DIY Sulfur Denitrator

[Belgian Anthias]

From SO4 to H2S

From SO4 to H2S

I don't think your denitrification bacteria have died (I do stand to be corrected though). Nitrate is always present in a system, but it is used up as quickly as it is generated. If the drop killed off all the dentrifyers that would apply to DSB's, Zeovit etc as well and you would have to start-stop-start-stop-start using these as your nitrates went up and down.
The rotten egg smell is caused by the conversion of Sulfate (SO4--) to H2S. As the nitrates are too low the bacteria then use the Sulfate as an oxygen source.

If you ramp up your flow a bit you introduce more Nitrates that they can use. To counter the H2S you can run your effluent through Granular Ferric Oxide (GFO) which converts the H2S back into S. If your flow is too high, the unit will produce Nitrites as the Nitrate isn't given chance to break down completely.
That is why your effluent should preferrably be directed back over the compartment of the Skimmer and LR. Nitrites will be converted back into Nitrates and the Skimmer will aerate the oxygen poor effluent.
Another simple way is to simply increase yor bio load a you now have to "feed" your reactor.
It is very importnat to remember that a Sulfur Denitrifyer is not a fire-and-forget item but has to be constantly monitored. That is probably why they haven't been as widely used as other nitrate reducers.

Can you explain me how de-nitrifacation bacteria form H2S From SO4? I do not understand.
At my opinion H2S can not be formed from the reaction with the sulfer. It is a mistake to think that the H2S comes from the Sulfur. H2S is formed when your bacteria die and as they have a unlimited food sorce ( the sulfur) they can only die when there is to much oxygen, to much flow.
It is true that the bacteria use the oxygen from the sulfur, that is why the sulfur is there for. So there is S left. As far everything is normal.
The system will create nitrite only during start up or when it is clogged. That is why we use fluidizised bed reactors, to prevent the possebility of clogging.
So, at my opinion, your way of thinking is wrong.
It is normal procedure to aerate the enfluent to get the gasses out. The small amount of sulfite that is formed will also be driven out here. The fact that you can smell it is the prove that it is driven out, is it not? So, it is not dangerous. It is an advantage that you can smell it when something is wrong, so you can do something about it.
Nitrification is done by bacteria, not by air only.
I use it for a long time and had never problems with it but you have to follow the rule of max flow.
I have a small flow meter afther the calcium reactors and if you use fludizised bed reactors the system needs no more atention than other equipment. Using sulfur controles nitrate and eliminates the use of a special CO² calcium reactor. When the system is automated it can regulate your PH also. I change 1/3 of the sulfur every year.
Even when you stop using it and you keep the reactor closed you can easily re-use it afther a month at max capacity because the bacteria stay alive feeding on the sulfur. We did the test. So, they do not need nitrate to survive.

 

[Belgian Anthias]

Why

Why

Well it's a diy of my own design. It probaly had to high flow going threw it. So I claned it all up and now there is only a quarter of the media in there. I'm running it wide open for 24 hours then I will back it down to a drip per second just like I started. I just hope that a MJ1200 isn't too much now that I don't have it full

Why do you run it open for 24h?
You can put a closed loop on your pump and a controlable valve for easy flow controle.

 

[speedo2wet]

Output of effluent

Output of effluent

Djfrankie: I waswondering becuase earlier on you stated that you tried to run the effluent out of the top and it was getting clogged. What was it getting clogged with? I was wondering if it were to come out of the top degass valve then there would have to be more pressure in the chamber - right?

What if the out put was placed higher than you have it now, closer to the top through the flange on the side. Do you think this would be able to pull the effluent and the gas out of the system with out having to degass the system every day. I'm just wondering since (do to job) I'm not always home every day. It would be at the highest point possible and little room to build up gasses.

Let me know.

Hey also, if it would not work, have you ever seen or heard of a low adjustable pressure degassing valve that we could use on top. I am unable to find something of that sort.

