Sciencemadness Discussion Board - Controlled Bacterial Nitrification (salpeter production, using nitrosomonas etc)

Controlled Bacterial Nitrification (salpeter production, using nitrosomonas etc)

obsessed_chemist - 23-3-2007 at 13:00

Has anyone here ever prepped a fish tank with nitrosomas and nitrobacter bacteria and ammonia to establish the nitrogen cycle before adding fish?

Well, I was thinking, this could be an interesting experiement if done simply to produce nitrates. The pH and temperature have to be carefully maintained, air bubbled in, kept in the dark (for optimal conversion/bacteria growth), etc., but I think it would be fun to give it a try. Clear household ammonia could be used as the main food source for the bacteria, slowly adding until the bacteria count increase exponentially. Apparently these nitrobacter need some phosphate, so I suggest adding a tiny amount of ammonium phosphate as the source. They also need carbonate and bicarbonate. This could be provided with seltzer water if the air pumped in doesn't provide enough. From what I've read, the bacteria will eventually be killed off when the nitrate levels get too high.

I was thinking of maintaining proper temp, pH, ammonia supply, and air until the nitrate level does just that; kills the bacteria. Then the solution can be filtered through diatomaceous earth, leaving primarilly a dirty solution of ammonium nitrate and water. This could then be converted to other nitrates or used as is following purification. In theory, if done correctly, one could have an endless supply of bacteria by making proper cultures. Any thoughts on this?

[Edited on 3/23/2007 by obsessed_chemist]

Edit by Chemoleo: Title and thread merge.

[Edited on 29-10-2008 by chemoleo]

Levi - 23-3-2007 at 16:25

I expect it would be 10-20 months before you could harvest the nitrate but it would certainly work. Of course if you had 10-20 tanks you could be harvesting continually =)

S.C. Wack - 24-3-2007 at 04:53

The stated yield in 100+ year old research (aimed at assuring Chile-dependent France of nitrate should the Kaiserliche Marine cause problems) at 24 hours for 1 cubic meter of peat-supported nitrifying bacteria at 30C was 6.55 kg "nitrate" (probably calcium); probably using 7.5 g/L ammonium sulfate with passes through beds in succession with fresh sulfate added to the flush water, and lime to bind the sulfate. I'm sure that there is research out there in aerated solution where results (nitrite/nitrate) were measured in hours or days rather than months.

Levi - 24-3-2007 at 14:51

Hours!? I found a site a while back which discusses the construction of nitre beds (link supplied below) but all harvest times are greater than 1 year. If the aqueous method does indeed work in a matter of hours this would be an economical way to produce nitrates on a massive scale for industry.

http://docsouth.unc.edu/imls/lecontesalt/leconte.html

12AX7 - 24-3-2007 at 16:08

Active aeration does better than straw and poo...

Still sounds awfully fast, but I would believe the rate can be pretty good.

Seems to me an ion exchange resin that preferrentially picks up nitrates would be of use here.

Tim

saltpeter/HNO3 from urea + bacteriae

chief - 27-10-2008 at 08:08

With nitrates possibly getting banned from the hardware-store-fertilizer shelves, another sort of N-fertilizer is already available, as "substitute":

Urea ! Fine, since this is what the source of saltpeter was for centuries. In the past times it were stinking saltpeter-plantages, because the sources of the urea were excrements from human/animal-sources.

Today this might be had much cleaner: Just only some reactor, some stirring, the right bacteriae . At least it doesn't consume electicity like the birkeland-eyde-reactor ...

Although I have no exact Idea about how I would start this, probably It could work like this:
==> since it's a aerobic process: Air must reach the stuff
==> maybe some source of nutrition for the bacteriae, that contains the right minerals (since they may need something else besides the urea)
==>some temperatureabove 20 [Celsius]

Maybe the urea-solution might be rinsed over clay-granulate (for hydro-cultures) ? This would give a high liquid-air-surface ...

As I understand the ancient technique: They "harvested" the saltpeter off like "off the wall": Just scratched the white stuff fromwhere it appeared. So this can be built into the reactor: Where a lot of evaporation occurs, there always fresh solution is transported to, giving off the H2O and leaving the salts in place ...

The only question is: Where to get the bacteriae and how to meet their living-conditions best ....

