IMPACT OF PAH OUTLETS FROM AN OIL REFINERY ON THE RECEIVING WATER AREA - SEDIMENT TRAP FLUXES AND MULTIVARIATE STATISTICAL-ANALYSIS

PAH concentrations (15 compounds) in settling particulate matter (SPM) collected in the waters outside a petroleum refinery on the Swedish B altic coast, and in samples of particulate and dissolved fractions in the wastewater from the refinery were determined. SPM concentrations v aried between 550 and 4250 ng x gdw(-1) and the corresponding calculat ed fluxes varied between 0.1 and 3.7 ng x cm(-2) x day(-1). Both conce ntrations and fluxes did not differ significantly from background coas tal or offshore locations in the Baltic, PAH profiles of the SPM sampl es were compared with the wastewater samples and SPM samples from back ground areas in the Baltic, using pattern recognition techniques. This analysis showed that the SPM samples from the petroleum refinery disp layed a PAH composition similar to that found in background reference sites in the Baltic, and that the SPM samples could not be connected t o the wastewater samples from the refinery. This indicates that Nynas AB is not a significant source of PAHs to the waters in its immediate surroundings, i.e. the waters in the Nynashamn area, and/or that the h ydraulic residence time of the water outside the refinery is low, A bu dget calculation showed that the wastewater outlet from Nynas AB is on ly a minor contributor of the PAH load to the waters outside the refin ery. (C) 1997 Elsevier Science Ltd.