Sulphur in the reefaquarium

[Belgian Anthias]

A nitrifying biofilm will not function properly without elemental sulfur being produced and reused. HS is produced constantly and used by autotrophic denitrification everywhere in the aquarium. Elemental sulfur production and consumption is an essential part of the normal sulfur cycle and the nitrogen cycle. Using produced elemental sulfur is the basic process of BADES. Elemental sulfur production and consumption takes place in all aerobic remineralization filters.

Adding some elemental sulfur to the substrate for growing a nitrifying biofilm will increase the natural nitrate export rate already present. No need for a deep sand bed promoting anaerobic remineralization and sulfate reduction.

 

[Randy Holmes-Farley Verified Community Expert]

A nitrifying biofilm will not function properly without elemental sulfur being produced and reused. HS is produced constantly and used by autotrophic denitrification everywhere in the aquarium. Elemental sulfur production and consumption is an essential part of the normal sulfur cycle and the nitrogen cycle. Using produced elemental sulfur is the basic process of BADES. Elemental sulfur production and consumption takes place in all aerobic remineralization filters.

Adding some elemental sulfur to the substrate for growing a nitrifying biofilm will increase the natural nitrate export rate already present. No need for a deep sand bed promoting anaerobic remineralization and sulfate reduction

elemental sulfur is not any part of aerobic nitrification

 

[Belgian Anthias]

elemental sulfur is not any part of aerobic nitrification

Nobody said it is. There is aerobic mineralization and anaerobic mineralization both taking place in a nitrifying biofilm, nitrification is always aerobic, Nitrate being an end product of natural aerobic remineralization.

 

[Belgian Anthias]

Elemental sulfur is an essential part of de sulfur and nitrogen cycles within the nitrifying biofilm.

+- 40% of active live part of a normal nitrifying biofilm use an anaerobic pathway. Autotrophic denitrification is essential for maintaining HS below toxic levels within the oxygen transition zones of the biofilm. Oxidizing HS using nitrate , HS constantly produced by anaerobic mineralization, sulfate and or elemental sulfur is produced. If HS availability is low, produced elemental sulfur is used to maintain the population sulfur bacteria as T.denitrificans anaerobic active , see BADES. ( biological anaerobic denitrification with elemental sulfur).

Adding some elemental sulfur to the substrate of a plenum will have a huge influence on the nitrate removal rate. ( Longouet 1999) See also Delbeek and Sprung V3 p 283

Jaubert installed some big plenum aquaria in the MONACO aquarium.
Elemental sulfur production is a normal side product of anaerobic HS oxidation using nitrate. In normal circumstances ( a balanced biofilm) most produced sulfur is reused.
Using a plenum it is the intention to create an oxygen transition zone, limiting sulfate reduction and HS production.

Creating anoxic conditions ( below 0.5 ppm O) should be avoided. Using a deep sandbed one has no control (bio-fooling, clogging) , the nitrogen removal rate is not manageable. One does not need a deep sand bed to export nitrate.

 

[Randy Holmes-Farley Verified Community Expert]

I do not see a reason to be debating obscure aspects of the sulfur cycle. I do not think it likely that nelyrag had a very rare system that produced elemental sulfur in his sand, but obviously I cannot prove what it was from a description of being yellow.

I'll note that many marine bacteria are yellow:

https://www.sciencedirect.com/science/article/pii/S1074552115002884

 

[Belgian Anthias]

I do not see a reason to be debating obscure aspects of the sulfur cycle. I do not think it likely that nelyrag had a very rare system that produced elemental sulfur in his sand, but obviously I cannot prove what it was from a description of being yellow.

I'll note that many marine bacteria are yellow:

https://www.sciencedirect.com/science/article/pii/S1074552115002884

What is the obscure aspect ? Sulfur production and consumption is a common normal and essential natural process taking place everywhere anaerobic mineralization takes place. The BADES proces is one of the natural pathways exporting nitrogen.

Marine Sulfur bacteria may store a huge amount of sulfur turning the sea bottom yellow.

