Sciencemadness Discussion Board - Generating HNO3 from NH4 in lab scale?

Generating HNO3 from NH4 in lab scale?

chucknorris - 14-12-2012 at 00:47

Quote:

In this process, anhydrous ammonia is oxidized to nitric oxide, in the presence of platinum or rhodium gauge catalyst at a high temperature of about 500 K and a pressure of 9 bar. 4 NH3 (g) + 5 O2 (g) → 4 NO (g) + 6 H2O (g) (ΔH = −905.2 kJ) Nitric oxide is then reacted with oxygen in air to form nitrogen dioxide. 2 NO (g) + O2 (g) → 2 NO2 (g) (ΔH = −114 kJ/mol) This is subsequently absorbed in water to form nitric acid and nitric oxide. 3 NO2 (g) + H2O (l) → 2 HNO3 (aq) + NO (g) (ΔH = −117 kJ/mol) The nitric oxide is cycled back for reoxidation. Alternatively, if the last step is carried out in air: 4 NO2 (g) + O2 (g) + 2 H2O (l) → 4 HNO3 (aq)

Has anyone attempted to generate HNO3 with this method? Ammonia gas is easily available from any ammonia based fertilizer (ammonium sulfate, phosphate, etc.).

Vargouille - 14-12-2012 at 01:59

I believe Plante(1999) has done something similar, but at atmospheric pressure and with aqueous ammonia. Here is the link to his apparatus (using platinized asbestos).

plante1999 - 14-12-2012 at 04:43

I did, I'm still working on the process tough. The reaction tube was changed to a 5 mm quartz tube because the air flow was too slow for the big tube and the glass melted at the temperature involved. I reacted the nitric acid with sodium carbonate and boiled sown to get sodium nitrate. When I burned some sodium nitrate with sugar, I was amazed by the potential of the synthesis. So I made more and more sodium nitrate with it, and now I have 50-60g of NaNO3.

I found that air pressure doesn't change much the yield, but they change the quantity of the nitrous gas absorbed. It is good to know that Using only one fish air pump is really slow for this reaction, using oxygen rich air or more air pump would accelerate the production. It also consume quite a lot of fuel to maintain good catalyst temperature. The catalyst is very good however and have a very long service life at atmospheric pressure.

Now I will try biochemical way of making nitrate out of ammonia, so I will be able to make a comparison. With more pump the Ostwald process would be really good, but sadly each pump cost 15$ CAD.

plante1999 - 15-12-2012 at 17:26

Only one day till I buy the material for biochemical production. Does anyone have something to say?

I have read that the nitrobacter need a solid-non soluble in acidic condition medium for living. A sort of support "house". Any idea for a support? I thought to use calcium carbonate as a buffer and as a support, but I don't think the bacteria will like to live on an unstable slowly dissolving media. Its much like if they live on an ending word...

shannon dove - 16-12-2012 at 00:01

I did the ammonia into nitric /nitrous acid about 8 years ago. I got to say I felt on top of the world that day because it was the only chemical project I had done that I actually had success with.
I also used an aquarium air pump. I bubbled air through ammonia /water cleaning solution bought at grocery store, then run it through red hot copper tubing. No catalyst except the copper oxide in the copper tubing. After a lot of complicated math, I figured it was 6% acid that dripped out of the cold end of the tube. I think it was also blue, I guess from copper contamination. So the acid was very dilute.
I even tried it at lower temperature, maybe 300 Celsius and it looked and smelled like unchanged ammonia /water that dripped out of tube, but when I used a nitrate aquarium test, it had a ton of nitrate ions in it, and just to make sure it was not there already, I tested it with no heat on copper tube, and it was absolutely no nitrate ions in it.

Nicodem - 16-12-2012 at 02:33

Quote: Originally posted by plante1999

I have read that the nitrobacter need a solid-non soluble in acidic condition medium for living. A sort of support "house". Any idea for a support?

