Fe3O4–CuO@Lignite activated coke activated persulfate advanced treatment of phenolic wastewater from coal chemical industry

In this study, lignite activated coke (LAC) was used as the carrier for the first time, Fe 3 O 4 –CuO composite metal oxide was used as the main active material, and the nano-scale magnetic supported composite metal oxide Fe 3 O 4 –CuO@LAC catalyst was synthesized for the first time, which can effectively activate the active oxygen in peroxodisulfate (PS). XRD, FTIR , BET, SEM , XPS and other analysis results showed that there was particulate matter with spherical structure on the surface of the active coke, and its diffraction peaks matched well with the characteristic peaks of Fe 3 O 4 and CuO, and it was a mesoporous structure with a specific surface area of 619.090 m 2 g −1 . By optimizing the experimental conditions, the results showed that more than 92% of hydroquinone can be removed under the conditions of hydroquinone concentration of 50 mg/L, pH = 5, adding 0.1 g/L catalyst and 3 mmol/L PS. EPR and quenching experiments proved that there were four reactive oxygen species in the reaction system ·OH, SO 4 − ·, O 2 − · and 1 O 2 . According to the degradation products of hydroquinone detected by LC-MS, the possible degradation path was deduced which laid a foundation for solving the problem of difficult treatment of phenol-containing wastewater in coal chemical industry. • LAC used to synthesize a catalyst for activating persulfate for the first time. • LAC is a by-product in coal chemical industry. Waste is used to treat waste. • The degradation rate of hydroquinone can reach over 92%. • The Fe 3 O 4 –CuO@LAC catalyst still has good stability after 4 cycles.