Vol.:(0123456789) 1 3 Earth Systems and Environment https://doi.org/10.1007/s41748-019-00087-z ORIGINAL ARTICLE Simulation of Point Source Pollutant Dispersion Pattern: An Investigation of Efects of Prevailing Local Weather Conditions Olaniran. J. Matthew 1  · Abigail N. Igbayo 1  · Felix S. Olise 2  · Kayode O. Owoade 2  · Olawale E. Abiye 3  · Muritala A. Ayoola 2  · Philip K. Hopke 4 Received: 8 September 2018 / Accepted: 10 January 2019 © King Abdulaziz University and Springer Nature Switzerland AG 2019 Abstract This study investigated the potential efects 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/Environ- mental 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 fne PM, i.e., PM 2.5 (mean error = − 6441 µg m −3 , kappa coefcient, κ = 0.31 at M1 and mean error = − 16,608 µg m −3 , κ = 0.41 at M2) and the coarse, i.e., PM 2.5–10 (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 efective plume rise which resulted in a decrease in atmospheric pollutant concentration. The study has implication in industrial air pollution reduction. Keywords AERMOD · Particulate matter · Emission source · Dispersion · Atmospheric conditions 1 Introduction Particulate matter (PM) is the most critical pollutant with respect to its impacts on human health and the environ- ment. It is emitted by a wide range of man-made sources. The most signifcant primary sources were road transport, non-combustion industrial processes, industrial combustion plants and power generation (Cretu et al. 2010). It is usually characterized into two size fractions: fne (PM 2.5 —diameter of less than 2.5 micrometers, μm) and coarse (PM 2.5–10 — diameter between 2.5 and 10 μm) (Rickun 1993; Cretu et al. 2010). In the absence of precipitation, fne PM has a lifetime of multiple days in the atmosphere and it can undergo long- range transportation over hundreds of kilometers (Seigneur 2001). This is so because the particles have negligible small aerodynamic diameter and slow dry deposition rates. In the contrary, coarse particles can settle more rapidly (within hours) and normally travel only shorter distances (USEPA 2004). The basic climatic factors afecting dispersion, chemi- cal reaction, and deposition of pollutants are wind speed, atmospheric stability, solar radiation, precipitation, and humidity. These factors have been found to have signifcant efects on concentration of air pollutants in the ambient air (Qin and Oduyemi 2003; Awasthia et al. 2006; Cretu et al. 2010; Cretu and Deaconu 2012; Goudarzi et al. 2017). Other infuencing factors include the physical location of the stack, nature of the terrain downwind of the stack and its character- istics (Norman 1984; Pohjola et al. 2000). Wind dilutes pol- lutants and rapidly disperses them throughout the immediate * Olaniran. J. Matthew abefematt@yahoo.com 1 Institute of Ecology and Environmental Studies, Obafemi Awolowo University, Ile-Ife, Nigeria 2 Department of Physics and Engineering Physics, Obafemi Awolowo University, Ile-Ife, Nigeria 3 Centre for Energy Research and Development, Obafemi Awolowo University, Ile-Ife, Nigeria 4 Department of Chemical and Bimolecular Engineering and Center for Air Resources Engineering and Science, Clarkson University, Potsdam, NY 13699-5708, USA