Simultaneous Removal of COD and Ammonia Nitrogen Using a Novel Electro-Oxidation Reactor: A Technical and Economic Feasibility Study

Abstract

A novel industrial-scale electro-oxidation device was built for simultaneous removal of Chemical Oxygen Demand (COD) and ammonia nitrogen in wastewater. The specific currents had a strong effect on removal rate and total current efficiency. At a specific current of 1440 A/m 3 and electrolysis time of 40min, the concentrations of COD and ammonia nitrogen in effluent decreased from 128.75 mg/L and 69.18 mg/L to 50.0 mg/L and 5.0 mg/L, respectively. The stepping control for the specific current is useful for saving energy, and total current efficiency increased from 57.61% to 69.05% in response to use this stepping control model. The energy consumption was 4.34 kWh/m 3 , the total operation cost for one ton of effluent was about $0.574 and the specific capital cost was $420/m 3 /d. These findings indicate that the electro-oxidation process is capable of simultaneously decomposing refractory organics and ammonia nitrogen in wastewater.