Original text - Engels - Water that has been polluted can be returned...

Water that has been polluted can be returned to its original condition. When humans purify water they use the same process that nature uses, except that they speed up the process.

There are several ways to remove salt from water.One of the most common methods is distillation. In this process, salt water is boiled so that the water separates from the salt end becomes steam. When the steam cools, it returns to its water form minus the salt.
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