Cotton denitrification. so simple, yet so effective

[kwirky]

I read an article (it's not a short read, but it's comprehensive. read here), that explained an experiment which used organic cotton as "both organic carbon source and supporting material for the growth of a denitrifier biofilm."

Exciting stuff guys

They made a simple "continuous reactor system" out of pvc, and then followed it with a trickle filter (they used a sand trickle filter) to remove ammonia and nitrite.

I think the article's a GREAT read, except the production of the bacteria culture involved seeding it with 3 grams of iron... NOT good for our reef aquariums.

So I sent off an e-mail to the researcher involved who specializes in "aerobic biological and chemical treatment of wastewaters", and I'm hoping for a reply. I asked her what the reason for the iron was, and if it was absolutely nessesary. Explained that metals are not desireable in a reef aquarium (although I'm sure she knows this, she teaches doctorate degrees on water purification lol)

It's so simple, though. You pack a tube with cotton, and VERY slowly run water through it. denitrifying bacteria live on the cotton, and use it as a food source in their denitrifying process. They say it's not effective enough for large scale use yet, but I'm sure it's just perfect for our hobby.

In the mean time, anyone have any thoughts on this? It has me pretty excited

Their simple system removed 90% of nitrates when fed a solution containing 85 grams of nitrate per litre. that's insane!

 

[reverendmaynard]

Iron isn't all bad. In fact, some reefers dose iron to aid macro growth.

 

[Bill Wann]

A trickle fileter to remove Nh3 and nitrite ? That would just put the nitrate back into the system again .

 

[boxfishpooalot]

I posted in The chemistry forum for answers This is way more effecient than the market denitrifyers. 10 days and it starts to work.

http://www.reefcentral.com/forums/showthread.php?s=&threadid=861572

 

[Travis L. Stevens]

Technically, I don't see how it would work (without reading the article) unless the cotton was changed often. Cotton is an organic material, too. Wouldn't it eventually break down?

 

[redFishblue]

The cotton was not changed out in the 160 days of testing.
Cotton would break down but not very fast, imo.
Raw cotton has a waxy coating that protects it somewhat from breakdown.

They seeded the cotton with bacteria from a soil sample in the study.
But would you need to do that in a reef tank? Its not like you need to seed a dsb with bacteria.

 

[boxfishpooalot]

Well, Randy from the chemistry forum said that cotton will contain nitrogen and phosphours. And I think that bacteria will break it down to phosphate and nitrate. Also the ammonia effect may be damaging before bacteria get a chance to reduce it to nitrates.