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Öğe A new donor-acceptor conjugated polymer-gold nanoparticles biocomposite materials for enzymatic determination of glucose(Elsevier Sci Ltd, 2020) Tan, Burcu; Baycan, FatmaIn this study, the monomer 3-(5,8-bis (2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl) -3-(9hexyl-9H-carbazole-3-yl) quinoxalin-2-yl)-9-hexyl9H-carbazole (HCQE) was electropolymerized on the graphite pencil electrode for the first time and used as a glucose biosensor. After electropolymerization, enrichment with Au nanoparticles was performed to amplify the signal (PHCQE/AuNPs). Following the electropolymerization step, glucose oxidase (GOx) immobilization was performed on the conjugated polymer coated graphite pencil electrode (GPE) surface using glutaraldehyde (GA) as crosslinking reagent due to strong pi-pi* conjugation on the polymer backbone (PHCQE/AuNPs/GOx). Voltammetric determination was also performed by monitoring the oxygen consumption against Ag/AgCl reference electrode at-0.7 V in phosphate buffer solution (0.10 mM; pH 7.4). The new PHCQE/ AuNPs/GOx biosensor showed a linear response for glucose in the concentration range between 0.75 and 3.125 mM (LOD: 0.017 mM) along with a good sensitivity (0.13 mu A/mM(-1)). To examine the selectivity of the PHCQE/ AuNPs/GOx biosensor, citric acid, fructose, sucrose, galactose, L-ascorbic acid, mannose, dopamine and salicylic acid were studied in the same buffer solution. The conjugated polymer PHCQE enriched with Au nano particles provides enzyme immobilization effectively. The applicability of the biosensor in the commercial samples has been also investigated and we have found that the conjugated polymer PHCQE enriched with Au nano particles is very effective for the determination of glucose in commercial samples.Öğe A novel PEDOT-derived electroactive polymer-based enzymatic glucose biosensor enriched with gold nanoparticles(Springer Science and Business Media Deutschland GmbH, 2023) Tan, Burcu; Baycan, FatmaIn this study, 3,4-ethylenedioxythiophene derivative conjugated monomer 4-(dihexylamino)-9,12-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-7H-benzo [de]benzo[4,5]imidazo[2,1-a]isoquinolin-7-one (EDOTBN) was synthesized and electropolymerized on pencil graphite electrode (PGE) to fabricate a highly stable and sensitive sensor for glucose detection for the first time. The structurally high conjugation of the monomer and the effect of increasing the conductivity of the gold nanoparticles increased the covalent bonding ability of the enzyme to the modified electrode surface and provided an excellent immobilization. PGE/p(EDOTBN)/AuNPs/GOx designed biosensor was characterized by a wide linear glucose determination range between 1.169 x 10-2 and 10 mM with a limit of detection of 0.008461 mM and a sensitivity of 38.365 mu A/mMcm2. Furthermore, the prepared bioelectrode showed storage stability for 4 weeks. Recovery studies were also carried out to check the accuracy of the developed bioelectrode and the glucose concentration in commercial samples was determined accurately.Öğe An Enzymatic Glucose Biosensor Based on a Pencil Graphite Electrode Modified with Naphthalenedimide/3,4-Ethylenedioxythiophene Conjugated Polymer and Enriched with Au Nanoparticles(Wiley-V C H Verlag Gmbh, 2022) Tan, Burcu; Baycan, FatmaN,N '-bis(2-hexyl)-2,6-(3,4 ethylenedioxythiophene)-1,4,5,8-naphthalenimide (ENDI) monomer was electropolymerized on pencil graphite electrode (PGE) and used as a biosensor for glucose immobilization for the first time. After electropolymerization of ENDI monomer on PGE (AuNPs/PENDI/PGE), the intensity of the current signal was improved by using gold nanoparticles (AuNPs). The immobilization of the glucose oxidase (GOx) enzyme was carried out by using the cross-linking reagent glutaraldehyde (GA) due to the strong pi-pi* interaction of the poly- N,N '-bis(2-hexyl)-2,6-(3,4 ethylenedioxythiophene)-1,4,5,8-naphthalenimide (PENDI) polymer. GOx/AuNPs/PENDI/PGE designed biosensor, was characterized by a wide linear glucose determination range between 0.0009-0.33 mM with a limit of detection of 0.0407 mM and a sensitivity of 0.172 mu A/mMcm(2). Herein we have shown that GOx/AuNPs/PENDI/PGE biosensor effectively provides the enzyme immobilization and very effective for glucose determination in commercial samples.