DIY Sulfur Denitrator
- Thread starter JohnL
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Why does the PH raises to a normal value when the low oxygen effluent is aerated?
PH is driven by CO2 not oxygen.
Aeration increases gas exchange and will equilibriate the CO2 level with the surrounding air. If the air in the room is at normal atmospheric levels( around 399ppm , IIRC) the CO2 level in the aerated water will rise or fall to that level over a period of time.,usually and hour or two depending on the amount of aeration. In sea water this averages around pH 8.1/8.2.
Aeration also equilbrates O2 which may edge the bacterial activity away from NO3 in favor of the free oxygen.
I think rclendan is trying to see whether a CO2 limitation for T. nitrificans is occuring in a low flow environment without upping the O2 as would occur with aerationvs CO2 injection.
PH is driven by CO2 not oxygen.
Aeration increases gas exchange and will equilibriate the CO2 level with the surrounding air. If the air in the room is at normal atmospheric levels( around 399ppm , IIRC) the CO2 level in the aerated water will rise or fall to that level over a period of time.,usually and hour or two depending on the amount of aeration. In sea water this averages around pH 8.1/8.2.
Aeration also equilbrates O2 which may edge the bacterial activity away from NO3 in favor of the free oxygen.
I think rclendan is trying to see whether a CO2 limitation for T. nitrificans is occuring in a low flow environment without upping the O2 as would occur with aerationvs CO2 injection.
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rclendan
New member
Thanks for your help...
Interesting, I hadn't though of reducing, hypoxic areas forming in the bacterial mats themselves. This could be the source of the denitrication caused by the sucrose. If this is the case, these bacteria are very efficient. I can more than double my flow rate (from 1.5 liter/hr to 4.0 liters/hr) when organic carbon is added.
Interesting, I hadn't though of reducing, hypoxic areas forming in the bacterial mats themselves. This could be the source of the denitrication caused by the sucrose. If this is the case, these bacteria are very efficient. I can more than double my flow rate (from 1.5 liter/hr to 4.0 liters/hr) when organic carbon is added.
rclendan
New member
Yes. my hypothesis is that our S. denitrators are Carbon limited, all other conditions being equal. In order to determine this I need to verify that other heterotrophic species aren't joining the party. So I either need to control for them by running a reactor without sulphur (just an equal amount of aragonite), or run a completely inorganic test setup with just potassium nitrate solution as a test standard, carbon dioxide, and inoculated sulphur media.
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You are welcome.
The heterotrophic bacteria grow fast when organic carbon is around and other nutrients( P, N ,Fe, K et al) are sufficient. They are also pretty good at grabbing significant inorganic phosphate.
Just to illustrate the efficiency, I've been dosing soluble organics (ethanol/aka vodka and acetic acid/aka vinegar in moderate amounts for over 5.5 years) directly to a high flow area in the sump of the main 650 gallon system which houses a wide variety of corals mostly sps but many others including non photosynthetic species. The system houses over 50 fish and is heavily fed. PO4 holds in th 0.02ppm to 0.04ppm range with NO3 between 0.2ppm and 1ppm. Skimming and a small amount of Rox granualted activated carbon are in play but no GFO or other adsorbents.The sulfur reactor for this system is not in use.
You might find this power point presentation of interest:
http://ag.arizona.edu/azaqua/ista/ISTA7/RecircWorkshop/Workshop%20PP%20%20&%20Misc%20Papers%20Adobe%202006/7%20Biofiltration/Microbial%20Floc%20Systems/2006%20Roanoke%20-%20Understanding%20Trophic%20Systems%20%20Ebeling.pdf
This thread of mine includes a lot of information regarding organic carbon dosing from a broad group of folks and a few citations of studies that you may find useful :
http://www.reefcentral.com/forums/showthread.php?p=23138594&highlight=ammonia#post23138594
To be clear this post is not intended to suggest organic carbon dosing is "better" than a sulfur denitratror for nitrogen reduction but rather to provide background on the effects of organic carbon dosing as you seem to be considering some combination(s).
They do produce CO2 and it might be possible to for them to coexist in a good balance with sulfur bacteria but they might dominate.
