Magnetic CuFe2O4 nanoparticles immobilized on mesoporous alumina as highly efficient peroxymonosulfate activator for enhanced degradation of tetracycline hydrochloride

Nanoscaled magnetic copper ferrite (CuFe2O4) is widely used as a peroxymonosulfate (PMS) activator but suffers from agglomeration owing to its inherent magnetic properties and high surface energy. In this work, spinel structured CuFe2O4 anchored on mesoporous alumina (denoted as CFO@AO) were synthesized, characterized, and applied as a PMS activator for the removal of tetracycline hydrochloride (TC center dot HCl). Approximately 97.5 % of TC center dot HCl was decomposed within 10 min in 30 %-CFO@AO (0.2 g/L)/PMS (0.3 g/L) system, and the corresponding kinetic rate constant of 30 %-CFO@AO/PMS (0.417 min - 1) was around 1.57 times higher than that of CuFe2O4/PMS (0.266 min - 1), which indicating that the existence of synergistic catalysis between CuFe2O4 and Al2O3 enhanced the degradation of TC center dot HCl. Moreover, nano -sized CuFe2O4 were successfully anchored on the surface of Al2O3 because of Fe-O-Al bond, which could account for the enhanced catalytic activity, superior pH flexibility, and high chemical stability and reusability of 30 %-CFO@AO. Quenching experimentals, electron paramagnetic resonance, and methyl phenyl sulfoxide (PMSO) chemical probe assays confirmed that both radical oxidation (center dot OH) and non -radical oxidation (1O2 and Fe(IV)--O) were proposed in the developed CFO@AO/PMS system, and center dot OH played a key role in the process. Meanwhile, the PMS activation mechanism by CFO@AO composite was also analyzed based on the results of adsorption energy, which was calculated via DFT. Based on UPLC-MS technique, a possible degradation pathway for TC center dot HCl destruction in 30 %-CFO@AO/PMS system was proposed. The toxicity assessment showed that the catalytic degradation of TC center dot HCl in 30 %-CFO@AO/PMS system reduced the toxicity of most of degradation intermediates. Present work proved that CuFe2O4@Al2O3 composite is an efficient, environment -friendly, and recyclable heterogeneous catalyst for practical wastewater treatment via PMS activation.