PO4x4 = iron based polymer?

[Acrotrdco]

Just found this new product called PO4x4, it said it's a "unique chemical engineered polymer based mini pellets" that has all the advantages of GFO but will not leak iron ion into the water column, and will not clump together, etc.

It can also be "generated" by using the "regeneration powder" which is corrosive, sounds pretty much like regenerating GFO with NaOH!

Any idea what this might be, and if their claim of GFO will leak iron ion into water column is true? (i.e. they claimed "Almost every other iron based GFO is releasing iron-ions to the water up to 10 times more than natural seawater levels. This is tested and confirmed at the university of Wageningen, Holland. The tests were done with a inductively coupled plasma mass spectrometer.")

 

[Randy Holmes-Farley]

It is just a polymer coated version of regular GFO pellets. You can regenerate normal GFO, and I'm not convinced the iron release part is true or any different than regular GFO. No polymer coating is selective to passage of phosphate and not iron. They probably took the idea that physical chunks do not break off as readily, and intentionally or unintentionally "misinterpreted" that to read as iron.

I do not doubt that GFO releases soluble iron. I also do not consider that a problem. I add iron to my system.

 

[jtma508]

Being the perennial 'early-adopter' I ordered some of this recently. Still going through Customs I'm told. I'll let you know if it really does out-perform regualr old BRS GFO.

 

[Randy Holmes-Farley]

FWIW, there are other brands that also sell such products and have been around a while. One, which seemingly stole the picture I drew of a phosphate molecule for their label, is shown in this link:

http://www.polyplab.com/3-opti-phos.php

"Opti-Phos is a revolutionary phosphate removal media made from hydrous ferric oxide (HFO) infused into a synthetic bead."

Note the label:

and the picture from one of my phosphate articles:

Phosphate and the Reef Aquarium
http://reefkeeping.com/issues/2006-09/rhf/index.php

 

[Acrotrdco]

Thanks Randy, in that case, I might try getting some after my GFO ran out, to see how they behave in a GFO reactor.

Cheers.

 

[Randy Holmes-Farley]

OK, if you get it, let us know how it works out.

 

[Acrotrdco]

Just got my package today, here's my report:

Packaging - you can see the beads, very uniform size.

Checking my PO4 before testing the PO4x4, using low-range test with my Salifert test kit (using double sample and tester volume), I guess I could say it's between 0.00 and 0.015ppm

Opened package, used about 50ml and added about 150ml RO/DI water, surprised how clear it is, I don't really need to rinse it!

Putting it in a mesh bag and throw it into my reactor, replacing the GFO I was using.

That's it for now, it'll take weeks if not months to test out how well this PO4x4 works, and if it stand up to its claims

 

[Randy Holmes-Farley]

:thumbsup:

Thanks for the update.

 

[2thdeekay]

What size are the beads? Are they uniformly round? Thanks!

 

[HighlandReefer]

Does this article represent the mechanisms that these products are using to remove phosphate?


Hybrid anion exchanger for trace phosphate removal from water and wastewater
http://www.sciencedirect.com/scienc...47d12da267841d85a6a80e3de75c5a47&searchtype=a


Lee M. Blaneya, Suna Cinara and Arup K. SenGupta, a,

aDepartment of Civil and Environmental Engineering, Lehigh University, 13 East Packer Avenue, Bethlehem, PA 18015, USA

Received 30 October 2006; revised 20 December 2006; accepted 3 January 2007. Available online 16 February 2007.

