How to Get Pure Water From Salt Water
A desalinator is a device that extracts pure water from salt water. Commercial desalinators are common in the Middle East, which has abundant oil but scarce drinking water. Desalinators usually function by converting water into steam with a combination of heat and low pressure. The steam is then condensed back into water without the salt. You can demonstrate this process at home with common materials.
Things You'll Need
- 1 qt. water
- 3 tbsp. salt
- Large bowl
- Small cup
- Plastic wrap
- Rubber band
- Ball bearing
Instructions
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1
Thoroughly mix the salt in the water untilcompletely dissolved. Fill the bowl with salt water but make sure the depth of the water in the middle of the bowl is less than the height of the cup. Put the cup in the bowl without allowing the water to overflow into the cup.
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2
Cut a section of plastic wrap large enough to cover the bowl's top. Place the plastic wrap over the bowl and push down slightly in the middle of the wrap to create a slight amount of slack. Stretch an appropriately sized rubber band over the bowl's circumference so that the plastic wrap forms a tight seal.
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3
Place a small round weight, such as a ball bearing, in the middle of the plastic wrap. The plastic wrap should sag as much as possible without dropping below the top of the cup in the bowl. Make sure that the sag is directly over the middle of the cup.
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4
Find a warm location for the bowl that's exposed to direct sunlight, such as a window sill. The heat causes the water to evaporate and accumulate on the plastic wrap, since the water can't escape from the bowl.
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5
Wait for the droplets to slide down the slope of the plastic wrap and drip into the cup. The salt remains in the bowl since it doesn't evaporate, so the water in the cup will be fresh.
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