my rice experiment

[DJREEF]

DJ are you sure that it's an efficient export mechanism? All you're exporting is whatever bio-slime is on the rice. Plus, with the ramp-up time involved, what happens to the N/P levels within the tank as the new rice is developing the bacterial culture?

I would say, given the rapid colonization of rice grains (people have reported them sliming up in a matter of days) that the NO3 pop would be negligible. Remember that growing bacterial colonies use vastly more energy and resources than static mature colonies. It's the PO4 from impurities introduced to the rice used for replacement that I think would be the main concern in this case. If this was addressed I don't think we'd have an issue at all.

DJ

 

[tmz]

DJ, If NO3 is negligible why are some rice users seeing it rise?

Du, In my opinion. The differences with vodka and vinegar are that you can control exactly how much organic carbon you dose at a given time and dose 0 nitrogen and other things; just pure ethanol or acetic acid.. Pellets don't contain N or P either as far as I know and may give a more localized digestion and release as well.

 

[Du]

DJ, If NO3 is negligible why are some rice users seeing it rise?

Du, In my opinion. The differences with vodka and vinegar are that you can control exactly how much organic carbon you dose at a given time and dose 0 nitrogen and other things; just pure ethanol or acetic acid.. Pellets don't contain N or P either as far as I know and may give a more localized digestion and release as well.

Yes, but with vodka you have a "busy hands". With solid carbon yours hand is free. Thats your time!

And what we have in rice. We have (in 100g) a 40 gramm of pure carbon and 100 mg of N and P. What ration of CNP we have?

 

[elijaher]

Still VSV is a hit and miss dosing side effect is not good.

 

[DJREEF]

It sounds like H2S( hydrogen sulfide gas ) formed as the rice decayed in stagnant water.The stench was likely H2S ,commonly called sewer gas and the black deposits are likely metal sulfides which occur as the H2S oxidizes. H2S is toxic to living things inlcuding you, as it is neutral (ie caries no negative or positive charge) and readily passes through cell membranes.

Here's how it happens. Faculative heterotrophic bacteria colonize the rice .

As heterotrophs they can not produce organic carbon ,as autotrophs can via photosynthesis, which is why we dose it to culture them.
Faculative means they respire free oxygen during the nitrification process ( ammonia > nitrite > nitrate. When the free oxygen is used up , as in a hypoxic area they respire the oxygen from NO3.
When the NO3( nitrate )is gone,the water is anoxic( no oxygen and no nitrate) . At this point sulfate(SO4) reducing bacteria will start taking the oxygen from SO4. Seawater and your tank water contains about 2.700ppm of sulfate. The sulfate reduction results in several by products including H2S( hydrogen sulfide) which is the one to be concerned about. The H2s diffuses throughout the water . As it hits oxic areas some of it combines with metals leaving sulfite deposits( probably the black stuff in your sump). It also forms elemental sulfur and some sulfite and sulfate.H2s will last a few a hours to a day before it is completely oxidized. The process can be quickened with some gfo as the iron can catalyze the oxidation process.

In other words - don't turn your return pump back on.

You've got some work to do scrubbing your equipment and sump out. Oh, and wear rubber gloves when you do this.


DJ

 

[philbo32]

I would have thought that as the levels of PO4 and NO3 are reduced you could reduce the amount of rice in accordance until a balance is found between rice,NO3 & PO4. I don't think that all the rice should be replaced at anyone time. Like with zeovit, you should probably leave at least 10% of old rice in the reactor to seed the new rice with heterotrophic bacteria.

@DJREEF, I agree rapid colonisation of bacteria on the new rice should have beneficial effects. Including removal of organics from any of the old rice left in the reactor (ca.10%) even if it was to cycle and end up as nitrate.

Don't forget a number of heterotrophic denitrifying bacteria work in an aerobic environment not just anaerobic. IMO these are the more beneficial bacteria in these sort of systems, not sulfide producing.

