Efficient removal of levofloxacin from different water matrices via simultaneous adsorption and photocatalysis using a magnetic Ag3PO4/rGO/CoFe2O4 catalyst.

A magnetic Ag3PO4/rGO/CoFe2O4 ternary catalyst was firstly prepared and used for removing levofloxacin (LVF) from different water matrices via simultaneous adsorption and photocatalysis. Compared with Ag3PO4 and Ag3PO4/CoFe2O4, Ag3PO4/rGO/CoFe2O4 shows a superior adsorption-photocatalysis performance for LVF elimination since rGO component not only improves the adsorption ability but also enhances the charge separation efficiency of the catalyst. About 90.7% of LVF in distilled water (10 mg/L) was removed by the ternary catalyst after adsorption for 0.5 h and photocatalysis for 1.0 h, and the removal of LVF performed well in the pH range of 3.51-9.47. Singlet oxygen (1O2) was the major reactive oxygen species for LVF degradation in Ag3PO4/rGO/CoFe2O4 system under visible light, as confirmed by the quenching experiments and ESR study. Based on the detected intermediates in the photocatalytic process, the possible LVF degradation pathways were well-established. As-synthesized Ag3PO4/rGO/CoFe2O4 can also efficiently remove LVF from the different real water matrices (river water, lake water and secondary effluent) via simultaneous adsorption and photocatalysis. Moreover, magnetic Ag3PO4/rGO/CoFe2O4 can be easily recovered and effectively reused for the removal of LVF in actual water bodies.