Sürdürülebilir Kalkınma Amaçları

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Araştırmacılar(11)

• Akkus, Sukran
• Aslan Sungur, Guler
• Ayhan, Nagihan Karaaslan
• Bahar, Nurdan
• Bal, Tulin
• Boztug, Ali
• Kiliç, Fatih
• Sarici-Özdemir, Cigdem
• Tanaydin, Mehmet Kayra
• Yalcinkaya, Eylem
• Yaman, Mehmet

• MakaleYalnız künye2021Scopus SJRQ2/r/munzur/2926
  Recovery of Cu(II) by Acorga M5640 After Leaching of Malachite Ore in Perchloric Acid Solutions

  Demirkıran, Nizamettin; Tanaydın, Mehmet Kayra

  Abstract: In the present study, the recovery of Cu2+ from the resulting actual leach solution after the leaching of malachite ore in perchloric acid solutions was examined by applying the solvent extraction method. The organic phase was prepared using Acorga M5640 and kerosene. The effects of the initial pH of solution, extractant concentration, Cu2+ concentration, temperature, and stirring speed on the extraction process were investigated. It was determined that the extraction yield increased with an increase in the extractant concentration, initial pH of aqueous solution, stirring speed, and temperature, and with a decrease in the concentration of Cu2+. To prevent or minimize Zn2+ transfer to the organic phase and to ensure maximum Cu2+ extraction from the aqueous phase, the optimal values for the initial pH of the aqueous phase, initial concentration of Cu2+, extractant concentration, temperature, and stirring speed were selected to be 1, 0.152 g/L, 4% (v/v), 25 °C, and 400 rpm, respectively. The stoichiometry and mechanism of the extraction process were determined applying the equilibrium slope method. The changes in the Gibbs free energy, enthalpy, and entropy were determined. The changes in these thermodynamic parameters were calculated to be − 3.87 kJ/mol, 64.67 kJ/mol, and 0.23 kJ/(mol K), respectively. Graphical Abstract: The extraction percentage of Cu2+ increases substantially when the initial pH of the leach solution increases from 0.1 to 1. The further increase in the initial pH above 1 does not create an increase in the extraction extent of Cu2+. When the initial pH of the leach solution is higher than 1, the amount of Zn2+ transferred from the aqueous phase to the organic phase increases significantly.[Figure not available: see fulltext.].

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  AtıfScopus7·WoS5·OpenAlex9

  İncele
• MakaleYalnız künye2020Scopus SJRQ3/r/munzur/3276
  Kinetic models for the extraction of copper by Acorga M5640 after leaching of malachite ore in perchloric acid solutions and the stripping of copper from loaded organic phase

  Tanaydın, Mehmet Kayra; Demirkıran, Nizamettin

  In the present work, the extraction kinetics of copper using the resulting actual leach solution obtained from the leaching of malachite ore in perchloric acid solutions and the stripping kinetics of copper from the loaded organic phase were examined. The organic phase was prepared by using Acorga M5640 and kerosene. In the extraction process, the effects of the initial pH of aqueous solution, initial concentration of copper, extractant concentration, temperature, and stirring speed on the extraction rate were investigated. In the stripping process, the effects of the concentration of perchloric acid, temperature, stirring speed, and extractant concentration on the stripping rate were examined. It was determined that the extraction rate increased with increasing the initial pH of aqueous solution, stirring speed, extractant concentration and temperature, and with decreasing the initial concentration of copper ions. In the stripping process, it was observed that the stripping rate increased with increasing the concentration of perchloric acid, temperature and stirring speed, and with decreasing the extractant concentration. It was determined that both the solvent extraction and stripping processes could be described by the first order pseudo homogenous reaction model. The activation energy for the extraction and stripping processes was calculated to be 50.04 kJ/mol and 32.42 kJ/mol, respectively.

  AtıfScopus8·WoS7·OpenAlex10

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• MakaleYalnız künye2019Scopus SJRQ4/r/munzur/3836
  Application of response surface methodological approach to optimize removal of Cr ions from industrial wastewater

  Ince, Muharrem; Ince, Olcay Kaplan

  In the present study, the adsorption of chromium (Cr) onto clay using response surface methodology (RSM) was investigated as an efficient approach for examining predictive model building and optimization. To optimize experimental variables and predictive regression models, statistical design models were carried out. A five-level four-fac-tor central composite design (CCD) combined with RSM was performed with synthetic aqueous solutions on natural clay. The experimental variables included pH and agitation speed and were selected for optimization. The Cr ions ideal removal conditions were obtained using pH 5.0, contact time 23.0 minutes, adsorbent dosage of 69.4 mg, and agitation speed of 135 rpm. Chromium removal efficiency was found at 23.16 mg g-1. The independent variables significance and their interactions were verified by means of the analysis of variance (ANOVA). These results were justified by the relatively high correlation coefficients (R2 = 0.9902) of the statistical prediction. Clay and Cr loaded clay were characterized by X-ray dif-fractometer (XRD) and energy dispersive spectroscopy (EDS). The proposed adsorption process efficiently removed the Cr ions present in various aqueous media and was also applied to various industrial wastewaters.

