Dispersion Modeling of Nitrogen Dioxide in Ambient Air of Ahvaz City

Background: air emission modeling is used to study how pollutants are spread in the environment and to forecast their emissions rate in different climatic conditions in the study area. today, air pollution threatens human public health and the environment, and ahvaz is considered one of the main centers of air pollution in iran. objectives: this aim of this study was to evaluate the nitrogen dioxide distribution in ahvaz by using the software program screen 3. materials and methods: this analytical study was conducted in 2013 in ahvaz. data collections were performed by the ahvaz department of environment. after processing the data received (averaging instruction set, coding), the file was converted to an input file for the software program screen 3. in the next phase, study of the distribution and release of nitrogen dioxide during the year 2013 was modeled using the screen 3 software. results: based on the results of this study, the highest and the lowest nitrogen dioxide concentration were in the bureau of meteorology and head office of adoe stations, respectively. the maximum concentration of no2, at a height of 45 m, was 20 μg/m³.according to the findings of the modeling, examination of the combustion process was observed, and this was caused by the amount of nitrogen dioxide emitted by flue outlets, which was affected by temperature and pressure, fuel flow rates and inlet air temperature. also, results showed that in most cases emission of air pollutants was towards the southwest. conclusions: results of this study showed that the screen3 software is one of the popular models for estimating the distribution of air pollutants. nitrogen dioxide emissions are highly regulated in most industrialized regions. decreased emissions from fuel combustion, the use of scrubbers and filters that absorb pollution can be very useful for reduction and control of nitrogen dioxide emissions.