Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - WoS: 9Citation - Scopus: 10Investigation of Reactive Extraction of Monocarboxylic Acids With Menthol-Based Hydrophobic Deep Eutectic Solvent by Response Surface Methodology(Taylor & Francis Inc, 2023) Yıldız, Esra; Lalikoğlu, Melisa; Aşçı, Yavuz Selim; Sırma Tarım, BurcuThe growing demand for producing organic acids by fermentative techniques has increased the significance of separating carboxylic acids from their fermentation broth with the reactive extraction process. Considering the environmental impacts, deep eutectic solvents can be considered as a potential green alternative for the replacement of volatile organic solvents commonly used in the extraction process. In this study, a new type of green solvent named hydrophobic deep eutectic solvent (HDES) based on decanoic acid as a hydrogen bond acceptor and menthol as a hydrogen bond donor was utilized for the reactive extraction of formic, acetic, and propionic acids from their aqueous solutions. The effect of initial acid concentration, HDES molar ratio, and tri-n-octyl amine (TOA) concentration on extraction efficiency was investigated. Modeling of the reactive extraction process was performed via a response surface methodology with a central composite design. Herein, the effect of the parameters of TOA concentration, HDES molar ratio, and initial acid concentration on the distribution coefficient was investigated. According to the results, it was reported that the most effective parameter on the extraction efficiency (%E) was the amount of extractant. The results of the experimental studies showed that the highest separation efficiency was obtained for 5% initial concentrations of formic, acetic, and propionic acids by using a mixture of 0.5 HDES molar ratio solvent and 1.9 mol/L TOA. The extraction efficiencies of these acids were found to be 88.71, 92.52, and 95.90 with +/- 0.1 standard deviation, respectively.Article Citation - WoS: 11Citation - Scopus: 12Treatment of Sugar Industry Wastewater by Using Subcritical Water as a Reaction Media(Wiley, 2023) Orak, Ceren; Öcal, Bulutcem; Yüksel, AslıThe sugar industry is one of the most wastewater-producing industries and it contains high content of organic and inorganic substances. Treating and reusing wastewater has significant importance because sugar industry needs to use a high volume of water. In this study, sugar industry wastewater was treated under subcritical conditions and the impacts of reaction temperature and duration over TOC removal percentage were investigated. Additionally, the impact of NaOH concentration over TOC removal percentage was examined. The highest TOC removal was obtained almost 95 % in the presence of 0.1 M of NaOH at 240 degrees C for 90 min of reaction duration. Treatment of sugar industry wastewater by subcritical water oxidation followed the second-order reaction kinetic model and the activation energy was found as 11.41 kJ/mol. Furthermore, the intermediate products were identified via GC-MS.Article Citation - WoS: 3Citation - Scopus: 4Photocatalytic Degradation of Aquatic Organic Pollutants With Zn- and Zr-Based Metalorganic Frameworks: Zif-8 and Uio-66(TÜBİTAK - Türkiye Bilimsel ve Teknolojik Araştırma Kurumu, 2022) Çalık, Fatma Defne; Erdoğan, Bilgesu; Yılmaz, Esra; Saygı, Gizem; Çakıcıoğlu-Özkan, FehimeWater treatment has been an essential issue with the increasing population over 40 years. Researchers center on the major organic pollutants, such as dyes, pesticides, and pharmaceutical products. Photocatalytic degradation is one of the promising methods for aquatic organic pollutant treatment. Over the years, scientists have been working on developments for photocatalysts to enhance their pollutant degradation performances. From the reviewed studies, it is seen that properties like surface area, chemical, mechanical, and thermal stability, and uniform distribution of active sites are crucial, and an increase in these properties provides better degradation efficiency. In this sense, metal-organic frameworks as photocatalysts can