[Edited on 27-10-2008 by chief]

Foss_Jeane - 27-10-2008 at 11:44

I wouldn't do it that way. Back in the good ol' days, they really didn't have much choice. That manure/urine/bacteria method will stink to high heaven, making you real popular with the neighbors, and it takes a dog's age. It is also hardly discreet. Purification of the resulting nitrates is also going to be problematic (you don't want sh!t in your saltpeter, do you?).

Better to use the electrical method: strike an arc, pass in air (fortify with O2 if you can) collect the nitrogen oxides. If you can stand some nitrite in the mix, you can also pass it straight into a basic solution until neutralized.

Anyway, that's how I would do it, although it's hardly necessary since I can find lots of products on the hardware shelf from which one can always extract nitrates.

[Edited on 27-10-2008 by Foss_Jeane]

Formatik - 27-10-2008 at 14:02

You can use urea to form potassium cyanate. This is done by heating urea with KOH around 240 deg. for 3-5 hours: KOH + 2 CO(NH2)2 -> (KCNO)x + 3 NH3 + CO2 (see USP 3935300). K2CO3 also works.

Air will oxidize KCNO in the presence of catalysts like Ag-powder, CuO, or NiO to form KNO3. NO also oxidizes KCNO without a catalyst above 210 deg. Even KClO3 which is diluted with CaO or Na2CO3 due to explosion risk will oxidize KCNO to KNO3 (Ber. 59, [1926] 204).

jimmyboy - 27-10-2008 at 14:44

Urea slowly converts to ammonia then to nitrates by bacteria - even with optimum conditions - temperature - PH - moisture this reaction takes a dogs age and the yields will be horrible - you need pressure and heat and catalyst to drive the oxidation of ammonia - if you really are stuck without any nitrates where you live then you should invest in metal catalysts to oxidize your own ammonia to nitrites and go from there - it will be slow but way faster than waiting years for urea to be converted by bacteria

chief - 27-10-2008 at 14:54

Quote:

Originally posted by Formatik
You can use urea to form potassium cyanate. This is done by heating urea with KOH around 240 deg. for 3-5 hours: KOH + 2 CO(NH2)2 -> (KCNO)x + 3 NH3 + CO2 (see USP 3935300). K2CO3 also works.

Air will oxidize KCNO in the presence of catalysts like Ag-powder, CuO, or NiO to form KNO3. NO also oxidizes KCNO without a catalyst above 210 deg. Even KClO3 which is diluted with CaO or Na2CO3 due to explosion risk will oxidize KCNO to KNO3 (Ber. 59, [1926] 204).

This seems the way to go then, since everybody has a chlorate-cell anyhow ! How high would have the temp to be ? What details are available ? Urea is available by the kg-amounts as fertilizer in Germany here !
How poisonous is the cyanate ?

Would it work with the much more available sodium-compounds (Na2CO3, NaClO3) ?

[Edited on 27-10-2008 by chief]

kclo4 - 27-10-2008 at 15:17

Check out this if you haven't already: http://docsouth.unc.edu/imls/lecontesalt/leconte.html

Every time I read it It makes me want to do it, but then I realize I have a plentiful amount of Nitrate... relatively. Looks fun though, Especially if you could dope it with Urea to increase yield a lot.

S.C. Wack - 27-10-2008 at 16:11

Dirt. I bet if you watered some dirt with a solution of urea in the summer, you'd soon have a lot of organisms busy converting urea to ammonia, and/or turning ammonia into nitrate. I think it unlikely to take years. I'm aware of some French research a long time ago claiming rapid and exothermic conversion of fairly large amounts of ammonia into nitrate by nitrifying bacteria under somewhat controlled conditions, (maybe there is lots of study done to be found if you research the subject) and why not just make your own urease while you're at it.

If the process was slow, then urea would be pretty useless as a fertilizer. It is decomposed so quickly by soil urease that urease inhibitors have been extensively researched, to retard ammonia loss by volatilzation.

kclo4 - 27-10-2008 at 16:30

If I were to do it with what I know at this moment, I would probably buy some manure and mix it with urea, ash, and a large amount of vermiculite or pertlite, and perhaps some other things to help keep the O2 in it. Then I'd always keep it moist in a a warm spot.
I'd probably want to fill a black garbage can half full so it would allow me to agitate the mixture often to mix in more air, and then also since its black it can absorb the heat from the sun which would likely speed up the reaction.

Extracting the Nitrates from that might be a bit tricky.

