Application of Electrochemical Process in Removal of Heavy Metals from Landfill Leachate

Aims: Municipal landfill leachate contains high concentrations of heavy metals, organics, ammonia . T he efficeincy of electrochemically removal of heavy metals from landfill leachate was studied. Materials & Methods: The leachate was obtained from Kahrizak landfill in south of Tehran. The experiments were carried out by batch process. The 2liter batch reactor was made of glass. There were eight anodes and cathodes electrodes. The electrodes were placed vertically parallel to each other and they were connected to a digital DC power supply. The pH and conductivity were adjusted to a desirable value using NaOH or H2SO4, and NaCl. All the runs were performed at constant temperature of 25 ° C. In each run, 1.5liter of the leachate was placed into the electrolytic cell. Samples were extracted every 10min and then filtered through a mixed cellulose acetate membrane (0.42μm). The amount of Lead, Zinc and Nickel removal was measured at pH=7 and in current density of 0.5, 0.75, and 1A. Findings: When current density and time reaction increased, removal efficiency of heavy metals such as Lead, Zinc and Nickel increased. At initial pH=7, density 1A and reaction time= 60min, Lead, Nickel and Zinc were removed up to 86, 93 and 95%, respectively. Conclusion: Electrochemical process can be proposed as a suitable technique to remove heavy metal from landfill leachate.