EFFICIENT ELECTROCHEMICAL AMMONIA REMOVAL SYSTEM

Efficient electrochemical ammonia oxidation system was studied with an objective to enhance the selectivity of ammonia to nitrogen gas and to remove the by-products in an undivided electrochemical cell, in which various cathodes (Ti, Cu/Zn, Fe) and Ti/IrO 2 -Pt anode were assembled.In the present study, anodic oxidation of ammonia and cathodic reduction of by-products were achieved, especially with Cu/Zn cathode.The ammonia-N decreased from 100.0 mg/L to 0.0 mg/L in the presence of 1.0 g/L NaCl after 120 min electrolysis at the current density of 30.0 mA/cm 2 with Cu/Zn cathode and Ti/IrO 2 anode.No nitrite was detected in the treated solutions.The concentration of chloramine was 0.24 mg/l.About 97.34% of initial TN was transformed into nitrogen gas in Cu/Zn system, indicating that Cu/Zn cathode has better performance than Ti and Fe cathode.The results indicated that Cu/Zn cathode exhibited a little higher reduction ability, possibly attributed by the higher electrocatalytic activity of brass containing Zn (35-41 wt%) which significantly influenced the kinetics of current density.As ammonia could be completely removed by the simultaneous oxidation and reduction in this study, it is suitable for deep treatment of ammonia polluted water.