be considered more advantageous. This study focuses on the organic aquatic pollutant degradation studies by using well-known MOFs like ZIF-8 and UiO-66 photocatalysts. Mainly the organic dye (RhB, MB, MO, etc.) degradation efficiencies of ZIF-8 and UiO-66 have been achieved to 100%. Recently, the degradation capacities of various pharmaceuticals such as diazinon, acetaminophen, levofloxacin, and sulfamethoxazole have also been investigated. According to the reviewed studies, ZIF-8 and UiO-66 can be considered remarkable photocatalysts for the degradation of organic pollutants.Article Citation - WoS: 3Citation - Scopus: 3Numerical Study of Electrostatic Desalting: a Detailed Parametric Study(MDPI, 2022) Ramirez-Argaez, Marco A.; Abreú-López, Diego; Gracia-Fadrique, Jesús; Dutta, AbhishekA systematic process analysis was conducted to study the effect of the main variables in an industrial electrostatic desalter, such as electric field intensity, wash water content, droplet size, and oil viscosity, on the efficiency of the separation of water from oil. The analysis was assessed through an already published and validated CFD multiphase numerical model that considers the expression of the frequency of collisions as a function of the mentioned process variables. Additionally, the study allowed the formal optimization exercise of the operation to maximize the separation efficiency. The most significant variables were the initial water content and the electric field intensity, while the temperature (oil viscosity) had an effect to a lower extent. An increase in the electric field and temperature and a decrease in the water content improved the water separation from oil. Optimum values suggested from the factorial experimental design and the optimization implemented in this work indicated the use of an electric field of 3 kV/cm, water content of 3%, and an oil viscosity of 0.017 kg/ms. At the same time, the droplet size showed no significant effect under the conditions explored in this work.Article Citation - WoS: 3Citation - Scopus: 4Microfluidic-Assisted Preparation of Nano and Microscale Chitosan Based 3d Composite Materials: Comparison With Conventional Methods(Wiley, 2022) Kimna, Ceren; Değer, Sibel; Tamburacı, Sedef; Tıhmınlıoğlu, FundaAlthough nanofillers contribute to improved physical characteristics and biological functionalities of polymer-based biomaterials, their dispersion in polymer matrices is still a challenging issue in terms of obtaining consistency for the inherent properties. To tackle this problem, homogenization techniques are applied to disperse the nanofillers in such polymers, however, these methods can cause undesired changes especially in the rheological properties and the physical structure of the biopolymer matrices. Recently, as a novel homogenization technique, microfluidization has been used to homogenize polymer nanocomposites to minimize these limitations. In this study, two different nanocomposite structures as chitosan/montmorillonite (CS/MMT) and chitosan/polyhedral oligomeric silsesquioxane nanocages (CS/POSS) were homogenized with microfluidization and investigated in terms of physical alterations. Furthermore, the effect of microfluidizer technique on material characteristics was compared with conventional homogenization techniques, i.e., ultrasonic bath and sonication in terms of solution, nano – (e.g., hydrodynamic size, drug encapsulation) and macroscopic material characteristics (e.g., porosity, mechanical properties, swelling and thermal degradation). It was found that the microfluidizer homogenization improves the physical characteristics in both nano and macroscale materials: Nanospheres obtained from CS/MMT composites showed enhanced stability, uniform size distribution (<100 nm, PDI: [removed]50%) whereas 3D porous CS/POSS scaffolds showed improved structural uniformity (i.e., homogeneous and interconnected microstructure) and enhanced thermal and mechanical properties. The obtained results indicate that the microfluidizer homogenization ensures a successful nanofiller dispersion in polymer