The obvious choice is to use the nitrobacter ceramic support as sold in any pet store for use in aquarium filters. The material is especially optimized for nitrifying bacteria to colonize it and thrive on it (and it is cheap as well). The shape is also suitable for good flowability of the liquid, so that anaerobic spots can be avoided. The newly bought filter chips are not yet inoculated (generally they require a nitrobacter colony start up by letting the aquarium filter run for one month in a conditioning aquarium: search for "aquarium cycling"). You will need a strong flow and a lot of aeration if you want to grow a strong enough colony for preparative use, so you will also need an aquarium air pump and/or a strong aquarium filter pump, depending on your fermentation reactor design. The simplest setup would probably be a reactor fully filled with filter chips with an aquarium air diffuser at the bottom to function both, as an aerator and mixer.

plante1999 - 16-12-2012 at 07:44

I looked for ceramic suport but I didn't found any, does charcoal/actived charcoal could be used instead?

I have saw the aquafine cycle bottle wichi is supposed to be a biological ammonia and nitrite remover, but the solution is colorless, is that normal for the bacteria "solution"?

http://www.walmart.ca/en/ip/nutrafin-cycle-biological-aquari...

Mailinmypocket - 16-12-2012 at 08:02

This is the kind of bacterial support media Nicodem mentioned, you can find it at aquarium stores or some well stocked pet shops. It had a consistency similar to perlite ... Maybe you could use perlite? The bacterial supplements are usually relatively clear, but usually have small flocculent particles in them. In my fish-keeping experience every supplement I have bought has a very slightly cloudy appearance.

[Edited on 16-12-2012 by Mailinmypocket]

S.C. Wack - 16-12-2012 at 08:33

Assume that nitrification (like everything else, newer members), even on a large scale, has come up here before. (It happens to be convenient that you're from Quebec.)

plante1999 - 16-12-2012 at 08:34

Hmm, could you test if the medium is resistant to acid for me? I found similar stuff that they were calling porous rock for absorbing ammonia but they were 6$ and I didn't knew there composition. Thanks for the bacteria tip!

I wonder if they would live on activated charcoal.

Mailinmypocket - 16-12-2012 at 08:42

Quote: Originally posted by plante1999

Hmm, could you test if the medium is resistant to acid for me? I found similar stuff that they were calling porous rock for absorbing ammonia but they were 6$ and I didn't knew there composition. Thanks for the bacteria tip!

I wonder if they would live on activated charcoal.

The porous rock labelled as ammonia remover can vary... There is a product called Am-rid which remove ammonia via absorption as opposed to harboring bacterial colonies that break it down..

There is also this medium which seems better suited for your needs... You can order it fairly cheap from mops.ca

I suppose I could test acid resistance but how resistant do you need it to be? Let me know the conc. and I will test it out for you

[Edited on 16-12-2012 by Mailinmypocket]

plante1999 - 16-12-2012 at 08:50

Quote: Originally posted by S.C. Wack

Assume that nitrification (like everything else, newer members), even on a large scale, has come up here before. (It happens to be convenient that you're from Quebec.)

I'm not exactly sure I understood this one!

Mailinmypocket, testing with dilute nitric acid, like the bacteria will make.

Since the nitric acid is directly produced on the medium.

Mailinmypocket - 16-12-2012 at 09:31

Ok- added a piece to some 10% HNO3. No obvious reaction but ill let it sit all day and report back.

plante1999 - 16-12-2012 at 09:41

Good, thanks!

If it is good I will try to find some, however activated carbon would be easier for me. Will one fish air pump would be sufficient for mixing and for a good colony of bacteria? I will also add calcium carbonate piece to the medium to neutralise the acid produced. The water should have this fallowing composition:

500 ml H2O
0.5 g FeSO4 (hydrated)
3 g MgSO4 (hydrated)
4 g Na3PO4 (anhydrous)
0.2g KCl
10 ml 30% ammonia

Does that seams right to everybody?

