An insightful analysis of dimethyl phthalate degradation by the collaborative process of DBD plasma and Graphene-WO3 nanocomposites

Abstract

In this paper, the prepared graphene-WO3 nanocomposites (rGO-WO3) were added into a dielectric barrier discharge (DBD) plasma system with spiral discharge electrode to set up a collaborative process to treat the dimethyl phthalate (DMP) in water. Degradation of the DMP under different experimental conditions were studied to illustrate the catalysis of the rGO-WO3 in the DBD plasma system. The obtained results proved that there was the catalysis of the rGO-WO3 for the DMP degradation within the studied DMP concentration, solution initial pH values and conductivities. From the results of the energy utilization efficiency (G50) analysis, the catalysis was more apparent in the case of the oxygen bubbling system than that in the nitrogen or the air bubbling system, which was due to the higher oxygen constitution in the oxygen bubbling system. The reduction of the measured liquid phase ozone concentrations in the DBD/rGO-WO3 system bubbled with air as well as oxygen than those measured in the sole DBD system, which verified the consumption of the ozone by the catalysis of the rGO-WO3. Furthermore, the UV–Vis and the three-dimensional fluorescence spectra analysis were also carried out to state the catalytic effect of the rGO-WO3 for the DMP degradation. Toxicity analysis for the degradation byproducts confirmed the collaborative process could reduce the negative effect of the original DMP on the environment.