This study examined the use of a bacterial culture of Ralstonia eutropha in biotriclding filters (BTFs) for styrene vapor removal in the absence and presence of silicone oil (5% v/v). Removal was carried out at 40 degrees C using styrene inlet concentrations of 0.8-3.3 g m(-3) and empty bed residence times (EBRTs) of 1 and 2 min. For single-phase BTF, a removal efficiency (RE) of 95% was achieved at inlet concentrations of <2.5 g m(-3) and at an EBRT of 1 min. The addition of oil to the recirculating solution enhanced styrene elimination under all operating conditions and increased maximum elimination capacity (ECmax) from 70 to 110 g m(-3) h(-1). Results of elemental analysis of microorganisms isolated from the bed of the BTFs and biodegradation equations showed that the ratios of CO2 generation to styrene consumption were 2.60 for single-phase and 4.85 for two-phase BTFs. A comparison of results at 35 degrees C and 40 degrees C showed that the presence of oil decreased the effect of operating temperature on RE. (C) 2015 Elsevier B.V. All rights reserved.