Study on the effect of electrochemical technology on removing inorganic nitrogen from tail water of mariculture

In order to study the electrochemical technology on removing ammonia nitrogen and nitrite in mariculture tail water, the tail water from a mariculture plant in Yangjiabo Town in Tianjin was chosen as the research object. The effects of voltage, electrode plate spacing and electrochemical treatment time on the removal rate of ammonia nitrogen and nitrite were investigated by using dimensionally stable anodes (DSA) electrode and intermittent flow treatment mode, and the energy consumption was analyzed. The results showed that the ammonia nitrogen removal rate reached 96.0% and the energy consumption was only 0.079 kW·h/g when the electrode plate spacing was 2 cm, the voltage was 3 V and the electrochemical treatment time was 5 min. Under the condition of electrode plate spacing of 3 cm, voltage of 3 V and electrochemical treatment time of 7 min, the removal rate of nitrite was the highest, reaching 98.9%. The minimum energy consumption for nitrite removal was 0.032 kW·h/g, and the removal rate was 75.2%. The total inorganic nitrogen in the tail water reached the first-level discharge standard of Water Drainage Standard for Sea water Mariculture (SC/T 9103-2007) after electrochemical treatment in 14 groups in the designed experiment. In conclusion, the electrochemical technology had a good removal effect on ammonia nitrogen and nitrite, and the removal rate of ammonia nitrogen and nitrite was high under different test conditions, and the energy consumption was low.