tecapparatus
New member
For small scale regeneration, ~ 5c (one - 1.75 lb BRS HC GFO) what is the best setup besides 2nd BRS reactor?
Regenerating GFO
- Thread starter tatuvaaj
- Start date
Tomoko Schum
New member
I broke two powerhead impellers by recharging GFO in a reactor. I have seen a few postings here and there about the same problem.
My GFO is now sitting in a bucket of lye after circulating about 72 hours. I don't have any more spare powerhead. Should I just take out the recharged GFO out of the reactor and rinse it in a bucket of RODI water a few times?
In the future I would like to try recharging GFO in a container instead of using a reactor and a powerhead. What container do you use and how do you agitate GFO to make sure GFO is recharged evenly?
My GFO is now sitting in a bucket of lye after circulating about 72 hours. I don't have any more spare powerhead. Should I just take out the recharged GFO out of the reactor and rinse it in a bucket of RODI water a few times?
In the future I would like to try recharging GFO in a container instead of using a reactor and a powerhead. What container do you use and how do you agitate GFO to make sure GFO is recharged evenly?
MGM_
New member
I had problems with the MJ's but switched to a mag5 and it is holding up well. The MJ impellars do not like the Lye or to fragile for the inevitable GFO dust recirculating. You can rinse in RODI water. Others have commented on this method as far as quantity of rinse and I do not recall. For larger tank its not a concern as you will only raise your ALK.
As for a container I think a flat rectangular container would give largest surface exposure. The reactor with pump seems to do better job than a "soak" type regen for me.
As for a container I think a flat rectangular container would give largest surface exposure. The reactor with pump seems to do better job than a "soak" type regen for me.
MGM_
New member
I had problems with the MJ's but switched to a mag5 and it is holding up well. The MJ impellars do not like the Lye or to fragile for the inevitable GFO dust recirculating. You can rinse in RODI water. Others have commented on this method as far as quantity of rinse and I do not recall. For larger tank its not a concern as you will only raise your ALK.
As for a container I think a flat rectangular container would give largest surface exposure. The reactor with pump seems to do better job than a "soak" type regen for me.
As for a container I think a flat rectangular container would give largest surface exposure. The reactor with pump seems to do better job than a "soak" type regen for me.
tecapparatus
New member
Does this dust end up looking similar to red cyano slime? but kinda dusty?
The more regen cycles you do the more dust you generate, too. I regen in reactors and my dust accumulates at the bottom of my NaOH reservoir, I have a few cartridges of HC that are on about cycle 10 and the grain size is noticeably smaller than fresh HC, but it still works just fine!
I use a Pan World external pump. No problems after about 25 cycles or 100 days of operation.
I use a Pan World external pump. No problems after about 25 cycles or 100 days of operation.
KCombs
They Call me "RifRaf"
I had been saving my spent GFO for a few months while building up the nerve to try this....
Anyway, I followed the procedure faily well except I went 12hr over (60hrs I think)
but during rinsing I keep geting dust "fines"; the water in the bucket remains rusty ....seems its never rinses "clear"....
is this normal or did I "regen" it for too long and the media is ruined ?
(I went about 60hrs I think)
ampemployee1
Member
KCombs, I'm not sure if you used HC or granulated GFO. In my case, I used the granulated. I rinsed with 10 gallons of fresh RO/DI water, then took the remaining GFO and put it into a filter sock. I dipped the filter sock into another 2-3 gallons of RO/DI in a container (like a tea bag), 20-30x, dumped the water and did it again. The water never comes out 100% clear, but I feel it did a good enough job to rinse out the fines so it doesn't turn your entire system into a murky rust color. I run my GFO passively in a filter sock in my sump. IMO, you could rinse with 100 gallons of RO/DI (not practical), and the color will still come out rusty as the rinsing causes some friction amongst the granules, and degrades the media too much. You'll end up with paste. I'm going to purchase some HC, from what I've read on this thread, it holds up better to regeneration than the standard granulated type.
lostmyz
New member
I like this idea of regenerating my GFO cause the stuff is distgustingly $$$ and I'd rather reuse my resources than toss them in the trash. After reading this article and how people have been doing it. I am slightly confused not by the chemistry but by the actual process... I know you need to use 1M soln of NaOH and have the GFO soak in this solution for 4days... afterwards which you can rinse it off in RO/DI. But are you using a 3:1 ratio of (NaOH soln: used GFO???) If someone can tell me the exact step by step process that be awesome!!!
