New 2016 product catalogue
PurePro has launched its new website. The website features all of our products listed in our new product catalog and features a comprehensive technical support area.
[ what is reverse osmosis ] [ RO advanced water treatment ] [ RO Renaissance ] [ water from source to tap ] [ water quality problem ] [ treating the water ] [ what make water hard ] [ why is RO better ] [ Japan Nuclear Crisis Affect Drinking Water ] [ 3 Great Reasons To Remineralize Your Pure Water ]
The RO Renaissance:
Why it thrives in the marketplace
Summary: Reverse osmosis often seems like it's been with us forever. With its presence so widespread in the water treatment market, it's a technology that's easily overlooked. Here, the author explains why after five decades, RO is stronger than ever.
Bob Dylan's famous 1960s call to action still
resonates powerfully today, especially in the water
and wastewater treatment industry. But not necessarily
in the water his lyrics suggest. Over the past two
decades, the world's water supply and the technologies
used to treat it have undergone significant changes.
Due to widespread drought conditions, population
growth, urban and suburban sprawl, and an increased
presence of chemical and biological contaminants,
however, the waters aren't growing. They're shrinking
or at least, access to potable water sure is. And the
world is struggling to maintain a pure, potable supply
for both municipal and industrial applications.
According to the World Bank's estimates, by 2025, as
many as 4 billion people or one half of the world's
population could live under conditions of severe water
stress, especially in Africa, the Middle East and
South Asia. One sixth of the World Bank's lending
--approximately $3 billion per year is currently
devoted to water-related projects. In her book, Water
Wars, expert Diane Raines predicts the growing
shortage of clean water threatens to make water, even
more than oil, the cause of political turmoil in the
decades to come.
Salt/brackish water
Adding to the challenge is the fact the majority of
purification technologies typically used for treating
surface and groundwater supplies--while they've become
more economical--still aren't efficient or
cost-effective for desalinating salt water or brackish
water, which are increasingly used as source water for
municipal and industrial applications. Water and
wastewater treatment experts know that change is
necessary if the world's water supply is to support
future development and population growth.
In their search for an efficient solution to the
world's clean water crisis, treatment professionals
have uncovered a purification technology that often
appears to meet their needs better than anything else
on the market. The purification technology now rising
to the surface isn't new, though. It's reverse osmosis
(RO).
First developed in the late 1950s as an economical
method of desalinating seawater, RO uses a
semi-permeable membrane to remove nearly all
particulate matter--turbidity, bacteria,
microorganisms, salts, proteins, asbestos, and even
single molecules of the heavier organics from water.
With pores ranging from 0.0005 to 0.0000002 microns
(um), the membrane "catches" the majority of the
impurities while allowing water to pass through,
creating a purified water product. Of all the commonly
accepted categories of membrane filtration
systems--including RO, nanofiltration, ultrafiltration
and microfiltration--RO removes the smallest sized
particles from water.
Despite the fact that RO membrane filtration has been
recognized as the most effective from of membrane
filtration for some time, it hasn't been widely used
until recently. The reasons are varied but have
typically related, in the past, to high capital and
energy costs and poor efficiency when compared with
other available treatment technologies such as
distillation The higher energy cost arises from the
fact that in order to remove the smallest sized
particles, RO requires a pre-determined level of
pressure on the feed water stream to pass the purified
water through the microscopic pores of the
semi-permeable membrane (see Figure 1). The higher the
number of dissolved solids in the feedwater, the
higher the required amount of operating pressure. The
operating pressures in an RO system can vary from 100
pounds per square inch (psi) or 7 bar to 1,200 psi (83
bar), depending on the type of water to be purified.
Enjoying the spotlight
Today, RO is experiencing a resurgence, thanks to
advanced technology, lower costs and higher water
quality demands. According to a recent study by The
Mcilvaine Co., a consulting and publishing firm, the
U.S. RO modules and equipment market was expected to
exceed $1.3 billion last year. The RO systems market
is growing at an annual rate of 8 percent globally. In
addition, desalination, one of the primary
applications for RO, is expected to grow globally at
an average of 11 percent from now until 2006. Here are
some of the key reasons why this technology is
suddenly back in the spotlight.
Higher water quality standards require more effective
technologies: Increasingly sensitive instruments,
including water quality analyzers, can now measure
parameters such as aluminum, nitrate, nitrite,
ammonia, dissolved oxygen, fluoride, iron, manganese,
phosphate and silica, among other water quality
organics and inorganic contaminants, in the parts per
billion (ppb) range. Because RO is able to remove the
smallest of particles, it coincides with the recent
trend in more accurate instrumentation systems.
