DIY Sulfur Denitrator

[Belgian Anthias]

Do you think that a ORP controlled reactor will increase the flow in accordance with the nitrate level? Now the system contains 50ppm. How much the flow will be increased when 1ppm will be reached?

That is the million dollar question.

I agree, “The million dollar question”? Maximum vs. equilibrium, as I stated early imo, it’s closer to max. I did however take Mr. Belgium advice to task. When my dosing pump failed, I connected the reactor to my manifold and ran a constant flow and a higher ORP (-50 to 0) while testing the effluent. I found ORP above -100, -99,-98 etc. give a slight pink on a Salifert Tester, which imo is unacceptable. I would slow flow some, test until Salifert was clear (ORP~ -150) and try to increase flow again. I would, however, never get greater flow than I would with ORP controlling the pump. I also feel a test kit with greater accuracy would be needed to properly tune a reactor without ORP, as the NSW that I get from Halover Cut in Miami always shows clear on Salifert and I’m sure no3 is present. Imo, the reactor performs best from -150 to -190 ORP, which gives unreadable NO3 and good flow.

Why slight pink is unacceptable? For removing high nitrate levels we do not want 0 nitrate effluent. When more than the daily nitrate production is removed the level will decent . There will be some nitrite in the effluent, that is normal. As the effluent is aerated this will be oxidized fast to nitrate again.

My opinion, the reactor is always kept in his start up phase due to the ON-OFF . When the HRT in the reactor becomes to long nitrate and oxygen becomes very limited limiting the population. When the pump comes on again they must start again . In a start up phase nitrite is reduced to nitrogen gas only when most nitrate is reduced to nitrite. Only at the stage where the population has not enough with reducing nitrate to nitrite they will start to reduce nitrite to nitrogen gas. This process can be followed when starting up a sulphur denitrator. Imagine that when the population has become big enough there food is than limited. ( pump off) they will reduce the nitrite fast; Most of the population will die off, some part may even start to reduce sulphate. When the pump comes back ON they first start to reduce nitrate to nitrite again until the population is enough to start reducing nitrite again. The population never can find its balance.
We know that the start up takes always +- 12 day's, +- 8- 10 days are needed before nitrite will be reduced to N. It will be faster here because the population has not to start from 0. I hope! It is normal that nitrite is produced when the flow increases. The bacteria need time to adapt to the new situation and grow till they are able to consume the increased amount of oxygen and are able, or better must reduce NO2 to N ( 3 atoms O instead of one)
But while they grow they will be stopped growing because ORP will switch OFF the pump limiting there life sources.
I do think that a ORP controled reactor with an ON-OFF sequence fails back into start up sequence each time or at least most of the time which is a possible reason not being able to increase the flow to a normal level.

A reactor with a constant high flow ( reactor must be big enough) and a stabilized and very active population will react very fast on flow or nitrate production changes, Normally within 24 hrs the reactor will be stable again.

A sulphur denitrator will not work fine when there is very little production There must be a constant supply of nitrate to be able to keep very low stable nitrate levels. In systems with very little production all nitrate may be used up which means the reactor will fall back into start up mode. With less than 0.2ppm nitrate production daily it seems to be better to use an other nitrate removal method if necessary at all or a small sulphur denitrator managed the way a carbon based reactor can be managed. The system will be limited to reduce a bit of nitrate but controlling the nitrate level in the systemwill not be possible.

 

[Belgian Anthias]

Dennis

To have the nitrate under control You need to know the daily nitrate production in the system.
Than you can estimate if your system will be able to reduce the nitrate level to the level you desire.
What you call a million dollar question is a question that should have been answered before investing in an expensive system that may not be able to do what it is intended for. Removing 50 ppm to 1ppm is not easy when there is a lot op production and it will need more than dripping rate to keep it at a low level. Again it is important to know the daily production. When this is known you will become very rich because the million dollar question can be answered easily.
To remove 0.5 ppm daily at a nitrate level of 1ppm a flow of +- 2.5 gal/h is needed ( 120 gal system) when the effluent is kept at 0 nitrate.
How long does the seeding pump turns at 900 gal/h to charge the reactor ?
How long ON and how long OFF?

