Treatment of leachate generated from bioreactor landfills

Leachate generated from Municipal landfill sites is usually contaminated with organic compounds as well as inorganic pollutants. Leachate needs treatment before being entered to any receiving water body. It is desirable that the leachate should be treated on-site efficiently and cost effectively, particularly for small and remote landfills. The existing processes used for the treatment of leachate often exhibit problems related to treatment time, size, and cost. This study focuses on the development of a low cost treatment method to resolve the existing problems related to on-site leachate treatment and handling. The developed method involved the treatment of given leachate in an anaerobic lagoon with Fenton's reagents followed by aerobic lagoon. The leachate used for the treatment was generated from four solid waste bioreactor landfill models (anaerobic and aerobic) that have high moisture content and high organic concentration of solid waste. The effect of pH control and the different concentrations of Ferrous Sulphate (FeSO₄) and Hydrogen peroxide (H₂O₂) on anaerobic and aerobic lagoons performance were examined in the treatment process. It has been observed that the Fenton's reagents with the ratio of 1:1 have a great influence on COD reduction. The maximum COD reductions with pH in the ranges of 6-7 and 3-4 along with Fenton's reagents have been observed to be 6% (39130 mg/l to 36450 mg/l) and 32% (39130 mg/l to 26430 mg/l) respectively. The overall COD concentration reduction using the proposed treatment was observed to be 50% during the whole treatment process.