Fluorescence properties of mechanically dispersed crude oil

Despite of numerous actions undertook by the global and local authorities towards protection of marine environment, oil pollution loads into the Baltic Sea still tend to increase and need to be continuously estimated in order to apply the legal regulations. There is a demand for multifarious studies on the environmental effects of oil products. Dispersed oil droplets occur in seawater as the result of contaminated river inflows, bilge water discharges and as the consequence of mechanical and chemical dispersion of oil spills. Their optical properties depend on oil type, concentration and size distribution. Oil content influences many environmental factors, like water quality and bio-optical parameters (e.g. water-leaving radiance, inherent optical properties, seawater fluorescence). We present a unique study of the collected database of crude oil fluorescence spectra for better understanding the correlations between oil optical properties and its concentration, as well as for evaluation of the oil droplets size by the application of vacuum filtering using three filters of different permeability. Fluorescence spectra have been registered for oil-in-water emulsion samples prepared in the laboratory by mechanical dispersion. We discuss the optical properties of crude oil and the relationships between them in the context of potential remote detection of dispersed oil in seawater.