S.C. Wack - 16-12-2012 at 13:16

Or inconvenient. Never mind.

plante1999 - 16-12-2012 at 14:50

The bacteria doesn't seams to live in the media I told...

I saw that they live on pH 8 so I made a new test with very low ammonia 1 drop of 30% in 100ml sol.

few crystals of Na3PO4 and MgSO4
2 g of NaHCO3 buffer to get the desired pH

So any thought?

phlogiston - 16-12-2012 at 15:12

I also experimented with the Ostwald process a little bit, but never tried any production runs.

I first tried a little loose plug of fine copper wire (from electricity wire) in a 5mm glass tube (pasteurs pipette), and pulled air + ammonia through with suction. It seemed to work in the sense that the (briefly preheated) copper immediately started to glow brightly and if the NH3 content of the flow was too high, it quickly melted both the copper wire and the glass tube.
However, I didn't see any brown clouds of NO2, and I wander if I actually got N2 rather than NOx.

NH3 + NO + 1/4 O2 ---> N2 + 3/2 H2O.

When I absorbed the gas in water, it became alkaline rather than acidic.
Perhaps I had an excess of NH3 and got NH4NO3 mostly.

I also tried a little platinum-coated titanium tube (3 mm inner diameter), which yielded essentially the same result and didn't melt, but it is obviously much more expensive.

plante1999 - 16-12-2012 at 15:27

Well, copper catalyse the oxidation of ammonia to nitrogen, you would be better to use platinized asbestos like me, platinum ctalyse ammonia oxidation to NO which oxidize in air to get NO2. I got good results, and cloud of NO2.

For the biochemical preparation:

I made a nitrite test solution by hydrolysing 0.1g of paracetamol which 3 ml of Conc. HCl in 20 ml of water. Then I tryed my test solution on a premade nitrite solution. I put one crystal of sodium nitrite in 100ml of water. I took 2 small sample of the solution, in one I added ammonia. Then I added one drop of the test solution and both become yellow. I also tested the test solution in distilled water but the solution didn't changed color, prouving that my test solution was working. Then I tryed the test solution on a sample of my biochemical medium after 2 hour of run. No nitrite was detected.

So I checked the pH and it was 10. Since bacteria are supposed to grow in pH of 7-8 I made a New medium.

Does someone have a new medium composition for the colony? At the moment the bacteria lives in activated carbon.

[Edited on 16-12-2012 by plante1999]

Mailinmypocket - 16-12-2012 at 15:35

Just an update:

The support media I have tested today with ~10% HNO3 shows no signs of degradation. Air escapes at first and when swirled for the first couple times there was a slight sediment that stirred up. I boiled it for one minute and let it sit another couple hours. No visible damage... I didn't bother drying the sample, exposing to acid, rinsing and re-drying since this was just a crude test. But I think you would be good to go with something like this product.

This might be a thread better suited to biochemistry by the way!

[Edited on 17-12-2012 by Mailinmypocket]

plante1999 - 16-12-2012 at 15:48

I agree, thanks for the try but Now I'm in the problem of making a LIVING colonies, it seams I do something wrong... As it doesn't seams to have anything living.

First I guess a 500 ml to 1L reaction vessel would be better. Than I would need to know a "recipe" for a good medium. I have hard time trying to make a living colonie.

Mailinmypocket - 16-12-2012 at 16:01

Quote: Originally posted by plante1999

I agree, thanks for the try but Now I'm in the problem of making a LIVING colonies, it seams I do something wrong... As it doesn't seams to have anything living.

First I guess a 500 ml to 1L reaction vessel would be better. Than I would need to know a "recipe" for a good medium. I have hard time trying to make a living colonie.

What you might want to try is keeping one fish (gold fish work fine) in a small tank with a simple filter. Let it go for a while until you can collect scum from inside the filters. Use this material to colonize your media. Having a live ecosystem to collect bacteria/cultures from is far better than starting straight off with those supplements. IMO.

plante1999 - 16-12-2012 at 16:23

Would activated carbon work as the filter?