I have a 250 gallon system and only about 22 inches of height under my tank. More of a sitting room than anything so it works. Also I will be dealing with sting rays and sharks and well they are a dirty and nitrate production factory so this would be a great thing to run. Plus I would not have to do that pocket emptying water changes. LOL

 

[Belgian Anthias]

. they can only die when there is to much oxygen, to much flow.
It is true that the bacteria use the oxygen from the sulfur, that is why the sulfur is there for. So there is S left. As far everything is normal.
The system will create nitrite only during start up or when it is clogged. That is why we use fluidizised bed reactors, to prevent the possebility of clogging.
So, at my opinion, your way of thinking is wrong.

I have to correct my self here and I do excuse myself.
Folowing the original tekst of Marc Longouet:

Il est à noter que si l'on augmente trop vite le débit par rapport au taux de nitrate et au volume de soufre on peut voir des nitrites et des nitrates réapparaître en sortie de réacteur suite à une réaction incomplète. Par contre il est rare de produire des sulfures (caractérisés par une odeur proche des œufs pourris) ; ceci ne se produit que dans le cas de débit excessivement faible dans le réacteur (à la limite de l'arrêt, par exemple par colmatage) ou dans le cas de chemins préférentiels conduisant à la non irrigation d'une partie du réacteur et à la réalisation d'un milieu anoxique (c'est à dire privé totalement d'oxygène) ; la production de sulfures est sans conséquence dans la mesure où ils sont toujours liés à un débit très faible et donc que leur quantité négligeable est réoxydée en sulfate dans le bac.

Leur présence est d'autant plus rare que Thiobacillus denitrificans en condition anaérobie est elle-même capable d'oxyder les sulfures en sulfate au même titre que le soufre. En revanche lors d'un décolmatage on ne laisse pas le temps aux bactéries de faire cette transformation et des sulfures peuvent sortir en faible quantité du réacteur.

I was wrong
It is not true that nitrite is formed when the filter is cloged. It is Sulfite that can be formed due to compleet abcence of oxygen and the presence of bioload. (dead bacteria?)
When the flow is to high and the Thiobacillus denitrificans are still alive there will be nitrite in the enfluent because the bacteria have not the time to compleet the cycle. At start up there will be nitrite because there are not enough bacteria to compleet the cycle. I hope I have it right now.
A fluidizised bed can normally not clog, so where did the sulfite came from.
Wat condition caused forming sulfite? Or was de reactor overfilled so that the media clogged? Or was there a period of time no enfluent at all?

 

[Corry]

Can you explain me how de-nitrifacation bacteria form H2S From SO4? I do not understand.
At my opinion H2S can not be formed from the reaction with the sulfer. It is a mistake to think that the H2S comes from the Sulfur. H2S is formed when your bacteria die and as they have a unlimited food sorce ( the sulfur) they can only die when there is to much oxygen, to much flow.
It is true that the bacteria use the oxygen from the sulfur, that is why the sulfur is there for. So there is S left. As far everything is normal.
The system will create nitrite only during start up or when it is clogged. That is why we use fluidizised bed reactors, to prevent the possebility of clogging.
So, at my opinion, your way of thinking is wrong.
It is normal procedure to aerate the enfluent to get the gasses out. The small amount of sulfite that is formed will also be driven out here. The fact that you can smell it is the prove that it is driven out, is it not? So, it is not dangerous. It is an advantage that you can smell it when something is wrong, so you can do something about it.
Nitrification is done by bacteria, not by air only.
I use it for a long time and had never problems with it but you have to follow the rule of max flow.
I have a small flow meter afther the calcium reactors and if you use fludizised bed reactors the system needs no more atention than other equipment. Using sulfur controles nitrate and eliminates the use of a special CO² calcium reactor. When the system is automated it can regulate your PH also. I change 1/3 of the sulfur every year.
Even when you stop using it and you keep the reactor closed you can easily re-use it afther a month at max capacity because the bacteria stay alive feeding on the sulfur. We did the test. So, they do not need nitrate to survive.

