Odour emission factors for the prediction of odour emissions from plants for the mechanical and biological treatment of MSW

In this study, the results of odour concentration measurements sampled from the principal odour sources of 40 dimensionally different and representative Italian waste mechanical and biological treatment (MBT) plants are presented. Experimental data are then used to estimate the odour emission factors (OEFs) relevant to single-process steps. An OEF is a representative value that relates the quantity of odour released to the atmosphere to a specific activity index, which may be for example the waste treatment capacity, the gross weight production, the site surface or a time unit. In this study, the OEFs were calculated as a function of the plant capacity, and expressed in ouE t−1, because of the existence of a proportionality between plant capacity and odour emissions. The results show that the major odour source of a waste MBT plant is represented by the aerobic biological treatment (with an OEF equal to 1.40×108 ouE t−1). In general, the OEFs calculated according to this approach represent a model for a rough prediction of odour emissions independently from the specific characteristics of the different plants.