Solar Stills
Solar stills have been
used to desalinate
water in survival
situations on boats
and islands for
generations. Most
marine-based first aid/
survival kits include compact solar still
kits to be used in emergency situations.
Solar stills function in a similar way to
a salt pond, except it traps evaporating
fresh water molecules. Essentially, a
clear plastic or glass cover is sealed
air-tight over a salt water reservoir
then set under the hot sun. As fresh
water evaporates from the salt pond, it
condenses again into liquid form on the
clear covering. To aid in the process,
the clear cover should be situated in
an angular fashion. This positioning
ensures that the condensed water
molecules eventually drain down the
interior surface of the clear covering and
into an awaiting tube or container.
It should be noted that solar stills work
quite slowly and they are rendered
obsolete on cloudy days. Therefore,
if individuals are serious about
desalinating large amounts of water
with solar stills, they should construct
a large number of
these rigs and take
advantage of sunny
days.
Thermal Stills
Thermal distillation is relatively
easy to accomplish at home and
is a popular method for creating
drinking water in survival situations.
It utilizes heat to boil salt water, a
process that separates the water and
salt molecules. Simply fill a metal
container partially full of seawater and
boil it over a heat source. Next, place a
tall dish in the middle of the container
with the boiling salt water. The top of
the small dish must be well above the
salt water line. After that, a convex lid
(the curve faces downward) must be
placed atop the larger metal container,
forming a relatively tight seal. The
center of the lid must be directly
over the midpoint of the tall dish. If the
system is set up correctly, the steam from
the boiling salt water will condense on
the convex lid and drip distilled water
into the interior tall container.
It’s apparent that as humanity’s need
for water rises, technology will have
to keep up with the demand. On a
large scale, oil-rich desert countries
such as United Arab Emirates and
Saudi Arabia have initiated massive
desalinization programs to supply
their people with potable water. Large-
scale desalinization efforts will also
likely spread west, as the average
American citizen uses approximately
130 gallons of fresh water on a daily
basis. This staggering statistic
represents a misguided sense of fresh
water abundance; this ideal becomes
blatantly evident in times of water crisis
such as the California drought of 2012-
2016. Until those large-scale projects
become the norm, however, at-home
desalination is an option that can be
used to alongside reduced water usage,
such as watering gardens with extra
grey water from showers and dishes.
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