Sürdürülebilir Kalkınma Amaçları
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- MakaleYalnız künye2025Application of SnO2@CTAB-modified zeolitic clay nanocatalyst for the efficient sonocatalytic degradation of methylene blue in wastewater: Structural characterization, catalytic activity, and mechanistic insights
Önen, Hakan; Kıranşan, Murat
This study investigates the sonocatalytic degradation of dyes in wastewater using SnO2 nanoparticles and a hybrid SnO2@CTAB-modified zeolitic clay (SnO2@M-ZLT) nanocatalyst. The catalysts were synthesized in solution medium and characterized by XRF, XRD, FT-IR, SEM, TEM, and nitrogen adsorption-desorption analyses, confirming their successful formation and suitable surface properties. The effects of critical parameters including initial dye concentration, catalyst dosage, pH, water matrix, and radical scavengers on the removal of methylene blue (MB) were systematically evaluated. Under optimal conditions (10 g L−1 catalyst, 10 mg L−1 MB, Ultrasonic power: 300 W/L, pH for MB: Natural pH), the SnO2@M-ZLT nanocatalyst achieved 97.40 % ± 1.12 % degradation within 120 min, while 95.05 % ± 1.25 % efficiency was observed at 5 g L−1 catalyst and 5 mg L−1 MB. The sonocatalytic degradation of MB over SnO₂@M-ZLT followed pseudo-first-order kinetics, with kapp values ranging from 0.004 to 0.082 mg L−1 min−1 depending on catalyst dosage, 0.012–0.083 mg L−1 min−1 with varying MB concentration, and 0.030–0.055 mg L−1 min−1 across different water matrices. The optimal degradation efficiency was obtained at a catalyst dosage of 2–2.5 g L−1, an initial MB concentration of 5–10 mg L−1, and in distilled water, confirming the strong dependence of the reaction rate on both operational and environmental factors. Reusability tests showed that SnO2@M-ZLT retained high catalytic activity after five cycles. These results highlight the strong potential of SnO2@M-ZLT as an efficient and stable nanocatalyst for sustainable wastewater treatment.
- MakaleAçık Erişim2021Investigation of the removal of sulfamethoxazole drug waste from aqueous solutions under the effect of zinc oxide/montmorillonite nanocomposite by photocatalytic ozonation process
Özyürek, Işıl Nihan; Kıranşan, Murat; Karaca, Semra
In this study, the synergistic effect of photocatalysis and ozonation processes to degrade the sulfamethoxazole (SMX), one antibiotic pharmaceutical compound, has been studied through the influence of main operational variables such as zinc oxide/montmorillonite (ZnO/MMT) dos-age, SMX initial concentration, ozone flow rate, pH and the addition of organic and inorganic scavengers. Synthesized ZnO nanoparticles were immobilized on the montmorillonite surface to prepare ZnO/MMT catalyst as a photocatalyst. The catalyst was characterized by X-ray fluo-rescence, X-ray diffraction, scanning electron microscope, high-resolution transmission electron microscope and N2 adsorption/desorption. The highest SMX degradation efficiency (80.84% for 30 min of reaction time) was obtained for the photocatalytic ozonation process compared to adsorption, single ozonation, catalytic ozonation, and photolysis. ZnO/MMT was more effective photocatalyst according to ZnO, indicating its usability as a promising photocatalyst for the removal of organic contaminants in aqueous solutions. The reduced degradation efficiency with the addition of organic and inorganic scavengers showed the important role of the photo-produced radicals and holes as well as direct ozonation in SMX degradation. A mechanism is also proposed for photocatalytic ozonation degradation by using the gas chromatography-mass spectroscopy (GC-MS) analysis method. Finally, several by-products were identified by GC-MS analysis, which allowed to depict a possible mechanism for the sulfamethoxazole degradation.