The heterotrophic bacteria grow fast when organic carbon is around and other nutrients( P, N ,Fe, K et al) are sufficient. They are also pretty good at grabbing significant inorganic phosphate.
Just to illustrate the efficiency, I've been dosing soluble organics (ethanol/aka vodka and acetic acid/aka vinegar in moderate amounts for over 5.5 years) directly to a high flow area in the sump of the main 650 gallon system which houses a wide variety of corals mostly sps but many others including non photosynthetic species. The system houses over 50 fish and is heavily fed. PO4 holds in th 0.02ppm to 0.04ppm range with NO3 between 0.2ppm and 1ppm. Skimming and a small amount of Rox granualted activated carbon are in play but no GFO or other adsorbents.The sulfur reactor for this system is not in use.
You might find this power point presentation of interest:
http://ag.arizona.edu/azaqua/ista/ISTA7/RecircWorkshop/Workshop%20PP%20%20&%20Misc%20Papers%20Adobe%202006/7%20Biofiltration/Microbial%20Floc%20Systems/2006%20Roanoke%20-%20Understanding%20Trophic%20Systems%20%20Ebeling.pdf
This thread of mine includes a lot of information regarding organic carbon dosing from a broad group of folks and a few citations of studies that you may find useful :
http://www.reefcentral.com/forums/showthread.php?p=23138594&highlight=ammonia#post23138594
To be clear this post is not intended to suggest organic carbon dosing is "better" than a sulfur denitratror for nitrogen reduction but rather to provide background on the effects of organic carbon dosing as you seem to be considering some combination(s).
They do produce CO2 and it might be possible to for them to coexist in a good balance with sulfur bacteria but they might dominate.
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Belgian Anthias
New member
Why does the PH raises to a normal value when the low oxygen effluent is aerated?
PH is driven by CO2 not oxygen.
Aeration increases gas exchange and will equilibriate the CO2 level with the surrounding air. If the air in the room is at normal atmospheric levels( around 399ppm , IIRC) the CO2 level in the aerated water will rise or fall to that level over a period of time.,usually and hour or two depending on the amount of aeration. In sea water this averages around pH 8.1/8.2.
If the effluent has a PH of 7.6 and raises to 8.1 just by aerating the water this must mean that there was a lot of CO2 present in the effluent causing the low PH because the effect of H+ on PH was already eliminated by CaCO3 + H+ -> Ca+2 + HCO3- in the calcium-reactor or am I wrong?
PH is driven by CO2 not oxygen.
Aeration increases gas exchange and will equilibriate the CO2 level with the surrounding air. If the air in the room is at normal atmospheric levels( around 399ppm , IIRC) the CO2 level in the aerated water will rise or fall to that level over a period of time.,usually and hour or two depending on the amount of aeration. In sea water this averages around pH 8.1/8.2.
If the effluent has a PH of 7.6 and raises to 8.1 just by aerating the water this must mean that there was a lot of CO2 present in the effluent causing the low PH because the effect of H+ on PH was already eliminated by CaCO3 + H+ -> Ca+2 + HCO3- in the calcium-reactor or am I wrong?
Belgian Anthias
New member
it is a fact that a carbon based anaerobe de-nitrator is a lot more effective than a sulfur based de-nitrator for the same volume. The main reason for wastewater and drink water factory's to change to a sulphur based system is +- 50% less waste product for the same nitrate reduction an less maintenance .
When in a sulfur-denitrator carbon is dosed it will become a carbon denitrator and the presence of T. nitrificans will be very limited if at all present. This is when the oxygen level is low enough for heterotrophe de-nitrification. It is remarkable that the flow can increase when adding carbon because the opposite could be expected because the oxygen level for autotrophe de-nitrification may be a lot higher so more oxygen, more flow, can be entered. The reason can be that the population of aerobe bacteria is caused to increase a lot removing oxygen faster.. Those bacteria will also take up nitrate in there tissue as they grow which will be released again when they die. This means that dosing carbon must be accurate to keep them alive and prevent overcrowding. They will not find enough food in the water or on the sulfur when dosing is stopped or interrupted.. The same for the anaerobe heterotophe bacteria. Once the balance is found flow corrections or changes of nitrate levels and carbon dosing must be limited because big changes will kill the beast.
