Document Type : scientific-research article
Authors
Abstract
Acid rain has become a big problem for urban areas during recent decades. Acid rain originates from high concentration of air pollutants including man made or artificial and natural ones in the atmosphere. As the biggest religious city in Iran, Mashhad also suffers from this problem. In this investigation sample rains collected during autumn 2002 and spring 2003 were analyzed. The results show that concentration of different ions (SO4 -2, NO2-, NO3-, and NH4-) is higher than normal. By employing the concentration of ions and average precipitation in Mashhad, the amount of wet acid deposition was calculated. Based on this calculation, the rate of acid that comes to the ground due to the rainfall is more than 24 Kg/h. Unfortunately, we have no access to any critical load map for our terrain of interest to estimate the hazard. A comparison of the wet deposition amount in Mashhad and North Wales in the UK, however, shows that the wet deposition of acids in Mashhad is nearly the same as Wales, a very polluted area in UK. If we assume that the amount of dry deposition is similar to wet deposition we can get an idea about the amount acid that comes to the ground during each year. The results of this research, therefore, call for paying more attention to Mashhad environmental affairs.
Key Words: Acid Rain, Acid Concentration, Wet Deposition
Send comment about this article