Reverse Osmosis, also known as
Ultra-Filtration by the industry,
represents state-of-the-art in water
treatment technology. Reverse Osmosis
(RO) was developed in the late 1950's
under U.S. Government funding, as a
method of desalinating sea water. Today,
reverse osmosis has earn its name as the
most convenient and thorough method to
filter water. It is used by most water
bottling plants, and by many industries
that require ultra-refined water in manufacturing. Now this advanced
technology is available to homes and
offices for drinking water filtration.
How It Works
In short, it is the process by which water molecules are forced through a 0.0001
micron semi-permeable membrane by water pressure. Long sheets of the membrane
are ingeniously sandwiched together and rolled up around a hollow central tube
in a spiral fashion. This rolled-up configuration is commonly referred to as a
spiral wound membrane or module. They are available in different sizes for
processing different quantities of water. Typically, a module for home water
treatment is as small as 2" diameter and 10" long, while one for industrial use
may be 4" diameter and 40" long.
For the
membrane to be usable it must be in some type of container (membrane
housing) so pressure can be maintained on its surface. It is this
pressure that supplies the energy to force the water through the
membrane, separating it from unwanted substances. The most amazing
aspect of RO is that the substances left behind are automatically
diverted to a waste drain so they don't build up in the system as with
conventional filtering devices. This is accomplished by using a part of
the unprocessed water (feed water) to carry away the rejected substances
to the drain, thus keeping the membrane clean. This is the reason to why
RO membranes can last so long and perform like new with minimum
maintenance even after years of operation.