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

• TiO2 and ZnO impregnated on GAC were coupled with NTP for CVOCs destruction in air.
• SIE increasing had a significant positive effect on the removal efficiency.
• TiO2–ZnO/GAC showed a high performance in both O3 destruction and removal efficiency.

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 NTP in a two-stage configuration. The results revealed that the efficacy of the catalysts was in the order TiO2–ZnO/GAC ≅ TiO2/GAC > ZnO/GAC with chloroform feeding, while when chlorobenzene introduced, the order changed to TiO2–ZnO/GAC > ZnO/GAC > TiO2/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 TiO2/GAC and TiO2–ZnO/GAC at SIE of ca. 400 J L−1. Considerable improvement was also noticed for coupling TiO2 and ZnO in both efficiency and catalyst life time.