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Öğe Batch and Column Studies for Removal of Sulphate from Real Wastewater Using Ion Exchange Resin(2019) Bektaş, Tijen Ennil; Eren, FilizIn this study, sorption potential of anion exchange resin (Lewatit Monoplus M600) to removesulphate from real wastewater was investigated. Kinetic studies were performed in batchexperiments. A comparison of kinetic models applied to the sorption of sulphate onto resin wasevaluated for the \"infinite solution volume model\" and \"unreacted core model\". Ratedeterminingstep is the liquid film control step of the unreacted core model. When pH valuesincreased above 9, more than 80% sulphate removal was observed. Column sorption-elutionexperiments were performed for the removal of the sulphate from the wastewater by resin. TheThomas and the Yoon-Nelson models were applied to experimental data to determine thecharacteristic column parameters.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 Effectiveness of fly ash in boron removal from Tuzla (Çanakkale) geothermal fluid(Yıldız Technical University, 2021) Şahin, Mehmet Oğuzhan; Bektaş, Tijen Ennil; Şanlıyüksel Yücel, DenizThe heat accumulated in the inner parts of the earth's crust is transmitted to the fluid in the geothermal aquifer by means of transportation. The geothermal fluid is transported to the surface either by wells or naturally. In this study, the geothermal fluid in Tuzla geothermal field in Çanakkale city was examined due to its high boron content (10.3 mg L-1). It was aimed to remove boron from geothermal fluid by adsorption in order to prevent possible negative effects on the environment. Fly ash was obtained from Çan thermal power plant. The specific surface area of the fly ash was 14.6 m2 g-1 and the particle size was between 1.45 and 186 µm. According to ASTM C618 standard, fly ash was classified as Class C. Fly ash was composed of anhydrite, lime, hematite, cristobalite, quartz, calcite and feldspar. Various parameters such as initial pH, adsorbent dosage, contact time, and temperature were studied experimentally for the removal of boron from the geothermal fluid. The suitability of pseudo-first-order, pseudo-second-order, and intraparticle kinetic models to experimental data was examined. The data obtained from the isotherm studies were applied to the Langmuir, Freundlich and Dubinin-Radushkevich models.Öğe Hydrothermal Synthesis of CuO Nanoparticles: Tailoring Morphology and Particle Size Variations for Enhanced Properties(2024) Akarken, Gürkan; Cengiz, Uğur; Bektaş, Tijen EnnilTransition metal oxides, particularly copper oxides, have garnered significant attention due to their intriguing photochemical, photomagnetic, photo-thermal, and photoconductive properties. Among these, CuO stands out as a p-type semiconductor having narrow bandgap energy ranges from 1.2 to 2 eV, finding versatile applications such as gas sensing, magnetic storage, solar energy conversion, photocatalysis, supercapacitors, field-emission emitters, and optical switches. Additionally, it serves as a crucial component in materials designed for lithium-ion electrodes. In this study, five different CuO nanoparticles were synthesized by simple and cost-effective hydrothermal method with various reaction temperatures and times in a teflon lined stainless steel autoclave. Copper (II) chloride dihydrate was used as copper source in this process. Various characterization techniques were conducted including X-ray powder diffraction (XRD), Raman spectroscopy, and transmitting electron microscopy (TEM). The effect of temperature and time on synthesis process was characterized and discussed. TEM images show that particle size of CuO increase with the temperature and reaction time. First reaction had the smallest particle sizes (mostly around 9-11 nm). This can be attributed to its lowest reaction temperature and shortest reaction time. For the other reactions, two of them accumulate around 19-35 nm and two around 27-45 nm range. However, the rise in the particle’s diameters is not directly proportional to temperature and time. As a result, CuO nanoparticles have been produced with simple method for the market. It can be produced in large quantities for heat exchangers, gas sensing, magnetic storage, solar energy conversion, photocatalysts, supercapacitors, etc.Öğe Investigation of the Usability of Perlite Waste for Dyestuff Removal from Aqueous Solution(2020) Selengil, Uğur; Bektaş, Tijen EnnilIn this study, unexpended perlite waste obtained from a factory producing expanded perlite was used as adsorbent. Malachite green (MG), which is a cationic dyestuff, was used as adsorbed material. The pore properties including the BET surface area, pore volume and average pore diameter were characterized. The chemical composition of the perlite was analysed by XRF. The effects of initial pH, the amount of adsorbent, contact time and initial dyestuff concentration were examined. The adsorption kinetics of dyestuff obeys the pseudo second-order kinetic model. The experimental data indicated that the adsorption isotherms are well described by the Langmuir isotherm equation. 99% dyestuff removal was obtained under optimum conditions. As a result, it was found that perlite waste was a suitable adsorbent for malachite green dyestuff.Keywords: Perlite waste, dyestuff, adsorption, isothermÖğe 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 Reduction dye in paint and construction chemicals wastewater by using microwave radiation method(Parlar Scientific Publications, 2021) Bektaş, Tijen Ennil; Angin, DilekIn this study, a novel process, microwave (MW) radiation, was used for the removal of dye from wastewater of paint and construction chemicals producing factory in Turkey. This process was the combination of MW irradiation, MW adsorbent (as catalyst), coagulant and oxidant. The activated carbon prepared from olive-waste cake by chemical activation was investigated as an MW adsorbent. Aluminum sulfate and hydrogen peroxide were used as coagulant and oxidant, respectively. The effects of radiation time, adsorbent dosage, coagulant and oxidant on the dye removal were investigated. The surface area and micropore volume of activated carbon was 1418 m(2)/g and 0.197 cm(3)/g, respectively. The presence of hydrogen peroxide showed no effect on dye removal. It has been demonstrated that the color can be effectively removed from wastewater by using activated carbon and aluminum sulphate in combination with microwave radiation. Experiments were also performed for the use of only coagulant (aluminum sulphate) and it was observed that the dye was well removed from the wastewater when the amount of coagulant was more than 0.1 g / 100 mL. Results suggest that the activated carbon obtained from olive-waste cake has potential in remediation of dye contaminated waters.Öğe REMOVAL OF ORGANIC MATTER FROM DAIRY INDUSTRY WASTEWATER USING MICROWAVE RADIATION(2020) Bektaş, Tijen Ennil; Göl, Sevgi Can; Çoker, Fazilet; Öztel, HandanThe dairy industry meets basic needs and has high production volumes. It cannot be ignored in terms of its potential for water pollution. Dairy industry wastewaters contain significant amounts of organic matter. Wastewater from the Pınar Milk Plant in Eskişehir Organized Industrial Zone was controlled by chemical oxygen demand, oil and grease, suspended solids and pH parameters. Microwave (MW) treatment involves a combination of MW irradiation, an adsorbent (as catalyst) and an oxidant. The effects of radiation power and time, and adsorbent and oxidant dosages on removal efficiency were investigated. Bentonite, limestone and pumice were used as adsorbents, with hydrogen peroxide as oxidant. The best organic matter removal (41.4%) was obtained with limestone, while 49% oil and grease removal was achieved with pumice. The best suspended solids removal (67%) was obtained with limestone.
