Environmental Engineering / Çevre Mühendisliği

Permanent URI for this collectionhttps://hdl.handle.net/11147/4321

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  • Article
    Citation - WoS: 40
    Citation - Scopus: 47
    Boron in Geothermal Energy: Sources, Environmental Impacts, and Management in Geothermal Fluid
    (Elsevier, 2022) Mott, A.; Baba, Alper; Hadi Mosleh, Mojgan; Ökten, Hatice Eser; Babaei, Masoud; Gören, Ayşegül Yağmur; Feng, C.; Recepoğlu, Yaşar Kemal; Uzelli, Taygun; Uytun, Hüseyin; Morata, Diego; Yüksel Özşen, Aslı
    The problem of hazardous chemicals in geothermal fluid is a critical environmental concern in geothermal energy developments. Boron is among the hazardous contaminants reported to be present at high concentrations in geothermal fluids in various countries. Poor management and inadequate treatment of geothermal fluids can release excessive boron to the environment that has toxic effects on plants, humans, and animals. Despite the importance of boron management in geothermal fluid, limited and fragmented resources exist that provide a comprehensive understanding of its sources, transport and fate, and the treatment strategies in geothermal energy context. This paper presents the first critical review from a systematic and comprehensive review on different aspects of boron in geothermal fluid including its generation, sources, toxicity, ranges and the management approaches and treatment technologies. Our research highlights the origin of boron in geothermal water to be mainly from historical water-rock interactions and magmatic intrusion. Excessive concentrations of boron in geothermal fluids have been reported (over 500 mg/L in some case studies). Our review indicated that possible boron contamination in geothermal sites are mostly due to flawed construction of production/re-injection wells and uncontrolled discharge of geothermal water to surface water. The dominancy of non-ionic H3BO3 species makes the selection of the suitable treatment method for geothermal waters limited. Combining boron selective resins and membrane technologies, hybrid systems have provided effluents suitable for irrigation. However, their high energy consumption and course structure of boron selective resins encourage further research to develop cost-effective and environmentally friendly alternatives.
  • Article
    Citation - WoS: 42
    Citation - Scopus: 44
    Boron Carbon Nitride Nanosheets in Water and Wastewater Treatment: a Critical Review
    (Elsevier, 2022) Recepoğlu, Yaşar Kemal; Gören, Ayşegül Yağmur; Vatanpour, Vahid; Yoon, Yeojoon; Khataee, Alireza
    The availability and accessibility of clean and secure water supplies are pressing technological and scientific issues worldwide. As a result of global water constraints, wastewater treatment and reuse are being evaluated as feasible alternatives to fresh water for agricultural irrigation and domestic and industrial purposes. Boron carbon nitride (BCN) nanosheets have been studied intensively in the last decade in batteries, biosensors, and capacitors, and for use as catalysts, and they have recently been used in wastewater treatment. BCN materials, along with their synthesis processes, characteristics, and application areas in water and wastewater treatment, are discussed thoroughly in this paper. Additionally, synthesis processes for ternary BCN compounds, including chemical vapor deposition, ion beam-aided deposition, magnetron sputtering, and pulsed laser deposition, are described. BCN materials have also been explored because of their flexible electrical features, excellent mechanical strength, outstanding unreactivity, and significant stability, which make them appropriate for a range of severe environment applications. Thus, the use of BCN materials as photocatalysts and adsorbents and in electrochemical reduction and capacitive deionization are also discussed thoroughly. The highest ammonia production of 172,226.5 μg/h.mg.cat and faradic efficiency of 95.3% have been obtained using the BCN@Cu/CNT catalyst, whereas the ammonia production and FE values for metal-free BCN are 7.75 μg/h.mg.cat and 13.8%. Moreover, the maximum attained adsorption capacities of BCN nanosheets for Pb2+ and Hg2+ are 210 and 625 mg/g, respectively. Overall, this review indicates that essential work on BCN nanosheets is still needed. Future research should focus on the development of BCN nanostructures to encourage multidisciplinary research.
  • Article
    Methylene Blue Removal of Fixed-Bed Column Reactor With Pumice and Nzvi-Pumice: Experimental and Modeling Study
    (Süleyman Demirel Üniversitesi, 2019) Genişoğlu, Mesut; Gören, Ayşegül Yağmur; Balcı, Esin; Recepoğlu, Yaşar Kemal; Ökten, Hatice Eser
    Nano zero-valent iron (nZVI) emerges as a low cost and eco-friendly adsorbent to treat textile wastewater, which is rich in dye content. However nZVI particles can easily agglomerate in aqueous environment due to electrostatic interaction, decreasing their treatment efficiency. Therefore pumice, a low-cost and naturally found porous material with lower specific surface area (2m2/gr), can be used as support material to reduce agglomeration of nZVI. Treatment efficiencies of pumice/nZVI packing (10:0 and 9:1 (w/w)) in column reactor for specified initial methylene blue concentrations (25, 50, 75 and 100 mg/L) were investigated in this study. Adsorption capacities of the adsorbents were calculated as 2.8 and 4.2 mg/g-adsorbent, respectively at 100 mg/L initial methylene blue concentration. Mixed bed column performed significantly better than its pumice-only counterpart for low initial concentrations. Thomas adsorption model was applied to experimental results with a moderate to high predictive power.