Abstract
AbstractAerobic biodegradation of benzene, toluene and xylene [BTX] in a biofilm system was investigated. The diameter and height of the biofilter were 4 cm and 75 cm, respectively. Granular active carbon particles were used as the packing material, and the packed bed height was 55 cm. Gases containing single compound or mixtures of BTX were treated in the biofilter by a specific microorganism. The concentrations of BTX were measured by a GC 14A with an FID as the detector, while that of CO2 was measured by a GC 8A with a TCD as the detector. Seven gas flow rates, 30.9、 82.2、 159.1、 236.0、 312.9、 389.9、 466.8 ml/min, were tested for single compound with inlet concentration ranging from 0.1~20 g/m3. Four gas flow rates, 82.2、 159.1、 236.0、 312.9 ml/min, were tested for mixtures with inlet concentration ranging from 0.1~10 g/m3. The results obtained in this study showed that both the removal efficiency and elimination capacity decreased for high gas flow rates. A decrease in the removal efficiency was noticed for high BTX inlet concentrations. The elimination capacity and CO2 production increased for high loading rates. Moreover, an increase in CO2 produced per units of filter media volume and time was noticed for high elimination capacity. Furthermore, the biofilter was proved to be highly efficient in the removal of single compound at a gas flow rate of 30.9 ml/min, corresponding to an empty bed retention time of 18.3 min, and of the mixtures at a gas flow rate of 82.2 ml/min, corresponding to an empty bed retention time of 6.9 min.