Conclusion. the yellow also may be elemental sulfur. Not difficult to find out.

 

[Belgian Anthias]

Sulfur and sulfur compounds are indispensable in the life processes. Notwithstanding the large amount of sulfur and sulfur compounds naturally occurring in seawater, most closed seawater aquarium systems are deficient in usable suitable sulfur. Providing elemental sulfur is usually sufficient to close the nitrogen cycle. No need for filters or reactors. just add some on the bottom of your sump. Nature will do the rest.

 

[Randy Holmes-Farley Verified Community Expert]

Accumulating elemental sulfur is obscure and not at all necessary or expected. It is mostly associated with hydrothermal vents although there are some obscure settings where it may biologically accumulate.

IMO, it is not something reefers need to add to their chemical understanding of their aquaria.

 

[Belgian Anthias]

Accumulating elemental sulfur is obscure and not at all necessary or expected. It is mostly associated with hydrothermal vents although there are some obscure settings where it may biologically accumulate.

I looked it up in Webster and I think the word obscure is not used in the correct context.
Referring to the obscure setting of accumulation of millions tons of biological elemental sulfur before the coasts of South America .

I was talking about a normal and essential process oxidizing HS exporting nitrogen taking place in all marine aquariums; It is in the interest of reefers knowing how nitrogen is exported. Knowing one may expect some elemental sulfur may accumulate in deep sand beds, when using the Jaubert method or denitrators, this when a lot of HS is produced, although it is not common or expected. But in the case it is necessary.

Adding some elemental sulfur for most reefers struggling with nitrogen export it will be a simple solution for a small problem.

 

[Randy Holmes-Farley Verified Community Expert]

Yes, obscure is the exact word I intended.

" not clear or plain; ambiguous, vague, or uncertain:"

You are just wildly speculating that elemental sulfur is playing any role in normal reef aquaria. There's no evidence of any processes involving accumulating elemental sulfur in reef aquaria.

And except for people adding elemental sulfur in a sulfur denitrator, it plays no demonstrated role in the nitrogen cycle in a reef tank. Hence, it's role (if any at all) is " ambiguous, vague, or uncertain".

Hydrogen sulfide, H2S (not HS), on the other hand, is absolutely important to understand as it very well can play a role in many scenerios in low O2 settings.

 

[Belgian Anthias]

Yes, obscure is the exact word I intended.

" not clear or plain; ambiguous, vague, or uncertain:"

You are just wildly speculating that elemental sulfur is playing any role in normal reef aquaria. There's no evidence of any processes involving accumulating elemental sulfur in reef aquaria.

And except for people adding elemental sulfur in a sulfur denitrator, it plays no demonstrated role in the nitrogen cycle in a reef tank. Hence, it's role (if any at all) is " ambiguous, vague, or uncertain".

Hydrogen sulfide, H2S (not HS), on the other hand, is absolutely important to understand as it very well can play a role in many scenerios in low O2 settings.

How one may understand the role of H2S in the denitrification process and nitrogen cycle without talking about complete and partial sulfide oxidation and complete sulfide oxidation? It does take place in normal aquarium conditions.
At pH 8.2 +- 95% of produced H2S is HS.


Elemental sulfur is produced constantly in reef aquaria oxidizing H2S using nitrate! Why it is NOT possible it may accumulate?


Maybe the evidence is ignored when claiming the yellow may not be elemental sulfur? We do know elemental sulfur is produced.

If someone is speculating it is not me! I am convinced because I do know it is a normal and essential natural process. The information is available. I do know adding some elemental sulfur does make a difference.

 

[Belgian Anthias]

It has been demonstrated H2S production and sulfide oxidation using nitrate takes place in normal marine nitrifying biofilms. No need for special low O2 settings although the nitrogen removal rate can be managed using a reactor and managing the flow. ( BADES biofilm reactor)
Natural oxygen consumption of remineralisation and nitrification processes create an environment for anaerobic activities. +- 40% of bio activity is anaerobic. Adding some elemental sulfur will support the autotrophic denitrification capacity. see BADES rolls.


