cleaning up an Oil Spill
This experiment shows that cleaning up after an oil spill is nearly impossible. Students can use various sorbents to attempt to clean up a small oil spill in a dish and they will be able to see the complications that occur and can then compare this to a real world situation such as the effects of the BP oil spill disaster.
• one 28 cm x 19 cm x 4 cm clear glass baking dish (or equivalent)
• blue food coloring
• 12 tbsp. vegetable oil
• 8 tbsp. pure cocoa powder
• 1 tsp. table salt
• a tablespoon
• a teaspoon
• 5 paddle-pop sticks
• a coffee mug
• sorbents (paper towel, cotton balls, rag, string, nylon pot scrubber, sponge, Styrofoam cup, garden peat moss)
• 1 squirt of liquid dishwashing detergent
• tweezers or tongs
• bird feathers
To prepare the fresh water:
• Fill baking dish with cold tap water within 1 cm of rim.
• Add 5-6 drops of food dye.
• Mix dye and water with a stirring stick. Let solution settle.
To simulate crude oil:
• Place 3 tbsp. of vegetable oil in mug.
• Add 2 tbsp. of cocoa powder.
• Mix cocoa powder and oil thoroughly with a paddle pop stick.
To contaminate fresh water:
Very slowly pour simulated crude oil from a height of 1 cm onto the top of the fresh water dish. If you pour the oil too quickly, the experiment won't work.
Wait 3 minutes.
To test the sorbents:
Place a small sorbent sample into the centre top of the contaminated fresh water.
Remove sorbent with tweezers or tongs.
Repeat step 1 with other sorbent samples.
Clean out contaminated fresh water.
Prepare new simulated fresh water following instructions above.
Add detergent to the oil-contaminated fresh water.
To determine how oil affects feathers:
Dip feather into oil-contaminated fresh water.
Repeat all of the above procedures substituting an ocean for the fresh water. To prepare the ocean, follow the fresh water procedures except add 1 tsp. of salt and mix it with the water before step 2.
Though the sorbents seem to absorb SOME of the oil, they don't seem to clear enough to make an obvious dent in the issue. Some of the pollution also sinks to the bottom of the water making it impossible to absorb from the surface.
Students can observe this problem and then be able to think about the difficulty of cleaning this kind of mess on a larger scale, in the middle of the ocean, especially when the problem also incorporates living creatures and various plant organisms.