In this study, a laboratory-scale activated sludge reactor and a biotrickling filter were constructed to study the removal of methyl tert-butyl ether (MTBE) from air vented from contaminated sites. The activated sludge tank (0.4 m¡Ñ0.4 m cross-sectional area, 3.0 m height, and 480 L total volume) was made by acrylic resin. A mixed liquor suspended solids (MLSS) concentration of 2000-3000 mg/L was maintained in the experimental mixed liquor and the sludge was acclimated for 30 days under selected conditions of a Food to Microorganism Ratio (F/M) of 0.3 g BOD/(g MLSS¡Dday) and an influent gas MTBE concentration (C0) of 180 mg/Am3 (@27oC). Results on performance tests show that an average MTBE removal efficiency of 93.6% was obtained with the operation conditions of C0 of 610 mg/Am3 (@27oC), volumetric aeration rate of 0.063 m3/m3¡Dmin, MLSS of 2600 mg/L, and submerged liquid depth of 1.0 m. The biotrickling filter was made by combining two same type of acrylic resin columns (each 0.2 m inner diameter, 2.0 m height, and packed with 900 pieces of polypropylene Pall rings to a height of 1.35 m) in series for the test gas flow and in-parallel for the trickling liquid flow. Each test was operated for 8 hours to reach a steady state for a set of selected conditions (gas flow rate 0.050 m3/min and superficial gas velocity 0.027 m/s, trickling liquid flow rate 0.004 m3/min and pH: 6.8-7.2, and liquid/gas flow ratio: 80 L/m3). Results show that the MTBE removal efficiencies from the influent gas were 40%, 22% and 15%, respectively, with C0 of 50,100 and 230 mg/Am3 (@27oC).