Browsing by Author "Alkan, Salih"

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Adsorption Equilibrium and Thermodynamics of Diatomite (caldiran/Van) Onsome Textile Dyes
(Chem Soc Pakistan, 2018) Alkan, Salih; Caliskan, Meliha; Irende, Ilhan; Kul, Ali Riza
Together with increasing world population, developing technology and rapid industrialization process bring about environmental pollution. Nowadays, cleaning environment from industrial wastes and pollutants is of utmost importance. Some organic materials, produced by the majority of textile waste, cause environmental pollution. Many dyestuffs, which are hazardous for environment, can be released to environment by industrial organizations without having any precaution. Textile dyestuffs, being above certain concentrations, can cause poisoning of aquatic organisms. Dyestuffs can be classified as following: Anionic: Direct, acid and reactive dyes Cationic: Basic dyes Nonionic: Disperse dyes It can be said that most problematic group of dyes used in the textile industry is the group of reactive dyes. Analyzing performed studies shows that these views are supported. Today, adsorption techniques are gaining ground due to efficiency in removal of too stable pollutants. Adsorption is, economically, a reasonable method and we can say that it provides formation of high quality products. With the development of industry search for materials, to be used as adsorbent for removal of factory wastes and water-soluable dyestuffs from water, accelerates. In our study, from natural adsorbents diatomite(Calthran/VAN) is used as an adsorbent material. The removal of natural red and basic blue from aqueous solution using diatomite, was investigated with respect to the adsorbent dose (0,02 g), initial concentration (20-140 mg/L), temperature (between 25 and 45 degrees C), on batch adsorption were studied as a function of contact time. The lineer Langmuir, Freundlich and Temkin adsorption equations were applied to describe the equilibrium isotherms. In addition, the pseudo-first-order, pseudo-second-order and intraparticle diffusion models were used to determine the kinetic data. The experimental data were well fitted by the pseudo-second-order kinetic model. Thermodynamic parameters such as the enthalpy (Delta,H degrees), Gibbs free energy (Delta G degrees) and entropy (Delta S degrees) shoved spontaneous and endothermic in nature of adsorption for both of adsorbents.
Adsorption of Catalase Enzyme on Silica Gel
(Asian Journal of Chemistry, 2007) Alkan, Salih
Immobilization of catalase enzyme on fibrous silica gel was investigated in present study. Simple adsorption has no effect on enzyme activity and appeared to as a new method of immobilizing the enzyme at high ionic strength. The storage stability and the kinetic parameters of immobilized enzyme and its activity were evaluated under varied pH, ionic strength and temperature. These studies indicate that silica gel is a valuable support for simple adsorption of enzymes.
Adsorption of Crystal Violet From Aqueous Solution on Activated Carbon Derived From Golbasi Lignite
(oficyna Wydawnicza Politechniki Wroclawskiej, 2012) Depci, Tolga; Kul, Ali Riza; Onal, Yunus; Disli, Erkan; Alkan, Salih; Turkmenoglu, Z. Funda
Activated carbon (AC) was obtained from lignite of the local resource, Golbasi - Adiyaman (Turkey) by chemical activation. The Golbasi lignite was chosen as the precursor for its availability and low cost. The BET surface area of the activated carbon was found 921 m2/g. The AC was used as an adsorbent for Crystal Violet (CV) in aqueous solution. The adsorption properties of CV onto the activated carbon are discussed in terms of the adsorption isotherms (Langmuir and Freundlich) and the kinetic models (pseudo-first-order, pseudo-second-order and intraparticle diffusion model). It was shown that the experimental results best fitted by the Langmuir model, and the second-order kinetic equation. The thermodynamic parameters show that the adsorption process is endothermic. The experimental results point out that the obtained activated carbon is a viable candidate for sorbent removing CV from aqueous solutions.
