Electrolytical removal of Na and Cl ?

[Externet]

Hi.

 

Electrolysis on salty water accumulates dissolved ions at the electrodes, as far as I know.

After all the ions have attached/combined/bubbled/removed at the electrodes, what happens ?

Is the water still 'conductive' ?

 

Is there a precise voltage that does NOT dissociate H2 and O2 and leave the water unchanged and only remove the dissolved salt ions ?

Or, how can the electrolytic process/electrodes be tailored to remove only ions and leave reasonably pure water ?

 

Miguel

[gonelli]

Is there a precise voltage that does NOT dissociate H2 and O2 and leave the water unchanged and only remove the dissolved salt ions ?

Miguel

 

If you apply a voltage that is less than around 2.60 V then theoretically you shouldn't get H2 or O2 being produced at the electrodes. But I'm not sure about what will happen with the movement of the ions.

[hermanntrude]

Hi.

 

Electrolysis on salty water accumulates dissolved ions at the electrodes, as far as I know.

After all the ions have attached/combined/bubbled/removed at the electrodes, what happens ?

Is the water still 'conductive' ?

 

Is there a precise voltage that does NOT dissociate H2 and O2 and leave the water unchanged and only remove the dissolved salt ions ?

Or, how can the electrolytic process/electrodes be tailored to remove only ions and leave reasonably pure water ?

 

Miguel

 

nope. Doesn't work like that.

 

Gonelli, you'll always get hydrogen but you might get chlorine instead of oxygen or mixed with it, depending on the concentration of chloride ions and the voltage used. You will NEVER get sodium this way.

 

link: http://www.scienceforums.net/forum/showthread.php?t=40177

[Mr Skeptic]

What they do to get sodium and chlorine is conduct electrolysis on melted salt (which is very hot if you were wondering).

[Externet]

Zero interest in this thread for sodium. Just wondering if any electrical method is applicable for desalination instead of evaporation/osmosis

[Mr Skeptic]

Using electrolysis for desalination (it it were possible) would be less efficient than removing the impurities without splitting them nor the water apart.

[John Cuthber]

It's possible

http://en.wikipedia.org/wiki/Electrodialysis

[Externet]

Nice !. Thanks, John.

 

The 'Applications' paragraph in your link shows "Large scale brackish and seawater desalination and salt production"

 

If the membranes could be made at low cost -not medical grade$- and not as expensive as reverse osmosis membranes; seawater could have some better drip irrigation potential. Am assuming high pressures would not be needed

Now, what do they consist of ? Any hyperfancy material$ ?

 

Google is showing results for "electrodialysis desalination" ... time to read.

 

But I know no german:

http://www.pca-gmbh.com/appli/ed.htm

Edited November 25, 2009 by Externet

[virushacker]

actually you can get sodium through this way but it will quickly react with the water and produce hydrogen gas and sodium hydroxide

Edited January 5, 2010 by virushacker

[John Cuthber]

actually you can get sodium through this way but it will quickly react with the water and produce hydrogen gas and sodium hydroxide

 

Actually, you can't.

[Externet]

Very old thread, resurrected as I found something pertinent claiming an electronic method for desalination.

 

- The use of the term "mediated" -what does it mean ?

- If works in such small scale, what could prevent from making bigger ones instead of paralleling many tiny ones ?

 

----> http://www.ideaconnection.com/new-inventions/waterchip-provides-cheap-effective-desalination-08434.html