matrices, thereby improving the biomaterial characteristics impressively compared to the sonication methods.Article Citation - WoS: 4Citation - Scopus: 5Co2 Absorption Into Primary and Secondary Amine Aqueous Solutions With and Without Copper Ions in a Bubble Column(TÜBİTAK - Türkiye Bilimsel ve Teknolojik Araştırma Kurumu, 2022) Yousefzadeh, Hamed; Güler, Cansu; Erkey, Can; Uzunlar, ErdalChemical absorption of CO2 into aqueous amine solutions using a nonstirred bubble column was experimentally investigated. The performance of CO2 absorption of four different primary and secondary amines including monoethanolamine (MEA), piperazine (PZ), 2-piperidineethanol (2PE), and homopiperazine (HPZ) were compared. The effects of initial concentration of amine, the inlet mole fraction of CO2, and solution temperature on the rate of CO2 absorption and CO2 loading (mol CO2/mol amine) were studied in the range of 0.02–1 M, 0.10–0.15, and 25–40 °C, respectively. The effect of the presence of copper ions in the amine solution on CO2 loading was also studied. By comparison of the breakthrough curves of the amines at different operational conditions, it was revealed that the shortest and longest time for the appearance of the breakthrough point was observed for MEA and HPZ solutions, respectively. CO2 loading of MEA, 2PE, PZ, and HPZ aqueous solutions at 25 °C, 0.2 M of initial concentration of amine, and 0.15 of inlet mole fraction of CO2 were 1.06, 1.14, 1.13, and 1.18 mol CO2/mol amine, respectively. By decreasing the inlet mole fraction of CO2 from 0.15 to 0.10, CO2 loading slightly decreased. As the initial concentration of amine and temperature decreased, CO2 loading increased. Also, the presence of copper ions in the absorbent solution resulted in a decrease in the CO2 loading of MEA and HPZ aqueous solutions. In case of PZ and 2PE amines, adding copper ions led to precipitation even at low copper ion concentrations.Article Citation - WoS: 13Citation - Scopus: 17Characterization and Beneficiation of Ethiopian Kaolin for Use in Fabrication of Ceramic Membrane(IOP Publishing, 2021) Zewdie, Tsegahun Mekonnen; Prihatiningtyas, Indah; Dutta, Abhishek; Habtu, Nigus Gabbiye; Van der Bruggen, BartKaolin (china clay) is a rock material that is very rich in kaolinite. A kaolin ore from Debre Tabor, Ethiopia containing 59.2 wt% SiO2, 24.9 wt% Al2O3, 2.4 wt% Fe2O3, and 8.22 wt% loss on ignition (LOI) was physically beneficiated, chemically leached, and thermally treated for possible industrial use, especially for ceramic membrane fabrication. The leaching experiments were carried out using oxalic acid solutions as leaching reagents for the iron extraction process. The effect of acid concentration, reaction temperature, and contact time on iron leaching was investigated. It was determined that the rate of iron extraction increased with the oxalic acid concentration, leaching temperature, and contact time. A substantial reduction of iron oxide (2.4 to 0.36 wt%) from the raw kaolin was observed at operating conditions of 2.0 M oxalic acid, the temperature of 120 degrees C, and contact time of 120 min. A maximum kaolin whiteness index of 81.4% was achieved through this leaching process. Finally, the physically beneficiated, chemically leached, and thermally treated kaolin raw material was used to fabricate a low-cost kaolin-based ceramic membrane. After firing at 1100 degrees C the ceramic membrane was found to have a mass loss of 11.04 +/- 0.05%, water absorption of 8.9 +/- 0.4%, linear shrinkage of 14.5 +/- 0.05%. It was demonstrated to be chemically stable, having less than 3% mass loss in acid solution, and less than 1% mass loss in alkali solution. The newly developed membranes have thus properties comparable to commercial ceramic membranes.Article Citation - WoS: 1Citation - Scopus: 1Selective Catalytic Hydrogenation of Cellulose Into Sorbitol With Ru-Based Catalysts(TÜBİTAK, 2022) Orak, Ceren; Sapmaz, Aycan; Yüksel, AslıSorbitol is one of the platform chemicals and can be produced from various renewable and sustainable sources via different