Anyway I think ammonium salt would be better then ammonia, since I'm always bufering the media after each ammonia drop. Any thought for the ammonium salt?

I'm starting to think that calcium carbonate have serious advantage. A medium with calcium carbonate on the bottom and adding ammonium salt to it, maybe even urea would be good.

The ammonium salt/urea doesn't interfere with the pH but when pH get low the calcium carbonate react with HNO3 to get about a pH 7 to 8. Then there is the medium that migth help, activated charcoal migth not be the best house for the colonies.

I would also like to know how I could test for living bacteria.

MagicJigPipe - 16-12-2012 at 17:00

"I would also like to know how I could test for living bacteria. "

Errrr... A petri dish and a microscope...

phlogiston - 17-12-2012 at 01:37

Normally, in microbiological work, you sterilize your medium first and then inoculate with the desired species. If you don't you will get all sorts of 'wild' bacteria and fungi that will compete with your nitrificating bacteria and may take over. And it is actually quite tough to keep a culture from being infected with other species for extended periods of time, unless the conditions are so unusual that they greatly favour the desired bacterium over other species.

Edit: The simplest way to test for viable bacteria is to plate them onto a slab of solidified medium (using agar-agar) in a petri dish and allow them to grow. You should then be able to count the colonies (each of which sprouted from a single viable cell, if you diluted the sample sufficiently).

[Edited on 17-12-2012 by phlogiston]

plante1999 - 17-12-2012 at 04:54

Thanks for the tip!, As you can see I'm not a microbiologist.

So. my 500 ml solution is clear but have some carbon dust in it. But no cloudiness like previous try. I guess the bacteria are in the activated charcoal. I added 1 ml 20% ammonium chloride solution as the ammonium source, and the pH is still 8, which is supposed to be ideal for them. I have about 2 g of sodium bicarbonate buffer. When the ammonium will be used up, HCl will react with the bicarbonate, making chloride and the nitric acid will too. When the bicarbonate will be used up increase in acidity should be observed and prove biological activity.

Soon I will try to use urea for the ammonium salt source and add calcium carbonate buffer to the bottom. I may change the substrate too.

Phlogiston if other organism try to live in there it should still be good since these bacteria usually live in these condition ( fish tank).

[Edited on 17-12-2012 by plante1999]

phlogiston - 17-12-2012 at 06:23

There may be other bacteria that do well under the same conditions that do not produce nitrates, and they may take over your fishtank.

Where did you get the composition of the medium? You don't seem to add any source of carbon. Most bacterial media that I have ever used contain glycerol, glucose, ethanol or some other 'fuel' that bacteria like.

plante1999 - 17-12-2012 at 09:14

Nitrobacter do not use carbon source, they will only grow with CO2. In the presence of organic compound they will not grow. And by the way I don't use a fissh tank but I mean these bacteria could be found in it.

Edit:
The pH dropped to 7, so I suppose there some activity in the medium, more update soon.

I bought calcium carbonate and urea, I will do an urea addition.

Edit 2:
I added 1 ml of saturated urea solution and the pH turned back to 8. I may add this peppermint calcium carbonate pills soon.

[Edited on 17-12-2012 by plante1999]

[Edited on 17-12-2012 by plante1999]

plante1999 - 17-12-2012 at 12:20

Few tenth of minutes after the urea addition the pH was 7.5. It was run for another hour and then the pH was found to be 6-7 so I tested my calcium carbonate pills, I dropped one in distilled water to see if there was an evident reaction. Nothing happened. Then I added 9 pills of 0.5g calcium carbonate each, or 4.5g. Imediatly bubble formed on them, they dissolved somewhat and 2 minute latter the pH was back to 8-8.5.

