Simulation of Point Source Pollutant Dispersion Pattern: An Investigation of Effects of Prevailing Local Weather Conditions

Abstract

This study investigated the potential effects of prevailing local atmospheric conditions on dispersion pattern of point source emissions from a Scrap-Iron and Steel Smelting Factory, Ile-Ife, Nigeria. The American Meteorological Society/Environmental Protection Agency Regulatory Model (AERMOD) was adopted to predict the atmospheric dispersion of particulate matter (PM) emissions around the source. The PM estimates at two experimental points (M1 and M2) around the source were compared with the observations. The model simulations suggested that the PM was mostly dispersed by the dominant southwesterly wind such that the plume moved towards the northeast with variations in their spatial distributions across the seasons. Under low wind speeds and humid conditions, there was accumulation of the pollutants within the periphery of the point source. The simulated pollutant concentrations compared fairly well with the observations for both fine PM, i.e., PM2.5 (mean error = − 6441 µg m−3, kappa coefficient, κ = 0.31 at M1 and mean error = − 16,608 µg m−3, κ = 0.41 at M2) and the coarse, i.e., PM2.5–10 (mean error = − 5506 µg m−3, κ = 0.27 at M1 and mean error = − 4174 µg m−3, κ = 0.36 at M2). A hypothetical increase in stack height enhanced effective plume rise which resulted in a decrease in atmospheric pollutant concentration. The study has implication in industrial air pollution reduction.