared Ni-Zn MOF powder characterized by FTIR, SEM-EDX analyses and zeta potential measurements. Ni-Zn MOF membranes were characterized by FTIR, SEMEDX analysis, contact angle, and water permeability measurements. The effects of important parameters on adsorption including concentration and pH were investigated. The obtained results indicated that the maximum rejection of Pb(II) was 98% for a feed solution containing 80 mg Pb/L at pH 8 and assistance with 2 % PVP for 0.05 wt% Ni-Zn MOF membrane. Additionally, it was detected that blend membranes revealed better Pb(II) rejection than pure PSF membrane.