In Italy the production of bituminous conglomerates (BC) has no specific guidelines for odour emissions. Bitumen fumes contain particulates, hydrocarbons (VOC) and hydrogen sulphide (H2S) and the quantity of fumes depends on bitumen quality, the handling and storage of the bitumen and inert material. Different VOC formation, including odorants, depends on various parameters such as the asphalt temperature, the asphalt oxidation, and the humidity of air, and large variations are observed under different operational parameters. Currently authorizations and permits for binder and hot mix plants are generally limited to pollutants in stack emissions, like particulate matter (PM), total hydrocarbons (THC) and polycyclic aromatic hydrocarbons (PAH). Like other industrial activities, BC production plants are facing increasing difficulty in coexistence with residents in the vicinity of production facilities due to odour emissions (Palmiotto et al., 2014).
Production plants use different technologies and odour emissions occur not only through the stack, were fumes coming from hot mixing of a bituminous binder with mineral stone sand and filler are emitted, but also from diffuse uncontrolled emissions, due to storage and handling operations of bitumen at high temperatures.
In this work we present data from different monitoring campaigns focussed on odour emissions from hot mix asphalt (HMA) manufacturing facilities, that will be used to quantitatively describe this specific industry sector or category, i.e. a group of similar emitting sources. The final objective will be the definition of emission factors regarding HMA odour emissions, possibly also with a specific odour emission factor estimated per tons of product in view of the possible publication of Lombardy Regional Guidelines on HMA odour emissions characterization and mitigation.