Oil slicks

Regardless of the source, the resultant oil slicks are essentially surface phenomena that are affected by several transportation and transformation processes.With respect to transportation, the principal agent for the movement of slicks is the wind, but length scales are important. Whereas small weather systems, such as thunderstorms, tend to disperse the slick, cyclonic systems can move the slick essentially intact. Waves and currents also affect the advection of an oil slick. To a more limited extent, diffusion can act to transport the oil. 

The discussion above focuses on petroleum hydrocarbons from oil spills, representing just one source of contamination. Marine contaminant surveys are conducted not just in response to tanker accidents, but routinely as a means to assess the quality of the marine environment. Although analytical difficulties with environmental samples persist and 

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Contemporary concern about pollution has made it important to dispose of oil slicks from spiUs. The suitable use of surfactants may reverse the spreading of the slick, thereby concentrating the slick for easier removal. 

Oil Shale Trust Fund Oil slick Oil slicks Oil spills... 

To remove fats, oils, and grease from our clothes, our hair, our bodies, and our dishes, we use products known as surfactants. These contain ingredients that make oil and water mix, forming tiny droplets out of oil slicks, so the droplets can be washed away in the rinse water. 

Oil Slicks and Floating Tar. About 100,000 visual observations of the sea surface made between 1974 and 1978 (9, 10) demonstrated that oil slicks were closely associated with the tanker routes from the Middle East through the Suez Canal and around the Cape of Good Hope to Europe, from the Middle East to Japan, and to a lesser extent, along the transatlantic and transpacific shipping lanes. Outside these areas, slicks... 

Dispersants are widely used in many parts of the world to deal with oil spills on the ocean. The objective of adding the dispersant is to emulsify the oil slick... 

Modem oil spill-dispersant formulations are concentrated blends of surface-active agents (surfactants) in a solvent carrier system. Surfactants are effective for lowering the interfacial tension of the oil slick and promoting and stabilizing oil-in-water dispersions. The solvent system has two key functions (1) to reduce the viscosity of the surfactant blend to allow efficient dispersant application and (2) to promote mixing and diffusion of the surfactant blend into the oil film [601]. 

A. Charlier. Dispersant compositions for treating oil slicks on the surface of water (compositions dispersantes pour le traitement de nappes d huile a la surface de I eau). Patent EP 254704, 1988. 

A. Charlier. Dispersant compositions for treating oil slicks on cold water. Patent EP 398860, 1990. 

In addition to their role in chemical defense, DMSP-lyase products may also function as chemical cue in more complex trophic cascades. In the natural environment DMS-production is related to zooplankton herbivory [60] and can thus act as an indicator for the availability of food for planktivorous birds. Indeed, some Antarctic Procellariiform seabirds can detect DMS (22) and are highly attracted to the cue, as was shown with DMS-scented oil slicks on the ocean surface [61]. The odors released during zooplankton grazing (DMS) as well as those of zooplankton itself (e.g., trimethylamine and pyrazines) are attractive to birds [62], thus assisting vertebrate search behavior. 

Pierre [60] has reported a study of the characterisation of the surface of oil slicks by infrared reflective spectroscopy. A double-beam spectrophotometer was modified for studying the reflectance spectra (at angles of incidence 45°, 60°, 70°) of oil layers (20-30 xm thick) on the surface of water using pure water as reference. 

As oil enters the environment, it begins to spread immediately. The viscosity of the oil, its pour point, and the ambient temperature will determine how rapidly the oil will spread, but light oils typically spread more rapidly than heavy oils. The rate of spreading and ultimate thickness of the oil slick will affect the rates of the other weathering processes. For example, discharges that occur in geographically contained areas (such as a pond or slow-moving stream) will evaporate more slowly than if the oil were allowed to spread. Most of this process occurs within the first week after the spill. 

The weathering of a crude oil slick at sea. Source-. From Preston, M. R. (1988). Chemical Oceanography, Vol. 9, Aoademic Press, pp. 53-96. 

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