One Idea would be to use a terracotta pot, with the same mixture (manure, urea, vermiculite) and also always keep it warm and moist.
But with this, the terracotta pot could have water slowly added to it, allowing the Nitrate to dissolve, and go to the outside of the pot. As the water dries the nitrate would form a white crust on the pot. That is, if the ions would travel through the material.

It actually seems like a lot more work then I had realized at first to get significant amounts.
However, when I own my house I'll probably make one of these just for the heck of it. Seems like it would be pretty neat to have.

chemoleo - 27-10-2008 at 17:57

Please check also this.

https://sciencemadness.org/talk/viewthread.php?tid=3986

I'll leave this as a separate thread as the approach taken is different.
It would be interesting if this could lead to efficient production of nitrates!

The_Davster - 27-10-2008 at 18:15

http://www.geocities.com/CapeCanaveral/Lab/1121/KNOstory.htm...

Why not use something like this, with added urea...should be able to get the nitrifing bacteria out of the ground and simply add urea.

not_important - 27-10-2008 at 21:23

OK, Nitrosomonas oxidise ammonia to nitrite in several steps, Nitrobacter take nitrite to nitrate.

These bacteria use CO2 as their carbon source, and also as a source of oxygen for oxidising the nitrogen compounds although they still need molecular oxygen.

Having reduced forms of carbon around, as from mixing manure into your culture, feeds the denitrifying bacteria which convert nitrate to N2 and reduce your yields. I would say that mixing manure or soil into your system is not the best idea.

The buggers you want like a temperature range of 25-30°, the optimum pH range for Nitrosomonas is between 7,8-8,0 while for Nitrobacter it is between 7,3-7,5. They don't like light, take that into consideration. They will need a trace amount of phosphate, ordinary tap water contains enough of the other needed trace elements.

You can buy mixed cultures of nitrifying bacteria. Ones like http://www.fritzpet.com/fritz-zyme-7/ include species than can directly utilise urea, instead of letting some other bacteria hydrolyse it.

These are slow growing bacteria, often taking the better part of a day to double in population. So you will have a very slow startup, and you want to leave solid culture support behind when harvesting nitrate, so as to have a good culture to continue with.

Formatik - 27-10-2008 at 22:55

Quote:

Originally posted by chief This seems the way to go then, since everybody has a chlorate-cell anyhow ! How high would have the temp to be ? What details are available ? Urea is available by the kg-amounts as fertilizer in Germany here !
How poisonous is the cyanate ?

Would it work with the much more available sodium-compounds (Na2CO3, NaClO3) ?

That reference will likely have more details. I've only looked into the potassium salts. Cyanate is known to be about 1000 times less poisonous than cyanide.

I would try the less hazardous oxidation routes first. But if you are starting from KClO3, then heating KClO3 to 220 deg. it will react exothermically with NH3: 3 KClO3 + 2 NH3 = 2 KNO3 + KCl + Cl2 + 3 H2O. By a good spread of the KClO3 and with careful heat regulation, a yield of 60% can be obtained. This process and reaction is described in Ber. 57 [1924] 818. The NH3 likely has to be dry.

chief - 28-10-2008 at 01:15

Quote:

Originally posted by Formatik
The NH3 likely has to be dry.

By NH3 you mean urea ?

[Edited on 28-10-2008 by chief]

12AX7 - 28-10-2008 at 12:21

KClO3 burns tepidly with (NH2)2CO. I don't think I've ever ignited a properly stoichiometric mixture, but it sure isn't going to be flash powder, no matter what ratio it's in. It may be a viable route to nitrates, since chucking stuff into a bucket doesn't work so hot.

Tim

chief - 28-10-2008 at 15:01

If this holds:
3 KClO3 + 2 NH3 = 2 KNO3 + KCl + Cl2 + 3 H2O
(@220 [Cels]), then how to get the NH3 from the urea ? (I never was into organics such "uninteresting" as urea)
Maybe I just could heat the NaClO3 in the furnace to 200 [Cels] and then stream NH3 throug it, watching the temp ?
If NH3 is oxidized by chlorate, could there be a direct electrolytic route (under avoidance of the explosive "Dulong Oil" NCl3), like eg.. giving NH3 to a chlorate cell ?

kclo4 - 28-10-2008 at 15:35

It might work, but why not just oxidize the NH3 with air to produce HNO3?
That reaction isn't all that hard especially if you can improvise a nice catalyst.
I know a flask full of NH3 and Air plus a hot copper wire can produce White smoke, which if i remember correctly is Ammonium Nitrxtes.