By adding carbon to a sulfur denitrator all the advantages of BADESS wil be lost as there are: maintenance free, easy flow regulation, easy control over the desired nitrate level in the system, easy management, reliability, and so on.
When in a sulfur-denitrator carbon is dosed it will become a carbon denitrator and the presence of T. nitrificans will be very limited if at all present. This is when the oxygen level is low enough for heterotrophe de-nitrification. It is remarkable that the flow can increase when adding carbon because the opposite could be expected because the oxygen level for autotrophe de-nitrification may be a lot higher so more oxygen, more flow, can be entered. The reason can be that the population of aerobe bacteria is caused to increase a lot removing oxygen faster.. Those bacteria will also take up nitrate in there tissue as they grow which will be released again when they die. This means that dosing carbon must be accurate to keep them alive and prevent overcrowding. They will not find enough food in the water or on the sulfur when dosing is stopped or interrupted.. The same for the anaerobe heterotophe bacteria. Once the balance is found flow corrections or changes of nitrate levels and carbon dosing must be limited because big changes will kill the beast.
By adding carbon to a sulfur denitrator all the advantages of BADESS wil be lost as there are: maintenance free, easy flow regulation, easy control over the desired nitrate level in the system, easy management, reliability, and so on.
rclendan
New member
Tom,
Thanks for the pdf. great info. Nice perspective on holistic nutrient control.
That's a big tank. Glad to hear of your success. I have read many Carbon dosing success stories. I have been carbon dosing for some time (3 years) with limited results (vinegar / kalk top off water). It kept my phosphates very low, but nitrates still climbed. I have a remote DSB and that also doesn't seem to keep up with the nitrogen load. I have tried algal turf scrubbers, they were way more work and trouble than they were worth. The only passive nitrate control method I have had some success with was a DSB in my old main display tank that maintained near zero nitrates for about 10 years before it finally became saturated with nutrients. The Sulphur denitrator is the first device I have come across that seems to have predictable, permanent, nitrate reducing capability. So I will probably continue with it, along with low level carbon dosing to help control phosphate.
Roy
Thanks for the pdf. great info. Nice perspective on holistic nutrient control.
That's a big tank. Glad to hear of your success. I have read many Carbon dosing success stories. I have been carbon dosing for some time (3 years) with limited results (vinegar / kalk top off water). It kept my phosphates very low, but nitrates still climbed. I have a remote DSB and that also doesn't seem to keep up with the nitrogen load. I have tried algal turf scrubbers, they were way more work and trouble than they were worth. The only passive nitrate control method I have had some success with was a DSB in my old main display tank that maintained near zero nitrates for about 10 years before it finally became saturated with nutrients. The Sulphur denitrator is the first device I have come across that seems to have predictable, permanent, nitrate reducing capability. So I will probably continue with it, along with low level carbon dosing to help control phosphate.
Roy
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rclendan
New member
Let's recap... All life is carbon based. We all agree that T. Denitrificans needs some form of carbon to survive right? Where does it get that carbon from?
If you get nothing else out of this exchange, please take away the fact that T. Denitrificans does not expel carbon dioxide, it consumes it. Qualitatively, it is a chemoautotroph, and can fix carbon from CO2 right out of the water and turn it into biomass. If it is truly an obligate autotroph, then it lacks the enzymes needed to break down organic material. Therefore, it can only consume CO2 as a carbon source, and my sucrose is facilitating some other mechanism of nitrate removal. But CO2 should still spur growth.
This is why this species has been investigated for use as a carbon sequestering sink by the fossil fuel industry.
That being said, oxidation of ammonia by Nitrosomonas and Nitrobacter into nitrate does expel some CO2, but this is of no consequence here.
Quantitatively, I want to get an idea of how much carbon is actually consumed.
Roy
If you get nothing else out of this exchange, please take away the fact that T. Denitrificans does not expel carbon dioxide, it consumes it. Qualitatively, it is a chemoautotroph, and can fix carbon from CO2 right out of the water and turn it into biomass. If it is truly an obligate autotroph, then it lacks the enzymes needed to break down organic material. Therefore, it can only consume CO2 as a carbon source, and my sucrose is facilitating some other mechanism of nitrate removal. But CO2 should still spur growth.
