Two categories of Nitrifying Bioreactors are offered to establish Recirculating Aquaculture Systems (RAS):
Both are bio film reactors – with indigenously developed nitrifying bacterial consortia immobilized on cartridges.
Ex-Situ Packed Bed Bioreactor (PBBR)
The reactor is made of fiberglass shells. Each reactor has 9 aeration cells with beads. The beads are designed in such a manner that the specific nitrifying bacterial consortium gets immobilized on the surface of the beads. The Packed Bed Bioreactor contains 60 kgs of beads with a surface area of about 28.26 m² and specific surface area of about 205 m² / m³ to facilitate removal of harmful nitrogenous compounds.
In-Situ Stringed Bed Suspended Bioreactor (SBSBR)
On suspending the reactor one foot below the water level on a float, and operating the airlift pump, water enters the reactor through the perforations on top of the black lid, passes through the cartridge and flows out. When water comes in contact with the immobilized bacteria on the surface of the beads, nitrification takes place and dissolved ammonia in the water is converted to nitrates and subsequently into elemental nitrogen and oxygen. The framework of the inner cartridge is made in such a way that larvae, plankton, and food particles when enters, pass out through the airlift pump without mutilation and damage.Stringed Bed Suspended Bioreactor contains 1001 beads with a surface area > 684cm2.