ADVANCED TREATMENT OF LEACHATE BY A BIPOLAR THREE-DIMENSIONAL ELECTRODE REACTOR

Electrochemical decomposition of leachate, which has previously undergone A/O (anaerobic-aerobic biological) treatment and chemical coagulation, was investigated over Ti/RuO sub(2) times IrO sub(2) anode, stainless steel cathode and coke powder particle electrodes packed into the electrodes in a bipolar three-dimensional electrode reactor (BTDR). The removal efficiency of COD and ammonia nitrogen increased with applied current density. The main influencing factors of BTDR were evaluated by an orthogonal test including reaction time, current density, plate distance, plate amounts and aeration flow-rate. With reaction time of 80 min, current density of 25 mA/cm super(2), plate distance of 1.0 cm, plate amounts of 4 pairs, and aeration flow-rate of 2 L/min, most of contaminants in leachate were decreased by BTDR, which can supply the discharge limit for landfill leachate in China. The BTDR could be employed as a step of advanced treatment for landfill leachate.