In some communities, people must separate their recyclable materials into different categories, such as glass (clear or colored), paper, cardboard, aluminum, plastic, etc. Other communities use single-stream recycling, in which everything is put into one large container; sorting occurs later.
If you watched the recycling center videos, you saw that they use some pretty cool methods for separating trash into different types. Sometimes, it's very simple, with a trained sorter picking items out by hand. Other separation methods use magnets or flotation. In this experiment, you will investigate different items that might be in the trash, and will try to figure out ways to separate them all.
What You'll Need:
Pieces of different plastics about 1 inch (2.5 cm) square (find plastics with different numbered recycling codes to ensure that they're different)
Aluminum foil (1 inch or 2.5 cm pieces)
Newspaper (1 inch or 2.5 cm pieces)
Copier paper (1 inch or 2.5 cm pieces)
Knitted wool or acrylic item (like a hat or mitten)
1. Place the magnet near all the different kinds of trash you've collected. Which kinds are attracted to the magnet? Could you use a magnet to remove these from the recycling stream?
2. Rub the knitted item on your hair to give it a static charge. Are any of the trash items attracted to the charged knitwear?
3. Place all of the pieces of trash on a table and aim the blow dryer at them. Turn the dryer on. Which types of trash get blown about, and which ones stay put.
3. Fill the bowl with water and place all of the pieces of trash in the water, one at a time. Which ones float, and which ones sink?
4. Using what you have found, can you figure out a series of sorting techniques that will let you separate all of your trash into different categories? You can use techniques more than once if that helps. If you can't, which things are hardest to separate?
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