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What Is Used to Clean Up Oil Spills in Water?

Oil spills were a huge concern in the early 1990s, when 240 million gallons of oil spilled from terminals and tankers in the Persian Gulf. In April 2010, the Deepwater Horizon oil spill reminded people of these dangers, when an underwater explosion released 206 million gallons of crude oil into the Gulf of Mexico. The cleanup operation was extensive, employing a number of techniques.

  1. Containment and Skimming

    • Oil and water do not mix, which is fortunate when it comes to cleaning up. Instead oil forms a coat on top of water, about 0.01 millimeters thick. Even the largest oil spill eventually expands out across the ocean until this is the case. If emergency workers can reach the spill quickly, the quickest solution may just be to skim the oil off the surface. Long, buoyant booms are placed in the water. The booms float and contain the spill with a skirt that hangs down to prevent any oil escaping. About 2,500 miles of these booms were used during the Deepwater Horizon spill. The oil was skimmed off the surface by boats that suck or scoop up the oil. If the crew arrives too late, the oil will spread over a far larger area.

    Sorbents

    • Large sponges called sorbents also may be used for an isolated slick. These sponges are made of a similar material to a baby's diaper and absorb the oil off the surface of the water. Other materials used can include straw, grasses, coconut husks or wood chips.

    In Situ Burning

    • Setting fire to the oil is one of the most effective ways of dispersing oil, usually dealing with 95 to 98 percent of the slick. As with burning any other substance, the process results in a thick, black smoke that in this case is toxic and is to be avoided if a slick takes place near coastal towns. A slick far out at sea would usually be treated in this way.

    Do Nothing

    • It may seem strange, but leaving an oil slick is sometimes the most efficient way of dealing with it. A highly dispersed slick that is difficult to skim eventually will be broken down by oil-eating bacteria in the water. This process can be sped up with dispersants that break the oil into tiny, more edible, droplets. The motion of the waves and photooxidation from the sun also help to break down oil in this way.

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