You can create a water purification model using cotton, gravel, sand, and coal to represent different stages.
This is a simplified version, but it will effectively demonstrate the basic principles of water purification. Here’s how you can set it up:
- Two plastic bottles (cut in half to create funnels)
- Cotton balls or cotton pads
- Activated charcoal or powdered coal
- Small container for filtered water
- Dirty water (to simulate impure water)
Stage 1: Cotton Filtration
Explanation: Cotton acts as the first stage of filtration, removing larger particles and debris from the water.
- Take the top half of a plastic bottle and create a funnel by placing a layer of cotton balls or pads at the neck. This represents the cotton filtration stage.
- Pour the dirty water through the cotton. Observe how the cotton traps larger particles.
Stage 2: Gravel Filtration
Explanation: Gravel helps to filter out smaller impurities and particles from the water.
- Take another plastic bottle top (cut in half) and place a layer of gravel at the neck. This represents the gravel filtration stage.
- Pour the water that passed through the cotton filter through the gravel. Notice how the gravel further refines the water.
Stage 3: Sand Filtration
Explanation: Sand acts as a fine filter, removing even smaller particles and impurities.
- In another plastic bottle top, add a layer of sand. This represents the sand filtration stage.
- Pour the water that passed through the gravel filter through the sand. Observe how the water becomes clearer.
Stage 4: Coal Filtration
Explanation: Activated charcoal or powdered coal can adsorb impurities like organic compounds, chlorine, and some heavy metals, improving taste and odor.
- Add a layer of activated charcoal or powdered coal to the last plastic bottle top. This represents the coal filtration stage.
- Pour the water that passed through the sand filter through the coal. Notice how the water becomes even clearer and cleaner.
Collecting the Filtered Water: Place a small container below the final stage to collect the purified water.
Observations: Observe how the water changes in clarity and cleanliness after passing through each stage. The final water collected in the container should be significantly clearer and free from larger impurities.
Remember, this is a basic demonstration. In actual water treatment plants, additional processes and chemicals are used to ensure the water meets specific quality standards. This model serves as an educational tool to understand the fundamental principles of water purification.