GASEOUS TOLUENE REMOVAL BY A TWO-STAGE ADSORPTION-PLASMA HYBRID SYSTEM

In this paper, a two-stage adsorption-plasma hybrid system was used to remove toluene. When the adsorbed toluene level is low, toluene can be completely oxidized. For a high adsorbed toluene amount, toluene emission is observed in oxidation stage. It was demonstrated that oxygen plasma exhibited the better oxidation effect without nitrogen oxide formation compared with the oxidation effect by air plasma. It was deduced that ozone and other radical species (center dot OH, HO2., etc.) derived from water played the dominant role in the oxidation of the adsorbed toluene. A linear relationship was also observed between CO production and ozone consumption in the oxidation stage. In addition, we proposed a kinetics model to describe the oxidation behaviors of adsorbed toluene. It was observed that the decomposition of the adsorbed toluene was consistent with two-stage L-H model in plasma oxidation stage. It was deduced that the two stages are successively controlled by the formation rate and diffusion of reactive species, respectively.