Construction and application of an electrocoagulation and filtration linkage control system in a recirculating aquaculture system

Total suspended solids (TSS) are the major factors that reduce water quality in a recirculating aquaculture system (RAS). In the present study, electrocoagulation (EC) was used for the first time to increase the particle size of TSS in RAS and improve the filtration efficiency of the microscreen drum filter (MDF) without reducing the filtration pore size. When the aquaculture water was treated using an electrocoagulation diameter increasing reactor (EDIR) for 2 min, with current density at 50 A/m(2) and influent flow at 300 L/h, the D50 of TSS increased by 86.43%. An electrocoagulation diameter increasing reactor and microscreen drum filter (EDIR-MDF) linkage control system was constructed, and its application in the RAS of Litopenaeus vannamei was investigated. The working principle of the EDIR-MDF linkage control system is that the output current of EDIR (J(EDIR)) was feedback controlled by the backwashing interval period of MDF (T-MDF). Results showed that the EDIR-MDF linkage control system increased the average removal efficiency of RAS for TSS, chemical oxygen demand (COD), ammonia, and nitrite by 24.07%, 24.30%, 8.94%, and 1.39%, respectively, and resulted in average energy consumption and anode loss of EDIR of 2.38 kWh/d (1.68 RMB/d) and 370 g/d (2.22 RMB/d).

Automated summary

In this study, electrocoagulation (EC) was used for the first time to increase the particle size of total suspended solids (TSS) in a recirculating aquaculture system (RAS), improving filtration efficiency without reducing pore size. A linkage control system was constructed, increasing removal efficiency for TSS, COD, ammonia, and nitrite in Litopenaeus vannamei RAS by 24.07%, 24.30%, 8.94%, and 1.39%, respectively. The system also resulted in an average energy consumption of 2.38 kWh/d and anode loss of 370 g/d.