Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Drinking Water from the Sea

27.06.2013
Electrochemically mediated seawater desalination in microfluidic systems

A new method for the desalination of sea water has been reported by a team of American and German researchers in the journal Angewandte Chemie. In contrast to conventional methods, this technique consumes little energy and is very simple. This electrochemically mediated seawater desalination is based on a system of microchannels and a bipolar electrode.



The United Nations estimates that one-third of the global population already lives in water-stressed areas; this figure is expected to double by 2025. Salt water, on the other hand, is not in short supply. A seemingly obvious solution would be to desalinate seawater; however, this is not so easy. Processes like vaporization and subsequent condensation of the water require enormous amounts of energy. Reverse osmosis additionally requires expensive, delicate membranes that are easily fouled, and the water must undergo complex pre-treatment steps.

Developed with the support of the U.S. Department of Energy by Richard M. Crooks (The University of Texas at Austin), Prof. Ulrich Tallarek (University of Marburg, Germany), and their colleagues, the new electrochemical process works without membranes or large amounts of energy. The researchers force the water through a system of two microchannels that are about 22 µm wide, an auxiliary channel and a branched working channel, flowing on to the outlets.

The two channels are electrically connected through a bipolar electrode. The auxiliary channel is connected to a voltage source, the working channel is grounded, and a potential difference of 3.0 V is established between the two channels.

The structure of the channel system is critical: The electrode juts into the branch point of the working channel. Because of the voltage, some of the negatively charged chloride ions in the seawater are oxidized to neutral chlorine at one end of the bipolar electrode. In the narrow channel system, this creates a zone that has a lower number of negatively charged ions, which results in an electric field gradient that directs the positively charged ions in the seawater into the branching channel.

Physics requires the electroneutrality within the microchannels to be maintained, so the anions follow the positive ions into the branched channel. The water flowing through the branch is thus enriched with ions, while the water continuing through the main working channel is partially desalinated.

The amount of energy required for this new technique is so low that the system can operate with a simple battery. In contrast to reverse osmosis, it is only necessary to remove sand and sediment from the seawater. No further treatment, disinfection, or addition of chemicals is needed. A simple parallel arrangement of many microchannel systems should allow for an increase in water throughput.
About the Author
Dr. Richard M. Crooks is the Robert A. Welch Chair in Materials Chemistry at The University of Texas at Austin. His research interests in electrochemistry, microfluidics, biosensing, and catalysis.
Author: Richard M. Crooks, The University of Texas at Austin (USA), http://rcrooks.cm.utexas.edu/research/
Title: Electrochemically Mediated Seawater Desalination
Angewandte Chemie International Edition, Permalink to the article: http://dx.doi.org/10.1002/anie.201302577

Richard M. Crooks | Angewandte Chemie
Further information:
http://pressroom.angewandte.org

More articles from Life Sciences:

nachricht Even plants can be stressed
03.09.2015 | Max-Planck-Institut für Molekulare Pflanzenphysiologie

nachricht Research team from Münster develops innovative catalytic chemistry process
03.09.2015 | Westfälische Wilhelms-Universität Münster

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fraunhofer ISE Develops Highly Compact Inverter for Uninterruptible Power Supplies

Silicon Carbide Components Enable Efficiency of 98.7 percent

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE have developed a highly compact and efficient inverter for use in uninterruptible power...

Im Focus: How wind sculpted Earth's largest dust deposit

China's Loess Plateau was formed by wind alternately depositing dust or removing dust over the last 2.6 million years, according to a new report from University of Arizona geoscientists. The study is the first to explain how the steep-fronted plateau formed.

China's Loess Plateau was formed by wind alternately depositing dust or removing dust over the last 2.6 million years, according to a new report from...

Im Focus: An engineered surface unsticks sticky water droplets

The leaves of the lotus flower, and other natural surfaces that repel water and dirt, have been the model for many types of engineered liquid-repelling surfaces. As slippery as these surfaces are, however, tiny water droplets still stick to them. Now, Penn State researchers have developed nano/micro-textured, highly slippery surfaces able to outperform these naturally inspired coatings, particularly when the water is a vapor or tiny droplets.

Enhancing the mobility of liquid droplets on rough surfaces could improve condensation heat transfer for power-plant heat exchangers, create more efficient...

Im Focus: Increasingly severe disturbances weaken world's temperate forests

Longer, more severe, and hotter droughts and a myriad of other threats, including diseases and more extensive and severe wildfires, are threatening to transform some of the world's temperate forests, a new study published in Science has found. Without informed management, some forests could convert to shrublands or grasslands within the coming decades.

"While we have been trying to manage for resilience of 20th century conditions, we realize now that we must prepare for transformations and attempt to ease...

Im Focus: OU astrophysicist and collaborators find supermassive black holes in quasar nearest Earth

A University of Oklahoma astrophysicist and his Chinese collaborator have found two supermassive black holes in Markarian 231, the nearest quasar to Earth, using observations from NASA's Hubble Space Telescope.

The discovery of two supermassive black holes--one larger one and a second, smaller one--are evidence of a binary black hole and suggests that supermassive...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Together - Work - Experience

03.09.2015 | Event News

Networking conference in Heidelberg for outstanding mathematicians and computer scientists

20.08.2015 | Event News

Scientists meet in Münster for the world’s largest Chitin und Chitosan Conference

20.08.2015 | Event News

 
Latest News

Lighter with Laser Welding

03.09.2015 | Process Engineering

For 2-D boron, it's all about that base

03.09.2015 | Materials Sciences

Phagraphene, a 'relative' of graphene, discovered

03.09.2015 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>