Adsorption of Textile Dyes From Aquous Solutions by Using Kiwifruit (Ordu) Peel
(Parlar Scientific Publications (p S P), 2017) Alkan, Salih; Kul, A. Riza; Yagiz, Adem
In this study, kiwifruit (kiwi) peel was used as adsorbent for the adsorption of dying reagents methylene blue and Rhodamine B. Effects of pH, starting dye concentration, temperature, and equilibrium contact time on the bio-sorption of methylene blue and Rhodamine B were investigated. Data were applied to Lagergren, Ho-Mckay, Weber -Morris kinetic models and the Langmuir and Freundlich adsorption isotherms. It was found that the adsorption isotherms follow the Langmuir model. However, the adsorption kinetics follow Ho-Mckay and Freundlich models for methylene blue and Rhodamine B, respectively. The isotherm data obtained at different temperatures for biosorption of methylene blue and Rhodamine B were applied to thermodynamics equations and thermodynamic parameters (Delta G, Delta H, and Delta S).
Adsorption of Textile Dyes on Willow Tree Pollen: Determination of Equilibrium, Kinetics, and Thermodynamic
(Jihad Daneshgahi, 2022) Alkan, Salih; Karakoc, Emel; Ilhan, Hasan; Caliskan, Meliha; Savran, Ali; Kubilay, Senol
In this study, the characterization and adsorption properties of Brilliant Cresyl Blue (BCB- ALD) and Acid Blue-25 (AB-25) dyes were investigated using willow tree pollen, a low-cost natural adsorbent. All adsorption tests were performed in consideration to contact time, adsorbent concentration, adsorbent dosage, and temperature functions. Equilibrium isotherms were explained in terms of the Langmuir, Freundlich, Temkin, and Dubinin Radushkevich (D-R) linear adsorption equations. It was found that adsorption complied with the Langmuir equation. Moreover, pseudo-first order, pseudo-second order, and intraparticle diffusion models were used to determine kinetic data. Experimental data showed a match with the pseudo-second-order kinetic model. Thermodynamic parameters such as enthalpy, Gibbs free energy, and entropy were examined for willow tree pollen samples. The data obtained led us to the conclusion that adsorption is a spontaneous process. On the other hand, positive enthalpy indicates that adsorption is endothermic. Positive entropy values are a result of changes on the adsorbent surface. Characteristic results and dimensionless separation factors (RL) indicate that pollen can be used as an alternative to commercial adsorbents to remove BCB- ALD and AB-25 from aqueous solution and wastewater.
Adsorption of Zinc(Ii) on Diatomite and Manganese-Oxide Diatomite: a Kinetic and Equilibrium Study
(Elsevier, 2011) Caliskan, Necla; Kul, Ali Riza; Alkan, Salih; Sogut, Eda Gokirmak; Alacabey, Ihsan
The removal of Zn(II) ions from aqueous solution was studied using natural and MnO2 modified diatomite samples at different temperatures. The linear Langmuir, Freundlich and Dubinin-Radushkevich (D-R) adsorption equations were applied to describe the equilibrium isotherms. From the D-R model, the mean adsorption energy was calculated as >8 kJ mol(-1), indicating that the adsorption of Zn(II) onto diatomite and Mn-diatomite was physically carried out. In addition, the pseudo-first-order, pseudo-second-order and intraparticle diffusion models were used to determine the kinetic data. The experimental data were well fitted by the pseudo-second-order kinetic model. Thermodynamic parameters such as the enthalpy (Delta H-0), Gibbs' free energy (Delta G(0)) and entropy (Delta S-0) were calculated for natural and MnO2 modified diatomite. These values showed that the adsorption of Zn(II) ions onto diatomite samples was controlled by a physical mechanism and occurred spontaneously. (C) 2011 Elsevier B.V. All rights reserved.
