Estimates and Simulation of Air Pollution Mitigation with Green Roofs (Case Study: Tehran Nature Bridge)

Green roof has been applied in modern cities around the world to mitigate urban heat island, air pollution, storm water and noise pollution. In current study was focused on the entrapment of pollutants by green roof, therefore ENVI-met software was used to simulate the interaction between atmosphere and green roof installed on Tehran Nature Bridge. This study was carried out on 28th march 2015 on the Nature Bridge, it is the largest pedestrian bridge in Iran, with intensive and extensive green roof are installed on top of the bridge. There are stationary sources of pollutants in this simulation representing cars under the bridge. Emission rate for each pollutant was determined in every hour of the day. In rush hour, 4 pm, the highest amount of deposed Particle matter (PM), Carbon monoxide (CO) and Nitrogen dioxide (NO2) on northern extensive green roof were recorded 0.05 µg/m2, 0.31 µg/m2 and 2.37 g/m2,respectively. The results showed, the deposed pollutants on the intensive and southern extensive green roof were much lower than the northern extensive green roof of the Nature Bridge.