Urea is actually pretty interesting, and you can produce Ammonia by adding a base, or by heating it. A base will produce water, Ammonia and a Cyanate. The cyanate could later be oxidized to a nitrate later.

Would a hypochlorite do anything to a cyanate? Seems like it might possibly make a nitrate copper oxide and a cyanate can.

Formatik - 28-10-2008 at 15:36

I don't know how much I trust urea here. Urea decomposes to varying organic compounds when heated all while releasing NH3 and H2O. I don't trust it because NH4ClO3 formation has not been ruled out. NH4ClO3 can deflagrate or burn with a red flame when heated, but it can also detonate, it is known for spontaneous explosions, even when wet with water it is an explosion risk. The only thing Gmelin mentions about this is that urea heated with NaClO3 causes ignition at the melting point of NaClO3, which doesn't say much.

S.C. Wack - 28-10-2008 at 16:16

Well there seems to be some interest, though not necessarily in this thread, and there seems to be some doubt. So if someone wants to try to duplicate the work that I've mentioned, these are the 1905-1906 Compt. rend. (Gallica) articles that I was talking about above.

There is also a 136 page article by the same authors in Ann. chim. phys. (8) 11, 439 (1907)

[Edited on 28-10-2008 by S.C. Wack]

Attachment: nitrification.pdf (998kB)
This file has been downloaded 2103 times

kclo4 - 28-10-2008 at 17:19

This is just like the other threads. Perhaps it wouldn't be a bad idea to merge this one with the other active one? I don't know be nice just to have all of the references, ideas and what not all together I guess.

I wish I could read whatever the hell language that is! haha ok, well I can understand it a little bit, but not enough.

We seem to be spitting out every idea about making nitrates from Bacteria and what not, lets not forget about using peas, or beans or whatever other sort of thing that has nitrogen fixing bacteria on its roots. I think you could almost get Nitrates out of thin air this way! Bubbling water into a "hydroponic" like set up with peas growing in it + nutrients for the bacteria as well as the plant. The plants bacteria react with atmospheric nitrogen to produce ammonia. The ammonia could then be oxidized to nitrate with the other bacteria. Perhaps you could get the bacteria from the pea roots to get established with out the need of the pea. This would be nice since I believe plants need a relatively low ppm of nutrients to live hydroponically.

Perhaps putting a porous material on the side of the "tank" where the water meets would allow nitrate crust to form. All you'd need to do then is scrape of the milligrams every week and purify it

Edit: http://www.cahe.nmsu.edu/pubs/_a/a-129.pdf after reading that, my Pea idea doesn't seem all that great to me.

Does anyone know what percent of Nitrate kills them at? I think that is really an important factor when it comes to determining if it would be worth doing a liquid culture.

I had read that it can get as high as 1000ppm in aquariums, But I bet it could go a ton higher.
Assuming they are only counting NO3- for the ppm and not the K+, you can get about 1.6 grams of KNO3 from every liter of water right?

[Edited on 28-10-2008 by kclo4]

not_important - 28-10-2008 at 21:26

The levels of combined nitrogen from nitrogen fixing bacteria is low, on the order of 75 to 300 kilograms of N per hectare per year for symbiotic bacteria growing in legume roots, about 1/100 of those values in the case of free-living bacteria. The low fixing rates is why development of synthetic fixed nitrogen was so important.

For legumes almost all the fixed nitrogen is trapped by the plant for conversion into amino acids, not released into the soil. This is also true for many of the non-symbiotic free living bacteria, the nitrogen they fix is stored as proteins and other organic compounds within the bacteria and become available to plants after the bacteria die.

The fixing process is poisoned by oxygen, in legumes the bacteria live within the plants roots, many of the free living bacteria need anaerobic conditions although some others do tolerate oxygen. The nitrification process requires oxygen.

The limiting concentrations of nitrite and nitrate for the bacteria are quit low, I believe around 10 to 20 mg/l There's a bit of a discussion in this PDF https://dspace.lib.cranfield.ac.uk/bitstream/1826/1021/3/Din...

kclo4 - 29-10-2008 at 16:05

It has to be more then 20mg/L (aka 20ppm) since the problem with fish tanks is that it can get to high (past 100ppm) that is 100mg/L. I am doing the ppm conversion correctly right?

not_important - 29-10-2008 at 16:49

NO3 is much heavier than H2O, it's not a 1:1 equivalence.

