Naproxen, a widely used nonsteroidal anti-inflammatory drug, has been detected in many environmental matrixes and is regarded as an emerging pollutant. Sulfate radical (SO4·-) -based advanced oxidation processes have attracted wide attention due to their high efficiency and applicability in the removal of emerging contaminants. In this study, CuFe2O4 was used as an efficient catalyst to activate peroxymonosulfate to oxidize naproxen. The results suggested that 92.3% of naproxen was degraded and 50.3% total organic carbon was removed in 60 min in the presence of 0.3 g·L-1 CuFe2O4 and 2 mM peroxymonosulfate. This degradation system showed strong adaptability in a wide pH range from 4.0 to 10.0. Free radical scavenger experiments and electron spin resonance analysis indicated that 1O2, ·OH, and SO4·- are the main active species. Finally, the potential degradation pathways of naproxen were proposed by detecting and analyzing the degradation products with ultra-high-performance liquid chromatography combined with mass spectrometry. The results of this study suggest that the CuFe2O4-activated peroxymonosulfate system is a promising technology for the removal of naproxen from natural water.
Keywords: CuFe2O4; Degradation; Electron transfer; Naproxen; Peroxymonosulfate; Singlet oxygen.