Degradation of gaseous BTX by biofiltration with Phanerochaete chrysosporium

Biodegradation of benzene, toluene, and o-, m-, p-xylenes (BTX) by the white rot fungus, Phanerochaete chrysosporium was studied in a biofilter. P. chrysosporium was cultured under shaking conditions on YMG growth medium and homogenized pre-grown cells were transferred to the biofilter. Glass beads or hydroballs were used as support material for the fungus in the biofilter. A preliminary batch culture experiment showed that all BTX components were degraded simultaneously without any observable substrate interactions, while the rate constant was the highest for p-xylene and lowest for benzene. For the biofiltration of the BTX, the BTX compounds were individually vaporized from 3 glass bottles containing benzene, toluene, and xylenes, respectively, by applying air flow. The vaporized fluxes of the compounds were immediately taken by the air current to the biofilter through the horizontal tube at the rim of the bottles. The BTX compounds were effectively removed without any additional input of carbon source other than the pollutants themselves. The effect of air flow rate (0.026 similar to 0.450 l/h) on the degradation of the compounds was evaluated in the biofilter packed with glass beads. A substantially higher degradation of all the BTX compounds was observed at higher flow rates, suggesting that mass transfer is a limiting factor in the degradation process. At a flow rate of 0.026 l/h, there was no substantial difference in the extent of degradation between the two support media.