Photocatalytic degradation of pharmaceutical contaminants in wastewater assisted by ecofriendly synthesized ZnO nanoparticles

Abstract

In this study, the photocatalytic degradation of cefotaxime (CFM), ciprofloxacin (CIP), and vancomycin (VAN) in aqueous solution was investigated using the green nanophotocatalyst ZnONPs, synthesized from banana peels. A predictive mathematical model based on response surface methodology was developed to explore this degradation process. Three independent variables were investigated: the initial concentration of the antibiotic, the dose of ZnONPs nanocatalyst, and the irradiation time. The response studied was the percentage degradation of the antibiotic. A Box Behnken design was adopted, revealing an optimal level of degradation for CFM, CIP, and VAN, reaching 40.41%, 61.51%, and 53.22%, respectively. This optimum was observed at initial antibiotic concentrations of 10.78 mg/L, 29.99 mg/L, and 29,92 mg/L, a dose of ZnONPs nanocatalyst of 0.78 g/L, 0.70 g/L, and 0.77 g/L, and irradiation times of 89.46 minutes, 89.99 minutes, and 60 minutes, respectively.