Sulfate radicals induced degradation of tetrabromobisphenol A with nanoscaled magnetic CuFe2O4 as a heterogeneous catalyst of peroxymonosulfate

CuFe2O4 magnetic nanoparticles (MNPs) were prepared by sol–gel combustion method with copper and iron nitrates as metal precursors and citrate acid as a complex agent. The obtained CuFe2O4 MNPs were characterized by scanning electron microscopy, X-ray diffractometry, Fourier transform infrared spectroscopy, Fourier transform Raman spectroscopy and X-ray photoelectron spectroscopy. It was found that CuFe2O4 MNPs could effectively catalyze peroxymonosulfate (PMS) to generate sulfate radicals (SO4−) to degrade tetrabromobisphenol A (TBBPA). The added TBBPA (10 mg L−1) was almost completely removed (with a removal of 99%) in 30 min by using 0.1 g L−1 CuFe2O4 MNPs and 0.2 mmol L−1 PMS. With higher addition of PMS (1.5 mmol L−1), the degradation yielded a TOC removal of 56% and a TBBPA debromination ratio of 67%. The effect of catalyst calcination temperature, catalyst load, PMS concentration and reaction temperature was investigated on the catalytic activity of CuFe2O4 MNPs. The highly catalytic activity of CuFe2O4 MNPs possibly involved the activation of PMS by both Cu(II) and Fe(III) in CuFe2O4 MNPs. Based on intermediate detections, the degradation pathway of TBBPA in the CuFe2O4 MNPs/PMS system was proposed.