This is why this species has been investigated for use as a carbon sequestering sink by the fossil fuel industry.
That being said, oxidation of ammonia by Nitrosomonas and Nitrobacter into nitrate does expel some CO2, but this is of no consequence here.
Quantitatively, I want to get an idea of how much carbon is actually consumed.
Roy
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Roy .
Do you think the CHO3 used in the reaction might be more easily limited in a slow flow reactor than the CO2? Just thinking it through .
On another subject:
IME with organic carbon dosing(vodka and vinegar) it is very slow to reduce nitrates when they are high but does a good job of maintaining low NO3 < 1ppm to undectible as a maintenace dose . So, I haven't needed to use my sufur denitrator on this system since start up. I had planned to do so if I needed it. Tried deep sand beds and algae refguia nothing cut the NO3 liek the sulfur dentraor.
I suspect, the one step process by heterotrophic bacteria using ammonia for N limits NO3 production from ammonia oxidation enough to account for NO3 control but not a lot of NO3 reduction per se occurs from it at least not for months. These heterotrophs bacteria do seem to do a good job on inorganic phosphate too. I think many just dose up to reduce nitrates leading to overdosing and trouble in some cases. Any thoughts?
I'm interested in potential combinations and if they can be balanced
Do you think the CHO3 used in the reaction might be more easily limited in a slow flow reactor than the CO2? Just thinking it through .
On another subject:
IME with organic carbon dosing(vodka and vinegar) it is very slow to reduce nitrates when they are high but does a good job of maintaining low NO3 < 1ppm to undectible as a maintenace dose . So, I haven't needed to use my sufur denitrator on this system since start up. I had planned to do so if I needed it. Tried deep sand beds and algae refguia nothing cut the NO3 liek the sulfur dentraor.
I suspect, the one step process by heterotrophic bacteria using ammonia for N limits NO3 production from ammonia oxidation enough to account for NO3 control but not a lot of NO3 reduction per se occurs from it at least not for months. These heterotrophs bacteria do seem to do a good job on inorganic phosphate too. I think many just dose up to reduce nitrates leading to overdosing and trouble in some cases. Any thoughts?
I'm interested in potential combinations and if they can be balanced
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When in a sulfur-denitrator carbon is dosed it will become a carbon denitrator and the presence of T. nitrificans will be very limited if at all present. This is when the oxygen level is low enough for heterotrophe de-nitrification.
The first sentence might be true as the heterotrophs may out compete the sulfur bacteria but I don't think that's a certainty ;
the second sentence implies an anoxic condition is needed for the hetrotrophic bacteria to use nitrogen . They use free oxygen and like T nitrificans are facultative moving on to nitrate for it when free oxygen is exhausted. When there is no oxygen and no nitrate, sulfate reducing bacteria come into pay in the presence of organic carbon.
The first sentence might be true as the heterotrophs may out compete the sulfur bacteria but I don't think that's a certainty ;
the second sentence implies an anoxic condition is needed for the hetrotrophic bacteria to use nitrogen . They use free oxygen and like T nitrificans are facultative moving on to nitrate for it when free oxygen is exhausted. When there is no oxygen and no nitrate, sulfate reducing bacteria come into pay in the presence of organic carbon.
Belgian Anthias
New member
What does ATP/ ADP have to do with the CO2 question? They use CO2 in their biomass and ATP to move things around. All living things use some phosphate. ATP is not unique to T Nitificans .
The question Roy raised is about CO2 and/ or some potential mixotrophic orgnanic carbon consumption by T nitrificans in sulfur reactors not bacterial consumption of organic carbon in carbon reactors as I read it.
The question Roy raised is about CO2 and/ or some potential mixotrophic orgnanic carbon consumption by T nitrificans in sulfur reactors not bacterial consumption of organic carbon in carbon reactors as I read it.
