Water treatment system in a fish tank for intensive fish farming

摘要

The water treatment system (12) includes a flooded fixed-bed reactor (22) for the microbiological water treatment, in particular the elimination of nitrogen. Below the fixed-bed reactor (22) there is located a first aeration unit (26) through which air is passed in and water is conveyed through the fixed-bed reactor (22) in a rising flow by the air lift pump effect. Downstream of the fixed-bed reactor (22) there is arranged a degassification and coagulation zone (72), a sedimentation zone (74) and a second aeration unit (52) through which air or, preferably, oxygen, is passed in, and the water is enriched with oxygen. The oxygen concentration of the water flowing back into the fish tank (10) is in this manner decoupled from that of the microbiological water treatment from the control engineering point of view. IMAGE