Unraveling the degradation of levofloxacin using highly efficient β-cyclodextrin-modified copper ferrite through peroxymonosulfate activation: Mechanistic performance and degradation pathways

In this study, a highly magnetic β-cyclodextrin-modified copper ferrite (CuFe₂O₄@β-CD) catalyst was developed utilizing a hydrothermal method, which was subsequently utilized to degrade Levofloxacin (LEV) antibiotic in aqueous solution via heterogeneous activation of peroxymonosulfate (PMS). The findings demonstrated that the 98.87 % degradation of LEV was achieved with CuFe₂O₄@β-CD/PMS, much higher than that of pure CuFe₂O₄/PMS (87.78 %) within a 24-minute time frame under optimal parameters ([CuFe₂O₄@β-CD] = 0.4 g/L, [PMS] = 0.4 mM, [LEV] = 25 mg/L, pH = 6), and CuFe₂O₄@β-CD/PMS was present. The rate constant of CuFe₂O₄@β-CD/PMS (0.1608 min⁻¹) was much greater than that of the CuFe₂O₄/PMS system (0.0822 min⁻¹). The increased availability of active sites for PMS activation may be credited to the larger surface area (189.42 m²/g) of the CuFe₂O₄@β-CD catalyst in comparison to the pristine CuFe₂O₄ (87.76 m²/g), which facilitated the improved degradation of LEV. Additionally, the impact of various reaction parameters and intervening anions on the degradation of LEV was investigated. The emergence of free radicals (SO₄^•−, ^•OH, and ¹O₂) was corroborated via electron paramagnetic resonance and scavenging experiments. On the basis of recognizing reaction intermediates, a hypothetical degradation mechanism for LEV was developed. PMS activation was caused by the transformation of Cu⁺/Cu²⁺ and Fe³⁺/Fe²⁺ pairs, which was accomplished via radical and non-radical pathways. Also, CuFe₂O₄@β-CD demonstrated exceptional stability and retained its catalytic activity after five concurrent cycles. In conclusion, the CuFe₂O₄@β-CD catalyst demonstrated encouraging potential in the context of purifying LEV-contaminated water.