The material used in the AERNET biofilters as been selected for the modern second generation biofilters, and it makes use of the reamarkable experience gained with the realized and since long regularly functioning plants.

A research has been carried out on the material to avoid problems such as degradation with squashing and obstruction of the bottom of the beds caused by the normally used materials.
These degradation problems are responsible, in the short time, for the formation of preferential ways on the biological bed and an exponential increase in the filtering stratum load loss; this causes a corresponding increase in fan wear and a reduction of the oeprative capacity of the bed until the complete unserviceability of the biofilter.
To avoid these consequences, the filtering bed consists of three different stratums named BIO1, BIO2, and BIOMIX.

By using three filtering beds not only are resolved problems of putrefaction, squashing, and obstruction of the lower part of the filters (leading to higher wear, bad functioning, or short duration of the material) but can also be easily realized high efficiency high stratum (up to 2 mt.) biofilters, necessary for higher performance or high concentrations.

The material has already been tested and successfully used to knock down odours coming from waste water depuration plants and relevant mud treatment and also for much more hard tasks such as odours coming from solid waste treatment (composting), from meat and fish reject processing (rendering), from coffe, tobacco, hides, and generic food processing.