Regenerating GFO

tatuvaaj

Pro-Protozoa
Premium Member
In the thread about BioPellets jptenklooster posted this interesting tip:

"However, it will take longer before you have to replace or regenerate your killer (regeneration can be done with 1M NaOH solution, good tip to save some money)."

If you have tried this method, let us know how well it worked :thumbsup:

(I have had 3 kg of GFO in 1M NaOH 4 days now. JP told me to let it sit for one week.)
 
I've not tried sodium hydroxide, but it doesn't surprise me as even salt water can displace the phosphate, IME. It may take a fair amount of water, however.

I'm interested to see how well it works for you. :)
 
Just as a follow up, the iron in GFO (Fe+++) becomes more and more soluble as the pH rises from pH 8 to higher values. 1 M NaOH is about pH 14. At that pH, the amount of iron that dissolves (as Fe(OH)4- ) is just under 0.1 mM (about 5 ppm). So you will be dissolving away some of the surface. That may be beneficial for this process. :)
 
Randy,

Thanks :thumbsup:

Interesting information. I was just wondering if you could tell from the pH how the regeneration is progressing? Once the pH stabilizes there's no more loss of OH- ?

In my case the pH is now ~12.96. I'll check it again tomorrow.
 
My expectation is that the pH won't reliably change unless there is a lot of solid and almost no liquid. A pH drop could also be coming from CO2 entering from the air. :)
 
Yes, it is getting slightly yellow. The pH has dropped to 12.60 (I don't know how accurate that is, the meter was calibrated couple of weeks ago @ 7.0 and 9.0)
 
If you wanted to, you might be able to track the process by measuring phosphate in the fluid, assuming the kit can handle the high pH. If not, you can always acidify it. :)
 
Your wish is my command!

Acidified the sample to pH 7.5, phosphate off the charts :) I didn't try to determine the exact amount (1:9 dilution was still off the charts).
 
Great tip. Just one question for chemistry handicaped ;) what is 1 M? How much quantity of NaOH we need to use? Disolved in fresh water? Or I get that completly wrong?
 
Blue

Look at the periodic chart here
periodic-table.GIF


Now look for Na, O and H Molecular weight

Na = 22.99 grams = 1 mol

O = 16 grams = 1 mol

H = 1.08 grams = 1mol

NaOH has 1 Na, 1 O and 1 H

So, 1 mol of each = 1 mol of NaOH

So, 22.9 + 16 + 1.08 = 38.98 grams = 1 mol of NaOH or ~40 grams = 40,000 ppm

0.1 mol would equal = 4 grams= 4,000 ppm. 1 mmol = 0.04 grams = 40 ppm

If it was 1 mol of CaCO3, has 1 Ca, 1 C and 3 O

~ 40 + ~12 + (3 x 16) = 100 grams = 1000,000 ppm of CaCO3 = 1 mol

mmol times Molecular weight = ppm

and

ppm / Molecular weight = mmol


NSW has 10.27 mmol (0.01027 mol) of Ca++. So, 10.27 x 40 = 411 ppm or 411 ppm x 1.023 d = 420 mg/ l Ca++ .
NSW has 411 ppm / 40 molecular weight of Ca = 10.27 mmol




You do not use things like mg/ l or ppm for solving equations in chem but mol or mmol
 
Who's afraid of the big bad Boomer?

I always thought 1 mole = 6 shrews.


Well anyway, this is very interesting. One of my personal goals is to keep phosphate as low as possible without lots of expenditure (VSV dosing to the rescue) but this is great news.

I'll be following along. Thanks Taatu
 
:rollface::rollface::rollface::rollface:



Red

That depends on the size of the shrew or species of Shrew vs species or size of the Mole :) Now, if we are talking about Pigmy Screws vs Water Screws, then...................................................









































































edit: Deleted, non-reef related subject, Randy Holmes Farley,11/05/09, 10:13 PM
 
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