BIOLOGICAL ELIMINATION OF VOCS IN BIOFILTER

A laboratory scale biofilter system was used to eliminate toluene and ethanol, the main solvents employed in lacquering, from waste air. A s pecific micro-flora (mixture of Bacillus for ethanol and two pseudomon as species for toluene) able to degrade ethanol and toluene, was fixed on a packed bed of particles of commercial peat intermittently humidi fied by a nutrient solution necessary for the survival of the micro-or ganisms. In the experiments, polluted gas was fed upwards through the bed and physical parameters: moisture content of peat; humidity of air ; temperature; pressure drop inlet/outlet concentration of gas and mic robial population were measured regularly in order to check the perfor mance of-the biodegradation process. These experiments showed good per formance and good stability of the biofilter over time.