Anaerobic Bacteria Cultivation

[ChrisCummins]

Hi,

For a coil de-nitrator I'm working on, I'll need to know what factors affect the growth and health of anaerobic bacteria. Things I'm interested in include:

1) Flow - I've heard about 3-5 lph works best?
2) Light - does light levels affect it? Should it be blacked out?
3) Temp
4) Location - where they mostly gather. i.e. on bio-balls or on sides of tube etc

Another thing to take into account is the equilibrium between the amount of anearobic bacter either:

a) Turning the de-nitrator into a nitrate farm

OR

b) Turning the de-nitrator into a toxic gas farm

Apreciate any help.

Thanks,
Chris

PS: the answer to the above question will hopefully also bring the answer to how long should the airline tubing coil be before it goes into the bio-balls chamber.

 

[Monkey_Bone]

Flow shoud be LOW ( have to give it a chance to work), Light is an issue as well so black it out ( the best denitrification takes place in the absence of light), Temp is an issue also dont let it get above say 80-82 deg. F. same as your tank. coil up about 20 feet of tubing before the bioballs and that should be plenty.
your biggest foe is going to be the bioballs not the denitrator.
Biobals are typicly nitrate factories by themselves.

 

[ChrisCummins]

Thanks alot for the info Monkey Bone!

With the ball valves, flow at such low levels is quite low to adjust, but about 6 drops a second seems to be about 2 lph or so.

I went looking for some parts for something else for my reef and happen to stumble accross a 71 part "Drip Irrigation" set. One of the parts was a 23mtr (about 70ft or so) roll of 6mm vinyl tubing, so I bought it and have wrapped it around the de-nitrator chamber. The tubing is black so blacks out the light getting to the bio-balls as well.

I'm thinking that with so much airline, all the O2 will have been starved before it gets to the bio-balls anyway so aerobic nitrification will be out of the equation. The thing I'm still unsure about is hydrogen sulphide production. Anyone know more about it?

Thanks,
Chris

 

[ChrisCummins]

Using the Winogradsky column example, I can make a pretty accurate guess at what going to happen in the various stages of the project.

1) The Coil 1-10m - non-photosynthetic aerobic bacteria colonise and produce NH3, NH4, NO2, NO3 (nitrification) etc.
2) The Coil 11-23m - non-photosynthetic aerobic bacteria strip water of O2 and create anaerobic zone, with nitrate reducing (de-nitrification), sulphur reducing, ammonium producing (dissimilatory ammonium production I think).
3) Anaerobic chamber - non-photosynthetic totally anaerobic bacter oxidise sulphates into hydrogen sulphide.
4) H2S rich, O2 stripped water is dumped back into tank.

The last section reveals the flaw in the de-nitrator principle, as it shows that theoretically you're just creating an aquarium toxicifier, not de-nitrator.

The bacteria which caught my eye were the photosynthertic anaerobic green and purple suplhur reducing bacteria, which convert hydrogen sulphide and carbon dioxide into water, hydrogen suplhide and glucose:

6CO2 + 12H2S = C6H12O6 + 6O2 + 12S

So, to encourage the growth of hydrogen sulphide reducing bacteria I would need another, lit chamber?

Thanks,
Chris

 

[Bryan89]

Chris,

I use a sulphur denitrification system consisting of sulphur beads. I reduced nitrates in my tank from 120 ppm to 2 ppm in 4 weeks while cycling my tank. Two weeks later my nitrates were zero and never rose again. My reactor is not blacked out and empties directly into my sump at a flow rate of about 1 gallon US per hour. I use a needle valve on the effluent to contol the flow rate.

HTH

Bryan

 

[Monkey_Bone]

Chriss, thats not totaly true.
FLOW determins how much 02 is stripped as well as all other contaminents.
You can determin how much of any thing is filtered simply by flow in a denitrator.