It is one thing to get water as a bi-product and to start an electric machine to produce water. It is not economical and you will be wasting lots of power for little water. That is beside the other concern of midlew.

You can use it as a backup source of "clean" water that needs boiling. But that is if there is not corrosin in your dehiumidifer. Corrosion will add iron, copper, and whatever metals to the water.