| The objective was to compare water quality and fish growth and mortality in a pilot scale recirculating system (RS) and a control tank in flow through system (FTS). The RS was designed after the Danish Model Trout Farm and operated with a make Lip Water renewal rate of 9 m(3) kg(-1) of fish produced. RS water quality did not decrease significantly with water flow rate decrease in the RS. During the experiment, the RS water treatment system presented solids removal efficiency of 59.6 +/- 27.7% d(-1), ammonia oxidation of 45 +/- 32 g m(-3) d(-1), oxygenation yield of 392 +/- 132 g of O-2 kWh(-1) and CO2 degassing of 23.3 +/- 11.9% pass(-1). In the RS, nitrite concentration was 0.15 +/- 0.07 mg l(-1), close to the toxicity threshold; a N-2 supersaturation... |
