Margaret D. Andrews
Objective
The student will demonstrate an understanding of the many steps it takes to deliver drinking water to the consumer and the importance of filtering and disinfecting drinking water.
Materials
2 liter plastic soda bottles with bottoms cut off
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sand
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old panty hose or knee highs
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water
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elastics
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pebbles
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plastic containers for drainage
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charcoal
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Thoughts and Ideas to Consider Before You Begin
How do you think the time of year affects how much water is processed at the treatment plant?
Suppose you went to a foreign country where you were told not to drink the water because it wasn’t disinfected. What other things would you have to avoid in order not to get sick from the water?
Procedure
1.
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Remove the cap and put the nylon screen over the opening. Secure it with elastic.
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2.
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Pour in a layer of gravel. Pour a layer of sand over that to create a sand layer. Use charcoal to create another layer.
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3.
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Turn the bottle upside down into a container to drain.
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4.
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Scoop some dirt containing twigs, grass, etc. Mix with 2-3 cups of water. Pour into the wide end of the bottle. Let it filter through. DO NOT DRINK THIS WATER, IT HAS NOT BEEN DISINFECTED.
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5.
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Observe the water as it passes through the filtering process. Is the water coming through the filtering process cleaner than when it entered? Why?
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Additional Questions and Activities
1.
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What would happen if you rearranged the order of the filtering system? Try it.
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2.
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What other kinds of things can be used for filtration?
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3.
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Have a contest to see who can create the filtration system that is most effective.
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