SO2 dispersion and monthly evaluation of the industrial source complex short-term (ISCST32) model at Mina Al-Fahal refinery, Sultanate of Oman

Modeling of air pollutant dispersion has been undertaken for emissions of sulfur dioxide (SO2) at the Mina Al-Fahal refinery in the Sultanate of Oman. The study was conducted during the period of November 1999 to October 2000. The Industrial Source Complex Short-Term (ISCST32) air pollution model was adopted to predict the ground level concentration of SO2 in and around the refinery. The modeling results were validated against measured data during the study period. The comparison, based on the monthly average measurements, showed that the model underestimates the observed SO2 concentrations. However, the predicted ground level concentrations of SO2 during the months of September, October, November, and June were in better agreement with the observations. The predicted SO2 values are presented in the form of concentration contours to determine the spatial distribution of SO2 and to assess the impact on air quality over the survey area. Predicted SO2 concentrations were found lower than the World Health Organisation (WHO) guideline value of 365 mug/m(3), with the maximum ground level concentrations being found to occur relatively close to the sources of emission. Moreover, concentration contour patterns for the modeled area vary with changes in meteorological conditions. On the basis of this study, the refinery is not likely to cause any significant deterioration in air quality, and predicted concentrations of SO2 are well below those likely to influence health.