in Your Water Filter? It's Called Reverse Osmosis!
Osmosis Water Filtration and You
by Josh Day
osmosis, now that's a mouth full.
you've heard of it before. But do you really understand what it is
and how it works?
go to Wikipedia:
osmosis (RO) is a separation process that uses pressure to force
a solution through a membrane that retains the solute on one side
and allows the pure solvent to pass to the other side. More formally,
it is the process of forcing a solvent from a region of high solute
concentration through a membrane to a region of low solute concentration
by applying a pressure in excess of the osmotic pressure. This is
the reverse of the normal osmosis process, which is the natural
movement of solvent from an area of low solute concentration, through
a membrane, to an area of high solute concentration when no external
pressure is applied. The membrane here is semipermeable, meaning
it allows the passage of solvent but not of solute.
membranes used for reverse osmosis have a dense barrier layer in
the polymer matrix where most separation occurs. In most cases the
membrane is designed to allow only water to pass through this dense
layer while preventing the passage of solutes (such as salt ions).
This process requires that a high pressure be exerted on the high
concentration side of the membrane, usually 217 bar (30250
psi) for fresh and brackish water, and 4070 bar (6001000
psi) for seawater, which has around 24 bar (350 psi) natural osmotic
pressure which must be overcome.
process is best known for its use in desalination (removing the
salt from sea water to get fresh water), but it has also been used
to purify fresh water for medical, industrial and domestic applications
since the early 1970s. (Wikipedia)
want it in more layman terms, I defined it myself in another article:
creme de la creme of filtration is water purified by reverse osmosis.
This process is so powerful that it's been called hyperfiltration.
Water is passed through a membrane so fine that it can remove pretty
much anything. There are also several stages of pre-filtration,
as well as a storage tank for purified water. Obviously, this system
[...] would take up some amount of space... imagine having a miniature
treatment plant under your sink!
read my other articles on water, you'll know I keep a number of fish
tanks of varying size and salinity (at one point I kept fresh, brackish,
and saltwater systems). Reverse osmosis is the ideal form of water
in marine aquariums as its pure and comes out at 6.0 pH, which is
great for mixing synthetic salt. Nitrates, phosphates, copper, chlorine,
and everything else that hitch along to your faucet tap are things
you don't want anywhere near sensitive marine life. Reverse osmosis
removes these impurities.
osmosis is the Superman of carbon. It can even pull out fluoride,
which is a reduced form of the element fluorine. Unfortunately, you
may not want to drink reverse osmosis on a regular basis as the water
is actually too pure -- minerals are lost along with toxins
in the process (2010 update: Click
here for information contrary to that statement, which may very
well be wrong). Even the most natural, pure water on the
planet, glacial water, appears microscopically "dirty" next
to reverse osmosis water.
drawback of reverse osmosis water filters are their output. For every
gallon of purified water, you can lose up to several gallons in the
process, depending on the quality of your filtration system. The reverse
osmosis system is quite bulky and consists of several cylinders and
a network of tubing.
more con for reverse osmosis is the cost. With systems starting at
about $260, the price only goes up.
want pure, clean water, consider a non-reverse osmosis water filter
like the one described below. The fluoride stays in, but a lot of
other things -- including pesticides and herbicides -- are removed.
Note: Click here
to visit the site where we purchased our water purifying unit that
produces crystal clear healthy water for less than 10 cents a gallon.
We like our Multi-Pure filter that we bought from this company so
much we became a distributor.
Throughout this entire website, statements are made pertaining to
the properties and/or functions of food and/or nutritional products.
These statements have not been evaluated by the Food and Drug Administration
and these materials and products are not intended to diagnose, treat,
cure or prevent any disease.