  AtıfScopus5

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• MakaleYalnız künye2019Scopus SJRQ2/r/munzur/3708
  Investigation of selective leaching and kinetics of copper from malachite ore in aqueous perchloric acid solutions

  Tanaydın, Mehmet Kayra; Demirkıran, Nizamettin

  In this study, the leaching kinetics of malachite in perchloric acid solutions was investigated. The dissolution behaviors of copper, zinc, and iron in the ore matrix were determined at different acid concentrations and reaction temperatures. It was observed that the concentration of perchloric acid had a major effect on the dissolution of copper, zinc, and iron. It was determined that the effect of temperature on the dissolution of these species was not as significant as concentration impact. The results obtained shown that copper in the ore matrix was completely leached while zinc and iron were partially dissolved in perchloric acid solutions. In addition, the effects of the acid concentration, reaction temperature, stirring speed, particle size, and solid-to-liquid ratio on the leaching of malachite were researched. In these experiments, it was observed that the leaching rate of copper increased with increasing solution concentration, stirring speed, and reaction temperature, and with decreasing solid-to-liquid ratio and particle size. A kinetic analysis was performed, and it was found that the rate of leaching reaction obeyed the mixed kinetic control model in the unsteady state. The activation energy of the leaching process was calculated to be 34.69 kJ/mol.

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  AtıfScopus19·WoS16·OpenAlex20

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• MakaleYalnız künye2019Scopus SJRQ2/r/munzur/3443
  A comprehensive study about Hibiscus sabdariffa leaves: antioxidant activity, polyphenol profile and macro- and micro-element content

  Karaaslan, Nagihan M.

  Hibiscus sabdariffa leaves are generally consumed by people in cold drinks and herbal tea. The purpose of this study is to examine in terms of antioxidant activity, polyphenol profile and macro- and micro-element content of H. sabdariffa leaves. Firstly, antioxidant activity studies were carried out by applying antioxidant activity assays to different extracts of the plant leaves. It has been observed that the antioxidant activity results vary depending on the extraction solvent and that the result obtained for one extract in some tests could not be obtained for the same extract in the other tests when solvents are changed. Secondly, the polyphenol profile of this plant was identified with a high-performance liquid chromatography–diode array detector (HPLC–DAD). For this purpose, thirteen polyphenols were examined in leaves of this plant, but only caffeic acid, chlorogenic acid, ellagic acid, p-coumaric acid and quercetin were detected among the studied polyphenols. Finally, macro-element including calcium (Ca), potassium (K), magnesium (Mg), sodium (Na) and micro-element including copper (Cu), iron (Fe), zinc (Zn) analysis was carried out using flame atomic absorption spectrometry (FAAS).

  AtıfScopus9·WoS8·OpenAlex10

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• MakaleAçık Erişim2019Scopus SJRQ4/r/munzur/3392
  Modeling approach with Box-Behnken design for optimization of Pb bioaccumulation parameters in Gammarus pulex (L., 1758)

  Pala, Aysegul; Serdar, Osman; Ince, Muharrem; Onal, Ali

  The aim of this research was to evaluate the suitability of Gammarus pulex (L., 1758), an amphipod crustacean, as a bio-monitor for lead (Pb). A Box– Behnken experimental approach combined with response surface modeling (RSM) and quadratic programming was employed to increase the knowledge about Pb2+ bioaccumulation in Gammarus pulex (L., 1758). Independent variables, such as temperature ranging from 18 to 22 ºC, contact time from 8 to 48 hours, and Pb2+ ion solution concentrations from 50 to 100 µg L-1, were studied and tested using analysis of variance (ANOVA). The standardized effects of the independent variables and their interactions on the dependent variable were also investigated according to a Pareto chart. The selected variables' optimum values were obtained by solving the quadratic regression model along with analyzing the response surface contour plots. Optimum experimental conditions were obtained at 22.0 ºC, contact time of 8 hours, and Pb concentration at 69.5 µg L-1. Based on the Box-Behnken design, the applied model is significant because the model F-value and R2 were obtained at 77.80 and 0.9901, respectively. Bioaccumulation of Pb was determined using electrothermal atomic absorption spectrometry (ETAAS). The obtained data suggest that G. pulex can be used as a Pb biomonitor.

