Re gen DI resin

[steve b]

Hi, a couple of questions which can't find on the www. There are a few good sites out there but don't pin down the % solution.

Got a bag full 25l of mixed bed resin that needs regenerating from a friendly window cleaner (could not refuse even though I have some 2l of new resin). Does anyone do this? if so what dilution do you make the Acid and Alkali. I have 30% HCL and 100% costic soda what volume of water to each would you make % solution?

Also does anyone use a Nitrate resin? what flow rate is best for best results. Thanks

[brewmaster15]

Can't help you here Steve, as when I use mine I buy a bulk bag its not that expensive. But I am curious,

bag full 25l of mixed bed resin that needs regenerating from a friendly window cleaner

is this resin dried out or still wet? I seem to remember it can't be dried out as it loses its charge.

al

[steve b]

The cost of 25l mixed bed resin is around £110 here. The resin is still wet in plastic bags so should be okay, just could not see it chucked in the bin.

[brewmaster15]

I dont see any reason why not to try it then.. keep us posted here if you give it a go. Might encourage others to try.

[brewmaster15]

Steve any luck on recharging this resin?

Al

[steve b]

Need Di water for regenerating and only just finished my water filtration system, would you belive the very first time i've made 0 TDS water....
Got all the bits I need just need to do the maths to get the right % of HCL & NAOH. I will post when I do it with photos.

[brewmaster15]

Need Di water for regenerating and only just finished my water filtration system, would you belive the very first time i've made 0 TDS water....
Got all the bits I need just need to do the maths to get the right % of HCL & NAOH. I will post when I do it with photos.

Cool! Looking forward to it.

[Snug]

Here you go.

[brewmaster15]

Here you go.

Thank you!!!!


al

[steve b]

Just got this sorted with help from many internet sites and made a couple of improvements.

Equipment.jpg

Made a separation bottle from a 3L pop bottle, cut the top off and screwed to a board with a 4" soil pipe cut so as to hold the base of it.
Made a better tap connection using a wine maker's tap and hot glued to the cap. Cut the top off a bottle so you can get the hot glue gun inside the cap so you can fill the gap around the tap so no resin sits in the void. The inside of the screw thread has vaseline on it to prevent the glue from sticking to it.

The magnetic stirrer although an option is well worth having as you can do other things as it stirs.
Fine mesh strainers work very well. The wash bottles again are not necessary but a great help when washing out the last bit of resin from the jugs or wash filter.

1/2. Make up Caustic Soda (Sodium Hydroxide) 150gms into 1000ml DI water 15%
3/4. Take 1000ml exhausted DI resin and place into the separation bottle.
5/6. Let the NaOH cool as the specific gravity changes with the heat (for good separation). Pour the 1000ml into the bottle and wait
till the Anion and Cation separate.
7/8. Drain off the Cation resin through the sieve and put the resin into a tub.
9. Drain off the Anion resin through the sieve and put into a tub.
10. I put the Cation resin back in the bottle and add the Sodium Hydroxide to remove any Anion resin left, drain off and place into a
tub.
11. Rinse the Cation resin with 4L DI water to remove as much NaOH before final washing. I leave the Anion resin in the NaOH while
I am regenerating the Cation resin. When the Cation resin is ready I rinse the Anion which should be regenerated by now.
12. Make up the acid solution. 200ml 30% Hydrochloric acid to 800ml DI water 6% HCL.
13. Add the Cation resin into a 1L jug and add the acid to it, it does not use all the liquid so save the excess in a suitable container
for the next batch.
14. I use a magnetic stirrer to stir the solution for 45mins.
15. Place into a tub and rinse with 4L DI water.
16. You should have roughly 50/50 of Anion and Cation resins in two tubs.
17. I use a spare filter pod with an empty resin cartridge to wash the recharged resin.
18/19. Pour the Anion/Cation resin into the cartridge.
20/21. Place into the pod and connect to the DI outlet of your RO system.
22/23. Collect some water from time to time to check the TDS of the water or have a TDS probe on the out line. When the required
TDS is reached stop washing.
24. Empty the resin out and store in a zip lock bag.

Layout flat numbered 30mb size.jpg

At the moment I am keeping the resins separate. I may use them as separates or mix them, if they are used separate then you would miss out the steps to separate the resins. think I might try this and add a 3rd pod to the DI with a mixed bed as in the information from BRS site.
Throw away the used NaOH as I have tried to re use it to seperate the resins but did not work a second time.
Some sites say to regenerate the Anion resin with a 4% solution of NaOH for 45min others say it's regenerate in the separation bottle.
Put all waste liquid in the same waste bucket to neutralize each other.
All I can say is check out the other sites and do your own thing as I have done.

Cost per 1L of recharged resin.

5000L 30% acid @ £7.00 /200 = use 25 times £0.28p

1000gms NaOH @ £4.50 /150 = use 6.6 times £0.68p

£0.96p per 1kg 8L DI water and wash DI 40L and your time, about 2 hours.




How to Recharge DI Resin by David Sanders - Reefkeeping.com
Is this a legit way to regenerate DI | REEF2REEF Saltwater and Reef Aquarium Forum
HOW TO REGENERATE DI RESIN - Fast and easy method - YouTube
https://www.bulkreefsupply.com/conte...sin-maybe-both

[brewmaster15]

Steve thats a thorough write up ..thank you! I am going to stick this thread to the top of the section for easier reference. thanks again!

Al

[steve b]

Thanks Al, if you make up the NaOH solution before you need it (stock solution and store in a suitable container) so it's cool and ready to use you could knock off about 30 mins to the working time.
Also keeping a note of the amount of water going through the bought new DI resin and when that needs replacing will have a figure to go by when using the regenerated resin as see if there is a difference in volume.