 

[CHSUB]

To have the nitrate under control You need to know the daily nitrate production in the system.
Than you can estimate if your system will be able to reduce the nitrate level to the level you desire.
What you call a million dollar question is a question that should have been answered before investing in an expensive system that may not be able to do what it is intended for. Removing 50 ppm to 1ppm is not easy when there is a lot op production and it will need more than dripping rate to keep it at a low level. Again it is important to know the daily production. When this is known you will become very rich because the million dollar question can be answered easily.
To remove 0.5 ppm daily at a nitrate level of 1ppm a flow of +- 2.5 gal/h is needed ( 120 gal system) when the effluent is kept at 0 nitrate.
How long does the seeding pump turns at 900 gal/h to charge the reactor ?
How long ON and how long OFF?

why not find 20 day nitrate production and remove that every 20 days?

 

[dartier]

How long does the seeding pump turns at 900 gal/h to charge the reactor ?How long ON and how long OFF?

That was in an earlier post of mine (2:43 seconds ON, 6:00 minutes OFF), however that is all water under the bridge.

I discovered that my circulation pump was too strong, or adjusted too strong, and had ground up some of the sulfur prills due to excessive boiling action at the bottom outlet of my PVC down tube. When I removed my ORP probe to seal it better, a deluge of milky yellow water drained from my reactor into my test barrel. Guess I am going to need that flow dispersion plate sooner rather than later.

Tonight I am just creating the tool path to cut a lower and upper flow plate, and I plan to cut it later this week. Then I will be draining and rinsing the sulfur dust from my test barrel, and restart testing with an eye to keeping a lower flow and having the sulfur prills somewhat contained, with the flow more evenly spread out.

Part of the issue is the depth of my test barrel makes it difficult to observe what is taking place in the reactor. But having this learning experience take place safely disconnected from the tank is the important thing.

Dennis

 

[dartier]

Here is what I intend to cut out of acrylic. There will be a bottom one and a top one. The centre hole size and diameter of the plate itself are approximate until I disassemble the filter, measure the actual components, and adjust the program to fit. I will probably use 3mm acrylic for it (depending what I have on hand).

Hopefully this will help to diffuse the circulation flow and prevent the sulfur from getting too agitated and ground up in the future.

Dennis

 

[tmz]

I think there are several related variables in play at the same time:

flow in terms of on/off cycles controlled by ORP to keep the water void of free oxygen but not anoxic ,i.e. free of oxygen bound to nitrogen.

activity by facultative sulfur bacteria,

and

the activity of facultative heterotrophic bacteria encouraged by the carbon dosing in the two ORP controlled systems under discussion( both of which include organic carbon dosing to the aquariums IIRC) .

To be clear: I think the combination of organic carbon dosing and sulfur might be useful for nitrate reductiuon in combination with sulfur with ORP control but I don't think we know that since the heterotrophic bacteria may dominate the sulfur landscape when organic carbon is readily available to them.

So,it seems to me we have a "who done it ? "; where at least some if not most or all of the nitrate reduction occurring at low ORP managed by the flow off functions may be the result of activity by the heterotrophic bacteria feeding on organic carbon vs sulfur. Do the sulfur bacteria and the heterotrophic bacteria act as a team in nitrate reduction or is one likely to dominate the other? How would ORP control work in a system without enriched levels of organic carbon?

 

[CHSUB]

I think there are several related variables in play at the same time:

flow in terms of on/off cycles controlled by ORP to keep the water void of free oxygen but not anoxic ,i.e. free of oxygen bound to nitrogen.

activity by facultative sulfur bacteria,

and

the activity of facultative heterotrophic bacteria encouraged by the carbon dosing in the two ORP controlled systems under discussion( both of which include organic carbon dosing to the aquariums IIRC) .

To be clear: I think the combination of organic carbon dosing and sulfur might be useful for nitrate reductiuon in combination with sulfur with ORP control but I don't think we know that since the heterotrophic bacteria may dominate the sulfur landscape when organic carbon is readily available to them.

So,it seems to me we have a "who done it ? "; where at least some if not most or all of the nitrate reduction occurring at low ORP managed by the flow off functions may be the result of activity by the heterotrophic bacteria feeding on organic carbon vs sulfur. Do the sulfur bacteria and the heterotrophic bacteria act as a team in nitrate reduction or is one likely to dominate the other? How would ORP control work in a system without enriched levels of organic carbon?

my system was using organic carbon dosing in combination with a sulfur reactor, however, i stopped dosing about 8 months ago. changes in my system did occur: the most surprising was no3 went lower from ~10 ppm to <1.00 ppm with no other changes. i did add more fish and an autofeeded with 4 a day feedings after no3 level went lower, but i'm still maintaining low no3. the sulfur reactor does processes more water with longer on times(ORP controlled) post carbon dosing, but that can be explained by a lower no3 input level. a guess would be that my system was po4 limited by carbon dosing and a macro fug. Currently, po4 @ .009 and no3 @ <1.00 and sps' growth, color is excellent.

imo, sulfur bacteria require lower ORP than bacteria using organic carbon dosing. years ago i used a methanol reactor and no3 reduction was excellent, however ORP never went negative. Using sulfur, best results are seen with ORP at ~-170.

