Degradation of trans-ferulic acid in aqueous solution by a water falling film DBD reactor: Degradation performance, response surface methodology, reactive species analysis and toxicity evaluation

Abstract

In this study, a water falling film dielectric barrier discharge (DBD) reactor was used to degrade trans-ferulic acid (FA) in water. The results show that 98.4% of FA was degraded by 10 min treatment with the discharge voltage of 19 kV. The reactor displayed an excellent energy efficiency, which could reach to 13.4 g/kWh for FA degradation. Degradation characteristics of the water falling film DBD for FA was studied by single factor experiments and response surface methodology. The optimal operating condition and a quadratic polynomial equation for predicting FA degradation efficiency were obtained by the response surface model. The reactive species analysis unveils that the peroxone reaction between H2O2 and O3 generated by DBD could promote the formation of OH, causing a synergistic effect for FA degradation. Hydrated electron (eaq−) converted into H in FA solution. In the present reaction system, H preferred to react with FA rather than merge with OH, and H showed a well ability to degrade FA. FA solution toxicity was weakened after DBD treatment.