Firstly, understand the process of how the Sulfur DN works. Anaerobic bacteria colonise the sulfur and use it and NO3 as a food source. Although Anearobic, i.e. in the abscence of O2, the bacteria obtain their oxygen by reducing NO3 to N2 and using the "released" O2. Sulfate (SO4) is a by-product of this metabolisation. However, when the flow through the unit is too slow or NO3 levels too low, the bacteria then use the SO4 as an oxygen source. Remember the level of SO4 in sea water is like 8000ppm so we aren't worried about the SO4 produced by the unit. The reduction of SO4 leads to the production of H2S.
THe H2S can be made safe by letting the effluent flow through GFO (Granular ferric Oxide) which will yield Sulfur again as an end product.
THe full mechanism of this reaction is explained by Davidov et al. (Mechanism of H2S Oxidation by Ferric Oxide and Hydroxide Surfaces, J. Phys. Chem. B, 1998, 102 (24), pp 4745-4752)

 

[Belgian Anthias]

Gfo

Gfo

Firstly, understand the process of how the Sulfur DN works. Anaerobic bacteria colonise the sulfur and use it and NO3 as a food source. Although Anearobic, i.e. in the abscence of O2, the bacteria obtain their oxygen by reducing NO3 to N2 and using the "released" O2. Sulfate (SO4) is a by-product of this metabolisation. However, when the flow through the unit is too slow or NO3 levels too low, the bacteria then use the SO4 as an oxygen source. Remember the level of SO4 in sea water is like 8000ppm so we aren't worried about the SO4 produced by the unit. The reduction of SO4 leads to the production of H2S.
THe H2S can be made safe by letting the effluent flow through GFO (Granular ferric Oxide) which will yield Sulfur again as an end product.
THe full mechanism of this reaction is explained by Davidov et al. (Mechanism of H2S Oxidation by Ferric Oxide and Hydroxide Surfaces, J. Phys. Chem. B, 1998, 102 (24), pp 4745-4752)

I never used GFO because I had never real problems with Sulfite. When sulfite is formed there is only a small amount. I believe that when the enfluent is goed aereated sulfite will not cause problems.


11 S + 10 NO3- + 4.1 HCO3- + 0.5 CO2 + 1.71 NH4+ + 2.5 H2O ---> 0.92 C5H7NO2 +
11 SO4-- + 5.4 N2 + 9.62 H+

This should be the normal de-nitrification process when sulfur is used.
From expierience I know that when I slow down the enfluent( normally I use 5x the volume of sulfer, wich is a high enfluent) the enfluent becomes more accid. I use this fact to regulate my calcium. I stop at 1x the volume and had never problems.
From expierience I know also that when you close the reactor ond you leave the water in it, there will be sulfite after a few days when you open it.
When I empty the reactor (only the water out) and keep it closed I can re-use the reactor without problems. The bacteria stay alive, so they do not need oxygen to survive ?
When the water stays in the reactor, there is a little bit of SO4 in the water but this can not be enough to produce that amount of Sulfite. So my theorie is that the sulfite must come from dead bacteria and not from the sulfur or SO4
Which reactions would turn SO4 into H2S? Afther all oxygen is used there must be other bacteria whom will decompose the dead bacteria and form the sulfite? I am not a chemist! So I try to understand my way.

 

[denverhoss]

Interesting stuff. One question that I didn't see talked about is why this needs to be a recirculating reactor. Can it be done as a single pass and save the electrical use and extra maintenance? At least I didn't find it on the search I did.

Thanks!

 

[herpboyben]

Has anyone here built one of these using 3 inch pvc? if so what did you use as a diffuser plate at the bottom? thanks
Ben

 

[dahenley]

is there a plastic shower drain, or look in the irrigation section, and find one of those drain filters. (shower ones are SS or plastic, get the plastic, the irrigation ones are green. you can look in to those.)

 

[Belgian Anthias]

recirculating ore not?

recirculating ore not?

Interesting stuff. One question that I didn't see talked about is why this needs to be a recirculating reactor. Can it be done as a single pass and save the electrical use and extra maintenance? At least I didn't find it on the search I did.

Thanks!

I use a fluidizised bed to prevent that the media can clog together and clog the reactor. It prevents the possebility of producing H2S. In a normal tube it is possible that the sulfur clogges together and the water may make it self a raceway thrue the media. In that case the reactor will not work and you will not notice it because there may be normal flow. I think you will measure Nitrite in the enfluent in that case.
You do not need a recirculating reactor, it can easely be done by a normal tube,single pass, but recirculating reactors give more security and easy constant flow control.

 

[Belgian Anthias]

SO4 and calcium reactors

SO4 and calcium reactors

My opinion and experience.




