Enhanced sonocatalytic degradation of Metronidazole from aqueous solutions using nano-sized magnetite

Background and Aim: In recent years, drugs have been identified as emerging contaminants and threatening the environment and human health. Long-term exposure to these compounds can cause changes in microbial ecology, the development of antibiotic resistance, provoking toxic effects on aquatic species and also have on human health through the food chain. Therefore, the assessment of removal of metronidazole from aqueous solutions is important regarding to reduce the negative impacts on the environment and human health. Materials and Methods: In this study, first, the magnetite was synthesized. The effective operating parameters (solution pH, magnetite nanoparticles( MNPs) dosage, ultrasonic power and initial antibiotic concentration) were studied. Taguchi method to determine the optimum conditions were used. Results: Complete removal of Metronidazole was obtained at 0.8 g/L MPNs, pH=5, 300W/L ultrasonic power, 25 min reaction time and Initial concentration 0.25 mg/l. Moreover, the results of kinetic studies showed that ultrasonic/MNPs was best fitted with a first-order kinetic model. According to the total organic carbon (TOC) analysis, around 78% mineralization was observed after 180 min for initial Metronidazole concentration of 5 mg/L. Conclusion: The results of this study showed that the ultrasound/MNPs are considered as a highly efficient for degradation of antibiotic in water and wastewater treatment systems.

Keywords:

degradation , nano-sized magnetite , metronidazole