Experimental research on treatment of landfill leachate byboron-doped diamond anode in three electrodes system

Electrochemical oxidation of mature landfill leachate was conducted in three electrodes system using boron-doped diamond electrode as anode. The effects of four operating parameters such as dilution ratio, initial pH, current density and electrode gap on the removal efficiency of ammonia nitrogen and COD were investigated. Experimental results show that current density and dilution ratio are the determinable parameters affected the electrochemical oxidation efficiency of landfill leachate. Initial pH value and electrode gap have a little effect on efficiency of electrochemical oxidation. Under the optimal conditions (e.g. dilution ratio of 1∶2, current density of 75 mA/cm², no adjustment of initial pH and electrode gap of 10mm), complete abatement of NH₄⁺-N and COD were achieved after electrolysis of 5 hours. Linear function y=21.759 t, y=20.717 t is well fit to experimental data of NH₄⁺-N and COD removal rate, respectively. The related correlation coefficients are 0.9923 and 0.9925, respectively. Energy consumption of electrochemical oxidation on BDD anode is 260 kWh/m³, under the optimal conditions.