Oil isn’t just for fueling cars. Are you wearing shoes right now? Chances are good that some parts of those shoes are made from petroleum oil. Now look at the fabric of your clothes, chair cushion, bedspread, carpet and drapes. If they aren’t entirely cotton or another natural fiber, many of these fabrics were made at least in part from oil. In the kitchen you may find fruits and vegetables grown with the help of fertilizers and pesticides, which are also oil-containing products. If you head to the bathroom, you might find medicines, lotions, toothpaste, shampoos and bandages made in part from oil. Oil products are everywhere, including outdoors: car tires, roads and, yes, the fuel that powers most motor vehicles.
Because oil is used in so many ways, great amounts of it are carried long distances to factories that turn it into the products that we have become accustomed to having. Every day, millions of barrels of oil are moved around, mostly on tankers—which can carry more than 200,000 tons each. Occasionally these tankers have accidents, or offshore drilling rigs are damaged, and oil spills into the ocean. One way environmental engineers try to clean spills is with sorbents—materials good at absorbing liquids. If you’ve used a sponge, paper towel or kitty litter, you’ve already used a sorbent. Now we will explore specifically which sorbents are good for removing oil from water.
If you tested them, did cotton balls and fur absorb oil better than coconut husks and feathers?
In this activity you tested some common household materials for their ability to act as good sorbents for vegetable oil. The original ratio of water to vegetable oil in the measuring cup was 3 to 1, as three cups of water and one cup of vegetable oil were used (and three divided by one equals three). Consequently, sorbents that absorbed more oil than water (“good” sorbents) would have a ratio greater than 3 to 1, whereas sorbents that absorbed more water than oil (poorer oil sorbents) would have a ratio smaller than 3 to 1. If you tested cotton balls and dog fur, you may have found they were relatively good sorbents, with a ratio of remaining water to remaining oil being approximately 5 to 1 or above.
If you made any oily messes, try cleaning them with warm water and soap. Much of the “waste” from this activity can be composted (such as vegetable oil, most newspaper, coconut husks, fur, feathers, etcetera); if you compost, look into whether you can compost the waste you have left over from doing the activity and then dispose of it properly.