Oil Spill Cleanup Lab Summary: Students make a motor oil emulsion, compare different factions of spilled oil and their effects on natural materials, and experiment with different oil cleanup methods. Grade Level: 6-12 Duration: 60-90 minutes Objectives: - Students will evaluate various clean-up techniques and their efficiencies. - Students will demonstrate use of various clean-up techniques for an experimental oil spill. - Students will learn about different types and fractions of spilled oil and their effect on the living and non-living environment. Materials: - Blender or egg beater that will not be used for food again - Large mixing bowl - Extension cord - Motor oil (used motor oil from automotive shops works well) or vegetable oil (easier to clean and dispose of) - Water - Salt - Detergent / soap - Rubber gloves for each student - Disposable plastic/tin dishes, one for each group (baking pans work well) - String - Plastic straws - Scissors - Popsicle sticks - Plastic spoons - Eyedropper - Oil absorbent pads, cut into small pieces - 2 glass jars with lids - Natural materials: wood, feathers, fur, rocks - Plastic or glass jar - Squeegee Background: Before beginning the lab, students should have knowledge of oil spill cleanup methods described in the preceding lesson ( Oil Spill Response Methods ). Procedure: 1) Fill two jars with equal amounts of salt and freshwater. Measure an equal amount of vegetable oil (or motor oil) into both. Have students shake each jar an equal number of times. After shaking, start a stopwatch and watch the oil in the jars settle. Make observations about how the oil behaves in each type of water, and what that means for oil pollution. Prince William Sound Science Center_A.Dou-Wang_Version 4.2011 1
2) Pour some water and motor oil into a large mixing bowl (about one part motor oil to 2 parts water). Mix with egg beater for at least 20 minutes. The froth which forms on top is mousse. Have the students skim the mousse off and measure it. Is it more or less than the amount of oil that was poured into the bowl? Ask them what happens to an oil slick at sea that is agitated by high winds and strong seas for 2 weeks or more, as was actually the case with the Exxon oil in the Gulf of Alaska. Thick, foamy mousse blew ashore and remained in the intertidal areas. Pour some of your mousse onto a few dry rocks to illustrate its tendency to cling to the shore rather than wash back out to sea. (Save your oiled water and rocks for the next two activities). This experiment can be done in a blender, but the oil will be impossible to clean out completely. Any oiled items bowl, beater, tray should not be used for food ever again. Remind students that motor oil is toxic - a hazardous substance they should breathe as little as possible and not touch without gloves. The mousse will be stuck to the bottom and sides of the blender, with the water sitting on top. (This happens because the plastic that composes the blender is made from petroleum and is oleophilic.) To remove the mousse, first pour out the remaining water, which will have a sheen. Scoop out the mousse with a spoon. Drop a blob of mousse on a dish of clean water; as it spreads out you will be able to see the bubbles of air and water imbedded in the mousse. (The air and water will fizz out of the oil rather quickly this is because it s not a stable emulsion, because the mixing energy wasn t of very long duration.) [Since mixing the mousse takes a long time, you will probably want to complete the next activity while an assistant finishes making the mousse.] 3) Dip some feathers in water to see how the drops roll off. Healthy feathers protect birds by blocking out wind and rain and trapping warm air underneath. Now dip the feathers in the oil and mousse. (If the oil clumps on too thickly, wipe some oil off with an absorbent pad.) See how the feathers are now matted together. Once oiled, they lose their waterproofing. Birds that are oiled often die of hypothermia because they can no longer trap air under their feathers to keep warm. Try to clean off the feather by dipping it in plain water and soapy water. Observe the effect of soap on the oil and the feather. (If you let the feather soak in soapy water and look closely, you can see the oil breaking into small pieces.) After the soap has washed most of the oil off of the feather, take it out of the soapy water and examine it. Is it still able to keep its shape and protect from water and wind? The soap, while it washed off the spilled oil, also removed the natural oils that make the feather smooth and waterproof. 4) Have students work in pairs to clean up a small oil spill using the various materials. Give each group a pan, filled halfway with water, and drop a few teaspoons of oil on top. Prince William Sound Science Center_A.Dou-Wang_Version 4.2011 2