[Edited on 17-12-2012 by plante1999]

Mailinmypocket - 17-12-2012 at 14:59

Quote: Originally posted by plante1999

I may add this peppermint calcium carbonate pills soon.

Peppermint? Are you using antacid tablets?

Why not use chalk?

plante1999 - 17-12-2012 at 15:13

Yes I use antacid tablet because I don't have any chalk and I didn't wanted to use seashells.

Edit:

I added one ml of saturated urea sol., the pH is still 8 and the calcium carbonate is partially dissolved. I should be able to test for calcium salt by taking some of the solution and adding sodium bicarbonate solution to it. Cloudiness would tell that some soluble calcium salt are present.

Summary of the first 24 hour of run of the bioreactor:

hour 1: Ammonium chloride, sodium bicarbonate, activated charcoal and the bacteria source were added. pH 8

Hour 11: The pH was now 7. First urea addition, 1 ml of 26%. pH 8.

Hour 16: pH 6.5-7. Addition of 1ml of 26% urea and calcium carbonate. Effervescence with the calcium carbonate. pH increase to 8.

Hour 20: pH still 8. Addition of 1 ml urea 26% sol. Calcium carbonate mostly in tiny pieces format.

Hour 22: pH still 8. Addition of 1 ml 26% urea sol.

Interpretation:

Hour 11: The bacteria colonies used most of the ammonium to make nitric acid and most of the bicarbonate was neutralized. When the urea was added, urea nitrate was formed neutralising the acid and increasing pH.

Hour 16: Urea was metabolised by the colonies to make nitric acid lowering the pH. Calcium carbonate reacted with the nitric acid to yield CO2 and Calcium nitrate, increasing the pH. The calcium carbonate buff the pH to 8.

Remark:

I read that the calcium carbonate is not only used to buff the pH, but also as the carbon source for the bacteria, as air CO2 is usually insufficient.
I wonder if the pepermint, dextrin, starch and sucralose interfere with the bacteria.

At hour 33 I will test for the calcium content of the solution.

Edit:

I tested the calcium content of the solution with sodium carbonate solution. The solution was very slightly cloudy. I don't know if it is the original solution or the reaction that made it cloudy. Result: Inconclusive.
But even if all the urea had bean turned to nitrate, only 0.1% of the solution would be calcium nitrate.

I tested the filtered solution with the oxalate test, it was more precise and some calcium is present in the solution as very slight cloudiness appeared. To get a clearer test the bioreactor must run way longer
[Edited on 18-12-2012 by plante1999]

[Edited on 18-12-2012 by plante1999]

plante1999 - 18-12-2012 at 05:58

Ok, so I have designed two setup. I would want to know which one would be the best. The first one is the currently running one. One is in water medium, and the other would be moist only. both get air from an air stone.

1:

Green is the air stone and the pale blue the tube. The white is calcium carbonate and the black is activated charcoal. Water medium.

2: It is a variant of old nitre bed. The orange is a clay plate and the white potassium carbonate. The purple is calcium carbonate pieces and/or activated charcoal. The set up is only slightly moist and air come from the air pump.

Thanks!

plante1999 - 18-12-2012 at 11:44

Ok, so I found that the antacid contained more than 2 time the weight of calcium carbonate in sugar, starch and other thing like that. To be sure my results were not influenced by the presence of these undesirable compound I made a new colonie in a new medium type.

The plate is made from tera- cotta, onto it there is a calcined calcium carbonate layer onto which the pump is placed. On the pump there is broken seashells. I vaporize dilute urea solution onto the seashell to keep them wet and I added bacteria seed. I hope that calcium nitrate creep out of the plate as crystals.

<iframe sandbox width="560" height="315" src="http://www.youtube.com/embed/jfarUfBYIMQ" frameborder="0" allowfullscreen></iframe>

plante1999 - 19-12-2012 at 11:52

I don't want to spam SM more with my posts. So, if someone is interested by this experimentation, go on the nitrate from ammonia tab of my website. If you have any questions you can ask them on my website. If you want to try please write your experimentation in this thread.

