Activation of hydrogen peroxide by graphite supported H₂SO₄-CeO₂ for isoniazid degradation under neutral pH

Graphite felt (GF) supported cerium oxide (CeO₂) composite with sulfation pretreatment (H₂SO₄-CeO₂/GF) was prepared by the impregnation method and employed as the catalyst to activate H₂O₂ for degradation of isoniazid (INH). The obtained samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray photoelectron spectrum (XPS). The results showed that H₂SO₄-CeO₂/GF had good properties in activating H₂O₂ for the degradation of INH. The INH removal was about 89.4% in 120 min under the following conditions: H₂O₂ 2.94 mM, H₂SO₄-CeO₂/GF 2.6 g/L, INH 10 mg/L, initial pH at 6.8 and temperature at 25 °C. The effects of some reaction parameters, including initial H₂O₂ concentration, initial INH concentration, initial pH value, the catalyst dosage and reaction temperature, on INH degradation were investigated. On the basis of mechanism study and intermediate analysis, the possible degradation pathway of INH was proposed. Besides, effective degradation of methyl orange (MO) and norfloxacin (NOF) also confirmed the high activity of H₂SO₄-CeO₂/GF in activation of H₂O₂. The H₂SO₄-CeO₂/GF was relatively stable, showing good application prospects.