Regeneration of DI resin?

[JenDub]

Hey Randy,

I've got a fun one for you; is it feasible to regenerate DI resin at home? I realize that it would probably need to be seperate Cati & Ani beds rather than a mixed since each resin requires a different flush. I'm not too hep on the idea of dealing with hydrochloric acid at home (very clumsy + acid = ouch!), nor do I know where to obtain it.

Here is an article I read on the matter:
http://www.watertechonline.com/article.asp?IndexID=6634211

Any wisdom on the matter is much appreciated!

[Randy Holmes-Farley]

Some folks do recharge their own resins, and if resin cost is a major factor and you do not mind handling chemicals, it is a fine plan. For me personally, I do not think it worth my time to bother.

I discuss it briefly here:

Reverse Osmosis/Deionization Systems to Purify Tap Water for Reef Aquaria
http://reefkeeping.com/issues/2005-05/rhf/index.htm

specifically here:

http://www.reefkeeping.com/issues/2005-05/rhf/index.php#9

Recharging DI Resins

When DI resins are present as mixed bed filters, they are essentially one-time use devices that must be thrown away when depleted. These are the types supplied with many commercial RO/DI systems, and are what I use. Separate bed DI resins have certain advantages, however. In particular, if they are kept in different cartridges, they can be recharged.

The recharging process is essentially the reverse of the deionizing process (Figures 6-8). A strong acid (usually hydrochloric acid, HCl) is used to swap H+ for all of the positively charged ions on the cation-binding resin (Na+, K+, Ca++, Mg++, etc.). Likewise, a strong base (usually sodium hydroxide, NaOH) is used to swap OH- for all of the negatively charged ions on the anion binding resin. Both hydrochloric acid and sodium hydroxide are readily available and inexpensive. They are, however, potentially dangerous to work with. The detailed procedures and safety precautions are beyond the scope of this article, but can be found elsewhere online.


Here's another link:

http://www.reefs.org/library/article/g_deutschmann_instruct.html

[JenDub]

Awesome info Randy! I use a lot of water for my business and the thought of a renewable DI solution was tempting. I don't think for the $100 per year that it's worth tangling with highly dangerous chemicals like HCI. One chemical burn and the whole money savings flys out the window.

Thanks!

[Randy Holmes-Farley]

You're welcome.

Happy Reefing. :)

[Hobster]

<a href=showthread.php?s=&postid=7596600#post7596600 target=_blank>Originally posted</a> by JenDub
Awesome info Randy! I use a lot of water for my business and the thought of a renewable DI solution was tempting. I don't think for the $100 per year that it's worth tangling with highly dangerous chemicals like HCI. One chemical burn and the whole money savings flys out the window.

Thanks!

If you don't already do so, you can buy resin in bulk amounts. Might save a few dollars.

http://resindepot.com/

[wlagarde]

Mixed bad resins can be easily recharged. If you place the exhausted mixed bed resin into NaOH first. This will regenerate the anion resin and cause it to float while the cation resin will sink. You can then separate the two resins/remove the cation resin with a baster to another container, rinse, and regenerate with HCl...

Also, you can purchase very cheap pelletized Lye (NaOH) and Muratic acid (concentrated HCL ~23%) at your local hardware store...