Treatment of landfill leachate by an electrocatalytic oxidation process

By replacing the conventional insulating material in a bipolar packed bed cell with a CuO-CeO2/γ-Al2O3 catalyst, heterogeneous catalytic reactions can be carried out in an electrochemical reactor. The morphology and microstructure of the catalyst were characterized by scanning electron microscopy and X-ray diffraction. The effects of varying cell voltage, pH, airflow and electrode span on the treatment of landfill leachate were investigated. The results indicated that the reactor had a beneficial effect on the degradation of landfill leachate. Under the conditions of an applied voltage of 15.0 V, pH of 7.0, airflow of 0.08 m3/h, and an electrode span of 3.0 cm, the removal efficiencies of COD and ammonia-nitrogen (NH4+-N) reached 93.7% and 100%, respectively. In addition, the electrocatalytic system was stable and the removal efficiencies of both COD and NH4+-N remained above 70% even after the reactor was run twenty times. It was shown that the electrocatalytic oxidation results in refractory organics being mineralized or decomposed into small organic molecules and NH4+-N being converted into nitrogen gas and water.