Effect of the presence of inorganic anions on the degradation of phenol by dielectric barrier discharge plasma combined with RGO-TiO2

Abstract

In this study, RGO-TiO2 composites was combined with dielectric barrier discharge plasma for phenol degradation, and the effects of initial reaction conditions and some concomitant inorganic anions (Cl−, CO32−, SO42− and NO3−) on the removal efficiency of phenol were investigated. RGO-TiO2 composite materials were prepared by sol-gel method and characterized by XRD, SEM, FTIR and PL firstly. The experimental results showed that when the input voltage was 90 V and the catalyst dosage was 1.5 g/L, the removal efficiency of 1.06 mM phenol reached 94.7 % after 20 min during reaction. The presence of Cl− and SO42− had a significant inhibitory effect on the degradation of phenol at low concentration, while the inhibitory effect of NO3− could be ignored. Surprisingly, after 10 mM CO32− added, the synergetic system completely degraded the phenol solution within 16 min. The radical quenching experiments was carried out, and the variation of O3 and H2O2 during the degradation of phenol were detected. Finally, the intermediate products of phenol degradation were analyzed by HR-LC–MS, and the possible degradation path of phenol was proposed.