극전환 전해반응기를 이용한 암모니아 제거 및 순환여과식 양식장 적용

Abstract

The recirculating aquaculture is a closed system that reuses aquaculture wastewater. This system has merits of spending minimum seawater and little change in temperature by external factors. However, it has problems of waste material accumulation in fishtank and rapid rise in the ammonia level. Now a days, electrolysis is being applied in the recirculating aquaculture system which is similar to chlorination by hypochlorite. In this study, electrolysis with switching poles were explored to study the characteristic of removal efficiency of ammonia and the phenomenon of polarization by precipitates. First, current, which is the most important factor for product of free chlorine, was lower at the same potential in the electrolysis. By reason of decreasing current, yield of free chlorine is declined. Therefore, it should be prevented fouling phenomenon by switching poles. The period of switching poles equal to 60 second was optimum for high formation efficiency of free chlorine and low fouling phenomenon. In the electrolysis of wastewater, the operating parameters of the electrochemical reactor were the current density and the number of cycles. The removal efficiency of ammonia and the generation of free chlorine were increased by rising the current density and the number of cycles. For 240 hours in the pilot-scale aquaculture system, the concentration of ammonia in the reservoir tank should be kept below at 0.2 mg/L. For 8 cycles a day and 80 A of cell current, it can be kept at 0.2 mg/L.