Featured Research

from universities, journals, and other organizations

Better desalination technology key to solving world's water shortage

Date:
August 5, 2011
Source:
Yale University
Summary:
Over one-third of the world's population already lives in areas struggling to keep up with the demand for fresh water. By 2025, that number will nearly double. A new Yale University study argues that seawater desalination should play an important role in helping combat worldwide fresh water shortages -- once conservation, reuse and other methods have been exhausted -- and provides insight into how desalination technology can be made more affordable and energy efficient.

Over one-third of the world's population already lives in areas struggling to keep up with the demand for fresh water. By 2025, that number will nearly double. Some countries have met the challenge by tapping into natural sources of fresh water, but as many examples -- such as the much-depleted Jordan River -- have demonstrated, many of these practices are far from sustainable.

Related Articles


A new Yale University study argues that seawater desalination should play an important role in helping combat worldwide fresh water shortages -- once conservation, reuse and other methods have been exhausted -- and provides insight into how desalination technology can be made more affordable and energy efficient.

"The globe's oceans are a virtually inexhaustible source of water, but the process of removing its salt is expensive and energy intensive," said Menachem Elimelech, a professor of chemical and environmental engineering at Yale and lead author of the study, which appears in the Aug. 5 issue of the journal Science.

Reverse osmosis -- forcing seawater through a membrane that filters out the salt -- is the leading method for seawater desalination in the world today. For years, scientists have focused on increasing the membrane's water flux using novel materials, such as carbon nanotubes, to reduce the amount of energy required to push water through it.

In the new study, Elimelech and William Phillip, now at the University of Notre Dame, demonstrate that reverse osmosis requires a minimum amount of energy that cannot be overcome, and that current technology is already starting to approach that limit. Instead of higher water flux membranes, Elimelech and Phillip suggest that the real gains in efficiency can be made during the pre- and post-treatment stages of desalination.

Seawater contains naturally occurring organic and particulate matter that must be filtered out before it passes through the membrane that removes the salt. Chemical agents are added to the water to clean it and help coagulate this matter for easier removal during a pre-treatment stage. But if a membrane didn't build up organic matter on its surface, most if not all pre-treatment could be avoided, according to the scientist's findings.

In addition, Elimelech and Phillip calculate that a membrane capable of filtering out boron and chloride would result in substantial energy and cost savings. Seventy percent of the world's water is used in agriculture, but water containing even low levels of boron and chloride -- minerals that naturally occur in seawater -- cannot be used for these purposes. Instead of removing them during a separate post-treatment stage, the scientists believe a membrane could be developed that would filter them more efficiently at the same time as the salt is removed.

Elimelech cautions that desalination should only be considered a last resort in the effort to provide fresh water to the world's populations and suggests that long-term research is needed to determine the impact of seawater desalination on the aquatic environment, but believes that desalination has a major role to play now and in the future.

"All of this will require new materials and new chemistry, but we believe this is where we should focus our efforts going forward," Elimelech said. "The problem of water shortage is only going to get worse, and we need to be ready to meet the challenge with improved, sustainable technology."


Story Source:

The above story is based on materials provided by Yale University. Note: Materials may be edited for content and length.


Journal Reference:

  1. Menachem Elimelech, William A. Phillip. The Future of Seawater Desalination: Energy, Technology, and the Environment. Science, 5 August 2011: Vol. 333 no. 6043 pp. 712-717 DOI: 10.1126/science.1200488

Cite This Page:

Yale University. "Better desalination technology key to solving world's water shortage." ScienceDaily. ScienceDaily, 5 August 2011. <www.sciencedaily.com/releases/2011/08/110804141752.htm>.
Yale University. (2011, August 5). Better desalination technology key to solving world's water shortage. ScienceDaily. Retrieved December 21, 2014 from www.sciencedaily.com/releases/2011/08/110804141752.htm
Yale University. "Better desalination technology key to solving world's water shortage." ScienceDaily. www.sciencedaily.com/releases/2011/08/110804141752.htm (accessed December 21, 2014).

Share This


More From ScienceDaily



More Earth & Climate News

Sunday, December 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Lava on Track to Hit Hawaii Market

Raw: Lava on Track to Hit Hawaii Market

AP (Dec. 19, 2014) Lava from an active volcano on Hawaii's Big Island slowed slightly but stayed on track to hit a shopping center in the small town of Pahoa. (Dec. 19) Video provided by AP
Powered by NewsLook.com
Birds Might Be Better Meteorologists Than Us

Birds Might Be Better Meteorologists Than Us

Newsy (Dec. 19, 2014) A new study suggests a certain type of bird was able to sense a tornado outbreak that moved through the U.S. a day before it hit. Video provided by Newsy
Powered by NewsLook.com
Navy Unveils Robot Fish

Navy Unveils Robot Fish

Reuters - Light News Video Online (Dec. 18, 2014) The U.S. Navy unveils an underwater device that mimics the movement of a fish. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com
Arctic Warming Twice As Fast As Rest Of Planet

Arctic Warming Twice As Fast As Rest Of Planet

Newsy (Dec. 18, 2014) The Arctic is warming twice as fast as the rest of the planet, thanks in part to something called feedback. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

More Coverage


New Paper Examines Future of Seawater Desalinization

Aug. 4, 2011 Researchers have made a critical review of the state of seawater desalination ... read more

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins