Reverse Osmosis type of filtering is by far the best and does a superior job
compaired to any other types of filtration systems available today.
From Wikipedia, the free encyclopedia
Reverse osmosis is a separation process that uses pressure to force a solvent 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.
The 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 2–17 bar (30–250 psi) for fresh and brackish water, and 40–70 bar (600–1000
psi) for seawater, which has around 24 bar (350 psi) natural osmotic pressure which must be overcome.
This process is best known for its use in desalination (removing the salt from sea water to get fresh water), but has also purified naturally occurring
freshwater for medical, industrial process and rinsing applications since the early 1970s.