Have a good day!

http://hclo3chem.weebly.com/

watson.fawkes - 19-12-2012 at 12:19

Quote: Originally posted by plante1999

I don't want to spam SM more with my posts.

Experimental progress isn't spam. That remains true even if folks aren't replying with each update. I've been reading, though I have little to say. (Though since I rarely watch video, video updates are mostly the same as no updates for me.)

plante1999 - 20-12-2012 at 05:15

Quote: Originally posted by watson.fawkes

Quote: Originally posted by plante1999

I don't want to spam SM more with my posts.

Thanks for the comment, however I have the feeling I'm spamming SM. I take good note for video. I did a videa because I cannot do good pictures the only camera I have is a webcam, a picture with a webcam is not very good. So you would need to try to imagine whatever I say.

By the way you can still read what I do on my website but here a summary of it:

My new design doesn't have any soluble calcium, but does have a lot of urea. I will wait until the 31 to see if any good result come out of this design. I still think that urea SHOULD be metabolized as most protein breakdown produce urea if a remember, and these bacteria feed on protein waste. Still I will try to find a good ammonium salt for them, without a deranging anion. I will also try to find a more porous media.

watson.fawkes - 20-12-2012 at 05:50

Quote: Originally posted by plante1999

I did a videa because I cannot do good pictures the only camera I have is a webcam, a picture with a webcam is not very good. So you would need to try to imagine whatever I say.

You've involved yourself in communicating chemistry. You'll succeed well only if you can both do chemistry well and communicate well. Part of modern communication is multimedia production. Therefore to further your efforts, balance your budget between chemistry equipment and communications equipment. (In particular, you can go a long way with good lighting and a not-so-great camera.)

plante1999 - 20-12-2012 at 09:51

I bet in the 18th century there was no need for pictures... I will try to find something, but I get something like 100 CAD, just enough to restock my lab, If I get a camera, important reagents would be missing of my lab. Argggg. So anyway, does anyone have an idea of an ammonium salt, which solutions are of pH about 7 and that the anion would not interfere?

[Edited on 20-12-2012 by plante1999]

[Edited on 20-12-2012 by plante1999]

Vargouille - 20-12-2012 at 12:03

Ammonium acetate might be your best bet. Ammonia and acetic acid have the same value for K_b and K_a, respectively, so the pH should be about 7.

EDIT: I'm not sure if acetate will interfere, mind you, so that'll take some testing on your end.

[Edited on 20-12-2012 by Vargouille]

plante1999 - 20-12-2012 at 12:07

Thanks for the idea! However I'm not sure if acetate would kill the bacteria, as they don't support organic material. If I had ammonium nitrate, it would be perfect. I'm wondering why they don't metabolize fast urea, in nature proteins decompose to urea mostly if I remember.

phlogiston - 20-12-2012 at 13:50

Ammonium sulphate and Ammonium chloride are common in bacterial and yeast media.

Vargouille - 20-12-2012 at 14:59

There is some evidence that a Nitrobacter specimen would be fine with acetate. It uses it as a carbon source, apparently. There is also a mention in this article that acetate does not harm Nitrosomonas bacteria, and is also used as a carbon source. This is fortunate because not only is ammonium acetate a (likely) neutral salt of ammonium, but it would appear that it is also compatible with the bacteria.

plante1999 - 20-12-2012 at 15:23

Sound rather good, I just don't want a 30% bi weight acetate in the nitrate produced, but if they metabolize it, it should slowly be used up. At least they are compatible with the salt.

