Technology plays a major role in cleaning up oil spills. Some methods are booms, skimmers, pumps, and chemical dispersants. Ordinary citizens help by bringing buckets that can be used to clean up the oil. However, most of these methods and types of technology are used in oil spills that occur at sea. None of the modern-day technologies can clean up an oil spill completely without damage to the environment, but they can make a significant difference.
When an oil spill first occurs, a boom is used. A boom is a flotation device which contains the oil so it does not spread. It can be dragged by two vessels or fixated to stay in one spot. Booms are made up of four main parts - a flotation member, a skirt, a tension member, and a ballast member. All of these parts is put together so the oil is kept from spreading and no more damage is caused.
The flotation member is at the top of the boom that is visible above the water. It is usually made out of a flexible material that can self-inflate or be inflated by a pump. The flotation member partly consists of a buoyant foam. Below the flotation member is a skirt that consists of one or two layers of the same material as the rest of the boom. The flexible skirt prevents the oil from escaping below.
A tension member is any part of the boom that goes up and down. It can include the boom fabric and the ballast chain or wire. When the tension member is added with the rest of the boom, it can prevent the wind, waves and current from spreading oil outside of the boom. The ballast member is almost the frame of the boom, or what keeps it together. It is usually made of steel or lead. Some booms have tow bars at the end to attach to a vessel and so that the device can be dragged to pick up oil.
When oil is coming from the mouth of a river or a boat drags it, booms must be placed in a certain angle to the current. This assures that the speed of the water will force the oil into the boom, and not past it. A boom has to be placed so the speed of the water does not exceed 0.7 knots when it hits any part of the boom. There are many different shapes of booms, such as a U-shape, a J-shape, and a V-shape, which are the most common. None of them work perfectly, but aid in cleaning up oil spills.
Two vessels pull each end and the other vessel acts as the skimmer in the middle
The U-shape boom is the most common boom, but does not do a very good job. When it gathers the oil, only a thin layer is created which is hard to pick up by a skimmer. Therefore, it is considered one of the least effective ways of cleaning up oil. It is also hard to maneuver. Usually, two boats are needed to tow the boom and the third is the skimmer.
One vessel pulls the upper part of the J and the vessel that pulls the lower part acts as the skimmer
The J-shaped boom is capable of picking up some oil, but not all. It can be maneuvered effectively by the two vessels. One of the vessels tows the longer end of the J and the other one tows the shorter end. The vessel with the shorter end also acts as a skimmer. It leaves a thin layer of oil which is difficult to be picked up by a skimmer.
One vessel has a pole that branches out from it's side and has a net in the shape of a V. The vessel is equipped with a pump to suck up the oil from inside the boom.
TheV-shape boom is usually smaller than the rest because if it is too big, it would look like and be as efficient as an U-shaped boom. Even though of its small size, a V-shaped boom is very efficient. If a special net on the bottom of the boom is used, oil can be recovered more quickly and efficiently. These are just some of the types of booms.
A skimmer is a device that is used to pick up floating oil from the water's surface. Skimmers are usually used after a boom contains the oil. There are two kinds of skimmers - static and dynamic, dynamic skimmers being the most common. A dynamic skimmer is a unit that moves through the water and can be built into or attached to a boat. If there is an oil spill in a river, a skimmer can be fixated so the water and oil move through it, separating them.
There are many types of skimmers that are used for certain situations. An Adhesion or Oleophilic skimmer works very well because it uses the principle of the oil's ability to stick to certain materials. Some of the good adhesion materials are polypropylene, PVC and aluminum. The oil sticks to a moving surface such as a rotating disc, drum, or brush. Then it is scraped or squeezed off into a bucket or pump.
An air conveying skimmer is like a huge vacuum cleaner. There is a suction hose that is either attached or part of a vessel that sucks up oil. Air conveying skimmers only work if the oil is very light because of the high speed of the air at the end of and inside the suction hose. It just barely lifts the oil off the surface of the water, but is strong enough to carry it to the reception tank. If there wasn't a steady airflow, the vacuum would be ineffective.
Another common type of skimmer is the filter skimmer which has a conveyor belt which picks up the oil. This process is also used in the net-drum skimmer which is made up of a horizontal drum. The drum is made of a metal that stretches and rotates around a circular tube with a built in hopper. It is above the surface so that the oil will be picked up and scraped into the hopper. In the hopper, an Archimedes' screw moves the oil into the transfer pump.
A vortex skimmer is very different than the other skimmers, but works just as well. In the middle of the underside of a vessel there is a large rotating propeller pump or paddle wheel. A vortex is created around the spinning propeller or paddle wheel and the oil is pulled toward it. The oil piles up in the vortex and is sucked up by a pump. These are just some of the common and effective types of skimmers.
When the sea is rough or a boat can't get to the spill, oil spills cannot be cleaned up easily. In this situation, chemical dispersants can be applied to the oil. Chemical dispersants are chemicals that can be applied to oil to make them separate into small droplets to quicken the process of dispersion. Natural dispersion breaks down the oil, but in a very slow process. With the help of chemical dispersants, the process is much quicker so there isn't as much damage.
