Treatment Of Landfill Leachate By Anaerobic Filter And Aerobic Contact Oxidation-Fenton-Activated Carbon Combination Process

Landfill, as the primary means of municipal solid waste disposal today, produces a large amount of landfill leachate during its process. The landfill leachate contains high concentration pollutants, and it has complex composition. Furthermore, the water quality and quantity change a lot. Therefore, it has been generally known as a kind of wastewater and which is quite difficult to deal with. With the launch of the new Standard for Pollution Control on the Landfill Site of Municipal Solid Waste, to find an economic and effective way to treat landfill leachate becomes an urgent and challenging task for the local govemment. This study carried out the research about treatment of leachate from Laohuchong Landfill site in Shenyang. A combination process’Anaerobic Filter and Aerobic Contact Oxidation-microwave-Fenton-Activated Carbon’has been developed. The results showed that the CODcr removal rate of the leachate was up to90%, under the optimum technological parameters of this process.The anaerobic biological filtration process-aerobic biological contact oxidization technology was applied for the treatment of leachate. Higher molecular material B was used in this technology as the filling, which provides microorganisms a carrier for growing environment. It increased the number of microorganisms, and enhanced the removal rate of the pollutant. While the material itself had a strong ability of adsorption of pollutants, and it is more favorable to remove the pollutants. When the HRT of anaerobic biological filter was8d, the HRT of the aerobic biological contact oxidation was12h, the removal rate of CODcr、TP、TN and NH4+-N could achieve81.6%,72.1%,67.7%and93.2%. Besides, this could make the subsequent adjustment of pH become much easier and economic. After the leachate was alkalinized by CaO, the humic acid, heavy metals and the phosphorus content of the raw water contained in leachate could be effectively removed.After the landfill leachate was treated through biochemical and alkalinizing treatment, the effluent was pretreated using microwave-Fenton-activated carbon process. The best reaction conditions of Fenton was:in every25mL waste water, the initial pH=2.5, the dosage of H2O2was0.3mL, the H2O2/Fe2+molar ratio was7:1, and the reaction time was60min. The CODcr removal rate of wastewater reached89.9%. The best reaction conditions of microwave-Fenton were:in every25mL wastewater, the dosage of carbon was0.2g, load capacity of iron (Ⅱ) was437.36mg/g, and the reaction time was4min. Under the optimum conditions, in microwave-Fenton, the CODcr effluent concentration of leachate was854.2mg/L. Finally, under the combination process, the total removal rate of CODcr, TP, TN and NH4+-N were92%,99.4%,94.9%and92.2%.