| Abstrakt: |
In this study, a statistical optimization design experiment was conducted using a face-centered central composite design-response surface methodology for the preparation of AC/TiO2-Cu ternary composite photocatalysts. The influence of preparation variables such as AC/TiO2 ratio (A = 0.1–0.5), Cu dosage (B = 0.1–0.5 g), irradiation power (C = 400–800 Watts), and irradiation time (D = 10–20 minutes) on the removal efficiency of Metronidazole (MZ) was investigated. From ANOVA analysis, the findings show 89.0% removal of MZ at the optimum preparation variables of A = 0.49, B = 0.34 g, C = 482 W, and D = 13 minutes. The regression analysis with an R2 value of 0.9907 indicates good agreement between the experimental results and the predictive values. Further studies on isotherms and kinetics were well described by the Langmuir model and pseudo second-order model, respectively. The synergetic mechanisms for the adsorption–photodegradation included three possible interactions (electrostatic attractions, π–π stacking interaction, and n–π stacking interactions) and the photogenerated electron-hole pair. From the radicals quenching test, hydroxyl radical (•OH) was found to be the most active radical for the removal of MZ. AC/TiO2-Cu ternary composite photocatalyst could be preserved up to five consecutive cycles with minor losses in removal (<9%). The results of this study show that the prepared AC/TiO2-Cu ternary composite photocatalyst substantially enhanced the adsorption–photodegradation of MZ removal in an aqueous solution under UV light irradiation. [ABSTRACT FROM AUTHOR] |