Question 4) Nothing will neutralize the SO4 ( sulfate) and you don't want to. It's a natural and large part of sea water.. There is 2700ppm in sea water and your mixed water, so anything you would use to remove S04 would harm your water overall. Because there is so much sulfate in the water already ,the effect of the additions from the reactor should not upset the overall water chemistry ratios significantly.
The problem is with sulfide from hydrogen sulfide formation which may occur when the reactor is running too slow or when a 0 nitrate condition otherwise exists, since the bacteria in this case can't strip the 0 from nitrate N03, they turn to sulfate for oxygen (S04) and produce hydrogen sulfide , which is toxic. It is thought the sulfide may be reduced to relatively harmless elemental sulfur by an interaction with granulated ferric oxide (gfo). So passing the effluent through gfo is prudent in my opinion.

The argonite will to some degree raise the ph of the effluent as it dissolves. It will also proivude a small amunt of alkalinity and calcium to the tank.

Some people believe that the SO4 stayes in the calcium reactors and will be removed when the calcium is changed. Hignette, conservator of Paris aquaria claimed this :

Michel HIGNETTE conservateur de l'aquarium du Musée des Arts Africains et Océaniens à Paris a constaté lors d'études récentes que les sulfates étaient piégés par les colonnes de calcaire destinées à tamponner l'acidité de l'eau et que le taux de sulfate sur un bac en fonctionnement dans les conditions préconisées restait donc pratiquement stable sur une longue période. Le substrat calcaire, qui petit à petit se réduit en boue par attaque acide, devant être remplacé après un certain temps d'utilisation (malgré tout assez long), les sulfates produits se trouvent ainsi éliminés.

If other calcium media are used in the reactors as aragonite, for example maerl, cocollits or a commercial "Calcite" , calcium can become too high (till 800)
Ph, calcium and alkalinity can be controled using different media and regulating the flow( higher or lower accid effluent to the calcium reactors).

 

[retroblew]

Okay newbie question. I got the sulfur from midwest aquatic and the the arm from premium aquatics. I am following the DIY from djFrankie, and I am a little confused at how much sulphur to put along with the arm. my water volume is 140 gallons and by the calculations is .84 litres, how many pounds do I put of sulfur with the arm. What has worked for everyone? Ideas...thanks in advance!!!

 

[Belgian Anthias]

sulfur quantity.

sulfur quantity.

Okay newbie question. I got the sulfur from midwest aquatic and the the arm from premium aquatics. I am following the DIY from djFrankie, and I am a little confused at how much sulphur to put along with the arm. my water volume is 140 gallons and by the calculations is .84 litres, how many pounds do I put of sulfur with the arm. What has worked for everyone? Ideas...thanks in advance!!!

Using .84 l of sulfur means that your normal effluent flow will be between +-1lit/h and +-4.2lit/h. This is not easy to regulate. I would use 1% of the tank volume sulfur, in this case 1.4 gal sulfur witch gives me a controlable flow of +- 7 gal/h max

 

[saltydog64]

Okay newbie question. I got the sulfur from midwest aquatic and the the arm from premium aquatics. I am following the DIY from djFrankie, and I am a little confused at how much sulphur to put along with the arm. my water volume is 140 gallons and by the calculations is .84 litres, how many pounds do I put of sulfur with the arm. What has worked for everyone? Ideas...thanks in advance!!!

First....Welcome to RC.

I've been with this thread from it's very start, but because of my summer job I haven't posted in a while :mad2::mad2:. AND everytime I tried to deviate from dJ's original setup I had nothing but trouble, why do I start with this, simply, to many here recently are trying to do just that...if they what to use a different approach good BUT start your own thread...

