Review Paper: Oil Spill Dispersants
Abstract
Oil dispersants are one of the methods used to clean up oil spill. They are capable of rapidly removing large amount of certain oil types from the sea surface by transferring it into the water column. They enhance oil degradation in the environment. Oil dispersant is a chemical mixture of surfactants and solvents that helps break up oil into small droplets following an oil spill. Because dispersants help to degrade oil and make it to sink into the water rather than removing it from water, they are so controversial. Consequently, the uses of dispersant are limited to spill that occurred at least five kilometers from the shoreline and in water at least 10 meters deep. The use of dispersants involve
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Oil dispersant is a chemical mixture of surfactants and solvents that helps break up oil into small droplets following an oil spill. Similarly to the way soaps or detergent work, dispersants break up large oil slicks lying on the top of water into smaller manageable particles (Pam, 2010). Dispersants are primarily composed of solvent and surfactants. The role of solvents is to reduce the viscosity of surfactants in order to be easily sprayed. In addition, solvents promote the penetration of the surfactants into the oil slick. On the hand, surfactants are surface active agents that are used to reduce surface tension between water and oil so as to increase wettability. The effectiveness of oil dispersants depends on the hydrophilic-lipophilic balance (HLB) –which is a coding scale from 0, to 20. A zero value corresponds to the most lipophilic and a value of 20 is the most hydrophilic. Oil dispersants usually have HLB values from 8–18 (G.P.Lindblom, …show more content…
Due to lack of technical know-how and equipment to spray the chemicals, the first few applications of dispersants were ineffective. Because dispersants help to degrade oil and make it to sink into the water rather than removing oil from water, the use of dispersant are limited to spill that occurred at least five kilometers from the shoreline and in water at least 10 meters deep where there is a low impact of dispersant on marine life (Kearney, 2016). For example in the United Kingdom, dispersants cannot be used in water less than 20 m deep without the permission of Environment Food and Rural Affairs department (Alan & et al,
Normally, emulsified water is generally present in crude oil as a result of the mixing occurring during production operations and referred to as oil field emulsion. This emulsion can be encountered at numerous stages include during drilling, producing, transporting and processing of crude oil. However, the formation of emulsion creates problems in oil field industry. They might increase the cost of production and also transportation; accumulate in the refinery tank age, pipeline corrosion, equipment failure, plugged pipeline. For economic and operational reasons, it is necessary to remove water completely from the crude oil emulsion before refining and transporting those. In order to separate the water content of the produced crude oils, the emulsions have to be broken through demulsification process.
The Deepwater Horizon spill occurred on 20 April 2010 and was caused by an explosion on the Deepwater Horizon drilling rig that killed 11 workers and injured 17 more. The drilling rig, located 66 kilometers southeast of the Louisiana coast, left an oil gusher that was finally capped on July 15, almost 2 months later. This was the largest accidental marine oil spill in history and the largest offshore environmental disaster in the United States (Telegraph, New York Times, BBC News). It is estimated by scientists that over 4.9 million barrels of oil were released into the ocean, about half of the crude oil the U.S. imports each day and worth $400 million (Popular Mechanics, CBC News). About 1070 kilometers of coastline were contaminated. Over 47 thousand personnel were deployed, 1.4 million barrels of liquid waste collected, and $40 billion spent on cleanup.
Jackson, Lisa P. (24 May 2010). "Statement by EPA Administrator Lisa P. Jackson from Press Conference on Dispersant Use in the Gulf of Mexico with U.S. Coast Guard Rear Admiral Landry"
This oil as it moved through the water killed 300,000 sea birds, 2,600 sea otters, 300 harbor seals, and perhaps millions and millions of fish. Of the 23 studied species hurt by the spill only 2 are said to be completely recovered. The 2 are the Bald Eagle and the River Otter. Some show no recovery at all. Of these that haven’t recovered at all are the Harbor Seal, Harlequin Ducks, Pacific Herring, Cormorants, and even certain whales. If people were familiar with some of the clean up that went on, they would probably remember that cleaning of all those ducks. Well I hate to tell you but it was useless. Some of them died 5 days after they were released.
One particular article mentions that there are two types of spills: shore-bound surface spills and the deep-ocean oil spills. Surface oil spills are more detrimental to the health of species that occupy that space, such as seabirds. In addition, organisms within shallow waters are affected by the oil spills. These include salt-marshes and mangroves (Peterson et. al 2012). Oil itself is conventional or unconventional depending on the quality of the oil. Conventional oil is light and flows underground from reservoirs easily. Unconventional oil is heavy and thick, making it less desirable for use (Hirsch et. al 2005).
To control the oil, they used floating bombs to break the chemical and surface oil down. Many scientists and researchers collected data by looking into details about the Gulf region. There was a big impact on the Gulf coast, marine life, and human communities that some researchers and scientist are still trying to figure out. It is very difficult to clean oil out of the ocean, especially when it’s 3.19 million barrels. There were two different types of oils that were spread in the ocean. What affects how the oil spills is the amount and type.
