Degradation of toluene in surface dielectric barrier discharge (SDBD) reactor with mesh electrode: Synergistic effect of UV and TiO2 deposited on electrode

Abstract

Combing with photo-catalysis and photo-catalyst, a surface dielectric barrier discharge (SDBD) reactor with a mesh electrode was applied for toluene degradation and a high mineralization was achieved. The degradation performance comparison between SDBD reactors with a mesh and a spring electrode was carried out as well. A significant improvement in carbon balance and CO2 selectivity were obtained in mesh SBDB reactor compared with that of spring's one. For instance, when only plasma was applied, the carbon balance and CO2 selectivity of mesh SDBD reactor were 84% and 42.6%, while only 64.5% and 31.8% in spring one, the carbon balance and CO2 selectivity were improved by 30.3% and 34% at SIE of 300 J L−1, respectively. Synergistic effects of photo-catalysis and photo-catalyst were conducted with a 254 nm UV lamp and TiO2 deposited on the mesh electrode by atmospheric pressure (AP) plasma technology. The results showed that TiO2 and UV irradiation both presented promoting effect on toluene degradation in SDBD reactor with mesh electrode. According to the experimental results, the carbon balance rose to 89.5% and 93.9% at SIE of 300 J L−1, when UV or TiO2 was applied. With the application of TiO2 and UV together, a highest carbon balance of 95.9% was obtained at the same SIE. At the same SIE, the CO2 selectivity was promoted by 42.8% or 55.3% with the application of UV or TiO2, and the promotion finally reached at 59.1% when TiO2 and UV were applied together. Additionally, the degradation efficiency of toluene was also enhanced with the introduction of TiO2 and UV irradiation. Increases in toluene degradation efficiency of 19. 7% and 26.8% were obtained at SIE of 300 J L−1, respectively. When both TiO2 and UV were applied, the enhancement could rise to 41.6%.