Having saprophitic bacteria in your system trying to digest a slow release carbon source will have the added benefit of releasing large amounts of hydrolytic enzymes into your system which will digest any left over organics and clear your water. These types of bacteria will also produce acidic products to try to digest the carbon source which may effect on the pH and have a reductive effect on the water.

 

[philbo32]

In other words - don't turn your return pump back on.

You've got some work to do scrubbing your equipment and sump out. Oh, and wear rubber gloves when you do this.


DJ

I would definitely siphon the stinky water away and rinse your rice with some clean seawater.

 

[DJREEF]

DJ, If NO3 is negligible why are some rice users seeing it rise?

Du, In my opinion. The differences with vodka and vinegar are that you can control exactly how much organic carbon you dose at a given time and dose 0 nitrogen and other things; just pure ethanol or acetic acid.. Pellets don't contain N or P either as far as I know and may give a more localized digestion and release as well.

My suspicion is the industry additives. Notice that the NO3 pops within the first few days from untreated rice then settles down to acceptable levels. Something is coating the surface of the grains that needs to be worked off. That's where adequate treatment before introduction comes in (ie properly soaking off the residue).

DJ

 

[philbo32]

my suspicion is the industry additives. Notice that the no3 pops within the first few days from untreated rice then settles down to acceptable levels. Something is coating the surface of the grains that needs to be worked off. That's where adequate treatment before introduction comes in (ie properly soaking off the residue).

Dj

+1

 

[philbo32]

As Cliff said earlier, a triple rinse over 3 days with RO water replacing RO water every 24 hours is probably the safest way to prime your rice ready for the reactor.

 

[tmz]

Don't forget a number of heterotrophic denitrifying bacteria work in an aerobic environment not just anaerobic. IMO these are the more beneficial bacteria in these sort of systems, not sulfide producing.


Not sure of your meaning.

I would agree faculative heterotrophic bacteria work in aerobic and anaerobic environments by definition as nitrifying/denitrifying bacteria do. Some may take N directly as a food source in the aerobic area as well but the more common use of the term denitrifying bacteria refers to anaerobic respiration of NO3 and N2 formation. Not sure at all which is the more important or dominant activity aerobic or anaerobic as it relates to NO3 reduction since I don't think there is any data available on this.Certainly the respiratory aerobic activity produces nitrate.
None of them reduce sulfate since this function is performed by obligate(with rare exceptions) anaerobic prokaryotes.

 

[thebanker]

Yes, but with vodka you have a "busy hands". With solid carbon yours hand is free. Thats your time!

Du, it is true that with the vodka you have "busy hands" but trust me i'd rather dose vodka daily than have to crack open my Phosban reactor every two weeks to change rice. Not to mention rinsing and soaking the rice in RODI. For reference, I'm using IONNR* now as solid vodka, and I only need to dose once a week. It takes less than a minute. I was dosing vodka previous to that, and it only took 15 seconds out of my day. It's not that difficult. In fact with vodka, the toughest part is figuring out what amount is needed to balance C with consumtion of N/P.

*instant ocean natural nitrate reducer = emulsified PCL biopellet


DJ - you may be right about the exportation of nutrients via the bacterial biomass. And yet again I revert to my first point... anyone with a fluidized reactor knows how much of a pain it can be to get in there and change out the media. I'd rather trim chaeto.

As Cliff said earlier, a triple rinse over 3 days with RO water replacing RO water every 24 hours is probably the safest way to prime your rice ready for the reactor.

Thats so much work. Does anyone else see it this way?

 

[DJREEF]

Du, it is true that with the vodka you have "busy hands" but trust me i'd rather dose vodka daily than have to crack open my Phosban reactor every two weeks to change rice. Not to mention rinsing and soaking the rice in RODI. For reference, I'm using IONNR* now as solid vodka, and I only need to dose once a week. It takes less than a minute. I was dosing vodka previous to that, and it only took 15 seconds out of my day. It's not that difficult. In fact with vodka, the toughest part is figuring out what amount is needed to balance C with consumtion of N/P.

