Regenerating GFO

[teebs]

Originally Posted by Matt_Wandell

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.

[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]

Originally Posted by 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 ...

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]

Originally Posted by tatuvaaj

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

(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%201969-70.pdf

Thanks,
Vic

[Matt_Wandell]

Originally Posted by jptenklooster

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!

[SimonSKL]

Matt,
+1!

[mike810]

after regenerating my gfo. do i have to dry it or can i just store it wet and use it wet?

[SimonSKL]

I store mine wet.

[mike810]

thanks

[rob.mwpropane]

So after some math (rounded on some), and some headache, I think I have a game plan. I just want to run it by everone first. (Great thread by the way, thankyou to all those involved that could make this possible!!) If I only have a 65 gallon tank, and I'm using 1 tablespoon HCGFO per 8 gallons, 8 tablespoons in all, then I believe that equals 118.4ml of GFO.(I'll say 1/4 of 500ml per instructions). If this is correct then:

Step 1: About 1/2 gallon (2L) ro/di mixed with 1.6ml muriatic acid for 4-6 hours

Step 2: About 1/2 gallon (2L) ro/di mixed with 80 grams sodium hydroxide fo 96 hours (4 days)

Step 3: About 1.6 gallons (6.25L) ro/di water into drain... more like 2 gallons to be on the safe side

Sorry for the lengthy stuff, but I am neither a chemist, or a math teacher, I'm just a guy that doesn't want to melt his gfo reactor, or kill his fish/coral. Now if you want to talk propane tanks, that's a different story...

[mike810]

I don't think you need the muriatic acid step. Just take a pinch of your GFO to be regenerated and toss it in a cup of vinegar. If it fizzles due to calcium build up then you need to do a vinegar bath first before you regenerate.

I skip the vinegar bath and regenerate right away. (no calcium build up on GFO) I believe this is how it work. HTH

[rob.mwpropane]

Yeah, I don't think that I would need the 1st step either, but I have plenty of muriatic acid laying around to recharge di so I figured what the heck. I think I have all my math right, the only thing I'm missing is a p04 test. I actually just plan to rinse a little more than the instructions call for. That's not ideal, but....

Has anyone had any problems regenerating gfo to date?

[mike810]

I rinse my GFO after the regen with about 2-3 gallons of RO. drain and store wet, when I do a water change. I change out the GFO then run an additional 5 gallons of tank water through the reactor into a bucket to further rinse it.

[gary faulkner]

Do you dump the Sodium Hydroxide solution after just one regeneration. And do you neutrilize it first?
Thanks

[rob.mwpropane]

I don't know if the sodium hydroxide can be reused, I would assume not. It's going to be loaded with p04, and would probably make it twice as hard to recharge the gfo. And I can't imagine neutralizing it. I mean if you wanted to, you could use muriatic acid, or vinegar... but sodium hydroxide is a drain opener. Just use it on your least productive drain and kill two birds with one stone.

Disclaimer: Now with all that said, I am not an expert, and my best science is based off of what is written here, and good old fasioned "edumacated" guesses. So I hope someone else will chime in and say I'm right... or wrong....