Anion resin charging just by sitting on the counter?

[pdxmonkeyboy]

I had a quick question. I am on well water and blast through a ton of anion resin. A full canister lasts me about 100 gallons. Anyways, its not a big deal as I have two of them inline and cation and mixed resin beds as well and just recharge them with lye.

What is interesting though is that I had about.. 8 or 9 cups of exhausted yellow resin in a tupperware waiting until I recharge everything and over a week of just sitting there it turned back blue. Any idea why it would do that?

 

[Randy Holmes-Farley]

I'm not sure if the process is simple equilibration of CO2, or something related to drying and possibly CO2 at the same time, or even something else involving very slow release of deeply buried hydroxide in the beads slowly coming up to depleted areas where the color has changed, switching it back.

If you have substantial carbon dioxide in your well water, it will bind to the anion resin, depleting it and leaving lots of CO2 on it.

If you leave new (charged) resin open to the air, CO2 can enter it and deplete it.

While I have not seen it happen, if you have used resin loaded with lots of CO2, some of that CO2 may come off into equilibrium with the air, and if enough comes off that the pH rises in the resin, the color may change.

 

[pdxmonkeyboy]

Thanks Randy. So you believe it is off gassing CO2? I think my well water has lots of carbonate or lots of silicates.

 

[Randy Holmes-Farley]

Thanks Randy. So you believe it is off gassing CO2? I think my well water has lots of carbonate or lots of silicates.

Carbonate will off gas as CO2. Silicate shouldn't come off.

It's just a theory, but it is plausible.