STUDIES ON THE WEATHERING OF MARINE OIL SPILLS

Lamya  Y.  MANSUR

The study of the weathering of oil in the marine environment has been performed using bench scale experiments.

Oil samples were exposed to different laboratory conditions in order to simulate outdoor conditions.

Several analytical techniques were implemented to analyze the original oil and the weathered samples; these included: Capillary Gas Chromatography (CGC), Supercritical Fluid Chromatography (SFC) and Fourier‑Transform Infrared (FTIR) Spectroscopy. The physical properties of the oil were also measured using laboratory instrumentation for the determination of the evaporation loss, water content, viscosity and droplet size of oil samples and water‑in‑oil  emulsions.

Results were interpreted using several statistical and mathematical methods; mathematical algorithms for predicting the weathering of oil spills were also developed and validated, and the model's predictions were used for assessing laboratory results.

The work has proved that laboratory simulation of oil spills can be successfully used for the fingerprinting of crude oils of similar composition and in particular light crude oils which follow identical weathering patterns in oil spills.

The combination of the analytical and interpretation techniques used in this study were capable of detecting minimal and complex changes in oil samples.

Equations for predicting oil weathering were improved and gave close results to those obtained in real oil spills for the exception of the emulsification rates. It was also shown that the physical properties of oil slicks were not possible to reproduce in small‑scale laboratory experiments; only evaporation rates of oil spills were simulated correctly.