Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleAçık Erişim2023Scopus SJRQ3Comparison of the removal efficiencies of Basic red 46 from aqueous solutiousing Aşkale lignite with and without ultrasound assisted processes
Karaca, Canan; Karaca, Melike; Kıranşan, Murat; Karaca, Semra; Açışlı, Özkan; Gürses, Ahmet
This study compared the removal efficiencies of Basic red 46 from aqueous solutions with and without ultrasound-assisted processes using lignite as a low-cost adsorbent. The effects of various experimental parameters such as contact time, adsorbent dosage, initial solution, pH, initial dye concentration and temperature on the dye removal efficiency were investigated. The experimental results were modelled by the kinetic and isotherm models. Both of processes fitted well to pseudo-second-order kinetics and the Langmuir model with highest correlation coefficients for all of three temperatures. The results showed that the influence parameters have a different effect on the removal efficiency in the presence and absence of ultrasonic irradiation. When the results obtained for both processes are compared, it is seen that the removal efficiency obtained with the ultrasound assisted process is much higher than that obtained with non-ultrasound assisted process at high dye concentrations. The removal efficiency of ultrasound-assisted and unassisted processes was found to be 81.5% and 54.6%, respectively, at 80 mg/L dye concentration and 60 min. Thermodynamic parameters showed that the adsorption process was spontaneous and exothermic. The enthalpy and entropy changes for the ultrasound-assisted process were –9.35 kJ/mol and –0.03 kJ/K·mol, respectively.
AtıfScopus6WoS5OpenAlex9İncele - MakaleAçık Erişim2021Scopus SJRQ3Investigation 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.
AtıfScopus9WoS7OpenAlex10İncele