Treatment of landfill leachate by Fenton process: parametric and kinetic studies

Fenton treatment of leachate of municipal landfill was investigated in this study. Physical and chemical characteristics of the leachate indicated that the waste is alkaline and is characterized by extremely high concentration of organic compounds. Different reaction conditions of Fenton treatment were examined including H2O2/chemical oxygen demand (COD) and Fe2+/H2O2 ratios in the present work. COD of leachate after Fenton treatment was removed by about 77 and 83% for initial COD 6,250 and 13,300mgO(2)/L, respectively. Such a maximum removal was achieved at pH 3 and using reagent dosages as high as H2O2/COD=4.4 and H2O2/Fe(2+)value of 50. Complete oxidation was not achieved even at optimum conditions due to the presence of inhibitors (carbonate) in the leachate wastewater. After removal of high carbonate content, the same removal efficiency could be achieved with lower H2O2/COD ratio (i.e. H2O2/COD=3.3). A simplified kinetic study for Fenton treatment of leachate wastewater has been performed.