Removal of levofloxacin by persulfate activated by nZVI/Co/N-CNT

Abstract

A composite catalyst nZVI/Co/N-CNT was prepared by loading nano-zero-valent iron-cobalt bimetals on porous materials (N-CNT) by a liquid-phase reduction method. Transmission electron microscopy (TEM), X-ray diffraction (XRD) and the X-ray electron spectroscopy (XPS) characterization method were used to characterize and analyze the structure of the prepared samples. The effects of different factors on the removal of levofloxacin (LOF) by the nZVI/Co/N-CNT activated persulfate (PMS) system were compared. The results show that the removal rate of LOF can reach 98.14% when the LOF concentration is 20 mg/L, the iron-cobalt molar ratio is 5:1, the dosage of nZVI/Co/N-CNT is 0.3 g·L−1, and the dosage of PMS is 0.2 g·L−1 and pH = 7. Free radical quenching experiments showed that SO4−· and ·OH coexisted during the reaction, and ·OH was the main active species, and the possible removal mechanism of LOF was speculated. HIGHLIGHTS For the first time, nitrogen-doped carbon nanotubes loaded with Fe-Co nanoparticles were used to activate PMS to degrade antibiotic wastewater.; The agglomerative property of nano-metal was improved by loading nano-Fe – Co onto porous carbon nanotubes.; The composite material can effectively activate PMS, which provides a good prospect for the treatment of wastewater by environmental functional materials.;

Keywords

• levofloxacin
• nzvi/co/n-cnt
• persulfate
• reaction mechanism