(Give some groups regular motor oil, others the mousse.) Their goal is to contain the oil and remove it from the water. Also give students a variety of natural materials (rocks, feathers, leather, etc.) to oil and clean. Explain to students that they will investigate various clean-up products and methods, such as: skimmers and booms, dispersants (detergents), oiled seaweed or pom-poms, absorbent pads, suctioning (eyedropper), and collecting with buckets. Discuss with them creative solutions to cleaning up oil spills. Allow them to list alternative methods and experiment with them. First try containing the oil spill with booms. Decide on one material to use as a boom, and use it to contain the oil spill. How well does it work? What if there was rough weather? Simulate rough weather by blowing over the surface, or fanning the surface with a card. Have students describe their results in their journals. 5) You can demonstrate an oleophilic skimmer by placing a glass or plastic jar in a pan of oil and rotating it so oil adheres to the surface. Then use a squeegee to remove the oil from the jar. 6) Now use at least two other techniques for cleaning up the oil spill such as dispersing the oil and absorbing the oil with various materials. Try to clean the natural materials. You can have the groups compete against each other to see who can clean up their oil and oiled materials the fastest or most thoroughly. Which methods worked best? Which was more difficult to clean, the regular motor oil or the emulsion? 7) One of the conditions that hampered the Prince William Sound oil spill clean-up was stormy weather. Set up the experiment again, and simulate stormy weather by blowing over the surface or by moving a card through the water. Repeat two of the techniques with heavy oil and rough water. Record the data. Encourage students to experiment with various materials or to design their own clean-up device or technique. 8) Clean up the lab stations and dispose of the oil and oily wastes properly. Discuss the following questions, or have students use them as a prompt for a journal entry: - With which method were you able to most rapidly clean up the oil spill? - Ocean spills are often contained by placing booms, or barriers around the oil. What types of booms did you use to contain your oil spill? How well did they work in rough weather? - Which of the techniques removed oil by absorption? - Some people say that absorption techniques simply move the oil spill from the water to the land. What do you suppose they mean? - What effect did detergent have on your oil spill? - Did the detergent make your clean-up technique more effective or less effective? Please explain. Prince William Sound Science Center_A.Dou-Wang_Version 4.2011 3
- How would you determine if the area affected by the spill was clean enough, and when to stop cleaning? How clean is clean enough? This is an area of debate among scientists, agency representatives, responsible party, and local stakeholders who disagree about what "clean" really means. Have students use their journals to summarize, in one or two paragraphs, what they have learned about oil spill clean-up. Homework: Give each student a copy of each of the NOAA fact sheets (links in Resources below) on oil types and tarballs. Each student should pick one oil type (crude, bunker C, or diesel) and explain, in their journal, which cleanup methods they would and wouldn t use for this type of spilled oil and why. Resources: Alaska Oil Spill Curriculum, grades 7-12 (3 rd edition). Prince William Sound Science Center and Prince William Sound Regional Citizens Advisory Council. 2007. Available online at www.pwsrcac.org/outreach/education.html NOAA Oil Characteristics fact sheets: - Alaska North Slope Crude: http://response.restoration.noaa.gov/book_shelf/970_crudes.pdf - No. 6 Fuel Oil (Bunker C): http://response.restoration.noaa.gov/book_shelf/971_no_6.pdf - Diesel: http://response.restoration.noaa.gov/book_shelf/974_diesel.pdf - Tarballs: http://response.restoration.noaa.gov/book_shelf/488_tarballs.pdf Prince William Sound Science Center_A.Dou-Wang_Version 4.2011 4
gravel beaches (on the map above, purple line segments denote locations of eroding bluffs). Shades of green denote shorelines of moderate sensitivity (on the map above, green line segments denote areas of riprap). Large habitat areas, such as tidal flats used by shellfish and wetlands used by shorebirds or waterfowl, are shown as colored polygons (above, orange hatched polygons denote shellfish habitat, used by horseshoe crabs). 2. Sensitive biological resources, such as seabird colonies and marine mammal hauling grounds, are depicted by special symbols on the maps. On the map above, a seal symbol marks habitat used by gray and harbor seals. 3. Important human-use resources, such as water intakes, marinas, and swimming beaches, are also depicted with symbols. (In the map section above, four symbols denote historic sites, one denotes a boat ramp, and one denotes a public park.) The Back of an ESI Map Much of the information on an ESI map is shown in a table on the back of the printed copy of the map (some older maps do not include this table of information). The "backof-the-map" table lists sensitive plant and animal species that live in the area shown on the map. It shows when each species is present in the area, and what that species is doing during different seasons (for example, a bird species may be nesting, laying eggs, hatching, or fledging young birds). The back of the map is also where you'll find contact information for important human-use locations shown on the map. Although ESI maps are important tools for spill responders, they may not reflect the current shoreline situation, because biological resources and human uses of shorelines can and do change, sometimes quickly. For up-to-date information, contact your local natural resource management agencies. Source: NOAA National Ocean Service Office of Response and Restoration Prince William Sound Science Center_A.Dou-Wang_Version 4.2011