S Reverse osmosis, also known as
hyperfiltration, is the finest filtration known. This process will allow
the removal of particles as small as ions from a solution. Reverse
osmosis is used to purify water and remove salts and other impurities in
order to improve the color, taste or properties of the fluid. It can be
used to purify fluids such as ethanol and glycol, which will pass
through the reverse osmosis membrane, while rejecting other ions and
contaminants from passing. The most common use for reverse osmosis is in
purifying water. It is used to produce water that meets the most
demanding specifications that are currently in place.
S Reverse osmosis uses a membrane
that is semi-permeable, allowing the fluid that is being purified to
pass through it, while rejecting the contaminants that remain. Most
reverse osmosis technology uses a process known as crossflow to allow
the membrane to continually clean itself. As some of the fluid passes
through the membrane the rest continues downstream, sweeping the
rejected species away from the membrane. The process of reverse osmosis
requires a driving force to push the fluid through the membrane, and the
most common force is pressure from a pump. The higher the pressure, the
larger the driving force. As the concentration of the fluid being
rejected increases, the driving force required to continue concentrating
the fluid increases.
S Reverse osmosis is capable of
rejecting bacteria, salts, sugars, proteins, particles, dyes, and other
constituents that have a molecular weight of greater than 150-250
daltons. The separation of ions with reverse osmosis is aided by charged
particles. This means that dissolved ions that carry a charge, such as
salts, are more likely to be rejected by the membrane than those that
are not charged, such as organics. The larger the charge and the larger
the particle, the more likely it will be rejected.
GE Water Technologies
www.osmonics.com
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2004