Try This: Clean an Oil Spill

Using household objects, Design and construct floating boom that will prevent an oil spill from reaching the beach and absorb as much oil as possible from a spill.

Oil and Water

Oil and water don't mix. A chemical engineer would say oil is hydrophobic, or not attracted to water. Oil is also usually less dense than water, so it floats.

If you put a few drops of oil into a pan of water, the oil will stick together in small pools on the surface of the water. Even if you stir the water, the oil will return to the surface or cling to the sides of the tray rather than mix into the water.

Oil in water behaves differently if you add a surfactant. This is a compound that lowers the surface tension between the 2 liquids, allowing the oil to break down in very small droplets than can then be dispersed through the water. A dishwashing liquid can act as a surfactant.

If you add a drop or two or dishwashing liquid to your tray of water with the floating pools of oil, you'll notice that first, the oil spreads out - away from the detergent. But if you stir the water again the oil no longer pools - it becomes small droplets that stay suspended in the water.

These properties of oil create some unique challenges and opportunities when oil and water meet in the environment.

Oil Spill: Environmental Hazard!

Oil spills in the ocean damage and sometimes destroy wildlife and fragile ecosystems. Engineers work to design drilling and transport technology to prevent spills, but accidents happen. When they do, engineering is critical to stopping, containing, and cleaning up the mess.

The Challenge

The first step is to prepare your “beach.” You can use any large tray, pan, or plastic container. Large food storage containers, plastic under-bed or closet storage containers, or even an aluminum roaster pan would work. Pour sand or other "beach" material into your tray so that it fills about 1/3 of the tray. Pour water into the other 2/3 of the tray. Pour only enough water to touch the sand, but not cover the sand completely.
Setting up the beach first gives you the chance to measure the maximum size of your oil boom. Think about a design for your oil boom that will optimize oil containment and absorption. Sketch out your ideas.
Collect your boom-building materials and construct your oil boom based on your design.
Measure out 3 tablespoons of oil and pour into a graduated cylinder or measuring cup. Make note of the level of oil in your graduated cylinder either by marking it or writing down the level on a piece of paper. When it comes time to test out your boom and scoop oil out of the water and back into the graduated cylinder, this marking will allow you to easily compare how much oil you started with versus how much oil you remove from the spill.
Place your oil boom on top of the water. Now pour the oil into the water behind the boom (away from the sand).
Does your oil boom contain the oil? Does it absorb any of the oil?
Try gently lifting one end of the tray slightly to create waves – does any of the oil reach the beach?
Use a spoon to scoop out as much of the oil from behind your boom as you can and pour it back into your graduated cylinder or glass measuring cup (Note: it will be hard to scoop out the oil without also scooping out some water, but try to get as little of the water as possible for accuracy of measurement). How much oil can you remove this way? Are you able to get about 75% of the oil out?
Try adding a squirt of dish soap to the water to disperse the remaining oil. Does your boom still contain the oil? How about when waves are created? Can you skim out the smaller droplets with your spoon?
If the oil manages to escape your boom, clean out your pan to remove the oil, add fresh water, modify your oil boom design, and try again.

Boom-building materials

What materials could you use to create an oil boom? How might you decide the best material for containing the spill? What materials would work best for absorbing the oil? Try to use a mix of materials so that your oil boom can do both.

Sponges
Straws
Cotton balls
Gauze pads
Pieces of rags
Popsicle sticks
Corks

Craft foam
Q-tips
Napkins or paper towels
Small plastic bottles, caps, or containers
Aluminum foil
Fishing bobbers
Paper boats

When using materials around the house, you may want to test your materials. Do they float? Do they absorb water and/or oil? How can individual pieces be connected?

Try this next!

If you enjoyed this activity – take it further with more design challenges!

Try creating a larger “oil spill” (1/4 cup of oil). Can your boom contain and absorb the larger spill? What modifications to your boom design would make it more effective at containing or absorbing a larger spill
Add a fan, or just blow on the oil behind your boom. Does wind blowing on the surface cause it to escape the boom? How might you deal with the effects of wind?
Once the oil is contained, it may be helpful to tighten the containment area so that all of the oil can be removed. Can you design a boom that would allow you push all of the oil into a smaller space? Can you think of other ways besides a spoon for removing the oil behind the boom?

TRY THIS!

Design and construct floating boom that will:

Prevent an oil spill from reaching the beach
Absorb as much oil as possible from a spill

Test your design's performance with wind and waves.

What You'll Need

Large tray, pan, or plastic container*
Water
Sand or small pebbles
Cooking oil
Dish soap
Measuring cup or graduated cylinder
Materials to build your boom. Check the Boom Materials section for suggestions.

*We recommend using one that’s at least 3" deep, 8" in width, and 8" in length.

Be Safe!

Always check with a parent or guardian before you start a project and make sure it is okay to use materials you find around the house.

Introducing EngineerTeen!