Characteristic Properties of Adsorbed Catalase Onto Activated Carbon Based Adiyaman Lignite
(Parlar Scientific Publications (p S P), 2011) Depci, Tolga; Alkan, Salih; Kul, Ali Riza; Onal, Yunus; Alacabey, Ihsan; Disli, Erkan
Catalase is one of the most common and important enzymes in biological systems. However, its purification process has some difficulties and it can be easily decomposed in aqueous or nonaqueous solutions. Therefore, a catalase should be adsorbed on solid materials to reduce its inactivation and to increase its economic value. Activated carbon which was obtained from Turkish low-rank coal (Golbasi-Adiyaman) by chemical activation was used as a solid carrier to adsorb catalase for the first time in this research. The pore structure of the activated carbon was determined by A Tri Star 3000 (Micromeritics, USA) surface analyzer and scanning electron microscope. In order to determine adsorption properties of catalase, ionic strength effect, temperature-activity, pH-activity, storage stability and operational stability of the activated carbon were investigated. The kinetic and thermodynamic mechanisms of adsorbed enzyme were also studied. The experimental results pointed out that the obtained activated carbon is a viable candidate for an alternative solid carrier for catalase and it may be a promising material for various biotechnological applications.
Copper Removal From Wastewater Using Natural Pumice
(Health & Environment Assoc, 2015) Kul, Ali Riza; Alkan, Salih; Ocak, Sevda; Benek, Veysel
This study was conducted on the pumice supplied from the Van Province, Turkey. The physicochemical properties of CuCl2 at pH 5 were studied and the analyses were performed at a temperature of 308 degrees K at various concentrations (75 ppm, 100 ppm, 125 ppm) of Cu(II). In this study, we aimed to investigate the adsorption behavior between the Van pumice and Cu(II).
Effects of Some Drugs on Enzyme Activity of Catalase From Bovine Liver (Vol 18, Pg 601, 2006)
(Mrs Pushpa Agarwal, 2006) Alkan, Salih; Savran, Ali; Demir, Halit; Ceylan, Hasan
Statistical Modeling of Cobalt Adsorption on Van Pumice
(Modestum Ltd, 2018) Kul, Ali Riza; Keskin, Siddik; Demir, Canan; Alkan, Salih
The aim of this study is to statistical modeling of cobalt adsorption on Van Pumice. Van Pumice was used for determination of cobalt adsorption level. Modeling, depending on time, was performed to determine for cobalt adsorption level at fixed pH 5 for various concentration and temperatures in Van pumice. All adsorption measurements were performed with the Thermo Scientific brand ICE spectrometer model 300 Series. One-way analysis of variance was used for comparison to various temperature and concentration levels. Tukey's multiple comparison test was also performed to determine different groups. Logarithmic, quadratic, Qubic and logistic models as well as linear were used to determine adsorbed cobalt amount at different temperature levels and heavy metal concentration. Differences between various time and temperatures levels were found statistically significant, however, there were no significant differences between time level. R-2 values of the models ranged from 70% to 99%. In addition, cubic model had higher R-2 values for each concentration and temperature levels. Cobalt concentration and amount of ions have been increased in the solution. The performance of all models to determine the amount of adsorption of cobalt has been significantly found. However, model the best performance has been shown with the cubic.
Statistical Modeling of Copper Adsorption on Van Pumice
(Iser Publications, 2017) Demir, Canan; Keskin, Siddik; Kul, Ali Riza; Alkan, Salih
Copper (Cu) is an element which is essential for the living. In addition, copper is also one of the first metals used by humans and occurs naturally in nature. The aim of this study is to statistical modeling of copper adsorption on Van Pumice. Van Pumice was used for determination of copper Adsorption level. Modeling, depending on time, was performed to determine for copper adsorption level at fixed pH 5 for various concentration and temperatures in Van pumice. All adsorption measurements were performed with the Thermo Scientific brand ICE spectrometer model 300 Series. One-way analysis of variance was used for comparison to various temperature and concentration levels. Tukey's multiple comparison test was also performed to determine different groups. Logarithmic, quadratic, Qubic and logistic models as well as linear were used to determine adsorbed cooper amount at different temperature levels and heavy metal concentration. Differences between various time and temperatures levels were found statistically significant, however, there were no significant differences between time level. R-2 values of the models ranged from 70% to 99%. In addition, cubic model had higher R-2 values for each concentration and temperature levels. Copper concentration and amount of ions have been increased in the solution. In addition, Copper ions adsorption level increased with extending of contacting duration by Van Pumice In addition, adsorption also increased linearly with mixing duration and this increase was ready in the first minutes and then stabilized. The performance of all models to determine the amount of adsorption of copper has been significantly found. However, model the best performance has been shown with the cubic.
