Photocatalytic degradation of levofloxacin using ZnO/hydroxyapatite nanocomposite: Optimization using response surface methodology

• Main Authors: Go, Adrian D., Dela Rosa, Francis M., Camacho, Drexel H., Punzalan, Eric R.
• Format: text
• Published: Animo Repository 2024
• Subjects: Hydroxyapatite; Nanocomposites (Materials); Quinolone antibacterial agents; Photocatalysis; Response surfaces (Statistics); Chemistry
• Online Access: https://animorepository.dlsu.edu.ph/faculty_research/13061
• Institution: De La Salle University

In this study, zinc oxide-hydroxyapatite (ZnO-HAp) nanocomposite was prepared via hydro- thermal method for the photodegradation of levofloxacin. The effect of different HAp loadings of the nanocomposite showed that 90 % ZnO–HAp has the highest % degradation toward levo- floxacin (88.65 %). Then, the 90 % ZnO–HAp was characterized with scanning electron mi- croscopy (SEM) and transmission electron microscopy (TEM) which a revealed rod shaped ZnO (70–150 nm) adsorbed on hydroxyapatite plates (500 nm). X-ray diffraction (XRD) and Infrared spectroscopy (FTIR-ATR) confirmed the successful synthesis of ZnO–HAp. The 90 % ZnO–HAp nanocomposite was used as a photocatalyst to degrade aqueous levofloxacin under UV irradia- tion. Optimization of the photodegradation was performed using the response surface method- ology (Box Behnken model). Analysis of variance of the model showed good predictability and goodness of fit (R2 = 99.05 %, adjusted R2 = 97.33 %, predicted R2 = 91.54 %). The optimum parameters generated were 1.32 g/L catalyst dose, 4 ppm levofloxacin, pH 7.7 and the predicted photodegradation response was 99.99 % using 90 % ZnO–HAp. Subsequent experimental veri- fication yielded an actual % degradation of 91.69 % under the obtained optimized conditions. Additionally, the 90 % ZnO–HAp phtocatalyst exhibited good recyclability over four cycles.