A Study of Sensitivity of AERMOD Model in Relation to Physical Factors of Stack

Background and amain: The most important global environmental problem, especially in large cities, is air pollution. This is regarded as a serious threat to human, society and environment health. This paper aims to investigate the physical factors of stack affecting the concentrations of the pollutants through the AERMOD model. In this research, modeling was carried out for four factories Orchin, Khayyam, Noavaran and Meybod Tile Company during the first six months of 2015. The study area comprised 20 × 20 km2., being centered on the Khayyam factory. Meybod meteorological data were used in the form of a three-hour mean status to perform the sub-model of AERMET. A Digital Elevation Model (DEM; SRTM 50 m) was used to perform the sub-model of AERMAP. In order to conduct the statistical analyses, the SPSS software program (Version 22) was used. The results of the statistical analyses showed that the abovementioned factories had significant differences in terms of dispersion of particles: The Noavaran Factory and Meybod Tile Company had the maximum and minimum concentrations respectively. Finally, the model was verified by measuring 23 points in different months with an environmental device. According to the obtained results, the correlation results, the results of the model, and the samples areas were confirmed with P-value=0.002. According to the results of Freidman ranking, the physical factors of the factories affecting the concentration of the particles in order of priority were the stack diameter, the exit rate of suspended particles, the exit speed of the particles, the height of the stack, the temperature of the stack, and the receiver’s height.