 

[tmz]

Sounds good . Thanks for the update.

 

[Belgian Anthias]

Do you think that a ORP controlled reactor will increase the flow in accordance with the nitrate level?

YIKES!!!!!!!!!!!∞

that is what is does....higher NO3 longer off time, lower NO3 shorter off time. this has been discussed over and over......

I think we are speaking about different things. I am speaking about the nitrate level in the aquarium system not of the nitrate level in the reactor.

 

[Belgian Anthias]

why not find 20 day nitrate production and remove that every 20 days?

To keep the nitrate level steady at the level which is desired one must remove the nitrate production before it can accumulate. When the total system volume can pass the reactor only once every 20 days this means the nitrate level entering the reactor must be very high or the daily production very low. To keep the nitrate level steady at 0.5ppm at a normal daily production of 0.5ppm one must pas the total volume of the aquarium system once a day true the reactor, efluent 0 nitrate, To do the same with only 0.1ppm in the system water flow must increase by factor 5. It is as simple as that. On can not remove what is not entered.
A sulfur reactor works fine at any daily flow but only when the reactor is big enough and the bacteria have a constant supply of food to stay healthy and active.
A good designed sulfur denitrator is based on its oxygen consuming capacity which allows high flow.

 

[Belgian Anthias]

Here is what I intend to cut out of acrylic. There will be a bottom one and a top one. The centre hole size and diameter of the plate itself are approximate until I disassemble the filter, measure the actual components, and adjust the program to fit. I will probably use 3mm acrylic for it (depending what I have on hand).

Hopefully this will help to diffuse the circulation flow and prevent the sulfur from getting too agitated and ground up in the future.

Dennis

Just plumbing the pump in with a closed loop and a regulating valve will give full control of the pump outflow without restricting the pump.

 

[Belgian Anthias]

That was in an earlier post of mine (2:43 seconds ON, 6:00 minutes OFF), however that is all water under the bridge.

I discovered that my circulation pump was too strong, or adjusted too strong, and had ground up some of the sulfur prills due to excessive boiling action at the bottom outlet of my PVC down tube. When I removed my ORP probe to seal it better, a deluge of milky yellow water drained from my reactor into my test barrel. Guess I am going to need that flow dispersion plate sooner rather than later.

Tonight I am just creating the tool path to cut a lower and upper flow plate, and I plan to cut it later this week. Then I will be draining and rinsing the sulfur dust from my test barrel, and restart testing with an eye to keeping a lower flow and having the sulfur prills somewhat contained, with the flow more evenly spread out.

Part of the issue is the depth of my test barrel makes it difficult to observe what is taking place in the reactor. But having this learning experience take place safely disconnected from the tank is the important thing.

Dennis

Pumps must be in a closed loop for easy flow management.
As the reactor is disconnected find out the daily production. Measure the nitrate level now and at the same time next week. When the production to remove is known we can estimate the volume of the reactor needed. If you are going to continue using the ORP controlled ON - OFF system I can not help you. I know how to manage sulfur based denitrator systems. We call them BADESS

 

[dartier]

Well I finally got my flow plates cut and started my reactor back up tonight. It took me longer than expected since gremlins had visited the wiring of my CNC, and it became intermittent. I was planning on re-wiring it as soon as I received a bootlace crimper I had on order anyway (it arrived a few weeks back). Now I have a nicely crimped wiring harness with colour coded ferrules

Here is how they turned out. What did not work so well, or how to do it better next time, after the photos ...

What would I do differently? Well I would not cut slots, or I would cut them using a cutter smaller than the 1/8" one I used. The sulfur prills can slide through the slots when they are on edge, Doh! I ended up putting a needle point disc on the top and bottom plate to prevent the prills from escaping. I could have drilled a sea of holes, but thought slots would be quicker. Quicker yes, but the holes would have contained the prills :headwally:

I also dispensed with the bags of Matrix that I had sitting on top of the sulfur media. The bags had collected a lot of yellow mulm.

