Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleAçık Erişim2026Obtaining Natural Dye from Oak Tree and Examination of Dyeing Properties According to Different Methods
Fırat, Tülay
This study investigates the dyeing performance of a natural dye extracted from the branches and leaves of the oak tree (soredar) on muslin fabric. The plant materials were soaked in water for 24 h and subsequently boiled to obtain the dye extract. Dyeing experiments were conducted using conventional dyeing methods with and without mordanting. Copper sulphate, iron sulphate, and potassium dichromate were used as mordants to evaluate their influence on the dyeing behavior of the fabric. The color properties of the dyed samples were determined using spectrophotometric measurements based on the CIELab color system, and color strength (K/S) values were calculated using the Kubelka–Munk equation. In addition, the durability of the dyed fabrics was assessed through washing, rubbing, and light fastness tests according to relevant ISO standards. The results revealed that the type of mordant significantly affected both color strength and fastness performance. Among the tested mordants, copper sulphate produced the highest color strength, while iron sulphate also improved dye uptake compared with the non-mordanted sample. Overall, the findings demonstrate that oak-derived natural dye can be effectively applied to muslin fabric and that mordanting plays a crucial role in enhancing the color depth and durability of natural dyeing processes.
- MakaleYalnız künye2026Scopus SJRQ2Adsorption of Reactive Red 120 dye from aqueous solutions using sepiolite clay with a channel-structured morphology: Mechanism, kinetics, isotherm, and thermodynamic studies
Fırat, Tülay
The effective treatment of dye-containing wastewater remains a major environmental challenge due to the high stability and solubility of reactive dyes. In this study, the adsorption behavior of Reactive Red 120 (RR120), an anionic reactive azo dye, from aqueous solutions was investigated using natural sepiolite clay possessing a channel-structured morphology. Batch adsorption experiments were performed to evaluate the effects of contact time (1–200 min), initial dye concentration (50–500 mg L−1), adsorbent dosage (0.1–1.5 g), solution pH (2–10), and temperature (25–50°C). The adsorption equilibrium was reached within approximately 75 min. The Langmuir isotherm provided the best fit to the equilibrium data, yielding a maximum monolayer adsorption capacity of 168.4 mg g−1 at 298 K. Thermodynamic analysis revealed that the adsorption process was spontaneous and endothermic, with an activation energy of 32.41 kJ mol−1. Adsorption kinetics were analyzed using pseudo-first-order, pseudo-second-order, and intraparticle diffusion models, while equilibrium data were evaluated using Langmuir, Freundlich, and Temkin isotherm models. The kinetic data were best described by the pseudo-second-order model, while thermodynamic analysis revealed that the adsorption process was spontaneous and endothermic. FTIR and XRD analyses further supported the important role of the channel-structured framework of sepiolite in RR120 adsorption. Unlike many clay-based adsorbents that require chemical modification, natural sepiolite exhibited high adsorption performance due to its intrinsic fibrous morphology, nano-channel structure, and high surface area. These findings demonstrate that natural sepiolite is a promising, low-cost, and sustainable adsorbent for the treatment of dye-contaminated wastewater.
- MakaleAçık Erişim2025Atık Polietilenteraftalat (PET) Geri Dönüşümünden Elde Edilen Glikolize Ürünler ile Sentezlenen Reçinelerin Poliolefinlerin Akışkanlığı ve Yoğunluğuna Etkileri
Kismet, Yilmaz; Fırat, Tülay
Yapılan bu çalışmada, atık polietilen tereftalat (PET) glikolize edildi ve elde edilen oligoester poliollerden reçine sentezlendi. Atık PET’ in depolimerizasyonu, üç faklı glikol (Polipropilen Glikol (PG), Trietilen Glikol (TEG) ve Polietilen Glikol (PEG)) (1:2) ve (1:10) molar oranlarında iki farklı katalizör (çinko asetat, çinko sülfat) eşliğinde gerçekleştirildi. Reçine sentezi için öncelikle, glikolize ürün ve maleik anhidrit (1:1) molar oranınında karıştırıldı ve daha sonra bu karışıma, kobalt oktoat ve metil etil keton peroksit (MEKPO) eklendi. Sentezlenen reçine farklı oranlarda alınarak termoplastik polimerlerin önemli bir grubu olan poliolefinlerde dolgu maddesi olarak değerlendirildi. Aynı zamanda önemli birer ticari termoplastik olan alçak yoğunluklu polietilen (AYPE), yüksek yoğunluklu polietilen (YYPE), polipropilen (PP) reçineye farklı oranlarda eklenerek dolgu maddesi elde edildi. Elde edilen dolgu maddelerinin kütlesel akış indeksi ve yoğunluk analizleri gerçekleştirildi. Geliştirilen dolgu maddesinin özellikle YYPE ve PP başta olmak üzere her üç termoplastiğinde kütlesel akışkanlığını iyileştirdiği tespit edildi.