The conversion of nitrate to nitrogen, by denitrifying bacteria, shuts down before the nitrifying bacteria do. The production of nitrate starts to slow down in the 10 to 20 range, but may continue increasingly slowly to higher concentrations, from what I read. As conversion is slow anyway, pushing into the still slower range seems to be less than desirable.

kclo4 - 29-10-2008 at 19:14

Oh I see, so I have done the ppm(mg/L) to grams wrong?
could you explain to me how exactly it is done then?

Formatik - 1-11-2008 at 09:10

I've got some more info on the oxidation of KCNO, but I don't know how well this side discussion fits in this thread mostly covering nitrification reactions.

I've included the bit about KCN for saftey reasons, it needs sufficient air. Heating to 700 to 900º (2-4 hrs) KCNO partially converts to KCN. The maximum of KCN (per 100 g reaction product) is 53.08 g KCN is obtained after 2 hrs at 900º (C.r. 161 [1915] 308).

About 3 hours heating of KCNO in a well dried stream of air oxidizes it to KNO3, the oxidation is accelerated through catalysts such as metallic Cu, Ni, Ag, Au or their salts, as well as traces of moisture in the air stream, where KCNO is primarily split into easily oxidizable NH3 and K2CO3 (Ber. 59 [1926] 210).

chief - 8-11-2008 at 06:48

I now found: The N-content of _peas_ is 6.25 %; also in big amounts (25 kg) they should be very cheap (50 % more expensive than wheat)
==> everybody may have seen, how quickly a pea-soup is gonna be the breeding ground of zillions of bacteriae !
The stuff contains maybe averything that any microorganism might like, so:
Why not make a pea-soup (100 l), give the right bacteriae into it and see the result ?

Unfortunately I have _no_ experience in anything microorganism-related, so I wouldn't know how to find the right bacteriae, but probably from where they should occur in nature ...

kclo4 - 8-11-2008 at 19:57

Quote:

Originally posted by Formatik
I've got some more info on the oxidation of KCNO, but I don't know how well this side discussion fits in this thread mostly covering nitrification reactions.

I've included the bit about KCN for saftey reasons, it needs sufficient air. Heating to 700 to 900º (2-4 hrs) KCNO partially converts to KCN. The maximum of KCN (per 100 g reaction product) is 53.08 g KCN is obtained after 2 hrs at 900º (C.r. 161 [1915] 308).

About 3 hours heating of KCNO in a well dried stream of air oxidizes it to KNO3, the oxidation is accelerated through catalysts such as metallic Cu, Ni, Ag, Au or their salts, as well as traces of moisture in the air stream, where KCNO is primarily split into easily oxidizable NH3 and K2CO3 (Ber. 59 [1926] 210).

I doubt heating KOCN produces KCN. How would it?
With a reducer, of course.. but by itself? Seems unlikely.
I know KCN is oxidized in the air to KOCN.

Oh yeah, and I do like the Idea of oxidizing KOCN into KNO3, Any idea on how hot it would have to get?

[Edited on 8-11-2008 by kclo4]

Formatik - 8-11-2008 at 20:20

That bit about KCN is just heating by itself. I don't know what temperatures are needed since I haven't looked at the references, my likely guess is between 200 to 500º.

kclo4 - 14-11-2008 at 17:07

I think at those tempuratures you might have problems with KNO3 decomposing, but perhaps not

400 °C is the decomposition temperature of KNO3, if it decomposes at those temperatures, I imagine it would be very hard to form it around those temperatures as well.

Formatik - 24-5-2009 at 12:59

Quote: Originally posted by Formatik

About 3 hours heating [at 400 deg.] of KCNO in a well dried stream of air oxidizes it to KNO3, the oxidation is accelerated through catalysts such as metallic Cu, Ni, Ag, Au or their salts, as well as traces of moisture in the air stream, where KCNO is primarily split into easily oxidizable NH3 and K2CO3 (Ber. 59 [1926] 210).

