Model studies on a recirculation system with a rotating biological filter for fish fattening

Part I. Preliminary model studies on the rotating drum filter

Abstract

A new rotatory biological filter was worked out and constructed on the basis of available literature. Studies on its effectiveness were made in a model recirculation system with a stock of silver and common carp. Some difficulties were noted as to the initiation of the phase II of nitrification. They resulted in a dangerous increase of nitrite content (maximal nitrite content reached 0.63 mg N-NO₂ per dm³). Amount of suspended organic matter reached 30 mg/l.