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Öğe Removal of Cr(VI) from Aqueous Solutions Using Thermal Power Plant Gas Purification Waste (Reduction and Adsorption of Hexavalent Chromium), Interpretation of Mechanism: Disposal of Waste and Residues(Springer Int Publ Ag, 2025) Saglam, Semanur; Eren, Sena; Turk, Feride N.; Arslanoglu, HasanFlue Gas Desulfurization System (FGD) is a treatment system that has been made mandatory in thermal power plants for sulfur retention in recent years. FGD systems have been made mandatory in coal-based energy generating systems, especially in order to reduce the increasing greenhouse gas effect and to prevent the release of coal-derived sulfur oxides into nature. The hot waste steam from the boiler is sent to the FGD columns and milk of lime is fed to absorb the sulfur oxides. After treatment, thermal power plant gas treatment waste (PW) with a high content of gypsum is produced. In this study, the removal of chromium from aqueous solutions by PW was investigated. Cr(VI) adsorption studies were optimized using Taguchi analysis. In this context, L25 Taguchi orthogonal array was applied using 5 factors and 5 levels to optimize experimental parameters such as pH, dosage, contact time, concentration, temperature which affect adsorption. Elemental analysis, BET, TGA, XRD, XRD, FT-IR analyses were applied to determine the physicochemical properties of the waste. Adsorption isotherms and kinetics were also studied to investigate the Cr(VI) removal and mechanism of the material. The optimum experimental conditions were determined as initial pH 2.13, concentration 20 mg/L, dosage 22.5 g/L, time 12 h and temperature 32.5 degrees C by Taguchi method. Under these conditions, 100% Cr(VI) removal was successfully achieved. The results obtained show that PW is successful in Cr(VI) removal. The utilization of FGD waste is very important in terms of sustainability and environment. An alternative method has been presented as a solution to the increasing depletion of global water resources and the increasing need for land for PW storage.Öğe Salix babylonica (Salicaceae) atıklarından iyon değiştirici aktif karbonun elde edilmesi ve atık suların arıtımında kullanılması: hedef sıfır atık(Çanakkale Onsekiz Mart Üniversitesi, 2025) Eren, Sena; Arslanoğlu, Hasan; Türk, Feride NaimeTarımsal atıklar, sürdürülebilir ve çevre dostu olmalarının yanı sıra atık yönetimi açısından da büyük bir potansiyele sahiptir. Bu tez çalışmasında, Salix babylonica atıkları doğal iyon değiştirici olarak kullanılmış ve aktif karbon üretiminde karbon kaynağı olarak kullanılarak katma değerli ürünlere dönüştürülmüştür. Lignoselülozik biyokütle kaynağı olan bu atığın hücre duvarlarının amin grupları, karboksil grupları ve fenolik OH grupları içerdiği bilgisi, doğal katyon değiştirici olarak kullanılabileceği fikrini ortaya çıkarmıştır. Aynı zamanda karbon açısından da zengin olan biyokütle kaynakları aktif karbon sentezi için potansiyel hammaddelerdir. Bu doğrultuda atıklardan kimyasal aktifleştirici ajan ZnCl2 kullanılarak aktif karbon sentezlenmiştir. Literatür araştırması sonucunda, daha yüksek gözenek ve yüzey alanı elde etmek için 800 °C'de yavaş piroliz işlemi tercih edilmiş ve 984,433 m/g yüzey alanına sahip aktif karbon başarıyla sentezlenmiştir. Salix babylonica atıkları ve aktif karbon kullanılarak adsorpsiyon ve iyon değişimi yöntemleriyle atık sulardan metilen mavisi (MB) uzaklaştırılmıştır. Optimum deneysel koşulların belirlenmesi adına Taguchi L25 ortagonal dizisi uygunlanmıştır. Adsorpsiyon sürecini etkileyen parametrelerin (pH 2-11, konsantrasyon 20-100 mg/L, dozaj 1-20 g/L, sıcaklık 30-70 oC, süre 15-180 dk) etkileri, oluşturulan grafikler ile desteklenerek incelenmiştir. Atıkları ve sentezlenen aktif karbonu karakterize etmek için Fourier Transform İnfrared Spektroskopisi (FTIR), Termogravimetrik Analiz (TGA), Taramalı Elektron Mikroskobu (SEM-EDX) ve BET analizleri kullanılmıştır. Farklı koşullar altında gerçekleştirilen deneylerin sonucunda optimum şartlarda doğal katyon değiştirici ile %98,875, sentezlenmiş aktif karbon ile %100 oranında metilen mavisi giderimine ulaşılmıştır. Yürütülen çalışmalar sonucunda atık sulardan metilen mavisi giderimi için Salix babylonica atıklarının ve sentezlenen aktif karbonun uygun maliyetli, verimli, çevre dostu ve gelecek vaad eden malzemeler olduğu belirlenmiştir.