S compds.-contg. air from a wastewater treatment plant was wetted to the humidity of 95% at -2 degrees C to 27 degrees C and filtered through oak chip, biomass and bark beds at 10-21 degrees C. The efficiency of the air deodorization increased with the increasing the inlet air and biofilter temps. Neither pH nor moisture content in the biofilter material showed any effect on the air deodorization efficiency.