Reverse Osmosis
Reverse osmosis (RO) is the most
economical method of removing 90% to 99% of all contaminants. The pore
structure of RO membranes is much tighter than UF membranes.
RO membranes are capable of rejecting
practically all particles, bacteria and organics >300 daltons (another name for atomic mass unit) molecular
weight (including pyrogens).
In fact, reverse osmosis technology is
used by most leading water bottling plants. Natural osmosis occurs when
solutions with two different concentrations are separated by a semi-permeable
membrane.
Osmotic pressure drives water through the membrane; the water dilutes
the more concentrated solution; and the end result is an equilibrium.
In water purification systems,
hydraulic pressure is applied to the concentrated solution to counteract the
osmotic pressure. Pure water is driven from the concentrated solution and
collected downstream of the membrane.
Because RO membranes are very
restrictive, they yield slow flow rates. Storage tanks are required to produce
an adequate volume in a reasonable amount of time.
RO also involves an ionic exclusion
process. Only solvent is allowed to pass through the semi-permeable RO
membrane, while virtually all ions and dissolved molecules are retained
(including salts and sugars).
The semi-permeable membrane rejects
salts (ions) by a charge phenomena action: the greater the charge, the greater
the rejection.
Therefore, the membrane rejects nearly
all (>99%) strongly ionized polyvalent ions but only 95% of the weakly
ionized monovalent ions like sodium.
Reverse osmosis is highly effective in
removing several impurities from water such as total dissolved solids (TDS), turbidity,
asbestos, lead and other toxic heavy metals, radium, and many dissolved organics.
The process will also remove
chlorinated pesticides and most heavier-weight Volatile Organic Compounds.
Volatile Organic Compounds (VOCs) are a
large group of carbon-based chemicals that easily evaporate at
room temperature,
like acetone, benzene, ethylene glycol and formaldehyde.
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| Multi-Media Filter, Highly-Activated Carbon Filter, Zeolite-Process Water Softener with Brine Tank, Reverse Osmosis Module (fully automatic backwash & regeneration) |
Reverse osmosis and activated carbon
filtration are complementary processes. Combining them results in the most
effective treatment against the broadest range of water impurities and
contaminants.
Reverse osmosis is the most economical
and efficient method for purifying tap water if the system is properly designed
for the feed water
conditions
and the intended use of the product water.
Reverse osmosis is also the optimum
pretreatment for reagent-grade water polishing systems.
In addition, Reverse osmosis treatment
is an insurance policy against nuclear radiation such as radioactive plutonium
or strontium in the drinking water.
If one lives near a nuclear power
plant, this is a key way to ensure the household is drinking the best water for
their health.
Table 6. Reverse Osmosis
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Advantages
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Disadvantages
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·
Effectively removes all types of
contaminants to some extent (particles, pyrogens, microorganisms, colloids
and dissolved inorganics)
·
Requires minimal maintenance.
·
· pyrogens
- A fever- inducing agent; ·
pyrogens are produced by bacteria, molds, viruses, and yeasts
·
Colloids are
mixtures whose particles are larger than the size of a molecule but
smaller than particles that can be seen with the naked eye. Colloids are one
of three major types of mixtures, the other two being solutions and
suspensions.
|
·
Flow rates are usually limited to a
certain gallons/day rating.
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source: freedrinkingwater.com
Thank you for sharing this blog. The human body consist of 60% of water. Water is essential for good health and our body functions such as temperature regulation, cellular function and waste removal. Waterlily domestic 10 ltr ro water purifier helps to take a pure water.
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