A bacterial consortium with complementary metabolic capabilities was formulated and specific removal rates were 0.14, 0.35, 0.04, and 0.39 h(-1) for benzene, toluene, o-xylene, and m, p-xylene, respectively. When immobilized on a porous peat moss biofilter, removal of all five (= BTX) components was observed with rates of 1.8-15.4 g m(-3) filter bed h(-1). Elimination capacities with respect to the inlet gas concentrations of BTX and airflow rates showed diffusive regimes in the tested concentration range of (0.1-5.3 g m-(3)) and airflow (0.55-1.82 m(3) m(-2) h(-1)) except for o-xylene which reached its critical gas concentration at 0.3 g m(-3).