I recently restarted my SR (sulfur reactor) last week and it initially cycled to zero nitrate in 3 days ( @ that time my system, 90 gal, tested @ +80 PPM).The flow rate (FR) was approx. 1drop/2sec (1d/2s).At the start the effluent was dumped into a 5Gal bucket (@ that FR you get about a 2000cc in there).I do this as Nitrite can be produced, just to be safe. This is slightly slower than suggested :rollface: I then increased FR to 1d/s got to zero the next day,then to 2d/s got to zero PPM and now FR is 5d/sec with lots of gas @ vent valve (VV). The nitates this am are @ 20 PPM so it continues to cycle. The SR is now hooked to the tank thru the Refugium tank, then into main tank (this has cheato in it with a bare bottom).I

What's in SR....about 1/3 gal of LSM (rinse this good with RO several times to remove the fines) and all the Matrix I could get in there. The first sponge is on the bottom then the sulfur, then the Matrix and finally the last sponge (make sure the sponges fit tight to the ID as the media will try to "float up". I filled this tank water, then with the top off, I turned on the mj1200 to let it circulate for 10 mins or so, while doing this gently tap the sides of the SR and you will amassed at the trapped air that will you see. I then put the top on and filled the SR with top VV opened until I saw water flow out the top. This assures the SR is full with little or no air @ the top. It's a good idea to place your unit in a 5 gal bucket just in case there's a leak you might have missed. At this time start your FR, orginally suggested @ 1d/s, I think this was for tanks with Nitrate @ less than 50 PPM ( I was using 1d/2s as my NO3 was @ +80 PPM.

I think dJ and others who have been here and have gotten excellant results will agree that a smaller amount of sulfur (less than the 1% of tank volume) will work as long as you have lots of media for the bacteria to colonize in and go slow to cycle it. I never got sigificant pH help from ARM so in my setup I'm not using any, but I could start one as I have 2nd unit ready to go.

As I said this how I'm running my SR ... a few url's to look at:

http://www.midwestaquatic.com/PRODUCTS/NBC_9.htm

http://www.marinedepot.com/CaribSea...Filter_Media-CaribSea-CS0528-FIFMCHSM-vi.html

http://www.marinedepot.com/Seachem_..._Filter_Media-Seachem-SC3171-FIFMBOCR-vi.html.

and I hope it helps.

 

[vegaskid11]

Using .84 l of sulfur means that your normal effluent flow will be between +-1lit/h and +-4.2lit/h. This is not easy to regulate. I would use 1% of the tank volume sulfur, in this case 1.4 gal sulfur witch gives me a controlable flow of +- 7 gal/h max

With this amount, I would have to use 5 gallons of sulfur for my 500 gallon system. Is that really neccesary?

I thought people were using much less sulfur.

I ordered a coralife calcium reactor for my SD and it arrives any day. I was just getting ready to order the sulfur from marine depot and was wondering a couple of things.

1. I was just gonna get a gallon of sulfur but now im not sure considering the above post.

2. Is using a media like seachem matrix below the sulfur still a good idea?

3. Has anyone using a coralife calcium reactor tapped a hole for a de-gass valve or would the effluent carry the gas off sufficiently.


Thanks

 

[retroblew]

Salty, thanks for the welcome. I have already bought the small package from midwest aquatic and the Larger arm from premium aquatics. In this case for 140 gallons of water, do you recommend putting half or 3/4 of the sulfur in the reactor. Afterwards sponge, then matrix, then ARM. I am kind of worried about ph and alk going krazy. I dose calcium and buffer every 3 days already. Hopefully that was not too confusing

 

[saltydog64]

Salty, thanks for the welcome. I have already bought the small package from midwest aquatic and the Larger arm from premium aquatics. In this case for 140 gallons of water, do you recommend putting half or 3/4 of the sulfur in the reactor. Afterwards sponge, then matrix, then ARM. I am kind of worried about ph and alk going krazy. I dose calcium and buffer every 3 days already. Hopefully that was not too confusing

Good having u here !!!

The amount of S u brought should do nicely...You didn't mention your tank Nitrate @ this time ???

I can only pass on what I have tried and what works for me....but I think most use more Sulfur than what is actually needed. How much should use...if your Nitrates are less than 50PPM try 1/2...if quite high...3/4 of the gallon. You can store the rest for a future restart, when I feel u will need less. Keep in mine these are just first hand thoughts from MY tank....make sure to rinse the S several times in RO to remove as much fines as possible.

I would put a sponge in first (on the bottom), then the sulfur, put the matrix next and if you got room put in the ARM, then the final sponge....