Öğe Synthesis of zeolite from industrial wastes: a review on characterization and heavy metal and dye removal(Springer, 2024) Eren, Sena; Türk, Feride N.; Arslanoğlu, HasanIncreasing world population, urbanization, and industrialization have led to an increase in demand in production and consumption, resulting in an increase in industrial solid wastes and pollutant levels in water. These two main consequences have become global problems. The high Si and Al content of solid wastes suggests that they can be used as raw materials for the synthesis of zeolites. In this context, when the literature studies conducted to obtain synthetic zeolites are evaluated, it is seen that hydrothermal synthesis method is generally used. In order to improve the performance of the hydrothermal synthesis method in terms of energy cost, synthesis time, and even product quality, additional methods such as alkaline fusion, ultrasonic effect, and microwave support have been developed. The zeolites synthesized by different techniques exhibit superior properties such as high surface area and well-defined pore sizes, thermal stability, high cation exchange capacity, high regeneration ability, and catalytic activity. Due to these specific properties, zeolites are recognized as one of the most effective methods for the removal of pollutants. The toxic properties of heavy metals and dyes in water and their carcinogenic effects in long-term exposure pose a serious risk to living organisms. Therefore, they should be treated at specified levels before discharge to the environment. In this review study, processes including different methods developed for the production of zeolites from industrial solid wastes were evaluated. Studies using synthetic zeolites for the removal of high levels of health and environmental risks such as heavy metals and dyes are reviewed. In addition, EPMA, SEM, EDX, FTIR, BET, AFM, and 29Si and 27Al NMR techniques, which are characterization methods of synthetic zeolites, are presented and the cation exchange capacity, thermodynamics of adsorption, effect of temperature, and pH are investigated. It is expected that energy consumption can be reduced by large-scale applications of alternative techniques developed for zeolite synthesis and their introduction into the industry. It is envisaged that zeolites synthesized by utilizing wastes will be effective in obtaining a green technology. The use of synthesized zeolites in a wide variety of applications, especially in environmental problems, holds great promise. Graphical Abstract: (Figure presented.) © The Author(s) 2024.Öğe Valorization of waste biomass derived activated carbon @expanded graphite for intensification of thermal characteristics of RT24 phase change material through shape-stabilization(Elsevier, 2025) Gowthami, D.; Sharma, R. K.; Kar, Turgay; Sarı, Ahmet; Arslanoğlu, Hasan; Eren, Sena; Gençel, OsmanThe basic philosophy of this work is to create cleaner energy alternative materials for solar thermal energy storage applications. This experimental evaluation focuses on elevating the thermal characteristics of Rubitherm paraffin (RT24) by incorporating a hybrid matrix for shape stabilization. The hybrid matrix was fabricated by infusing expanded graphite (EG) (5 wt% and 10 wt%) into carbonized sugar beet pulp and vinasse wastes (BAC). The shape-stabilization of RT24 was carried out in vacuum to achieve uniform dissipation. The synthesized hybrid supporting matrices were adequately porous with highest BET surface area of 411.25 m2/g after adding EG(5 wt%) to BAC. According to TGA analysis BAC/RT24, BAC@5%EG/RT24(45 %) and BAC@10%EG/RT24 (60 %) were highly resistant to heat with corresponding mass loss of 39.4 %, 44.7 % and 59.8 % at around 280 degrees C. In accordance with XRD and FTIR analysis PCM composites have not displayed structural or chemical transformation due to the presence of EG or BAC. The melting and solidifying latent heat values of BAC@10% EG/RT24(60 %) were measured as 132.15 J/g and 129.42 J/g respectively. Also, BAC/RT24, BAC@5%EG/RT24 (45 %) and BAC@10%EG/RT24(60 %) have revealed high thermal reliability after performing 1000 thermal cycles with a variation of about 3 % in melting latent heat, thus signifying their adaptability into latent heat storage (LHS) systems. Thermal conductivity of the shape-stable BAC/RT24 composite was increased by 300 % compared to pure RT24 PCM as a result of adding 10 wt% EG to the composite. Especially BAC@10%EG/RT24 (60 %) composite can be utilized as cleaner energy alternative material for building solar thermal implementation because it had relatively higher LHS capacity and thermal conductivity value.