Dennis

 

[canada55]

Had three 6"x18" up flow reactors sitting around doing nothing so I thought I would build up one of these Sulfur reactors ... 500gal system, Nitrates around 75ppm. Doing 100gal water changes didn't seem to help so I thought I would give it a go..

 

[canada55]

Sorry forgot picture..

 

[Belgian Anthias]

Had three 6"x18" up flow reactors sitting around doing nothing so I thought I would build up one of these Sulfur reactors ... 500gal system, Nitrates around 75ppm. Doing 100gal water changes didn't seem to help so I thought I would give it a go..

Nice build. How many sulphur in volume is used ( +-2Gal, 7.5lit?)? What is the media in the GEO reactors? What is the media on top of the sulfhur and why is it put there? Direction of flow? From the sulphur reactor to grey GEO than to yellow GEO?
What nitrate level is desired? How long did it take for the nitrate level to build up to 75ppm? Any idea of the daily nitrate production?
As the reactors are full I suppose the media is not moved around?
For a 500 gal system not enough sulphur is used to bring the level to <2ppm. ( depends of the daily production of nitrate to remove)
When a reactor effluent of 0 nitrate is desired, to be able to increase the flow as necessary, 2% sulphur is normally used to reduce 75ppm to +- 1 ppm and keep it there. ( all depending of the daily nitrate production to remove)
To start up the reactor with a nitrate content this high the reactor should be separated from the system and connected to a separate container ( bucket?) containing system water. This way the start up process can be followed easily and when the reactor is cured it can be connected to the system.

 

[canada55]

I went with the formula 500g X .006 = 3ltr sulfur, but since I'm high on my nitrates I went the full gallon (3.75ltr), I can always easily remove or add sulfur at any time.

1 gal sulfur, 8 ltr of Matrix, 2 gal or ARM.

Flow enters bottom of left reactor (sulfur) out the top and then enters bottom of second reactor (Matrix) reactor the then finally out the top and the enters the bottom of third reactor full of ARM. The output of the ARM reactor has two(2) outputs lines and then followed by my input feed. The circ pump a Ehiem compact + marine is a variable flow pump.

My first reactor has ORP probe controller Mil. SMS125. With two(2) outputs lines I can have one with a manually controlled drip/flow, the second output I have a NC pinch valve, when ORP reaches higher than -180 the controller energizes the pinch valve and opens increasing flow through reactors. Once ORP returns to optimal range pinch valve closes.

The first reactor is sulfur and I gently placed some matrix on top the sulfur to fill the space and to keep sulfur from fluidizing. The blue stuff is matala mat they use in koi ponds.

Yes, I am running the reactor off a separate system of display water. Being experimental, I wanted to play and fiddle with this for a month of more before connecting up to the larger live system.

It's now been 5 days since I started it up, nitrates are still high 75ppm - 100ppm, PH has drop down to 7.3, ORP is at 145. Just today I started to see small gas bubbles forming on inside of in the clear reactor tops. I am daily venting tops but none to very little gas.

My intention, once connect to main system is to drip reactor output into a 6" round PVC pipe with an airstone in bottom and filled with ARM to help (hopefully) raise PH. If that don't work I'll set up a kalk reactor to raise PH. Sure hope this works..lol

 

[Belgian Anthias]

I went with the formula 500g X .006 = 3ltr sulfur, but since I'm high on my nitrates I went the full gallon (3.75ltr), I can always easily remove or add sulfur at any time.

1 gal sulfur, 8 ltr of Matrix, 2 gal or ARM.

Flow enters bottom of left reactor (sulfur) out the top and then enters bottom of second reactor (Matrix) reactor the then finally out the top and the enters the bottom of third reactor full of ARM. The output of the ARM reactor has two(2) outputs lines and then followed by my input feed. The circ pump a Ehiem compact + marine is a variable flow pump.

My first reactor has ORP probe controller Mil. SMS125. With two(2) outputs lines I can have one with a manually controlled drip/flow, the second output I have a NC pinch valve, when ORP reaches higher than -180 the controller energizes the pinch valve and opens increasing flow through reactors. Once ORP returns to optimal range pinch valve closes.

The first reactor is sulfur and I gently placed some matrix on top the sulfur to fill the space and to keep sulfur from fluidizing. The blue stuff is matala mat they use in koi ponds.

