What Cleans Up Oil Spills?

Although the exact method used to clean up an oil spill depends on the type of oil, the location of the oil and the size and scale of the cleanup operation given the circumstances, there are approximately four different ways to do so. Each should be considered in turn before any action is taken to be sure of achieving the most effective outcome.

Natural Breakdown

• One way to clear an oil spill is to leave it alone. This only works when there is no chance that the stray oil will pollute the coast or cause damage to marine wildlife, and unfortunately that is a rare outcome. If left alone, the oil disperses naturally until it no longer poses a threat. Waves, wind and sunshine all help to break the oil down and help it to evaporate, unless it is a particularly heavy oil, which will not submit to natural pressures.

Skimming

• A purely physical method, skimming involves isolating the oil spill with large, floating booms and then lifting it from the surface of the water or coastal area using skimmer equipment. Because oil is so thick and sticky, it clings to rocks and even the surface of the sea in one long, dense layer and can be separated mechanically by the skimming process. Booms are also used to block the progress of newly spilt oil into uncontaminated locations, which can help protect nearby animals.

Assisted Dispersion

• The assisted dispersion method is a development of the natural breakdown method. Dispersants are added to the spilt oil to assist and speed up the process of dispersion that would naturally occur given time, but which might not be fast enough in certain circumstances. If plants, animals and people are at risk, the oil spill has to be tackled actively rather than passively. Assisted dispersion compounds (usually salt species) act in a similar way to bile salts in our digestive tract, breaking the oils and fats down into smaller quantities, which can then be dealt with more easily.

Biodegradation

• This method involves the addition of biological agents, such as oil-eating bacteria, to the oil to digest it. The bacteria consume and process the oil and produce several byproducts, mainly harmless fatty acid compounds and gaseous carbon dioxide, which floats up into the atmosphere and can be reused during harmless processes. (Plants use carbon dioxide to synthesize proteins.) An additional step in this process is needed: nitrogen and phosphorus are added to the bacteria to speed their digestion up and stimulate their multiplication. The result: more oil gets degraded faster.

New Technologies

• The key to clearing an oil disaster is to plan for one. There's never enough time to sit and talk about new technologies when the spill has already happened, as a single failure in the oil-mining machinery can release over two million gallons of oil, according to In Habitat. One idea, proposed by engineers working for British Petroleum (BP), is to build a huge dome that can sit on the oil spill and contain it and even transport it to a safe zone where it can be dealt with. Another method, trialed in 2007, was to soak the oil up with organic mops made of mushrooms and hair. Chemical herders are a third new invention -- low toxicity chemicals added to the oil, which do not disperse it, but collect it into a more manageable state. It can then be skimmed quicker.