Öğe ASSESSMENT OF ORANGE PULP DERIVED ACTIVATED CARBON AS AN ECO-FRIENDLY ADSORBENT IN REACTIVE BLUE 49 REMOVAL(Parlar Scientific Publications (P S P), 2022) Gunes, Sinem; Angin, Dilek; Ates, Asude; Tan, Burcu; Selengil, Ugur; Demirel, HulyaIn this study, activated carbon derived from orange (Citrus sinensis L.) pulp was used to remove Reactive Blue 49 from aqueous solutions. Activated carbon was produced by chemical activation method at an activation temperature 500 degrees C with a 3:1 impregnation ratio (ZnCl2 : orange pulp). The effects of various adsorption parameters (solution pH, activated carbon dosage, initial dye concentration, solution temperature, and contact time) on the dye removal were investigated. The maximum dye adsorption capacity (78.74 mg/g) was achieved at pH 2, with 0.4 g of adsorbent, an initial dye concentration of 100 mg/L, and a solution temperature of 45 degrees C. The equilibrium data were well defined by the Langmuir isotherm model, and the kinetic data exhibited the best fit with the pseudo-second-order model. Thermodynamic parameters indicated that the dye adsorption was endothermic and spontaneous.Öğe Boron rejection from aqueous solution and wastewater by direct contact membrane distillation(Yildiz Technical University, 2021) Tan, Burcu; Selengil, Uğur; Bektaş, Tijen EnnilBoron is widely used in various areas of modern technology. Due to the environmental problems arising during the production and use, the studies on the removal and recovery of boron from wastewater have been increased recently. Membrane distillation (MD) system is smaller in size with respect to other common distillation systems and needs lower operating temperatures. In addition, the equipment costs are reduced and the safety of the process increases since it operates at lower pressures. Moreover, the membrane distillation process can remove pollutants from water without using chemicals. In this study, boron rejection from aqueous solutions and wastewater was investigated by using direct contact membrane distillation (DCMD) system where both surfaces of a porous hydrophobic membrane were in contact with liquid streams. The effects of various parameters (pH, feed concentration, feed temperature, etc.) on boron rejection were investigated and the highest boron rejection was found to be 50 % when pH=10 at 50 °C and with feeding by a pump of 54 rpm. According to the test results of wastewater from Kırka Borax treatment plants, the mean distillate fluxes were found as 13, 16 and 14 L m-2 h-1 at the feed temperatures of 30, 40 and 50 °C, respectively. The boron removal percentages were found to be 47, 64 and 48 % at 30, 40 and 50 °C, respectively. It was observed in the XRD spectra that the crystals in wastewater mainly consist of Na2B(OH)4Cl and Mg2B2O5 structures.Öğe Boron Rejection from Aqueous Solution and Wastewater by Direct Contact Membrane Distillation(2020) Tan, Burcu; Selengil, Uğur; Bektaş, Tijen EnnilBoron is widely used in various areas of modern technology. Due to the environmental problems arising during the production and use, the studies on the removal and recovery of boron from wastewater have been increased recently. Membrane distillation (MD) system is smaller in size with respect to other common distillation systems and needs lower operating temperatures. In addition, the equipment costs are reduced and the safety of the process increases since it operates at lower pressures. Moreover, the membrane distillation process can remove