Depuration efficiency of recirculating aquaculture system in the aquaculture of Anguilla marmorata

We monitored the water quality of rearing tanks and the treatment equipment to study the system recycles efficiency for nutrient removal and to provide theoretical reference for a reasonable water quality regulation and standard producing instruction of operation for aquatic food. The result showed that the average seawater quality were 20.8℃for temperature, 6.8 for pH, 7.890 mg/L for dissolved oxygen, 0.455 mg/L for ammonium, 0.368 mg/L for nitrite, and 17.884 mg/L for COD. The average system removal efficiencies of ammonium, nitrite and COD were 26.16%, 2.22%, and 5.82%,respectively. Survival rates of Anguilla marmorata aquacultured were all higher than 95%. The results showed that increasing the water temperature to 25 -30益, adjusting pH 7.5 -9.5, choosing the right nitrifying bacteria, establishing proper aquaculture techniques, the system could obtain a better removal efficiency for pollution.