  AtıfScopus4·WoS6·OpenAlex6

  İncele
• MakaleAçık Erişim2019Scopus SJRQ2/r/munzur/3337
  Optimization of microwave apple drying using response surface method; [Yanit yüzey metodu kullanarak mikrodalga ile elma kurutmanin optimizasyonu]

  Yoǧurtçu, Hakan

  In this study, the effects of microwave output power and slice thickness on microwave drying of apple slices were studied by using response surface method (RSM) in a modified domestic microwave oven. For experimental design, the central composite rotatable design approach was used. The values of response variables, effective diffusion coefficient, drying rate constant, color change, Hue angle, total drying time and energy consumption, were determined from the experiments performed under design conditions. It was seen that the obtained second order polynomial equations successfully represent the response variables. The results of analysis of variance (ANOVA) and response surface curves revealed that microwave output power and slice thickness were significantly effective on response variables. The effects of the independent variables on the responses and the significance level of these effects were evaluated statistically and the optimum drying conditions were determined for the aims of min color change, total drying time, energy consumption and max Hue angle. Verification experiments were performed with a maximum of 9.54% error at the recommended optimum test conditions. It has been shown that the response surface method can be successfully applied in the microwave drying of apples.

  AtıfScopus6·WoS5·OpenAlex3·TR Dizin3

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• MakaleAçık Erişim2019Scopus SJRQ2/r/munzur/3251
  Using Box–Behnken design approach to investigate benzo[a]anthracene formation in smoked cattle meat samples and its’ risk assessment

  Kaplan Ince, Olcay; Ince, Muharrem

  In present study, a novel approach was selected for benzo[a]anthracene determination from smoked cattle meat samples using solid phase extraction under various experimental conditions. To optimize experimental variables, a three factor, three-level Box–Behnken experimental design combining with response surface methodology and quadratic programming were employed to prevent excessive amount of benzo[a]anthracene formation in smoked meat based on different experimental parameters. The influence of some important process parameters including cooking time (10–30 min), fat ratio (5–25%) and distance to the cooking source (5–25 cm), which significantly affected the formation efficiency of benzo[a]anthracene were optimized. The analysis of variance was conducted for specifying the interactions of independent variables. The independent and the dependent variables interactions were investigated. The quadratic regression model and the response surface contour plots were used to determine optimum values for the selected variables. The results of study revealed that optimum cooking time of smoked cattle meat was determined as 24.9 min, fat ratio 7.9% and the distance to the cooking source 21.8 cm. Under optimum conditions, minimum benzo[a]anthracene was formed in meat and its amount was determined using high performance liquid chromatography-mass spectrophotometer as qualitative and quantitative. The limit of detection and limit of quantitation values were calculated as 0.4 µg kg −1 and 1.1 µg kg −1 , respectively.

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  AtıfScopus4·WoS4·OpenAlex8

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• MakaleYalnız künye2019Scopus SJRQ3/r/munzur/3243
  Determination of antioxidant capacity using different acidified solvents and element contents of Allium tuncelianum: A regional and varietal study on endemic edible garlic

  Karaaslan, Nagihan M.; Ince, Muharrem; Kaplan Ince, Olcay; Goksin Karaaslan, Merve

  Allium tuncelianum (Tunceli garlic), an endemic and threatened plant species in the Tunceli province of Eastern Turkey, is an important native source for local people. The antioxidant activities of the acidified extracts of water, acetonitrile, methanol, and ethanol of Allium tuncelianum were investigated using five antioxidant capacity tests. The results indicated that methanol extract efficiencies of garlic samples using the ABTS, CUPRAC, and reducing power capacities were higher than the other extracts. Water extract and acetonitrile extract values were highest for total phenolic content and metal chelating activities, respectively. Moreover, the element contents such as calcium (Ca), copper (Cu), iron (Fe), potassium (K), magnesium (Mg), manganese (Mn), sodium (Na), and zinc (Zn) of Allium tuncelianum samples digested by microwave and ashing ovens were determined by flame atomic absorption spectrophotometry and the results were compared statistically. The Ca, Cu, K, Mg, and Zn concentrations using the microwave method were found to be higher than the ashing procedure. However, the Fe, Mn, and Na concentrations using the ashing method were found to be higher than those using the the microwave protocol.

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  AtıfScopus7·WoS6·OpenAlex7

  İncele
• MakaleAçık Erişim2018Scopus SJRQ3/r/munzur/3974
  Dissolution kinetics of calcined ulexite in ammonium sulfate solutions

  Demirkiran, Nizamettin; Tanaydin, Mehmet Kayra; Özdemir, G. Deniz Turhan

  Ulexite is one of the boron minerals, which include a respectable amount of hydration water. It can be used as a raw material in the production of boron compounds. Some part of water in the composition of ulexite can be removed from the solid matrix applying dehydration treatment, and a porous structure can be obtained to increase the reaction rate. In the present study, the effect of dehydration temperature on dissolution kinetics of ulexite in ammonium sulfate solutions was researched in a batch reactor utilizing the parameters of solution concentration, solid-to-liquid ratio, stirring speed and reaction temperature. It was determined that the dissolution rate of calcined material increased with increasing solution concentration and reaction temperature and with decreasing solid-to-liquid ratio. The highest dissolution rate was attained with the sample calcined at 150 degrees C. It was found that the dissolution rate fit to the first order pseudo-homogeneous model. The activation energy of the dissolution process was estimated to be 42 kJ.mol(-1).

  AtıfWoS2·OpenAlex1

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