pollutants from water without using chemicals. In this study, boron rejection from aqueous solutions and wastewater was investigated by using direct contact membrane distillation (DCMD) system where both surfaces of a porous hydrophobic membrane were in contact with liquid streams. The effects of various parameters (pH, feed concentration, feed temperature, etc.) on boron rejection were investigated and the highest boron rejection was found to be 50 % when pH=10 at 50 degrees C and with feeding by a pump of 54 rpm. According to the test results of wastewater from Kirka Borax treatment plants, the mean distillate fluxes were found as 13, 16 and 14 L/m(2)h at the feed temperatures of 30, 40 and 50 degrees C, respectively. The boron removal percentages were found to be 47, 64 and 48 % at 30, 40 and 50 degrees C, respectively. It was observed in the XRD spectra that the crystals in wastewater mainly consist of Na2B(OH)(4)Cl and Mg2B2O5 structures.Öğe Boron removal from wastewater by direct contact membrane distillation system using two-level factorial design(Taylor and Francis Ltd., 2023) Tan, Burcu; Yıldız, Semanur; Angin, Dilek; Bektaş, Tijen Ennil; Selengil, UgurNumerous industries use boron and its compounds in various applications. In this study, the removal of boron from an aqueous solution by direct contact membrane distillation (DCMD) system. A 23 full factorial experimental design was implemented to determine the optimum values and the degree of importance of the parameters. The experiments were performed at low and high levels of temperature, initial pH, and feed boron concentration. Design variables were evaluated in terms of individual, binary, and triple effects. At the 95% confidence level, the temperature–initial pH interaction was found as the most significant factor. The maximum boron removal efficiency can be achieved either at a low level of temperature (30 °C) and pH (4.0), or a high level of temperature (50°C) and pH (11) combinations at 20 mg/L boron concentration with desirability of 0.957.Öğe Effect of activated carbon produced from biochar on removal of 2, 4-dichlorophenoxy acetic acid from aqueous solutions(National Institute of Science Communication and Information Resources, 2021) Angin, Dilek; Güneş, Sinem; Ateş, Asude; Selengil, Uğur; Altıntığ, Esra; Tan, Burcu; Demirel, HülyaThe toxicity of pesticides and their degradation products is making these chemical substances a potential hazard by contaminating our environment. Therefore, the removal of pesticides from water is one of the major environmental concerns these days. 2,4-Dichlorophenoxy acetic acid (2,4-D) belonging to the herbicide group, which is among the numerous pesticides used today, is widely used to control weeds due to its low cost and good selectivity. In order to offer an alternative to this environmental problem, the effect of activated carbon obtained by chemical activation from pyrolysis biochar on 2,4-dichlorophenoxy acetic acid removal from aqueous solutions has been investigated. The adsorption mechanism is explained by analyzing the effect of adsorption parameters. It is determined that the equilibrium data are suitable for Langmuir isotherm model among the applied isotherm models and the monolayer adsorption capacity is 344.83 mg g-1 at 318 K. The adsorption kinetics data of 2,4-D on activated carbon is better defined by the pseudo-second-order model. Thermodynamic calculations reveal that the adsorption process is spontaneous and endothermic. The activated carbon obtained from biochar has been observed to have a high adsorption capacity compared to adsorbent materials obtained from many other raw materials for the removal of 2,4-Dichlorophenoxy acetic acid.