Biotreatments of odours: control and performances of a biofilter and a bioscrubber

Biotechnology has been applied to find systems to decrease the level of pol lution. The main biological systems used in the deodorisation of waste gase s are biofilters, biotrickling filters and bioscrubbers. These technologies work at normal operating conditions of temperature and pressure, and there fore they are relatively cheap with high efficiencies when the waste gas is characterised by high flow and low concentrations of odorous compounds. Th e aim of this work was to study the influence of different parameters (resi dence time of the gas phase, pollutant loads) of a biofilter and a bioscrub ber on removal efficiencies. Ethanol was used as pollutant compound, becaus e it is representative of both volatile organic compounds and odorous molec ules. The performances of the two biological systems are presented and disc ussed. The use of pressure drop monitoring as a tool to control the operati on of a biofilter and to obtain optimal conditions in a bioscrubber is prop osed.