1. Collection of oil and its containment over a specific area, using booms.
Containment can also be achieved by use of oleic or stearic acid which spread rapidly over the water surface, pushing back the oil. 2. Sinking can be effected by such agents as gypsum, carbonized sand, or stearate-coated chalk. However, this method is not good since the sunken oil may affect benthic organisms and also its biodegradation may be greatly decreased. 3. Dispersing of the oil slick by using various anionic and non-anionic dispersants.
4. Burning can be resorted to if the spillage has occurred away from seashore. Burning is effective only if the slick is ignited immediately after a spillage.
Delay causes evaporation of volatile compounds, leaving a residue that is hard to ignite. 5. Stimulate biodegradation is a very good method. It is based on supplementing the seawater with nitrogen and phosphates (which are limiting) or some other limiting factor, and then seeding some suitable oil-degrading microbes. The microbes used either include a single species or a mixture of different species, or an artificially created or genetically engineered “superbug”. This method is especially useful in treating that portion of spill oil that has escaped the primary physical containment, or in treating effluents with such low oil content that physical purification is either not feasible or uneconomic (Atlas and Bartha, 1973).