Thanks to new technology, the price is right:
According to Bob Mcilvaine, president of the The
Mcilvaine Co., "Reverse osmosis never really fell out
of favor; it just wasn't the most efficient technology
on the market. The big breakthrough today comes
because of higher equipment efficiency, lower
equipment costs and reduced energy usage."
New RO pump technologies are far more energy-efficient
than previous methods: Since RO is a cross-flow
technology, some water passes through the membrane (as
product water) and some flows past it ( as reject
water) carrying away impurities during the process.
The new pumps, which are equipped with energy recovery
devices, use the pressure and the flow of the reject
water to help reduce the size of the pump/motor
assembly required for the system, lowering the power
requirements of the overall plant.
In addition, recent advances with RO membranes that
have higher tolerance to fouling, a higher rejection of
dissolved solids and higher flows, allow plants to
operate a lower costs and higher efficiencies. These
improved membranes require less pre-treatment chemicals,
smaller pump/motor sizes and fewer membrane modules to
achieve the same output. In turn, this creates less
energy waste and a longer membrane life span. This is
key because the membrane component of an RO system can
account for 20-40 percent of the system's complete cost.
The more frequently the membrane needs to be replaced,
the more expensive the system's operational cost
becomes.
And that's not all. With RO costs dropping in recent
years, municipalities can provide a solution quickly
without significantly raising taxes. Coincidentally, the
lower equipment costs and reduced energy usage of RO
comes at the same time that the costs of its most
popular competing purification technology--distillation
--are rising.
"The prices of distillation and RO used to be relatively
similar," said Mcilvaine. But the fuel sources for
distillation have increased in price, and will likely
continue to do so. Since distillation costs are rising
and RO costs are continually dropping, RO is rapidly
becoming the preferable solution for large-scale
purification projects."
Desalination
Unusually prolonged drought conditions have afflicted
the western and southwestern United States, Africa, the
Middle East and South Asia. In addition, increases in
population and industrial waste have led to the release
of a deluge of contaminants into the world's
groundwater. These and other conditions have created an
urgent need for the use of RO systems. A dozen small RO
desalination plants are currently in operation along the
California coast and over 20 more are in development. "
The drought and population growth, not to mention the
proliferation of high-end resort communities in area
that lack adequate water sources, are causing us to
outstrip our available water supply in many parts of the
world," said Mcilvaine. " Increased contamination and
the rise in fuel costs have raised the expense of
purifying water from existing surface sources. Thanks to
the reduction in the operating cost of RO systems,
desalination of sea water has become a much more viable,
affordable option for improving the available water
supply."
Grassroots awareness
Greater public awareness through the media and the U.S.
Environmental Protection Agency has created a sense of
urgency among the public to improve the quality of its
water. The public has greater awareness of
illnesses--ranging from varied cancers to Legionnaire's
disease-that are associated with biological and chemical
contaminants, which can leak form local manufacturing
plants into a community's groundwater.
In addition, the public is aware of RO because of a
surge in residential or point-of-use/point-of-entry (POU/POE)
water treatment systems that are directly available to
them through retailers including Lowe's, Sears and Home
Depot as well as the many U.S. franchise and independent
dealerships across the country The public's increased
use of steadily advancing home water treatment
technologies has sensitized them to water quality issues
at the municipal, regional and global levels.
The consumer public has proved that water quality is a
key concern, and that they're willing to pay extra for
non-municipal sources of drinking water. Bottled water
is now second only to soft drinks as the largest-selling
beverage type globally. Brackish groundwater and highly
chlorinated municipal water sources, both of which lead
to poor water taste, have led the public to demand
better water quality standards and a better drinking
alternative. By using the newly cost-and
energy-efficient RO technologies, bottled water
companies can more easily provide the product at
increased profits. And consumers-residential or
business-who have RO installed in their homes or offices
can have virtually the same quality water available to
them at the tap. The drought and population growth, not
to mention the proliferation of high-end resort
communities in areas that lack adequate water sources,
are causing us to outstrip our available water supply in
many parts of the world.
Conclusion
Thanks to the newfound effectiveness and performance of
RO, Bob Dylan's famous lyrics might be prophetic after
all. If municipalities and industries around the world
can cost effectively use RO for desalination and other
options to better combat the looming water crisis, the
waters around us might indeed grow. Meanwhile, the
nations of the world will be able to provide clean,
potable water to their populations for years to come.
The times, indeed, may be a changin'.