Sciencemadness Discussion Board

Ways to precipitate sodium ions?

Draeger - 12-7-2020 at 03:34

It would be very useful for recycling waste, since that's my usual contaminant.

I wonder if it'd be possible somehow?

clearly_not_atara - 12-7-2020 at 07:04

This is very hard. Ammonium fluorosilicate comes to mind. If uranium (!) is available, Na+ can be precipitated as the triple salt sodium uranyl zinc acetate.

Another possibility is orotic acid:

https://pubs.acs.org/doi/pdf/10.1021/ac50154a050

Draeger - 12-7-2020 at 08:55

Quote: Originally posted by clearly_not_atara  
This is very hard. Ammonium fluorosilicate comes to mind. If uranium (!) is available, Na+ can be precipitated as the triple salt sodium uranyl zinc acetate.

Another possibility is orotic acid:

https://pubs.acs.org/doi/pdf/10.1021/ac50154a050

Woah. I didn't expect it to be that hard. Both fluorine and uranium compounds are far too dangerous for me currently, not to mention the difficulty of finding anything radioactive here.

Orotic acid I haven't looked for yet, but I guess that's my only chance.

Thank you.

CharlieA - 12-7-2020 at 17:37

If you are just wanting to treat your Na ion waste before discarding it, why not just evaporate the waste to dryness and put the waste in a plastic bag and discard it in the trash? I assume that your sodium waste will not contain especially hazardous salts of sodium.

Ubya - 12-7-2020 at 23:18

maybe not precipitate, but you could use a cation absorbing resin to switch Na+ with H+. By later washing the resing with dilute acid you'll get the sodium ions in solution

Whathappensif - 13-7-2020 at 01:24

I was going to suggest an ion exchange resin (e.g. for water softeners) but see that Ubya beat me to it :)

unionised - 13-7-2020 at 01:46

Quote: Originally posted by Ubya  
maybe not precipitate, but you could use a cation absorbing resin to switch Na+ with H+. By later washing the resing with dilute acid you'll get the sodium ions in solution


And an even bigger volume of waste containing sodium ions...
The world produces something like 250 million tons of salt per year.
Your contribution to sodium ion sin waste streams isn't going to be a problem.

Incidentally, while it's not what's usually thought of as a "precipitate" you can sometimes recover sodium sulphate by crystallization, especially if the weather is cold.



outer_limits - 13-7-2020 at 02:33

To be honest, sodium ions are harmless for environment in laboratory scale, and I think that you will waste your money and time (or even health if you'll use a dangerous compound) to reduce it's amount.

If it was mercury or lead (for an instance) you should handle the waste in proper manner. But sodium? Flush it and forget.

Or boil the water, melt precipitate and get sodium metal by electrolysis.

wg48temp9 - 13-7-2020 at 02:40

Quote: Originally posted by Ubya  
maybe not precipitate, but you could use a cation absorbing resin to switch Na+ with H+. By later washing the resing with dilute acid you'll get the sodium ions in solution


Could I wash the resin with a copper salt to convert say sodium hypophosphite to the copper salt assuming the copper salt is soluble?

Ubya - 13-7-2020 at 02:57

Quote: Originally posted by wg48temp9  
Quote: Originally posted by Ubya  
maybe not precipitate, but you could use a cation absorbing resin to switch Na+ with H+. By later washing the resing with dilute acid you'll get the sodium ions in solution


Could I wash the resin with a copper salt to convert say sodium hypophosphite to the copper salt assuming the copper salt is soluble?


not with 100% conversion rate but i think it could be done

wg48temp9 - 13-7-2020 at 03:20

Quote: Originally posted by Ubya  
Quote: Originally posted by wg48temp9  

Could I wash the resin with a copper salt to convert say sodium hypophosphite to the copper salt assuming the copper salt is soluble?


not with 100% conversion rate but i think it could be done


Thanks, I will give it try with water softener resin.

Whathappensif - 13-7-2020 at 03:40

Some bacteria are able to survive in pure water.

Presumably the interior of their cell must be at a higher osmotic pressure to the surrounding fluid. How do these bacteria maintain the osmotic pressure without losing their Na+ ions?