processes. Hydrothermal liquefaction is an effective and promising approach to produce sorbitol, since the subcritical reaction media and appropriate catalysts provide a selective production of platform chemicals. In this study, sorbitol was produced from different renewable sources (cellulose and glucose) in the presence of Ru-based catalysts (Ru/SiO2, Ru/AC, Ru/SBA-15, and Ru/SBA-15-SO3) under subcritical conditions. The highest cellulose conversion was achieved as 90% in the presence of Ru/SBA-15-SO3 for 1 h of reaction duration. The highest sorbitol yield (%) by hydrothermal liquefaction of cellulose was obtained as 6.2% by using Ru/AC for 1 h of reaction duration. A total of 99.9% of glucose conversion was achieved in the presence of all catalysts. The highest sorbitol yield (%) by hydrothermal liquefaction of glucose was found as 3.8% for 1 h of reaction duration. Owing to the results of GC-MS analysis, the intermediate products were identified, and, thus, a reaction pathway was proposed.Article Citation - WoS: 5Citation - Scopus: 5Novel Biopolymer-Based Hydrogels Obtained Through Crosslinking of Keratose Proteins Using Tetrakis(hydroxymethyl) Phosphonium Chloride(Springer, 2022) Yalçın, Damla; Top, AybenMerino wool obtained from the Karacabey region of Turkey was solubilized using peracetic acid oxidation. The wool and extracted wool proteins (keratose) were characterized using SEM, XRD, TGA, and FTIR analyses. SDS-PAGE result of the keratose indicated diffusive bands were populated between ~ 40 and ~ 55 kDa, corresponding to low-sulfur content α-keratose proteins. Chemically crosslinked hydrogels were prepared using the keratose and tetrakis(hydroxymethyl) phosphonium chloride (THPC). Storage moduli of the hydrogels prepared at 1:1, 1:2, and 1:4 keratose to THPC reactive group ratios were measured as 63 ± 22, 291 ± 21, and 804 ± 53 Pa, respectively. Crosslinking degrees of the hydrogels also affected the secondary structures of the keratose films obtained from the drying of the hydrogels. The hydrogel with the highest crosslinking density (1:4 gel) exhibited the lowest swelling ratio, whereas the one with the lowest crosslinking density (1:1 gel) disintegrated in deionized water within less than 6 h. CCK-8 tests using L929 mouse fibroblast cells showed that all the hydrogels promoted cell proliferation. These results suggest THPC crosslinked hydrogels prepared at the millimolar THPC concentrations are biocompatible scaffolds, which can be utilized in drug delivery and tissue engineering applications. Graphical abstract: [Figure not available: see fulltext.]Article Citation - WoS: 7Citation - Scopus: 11Hydrophobic Deep Eutectic Solvent Effect on Acrylic Acid Separation From Aqueous Media by Using Reactive Extraction and Modeling With Response Surface Methodology(Taylor & Francis, 2022) Lalikoğlu, Melisa; Aşçı, Yavuz Selim; Sırma Tarım, Burcu; Yıldız, Mahmut; Arat, RefikHydrophobic deep eutectic solvents (HDES) are new-generation green solvents that have emerged in recent years. In this study, the efficiency of using HDES as a solvent in separating acrylic acid from its aqueous solution by reactive extraction method was investigated. As a solvent, HDES prepared with a mixture of TOPO and menthol has been used for the recovery of acrylic acid for the first time. Physical properties of HDES mixtures such as density, viscosity, and refractive index were determined. In reactive extraction experiments, TOPO, one of the two basic components in the solvent, was also employed as an extractant. With the help of response surface methodology based on Box-Behnken design, the effect of the parameters of amount of extractant (0.1–0.9 g), Menthol/TOPO molar ratio (2–4), and initial acid concentration (3–9%) on the distribution coefficient was investigated and the model equation was formed. The highest distribution coefficient (D = 7.8) was achieved with the molar ratio of Menthol/TOPO is 2. Upon examining all the results obtained, it was seen that more than 90% of acrylic acid could be extracted from the aqueous phase to the organic phase.