The purified water is so pure that it
stored when added to a glass polluted. Reverse osmosis water is the most widely used
prevent corrosion and salt deposits in power plant turbines, boilers and pipes.
Also, this technology can be used for seawater desalination. Sometimes, reverse osmosis is
used to purify
liquids that contain water an undesirable substance such as for the purification of ethanol.
- Nanofiltration - is a relatively new filtration method used for sparingly dissolved
for the softening of water containing substances such as surface water; and
removal of disinfectants and other organic matter. Nanofiltration
membrane pore size of 1 to 10 nanometers, less than microfiltration and
ultrafiltration, but only higher than the pair of reverse osmosis membranes.
Historically, nanofiltration and other membrane technologies have only been used
separation of molecules in aqueous systems, usually water softening,
separating "solid" Ca2 + and Mg2 + ions. Recently, nanofiltration has been increasing
more commonly used in other industries such as dairy or juice
production. Compared to reverse osmosis, nanofiltration is found to be lower
energy consumption, but this method does not trap monovalent ions.
- Ultrafiltration is a membrane filtration method in which, under pressure,
the materials are separated through a semiconducting membrane. Particulate matter and large
molecular weight substances are retained in the so-called concentrate, and
water and low molecular weight substances penetrate through the membrane into
filtrate. In industry, this separation process is most commonly used for concentration
macromolecular (10 ^ 3 - 10 ^ 6 Da) solutions, especially protein solutions. This one
technology is used for blood dialysis. Ultrafiltration can be used for solids
particles and macromolecules from surface water, thus obtained
drinkable water. Pathogen removal efficiency is 90 - 100%. In many cases microfiltration is
for pre - treatment of water before supplying it to
reverse osmosis devices.