Heterogeneous Sono-Fenton like catalytic degradation of metronidazole by Fe3O4@HZSM-5 magnetite nanocomposite

Ghazal Yazdanpanah; Mohammad Reza Heidari; Najmeh Amirmahani; Alireza Nasiri

doi:10.1016/j.heliyon.2023.e16461

Heterogeneous Sono-Fenton like catalytic degradation of metronidazole by Fe₃O₄@HZSM-5 magnetite nanocomposite

Heliyon. 2023 May 26;9(6):e16461. doi: 10.1016/j.heliyon.2023.e16461. eCollection 2023 Jun.

Authors

Ghazal Yazdanpanah¹, Mohammad Reza Heidari², Najmeh Amirmahani¹, Alireza Nasiri¹

Affiliations

¹ Environmental Health Engineering Research Center, Kerman University of Medical Sciences, Kerman, Iran.
² Environmental Health Engineering, Department of Environmental Health, School of Public Health, Bam University of Medical Sciences, Bam, Iran.

Abstract

In this research, Fe₃O₄@HZSM-5 magnetic nanocomposite was synthesized via a coprecipitation method for metronidazole (MNZ) degradation from aqueous solutions under ultrasonic irradiation which showed superb sonocatalytic activity. The synthesized magnetite nanocomposite was characterized by using field-emission scanning electron microscope-energy dispersive X-ray Spectroscopy, (FESEM-EDS), Line Scan, Dot Mapping, X-ray diffraction (XRD), vibrating sample magnetometer (VSM), and Brunauer-Emmett-Teller (BET). To investigate the sonocatalytic activity of the Fe₃O₄@HZSM-5 magnetite nanocomposite, the sonocatalytic removal conditions were optimized by evaluating the influences of operating parameters like the dosage of catalyst, reaction time, pH, the concentration of H₂O₂, MNZ concentration, and pH on the MNZ removal. The MNZ maximum removal efficiency and TOC at reaction time 40 min, catalyst dose 0.4 g/L, H₂O₂ concentration 1 mM, MNZ initial concentration 25 mg/L, and pH 7 were achieved at 98% and 81%, respectively. Additionally, the MNZ removal efficiency in the real wastewater sample under optimal conditions was obtained at 83%. The achieved results showed that using Langmuir-Hinshelwood kinetic model K_L-H = 0.40 L mg^-1, K_C = 1.38 mg/L min) can describe the kinetic removal of the process. The radical scavenger tests indicated that the major reactive oxygen species were formed by hydroxyl radicals in the Sono-Fenton-like process. Evaluation of the nanocomposite reusability showed an 85% reduction in the MNZ removal efficiency after seven cycles. Based on the results, it can be concluded that Fe₃O₄@HZSM-5 were synthesized as magnetic heterogeneous nano-catalysts to effectively degrade MNZ, and the observed stability and recyclability demonstrated that Fe₃O₄@HZSM-5 was promising for the treatment of wastewater contaminated with antibiotics.

Keywords: Heterogeneous catalyst; Metronidazole; Sono-Fenton like; Wastewater.