Degradation of ciprofloxacin by magnetic CuS/MnFe2O4 catalysts efficiently activated peroxymonosulfate

Background Ciprofloxacin (CIP) is a broad-spectrum antibacterial agent. Its extensive use has led to high frequency detection in various water environments, resulting in environmental pollution. The peroxymonosulfate-based advanced oxidation processes (PMS-AOPs) is a promising method for the removal of organic pollutants due to its low cost and high redox potential. Methods Magnetic CuS/MnFe 2 O 4 composites were successfully prepared using hydrothermal and solvothermal methods. The catalysts were characterized by XRD, SEM, TEM and VSM, and the degradation efficiency and mechanism of CIP by CuS/MnFe 2 O 4 /PMS system were investigated. Significant findings The results demonstrated that the magnetic CuS/MnFe 2 O 4 composites exhibited superior catalytic performance than pure CuS and pure MnFe 2 O 4 . Under optimized degradation conditions (CuS/MnFe 2 O 4 =15 mg/L, PMS=1 mM, CIP=20 mg/L, initial pH = 5.89, T = 25 ℃), 98.9 % of CIP was degraded within 60 min. Metal ions (Cu, Mn, Fe) on the catalysts surface played an important role in activating PMS, whereas low-sulfur species (S 2− and S n 2− ) promoted the Cu(II)/Cu(I), Mn(III)/Mn(II) and Fe(III)/Fe(II) cycles to accelerate the generation of free radicals. Additionally, S O 4 • − and 1O 2 were considered to be important reactive species in the CuS/MnFe 2 O 4 /PMS system. Finally, the magnetic CuS/MnFe 2 O 4 composites exhibited excellent recyclability and universality.