DBD plasma coupling MnO2-Fe3O4-cellulose acetate films for sulfamethoxazole degradation: Insight for catalytic ozonation and Fenton effect

Abstract

In this study, efficient degradation of sulfamethoxazole (SMX) by coupling dielectric barrier discharge (DBD) plasma and MnO2-Fe3O4-cellulose acetate (MnO2-Fe3O4-CA) film catalyst was investigated. SEM, XRD, FT-IR and XPS were carried out to confirm the successful preparation of the MnO2-Fe3O4-CA film. The optimal constitution of MnO2-Fe3O4 and CA was evaluated according to the SMX degradation under different conditions of the prepared films. When 3 % 3:1 MnO2-Fe3O4-CA films were added into the DBD system, the removal rate of SMX could reach 93.55 %. Experiments on the effect of the initial pH value of the solution indicated that the SMX degradation was better under both neutral and alkaline solution conditions. Mechanism analysis show that ·OH, ·O2− and 1O2 were involved in the degradation of SMX. The MnO2-Fe3O4-CA catalyst could burst Fenton reaction and promote ozone decomposition, and accordingly generated more reactive oxygen species (ROS) responsible for the increase of the SMX degradation. The cyclic experiments showed that film had good repeatability and stability. Four routes of SMX degradation were given according to the byproducts analysis, and the toxicity was evaluated.