Dispersion simulation of odorous compounds from waste collection vehicles: Mobile point source simulation with ModOdor

Odour pollution from municipal solid waste is a public nuisance and a threat to the health of residents nearby. Attention and understanding towards odour emissions from waste collection vehicles are insufficient, and dispersion simulation using conventional modelling tools cannot be applied because their special operational characteristics do not conform to either point or linear sources. This study proposes a new dispersion simulation method for mobile point sources with ModOdor, which is a 3D numerical model previously developed by the authors. The 12-month monitoring data show that ethanol, dimethyl disulphide and methylene chloride were identified as typical odorous compounds released from waste collection vehicles. Ethanol dispersion was simulated as a mobile point source for low- and high-speed modes by synchronously changing temporal and spatial grids in high precision. Results revealed the variations in concentration distribution, dispersion distance and impact duration. In general, a diameter of area with odour activity value higher than 0.1 was identified at approximately 30–50 m after stable dispersion. The impact duration varied from approximately 20 s to 40 s along with the tested source intensities, wind directions and speeds with a benchmark of 10 μg·m−3. This study verified the applicability of the proposed method for the dispersion simulation of mobile point sources and provided useful approach and information for evaluating the odour pollution from waste collection vehicles.