Distribution trend of BTEX compounds in ambient air of urban solid waste landfill sites and surrounded environment: A case study on Ahvaz, Southwest of Iran

Benzene, Toluene, Ethylbenzene, and Xylene (BTEX) are classified as hazardous air pollutants that have been identified at landfill sites and surrounding environments. Therefore, in the present study, BTEX concentrations were measured at new and old solid waste landfill sites of Ahvaz during cold and warm seasons. As one of the megacities in the southwest of Iran, Ahvaz produces more than 1,000 tons per day of solid waste. The produced solid waste is transported to the new Borumi landfill site, which is located at 31 degrees 17'28 '' N and 31 degrees 18'31 '' N latitude and 48 degrees 48'12 '' N and 48 degrees 50'15 '' longitude. Air samples were taken in both cold and warm seasons from 6 points including, one point in the new site, three points in the old site, a point between two sites, and one point in the city boundary (as background point). Air sampling was performed in the prevailing wind direction (the southeast wind), and the meteorological parameters, including temperature and relative humidity, were also measured during air sampling. The results showed that the emission rate of BTEX compounds in the old and new landfill sites of Ahvaz is considerable. So that, the highest concentrations in the old landfill site in the warm season for benzene, toluene, ethyl-benzene, and xylene were 173.82, 234.51, 246.18, and 20.84 ppm, respectively. However, these values in the cold season were 16.6, 50.04, 2, and 70.28 ppm, respectively. It shows that the concentration levels of BTEX were significantly higher in the warm season compared to the cold one