Synergistic catalysis of Cu-CeO2@CA composite film in a circulating DBD plasma system and its effect on ciprofloxacin degradation

In this paper, degradation of ciprofloxacin (CIP) in a circulating dielectric barrier discharge (DBD) plasma system with Cu-CeO2@CA composite films addition was investigated. The Cu-CeO2@CA films were synthesized through hydrothermal method, and the samples were characterized by SEM, XRD, EDS, FT-IR and Raman spectra analysis. The obtained results show that there was synergistic effect of the DBD plasma and the Cu-CeO2@CA films on the CIP degradation and mineralization. The optimal performance was obtained under the condition of 5 wt% Cu-CeO2 nanoparticles doping in the composite film. Besides the effect of the DBD plasma, the Cu-CeO2@CA films could drive the O3 decomposition, photocatalysis and then the more reactive oxygen species (ROS) formation. The presence of the main active species and their contributions to the CIP degradation were determined by electron spin resonance (ESR) analysis and radical quenching experiments. Methods of UV–vis spectrum, three-dimensional fluorescence spectrum and liquid chromatography mass spectrometry (LC-MS) were used to analyze the CIP decomposition process. The prepared Cu-CeO2@CA composite films had certain stability in the four cycles of application and the film catalyst was convenient for recycling. The toxicity evaluation results indicated the decline of the solution toxicity after treating in the Cu-CeO2@CA/DBD system.