The yields by this method are disappointing for sure, type of catalyst has an influence and with Ag powder the yield was highest at 22% of the nitrogen and slightly moist air, compared to Cu, Ni powder or their compounds. Oxidizing KCNO with KClO3 which has to be diluted with Na2CO3 or CaO (to avoid explosion) gets a better yield of 37.4% of the N, but still quite low. Another method uses CaCN2. Technical CaCN2 heated with Na2CO3 and small amount of catalyst under stirring under moderatley fast air stream at 400 deg., converts "the largest part" of the bound nitrogen to nitrate (DE439510). I've also got the Ber. 59 [1926], 204-212 ref., it's in my profile. It's quite interesting. Oxidizing CaCN2 or urea with solid inorganic peroxides has potential as the nitrate yield is modestly high, though requires large amounts of peroxides, e.g. deflagration of CaCN2 with Na2O2 gets 65% of the N yield.

Attachment: DE439510.pdf (79kB)
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[Edited on 24-5-2009 by Formatik]

S.C. Wack - 24-5-2009 at 13:41

I see that the <1 MB pdf attachment on my last post has disappeared somehow. That's not a good sign. Not only can I not upload pdfs, old ones are disappearing....

While I'm here, a working link to the Gallica article (long, old, French), since Gallica has changed some lately and the link I gave before is not so great now
http://gallica.bnf.fr/ark:/12148/bpt6k34941m.image.f431

Big Boss - 12-8-2015 at 13:43

I'm running an experiment at the minute where I have gotten some of soil, added 0.75% NH4Cl sol to it and let the bacteria reproduce for a few days in some soil, then after about 3 days I washed the soil with more NH4Cl sol and transferred it to a 2L bottle with 1L of 0.75% sol in it.
I added powdered CaCO3 to it to neutralise any Nitric Acid formed during the process forming Calcium Nitrate.
I added an aquarium bubbler to it. So far it has been 2 days and this morning I took a small sample of the liquid and added NaOH solution to it, of course I could smell Ammonia indicating that all of the NH4Cl has not been fermented yet, however I also got a very fine precipitate of presumably Ca(OH)2.
The bacteria apparently take days to reproduce, they must consume a lot of ammonia before doing so.

Melgar - 12-9-2016 at 11:44

Actually, nitrate-selective ion exchange resin would be perfect for this project. It's already a mass-produced commodity, and can be reused indefinitely.

nitrifying bacteria

10fingers2eyes - 23-1-2017 at 14:49

I am in the midst of trying this using aquarium bacteria to produce nitrates from urea. My set up is a 5 gallon jug with a small aquarium air pump, small aquarium heater (82F) and moving bed filter media to maximize surface area for the bacteria to grow on. It takes at least a week or two just to get enough bacteria growing to get the moving bed media to circulate. I have been running for 6 weeks now and I have a positive test for at least a few grams of nitrates, it is just starting to barely indicate on a brown ring test, very slow but most of the time has been bacteria colony establishment at this point. I feed it about 5 g of urea a day and have some trace nutrients initially like phosphate, potassium, iron, calcium and magnesium. Urea is good food because the bacteria can hydrolyze it and use the CO2 for a carbon source as well. Getting enough oxygen to dissolve at some point might be a problem.

Tsjerk - 24-1-2017 at 04:31

Any idea what species you have growing in there?

Edit:

Quote:

Wiki: Nitrification inhibitors are chemical compounds that slow the nitrification of ammonia, ammonium-containing, or urea-containing fertilizers, which are applied to soil as fertilizers. These inhibitors can help reduce losses of nitrogen in soil that would otherwise be used by crops. Nitrification inhibitors are used widely, being added to approximately 50% of the fall-applied anhydrous ammonia in states in the U.S., like Illinois.[16] They are usually effective in increasing recovery of nitrogen fertilizer in row crops, but the level of effectiveness depends on external conditions and their benefits are most likely to be seen at less than optimal nitrogen rates.[17]

Are you sure your urea doesn't contain an inhibitor?

[Edited on 24-1-2017 by Tsjerk]

[Edited on 24-1-2017 by Tsjerk]

Σldritch - 23-11-2017 at 06:53

I am currently growing bacteria in 30L of tap water and 500ml of granulated urea and three flower food sticks for phosphorous and micronutrients. It is hard to tell if it has changed but it strongly smells of ammonia so i think something is happening in there.

How concentrated amonium nitrate solution can the bacteria survive in?

