Efficiency Research On Anaerobic/Aerobic Backfilling Technology Of Municipal Solid Waste

The landfill leachate treatment is difficult to carry out. In October,2003,ChangChun Sandao landfill started to operate dish tube reverse osmosis systemas landfill leachate treatment devices, the COD <30mg/L of effluent, BOD₅<10mg/L, NH₃-N <10mg/L, which meets one class national discharge standard, theconcentrated leachate which produces in the treatment is recirculated to thelandfill. On the basis of introducing disc-tube reverse osmosis system, this thesisanalyzed its effect and pointed out that the best recovery rate is80%⁸5%.The paper takes concentrated leachate recirculation as the important researchcontent; the experiment was carried out in the experimental devices ofrecirculation. The results indicated that COD removal efficiency was81.56%,BOD₅82.5%, NH₃-N60%⁷0%when recirculating concentrated leachate toanaerobic landfill matrix in methane stage for the recirculated concentratedleachate. When recirculating concentrated leachate to aerobic landfill matrix, theCOD removal efficiency was91%, BOD₅98.69%, NH₃-N94%⁹6%. CODremoval efficiency was72.66%, BOD₅63.28%, NH₃-N26%³5%, they arehigher than the removal efficiency under conditions that concentrated leachatewas not recirculated to landfill matrix. COD, BOD₅and NH₃-N removalefficiency were higher than that for recirculating concentrated leachate to agedlandfill matrix. The removal efficiency of its main metal ions Cu, Zn, Cr, Pb andCd in concentrated leachate were45%at least. Recirculating concentratedleachate can accelerate degradation of the garbage under this experimentalcondition. Garbage package height in concentrated leachate recirculation reactorwas3.75times of the garbage height sedimentation in no concentrated leachaterecirculation reactor after20weeks. On the basis of the experiment, the results pointed out that concentrated leachate recirculation can availably removepollution materials in it. It is a kind of cost-effective and efficient concentratedleachate treatment method.The main influence parameters of concentrated leachate recirculation canaffect the performance of the recirculation. The hydraulic loading rate is themajor influence parameter for concentrated leachate recirculation. Whenhydraulic loading rate was32.38ml/L·d²02.36ml/L·d, COD removal efficiencywas70%⁹4%. Furthermore, organic loading rate, pH, C/N, recirculation-timesalso affect recirculation efficiency. Ideal recirculation efficiency can be attainedby controlling these parameters, so the experiment provides worthy reference forthe actual operation of concentrated leachate recirculation in landfill.