Science Project on “Water Purification”, Project Experiment Topics on Environmental Science for Class 8, 9, 10 and 12 Students.

Water Purification

Materials Required:

1. An adult
2. Smallest-size flat tuna can
3. Salt
4. Water
5. Spoon
6. Large, wide-mouth jar with lid
7. A sunny window
8. Use of refrigerator

Most of the oceans and seas in the world are made up of salt water. When the water evaporates, what is left behind is salt. But is evaporated water still salty? Let us evaporate some salt water and check if it is still salty, or whether the salt is gone.

Ask an adult for a small clean can (the inside edge can be sharp where the lid was cut away, so you need to be careful). Fill the can with one-quarter salt. Add the water until the can is three-quarters full. Stir it slowly, until the salt is completely dissolved.

Take a large, wide-mouth jar. A mayonnaise or peanut butter jar will be better. Clean the jar thoroughly, then without spilling any of the salt water, lower the can to the bottom of the jar. Screw the lid onto the jar tightly. This gives it a “closed environment”.

Place the jar near a warm, sunny window for several hours. The sun’s heat will cause water to evaporate. When the sun starts to set, carefully place the still-closed jar in the refrigerator. The change in the temperature, from hot to cold, will now make the evaporated moisture in the glass jar condense and water droplets will collect inside of the jar. Open the jar and taste the condensed droplets of water that have formed inside of it. Does the water taste salty or is it clean and pure?

You can also find out if evaporation can purify dirty water. Try this by repeating the above experiment, but instead of mixing salt and water, by mixing a little soil into the water.