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  • Küçük Resim
    Öğe
    Sonocatalytic degradation of fluoroquinolone compounds of levofloxacin using titanium and zirconium oxides nanostructures supported on paper sludge/wheat husk-derived biochar
    (Korean Society of Industrial Engineering Chemistry, 2022) Motlagh, Parisa Yekan; Soltani, Reza Darvishi Cheshmeh; Pesaran, Zoha; Akay, Sema; Kayan, Berkant; Yoon, Yeojoon; Khataee, Alireza
    The present study aimed at treating a water medium containing pharmaceutical compounds such as levofloxacin (LEV). For this purpose, ultrasound (US)-based degradation of LEV was catalyzed by TiO2 and ZrO2 nano-catalysts supported on biochar (BC). BC was obtained from a precursor composite of paper sludge and wheat husk. The application of BC-ZrO2 led to a degradation efficiency of 54.65% within 60 min. When BC-TiO2 was used, a lower degradation efficiency of 49.62% was obtained at the same reaction time. However, increasing the time to 120 min improved the sonocatalytic degradation of LEV by BC-TiO2 (72.88%) compared to that of BC-ZrO2 (66.42%). In the presence of H2O2 and S2O82?, the LEV degradation efficiency of US/BC-TiO2 increased from 72.88% to 87.98% and 94.03%, respectively, and for the US/BC-ZrO2 process, it increased from 66.42% to 76.79% and 90.14%, respectively. The addition of isopropanol caused the most suppressive effect on the sonocatalytic degradation of LEV for both US/BC-TiO2 (decreasing from 72.88% to 13.99%) and US/BC-ZrO2 (decreasing from 66.42% to 16.43%) processes. The reusability test results showed an approximately 20% reduction in the sono-reactor performance within three consecutive experimental runs with no substantial change in the functional groups of the as-prepared sonocatalyst. Intermediates of LEV decomposed by the two sonocatalytic processes were also identified.
  • Küçük Resim
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    Ultrasonic-assisted photocatalytic degradation of various organic contaminants using ZnO supported on a natural polymer of sporopollenin
    (Elsevier B.V., 2023) Yekan Motlagh, Parisa; Vahid, Behrouz; Akay, Sema; Kayan, Berkant; Yoon, Yeojoon; Khataee, Alireza
    Water resource pollution by organic contaminants is an environmental issue of increasing concern. Here, sporopollenin/zinc oxide (SP/ZnO) was used as an environmentally friendly and durable catalyst for sonophotocatalytic treatment of three organic compounds: direct blue 25 (DB 25), levofloxacin (LEV), and dimethylphtalate (DMPh). The resulting catalyst had a 2.65 eV bandgap value and 9.81 m2/g surface area. The crystalline structure and functional groups of SP/ZnO were confirmed by X-ray diffraction (XRD) and Fourier transforms infrared spectroscopy (FTIR) analyses. After 120 min of the sonophotocatalysis, the degradation efficiencies of DB 25, LEV, and DMPh by SP/ZnO were 86.41, 75.88, and 62.54%, respectively, which were higher than that of the other investigated processes. The role of reactive oxygen species were investigated using various scavengers, enhancers, photoluminescence, and o-phenylenediamine. Owing to its stability, the catalyst exhibited good reusability after four consecutive cycles. In addition, the high integrity of the catalyst was confirmed by scanning electron microscopy (SEM), XRD, and FTIR analyses. After four consecutive examinations, the leaching of zinc in the aqueous phase was < 3 mg/L. Moreover, gas chromatography-mass spectrometry (GC–MS) analyses indicated that the contaminants were initially converted into cyclic compounds and then into aliphatic compounds, including carboxylic acids and animated products. Thus, this study synthesized an environmentally friendly and reusable SP/ZnO composite for the degradation of various organic pollutants using a sonophotocatalytic process.