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Arkansas Waterways

Water, Water Everywhere and Not A Drop to Drink

About 97% of the Earth's water is salty. Why not convert the ocean's salty water to pure salt-free water?

Ocean water can and is being desalted. There are many ways to desalt water. However, turning ocean water into fresh water can be expensive. The cost can be up to ten times more than the cost of normally obtained water.

Purifying Salt Water: Here are some methods used to convert salt water to fresh water!

DISTILLATION

When you boil salt water, the water turns into steam. The salt is left behind. The steam is cooled back into relatively pure water. This system works well but it is very expensive.

FREEZING

Salt water is frozen and then melted. During the process, the salt can be separated from the water.

ELECTRONIC

Salt dissolved in water normally breaks into two electronic parts called IONS. The salt ions are attracted electrically to special plastic sheets. The salt particles (ions) pass through microscopic holes in the plastic sheets. Water molecules are too big to pass through and stay behind.

BIOLOGICAL

Some algae (a water plant) and some bacteria have the ability to absorb salt. Algae and bacteria can dramatically reduce the amount of salt in sea water.

Build Your Own Salt Water Solar Still

  • Obtain a CLEAN wide mouth gallon jar with a lid.
  • Fill a small glass or paper cup with a mixture of salt and water.
  • Place the lid upside down in full sunlight.
  • Place the small glass with salt water in the center of the large lid.
  • Place the jar carefully on the lid as shown. It does not need to be screwed on.
  • Wait at least a half hour.

Describe what you see forming on the inside surface of the jar.

The sun's heat causes the water, but not the salt, to evaporate. Is the water on the inside surface of the jar fresh or salty?

Leave your solar still out a few hours. With a little luck you might end up with a little fresh water in the jar lid. Taste a tiny bit of the lid water. Is it salty?