Friday, March 14, 2008

Oil Spill by Megan Silva



An oil spill is the release of a Liquid petroluem hydrocarbon into the environment due to human activity, and is a form of pollution. The term often refers to marine oil spills, where oil is released into the ocean or coastal waters. The oil may be a variety of materials, including crude oil, refined petroleum products (such as gasoline or diesel fuel). Spills take months or even years to clean up.

Studies of the Exxon Valdez Oil Spills have shown that the environmental damage caused by oil spills can be greater than was previously thought. Petroleum-based hydrocarbons can negatively impact marine life at concentrations as low as one part per billion.

Seabirds are severely affected by spills. The oil penetrates and opens up the structure of their plumage, reducing its insulating ability, and so making the birds more vulnerable to temperature fluctuations and much less buoyant in the water. It also impairs birds' flight abilities, making it difficult or impossible to forage and escape from predators. As they attempt to preen, birds typically ingest oil that coats their feathers, causing kidney damage, altered liverdigestive tract irritation. This and the limited foraging ability quickly causes dehydration and metabolic imbalances. Most birds affected by an oil spill die unless there is human intervention. function, and

Marine mammals exposed to oil spills are affected in similar ways as seabirds. Oil coats the fur of sea otters and seals, reducing its insulation abilities and leading to body temperaturehypothermia. Ingestion of the oil causes dehydration and impaired digestion. fluctuations and

A sheen is usually dispersed (but not cleaned up) with detergents which makes oil settle to the bottom. Oils that are denser than water, such as Polychlorinated Biphenyls (PCBs), can be more difficult to clean as they make the seabed toxic.

Clean-up efforts after Exxon Valdez oil spill.
Experiencing Oil Spills makes an economic crisis,for the reason, that we will be having a hard time removing all the oil. And by this, instead of earning more money for our country, we are obligated to pay a high maintenance machine to suck it all, and worse, the people who are living near it will be having a hard time looking for a new diverse job to earn money for there family.

Here are the methods that we have to do to clean up the oil spills


Methods for cleaning up include:

  • Bioremendation: use of microorganisms or biological agents to break down or remove oil
  • Controlled burning can effectively reduce the amount of oil in water, if done properly. But it can only be done in low wind, and can cause air pollution.
  • Dispersants act as detergents, clustering around oil globules and allowing them to be carried away in the water. This improves the surface aesthetically, and mobilises the oil. Smaller oil droplets, scattered by currents, may cause less harm and may degrade more easily. But the dispersed oil droplets infiltrate into deeper water and can lethally contaminate coral. Recent research indicates that some dispersants too are toxic to corals.
  • Watch and wait: in some cases, nautural attentuation of oil may be most appropriate, due to the invasive nature of facilitated methods of remediation, particularly in ecologically sensitive areas.
  • Dredging: for oils dispersed with detergents and other oils denser than water.
  • Skimmers: Requires calm waters

Equipment used includes:

  • Booms: large floating barriers that round up oil and lift the oil off the water
  • Skimmers: skim the oil
  • Sorbents: large sponges that absorb oil
  • Chemical and biological agents: helps to break down the oil
  • Vacuums: remove oil from beaches and water surface
  • Shovels and other road equipments: typically used to clean up oil on beaches

Prevention

  • Secondary containment - methods to prevent releases of oil or hydrocarbons into environment.
  • Oil Spill Prevention Containment and Countermeasures (SPCC) program by the United States Environmental Protection Agency.
  • Double hulling - build double hulls into vessels, which reduces the risk and severity of a spill in case of a collision or grounding. Existing single-hull vessels can also be rebuilt to have a double hull.




MeGaN AiShA