Earth Day is a special celebration in April each year, in which people show support for environmental protection. Here’s an interesting experiment that explores filtration. Water is an important resource, and clean water is vital to life on the planet. Learn first hand about water pollution and how filtration works.
- 2 Glass Jars like Mason Jars
- Gravel or small pebbles
- Measuring Cup
- 3-4 Coffee Filters or Napkins
- Dirty Water – Can be collected by taking water with some dirt in it from a pond or puddle
- A Plastic Cup with a Hole Cut in the Bottom or half a water bottle/soda bottle without the lid
- Take the plastic cup with a hole cut in the bottom or the soda bottle and layer the napkins or the coffee filters inside.
- Next, add about a ½ cup of sand. Then, add a ½ cup of gravel.
- Put the cup into an empty jar.
- Take the dirty water and pour it through the plastic cup with the layers and watch the water filter through the cup into the jar. Leave some of the dirty water behind to compare.
- Compare the filtered water to the water that’s dirty. What do you notice?
- Want to see what was filtered? Dig through the sand, gravel and coffee filters/napkins to see what was removed by the water by each material. Don’t drink the filtered water in the filtered experiment – actual filtration takes much longer!
- Try filtering the same water again through clean sand, gravel and coffee filters. What do you notice now?
- Expand the experiment by making dirty water with different types of contaminants like oil, food coloring or spices. Which materials work the best to clean the water? Which contaminants are the hardest to remove?
What’s Filtration and Why Do We Need It?
In some places in the world, people don’t have access to clean water and people can get sick from drinking dirty water. Water filters remove particles and impurities from water. Filtration is any of various mechanical, physical or biological operations that separate solids from fluids by adding a medium through which only the fluid can pass. In nature, water is filtered through sand, soil, gravel, and even beneficial bacteria!
Try different types of material in this experiment and have fun learning about water filtration. This month, remember to give a big thank you to our special planet and learn how you can improve your environment!