Bpr

[Belgian Anthias]

A question for the chemists.

I am doing some research concerning BPR(biological phosphorus removal) and I found this : A. Sathasivan
Department of Civil and Construction Engineering, Curtin University of Technology,
Perth WA 6845, Australia.
Key Words: Biological phosphorus removal, Enhanced biological phosphorus removal (EBPR), wastewater treatment, phosphorus, biological nutrient removal (BNR)processes, Phosphorus accumulating organisms (PAOs),
Accumlibacter, Competibacter
.
Presence of carbon and phosphate sources at the same time under aerobic or anoxic conditions has negative effects on phosphorous
uptake (Smolders et al., 1994, Kuba et al 1994; Brdjanovic et al., 1998). Carbon sources available under these conditions will be primarily utilized for PHA formation. Only when the external carbon sources are exhausted, phosphorous uptake occurs (Mino et al., 1998). Therefore, simultaneous presence of electron acceptors (including carbon sources) and phosphate should be avoided.

Assuming that the above is correct I would like to know if the carbon released when calcium carbonate is dissolved would influence the phosphate uptake?
How phosphate uptake is accomplished using bio-pellets as a carbon source is always available?

 

[bertoni]

I'm sorry, my chemistry background is too weak to say much, but saltwater contains enough carbonate and carbon dioxide that I doubt that the small amount added by sand or reactor media dissolution is going to make a difference.

 

[Randy Holmes-Farley]

I don't how this would apply in seawater where carbon sources (such as bicarbonate) are plentiful.

 

[Belgian Anthias]

Ebpr

Ebpr

I discussed this with a friend and the explanation was that BPR ( biological phosphorus removal) is not the same as EBPR(Biological P-removal using enhanced biological phosphorus removal)
BPR is feeding phosphorus accumulating bacteria organic carbon so they multiply and take up phosphorus in their tissue.( bio-pellets - VODKA)
EBPR is phosphorus accumulating bacteria who release phosphorus in anoxic conditions and take the released phosphorus back up and a lot more when oxygen rich water is provided this way reducing phosphorus level in the water
So it is EBPR what I am talking about.

My question concerning biopellets is answered because it is an other process.

When effluent from a Sdenitrator enters the calcium reactors, this water may be anoxic, nitrate free and probably free of organic carbon. My idea was to use this water for EBPR. My question is: if the carbon released when the calcium carbonate is dissolved would prevent this process or is it organic carbon A. Sathasivan is talking about with "external carbon sources" in his paper or is this process not possible in seawater at all?

 

[Randy Holmes-Farley]

How do you know if either of these could ever happen in marine aquaria?

 

[Belgian Anthias]

How do you know if either of these could ever happen in marine aquaria?

Manufacturers of bio-pellets claim that using bio-pellets removes nitrate and phosphorus. This is a logic claim because when bacteria are cultivated they need and take up phosphorus and nitrate to grow but bio-pellets remove nothing.. BPR removes phosphorus only when the cultivated biomass is removed from the system. I thought BPR is a common process and one of the reasons for using a skimmer.

We know that when BADESS ( Biological Autotrophe Denitrification with the use of Elemental Sulfur System) is used the level of phosphorus in water leaving the Ca-reactor may be a lot lower than in the entering water but not always. So we thought that this had something to do with the amount of carbon that becomes available when the calcium carbonate is dissolved in the reactor.
EBPR is a natural process and as all live comes from the sea I suspect it to happen in a marine environment.

I am not a chemist and have not the ability to find out how these processes work but I try to find some answers in the drink- and waste water treatment where a lot of research has been going on the last years.

We know also that with BADESS the sulphate production is a lot lower as one would expect. It was suggested that the sulphate was held back in the ca-reactors.
For water treatment in Hongkong, where seawater is used for sanitary purposes, they use sulphate reduction for nitrate removal called the SANI system (sulfate reduction, autotrophic denitrification, and nitrification integrated process (SANI process) for saline sewage treatment )

I think most of these processes also take place in our reactors trying to explain what we experience.

 

[Randy Holmes-Farley]

I'm not following all of those acronyms, and I'm not convinced they even apply in a reef aquarium where totally different things may be happening (such as consumption of the bacteria by higher organisms).

Growth of bacteria removes free phosphate from the water, whether it is skimmed or not.

But ultimately, something must happen to that bacteria (and the phosphate in it) if the bacterium is not skimmed out. If it just keeps living, or is eaten by something, that may keep some or all of the phosphate out of the water column permanently.

If it dies and is broken down completely, the phosphate may return to the water column.

Beyond that simple analysis, I don't think we have a complete picture of the mass balance of phosphate in a skimmed reef aquarium with organic carbon dosing.

 

[Belgian Anthias]

Merry Christmas and a fine and happy New Year 2015

 

[Randy Holmes-Farley]

Same to you!