Salt Water

UCLA FIRSTS Every other Friday, The Bruin will
highlight social, political and scientific advancements that
originated at UCLA and set standards for both the university and
the nation.

By Marjorie Hernandez
Daily Bruin Contributor

In the midst of the Cold War, President John F. Kennedy spoke of
“New Frontiers,” in the field of space exploration. At
the same time, researchers at UCLA’s School of Engineering
and Applied Sciences looked to the ocean as their new frontier.

Following the slogan “go to the moon and make the desert
bloom,” the researchers made significant progress in water
treatment, according to the engineering school’s Web
site.

Recognizing a need for more water both in California and around
the world, these scientists searched for a way to convert salt
water into a drinkable source. Although earlier methods for
desalinization, the process of removing salt from ocean water, were
developed in the late 1940s, they proved to be inefficient and
costly.

But, Joseph McCutchan, an engineering professor at UCLA who
worked on the desalinization process, said money should be no
object when it comes to water purification.

“It’s not a question of cost when you need
it,” he said in an interview with the Los Angeles
Herald-Examiner in 1977.

From their observation of osmosis, the diffusion of water from
higher to lower concentrations, UCLA researchers found they could
apply the concept to desalinization.

Illustration by JASON CHEN/Daily Bruin Senior Staff They found
that when salt water and fresh water are placed on opposite sides
of a thin film membrane, fresh water will naturally flow to the
salt water.

But with reverse osmosis, applied pressure pushes water
molecules back through tiny membrane holes, leaving salt deposits
behind.

In 1960, UCLA engineering Professor Samuel T. Yasser and
graduate students Sidney Loeb and Srinivasa Sourirajan,
successfully developed the first demonstration of reverse osmosis
with a synthetic membrane, or filter.

The membrane, based on earlier work by UCLA engineering
Professor Gerald L. Hassler’s research, contained tiny holes
which allowed water molecules to pass though.

“It was a start towards a very valuable tool,” said
associate professor of civil and environmental engineering Thomas
Harmon. “It’s helped drinking water treatment
immensely.”

In 1965, the discovery of the UCLA researchers led to the
development of the first reverse osmosis plant in Coalinga, a small
town sixty miles southwest of Fresno. At that time, the Coalinga
desalinization plant produced up to 6,000 gallons of ground water
per day.

Before that, Coalinga’s drinking water was imported from
other wells and shipped in tank cars for distribution.

Another plant in La Jolla focused on converting salt water,
which is 15 times saltier than ground water, into fresh water.

Developments in membrane technology continue today, due in a
large part to the contribution of UCLA pioneers.

Since the sixties, filters with different configurations and
materials have been developed out of the original Hassler
membrane.

“The reverse osmosis membrane started a whole new avenue
of tailored fabrication of filters that do different things for
water treatment,” Harmon said.

“All those things started to grow once reverse osmosis was
demonstrated,” he continued.

Technology from the reverse osmosis discovery has spread
worldwide, giving birth to desalinization plants throughout the
Middle East and North Africa where need is high.

Although filters are not as expensive as they were in the past,
maintenance costs have prevented local cities from abandoning the
more commonly used method of importing water.

Even with Southern California’s relatively dry climate and
desert areas, water distributors have opted to use other methods to
transport its water.

Currently, Los Angeles receives about half of its water supply
from the Owens River Aqueduct which transports melted snow from the
eastern slopes of the Sierra Nevada, according to the LA Department
of Water and Power.

Local groundwater only accounts for 15 percent of the
city’s total water supply.

The remaining supply is bought from the Metropolitan Water
District of Southern California, the regional water
“wholesaler” whose sources include the Colorado River
Aqueduct.

But according to Harmon, reverse osmosis is now mostly used in
the “polishing” or final steps in the purification of
waste water.

Waste water from agricultural irrigation sites, washers and
toilets are purified and placed back into the hydrological
cycle.

“As our population gets more and more crowded, we have to
be better about recycling our water,” Harmon said. “We
can’t just use it and throw it out anymore.”

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