Elemental sulfur is produced in a normal biofilm, the possibility exists it accumulates,

However limited or extensive elemental sulfur production is, it is constantly produced and plays an important role in the nitrogen cycle as it is essential for maintaining a population of autotrophic denitrifiers responsible for nitrogen export. It has been shown that in marine nitrifying biofilters the autotrophic nitrogen export exceeds the heterotrophic nitrogen export in many cases depending on the prevailing conditions.
With addition of elemental sulfur, a bigger population of autotrophic denitrifiers is maintained, including a higher autotrophic denitrification capacity.



I suggest that one just try it, a thin layer of elemental sulfur mixed with a calcareous substrate at the bottom of the sump.( 1 cm is enough, max 2 cm) It for certain will not harm a thing.

 

[Randy Holmes-Farley Verified Community Expert]

Im not going to continue to argue with random assertions. I have read extensively in chemical oceanography textbooks and articles about sulfur processes and see no reason to think that accumulating elemental sulfur is produced in any reef aquarium. Might I be wrong? Maybe. But I think I am more likely to be correct.

In my hydrogen sulfide and ORP articles I discuss all of the processes that I think are significant in a reef tank involving sulfur species, and these were taken from a variety of expert textbooks that discuss all of these processes.

 

[Randy Holmes-Farley Verified Community Expert]

Hydrogen Sulfide and the Reef Aquarium by Randy Holmes-Farley - Reefkeeping.com

 

[Randy Holmes-Farley Verified Community Expert]

You mentioned it would be “not difficult” to determine if the yellow stuff was sulfur or not. What did you have in mind?

One way is to burn it outside and look for a blue flame. It would need to be washed free of seawater first.

 

[Belgian Anthias]

Im not going to continue to argue with random assertions. I have read extensively in chemical oceanography textbooks and articles about sulfur processes and see no reason to think that accumulating elemental sulfur is produced in any reef aquarium. Might I be wrong? Maybe. But I think I am more likely to be correct.

In my hydrogen sulfide and ORP articles I discuss all of the processes that I think are significant in a reef tank involving sulfur species, and these were taken from a variety of expert textbooks that discuss all of these processes.

What is significant for reefers is not someones decision. Natural processes are what they are.

 

[Randy Holmes-Farley Verified Community Expert]

What is significant for reefers is not someones decision. Natural processes are what they are.

Well, there’s far more chemistry taking place in reef tanks than any reef hobbyists know.

That does not mean they need to understand every minor process taking place to have a wonderful reef tank.

 

[Belgian Anthias]

it are the minor but essential things which keep the major things going and for this reason they are the most important of all. Not having attention for the minor things makes proper troubleshooting of major problems impossible.

The oxidation of H2S using nitrate, is a minor process which a reefer may not ignore. It is responsible for the majority of natural nitrogen export, closing the sulfate cycle transforming H2S in S and finally back to sulfate. The total natural denitrification capacity of a normal nitrifying biofilm is autotrophic + heterotrophic , is not minor but significant, has been shown to be +- 16% of in the biofilm produced nitrate. A lot of produced H2S is first anaerobically reduced to S, exporting nitrogen gas, before to be transformed anaerobically back to sulfate, also exporting nitrogen gas. This process is called BADES and can be used for managing the nitrogen export rate as desired by the user.

In marine aquaria most anaerobic remineralization taking place in anoxic conditions uses sulfate, producing H2S due to the fact very little or no nitrate becomes available in anoxic zones created in a reef aquarium, zones with limited water and oxygen exhange. In biofilms most nitrate penetrating the sub layers is used up in oxygen transition zones, mainly for respiration , the oxidation of H2S produced constantly by natural anaerobic remineralization.

Considering natural anaerobic remineralization and denitrification are cataloged as minor processes they are of great importance to maintain and manage a closed marine life support system.

The formation of sulfur may be minor but essential and accumulation of sulfur is possible, certainly in deep sand beds there where organic material is accumulating. The yellow stuff may be sulfur loaded bacteria or and elemental sulfur.

