Abstract
Background: The presence of antibiotics such as metronidazole in wastewater even at low concentrations requires searching for a suitable process such as advanced oxidation process (AOP) to reduce the level of pollutants to a standard level in water. Methods: In this study, zinc oxide (ZnO) nanoparticles were synthesized by thermal method using zinc sulfate (ZnSO4 ) as a precursor, then, stabilized on stone and was used as a catalyst, in order to degrade metronidazole by photocalytic process. Effective factors on the removal efficiency of metronidazole including the initial metronidazole concentration, contact time, pH, and 0.9 gL-1 ZnO stabilized on the stone surface were investigated. Results: The X-ray diffraction (XRD) studies showed that the synthesized nanomaterials have hexagonal Wurtzite structure. Also, scanning electron microscopy (SEM) analysis revealed that the average crystalline size of the synthesized ZnO particles was in the range of 1.9-3.2 nm. The spectra represented a sharp absorption edge at 390 nm for ZnO nanoparticles corresponding to band gap of 3.168 eV. The BET-BJH specific surface area of the synthesized ZnO nanoparticles was 25.504 m2 /g. The EDS spectrum of ZnO nanoparticles showed four peaks, which were identified as Zn and O. The maximum removal efficiency was 98.36% for the synthetic solution under a specific condition (pH = 11, reaction time = 90 minutes, ZnO concentration = 0.9 gL-1, and the initial concentration of metronidazole = 10 mgL-1). The photocatalytic degradation was found to follow pseudo-first-order degradation kinetics. Conclusion: Therefore, the ZnO nanoparticles synthesized by thermal decomposition are suitable and effective photocatalytic materials for degradation of pharmaceutical contaminants.
Highlights
Antibiotics are widely introduced into water and the environment through domestic wastewater, pharmaceutical wastewater, hospital wastewater, and veterinary clinics [1,2,3]
Photocatalytic oxidation as one of the advanced oxidation processes (AOPs) due to strong decomposition characteristic of hydroxyl radicals in removal of organic pollutant has attracted much attention zinc oxide (ZnO) nanoparticles synthesized by thermal method and (Eq 1-10)
The scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis of ZnO showed the average size of 90 nm
Summary
Antibiotics are widely introduced into water and the environment through domestic wastewater, pharmaceutical wastewater, hospital wastewater, and veterinary clinics [1,2,3]. The first cycle of entry of these antibiotics into the environment is through human consumption and its entry into wastewater and there is enough evidence of its presence in wastewater [5,6] Persistent consumption of this antibiotic leads to the biological resistance of human body against diseases caused by gram-positive and gram-negative bacteria. The existence of these pharmaceuticals in wastewater is considered as emerging contaminants [7]. Methods: In this study, zinc oxide (ZnO) nanoparticles were synthesized by thermal method using zinc sulfate (ZnSO4) as a precursor, stabilized on stone and was used as a catalyst, in order to degrade metronidazole by photocalytic process. Characteristics, and photocatalytic activity of zinc oxide nanoparticles stabilized on the stone surface for degradation of metronidazole from aqueous solution.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