Studing Catalaz Enzyme Adsorbtion and Kinetix on Natural and Modify Active Carbons That Optain From Walnut in Various Methods
(2009) Ertan, Mehtap; Alkan, Salih
Bu çalışmada aktif karbon üzerine katalaz enziminin (E.C.1.11.1.6) adsorpsiyonu ve sabit pH da (pH=7) inkübasyon süresi araştırıldı.Adsorpsiyon için optimum şartları belirlemek amacı ile pH, sıcaklık, iyonik şiddet ve enzim kil oranı ve asitle muamele gibi parametrelerin etkileri ayrı ayrı değerlendirildi. Endüstiriyel üretimde kullanılacak immobilize enziminin kararlılığını tespit etmek için, adsorbe-enzim (aktif kömür) miktarının aktivitesini, iki ay süresince (60 gün) %76,8 oranında koruduğu belirlendi. Bazı hallerde enzimler, en yüksek etkinliği belirli bir pH aralığında gösterirler. Enzim immobilizasyonundan sonra enzimin optimum pH değerinde kayma gözlendi. Serbest enzimin pH'sının 7 olduğu, inmobilize enzimin optimum pH'sının 7-8 arasında ve asitle muamele edilmiş aktif kömürün pH'sının 6 civarında olduğu tespit edilmiştir.Çalışmanın ikinci aşamasında serbest ve immobilize enzimler için Km ve Vmax değerleri, değişik konsantrasyonlarda substrat çözeltileri kullanılıp, enzim aktivitelerinden 1/S ve 1/V değerleri bulunarak Lınewearver-Burk grafiklerinden belirlendi.En son aşama olarak kil asitle muamele edildi. Asitle muamele görmüş kil ile saf enzim immobilize edildikten sonra birinci ve ikinci aşamada yapılan işlemler tekrar edildi.Bütün aktivite tayinleri 240 nm'de Ultraviyole Spektroskopisi ile yapıldı.Yapılan bu çalışmada aktif kömürün, iyonik şiddet etkisi altında iyi bir tutucu olabileceği kanısına varıldı.Anahtar Kelimeler: Katalaz enzimi, Aktif Karbon, Adsorpsiyon
The Adsorption of Polyphenoloxidase Enzyme on the Active Carbon Derived From Hazelnut Crust and Analysing Its Kinetics
(2012) Erol, Necmi; Alkan, Salih
Bu çalışmada Trabzon yöresinden alınan fındıkkabukları ZnCl2, HCl ve KOH ile aktive edilerek elde edilen aktif karbon üzerine polifenoloksidaz enziminin adsorpsiyonu incelenmiştir.Faklı pH(3, 4, 5, 6, 7, 8, 9), farklı sıcaklıklarda (20, 30, 40, 50, 60, 70, 80 0C )ve derişimlerde(0.1, 0.2, 0.3, 0.4 M) çalışmalar yapılmıştır. Lagergrenyalancı birinci dereceden hız denklemi dikkate alınarak adsorban maddenin adsorplama gücünün bir ölçüsü olan q1 ve k1 değerleri elde edilmiştir.Termodinamik parametrelerden adsorpsiyon entalpisi (?H), Gibbs serbest entalpisi (?G) ve adsorpsiyon entropisi (?S) değerleri hesaplanmıştır.Sonuç olarak elde edilen verilerden, en iyi adsorpsiyon mekanizmasının ZnCl2 ile hazırlanan aktif karbon örneğine ait olduğu tespit edilmiştir.
