ABSTRACT
Biofiltration is an air treatment process widely used to remove odorous pollutants from air. Based on the ability of micro-organisms to degrade pollutants, biofilters are particularly suitable for the treatment of hydrogen sulphide (H2S) emitted in wastewater treatment plant atmosphere. Well designed and operated, they permit to obtain very good H2S removals with low working costs. However, some problems exist and some improvements are still necessary: for example, biofilters are often badly watered on sites or packing materials become compact with time resulting in higher pressure drop, preferential air paths.
