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.