There are two ways to get water to drink from a muddy mess, evaporation and filtration.
Filtration is a process where the water is pumped through a porous
material. A porous material has very small holes that water can pass
through, but dirt and other pollutants cannot. This works well because
water molecules are much smaller than the organic materials that are
making the water muddy. Porous materials are made from woven natural
fibers such as cotton, woven or stretched materials such as nylon and
even certain special solid ceramic disks.
Evaporation uses relatively low boiling point of water to separate
it from the other compounds. To get the water you would need to place
the muddy water in a sealed container with a spout at the top. Attach
one end of a hose to the spout and put the other end in a glass. When
you put a heat source below the container with the mud, the water will
begin to boil and evaporate. As it evaporates it will rise and the
steam will get pushed into the hose.
The steam will cool in the hose if heat is allowed to flow by
conduction, convection, or radiation away from the hose. A rubber
garden hose may not be the best for this purpose as rubber makes a
not-so-bad thermal insulator. A long metal pipe may be the best bet
here. As the steam cools it will condense back into water and will drip
out the other end of the pipe (make sure it is tilted downwards in the
direction of a collection cup and not back into the container with the
muddy water). In the end your will have all the water in the glass and
all the dirt left in the sealed container.
(republished on 07/31/06)