There are various methods for cleaning up oil spills. Some methods allow oil to be recovered, whereas others do not. Some methods are more expensive than others, some are more efficient than others, and some have more of an environmental impact. Regardless of the method used, cleaning up oil spilled on water is a very time-consuming and difficult task. In this activity, you will model various methods used for cleaning up an oil spill on water. Material and Equipment:
3 container for the oil-and-water mixture (such as soup bowls) Graduated cylinder or measuring cup
Medicine Dropper (Skimmer)
Plastic Cup (Oil Tank)
Shredded paper towel (Sorbent)
Powdered and/or liquid detergent (Dispersant)
Which method is the most efficient in cleaning up an oil spill on water? I think that the Skimmer is the most efficient because it is able to recover most of the oil in a reasonable amount of time. Skimmers also have minimal interference with the marine environment whereas Sorbents can sink which causes harm to the marine environment. Dispersants are also not effective since they break down the oil which later sinks down to the bottom of the ocean causing harm to the deep sea environment which is where many of marine life is found, it also uses chemicals that are harmful to the environment.
1. Copy the following chart
Shredded paper and spoon
Detergent and spoon
1. Using the graduated cylinder, add 80 mL of water to each of the three containers. 2. Using the graduated cylinder, measure 5mL of vegetable oil. Slowly pour the oil into the first container so that the surface of the water is covered. Repeat the process for the other two containers. Clean up any oil or water that you spill. 3. To clean up the “oil spill” use the skimmer (medicine dropper), sorbents (shredded paper), and a dispersant (powdered and/or liquid detergent). Remove as much oil from the oil-and-water mixture. Observe which method works most quickly and recovers the most oil and record all observations in the table. 4. After finishing the following procedures, rank each method from 1 to 3, 1 being the most efficient and 3 being the least efficient.
1. Skimmer- Using the medicine dropper as a skimmer, collect the oil from the surface of one of the container. 2. Pour the collected oil inside the dropper inside the oil tank (plastic cup). 3. Repeat step 1 and 2 until you have collected as much oil as possible. Sorbents
1. Tear the paper towel into smaller pieces.
2. Scatter the sorbents (small pieces of the paper towel) onto the surface of the water in the second container. 3. Wait till the sorbents (small pieces of the paper towel) have absorbed as much oil as it can. 4. Use the spoon in order to recover all the sorbents (small pieces of the paper towel) from the container. 5. Place the sorbents (small pieces of the paper towel) onto the oil tank (plastic cup) 6. Repeat steps 2 to 5 until you have removed as much oil as possible. Dispersants
1. Pour a spoonful of detergent into the third container.
2. Wait for a few minutes for the detergent to do its work.
3. Collect the oil with the spoon until you have collected as much oil as possible.
The skimmer broke up the oil into smaller blobs.
It removed significantly more water than oil.
It took a much longer time to remove the oil
Shredded paper and spoon
Absorbed a lot of water along with the oil however, a significant amount of oil was left on the surface of the water. The Sorbents sunk down to the bottom of the container.
Detergent and spoon
Detergent sunk down and then broke the oil into smaller blobs. It took a long time before the detergent had any effect.
