Abstract
Waste brine water which was supplied by Nippoh Chemicals Co. contains more than 200 mg/L of ammonia, which can be removed by electrochemical treatment of the water. During the treatment process, some of the chloride contributes to the degradation of ammonia, and the remaining chloride leads to the production of trihalomethanes (THMs). In this study, we investigated the effects of various cathode materials and controlled electrode potentials on ammonia degradation and suppression of THMs production. Stainless steel (SUS), Pt, Cu, a Cu and carbon complex (C/Cu), and carbon (C) were used as cathode materials. The SUS cathode, which was widely used until now, had the highest THMs production rate of 5.4 × 10-4 mg·L-1·C, and the lowest current efficiency of 23.3 %. The C/Cu electrode showed the highest current efficiency (36.9 %), and the THM production rate was as low as 4.3 × 10-4 mg·L-1·C. In addition, the C/Cu electrode was the best for removal of total nitrogen: the removal ratio reached 87.3 % in 47 minutes. The results of this study may provide useful information for ammonia removal from agricultural drainage.