- MakaleYalnız künye2025Scopus SJRQ2Chromium removal with walnut shells and oak branches, adsorption studies, and kinetics
Fırat, Tülay
This study investigates the chromium sorption properties of walnut shells (WS) and oak branches (OB), both of which were modified using NaOH and lactic acid treatments. The characterization of these adsorbents was carried out using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), point of zero charge (pHpzc) analysis, and Brunauer–Emmett–Teller (BET) surface area measurements. According to BET results, WS exhibited higher surface area values compared to OB. The pH and pHpzc measurements revealed that acidic functional groups are more prevalent than basic ones on both adsorbents. Batch experiments were conducted to evaluate the chromium ion sorption capacities of WS and OB. To further understand the adsorption mechanism, the Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) isotherm models were analyzed, with the Langmuir and Freundlich models being widely recognized for describing adsorption in single-solute systems. The equilibrium data aligned best with the Langmuir isotherm, while the kinetic data were modeled using pseudo-first-order and pseudo-second-order kinetics. The maximum chromium sorption capacity for WS was determined to be 30.51 mg/g. The energy values calculated from the D-R equation for chromium adsorption onto WS and OB were 13.49 kJ/mol and 15.71 kJ/mol, respectively, indicating that the adsorption process is primarily driven by physical adsorption.
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İncele - MakaleYalnız künye2024Scopus SJRQ2Degradation Products of Rhyolitic Rocks, Adsorption Applications, Isotherm Studies
Fırat, Tülay; Sarıcı-Özdemir, Çiğdem
Heavy metals and their toxicity are a major global concern. They are one of the major environmental problems causing serious problems for living beings. In this study, the adsorption properties of a clay sample located in nature are improved by treating with different materials, and then adsorption properties are examined. It is observed that clay sample can be used in many adsorption applications, including the adsorption of heavy metals such as copper. The clay mineral used in the study was obtained from a rhyolite type rock. Rhyolite rocks, one of the degradation products of volcanic rocks, are the volcanic counterparts of granite. In this study, rhyolite rock was crushed with suitable crushers and grinders, then sieved under 200 mesh with molecular sieve and clay minerals were obtained. The clay samples (K1,K2. K8) were synthesized by subjecting clay with acid and base. Adsorption properties of clay are due to wide surface area, surface functional groups and microporosity. Adsorption of methylene blue and iodine, adsorption from aqueous solutions of copper are done with clay samples and results were compared with samples of clay have not undergone any pre-treatment. In the study, the highest adsorption capacity was determined by applying the Freundlich isotherm. In the K6 sample treated with a base, the highest adsorption capacity was calculated as 26.98 Lg−1. In contrast, the Langmuir isotherm results were calculated in the range of 10.56 to 11.86 Lg−1. This indicates that the adsorption takes place on a heterogeneous surface. The structure and surface properties of clay were examined.
AtıfScopus2WoS2OpenAlex2İncele - MakaleAçık Erişim2023Scopus SJRQ3Evaluation of waste polyethylene terephalate in polyol and polyurethane production
Fırat, Tülay; Kar, Filiz
As technology advances and human population grows, we must meet our diverse needs while minimising harm to the environment. One solution is to prioritise recycling and using second-hand consumer goods. In this study, PET flakes were depolymerised by glycolysis using different molar ratios of glycol such as propylene glycol(PG), triethylene glycol(TEG) and polyethylene glycol(PEG 400) in the presence of two different catalysts: zinc acetate- zinc sulphate. As a result, glycated products (polyols-PO) were obtained. The obtained polyols were then used to synthesise polyurethane films (PU) via acetone process. The thermal and chemical characterisations of the polyurethane films (PU) were analysed. In similar studies, zinc acetate was used as a transesterification catalyst for the glycolysis process. In this study, the same process was carried out using zinc sulphate and zinc acetate. Zinc sulphate was found to be a cheaper and eco-friendlier catalyst alternative to zinc acetate for the glycolysis process.
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