US EPA

4244324 

Journal Article 

Assessment of the contributions of the highest NO2 concentrations by industrial sources using AERMOD dispersion model 

Abari, MF; Zarandi, SM; Mansouri, N 

2016 

Yes 

Bulgarian Chemical Communications
ISSN: 0861-9808 

48 

25-32 

WOS:000404015300004 

The Environmental Protection Agency (EPA) recently announced a 1-hour NO2 standard based on the multiyear average of the 98th percentile of the annual distribution of daily maximum 1-hour values, not exceeding 188 mu g/m(3). The AERMOD-the EPA's preferred dispersion model for near-field applications was recently modified to fully support the form of the 1-hour NO2 National Ambient Air Quality Standard (NAAQS), which contains three different NO-to-NO2 conversion methods for estimating the ambient concentrations of NO2. The prevalence of nitrogen oxide (NOx) emissions from the Esfahan Oil Refinery Complex, petrochemical and power plant is in the form of nitric oxide (NO) rather than NO2. NO gases in the emission plume mix with the atmosphere and react with ozone and other oxidants to oxidize a portion of the NO to NO2. In this study, the contribution of industrial groups in randomly selected receptors in all the directions within three, six and 30 kilometres from the centre point were determined in relation to the screening approach of Tier I, assuming full conversion of NO to NO2. The results showed that the cumulative first highest max daily contribution 1-hour value averaged over 1 year (2012) equalled 26.7 and 25.8%, calculated from total NO2 ground level concentration of 590.7 and 571.973 mu g/m(3) in the West and South receptors(3km). Contributions of 15.5 and 10.6% were devoted to the receptors located within 6km and 30 km respectively. While 36 and 50% SE receptor first-highest max concentration were portioned to the petrochemical and refinery, the total of cumulative apportionment in the SW receptor was released from the power plant. The cumulative first-highest max daily contribution of 1-hour value during 2012 reached to 2218.329 (mu g/m(3)); that highest one 88.6% (1966.4 mu g/m(3)(was related to the refinery. As well as, the rank of 50 highest 1-hour NO2 that indicated the exceeding the values of EPA's Standards only distributed in 34 receptors in south and 16 receptors in west over year throughout the domain. The max 1-hour concentration of NO2 in Esfahan city receptor was 73.7 (mu g/m(3)) that was below the standard level. 

EPA; Cumulative; industrial groups; receptor; 1-hour NO2