*instant ocean natural nitrate reducer = emulsified PCL biopellet


DJ - you may be right about the exportation of nutrients via the bacterial biomass. And yet again I revert to my first point... anyone with a fluidized reactor knows how much of a pain it can be to get in there and change out the media. I'd rather trim chaeto.

I think my point is that the rice is going to eventually foul anyway, so it's going need replacing. My point is that if you change it before you get to that point you may be able to make the changing of the 'media' a beneficial process. It wouldn't be any different than changing carbon, or phosphate media monthly.

Imagine what it must be like for folks using the "rice in a bag method". Pulling a bag full of mush out without making a mess would be a trick.

As far as trimming Chaeto, hell, I'd do both if it netted results economically.

DJ

 

[philbo32]

the term denitrifying bacteria refers to anaerobic respiration of NO3 and N2 formation. Not sure at all which is the more important or dominant activity aerobic or anaerobic as it relates to NO3 reduction since I don't think there is any data available on this.Certainly the respiratory aerobic activity produces nitrate.

Heres some paper on aerobic denitrifying bacteria in the marine environment, they produce nitric oxide instead of nitrogen during the breakdown of nitrate; NO3 - NO2 - N2O

They are difficult to isolate and therefore in the past were relatively unknown, now with new techniques more and more aerobic denitrifiers in freshwater and marine environments are being found.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC161530/pdf/2103.pdf

http://aem.asm.org/cgi/content/full/67/4/1893

http://en.cnki.com.cn/Article_en/CJFDTOTAL-FJKS200908006.htm

There has been a lot of research and interest in these bacteria by waste treatment plant in recent years in freshwater.

To quote from this paper; http://www.nature.com/ismej/journal/v4/n3/full/ismej2009127a.html

'Results indicate that permeable Janssand sediments are characterized by some of the highest potential denitrification rates (0.19 mmol N m−2 h−1) in the marine environment. Moreover, several lines of evidence showed that denitrification occurred under oxic conditions. In intact cores, microsensor measurements showed that the zones of nitrate/nitrite and O2 consumption overlapped.'

These are just some marine examples, there are many more papers on freshwater aerobic denitrifiers, and a lot of positive data that they are more efficient at reducing nitrate than anaerobic denitrifiers.

 

[philbo32]

Seeing as these reactors are kept in a flowing reactor with o2 rich water flowing through it, it is likely that these beneficial denitrifying bacteria are mainly aerobic. Aerobic denitifying, not nitrifying bacteria as nitrifying bacteria do not like organic material and therefore are unlikely to be found in any great numbers in the rice reactor. When the reactor is stopped in the case of the OP the oxygen demand from these bacteria would cause them to die or become dormant as O2 deminishes. This would allow the anaerobic denitifying bacteria and sulphur bacteria to start growing and cause the problems that the OP has encountered with poisonous H2S (byproduct of there respiration).

 

[thebanker]

Wait a minute, I thought we were talking about denitrification through the production of bacterial biomass - creating new cells, not denitrification via bacterial respiration processes.

 

[philbo32]

Thats so much work. Does anyone else see it this way?

I meant it to read a thorough rinse followed by 3 days of soaking in RO water, replacing RO every 24 hours. Sorry for any confusion. I don't think that this would be that much work.

 

[philbo32]

Wait a minute, I thought we were talking about denitrification through the production of bacterial biomass - creating new cells, not denitrification via bacterial respiration processes.

Denitrification occurs through the respiration of specialist bacteria using nitrate as an oxygen source, they need carbon and phosphate for food to grow and multiply.

So we are talking about removing nitrate (phospate and carbon) using bacteria and then skimming off any excess bacterial biomass that leaves the reactor via your skimmer.

 

[thebanker]

No I gotcha, it's just a heck of a lot of work to have to do a 3 day soak every 2 weeks or so.

 

[DJREEF]

Wait a minute, I thought we were talking about denitrification through the production of bacterial biomass - creating new cells, not denitrification via bacterial respiration processes.

I think they're still debating the bio dynamics surrounding kkill's sump situation. Somehow the 2 topics have kind of converged.

DJ