CHSUB
"Certified Hobby Expert"
I have had almost the exact experience you have had. Vinegar dosing proved ineffective in controlling no3 to my satisfaction; however po4 remained undetectable even with a photometer. Sulfur proved to be the best answer to no3, imo. The one important aspect that Mr. Belgium has stressed, ad nauseam, and that I second is the size of the reactor being of importence. I believe the reactor should use at least 1% volume sulfur in relation to the DT. I found less don't allow enough processing of DT water. I will add that menthol denitrators are also very effective, having used one for several years in the early 2000's, however I believe sulfur is easier but slightly less effective.
Belgian Anthias
New member
The total consumption is an easy question to answer, if one has the means to measure it. How one will know how much is consumed by T.denitrificans is an other question. How one will know if T. denitrificans is responsible for the consumption if one can not be sure they are present and if they are, how much.
On one particle of sulfur there are a lot of different species of bacteria active and there quantities, proportions and intensity of activity will change constantly depending of the constantly changing micro-biotic circumstances.
If the reactor is carbon dosed I doubt there will be any T. denitrificans acive
Belgian Anthias
New member
Slad
Slad
It would be interesting to know the effect on the reactor of bringing in more CO2.
In SLAD wastewater systems the CO2 saturation is important.
In a SLAD process,the electron donor is elemental sulfur; the carbon source is CO2; and limestone provides alkalinity and inorganic carbon (Batchelor and Lawrence, 1978a, 1978b; Zhang, 2002).
In a sulfur-limestone autotrophic denitrification (SLAD) process, autotrophic denitrificans, such as Thiobacillus denitrificans and Thiomicrospira denitrifican, can oxidize a wide variety of reduced sulfur compounds (H2S, S, S2O32-, S4O62-, SO32-), while reducing nitrate or nitrite to elemental nitrogen (Baalsruud and Baalsruud, 1954; Bachelor and Lawrence,1978a, b, c; Claus and Kutzner, 1985b; Zhang, 2002).
Slad
It would be interesting to know the effect on the reactor of bringing in more CO2.
In SLAD wastewater systems the CO2 saturation is important.
In a SLAD process,the electron donor is elemental sulfur; the carbon source is CO2; and limestone provides alkalinity and inorganic carbon (Batchelor and Lawrence, 1978a, 1978b; Zhang, 2002).
In a sulfur-limestone autotrophic denitrification (SLAD) process, autotrophic denitrificans, such as Thiobacillus denitrificans and Thiomicrospira denitrifican, can oxidize a wide variety of reduced sulfur compounds (H2S, S, S2O32-, S4O62-, SO32-), while reducing nitrate or nitrite to elemental nitrogen (Baalsruud and Baalsruud, 1954; Bachelor and Lawrence,1978a, b, c; Claus and Kutzner, 1985b; Zhang, 2002).
Belgian Anthias
New member
That is true when reducing nitrate at elevated levels and relatively low daily production. This changes when a very low nitrate level has to be maintained by removing high daily nitrate production and high flow is needed to be able to remove the daily production. A sulfur denitrator will keep on functioning at oxygen saturation levels where a carbon denitrator will stop working. This only when the reactor is big enough. ( a 1% reactor will do in most cases) For example: to keep a nitrate level of 0.2ppm at a daily production of 0.5 ppm a reactor of at least 2% is needed. This is very difficult to accomplish with a carbon based reactor.
The effectiveness of a carbon denitrator depends completely of the daily dosed feeding. A sulfur denitrator does not need daily feeding which makes the system reliable and maintenance free.
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If the reactor is carbon dosed I doubt there will be any T. denitrificans acive
In post 1517 I leaned that way and sitll do to an extent.
I can't ignore the studies that Roy noted which suggest T nitrifcans may benefit to some degree from some level of organic carbon even though they are chemolithoauotrophic. Further both Roy and CHSUB are dosing organic carbon to their systems which include sulfur denitrators with reports of satisfactory nitrate reduction
.So, combinations may be possible and perhaps T nitrificans can avoid domination by the heterotrophs. I don't think so but don't really know that.
I'm not going to rehash the sizing issue again. . There are enough reports throughout this thread to suggest there is not a need for so much sulfur . It results in more alk depletion and sulfate addition than necessary.The amount of sulfur needed relates to the amount of nitrate not the overall water volume of the tank. On this matter we disagree. I do not need 13 gallons of sulfur on my 650 gallon aquarium . I used one gallonand documented the effort earlier on as did many others.