Öğe Fabricating a new immobilization matrix based on a conjugated polymer and application as a glucose biosensor(John Wiley and Sons Inc, 2023) Tan, Burcu; Baycan, FatmaA new monomer named 4-(dihexylamino)9,12-di(thiophen-2-yl)-7H-benzo[de]benzo[4,5]imidazo[2,1-a]isoquinolin-7-one (ThBN) is synthesized and used as a potential glucose biosensor after electropolymerization of the ThBN on the graphite pencil electrode. The amount of glucose is determined according to the decrease in the amount of oxygen by using cyclic voltammetry technique. Herein, conjugated polymer of ThBN is used as a immobilization matrix. The synthesized PThBN is found to be effective enzymatic biosensor having wide linear glucose determination range between 2.975 × 10−3 and 2.087 mM with a limit of detection of 0.0304 mM and a sensitivity of 0.1326 μA/mM cm2. This potential enzymatic biosensor has been also tested in commercial samples and found to be useful to detect the glucose concentration.Öğe Glikoz tayini için konjuge polimer temelli yeni biyosensörlerin hazırlanması(Çanakkale Onsekiz Mart Üniversitesi, 2023) Tan, Burcu; Baycan, FatmaBu tez çalışmasında, özgün olarak tasarlanan, 4-(dihekzilamino)9,12- di(tiyofen-2 il)-7H-benzo[de]benzo[4,5]imidazo [2,1-a]izokunolin-7- one (ThBN) ve 4-(dihegzilamino)-9,12-bis (2,3-dihidrotiyeno[3,4-b][1,4]dioksin-5-yl)-7 H-benzo[de]benzo[4,5]imidazo[2,1-a]izoknolin-7-one (EDOTBN) monomerleri sentezlenmiş ve elektrokimyasal polimerizasyon yolu ile bu monomerlerden elde edilen konjuge polimerler, biyosensör uygulamalarında destek matrisi olarak kullanılmıştır. Konjuge polimer modifiye kalem grafit elektrotlar (KGE), altın nano partiküller (AuNP'ler) ile zenginleştirilmiş, ardından bu elektrotların yüzeyine glikoz oksidaz enziminin immobilizasyonu sağlanmıştır. Üçlü elektrot sisteminde, döngüsel voltammetri yöntemi ile, O2 tüketimine bağlı olarak enzimatik glikoz biyosensörünün performansı incelenmiştir. Enzimatik olmayan (non-enzimatik) elektokimyasal glikoz biyosensörü uygulamaları, konjuge polimer ve AuNP'ler ile zenginleştirilerek modifiye edilmiş KGE'ler ile gerçekleştirilmiştir. İdeal glikoz biyosensörleri tasarlamak amacıyla her birinin optimizasyon çalışmaları gerçekleştirilmiş, performans kriterleri değerlendirilmiştir. Literatüre katkı sağlaması hedeflenen, özgün olarak tasarlanmış konjuge polimer tabanlı biyosensörlerin doğrusal çalışma aralıkları belirlenmiş, gerçek örnekler üzerindeki glikoz tespitleri başarı ile gerçekleşmiştir.Öğe Pervaporatif Desalinasyon Için Polilaktik Asit Temelli Karma Matrisli Membranların Üretimi Ve Deniz Suyu Saflaştırılmasında Kullanımı(2022) Nigiz, Filiz Uğur; Bektaş, Tijen Ennil; Karakoca, Betül; Tan, BurcuSu, canlı yaşamı için çok önemlidir. Fakat küresel ısınma ve insan faktörlü kirlilikler nedeniyle su kaynakları kirlenmekte veya yok olmaktadır. Bu yüzden de dünyanın büyük bir kısmını kaplayan deniz sularını saflaştırarak içilebilir ve kullanılabilir su elde etmek amaçlamıştır. Bu projede ise deniz suyunu saflaştırma için çok yeni bir yöntem olan pervaporatif desalinasyon işlemi kullanılmıştır. Bu teknolojide kullanılan membranlarda temel malzeme olarak doğal kaynaklardan elde edilebilen Polilaktik asit (PLA) polimeri kullanılmıştır. Aynı zamanda MOF malzemelerinden olan MIL-140A ve MIL-140B sentezi yapılarak membranların yapısına dahil edilmiştir. Killerden olan HNT malzemesi de PLA membranların yapısında dahil edilmiştir. Bu membranların karakterizasyon testleri yapılmıştır. Pervaporasyon ile desalinasyon çalışması yapılmıştır. En yüksek akı ve tuz reddi %3 MIL 140A katkılı ve %5 HNT katkılı membranlarda elde edilmiştir. Aynı membranlar ile optimizasyon çalışması yapılmıştır ve %99 üzeri doğrulukta istatistiksel bir model oluşturulmuştur. Ardından %3 MIL-140 katkılı ve %5 HNT katkılı PLA membanlar çok ince (30 µm) olarak hazırlanmıştır. 60°C sıcaklıkta, 10 mbar basınçta ve %2 NaCl konsantrasyonda pervaporatif desalinasyon sonucunda %5 HNT katkılı membranda 13.14 kg/m2h akı ve %99,95 tuz reddi elde edilmiştir, %3 MIL-140 katkılı membranda ise 12.2 kg/m2h akı ve %99,92 tuz reddi elde edilmiştir. Bu membranlar ile deniz suyu saflaştırma işlemi yapılmış ve birçok kirleticinin içme suyu standartında ayrıldığı gözlenmiştir. Membranlar 100 saatin üzerinde kararlılık testine alınmış ne akı ne de tuz reddinde önemli düşüşler görülmemiştir.