Monitoring and analysis of volatile organic compounds around an oil refinery

Valle Galeria, a location in the outskirts of Rome, was selected as a case study to assess the pollution release from the industrial facilities operating in this area. For this purpose, an intensive field campaignwas conducted during summer, where volatile organic compoundsVOC(including benzene, toluene and xylenes) were sampled and analyzed at two different sites. A strong modulation of VOC concentrations was observed between daytime and nighttime, and alkane fraction was found to be the most abundant group, indicating the oil refinery as the major source of atmospheric hydrocarbons. Surface turbulence and upper air SODAR data were processed to investigate the relationships between meteorology andVOC levels and patterns. Atmospheric turbulencewas found to be responsible for the daily modulation of VOC. In particular, the highest BTX pollution episode observed during nighttime was found to be correlated with a very strong atmospheric stability and a surface based inversion layer. The analysis of BTX ratios resulted effective in recognizing the relationship between the pollutants and their co-variance, as well as the dispersion and reaction patterns occurring during the transport across the two sites.