Synergism of adsorption and catalytic degradation of levofloxacin by exfoliated vermiculite anchored with CoFe2O4 particles activating peroxymonosulfate

A multiphase catalyst (CoFe2O4@2D-V) was constructed by loading CoFe2O4 on two-dimensional vermiculite surface via hydrothermal synthesis. Levofloxacin (LVX), as a typical antibiotic, was used to estimate the performance of CoFe2O4@2D-V by PMS activation. CoFe2O4@2D-V exhibited an excellent adsorption and degradation performance for LVX. Experimental results showed an 88.6% of LVX removal efficiency and 0.048 min-1 of LVX removal rate obtained in CoFe2O4@2D-V/PMS system under the conditions of a 15 % CoFe2O4 mass ratio (15 %-CoFe2O4@2D-V), initial pH 6.89, [LVX]0 10 mg/L, [Catalyst]0 0.3 g/L, and [PMS]0 0.35 mM. Adsorption removal accounted for 35.1 % of LVX removal. The prominent roles of LVX degradation were radical way mainly contributed by center dot SO4- and non-radical way achieved by 1O2. The redox cycle between Co(III)/Co(II) and Fe(III)/Fe (II) played a crucial role in activating PMS to generate reactive oxygen species (ROS). In addition, 15 %CoFe2O4@2D-V had less ion leakage, high reusability, and excellent adaptability. Four degradation pathways of LVX in 15 %-CoFe2O4@2D-V/PMS system were proposed. ECOSAR evaluation show that LVX and its degradation intermediates pose minimal harm to the ecosystem. 15 %-CoFe2O4@2D-V is an environmentally friendly and efficient catalyst for LVX removal by PMS activation, which may provide a new idea for developing loaded catalysts for antibiotics removal through adsorption and catalysis.