Insight into the photothermal boosted ofloxacin removal by magnetic CuFe2O4/pyrite waste catalyst: Mechanism, degradation pathways, and toxicity evaluation

Abstract

The widespread distribution of antibiotics in natural waters has raised global concerns due to their potential threat to the aquatic environment. In this study, 40 %-CuFe2O4/pyrite waste composite material was constructed for the removal of ofloxacin (OFX) through activating H2O2 in photothermal Fenton processes. It had excellent photothermal conversion performance and could serve as a superior photothermal-Fenton catalyst. The removal efficiency of OFX was 96.13 % in the photothermal Fenton reaction, and the apparent first-order kinetics rate constant (k) was 4.33 and 12.15 times higher than in the traditional Fenton without light and 40 %-Fe/PW photothermal Fenton reaction. This could be attributed to the introduction of photothermal effect promoted collisions between substances, and expedited the reaction rate. The redox cycle of Fe(II)/Fe(III) and Cu(I)/Cu(II) in the Cu-Fe bimetal system also contributed to the removal of OFX. Besides, it exhibited excellent cycling stability, extensive adaptability for various pollutants and water properties. The order of contribution of active radicals to the removal of OFX was ∙ OH>h+ >∙O2-, and they attacked the active atoms of OFX molecule with high Fukui index. Hopefully, this study may encourage the utilization of the photothermal effect for contaminant removal and introduce a novel perspective for environmental remediation.