determination and dispersion modeling of voc emissions from liquid storage tanks in asalouyeh zone

air pollution is one of the most challengeable problems in the asalouyeh zone. in order to reduce the air pollutants emission and their effects it is necessary to recognize the amount and spatial dispersion of air pollutants. hence in this paper, evaporative losses of the stored liquids from 16 tanks of an oil company in asalouyeh zone, are determined using tanks 4.0.9d and then dispersion of vocs emission from storage tanks are simulated by aermod model and over an area with dimension of with resolution of 150 m and in 5 vertical layers including ground surface, 2 m, 10 m, 20 m and 30 m layers. model is run for 12 months meteorological data (year 2009) and simulation was done for 1 hr, 3 hr, 8 hr, 24 hr, 1 month, and 12 months averaging concentration. as results liquid storage tanks of related company emit 233336987 gr (~ 233 ton) vocs pollutants to atmosphere per year. maximum concentrations occur in 20 m height. spatial dispersion of vocs pollutants shows that at first half of year 2009 north westerly wind (315 degree) was more effective but at second half of year 2009 south easterly wind (135 degree) was prominent.