Abstract:To explore the effect of water treatment and the influencing factors by using the electrochemical oxidation process in industrial recirculating aquaculture system, the research was conducted under the best condition with temperature of 25℃, current density of 40A/m2 and flow rate of 300mL/min, which was obtained by the former study. With different initial concentrations of ammonia nitrogen, suspended solid of simulated aquaculture water and actual aquaculture water of tilapia from the recirculating aquaculture lab of Zhejiang University, the removal rate of ammonia nitrogen was explored by using electrochemical process combined with UV irradiation. It demonstrated that the effect of using electrochemical process combined with UV irradiation was much better than that of single use of electrochemical process. Therefore, under initial concentrations of ammonia nitrogen at 4mg/L, 7mg/L and 10mg/L of simulated aquaculture water, the removal rates of ammonia nitrogen were increased by 45.0% （p<0.05), 36.0% （p<0.05) and 20.0%（p<0.05), respectively. The initial concentration of ammonia nitrogen、the suspended solid in the aquaculture water and the actual aquaculture water had important effects on removal efficiency of ammonia nitrogen, with the increase of initial concentration of ammonia nitrogen and concentration of suspended solid, the removal efficiency was reduced and the spending time was prolonged. For example, the treatment of different simulated aquaculture water with suspended solid of 100mg/L, 150mg/L, 200mg/L, the removal rate of ammonia nitrogen was decreased with the increase of SS, compared with the simulated aquaculture water only containing ammonia nitrogen, the removal rates of ammonia nitrogen were decreased by 51.7% （p<0.05), 65.5% （p<0.05) and 72.4%（p<0.05), respectively. When dealing with actual aquaculture water, although the system had great effects on the removal of ammonia nitrogen (the efficiency was 97.8%), nitrate nitrogen (the efficiency was 96.9%) and suspended solid (the efficiency was 92.1%), the removal rate of ammonia nitrogen was decreased and the time spent was prolonged.