There is this source but i have no idea if it is accurate: http://www.bioconlabs.com/nitribactfacts.html

[Edited on 23-11-2017 by Σldritch]

NEMO-Chemistry - 26-11-2017 at 14:50

Once Nitrate reaches a certain level, Nitrosomas uses it and starts to reverse it back to Nitrite and Ammonia. There is a paper somewhere on my pc about it.

Σldritch - 27-11-2017 at 10:34

Do they really if the suspension is still aerated? They should gain no energy from that, right? Maybe something will start oxidizing the dead cells for energy or something photosynthetic starts growing in but that should not be a problem.

Metacelsus - 27-11-2017 at 14:24

Bacterial nitrate reduction primarily happens under anaerobic conditions (at least for the Rhodobacterales, which are the most important for this, and probably for all the other denitrifying bacteria as well). Under aerobic conditions, oxygen is preferentially used as a terminal electron acceptor, although a small amount of denitrification can also happen.

NEMO-Chemistry - 27-11-2017 at 16:02

Quote: Originally posted by Metacelsus

Bacterial nitrate reduction primarily happens under anaerobic conditions (at least for the Rhodobacterales, which are the most important for this, and probably for all the other denitrifying bacteria as well). Under aerobic conditions, oxygen is preferentially used as a terminal electron acceptor, although a small amount of denitrification can also happen.

The paper is on the laptop or would be easier to find, i kept it because i keep fish. Now its one paper, and it goes against everything i ever thought about filtration and fish.

I had always assumed anaerobic conditions and different bacteria to revert Nitrate. But i will search it out, i would be extremely interested to get real chemists opinions on the paper.

From memory it was Nitrosomas (99% sure) and aerobic (85% sure). I cant remember the conditions needed but i was more than surprised. Personally I have doubts, but as soon as i dig it up i will post.

My first thought i admit was, total tosh. But let me find it and see what you think.

I dont have mendeley on the laptop, which is a PITA, but a quick look found this..

http://eawag-bbd.ethz.ch/nit/nit_map.html

This however is not what i found in the other paper. But until i find it again, maybe someone can spot something that makes sense in what I was saying.

The link is on about anaerobic conditions, however I am positive the other paper mentions aerobic conditions and very high levels of Nitrate.

[Edited on 28-11-2017 by NEMO-Chemistry]

Metacelsus - 28-11-2017 at 06:33

Quote: Originally posted by NEMO-Chemistry

From memory it was Nitrosomas (99% sure) and aerobic (85% sure). I cant remember the conditions needed but i was more than surprised. Personally I have doubts, but as soon as i dig it up i will post.

Nitrosomonas (not "Nitrosomas") will oxidize ammonia to nitrite. Nitrobacter can then oxidize the nitrite further to nitrate. These processes happen only when oxygen is present.

If both nitrite and ammonia are present simultaneously under anaerobic conditions, then some bacteria can convert them both to nitrogen gas (this is known as anaerobic ammonia oxidation).

Denitrifying bacteria, such as Paracoccus, use nitrate for anaerobic respiration and reduce it to nitrogen gas. They do this primarily under anoxic conditions.

My source for all this information is my Microbiology textbook (Prescott's, 9th edition).

Also, I can't load the site you linked to in the post above.

Edit: I found it on the web archive.

[Edited on 11-28-2017 by Metacelsus]

NEMO-Chemistry - 28-11-2017 at 06:39

Quote: Originally posted by Metacelsus

Quote: Originally posted by NEMO-Chemistry

From memory it was Nitrosomas (99% sure) and aerobic (85% sure). I cant remember the conditions needed but i was more than surprised. Personally I have doubts, but as soon as i dig it up i will post.

Sorry excuse my spelling.
I am aware of the normal way it works, as i said above the paper goes against everything i have read on it. The only other information i found was the link above (i will try and find another).

The problem with the above link is it is Anaerobic. Dont shoot the messenger!

, i am more interested in what people make of the paper. Thats why i have avoided the whole what organism is actually responsible debate

.

I have asked around on a couple of fish forums i am on, no one knows anything about the paper..... Starting to hope i find it or a reference for it.

Link opens fine for me! But i have recently changed DNS servers because of 'other' issues...

[Edited on 28-11-2017 by NEMO-Chemistry]

NEMO-Chemistry - 30-11-2017 at 20:10

Cant find this paper at all now, so i withdraw what i said until i can back it up. Really annoying as it would have made a great subject to discuss! but without the paper its just he said/ she said waffle. Sorry guys I was sure i knew where the paper was.