纳米Fe3O4/H2O2降解诺氟沙星

采用纳米Fe3O4催化H2O2氧化降解水环境中的诺氟沙星.考察了溶液酸度、温度、催化剂和H2O2浓度对诺氟沙星降解的影响,对比不同底物在Fe3O4/H2O2体系中的降解情况,并进一步探讨了其反应机制.结果表明,溶液酸度显著影响诺氟沙星的降解率,在酸性条件下（pH=3.5）诺氟沙星的降解效率最高.诺氟沙星的降解率随纳米F...

Degradation of Norfloxacin by Nano-Fe3O4/H2O2

The degradation of norfloxacin in aquatic environment was studied in the presence of Fe₃O₄ nanoparticles and H₂O₂.The effects of solution pH, temperature, dose of catalysts and concentration of H₂O₂ on norfloxacin degradation were surveyed. The degradation behaviors of different substrates by nano-Fe₃O₄/H₂O₂ were investigated and the reaction mechanism of norfloxacin was discussed. The results showed that the reaction was strongly pH-dependent and favored in acidic solution (pH=3.5). The removal efficiency of norfloxacin was enhanced with the increase of temperature, catalysts dosage and H₂O₂ concentration. The degradation efficiency of norfloxacin by nano-Fe₃O₄/H₂O₂ was significantly higher than those of sulfathiazole, phenolic and aniline compounds. In the presence of 4.4 mmol·L^-1 of H₂O₂, 0.80 g·L^-1 of Fe₃O₄ and T=303 K, norfloxacin was degraded completely in 5 min. The F element in norfloxacin molecule existed totally as F^- in solution within 5 min, and the removal efficiency of total organic carbon was 57% in 1 h. In the ESR spectrum of nano-Fe₃O₄/H₂O₂ system, the characteristic peaks of BMPO-·OH adduct was detected, however, the intensity of the peaks was reduced to 5% with the addition of tert-butanol, a strong ·OH scavenger, and the degradation efficiency of norfloxacin was correspondingly decreased to 10% in 1 h. These results indicated that ·OH played an important role on norfloxacin degradation, and the reaction proceeded based on a heterogeneous Fenton-like system.