Alright, then I will test using ammonium acetate. First I will need to make some ammonium acetate tough.

plante1999 - 20-12-2012 at 17:49

Urea is slow to metabolize by the bacteria. This may be explained by the very low dissociation into ammonium and cyanate. Even the ammonium must dissociate into ammonia and H+ because the bacteria use only free ammonia. Such low ratio of free ammonia slow the process a lot. Free ammonium salt have a very good dissociation constant, which give very fast conversion to nitrite. However urea might have a very good advantage, it have the ability to make hydrogen bond. As such it can act as a very effective buffer for the medium by making urea nitrate. After some time, this urea nitrate would be metabolized all the way to nitric acid and CO2. More urea would probably bind the nitric acid produced too.

plante1999 - 21-12-2012 at 12:25

When I tested this morning, the pH was 6-7, I do not explain this since the seashells where supposed to neutralize the acid. So I added fee drops of sodium bicarbonate sol. to brink the pH to 8 and then I tried to add one ml of saturated ammonium sulphate. After a few hours the pH was 7 and there was a very slight ammonia smell. This definitively prove that ammonium salts are metabolized WAY faster than urea. Soon I will make ammonium acetate and use it as the ammonium source.

plante1999 - 23-12-2012 at 09:16

From my results of my new design I think I misunderstood what happened in my first design, I made a revision of it, here is it:

Summary of the first 24 hour of run of the bioreactor:

hour 1: Ammonium chloride, sodium bicarbonate, activated charcoal and the bacteria source were added. pH 8

Hour 11: The pH was now 7. First urea addition, 1 ml of 26%. pH 8.

Hour 16: pH 6.5-7. Addition of 1ml of 26% urea and calcium carbonate. Effervescence with the calcium carbonate. pH increase to 8.

Hour 20: pH still 8. Addition of 1 ml urea 26% sol. Calcium carbonate mostly in tiny pieces format.

Hour 22: pH still 8. Addition of 1 ml 26% urea sol.

Interpretation:

Hour 11: The bacteria colonies used some of the ammonium to make nitric acid and most of the bicarbonate was neutralized. When the urea was added, urea nitrate was formed neutralising the acid and increasing pH.

Hour 16: The remaining ammonium was metabolised by the colonies making nitric acid lowering the pH. Calcium carbonate reacted with the nitric acid to yield CO2 and Calcium nitrate, increasing the pH. The calcium carbonate buff the pH to 8. The urea probably did not reacted, or very slightly.

In my last desing I added ammonium sulphate, and I smelled ammonia after a tenth of minutes. I suppose this reaction happened:

(NH4)2SO4 + CaCO3 -) CaSO4 + NH4HCO3 + NH3

I will try ammonium bicarbonate and ammonium actetate. I know a preparation to make the ammonium bicarbonate, but does anyone have another, or have already tried?
Making the odor. I may do two medium at the same time. This product explixitly say that it contain nitrobacter and nitrosonomas:

http://www.fritzzyme.com/index.php?p=fritzzyme-nitrifying-ba...

They also sell ammonium chloride to use when preparing the aquarium with the fritz zyme 7. This prove the content of the bottle. They seams to know what they make, I would probably prefer this product then the walmart one. They also have the concentrated product too which is more interesting for me I will probably buy this too, or something similar:

http://www.ebay.ca/itm/Aquarium-Fish-Tank-Super-Sponge-Bio-F...

And I will probably need something to test nitrates, like this:

http://www.ebay.ca/itm/AQUARIUM-PHARMACEUTICALS-TEST-KIT-NIT...

Does anyone know how I could glue acrylic to terracotta? I will use acrylic to make a square tube and then glue it on a terracotta plate. I will put the bio filter in the square tube and put water. With this set up, it will be easier to make experimentation. I hope, like the second set-up, that crystals of nitrate will creep out of the plate.

watson.fawkes - 24-12-2012 at 18:41

Quote: Originally posted by plante1999

Does anyone know how I could glue acrylic to terracotta?

Epoxy should work. Acrylic is very friendly to chemical adhesives, and terracotta is porous enough that any gap-filling glue should work. Just make sure you have adequate contact area. Add some acrylic flange for extra area of the cross section of the walls of your tube aren't enough.