Simultaneous removal of ethyl acetate and toluene in air streams using compost-based biofilters

Biofitration was successfully applied to treat air streams containing a mixture of ethyl acetate and toluene. The experiment was performed by two identical bench-scale biofilters, which were acclimated by ethyl acetate and toluene, respectively. During a 3 month steady-state performance, the two biofilters showed equivalent elimination capacity (EC) for toluene (50 g/m(3) bed/h of pure toluene). However, the biofilter acclimated with ethyl acetate showed a much higher EC for ethyl acetate (400 g/m(3) bed/h of pure ethyl acetate) than that acclimated with toluene (250 g/m(3) bed/h). The concurrent biofiltration of toluene was inhibited by the presence of ethyl acetate. The results also showed that more nitrogen and phosphorus were consumed in the process of the biofiltration of toluene compared with the treatment of ethyl acetate. After the 3 month experiment, the pH of the media treating ethyl acetate dropped from 6.71 to 5.50, whereas the pH of the media treating toluene increased from 6.71 to 7.08.