Thanks
Thanks
Brummie
Member
Not sure if I got the technical terms or the maths right, but this is how I've done it;http://algaescrubber.net/forums/showthread.php?2518-DI-Regeneration&p=29411&viewfull=1#post29411
On the third regeneration now
Brummie
Member
Hmmm, can't edit post to get the link to work;
GFO regeneration test underway.
1 litre of 1M (ish) sodium hydroxide solution (150mls 16% NaOH in 1 litre RODI), exhausted GFO. Leave the regenerant to replace phosphate ions with hyroxyl ions on the binding sites of the GFO is the first stage. This will take 3 days with an occassional gentle mix.
After 3 days I will dilute the regenerant (1:100) so that I can test for phosphate presence, therefore indicating its effectiveness. Then I need to rinse the GFO. Will post progress at that stage.
GFO regeneration test underway.
1 litre of 1M (ish) sodium hydroxide solution (150mls 16% NaOH in 1 litre RODI), exhausted GFO. Leave the regenerant to replace phosphate ions with hyroxyl ions on the binding sites of the GFO is the first stage. This will take 3 days with an occassional gentle mix.
After 3 days I will dilute the regenerant (1:100) so that I can test for phosphate presence, therefore indicating its effectiveness. Then I need to rinse the GFO. Will post progress at that stage.
Brummie
Member
Tested the regenerant today (used 4.5 litres in total), took samples from each 1.5 litre batch and averaged the reading after neutralisation with a few mls of HCL.
Got a reading of 1.1ppm (diluted by 200), so 220ppm in 4.5ltrs is 2.2ppm in a 450 litre tank from 250grms of GFO. So now this regenerated GFO is capable of removing another 2.2ppm (450 ltr tank), over time. The regenerated GFO shows no to little degradation.
All that's needed now is a bloody good rinse in lots of RODI, as described in the above link, and it's done, almost free of cost. Gonna rinse slowly, over next few days with about 20ltrs RODI to be sure, then test it.
Got a reading of 1.1ppm (diluted by 200), so 220ppm in 4.5ltrs is 2.2ppm in a 450 litre tank from 250grms of GFO. So now this regenerated GFO is capable of removing another 2.2ppm (450 ltr tank), over time. The regenerated GFO shows no to little degradation.
All that's needed now is a bloody good rinse in lots of RODI, as described in the above link, and it's done, almost free of cost. Gonna rinse slowly, over next few days with about 20ltrs RODI to be sure, then test it.
ReefKeeper64
Wanna be a reefkeeper
tagging along.
Psionicdragon
New member
what is the effect of lye if it gets in your tank?
blanden.adam
Team RC
Lye will raise the pH and increase the alkalinity. If it is a low grade chemical, then imputities could also get in. To what degree depends on how much gets in and how pure it is. But rest assured, it's not that big of a concern. A few volumes with good mixing and adequate equilibration time should be sufficient (the key is good mixing and adequate equilibration time, if you just run water through the resin as is often done it will take much more water). If you are worried you can always check the pH of the effluent/supernatant. If its below say 10ish you're probably fine.
dkeller_nc
New member
I've found that rinsing GFO in RODI to remove the regeneration hydroxide can take quite a few rinses - I calculated 9 volumes of RODI per volume of GFO, with 10 minute equilibrations for each rinse (to allow hydroxide in the pores of the solid to diffuse into the bulk liquid). The end-point I was using was phenolphthalein, which is colorless below pH 8.2.
A considerably more efficient rinse was 0.01N HCl (obviously, since the HCl will neutralize the NaOH to salt and water), which took 4 volumes/volume of GFO to reach the phenolphthalein end point.
For those looking to do this that read the Advanced Aquarist article: please do not set up a reactor and a pump to circulate 1M NaOH through GFO. This is really dangerous, as you're pressurizing a caustic chemical that will burn your skin and eyes faster than you can rinse it off. All it takes is a hose barb connection to come loose to get sprayed.
And - circulating NaOH through GFO via a pump and a reactor isn't necessary. Simply soaking GFO in 3 successive 2X volumes of NaOH with 24 hours between changes is all that's required.
A considerably more efficient rinse was 0.01N HCl (obviously, since the HCl will neutralize the NaOH to salt and water), which took 4 volumes/volume of GFO to reach the phenolphthalein end point.
For those looking to do this that read the Advanced Aquarist article: please do not set up a reactor and a pump to circulate 1M NaOH through GFO. This is really dangerous, as you're pressurizing a caustic chemical that will burn your skin and eyes faster than you can rinse it off. All it takes is a hose barb connection to come loose to get sprayed.
And - circulating NaOH through GFO via a pump and a reactor isn't necessary. Simply soaking GFO in 3 successive 2X volumes of NaOH with 24 hours between changes is all that's required.
