Effluent water quality of fish laboratory at Norwegian University of Life Science (NMBU)

M-AA

English. The fish laboratory at Norwegian University of Life Science (NMBU) is a moderncenter for fish experiment with a recirculation aquaculture system. The main effluentwater is overflow from recirculation aquaculture system (RAS), the quality ofoverflow is equal to system water. However, the main effluent water (overflow) isrequired to be pump to the municipal water treatment plant. The objective of thisstudy is to understand the water quality of the main effluent water by measuringconcentration total nitrogen (TN), total phosphorus (TP), total suspended solid (TSS)and chemical oxygen demand (COD). Samples was taken every 2 hours from 7:00 to19:00 at January 18th and February 15th2018. The result showed that the average TN,TP, TSS and COD concentration at January 18th was 5.59 mg/l, 0.21 mg/l, 0.61 mg/land 16.03 mg/l respectively. The TN, TP, TSS and COD concentration at February15th was 5.2 mg/l, 0.152 mg/l, 0.472 mg/l and 5.83 mg/l. The concentration of theseparameters was lower compare with the outlet water of municipal waste treatmentplant (Søndre Follo) in Vestby. This suggests that the treatment in Søndre Follo doesnot significantly increase the water quality of the main effluent water from fishlaboratory at NMBU. However, it will load the municipal plant with water that iscleaner than the outlet. The amount of TP, TN TSS and COD produced by 1kg feedsupplied was 17.17 g, 0.56 g, 1.71 g and 33.2 g, respectively. In addition, the amountof TP, TN, TSS and COD discharged with main effluent water was estimated at 23.9kg, 0.79 kg, 2.37 kg and 46.1 kg per year. One possible solution is to set the effluentwater to lake in close area called Årungen. The amount of TP discharge to Årungenwith stream will be increased with 0.025%.