Influencing factors on ammonia removal by electrochemical oxidation treatment

To investigate the degradation of low-concentration ammonia in wastewater by electrochemical oxidation, the effect of various operating factors on ammonia and total nitrogen removal were studied. The experimental parameters were anode, cathode material, current density, chloride concentration, electrode gap, initial ammonium concentration and three-dimensional particle. Both the performances of two-dimensional and three-dimensional electrode were discussed. The results show that electrochemical oxidation is suitable to degrade ammonia from wastewater, and the optimum operating parameters are 1 cm electrode gap, 5 mA/cm2 current density, 200 mg/L chloride concentration, RuO₂-IrO₂-SnO₂/Ti as anode, titanium mesh as cathode, and modified zeolite as three-dimensional particle. Under the optimal conditions, 95% of ammonia is removed after 20 minutes' electrochemical oxidation. The synergetic effects of several physical-chemical processes achieve ammonia removal in the three-dimensional system. Compared to two-dimensional system, ammonia removal and current efficiency are higher in three-dimensional system.