Chemists Work to Desalt the Ocean for Drinking Water, One Nanoliter at a Time

[East Coast Pirate]

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.

-snip-

“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.”

-snip-

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.


The left panel shows the salt (which is tagged with a fluorescent tracer) flowing upward after a voltage is applied by an electrode (the dark rectangle) jutting into the channel at just the point where it branches. In the right panel no voltage is being applied.


More: http://www.utexas.edu/news/2013/06/27/chemists-work-to-desalt-the-ocean-for-drinking-water-one-nanoliter-at-a-time/

[MADem]

1. Make the desert bloom!!!! nt

[HereSince1628]

4. Suggest a new technology and one of the first goals for it is destroy an ecosystem?

Interesting, and based on human history, very VERY human.

[MADem]

5. Well, the desert USED to bloom until people cut down all the trees and burned them up.

I'm proposing it be returned to its previous state.

You got a gripe with that, too?

Sheesh.

Any advancements that serve to feed the hungry work for me--I guess that does make me "very, very human" indeed.

[East Coast Pirate]

8. I agree with you on this one.

This isn't like cutting or burning down a rainforest where you're wiping out thousands of plants and animals. It's a big desert.

Internet flame war in...

[HereSince1628]

10. The Historical Roots of Our Ecological Crisis

I'll not make an argument at all, but rather link to one that still holds, from the first handbook for environmental teach-ins on the very first Earth Day...


www.uvm.edu/~gflomenh/ENV-NGO-PA395/articles/Lynn-White.pdf

[MADem]

11. All forms of life modify their contexts.

I don't think Christianity is the answer, though. Emission-free cars and clean water are a good start, though.

[HereSince1628]

12. The point isn't christianity, but that ecological crises follow from the hubris of anthropocentrism

so deeply embedded within our culture that it is included in our religious traditions.

[MADem]

13. Well, bringing water to agrarian societies who suffer routinely at the hands of drought

is something I can get behind. I don't think leaving people to die when you can solve their problem is any smarter than sticking with horses as a principal form of transport because once upon a time, that was the paradigm.

Make the damn desert bloom, I say.

[PuffedMica]

2. good stuff

http://www.democraticunderground.com/112747966

[East Coast Pirate]

3. You think I should peruse every DU group before I post something?

[MADem]

6. That doesn't apply anywhere but LBN.

Thank you for posting this, I would not have seen it otherwise.

[East Coast Pirate]

7. You're welcome.

Since it involves the environment and science I think it applies to both groups. It's a goofy thing to be a smartass about.

[mopinko]

9. pretty cool. seems like it ought to run well on solar, too.

i think this is so important to tackle. after all, we are gonna have more seawater than we know what to do with. when miami starts going under, maybe we can start recharging all the aquifers we drained.

wonder if a similar device would also remove pollutants.

[Sunlei]

14. very cool!! what to do with the brine/salt?

The leftover brine water would be very toxic. There are a lot of different minerals, even rare earths that could be used.

I was hoping any desalination process would seperate the usefull minerals. At the least leave a hard block of salt/minerals, that could be processed/coated? used as building material.

Large scale desalination would have a lot of brine byproduct.

[Wounded Bear]

15. Very important stuff!

They say that water is the next resource people will fight wars over, and it's already starting, really.