Thermodynamic Study of Activated Carbon From Pear Shell and Acacia Tortilis Reactions With Immobilized Lipases
(Parlar Scientific Publications (p S P), 2018) Alkan, Salih; Turgut, Unit; Irende, Ilhan; Kul, Ali Riza
Lipases perform essential roles in the digestion, transportation and processing of the dietary lipids. The properties of the clay activated carbon (pear shell) and acacia tree (acacia tortilis) as a support for enzyme immobilization were studied using the enzyme lipase. The Km and Vmax values of the butyrate hydrolysis were determined, respectively. The free and immobilized ones on activated carbon and acacia tortilis lipase was determined to be the most active in mildly alkaline conditions (pH 8.0-9.0) and in the temperature range of 40-50 degrees C. Taking in the account the Lagergren Firs-order equation for adsorption kinetics, q1 and k1 which are the measure of adsorbed assets strength have been carried out. Thermodynamic parameters Delta G0, Delta H0 and Delta S0 were calculated.
Türkiye'de Yenilen Bazı Yabani Mantarlarda Bazı Besin İçerikleri ve Ağır Metal Birikiminin Değerlendirilmesi
(2023) Uzun, Yusuf; Alkan, Salih; İrende, İlhan; Ilhan, Hasan; Çavuşoğlu, Şeyda; Aslan, Ali
Bu çalışmada, Türkiye'de iki farklı bölge ve lokalitelerinden toplanan yenilebilir yabani bazı mantar örneklerinin teşhis edilmesi ve ardından ağır metal ve besin içeriklerinin belirlenmesi amaçlanmıştır. Bu mantarların dördü (Coprinus comatus (O.F. Müll.) Pers, Cantharellus cibarius Fr, Pleurotus ostreatus (Jacq.) P. Kumm. ve Lactarius glyciosmus (Fr.) Fr.) yakın yerleşim yerlerinden, diğerleri ise (Hydnum repandum L., Pleurotus eryngii (DC.) Quél ve Lactarius deliciosus (L.) Gray) kırsal alanlardan toplanmıştır. Tüm türler yerel halk tarafından tanınmakta ve besin amaçlı tüketilmektedir. Teşhis edilen tüm türlerin, trofik durumları, habitatları Türkçe adları ve yenilebilirlikleri ile birlikte verilmiştir. Element konsantrasyonları kuru ağırlığa göre belirlenmiştir. Analiz edilen mantar türlerinden elde edilen sonuçların farklılık gösterdiği belirlenmiştir. Sonuçlara göre; As (nd, 1,5-17,43), Ba (1,48-10,81), Cd (nd, 1.4-43.46), Co (Nd, 12.0- 42.79), Cr (nd, 5.0-14.92), Cu (12.95-143.45), K (nd, 30085- 52680), Mg (nd, 5056-5955.9), Mn (52.45- 187.25), Mo (nd, 1.22-57.53), Ni (43.46-565), Pb (318.9-1483.5), Sb ( nd, 0.14-4.12), Si (nd, 3.18-87.83), Ti (20.32-302.2), V (67.66-102.3), Zn (1026.8-2422.0), Ca (411.5 -2077), Na (752.5-2105.5) ve Fe (470.5-1093.5) belirlenmiş ve incelenen elementler mg/kg olarak verilmiştir. Sonuç olarak, ağır metaller bakımından en düşük değere sahip mantarlar: C. comatus, H. repandum, C. cibarius ve P. eryngii, kalsiyum ve magnezyum içeriği bakımından ise en yüksek değere ise P. ostreus'un sahip olduğu belirlenmiştir. Dolayısıyla bu mantar türlerinin insan sağlığı açısından önemli potansiyele sahip olduğu görülmektedir. Daha sonra yapılacak ilgili çalışmalarda kaynak olarak kullanılabileceği düşünülmektedir.