(Earth science for ages 10+)
One of the primary sources of energy in the world is oil. It is used to power vehicles, to heat houses and other buildings, and to produce electricity. Oil comes from petroleum, which is a naturally-occurring liquid that formed millions of years ago beneath the Earth’s surface.
To get the oil, engineers, geologists, and oil drillers have to locate large pockets of petroleum (called wells) and drill deep into the Earth to pump it to the surface and transport it to refineries, where it can be made into the oil and other petroleum-based products used around the world.
These wells are found all over, including below large bodies of water like lakes and oceans.
Sometimes, the pipelines that transport petroleum or the rigs themselves can malfunction or break, leaking tons of oil into nature, including the ocean, rivers, lakes, and other sources of water.
When this happens, emergency environmental clean-up efforts are needed to keep our water clean and protect animals from the dangerous impacts of oil spills.
Luckily, oil and water do not mix together very well, but unluckily, it can still be very difficult to separate and remove the oil from the water.
Although oil spills are serious environmental disasters that have long-lasting impacts on wildlife and people, you can have some fun at home by experimenting with different approaches to cleaning up oil and learning a bit more about our environment.
The video above shows a couple of ways that could be used to clean-up an oil spill in a body of water.
There are plenty of other methods you can test at home, and some of those (not shown in the video) will also be included in the instructions below. Feel free to test other hypotheses and see what you can come up with! Here’s what you need to get started:
Blue or green food coloring
Oil (any cooking oil would work)
Bowls or cups (1 would work or multiple to test different methods)
Cotton balls or gauze
Liquid dish soap
Polyester fabric (small piece of towel, winter glove, old sock, etc.; light-colored will work best)
Sponge (white or light-colored would be best)
Any other materials you would like to test
Adult supervision (Adult supervision at all times please)
- First, add water to your cup or bowl. This will model a body of water like a lake or ocean. Add 3-4 drops of food coloring per 1 cup of water in your bowl.
- Measure out 6 tablespoons of oil into a separate small bowl or cup. You may need more or less depending on how many clean-up methods you would like to test, but this is a good starting point.
- Add to the oil 3 teaspoons of cocoa powder. Again, you may need more or less depending on the amount of oil used, but keep a ratio of ½ teaspoon of cocoa powder per 1 tablespoon of oil. Mix the oil and cocoa together to dye the oil brown (this will make it easier to see in the water).
- Using the eye dropper, add some of your brown oil to your nice, fresh blue water. What do you notice about the oil? Does it mix with the water? Does it float, sink or do both?
- You are ready to begin testing different methods of cleaning oil out of water. **Keep track of your observations as you test each clean-up method. Ask yourself questions like:
- Is this pretty easy or hard?
- What is happening to the oil?
- Are you mostly cleaning up the oil, or are you also getting a lot of water? (Remember, the oil is brown and the water is blue!)
- How long does it take to clean up the oil?
- Using a cotton ball or piece of gauze, try to soak up the oil and avoid the water. When finished, add more oil to test the next method.
- Using the plastic spoon, skim the surface of the liquid trying to only remove the oil. When you have gotten a spoonful, pour the captured oil into a clean bowl or cup and go back for more. Try to remove as much of the oil as possible. When finished, add more oil (and water if necessary) to try the next method.
- Using the polyester material (sock, towel, or whatever you have around the house), try to absorb the oil. Try to use a light-colored material so you can tell if the liquid you are absorbing is oil (brown) or water (blue). Again, add more oil when you are finished testing the polyester.
- Next, try using a sponge to absorb the oil. Remember, you want to get as much oil as possible and leave as much water as possible. Add more oil (and water if necessary) to test the next method.
- Add 1-2 drops of liquid dish soap. What happens to the oil? This method also requires the use of some material to absorb the oil. Try using another cotton ball, polyester fabric, or sponge. When you are finished with this method, you will need to create a fresh batch of water and oil (follow steps 1-3).
- Try removing the oil with corn meal by sprinkling it over the oil spots and using a spoon to remove it. Again, create a new batch of water and oil after testing this method.
- What other products might work to clean the oil out of the water? Get creative and try other things you have around the house. If you use a method that mixes in with the water and oil (like the corn meal and dish soap), remember to make a fresh batch before testing a new method.
Oil spills are tricky to clean up! Many of the methods you have tested can work really well when you are only cleaning a couple of tablespoons of oil from a cup of water, but imagine trying to separate millions of gallons of oil from a large lake or ocean!
How much more difficult would it be to clean oil from moving water like a river? Oil can be very useful for humans, but when it’s not handled well, it can be terrible for the environment.