Study On Physical And Chemical Treatment Of Advanced Landfill Leachate

Advanced landfill leachate produced in Yang'er yu landfill of Anshan was pretreated with internal electrolysis and the biochemical treated landfill leachate was treated deeply with Fenton oxidation process as well as the treated costs was analysized in the study.The results showed that internal electrolysis could be used to pretreat the advanced landfill leachate in the condition of alkalescence, with which could not only remove part of COD and chromaticity, but also improve the biodegradability of the leachate. The pretreated leachate could be biochemical processed directly without dilution, so can make the load of bio-treatment improved obviously.The factors which influence the treating efficiency of advanced landfill leachate with internal electrolysis and Fenton oxidation process were studied . he results indicated that the lower pH the better treating effect with internal electrolysis ,but the costs is very high for adjusting the pH. In the condition that the pH of untreated leachate was not adjusted (the pH was 8.0-8.5 ) , the optimal terms were as follows: the dosage of the iron was 19g/L, the ratio of iron and carbon was 1:1.4 and the reaction time was 40min. In addition, the mixing intension, activation of the electrode materials, the particle of iron and carbon, adscititious electrolyte and the electrode material also influenced the treating efficiency. The maximum removal efficiency of COD may reach to 45% , the removal efficiency of chromaticity can be more than 61% and the ratio of BOD/COD can be raised from 0.1 to 0.28 under above conditions. The optimal terms of Fenton oxidation process were as follows: the initial pH was 7.0, H₂O₂/Fe²⁺ was 4:1, the dosage of H₂O₂ was 30mmol/L and the reaction time was 2h. The removal efficiency of COD can be more than 80% as well as the COD was less than 100mg/L and chromaticity was less than 50 in the Fenton oxidation process treated leachate, the quality of effluent could meet the request of the first level of landfill leachate discharged standard (GB16689-1997).Being Y 12.71/t, the treating costs of the advanced landfill leachate with this technology of the Internal Electrolysis - ANAMMOX - Fenton Oxidation Process is much lower than that with the traditional process, which is more thanï¿¥15/t.