Abstract

Throughout recent decades, the wastewater treatment industry has identified the discharge of nutrients, including phosphates and nitrates, into waterways as a risk to natural environments due to the serious effects of eutrophication. For this reason, new tertiary treatment processes have abounded; these processes generally utilize physico–chemical and biological methods to remove nutrients from secondary wastewaters. The disadvantages of such methods involve larger reactor volumes, operating costs, and waste sludge production; furthermore, complete nutrient removal is unattainable due to thermodynamic and kinetic limitations. The subject study presents the development and performance of a new phosphate-selective sorbent, referred to as hybrid anion exchanger or HAIX. HAIX combines durability and mechanical strength of polymeric anion exchange resins with high sorption affinity of hydrated ferric oxide (HFO) toward phosphate. HAIX is essentially a polymeric anion exchanger within which HFO nanoparticles have been dispersed irreversibly. Laboratory studies show that HAIX selectively removes phosphate from the background of much higher concentrations of competing sulfate, chloride and bicarbonate anions due to the combined presence of Coulombic and Lewis acid–base interactions. Experimental results demonstrate that HAIX's phosphate–sulfate separation factor is over two orders of magnitude greater than that of currently available commercial ion exchange resins. Additionally, optimal HAIX performance occurs at typical secondary wastewater pH conditions i.e., around 7.5. HAIX is amenable to efficient regeneration and reuse with no noticeable loss in capacity.

 

[2thdeekay]

Does this article represent the mechanisms that these products are using to remove phosphate?

I wondered that too. Is it (bead)-CH2-N(CH3)2 / FeO(OH) or something else?

 

[Randy Holmes-Farley]

It may be, but I thought it is simply encapsulated GFO (but don't know that for sure). The anion resins are not useful for phosphate in seawater (I've tried the best known phosphate binding polymer resin).

 

[dzhuo]

Did you really end up not having to wash the media before using it in a reactor?

 

[HighlandReefer]

Thanks for your input Randy.

The articles I have been readings all reference to use the HAIX at around a pH of 7.1-7.5. I'm not sure why or if they are effective at normal reef pH.

 

[Randy Holmes-Farley]

The biggest problem with organic polymers to bind phosphate in seawater is the huge competition for binding sites from chloride and sulfate coupled with a relatively poor affinity for phosphate.

 

[HighlandReefer]

With this information, I am having problems understanding how using a polymer for encapsulating ferric oxide can improve performance for removing phosphate in our reef tank. I can find no studies specific to phosphate. It seems that these polymers are more used for removing arsenic with some mention of strontium.

 

[Acrotrdco]

Did you really end up not having to wash the media before using it in a reactor?

Well I did rinse it with RO/DI water once, that's it. If I were using Rowaphos / GFO I'd have to rinse it at least half a dozen times before I could use them in my sump.

What size are the beads? Are they uniformly round? Thanks!

About half the size of caviar, or if you know what's the size of masago (if you like sushi), that's about the same size.

Read here:
http://en.wikipedia.org/wiki/Tobiko

 

[2thdeekay]

About half the size of caviar, or if you know what's the size of masago (if you like sushi), that's about the same size.
Read here:
http://en.wikipedia.org/wiki/Tobiko

Thanks Acro! Helpful details always nice. Masago/tobiko is a family favorite. :thumbsup:

 

[Acrotrdco]

Randy,

Answering your question regarding whether PO4x4 would not leak iron ion into the water column, one of our local reefer QQ had perform the tests:

He took sample from 3 different sources, from left to right: Rowaphos, common GFO, PO4x4

then soak it in distilled water, wait for 24 hours then measure the iron concentration in the distilled water.

Sample size (the small red cap is about 3.6ml volume, weights 1.68g) -
Rowaphos: 3.19g (0.87 g/ml)

Common GFO - 2.22g (0.62g / ml)

PO4x4 - 2.50g (0.69g / ml)

After mixing with distilled water, you can see the cloudiness of the samples:

24 hours later

As you can see, the Rowaphos sample is still pretty cloudy, and the particle still haven't settle yet, in order to speed this up, the sample is being filtered with a filter paper, but the result isn't that great:

After filtering:

Another 24 hours later
From left to right: new Rowaphas sample rinsed thoroughly with RO/DI water, original Rowaphas sample filtered, GFO sample filtered, PO4x4 sample filtered.

Using Hanna HI 721 colorimeter:

 

[Acrotrdco]

Here're the results:

Original Rowaphos sample filtered:

New Rowaphos sample rinsed with RO/DI thoroughly

As you can see, the difference between the two samples are pretty obvious:

Common GFO sample:

PO4x4 sample:

So I think their claim of not leaking iron ion into water column is actually... true!