When the oil spilled into the ocean, it spread out on the water surface very rapidly to form a thin layer of oil which is known as oil slick. The split oil will cause several impacts to the beaches, habitat and wildlife. When the oil spills reaches the beach, it will cling to the sand and rocks together and eventually they clump together which will poison the beach. When the spilt oil washes the mangrove swamp or other wetlands, the fibrous plants will absorb the oil which can damage the plant
Bioremediation uses bacteria and fungi to break down oil. Nitrates or fertilizers are added to the spill to provide nutrients to quicken the growth of the bacteria and fungi.
Oil is one of the most common water pollutants in the world, primarily because of how much is used on a daily basis (National Research Council, 2014). Spills, leaks and improper disposal lead to oil seeping into our water supply and contaminating it. According to Gale (2008), Oil spills are created by the accidental or intentional release of crude oil (petroleum). When spilled into rivers, streams, or marine environments, oil can damage ecosystems far from the original spill areas. Even though the oil spill is cleaned and the water is decontaminated, the petroleum leaves behind residues of relatively heavy molecules that are more persistent in terrestrial or aquatic habitats, and cause longer-lasting effects. In addition to cost to repair and clean, oil spills can result to economic lost and long term economic damage to the affected areas.
It only takes one small mistake, and we’re dealing with oil spills. Oil spills can occur both on land, and in the marine environment, but this paper is going to specifically focus on the harm of marine oil spills. The largest United States marine oil spill took place in April of 2010, lasting until July of 2010 in the Gulf of Mexico. This explosion became known as the Deepwater Horizon oil spill (or the BP oil spill), and it amounted to up to 9,000 barrels of oil filling our ocean and harming the ocean wildlife (Sylves and Comfort, 84). Also taking the lives of 11 rig workers and injuring 17, this explosion has been called “the worst environmental disaster in US history.” According to Drew Griffin, Nelli Black, and Curt Devine of CNN, “For 87 straight days, oil and methane gas spewed from an uncapped wellhead, 1 mile below the surface of the ocean.” One can only imagine how the many species of the ocean were harmed during this
Oil spills usually have only a limited effect on the environment but can spread for miles. The oil can cause the death of many fish and can be attached to the feathers of seabirds which lead to loss of their ability to fly.
Oil Spills disturb the environment and produce a threat to the animals living in that area. Both ships and refineries release oil into the rivers and oceans which leads to the damage and death of plants and animals (Leggett 25). Exxon Valdez, a famous tanker that split in Alaska, spilled eleven million gallons of crude oil into the oceans, damaging everything around it (Earle 145). A Deepwater Horizon oil rig exploded and released sixty thousand barrels of oil each day (Hollar 20). World War II ships exploded bombs and released diesel fuel which turned beaches black for months. Moreover, oil engulfs plants and blocks the sunlight from nourishing them. It also smothers animals, suffocating them with a painful death (Leggett 24). Sea otters and seabirds are two of the main animals affected by oil spills (Earle 146). Animals such as deer, bears, and bald eagles died a much slower death because they eat the animals from beaches that were covered in oil (Leggett 39). If humans do not clean up the spilled oil right away, it mixes with the water and becomes much harder to eliminate from the sea (39). Furthermore, oil spills
According to the article, “Beyond Catastrophic Oil Spills: Pollution In Our Oceans,” about 25 gallons of North America’s daily oil runoff is from our daily use. In particular, the oil going into our oceans affects marine life, humans, and the health of the ocean. In contrast, some people may argue they need the oil to run our cars and to do other things. But, do they really need to? Oil dumping and oil pollution should be prohibited around the world.
The importance of reusing and adequately dispensing oil has increased in many communities (“Oil Pollution”). Therefore, if enough people take the extra time to reuse or collect the oil, the change in the ocean would be enormous. Not only is this for the health of the ocean, but also for the health of the population. Of course, people use oil for their everyday lives, but there are healthier alternatives to their needs. For each person “an average oil change uses five quarts,” and this “one change can contaminate a million gallons of fresh water” (“Oil Pollution”). The harm caused by oil is problematic because once the oil reaches water, the water remains contaminated. Animals suffer from slow and painful deaths because oil seeps into their gills stopping their breathing causing slow suffocation. Harming the fish will affect the sustainability of
They can be easily differentiated visually. The main focus of the present work is water-in-oil emulsions which appear as dirty oily water. They can contain different oil types and in various concentrations. Depending on the industry fats, cutting fluids, lubricants, tars, crude oils and grease can be found. In order to extract them from water hexane, carbon tetrachloride, fluocarbons or chloroform can be used. Apart from the oil, various contaminants can be present in emulsions such as solids, metal particles, soaps, silt and