The new method requires so little energy that it can run on a store-bought battery.
By creating a small electrical field that removes salts from seawater, chemists at The University of Texas at Austin and the University of Marburg in Germany have introduced a new method for the desalination of seawater that consumes less energy and is dramatically simpler than conventional techniques. The new method requires so little energy that it can run on a store-bought battery.
The process evades the problems confronting current desalination methods by eliminating the need for a membrane and by separating salt from water at a microscale.
The technique, called electrochemically mediated seawater desalination, was described last week in the journal Angewandte Chemie. The research team was led by Richard Crooks of The University of Texas at Austin and Ulrich Tallarek of the University of Marburg. It’s patent-pending and is in commercial development by startup company Okeanos Technologies.
“The availability of water for drinking and crop irrigation is one of the most basic requirements for maintaining and improving human health,” said Crooks, the Robert A. Welch Chair in Chemistry in the College of Natural Sciences. “Seawater desalination is one way to address this need, but most current methods for desalinating water rely on expensive and easily contaminated membranes. The membrane-free method we’ve developed still needs to be refined and scaled up, but if we can succeed at that, then one day it might be possible to provide fresh water on a massive scale using a simple, even portable, system.”
This new method holds particular promise for the water-stressed areas in which about a third of the planet’s inhabitants live. Many of these regions have access to abundant seawater but not to the energy infrastructure or money necessary to desalt water using conventional technology. As a result, millions of deaths per year in these regions are attributed to water-related causes.
“People are dying because of a lack of freshwater,” said Tony Frudakis, founder and CEO of Okeanos Technologies. “And they’ll continue to do so until there is some kind of breakthrough, and that is what we are hoping our technology will represent.”
To achieve desalination, the researchers apply a small voltage (3.0 volts) to a plastic chip filled with seawater. The chip contains a microchannel with two branches. At the junction of the channel an embedded electrode neutralizes some of the chloride ions in seawater to create an “ion depletion zone” that increases the local electric field compared with the rest of the channel. This change in the electric field is sufficient to redirect salts into one branch, allowing desalinated water to pass through the other branch.
“The neutralization reaction occurring at the electrode is key to removing the salts in seawater,” said Kyle Knust, a graduate student in Crooks’ lab and first author on the paper.
Like a troll at the foot of the bridge, the ion depletion zone prevents salt from passing through, resulting in the production of freshwater.
Thus far Crooks and his colleagues have achieved 25 percent desalination. Although drinking water requires 99 percent desalination, they are confident that goal can be achieved.
“This was a proof of principle,” said Knust. “We’ve made comparable performance improvements while developing other applications based on the formation of an ion depletion zone. That suggests that 99 percent desalination is not beyond our reach.”
The other major challenge is to scale up the process. Right now the microchannels, about the size of a human hair, produce about 40 nanoliters of desalted water per minute. To make this technique practical for individual or communal use, a device would have to produce liters of water per day. The authors are confident that this can be achieved as well.
The Latest Bing News on:
Desalt the Ocean
- California Coastal Commission weighs disputed Orange County desalination planton November 13, 2013 at 6:44 am
"There's just lots of competing interests for imported water," Kennedy said. "If you can desalt the ocean in your backyard, you need to look at that very closely." ...
The Latest Google Headlines on:
Desalt the Ocean
The Latest Bing News on:
- Antioch Desalination Plant: City Takes Out $15M Line Of Crediton November 28, 2020 at 2:31 am
Once construction starts on the Antioch Brackish Water Desalination Project, it should take two years to complete.
- Seawater Desalination Equipment Market Size 2020: Global Analysis, Industry Growth, Current Trends and Forecast till 2025on November 26, 2020 at 5:46 pm
Market Demand, Growth, Opportunities, Manufacturers and Analysis of Top Key Players to 2025" To Its Research Database. The global water desalination equipment market size is anticipated to reach USD ...
- City Council Approves Signing Of Credit Line For Desalination Projecton November 26, 2020 at 7:55 am
The Antioch City Council on Tuesday night approved signing a new $15 million line of credit for the construction of a desalination plant to treat brackish water drawn from the San Joaquin River.
- Beer maker backs India solar desalination plant to boost water, jobs for womenon November 26, 2020 at 5:23 am
(Thomson Reuters Foundation) - A water desalination plant powered by solar energy in a small east Indian town, backed by beer maker Carlsberg Group, could be a sustainable option for other coastal ...
- Beer maker backs India solar desalination plant to boost water, jobs for womenon November 26, 2020 at 2:00 am
The solar-powered plant, part of Carlsberg's water conservation plan, could be a model to improve water supplies in coastal communities and provide local work ...
- $15 million credit line will help Antioch build desalination planton November 25, 2020 at 7:58 am
Antioch’s plan to build a desalination plant to clear up the city’s brackish water got another boost this week when the City Council unanimously approved $15 million in interim financing. The almost ...
- Mumbai: Desalination to ease water stress, raise green concernson November 25, 2020 at 7:51 am
Mumbai's water need is now 4,200 MLD (million litres per day), expected to rise by 71% by 2041 MUMBAI: The state government has green-lighted a desalination plant at Manori to meet the city's ...
- What are Desalination plants?on November 25, 2020 at 4:59 am
On 23 November 2020, Uddhav Thackeray led Maharashtra Government gave a go-ahead to the Brihanmumbai Municipal Corporation (BMC) for setting up of a desalination plant in Mumbai's Manori to ...
- Global Desalination Pumps Market 2020-2024: Size, Share, Emerging Trends, Demand, Revenue and Forecasts Researchon November 23, 2020 at 6:55 pm
Global “Desalination Pumps Market ” report presents a complete overview, market shares, and growth opportunities of ...
- Desalination Pumps Market Size 2020 Industry Demand, Share, Trend, Industry News, Growth, Top Key Players, Business Statistics and Forecast to 2026on November 20, 2020 at 8:57 pm
Final Report will add the analysis of the impact of COVID-19 on this industry." Global “Desalination Pumps Market” ...