Patterns of SO2 emissions: a refinery case study

Air quality modelling is an essential tool for most air pollution studies and the introduction of SO2 standards creates a need for modelling the dispersion of SO2. This work deals specifically with the use of the Industrial Source Complex Short Term (ISCST) model at a refinery. The study is performed over a period of 21 days. The first objective of this study was to measure the atmospheric levels of SO2 and then to compare their values with the international standard limits. The second objective was to evaluate the ISCST model by comparing the calculated and measured concentrations. The third objective was to demonstrate the effect of wind regimes on the dispersion of SO2 and to determine the spatial distribution of SO2 over the modelled area. The results showed that the levels of SO2 were well below the ambient air quality standard. Based on isopleths for SO2 distribution in the study area (as output from the ISCST model), it can be stated that no health risk is present in areas adjacent to the refinery.