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    Cerium-Doped CuFe-Layered Catalyst for the Enhanced Oxidation of o-Xylene and N,N-Dimethylacetamide: Insights into the Effects of Temperature and Space Velocity
    (Amer Chemical Soc, 2023) Ocal, Zehra Betul; Keyikoglu, Ramazan; Karagunduz, Ahmet; Yoon, Yeojoon; Khataee, Alireza
    Volatile organic compounds (VOCs) are among the most potential pollutant groups that cause air quality degradation because of their toxic effects on human health. Although catalytic oxidation is an effective method for VOC removal, further studies are required to develop more efficient and affordable catalysts. In this study, cerium (Ce) was doped into a CuFe-layered material (Ce-CuFe) to improve the catalytic oxidation efficiencies of N,N-dimethylacetamide (DMAC) and o-xylene. The synthesized catalyst was characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), energy-dispersive X-ray spectroscopy (EDS), Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) analysis. XRD analysis confirmed the successful doping of Ce atoms into the CuFe-layered structure, while in the SEM and TEM images the catalyst appeared as uniformly distributed two-dimensional plate-like particles. The catalytic oxidation performance of the Ce-CuFe was investigated at six temperatures between 200 and 450 degrees C and three space velocities in the range of 31000-155000 mLh(-1)g(-1) for the oxidation of DMAC and o-xylene, which functioned as polar and nonpolar solvents, respectively. At 200 degrees C, the Ce-CuFe catalyst performed 50% greater when oxidizing o-xylene while exhibiting a DMAC oxidation efficiency that was 42% greater than that achieved using undoped CuFe. The Ce-CuFe could remove DMAC and o-xylene with an efficiency higher than 95% at 450 degrees C. Furthermore, Ce-doped CuFe exhibited high resistance against moisture and outstanding reusability performance with only a 5.6% efficiency loss after nine reuse cycles. Overall, the incorporation of Ce into a CuFe-layered material is a promising strategy for the oxidation of various VOCs.
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    Öğe
    Degradation and ecotoxicity of favipiravir and oseltamivir in the presence of microplastics during ozonation and catalytic ozonation of synthetic municipal wastewater effluents
    (Wiley, 2025) Dogruel, Serdar; Chavoshi, Nasim; Bilgin-Saritas, Nilay; Khataee, Alireza; Topuz, Emel; Pehlivanoglu, Elif
    BackgroundFavipiravir (FAV) and oseltamivir (OSE) are antiviral agents developed against influenza and they were repurposed against SARS-CoV-2 during the COVID-19 pandemic. This study evaluated the potential of ozonation and catalytic ozonation as tertiary treatment approaches for removing FAV and OSE from municipal wastewaters, both in the presence and absence of microplastics (MPs), while comparing the ecotoxicity of untreated and treated secondary effluents to predict the ecotoxicological effects of these technologies during municipal wastewater treatment.ResultsAt an initial antiviral concentration of 50 mu g L-1, ozonation at pH 7 with a specific ozone dose of 0.6 mg O3 (mg DOC)-1 yielded FAV and OSE removals of 84 and 64%, respectively, while the presence of catalyst or MPs decreased the degradation rate by 30-40%. Raising the pH to 10 had minimal impact on FAV abatement, but improved OSE reduction by 21%. Acute toxicity tests using Vibrio fischeri demonstrated that simultaneous ozonation of the analytes led to the accumulation of transformation products (TPs) of FAV and OSE, with their combined effect almost equal to that of the original compounds. Reproduction toxicity tests indicated that TPs of antiviral drugs generated during ozonation were less toxic to Enchytraeus crypticus than the parent chemicals.ConclusionOzonation proved to be a viable option for upgrading existing wastewater treatment facilities, serving as a complementary treatment to minimize the release of antivirals from municipal secondary effluents and reduce their inhibitory effect on earthworm reproduction, thereby enhancing the reuse potential of treated wastewater for irrigation. (c) 2025 The Author(s). Journal of Chemical Technology and Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry (SCI).
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    Öğe
    Sustainable treatment of boron industry wastewater with precipitation-adsorption hybrid process and recovery of boron species
    (Elsevier, 2024) Ocal, Zehra Betul; Oncel, Mehmet Salim; Keskinler, Bulent; Khataee, Alireza; Karagunduz, Ahmet
    Boron removal from wastewater has been investigated by using various processes, including ion exchange resins, membrane processes and adsorption. Each method has various advantages and disadvantages, but most produce excessive waste in addition to high operational costs. Therefore, more sustainable methods are required for wastewater containing high concentrations of boron. In this study, a sustainable treatment process was developed for wastewater containing high concentrations of boron. This study investigated the removal of boron from wastewater by Al(OH)(3) sorption. The reuse of adsorbent (Al(OH)(3)) and the potential recovery of boric acid was the main goal of the study. It was observed that although lower concentrations of boron were obtained at pH 10.5 (980 mg/L and 635 mg/L at pH of 9.0 and 10.5, respectively), the amount of sorbed boron at pH 9 was substantially higher (94.7 mg B/g Al(OH)(3) and 27.8 mg B/g Al(OH)(3) at pH of 9.0 and 10.5, respectively). This was attributed to the higher initial boron concentrations and the formation of boric acid and polyborate complexes at pH 9.0. Results showed that polyborate species sorption was an outer sphere complex formation, which led to the desorption of boron as pH lowered. Adsorbed boron species to Al(OH)(3) could effectively be desorbed at low pH values (pH<5.0); which allows Al(OH)(3) to be used in successive adsorption studies. Approximately 55% of boron recovery from pretreated wastewater was possible with the effective reuse of adsorbent. A net profit of 2.85 $/m(3) could be obtained based on the amounts of chemical consumptions and boron recovery.