Ultra-fast degradation of ciprofloxacin by the peroxymonosulfate activation using a Co/Al-LDH decorated magnetic hydrochar: Structural design, catalytic performance and synergistic effects

Abstract

CoFe2O4/BHC-LDH3 catalyst was constructed by decoration of Co/Al layered double hydroxides (Co/Al-LDH) on bamboo hydrochar (BHC) loaded with magnetic CoFe2O4 to activate peroxymonosulfate (PMS) for ciprofloxacin (CIP) degradation. Taking advantage of structural modulation and synergistic effects between the multi-components, CoFe2O4/BHC-LDH3 demonstrated high efficient PMS activation and ultra-fast CIP removal (91.50 % within 10 min), compared with BHC (6.26 %), CoFe2O4 (26.32 %), and Co/Al-LDH (40.10 %). Both free radical (SO4–) and non-radical (1O2) were crucial during the degradation process, and a substantial decrease in aquatic toxicity of the intermediates was observed. Additionally, the stability of CoFe2O4/BHC-LDH3 in actual water environment was tested using a fixed-bed reactor, illustrating the CoFe2O4/BHC-LDH3 has good stability and anti-interference ability in long-term operation. Possible degradation pathways of CIP in the CoFe2O4/BHC-LDH3 + PMS system were proposed based on liquid chromatography-mass spectrometer analysis and density functional theory calculation. This work provides new strategies for hydrochar-supported catalyst synthesis for organic pollutants decomposition.