No matter how hard u try, believe me pH and Alk will be a concern....it's the nature of the beast...Denitrification will lead to lower pH out of SR....NO matter what u do...I've checked mine with lab grade digital pH meter and even after coming out of 2nd reactor filled with only ARM and pH was never higher than 7.2 or 7.4...Out of the single SR it was and is between 6.68 and 7.01. So u see not much we can do.... EXCEPT....get your Nitrates under control, do your water changes and restart the SR when needed..

I have yet to hear from dJ himself..........but we all owe him a HUGE THANK YOU:hammer::hammer: for this great project....thx dJ.....

Good luck and remember the dJ SR works period.....

 

[retroblew]

I tried last night and the bloody thing was leaking...thanks for the bucket hint...I drained most of the water out and left the sulfur and arm in there. Hope i did not mess anything up. It was late and I get my PMS moment when sleepy so rushed and re applyed the cleaner and contact cement. I put a piece of clothe on top of the arm as where I was applying the glue was at the effluent end. I hope nothing got in the ARM. I plan to rinse it again and try again. BTW my nitrates are arround 40 ppms. Thank you Saltydog for all your wisdom...Hopefully you can teach this young dawg some new tricks!

 

[retroblew]

I forgot to ask...Is degassing every day necessary. I am out of town for 3 or 4 days at a time and was wondering about that. Can I just leave it open all the time. What is everyones take on that. AND indeed a big thanks to DJ for all the research and work for us to follow.

 

[Belgian Anthias]

Ph

Ph

Good having u here !!!

The amount of S u brought should do nicely...You didn't mention your tank Nitrate @ this time ???

I can only pass on what I have tried and what works for me....but I think most use more Sulfur than what is actually needed. How much should use...if your Nitrates are less than 50PPM try 1/2...if quite high...3/4 of the gallon. You can store the rest for a future restart, when I feel u will need less. Keep in mine these are just first hand thoughts from MY tank....make sure to rinse the S several times in RO to remove as much fines as possible.

I would put a sponge in first (on the bottom), then the sulfur, put the matrix next and if you got room put in the ARM, then the final sponge....

No matter how hard u try, believe me pH and Alk will be a concern....it's the nature of the beast...Denitrification will lead to lower pH out of SR....NO matter what u do...I've checked mine with lab grade digital pH meter and even after coming out of 2nd reactor filled with only ARM and pH was never higher than 7.2 or 7.4...Out of the single SR it was and is between 6.68 and 7.01. So u see not much we can do.... EXCEPT....get your Nitrates under control, do your water changes and restart the SR when needed..

I have yet to hear from dJ himself..........but we all owe him a HUGE THANK YOU:hammer::hammer: for this great project....thx dJ.....

Good luck and remember the dJ SR works period.....

Maybe using an other calcium media ore/ and more will solve the problem? Aragonite is a form of calcium that is more stable than calcite, it don't disolve as easy as calcite.
The French pioneers and investigators of DN with sulfur systems used "maerl" as calcium sorce ( +- 32% CaCo3 and 3,1%MgCo3 Wikipedia) and dit not report much problems with Ph. They advise 1% sulfur and minimum the same volume of calcium media better 2x. This would bind the produced SO4 also.
Using 1% sulfur gives the possebility to play with the effluent to regulate the amount of H+ depending of the amount of Nitrate. This way calcium and PH can be corrected. Nitrate controlled. The smaller the system volume the more difficult it is to regulate.
When using aragonite only I would advice to use 1% sulfur so the effluent can easely be regulated to 1x the volume of sulfur because there is need for a more accid effluent to disolve the aragonite. The less sulfur used, the more difficult regulating the effluent. Sulfur is not expensive.
The main factor of the amount of sulfur is the bio-load of the system. The DN must be sufficient to ellimenate the bioload every day added (skimmer?), plus the Nitrate cumulated in the system. Once the DN eliminated the amount cummulated you can and must bring it down to a stable amount that is controlable by you. So the effluent flow must be increased? Here I am also limited bij the amount of Sulfur otherwise I will create nitrite?
Depending of the efficiency of the skimmer used, less than 1% suflur is needed but makes it more difficult to control all parameters as I can conclude of the above.
To have a stable running DN System I think it is better to keep +- 2 -5 ppm Nitrate in the system instead of going for O Nitrate.