UCLA researchers say they have developed a new way to convert
salt water to fresh water that will be more cost-efficient than
current methods.
Eric Hoek, a professor of civil and environmental engineering,
and his team of researchers at the Henry Samueli School of
Engineering and Applied Sciences announced Nov. 5 that they have
developed a reverse osmosis membrane that will drastically reduce
energy consumption in desalinization and water reclamation
procedures.
Water reclamation uses the same technical processes as
desalinization, but purifies waste water into drinkable fresh
water.
Hoek said his team created a new type of membrane, the first
major membrane innovation in the water-treatment industry in nearly
40 years, which will require about half as much energy as do
current methods to produce fresh water, with an overall cost
reduction of up to 30 percent.
“The need for a sustainable, affordable supply of clean
water is a key priority for our nation’s future and
especially that of California ““ the fifth-largest economy in
the world,” Hoek said in the press release from the Samueli
School.
“It is essential that we reduce the cost of desalination
““ including energy demand and environmental issues ““
before a major drought occurs and we lack the ability to
efficiently and effectively increase our water supply,” he
said.
Reverse osmosis, a term first coined by a UCLA researcher in the
1940s, is a procedure that uses water pressure to push water
molecules through pores in a semi-permeable membrane too small to
allow the passage of salts and other impurities. Through this
process, salt or waste water can be converted into fresh water.
Hoek said existing reverse osmosis membranes tend to condense
over time, which means more energy must be exerted to purify the
water. They are also subject to “fouling,” creating
buildup of bacteria and other impurities outside the membrane. Hoek
added that fixing these problems can be expensive.
The membrane Hoek and his team created has particles embedded in
it that attract water, which helps direct the flow of water through
the membrane. These particles help resist the fouling and
condensing of the membrane.
This is considered a “major innovation” by the
reverse osmosis industry, Hoek said, as it makes the membrane 10
times more permeable and reduces the energy consumption by
one-half.
More efficient desalination and water reclamation would help
relieve California’s water concerns, Hoek said, such as the
need to replenish aquifers, preventing sea water from intruding
into drinking supplies, and agricultural needs.
Hoek said he believes water reclamation will become more
prevalent in establishing viable water sources in the future in the
U.S. He added that reclaiming water is much less energy intensive
than either desalinizing seawater or importing fresh water.
Anna Jawor, a doctoral student from Poland who worked on the
testing of the membrane, said she was surprised at the scarcity of
viable water sources in Southern California when she first
arrived.
“Here you must either transport water from the North, or
Arizona or desalinize seawater,” she said. “You begin
to see how important it is to work on this technology.”
Hoek says they are aiming to make their patent-pending membrane
commercially available by the end of 2007 through NanoH2O, LLP, a
company he helped found. They will be piloting their model with a
private company to put the commercially viable technology into
effect.
Though Hoek said he understands that there are technological
issues associated with desalination and water reclamation to
consider, such as energy consumption and economic effects, he
believes it is an option that must eventually be actualized in the
U.S.
“A lot of people are afraid that if we pursue it, we will
have an unlimited water supply, and we will see a huge growth in
population,” he said. “But there are other factors to
consider. I don’t think this will be the key to open
Pandora’s box.”
Jawor said the innovation has possibilities for other nations.
“If we can start solving problems here, maybe we can help
other areas with their water,” she said.