Why BADES
Why BADES
Why installing an autotrophic denitrification capacity using elemental sulphur?
Why nitrates may build up in a well lit aquarium and are not used up by photo-autotrops? Insufficient supply of other building materials may be the reason.
When food is consumed most of the nitrogen is released as ammonia and urea and organic waste. The same time a skimmer removes continuously part of the organics (building materials) in a very selective way leaving polar and hydrophilic compounds behind for remineralisation, the production of building materials. During remineralisation most organic carbon is transformed to inorganic carbon to be reused by autotrophs. But the photo-autotrophs are not able to assimilate the nitrate- nitrogen as the building materials needed are continuously removed.
Ammonia is constantly used by heterotrops and other organisms to grow, and by autotrophs for energy. To reduce the same amount of ammonium the heterotrophs need 40x more building materials as the autotrophs need for nitrification.
The first thing we have to do when starting up an aquarium is installing the carrying capacity which is based on the ability to reduce ammonium. Most reefers have banned the biofilter this way limiting the carrying capacity and lost the comfort of easy adjustment of the carrying capacity.
The second thing to do should be installing the capacity to export the nitrogen overproduction, this when a skimmer is used. This second step is by most reefers looked over and they will try to find a solution when confronted with the fact a skimmer creates unbalance.
Not doing the second step leads to the question: What to do with the nitrate produced by a biofilter? Was it solved it by removing the bio filter!?
When on fora the question is repeated " What to do with nitrates?" the first response will be " try vodka dosing"
But as the reason for nitrate build up is in most cases insufficient supply of some building materials where will the building materials come from to support the fast heterotrophic growth induced by vodka dosing? Well, they will outcompete most organisms who where using the ammonium and building materials before dosing messing up the created balance and most important will remove the installed autotrophic carrying capacity. Bacteria prefer ammonia- nitrogen for fast growth. And heterotrophic assimilation does not remove the nitrogen from the system but stores it for later reuse.
This is not what I want!
In the second step one has to decide what to do with nitrogen overproduction.
Provide the building materials needed for photo-autotrophic growth for supporting the system or for removal by harvesting?
Or are we going to remove the nitrogen directly as nitrogen gas? Or both?
We where looking for a way to export nitrogen overproduction and the same time will give full control over the nitrate level and make it possible to close the nitrogen cycle in the system The presence of nitrate is very important for the biological balance in a closed system.
We found the solution in autotrophic nitrate reduction by sulphur bacteria.
As we where looking out for a safe and reliable way to use the BADES process we have deleted anoxic kept denitrators from the possible solutions.
Starting from the MAAO method and the knowledge in any biofilm denitrification can take place our research lead us to the application of sulphur columns and a BADES biofilm reactor.
All info about a BADESS:
http://www.baharini.eu/baharini/doku.php?id=en:badess:start
A reactor as proposed in this building project can be used in a BADES System. The condition is that the reactor is NOT kept anoxic and the reactor is big enough to support the system.
