Grade Level: K-12
Source: Nebraska Earth Systems Education Network, School of Natural Resources
By Kimberly Flessner
Each group will design a water filtration system and present to the class, why
they picked their design.
- 1 or 2 2-liter bottles
- 1 250ml beaker
- filtration materials (examples: soil, gravel, potting soil, cotton balls,
scrap material, charcoal, sand, woodchips, Styrofoam packing, charcoal briquettes)
- rubber bands
- Bunsen burner or heat source for evaporation
- "polluted water" (tap water with salt, food coloring, sand, and dish soap added to it)
- Each group of 2 or 3 need to design an idea for a filtration system.
Each design can use any three(3) of the filtration materials, in any order.
The groups will write a short paragraph describing why they used the materials
they did, and how they chose their order.
- Turn the top of the bottle over (neck down) to use for the filtration
chamber. Remove the cap and cover the opening with the screening, attaching
it tightly with a rubber band. This is to hold the filtration materials in the
- The group then assembles their designed filtration system and presents
their design to the class. They will explain why they chose the materials they
did, and also why they arranged them in the order they did.
- After the presentations, or during the next class period, each group
will be given a 250ml beaker full of "polluted" water.
- Their filtration system will be placed into the bottom to act as their
collection container. Then the "polluted" water will be poured into
the system and allowed to filter for 10 minutes. The collected liquid can be
tested for soap right away by taking a small amount in a test tube and shaking
it up. The other "pollutants" can be tested for by evaporating the
water away using the heat source.
- The groups' results will be compared to see which filtration system seemed
to be the most successful. A conclusion statement should be written as to why
they think it was the best.