How to Make an Easy Water Purifier

Water purification systems can be made in your own home.

With a growing world population and increasing water scarcity, water purification methods are becoming ever more popular. There are two types of contamination, biological and chemical, and they require different treatment methods. This article highlights a method of removing biological contamination.

Things You'll Need

• 2 plastic drinking water containers, 5-liter
• 2 cups of gravel
• 25 g of activated carbon
• 3 cups of fine sand
• 3 cups of coarse sand
• 1 sheet of filter paper
• 4 thick rubber bands
• 1 electric saw
• 1 ruler
• 3 liters of clean tap water
• 3 liters of dirty water

Instructions

Instructions

1. Using the saw cut 8 inches off the bottom of one water bottle (bottle A.)

2. Remove the bottle cap. Attach the filter paper to the outside of the bottle neck using the rubber bands to secure it in place. Make sure the paper is fixed tightly and securely with no gaps.

3. Cut 8 inches off the top of the second water bottle (bottle B).

4. Invert bottle A so the neck is pointing toward the floor. Insert it into bottle B. Ensure the bottles fit tightly into each other and that there are no gaps. Bottle A will become the filter and bottle B the collection point.

5. Pour the gravel into bottle A. The filter paper should prevent the gravel falling into bottle B. Add the coarse sand on top of the gravel and then pour the fine sand on top of the coarse sand. Spread the carbon on top of the fine sand. A layered effect should be created.

6. Pour three liters of clean tap water into bottle B. This is needed to clean the filter. The filter is complete.

7. To test the effectiveness of the filter, pour two liters of contaminated water into the filter. The water collected in bottle B should be clear.

Tips & Warnings

• For the rocks use washed aquarium rocks. The best fine sand is beach sand. Cotton wool can be added to the filter for greater effect.

• .

• Keep body parts well away from the saw when you are cutting. Keep children away from the machine.

• Keep the materials out of reach of small children.

• This filter removes biological contaminants only. Do not use it if you think your water has been contaminated with chemicals.

References

• The Water Page: Water for Basic Needs
• Red Flint: Sand and Gravel: Products
• Thinkquest: Water Filter Experiment

Resources

• Practical Action: Sand and Gravel Filters