Are there micro-organisms that can work against the osmotic pressure and concentrate Na+ from a hypotonic environment? How do they do it?

Attachment: liao2003.pdf (115kB)
This file has been downloaded 219 times

Draeger - 13-7-2020 at 04:14

I don't want to get rid of the sodium because I'm worried about it getting into nature, I just want to recover other elements that are more expensive than sodium.

Eddie Current - 13-7-2020 at 04:27

Quote: Originally posted by Draeger  
I don't want to get rid of the sodium because I'm worried about it getting into nature.........


I'm pretty sure it came from there in the first place.:P

Ubya - 13-7-2020 at 07:48

Quote: Originally posted by Whathappensif  


Are there micro-organisms that can work against the osmotic pressure and concentrate Na+ from a hypotonic environment? How do they do it?



pretty much all of them do it, you also do it. cells have active transportation mechanisms, the Na-K pump for example, the concentration of Na ions in the cell is much lower than ambient they are in, while it is the opposite for potassium. Chloride ions concentration is also very low inside of cells.

how do bacteria survive in distilled water without exploding? probably it has to do with their cell wall, it is thick and apolar, but my knowledge ends there

clearly_not_atara - 13-7-2020 at 08:48

Quote: Originally posted by Draeger  
I just want to recover other elements that are more expensive than sodium.

In almost all cases you will find it easiest to precipitate the other components rather than sodium. Potassium and lithium can be precipitated by bitartrate and phosphate respectively, but sodium is just the goddamn worst.

Sodium hydrogen oxalate is also relatively insoluble at low temperatures (1-2 wt%). However, practically all other oxalates are also insoluble, so you just precipitate a mixture of oxalates. Not very useful IMHO.

garphield - 13-7-2020 at 09:37

as someone else suggested the solubility of sodium sulfate becomes very low at cold temperatures but this would only work if the stuff you want to recover has a soluble sulfide. in all other cases its probably better to use an ion exchange resin or precipitate out the stuff you want

unionised - 13-7-2020 at 10:34

Quote: Originally posted by wg48temp9  


Could I wash the resin with a copper salt to convert say sodium hypophosphite to the copper salt assuming the copper salt is soluble?

Does hypophosphite reduce copper salts to the metal?

Bedlasky - 13-7-2020 at 13:32

There are few insoluble or sparingly soluble sodium salts:

NaZn(UO2)3(CH3COO)9.6H2O

NaMg(UO2)3(CH3COO)9.6H2O

Na3[AlF6]

Na2[SiF6]

Na[Sb(OH)6]

NaBiO3

Na2U2O7

Na4[Pt3S6]

But these are good for small scale precipitation.
Quote: Originally posted by unionised  
Quote: Originally posted by wg48temp9  


Could I wash the resin with a copper salt to convert say sodium hypophosphite to the copper salt assuming the copper salt is soluble?

Does hypophosphite reduce copper salts to the metal?


I don't know if there is reduction in to the metalic copper, but at least in to Cu(I) yes.

woelen - 14-7-2020 at 05:23

Hypophosphite reduces copper(II) to the hydride, you get fine crystals of CuH, when a solution of a copper salt is treated with a solution of a hypophosphite. This reaction is slow, unless the liquid is gently heated.

wg48temp9 - 14-7-2020 at 07:31

Quote: Originally posted by woelen  
Hypophosphite reduces copper(II) to the hydride, you get fine crystals of CuH, when a solution of a copper salt is treated with a solution of a hypophosphite. This reaction is slow, unless the liquid is gently heated.


I recall a preparation to produce a Copper hypophosphiten(HP) solution using calcium HP and copper sulphate. So if it does decompose it must be slowly as you stated.

The solution can be used to deposit copper tracks on a board when its heated. that's my use.

The decomposition to the hydride occurs in acid solution with some copper depending on the ph.

See Attachment: CuH-fitzsimons1995.pdf (1.1MB)
This file has been downloaded 250 times

I have now found an old thread on SM about copper HP.

symboom - 14-7-2020 at 09:00

Sodium colbaltinitrite is insoluble

Bedlasky - 14-7-2020 at 14:29

Quote: Originally posted by symboom  
Sodium colbaltinitrite is insoluble


Sodium salt is soluble. Potassium is insoluble.