Corresponding VDI guideline: VDI 3478, 2

• pH control
• No use of oxidants
• Optimal pre-treatment unit in front of a biofilter
• Little space demand / compact size
• Low pressure loss
• Corrosion resistant
• Weather resistant
• Low risk of plugging due to the structure of the packing material
• Easy overview and easy handling of the display

Another factor to be kept in mind with biotrickling filtration, is the fact that the biofilm is not in a natural system serving as store for nutrients. During the design and control of the system it should also be noted that the growth inhibition of the microorganisms is suppressed in the aquatic system. According to this the balance between new cells and old cells in not given anymore. Therefore the good bacterial growth is to be controlled. It is possible to eliminate the old biomass through periodic increase of the spraying rate. Another possibility to avoid plugging on the packing material, is the limitation of N- and P-containing nutrients.