Transport and behavior of marine oil spill containing polycyclic aromatic hydrocarbons in mesocosm experiments

Polycyclic aromatic hydrocarbons (PAHs) are one of the most important groups in oil, and responsible for major toxic and/or carcinogenic impact on humans and wildlife. It is important to understand the behavior of PAHs in marine environment after an oil-spill incident. However, interaction between petroleum PAHs and microbial communities in a marine environment remains unclear. Therefore, a series of mesocosm experiments were conducted, in which water-accommodated fraction (WAF) of oil was generated to simulate an oil-spill scenario and to analyze the transport and behavior of marine oil spill containing PAHs with and without dispersants. Results indicate that the application of dispersant could increase the concentration of total PAHs in water column due mainly to significant increase in the concentration of high-molecular weight (HMW) PAHs at a lower removal rate. At the end of the 7-day experiment, significant amount of HMW PAHs were accumulated in sediment. In general, the application of dispersant did not increase the sediment uptake of PAHs but increased the PAHs concentration in water column.