3.4. Binary VOCs (benzene-toluene)
The results of the concentration curves (ppm) of VOC emissions for activated carbon and sulfuric acid treated activated carbon are shown in Fig. 5. The breakthrough curve for the adsorption of benzene-toluene mixture obtained in this study is in agreement to this reported in the literature. (Lillo-Rodenas et al., 2005). Initially, the activated carbon was saturated with benzene; after 58 min, toluene was detected from the outlet of the adsorption bed. For 5S-AC, the toluene was detected from outlet of the adsorption bed after 90 min; for 10S-AC, toluene was detected after 96 min. These times were determined to be the difference between the times at which the toluene outlet concentrations separated, i.e., the separation times of AC, 5S-AC, and 10S-AC were 58 min, 90 min, and 96 min, respectively. This result was shown because of that the adsorption capacity of toluene was higher than that of benzene, that 10S-AC had superior adsorption capacities in the benzene-toluene mixture due to the difference in the breakthrough characteristics of its binary components and the presence of an organic group on the surface.