 

[Randy Holmes-Farley Verified Community Expert]

The oxidation of H2S using nitrate, is a minor process which a reefer may not ignore. It is responsible for the majority of natural nitrogen export, closing the sulfate cycle transforming H2S in S and finally back to sulfate.

IMO, that is a wild and baseless claim.

you really think there is so much hydrogen sulfide present that it dominates nitrate export over processes such as denitrification involving oxidation of organics?

This is from one of my articles, describing the process:

In the absence of O2, and taking the nitrogen species completely to N2 (which may happen in several reaction steps), we have the following overall reaction:

organic + 124 NO3– + 124 H+ → 122 CO2 + 70 N2 + 208 H2O

You believe that reactions involving hydrogen sulfide dominate over that one?

 

[Belgian Anthias]

IMO, that is a wild and baseless claim.

you really think there is so much hydrogen sulfide present that it dominates nitrate export over processes such as denitrification involving oxidation of organics?

This is from one of my articles, describing the process:

In the absence of O2, and taking the nitrogen species completely to N2 (which may happen in several reaction steps), we have the following overall reaction:

organic + 124 NO3– + 124 H+ → 122 CO2 + 70 N2 + 208 H2O

You believe that reactions involving hydrogen sulfide dominate over that one?

I am claiming nothing, just explaining how things work, based on approved information, available for consultation.

The process you talk about takes place only in anoxic conditions.( <0.5 ppm O) In a normal nitrifying biofilm most nitrate is exported in the oxygen transition zones. The formula you use is about anaerobic remineralization of organics, using nitrate as an oxygen source. When no nitrate is available manganese, iron and sulfate is used, In a marine aquarium sulfate is always available.

In a healthy and balanced nitrifying biofilm little nitrate becomes available in anoxic zones because it is used up in the transition zones for oxidizing H2S produced by anaerobic remineralization. Sulfur Bacteria following an anaerobic pathway are active in oxygen transition zones, and are able to switch between an aerobic pathway and an anaerobic pathway, using up available oxygen oxidizing sulfur compounds aerobically, using up nitrate oxidizing H2S and produced S anaerobically, creating conditions suitable for anaerobic remineralization, a minor but essential process in a nitrifying biofilm. This way nature closes the cycles. if more nitrate is used up in transition zones, less nitrate becomes available for anaerobic remineralization producing more H2S. If more H2S is produced more nitrate is used to oxidize it and less nitrate will become available for heterotrophic denitrification. An equilibrium may be established in relation to the available nitrate. Hereby again emphasizing the importance of nitrate production.

OM + 59H2SO4 → 106CO2 + 16NH3 + H3PO4 + 59H2S + 62H2O. Ammonia is produced providing the nitrogen source for new autotrophic growth in the oxygen transition zones. You do believe heterotrophic denitrification is dominant over that one?


The same takes place in the aquarium in places with very little water exchange, oxygen is consumed, first nitrate and sulfate are used for anaerobic remineralisation of organics. Some H2S is produced and is oxidized using nitrate present in the oxygen transition zones. Less nitrate becomes available for anaerobic remineralisation, more sulfate is reduced and more ammonia becomes available for maintaining growth, autotrophic growth needed to oxidize produced H2S, producing sulfur. Nature keeps all processes going. This in normal conditions.

There is no reason to believe that anaerobic remineralization using nitrate is a dominant process for exporting nitrate in normal aquarium conditions. It has been shown in normal aquarium conditions a biofilm exports +- 16 % of in the biofilm produced nitrate. It has been shown adding some elemental sulfur does increase the natural nitrogen export rate. ( it may reach +80% using BADES rolls at a supply of 100 mg/l NH4-N per day ) this in normal aquarium conditions.

Your opinion the natural nitrogen export is mainly based on heterotrophic denitrification?
Is it what reefers must believe? No elemental sulfur is produced in a marine aquarium because it is a minor process without any importance for reefers?