Adsorption and catalytic electro-peroxone degradation of fluconazole by magnetic copper ferrite/carbon nanotubes

Copper ferrite modified carbon nanotubes (CuFe 2 O 4 /CNTs) were synthesized and employed as adsorbents/catalysts to assist electro-peroxone treatment of aqueous emerging pollutant fluconazole (FLC). Results suggest that the synthetic CuFe 2 O 4 /CNTs integrated the CNTs adsorption and ferrite magnetic abilities, showing a fast FLC removal and an excellent recyclability. The pseudo-second-order equation and the Langmuir isotherm model could well elaborate the adsorption of FLC on prepared catalysts. Compared to individual processes, electro-peroxone treatment exhibited a synergetic degradation of FLC. Approximately 89% FLC transformation was observed in the CuFe 2 O 4 /CNTs catalytic electro-peroxone process, 10% higher than that without catalysts, implying that CuFe 2 O 4 /CNTs could enhance the peroxone oxidation. Increasing of inlet gasphase ozone concentration (7.2–29.7 mg/L), catalysts dose (0.1–0.8 g/L), initial solution pH (3–11), and reaction temperature (10–30 °C) could improve the treatment efficiency, while initial FLC concentration (5–40 mg/L) and natural organic matter contents (humic acid, 0–20 mg/L) have opposite effects. The role of cathodic current density (10–60 mA/cm 2 ) was complex, 40 mA/cm 2 was observed as the optimal value. Furthermore, the degradation of FLC followed the hydroxyl radicals (HO ) oxidation mechanism. The production of HO was mainly via peroxone reactions, and the presence of CuFe 2 O 4 /CNTs could catalytic ozone and H 2 O 2 decomposition, thereby promoting HO generation. Although the magnetic CuFe 2 O 4 /CNTs had not shown obvious microelectrode characteristics, it combined adsorption and catalytic peroxone oxidation, may serve as the catalyst for electro-peroxone process.