Efficient heterogeneous activation of peroxymonosulfate by modified CuFe₂O₄ for degradation of tetrabromobisphenol A

In order to enhance the catalytic activity of copper ferrite, CuFe₂O₄ doped with Ce, Sn, and Sb were prepared by sol-gel combustion method, and for the first time applied as heterogeneous catalysts to activate peroxymonosulfate (PMS) for tetrabromobisphenol-A (TBBPA) degradation in aqueous solution. Morphology, elementary composition, crystal structure, and specific surface area of the obtained catalysts were characterized. The influences of catalyst dosage, PMS concentration, initial pH, common inorganic anions, and natural organic matters (NOM) on pollutant removal were comprehensively investigated, as well as the degradation process in real wastewater. It was found that 90.1% of 15 mg/L TBBPA was removed at weak basic condition in the presence of 0.2 mM PMS and 0.075 g/L Sb-doped CuFe₂O₄, which exhibited the best catalytic activity among all the catalyst prepared. Furthermore, the active radical species responsible for TBBPA degradation were identified as sulfate radical and hydroxyl radical by using electron spin resonance (ESR) and scavenging tests. Possible catalysis mechanism was proposed based on X-ray photoelectron spectroscopy (XPS) analysis, indicating that the surface hydroxyl groups and the interactions among surface metal species, oxygen species, and PMS were critical for maintaining high catalytic activity. Based on intermediate identification, TBBPA degradation pathway was proposed. According to all the results, the Sb-doped CuFe₂O₄ with favorable catalytic ability, reusability and stability could be employed as a promising candidate for the activation of PMS to treat TBBPA-contaminated water.