Yes, I am running the reactor off a separate system of display water. Being experimental, I wanted to play and fiddle with this for a month of more before connecting up to the larger live system.

It's now been 5 days since I started it up, nitrates are still high 75ppm - 100ppm, PH has drop down to 7.3, ORP is at 145. Just today I started to see small gas bubbles forming on inside of in the clear reactor tops. I am daily venting tops but none to very little gas.

My intention, once connect to main system is to drip reactor output into a 6" round PVC pipe with an airstone in bottom and filled with ARM to help (hopefully) raise PH. If that don't work I'll set up a kalk reactor to raise PH. Sure hope this works..lol

What is the function of the matrix in a sulphur dentrator? And why is it placed after tbe sulphur?75 or 100 ppm makes a big difference! Correct info is important. To reduce the nitrate level more than the daily nitrate production has to be removed daily. Will this reactor be able to remove the daily production? As the reactor is ORP controled flow will be limited. At this high levels this should not be a problem but how the flow will follow the nitrate level to be able to remove the production at the disered nitrate level? Normally it takes less than 2 weeks to cure a sulfur reactor but as the flow is interrupted by ORP and the available food (nitrate) and oxygen changes all the time it may be possible the reactor will never find its balance. The start up process can be monitored by the nitrite level in the water. Normally nitrite increases during 8 to 10 days and than decents very fast . At that stage nitrogen gas production will start. This at a constant regular flow.
As the reactor is not a moving bed reactor the flow interruptions by ORP control may increase the risk for channeling and annoxic zones considerably . ORP reading will be that from the water that passes the probe, not from the the water that may stagnate in sulfur.
In a sulfur denitrator the amount of free oxygen should be regulated by the amount of bacteria that uses it up and have the ability to switch over oxydising sulfur and not by limiting the supply. One can only remove what passes through the reactor!

 

[canada55]

"What is the function of the matrix in a sulphur dentrator?"

cut and paste from
Do It Yourself "“ Sulfur Reactor
By Frank Aguilar (djfrankie)

"For those with really large aquarium systems I recommend you use Seachem's Matrix (not the carbon) in addition to the sulfur as this seems to work quite well in providing lots of space for the colonizing bacteria. I have used as much as 1.5 liters of Seachem's Matrix per liter of sulfur with great results."

You come across as very knowledgeable about the subject, but you ask a lot of dumb *** question. There are no rules to this experimental reactor. Everyone system is so different, you can't apply what works with absolute certainty.

 

[CHSUB]

I went with the formula 500g X .006 = 3ltr sulfur, but since I'm high on my nitrates I went the full gallon (3.75ltr), I can always easily remove or add sulfur at any time.

1 gal sulfur, 8 ltr of Matrix, 2 gal or ARM.

Flow enters bottom of left reactor (sulfur) out the top and then enters bottom of second reactor (Matrix) reactor the then finally out the top and the enters the bottom of third reactor full of ARM. The output of the ARM reactor has two(2) outputs lines and then followed by my input feed. The circ pump a Ehiem compact + marine is a variable flow pump.

My first reactor has ORP probe controller Mil. SMS125. With two(2) outputs lines I can have one with a manually controlled drip/flow, the second output I have a NC pinch valve, when ORP reaches higher than -180 the controller energizes the pinch valve and opens increasing flow through reactors. Once ORP returns to optimal range pinch valve closes.

The first reactor is sulfur and I gently placed some matrix on top the sulfur to fill the space and to keep sulfur from fluidizing. The blue stuff is matala mat they use in koi ponds.

Yes, I am running the reactor off a separate system of display water. Being experimental, I wanted to play and fiddle with this for a month of more before connecting up to the larger live system.

It's now been 5 days since I started it up, nitrates are still high 75ppm - 100ppm, PH has drop down to 7.3, ORP is at 145. Just today I started to see small gas bubbles forming on inside of in the clear reactor tops. I am daily venting tops but none to very little gas.

My intention, once connect to main system is to drip reactor output into a 6" round PVC pipe with an airstone in bottom and filled with ARM to help (hopefully) raise PH. If that don't work I'll set up a kalk reactor to raise PH. Sure hope this works..lol

interesting set-up!!! what chamber are you monitoring pH? i have read that pH above 7.0 is better for the sulfur bacteria? keep us posted on the progress. given the size of the system, i would have filled two reactors with sulfur and monitored the second chamber, but only time will tell? Deltec's system is similar with orp controlling a second flow into the reactor. GL