In post 1517 I leaned that way and sitll do to an extent.
I can't ignore the studies that Roy noted which suggest T nitrifcans may benefit to some degree from some level of organic carbon even though they are chemolithoauotrophic. Further both Roy and CHSUB are dosing organic carbon to their systems which include sulfur denitrators with reports of satisfactory nitrate reduction
.So, combinations may be possible and perhaps T nitrificans can avoid domination by the heterotrophs. I don't think so but don't really know that.
I'm not going to rehash the sizing issue again. . There are enough reports throughout this thread to suggest there is not a need for so much sulfur . It results in more alk depletion and sulfate addition than necessary.The amount of sulfur needed relates to the amount of nitrate not the overall water volume of the tank. On this matter we disagree. I do not need 13 gallons of sulfur on my 650 gallon aquarium . I used one gallonand documented the effort earlier on as did many others.
rclendan
New member
I will look into using CHO3 as a source.
Yes... I am sure a larger denitrator will process more water. That seems like a no-brainer. but my unit has only 0.5 gallons of sulphur for a 130 gallon total volume tank/sump/refugium and it still keeps my nitrates very low (below the MDL of my test kit)
Please link to the study on this. I am very interested.
Bacteria that are not carbon based? Are we talking Andromeda Strain here? Sulfur based life is hypothetical only (like silicon based life). Sulfur is able to form long-chain molecules, but it is typically too reactive like phosphorus and silanes. Plus, It only forms linear chains. To support life, it would need to make branching chains as well. Sulfur-reducing bacteria use elemental sulfur and nitrate instead of oxygen, reducing sulfur to hydrogen sulfide. they don't eat it. so much as they breath it.
Please see the paper below:
TRUDINOER, P. A. 1956. Fixation of carbon dioxide
by extracts of the strict autotroph Thiobacillus
denitrificans. Biochem. J. 64:274-286.
http://www.biochemj.org/bj/064/0274/0640274.pdf
The paper describes a lot of intermediate chemistry, but ultimately supports the fact that T. Denitrificans is capable of synthesizing hexose phosphates from carbon dioxide by a cyclic mechanism which is similar to that found in green plants.
_______________________________
Roy
https://www.flickr.com/photos/72828507@N07/sets/72157628943778043/
Yes... I am sure a larger denitrator will process more water. That seems like a no-brainer. but my unit has only 0.5 gallons of sulphur for a 130 gallon total volume tank/sump/refugium and it still keeps my nitrates very low (below the MDL of my test kit)
Please link to the study on this. I am very interested.
Bacteria that are not carbon based? Are we talking Andromeda Strain here? Sulfur based life is hypothetical only (like silicon based life). Sulfur is able to form long-chain molecules, but it is typically too reactive like phosphorus and silanes. Plus, It only forms linear chains. To support life, it would need to make branching chains as well. Sulfur-reducing bacteria use elemental sulfur and nitrate instead of oxygen, reducing sulfur to hydrogen sulfide. they don't eat it. so much as they breath it.
Please see the paper below:
TRUDINOER, P. A. 1956. Fixation of carbon dioxide
by extracts of the strict autotroph Thiobacillus
denitrificans. Biochem. J. 64:274-286.
http://www.biochemj.org/bj/064/0274/0640274.pdf
The paper describes a lot of intermediate chemistry, but ultimately supports the fact that T. Denitrificans is capable of synthesizing hexose phosphates from carbon dioxide by a cyclic mechanism which is similar to that found in green plants.
_______________________________
Roy
https://www.flickr.com/photos/72828507@N07/sets/72157628943778043/
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AZRippster
Diver & Reef Aquarium Nut
I'm definitely with you on this one Tom.
I have a 450 that I originally based the sulfur amount on the .006 per gallon calculation. Since I introduced it in late Nov '14, and since my nitrates hit hobby level testing values of 0, I have been reducing the amount of sulfur in my reactor. I figure, less food source, the less sulfur needed. Anyway, I have an AquaC RX-1 modded to be my reactor and it has been working wonderfully on my 450 mixed reef.
