Estimation of Benzene from Storage Tanks and Determination of the Permissible Distance from Gas Stations

Benzene is considered a toxic and hazardous pollutant in Tehran metropolis. The storage tanks of petroleum products and refueling in gas stations are among the main sources of benzene emissions. Using the software AERMOD and reviewing the benzene dispersion maps at different distances from 412 storage tanks at 148 gas stations, it was found the permissible distance of the emission source is dependent on various variables such as the number of loading times and the storage capacity. When, storage capacity in the range of 60,000 L to 96,000 L and the number of loading is in the range of 675 to 1328 times a year, the concentration of benzene at a distance of 30 m of the emission source reaches the annual standard of 5 μg/ m3. While, storage capacity in the range of 80,000 L to 128,000 L and the number of loading is in the range of 1329 to 1834 times a year, the concentration of benzene at a distance of 40 m of the emission source reaches the annual standard of 5 μg/ m3. Also, based on the analysis of data and the linear regression equation, the permissible distance of the emission source can be predicted.