Took about 15 minutes for the oil to sink down to the bottom of the container. 3
Analyzing and Interpreting
1. When you slowly poured the oil onto the water, did it float or sink? Explain your observation in terms of density. a. When the oil was poured onto the water of each container, the oil floated. This is due to the fact that, any substance that has a lower density than the other fluid, the substance will float. In this case, oil has a density of 0.88g/cm3 whereas water has density of 1g/cm3 which means the oil will float atop of the water because it has a lower density than water. 2. Which of the three methods do you think would have the least impact on the environment? Explain. a. The skimmer was able to recover almost all the oil with the least impact to the environment. However, it also removed a lot of water from the container and took much longer than the other methods. On the other hand, Dispersants made it much easier to remove the oil with the spoon but it introduced harmful chemicals into the environment which could have had devastating effects on the environment. The Sorbents were also very ineffective because it did not remove sufficient amount of oil and also sank to the bottom which could result in the death of many sea creatures mainly because there isn’t really a “giant spoon” to remove the sorbents from the ocean in real life situations, this goes the same to Dispersants, because the small oil blobs had to be removed manually by using the spoon. 3. If a strong wind was blowing and the surface of the water was rough, which method do you think would the best? Explain. a. Using Dispersant would be the best method because it will break down the oil into smaller blobs which will than sink down to the bottom. Although this may have a negative effect on the environment, it will still remove the oil from the surface of the water. On the other hand, using sorbents will not remove sufficient amount of oil and may have a negative environmental effect. Using Skimmers will also be ineffective since they only work on calm waters.
4. Was cleaning up your oil spill more difficult or easier than you thought it would be? Explain. a. It was much harder than I thought it would be because we had to wait for some of the effects to happen to the oil-and-water mixture for some methods. We also realized that we had to be more careful and precise.
1. In Science, it is often useful to use numbers or measurements when comparing different methods. Suppose you wanted to take a measurement so that you could compare the three methods. Explain what measurement you would take and how you would change the procedure to collect the measurement. In order to compare the three methods, I would use millilitres as my unit of measurement. However, the current procedure has many flaws that make the results very inaccurate and unreliable. In order to fix these flaws, I would first have three separate graduate cylinders for each one of the containers. Than the following changes would be made: i. Skimmer: after the medicine dropper sucks in the oil and the water from the container, wait a few minutes so as the oil and the water can separate leaving the water in the bottom. Then, push the medicine dropper so as all the water in the bottom of the dropper is released into the container, leaving only the oil inside which will be placed inside the first graduate cylinder. Then, continue the process until you have removed as much oil as possible. Then, measure the removed oil in the graduate cylinder and record it. ii. Dispersants: since the dispersants sinks the oil to the bottom of the container after about 15 minutes. Use a Separation funnel instead of a container. Then, wait till all the oil has sunk down to the bottom of the funnel. Then, separate the water at the bottom of the funnel and pour the oil into the second graduate cylinder. Then, measure the recovered oil and record it. iii. Sorbents: after finishing the procedure for sorbents listed above, pour the oil-and –water mixture into a Separation funnel. Then, wait till all the oil has sunk down to the bottom of the funnel. Then, separate the water at the bottom of the funnel and pour the oil into the third graduate cylinder. Then subtract the amount of leftover oil from the original amount of oil which was 5mL in order to find out the amount of oil that was absorbed by the sorbents then record it. b. Finally compare all the recovered oil through the different methods. Forming conclusions
1. Two factors that determine the efficiency of the clean-up method are how quickly the oil was cleaned up and the amount of oil that was cleaned up. Using these two factors, explain which method you believed was the most efficient. a. Skimmers : I think that Skimmer was the most efficient because of the following: The Time Factor
The Amount of Oil recovered
Took a bit more than the reasonable amount of time because we had to be more careful. It also took longer at the end because the oil broke up in smaller blobs. It recovered most of the oil. However, it also removed a lot of water which left us with about half of what we had at the end of the experiment. It also had the least impact on the environment b. Dispersant
The Time Factor
The Amount of oil recovered
It took about 2 to 4 minutes for the oil to break up into smaller blobs and took about 15 to 20 minutes for the oil to sink down to the bottom of the container. Most of the oil was recovered, however, large amounts of water was also removed. It was almost impossible to recover the oil from the bottom of the container unless we use a Separation funnel.
The Time Factor
The Amount of oil recovered
The paper towels absorbed as much water as it was able to right after it came in contact with the surface of the oil-and-water mixture. The paper towel absorbed as much as it could, however, it didn’t recover sufficient amount of oil. It also absorbed a lot of water as it sank down to the bottom of the container.