A dispersant has two main parts, a surfactant and a solvent. The surfactant is a molecule which is composed of two liquids which do not mix. One part has an attraction to oil, which is oleophilic, and the other part has an attraction to water, which is hydrophilic. When dispersants are sprayed onto the oil, the tension combining the two parts is reduced so they become very small droplets of oil. The solvent allows the dispersant to infiltrate into the oil slick. It also acts as a carrier for the surfactant.
Dispersants can be applied to oil spills in quite a few ways. One common way is that they can be sprayed from work boats. This is usually done when it is a small spill. Dispersants can also be applied from airplanes or helicopters. For small spills, small single-engine airplanes or helicopters are used and for larger spills, multi-engine airplanes are used. All planes used are either designed for agriculture or pest control or specially designed planes for the application of chemical dispersants. Some helicopters are specially adopted for spraying chemical dispersants, but most have bucket spray systems.
Some vessels have a set of nozzles that spray the dispersants attached to booms. The nozzles are put far forward, so that when the boat moves, the dispersants will be applied to the oil. Also, the bow wave helps mix them so the dispersants can do their job. Vessels can have portable of permanently installed spray modules. Large droplets, rather than a fog or mist, are sprayed so they do not get carried away by the wind to an unneeded location.
Bioremediation, which is another clean up method used, is the application of chemical fertilizers. The fertilizers are nutrient materials that quicken the process of biodegradation, which is the natural process in which bacteria and other organisms break down the oil. When nutrients, such as phosphorous and nitrogen are added, bacterial growth can take place. These organisms break down most of the oil, or "eat" it. Bioremediation is mostly applied to beaches.
The History of the Technology
The technology that is used to clean up oil spills was not invented too long ago. Oil spills, which are many times of the result of human error started to occur in of the 20th century because of the increase in the need for oil. One of the easiest ways to transport the oil was by sea. To meet the new and sudden large demand of oil, more and more ships started transporting it which then created a higher risk of oil spills. Currently more accidents are occurring which means we need more efficient ways of cleaning them up.
In the 1950's and 60's, common and easy methods were used to clean them up. Crews from organizations and volunteers would clean up most of the spills by using buckets, shovels, and wheelbarrows. This technique was used for a while, but it was soon discovered that the method was not that effective.
Chemical dispersants were first created a little over 20 years ago. They are supposed to clean oil spills well, which they do. But, they are toxic and harmful to animals and plants. Some people thought that they are more harmful than useful, so now they aren't used as much. However, some of the present day chemical dispersants are safer. Scientists are still trying to improve them so there is no harm done, just good.
Limitations and Benefits
- can't be used in rough weather
- can't be used too close to rocky shore
- could trap marine life
- the different chemicals used to make the boom could run into the water
- nets could get caught on something and could tear, letting the oil out
- small organisms can be harmed by the disruption in the water
- the food chain is disrupted
- traps the oil so it can be picked up by skimmers
- inflatable booms can be stored easily
- non flammable
- easily maneuvered
- can't pick up all the oil
- not easy to use
- can't go near the shore
- can pick most of the oil
- can go inside booms
- can be removed from a vessel
- they harm animals
- they harm plants
- too many chemicals can pollute water
- too many toxics
- people can eat the infected seafood
- people can be harmed when they are scuba diving
- breaks up most of the oil so it can dissolve
- can be sprayed by a plane - can be a faster clean up
- can be a more efficient clean up
- the micoorganisims can harm smaller and more sensitive life forms
- the eliminating of the oil will vary because of temperature, moisture, and chemical characteristics
- it will not thoroughly clean up metals and chlorine compounds
- the small microorganisms clean oil spills more efficiently than any other technology today
- it biodegrades the petroleum hydrocarbons
- biormedation is very flexible and can be used with other technologies
Why It's a National Critical Technology:
There are many technologies that help clean up oil spills. One technology application is booms. A boom is a technology that contains oil. There are many types of booms. One, for example, is called that Slickbar boom. It contains oil by providing barrier in shoreline areas where there are calm seas. It can also be connected with other types of booms. This makes a complete boom system to provide good coverage around environmentally sensitive marinas. Booms are very important in the clean up process for oil spills.
Another technology that is critical for cleaning up oil is skimmers. Skimmers are like giant vacuum cleaners that on boats. Skimmers are very effective when cleaning up oil spills. They suck up the oil and separate the oil from the water. There are also many types of skimmers. Some are more effective than others are.
Another technology that is used is chemical dispersants. Natural dispersion of an oil spill can occur when waves and other agitation in the ocean surface cause the oil to break up into droplets and enter into a water column. Chemical dispersants speed up this process. The interfering tension between the oil and the water is reduced when chemical dispersants are sprayed onto and oil and oil slick. This causes the oil to break up into fine diffused oil droplets. Chemical dispersants aren't effective all the time. When there is thick, floating oil, the dispersants usually run off the oil into the water before the chemical solution can sink in. This is why other solutions are needed.
Bioremediation is another critical technology. Bioremediation is a microbiological treatment for environments that is made up of varieties of organic and inorganic compounds. It purposely conducts microorganisms to consume and break up pollutants. It is one of the most effective solutions to come around in the 20th century! It is very critical in cleaning up oil spills.
Each on of the National Critical technologies we selected is very, very important to the earth's ecosystem and economy. Oil spills can harm the earth very badly by killing a lot of animals and take money out of the nation's economy. If we didnt have any of these technologies many species of animals could have been killed off and a big chunk of money could have been cut out of the world's economy. Each technology is very important.
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