Regenerating GFO

[teebs]

I just diluted 25ml of the solution in 1L of DI water and used vinegar to adjust the PH to 8.0.

Tested the solution using my salifert PO4 test kit and reading came to between 0 - 0.03ppm po4.

Used my Hanna HI736 ULR meter to counter check the reading and got 84ppb = 0.2575ppm PO4.

I guess the Hanna is definately more accurate so can I say that the solution has approx 10ppm of PO4 in it?

 

[falconut]

teebs - That's good to know. I must assume that I have a regenerated batch sitting in RO water. After soaking in the solution, did you have the same lighter substance on top of the GFO?

 

[teebs]

teebs - That's good to know. I must assume that I have a regenerated batch sitting in RO water. After soaking in the solution, did you have the same lighter substance on top of the GFO?

Yes, I have a thin layer of brown dust on top of the GFO. Hope that my attempt at regenerating GFO is successful...

 

[Matt_Wandell]

I just diluted 25ml of the solution in 1L of DI water and used vinegar to adjust the PH to 8.0.

Tested the solution using my salifert PO4 test kit and reading came to between 0 - 0.03ppm po4.

Used my Hanna HI736 ULR meter to counter check the reading and got 84ppb = 0.2575ppm PO4.

I guess the Hanna is definately more accurate so can I say that the solution has approx 10ppm of PO4 in it?

That's odd that you're getting a discrepancy in the tests. Assuming the reading from your Hanna meter is accurate that would be around 10ppm.

How much GFO do you have? Is it just sitting there, or have you stirred it?

 

[noobtothereef]

where can lye be purchased?

 

[teebs]

That's odd that you're getting a discrepancy in the tests. Assuming the reading from your Hanna meter is accurate that would be around 10ppm.

How much GFO do you have? Is it just sitting there, or have you stirred it?

I am stirring it twice a day, in the morning and evening. Amount of GFO is approx 1L. Sitting in approx 5L of 0.5M NaOH solution. I'm not sure if this 10ppm PO4 is considered a lot or is it very little considering the amount of GFO and solution that I have?

I'm quite sure my Hanna meter is accurate as the salifert test kit always indicates 0 - 0.05ppm PO4 regardless on what is tested on my Hanna meter.:spin3:

 

[thi7b]

Have anyone use Drano to regenerate?

 

[falconut]

I spoke to the Drano company and their crystals aren't pure, so I wouldn't use it. I got the Rooto (1030) it says 100% lye and I was able to get it at my local Ace Hardware for $3.50 for a lb.

 

[thi7b]

Thanks falconut

 

[Matt_Wandell]

Here's the article Laurie and I put together. Many thanks to everyone in this thread for inspiration!

http://www.advancedaquarist.com/2010/10/chemistry

 

[rcorbitt]

Nice article, but I think you should have given some credit to the folks on this thread. Since there's no mention, it almost appears as though you did all the testing yourself ...

 

[Matt_Wandell]

Nice article, but I think you should have given some credit to the folks on this thread. Since there's no mention, it almost appears as though you did all the testing yourself ...

We (Laurie and I) did do all the testing ourselves. We spent about 20 hours in a lab testing several concentrations, durations, and iterations of GFO regeneration to determine a sufficient concentration of sodium hydroxide and duration to use. We did this because our jobs and budgets depend on it--we're setting up a GFO reactor for a 200,000g tank and regenerating it as efficiently as possible saves time and money. I didn't list all that info because, frankly, it's pretty boring and of little interest to the average hobbyist that just wants to know how to do it.

 

[SimonSKL]

Matt, very nice article that you and Laura did. I am sure many hobbyists will find it extremely useful, not only saving money but also protect the environment as well. Well done and thank you!

 

[jptenklooster]

well, it would have been proper to name those people that came up with the idea, and yes, that would be me

 

[jptenklooster]

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.)

 

[tmz]

Hi, jptenklooster. Sincere thanks for introducing this technique. Unfortunately this is not as good as an article where you could receive proper recognition but thankyou just the same.

 

[jptenklooster]

very much appreciated

 

[vic8361]

I bought this product from home depot.
Here's the specs can I use it?
Also how much do I need to use to regenerate a gallon of gfo?

http://www.scotchcorp.com/downloads/MSDS 1969-70.pdf

Thanks,
Vic

 

[Matt_Wandell]

well, it would have been proper to name those people that came up with the idea, and yes, that would be me

The claim that you came up with the idea is demonstrably false. It has been published in countless papers since at least the 1990's.

For example, one of the earlier references for the procedure of regenerating ferric oxide media using sodium hydroxide (in 1996):

"Removal of Arsenic from Ground Water by Iron Oxide-Coated Sand", A. Joshi and M. Chaudhari.
Journal of Environmental Engineering August 1996.

"Before commencing the next cycle of runs, the medium was regenerated in situ by passing 10L of a 0.2N sodium hydroxide solution, followed by washing with 10L of water."
http://www.bvsde.ops-oms.org/bvsacd/arsenico/arum.pdf

Here is another, from 2002:

"Arsenic treatment technologies for soil, waste, and water"*By United States. Environmental Protection Agency. Office of Solid Waste and Emergency Response
Sept 2002

From Section 11-1

"The regeneration fluid most commonly used for AA treatment systems [using GFH/GFO] is a solution of sodium hydroxide."

To be very clear, there is no claim in our article that we "came up with" nor invented any process.

The goal of the article was to present very simple to follow instructions for new users to regenerate GFH/GFO. We based these instructions on data we generated using GFH/GFO from reef aquariums so that others would not have to go through the very long and arduous task of generating the data themselves. We did not feel it relevant to include information pertaining to the timeline or genesis of the process in industrial wastewater applications back in the 1990's (or earlier).

Likewise, if we wrote an article about kalkwasser, LEDs, or a protein skimmer, and presented measurements of, for example, conductivity of the kalkwasser after X hours, or PAR data from brand X LED fixture, or TOC removal of brand X protein skimmer after Y hours, we would not feel the need to reference the first person that mentioned these items on a reef hobbyist internet bulletin board, nor discuss the genesis of these items in industrial applications.

Hopefully this clears up any questions about references in the article. If you have any more concerns I can be reached privately at mwandell@calacademy.org

Thanks,
Matt

 

[SimonSKL]

Matt,
+1!