Öğe Phosphate removal by Ion exchange in batch mode(IWA Publishing, 2021) Bektaş, Tijen Ennil; Tan, Burcu; Ugurluoğlu, B. K.Water with phosphate concentrations above 2 μM may adversely affect aquatic life and human health. In this study, the parameters affecting phosphate removal from aqueous solutions by ion exchange were investigated – contact time and temperature, initial pH, initial phosphate concentration and resin dosage, and the presence of other ions. The best phosphate removal (99%) from 100 mg-P/L initial solution was observed at pH 10 and 25 °C after 3 hours of contact time. No negative phosphate removal results were obtained from phosphate solutions containing sulfate, nitrate and ammonium ions; i.e., resembling real wastewater. Desorption (with NaOH or NaCl) and recovery (with CaO) studies of phosphate sorbed by resin were also carried out, as well as thermodynamic investigations. The proportional desorbability of phosphate from the resin with NaCl was 85.6%. The recovery efficiency of phosphate was 79.4%. The sorption process was spontaneous and endothermic. The ion exchange mechanism was determined using different internal and external diffusion models. The mechanism controlling the removal of phosphate from aqueous solution is both internal and external diffusion. Application of the Langmuir and Freundlich isotherm models showed that the experimental results fit well with the Freundlich model.Öğe Zero Waste Strategies and Turkey's Zero Waste Project(Mehmet Sinan Bilgili, 2020) Tan, BurcuThe amount of waste in the world continues to increase in the framework of the population, increase in purchasing power and technological developments since the past years and this increase necessitates the need for sustainable and integrated management of waste. The disposal of waste without being used in the recycling and recovery process causes serious resource losses, both materially and energy. The zero waste movement has recently gained importance as an alternative to the dominant take-make-waste production model and as a viable approach to climate change. Zero waste is a change of perspective. It requires think again about what we traditionally regarded as garbage and instead addressing all materials as valuable resources. Zero waste takes into account the entire material management system, from extraction of natural resources to product design, production and distribution, product use and reuse, recycling, composting, energy recovery or disposal. This paper discusses a variety of zero waste strategy implementations and Turkey's Zero Waste Project.Öğe Zero waste strategies and Turkey’s zero waste project(2021) Tan, BurcuThe amount of waste in the world continues to increase in the framework of the population, increase in purchasingpower and technological developments since the past years and this increase necessitates the need for sustainableand integrated management of waste. The disposal of waste without being used in the recycling and recovery processcauses serious resource losses, both materially and energy.The \"zero waste\" movement has recently gained importance as an alternative to the dominant \"take-use-waste\"production model and as a viable approach to climate change. Zero waste is a change of perspective. It requires thinkagain about what we traditionally regarded as garbage and instead addressing all materials as valuable resources.Zero waste takes into account the entire material management system, from extraction of natural resources toproduct design, production and distribution, product use and reuse, recycling, composting, energy recovery anddisposal. This paper discusses a variety of zero waste strategy implementations and Turkey's Zero Waste Project.
