Wood bark as packing material in a biofilter used for air treatment.

Biotechnology has been applied to find green and low cost environmental processes. In the waste gas treatments (odours and volatile organic compounds VOC) one of the main biological systems used is biofilters. This technology works at normal operating conditions of temperature and pressure, and therefore it is relatively cheap with high efficiencies when the waste gas is characterized by high flow and low pollutant concentration. The aim of this work is to use wood barks (Pinus) as packing material in the biofilter. For this purpose, the influence of various parameters such as residence time of the gas and pollutant loads on removal efficiencies was studied for a biofilter pilot unit. Ethanol, methyl ethyl ketone, dichloromethane and toluene were used as pollutant compounds, because they are representative of both volatile organic compounds. Packing material stability and good biodegradation performances were found.