Decomposition of chlorinated volatile organic compounds (CVOCs) using NTP coupled with TiO2/GAC, ZnO/GAC, and TiO2-ZnO/GAC in a plasma-assisted catalysis system

No study was found in the literature on the catalytic effect of TiO2/GAC (Granular activated carbon), ZnO/ GAC, and TiO2 ZnO/GAC combined with non-thermal plasma (NTP) for the decomposition of chlorinated volatile organic compounds (CVOCs) in gas streams. In the present study, this catalytic NTP process was investigated to examine the effect of specific input energy (SIE), initial concentration, as well as residence time on the removal efficiency (RE) of CVOCs in a corona discharge reactor energized by a high frequency pulsed power supply. A dip-coating sol gel impregnation technique was used to coat TiO2, ZnO, and mixture of TiO2 ZnO nanoparticles on GAC, which were then combined with NI? in a two-stage configuration. The results revealed that the efficacy of the catalysts was in the order TiO2 ZnO/ GAC Ti02/GAC > ZnO/GAC with chloroform feeding, while when chlorobenzene introduced, the order changed to Ti02 ZnO/GAC > ZnO/GAC > Ti02/GAC. A significant enhancement was observed with RE as catalysts coupled with NTP in all cases and a RE of 100% was achieved in the presence of both Ti02/GAC and Ti02 ZnO/GAC at SIE of ca. 400 J L. Considerable improvement was also noticed for coupling TiO2 and ZnO in both efficiency and catalyst life time. (C) 2014 Elsevier B.V. All rights reserved.