Conditions for the use of biological filters

• The waste air pollutants must be water-soluble.
• The waste air pollutants should serve as substrate for the micro-organisms (i.e. they must be biologically degradable).
• The properties of waste air and the substances it contains should not disturb the biological degradation.
• A sufficiently large quantity of oxygen should be available for the oxidation of the pollutants.
• The waste air incoming temperature should be somewhere between 5° and 60°C.
• The entering waste air should be saturated with water
  (relative humidity > 95 %).
• The waste air should not contain large quantities of dust and oily/greasy aerosols.

Wate air should therefore first pass through a conditioning device before it enters the biological filter.