Research Of Leachate Collection Layer Structure On Waste Degradation Effect In Semi-aerobic Landfill

Sanitary landfill is the main method our current urban refuse disposal, have saveinvestment, low operaton cost, strong adaptability and other characteristics.But thesanitary landfill also exist high leachate organic pollution concentration, processingdifficulties, presence of landfill gas pollution and landfill stabilization time and otherissues.As the semi-aerobic landfill technology, greatly improve the sanitary landfillleachate shortcomings, but still higher concentrations of organic pollution.In order tofurther improve the semi-aerobic landfill environmental conditions, promote thedecomposition of organic matter and accelerating landfill stabilization,this researchthrough the improvement of leachate collection layer structure, improved oxygentransmission conditions in landfill leachate collection layer distribution, strengtheninglandfill body biological filter bed function,to promote the degradation of organic matter,nitrogen conversion and landfill leachate’s fast stable, reduce the pollutant concentrationand reduce the harmful gas,the paper research on leachate collection layer structuresemi-aerobic landfill oxygen concentration distribution and landfill gas generationeffect,leachate collection layer structure on landfill leachate quality variation influenceand build the organic matter degradation kinetics model based on the improvement ofleachate collection layer structure.Through the research we got the following mainconclusions:①The oxygen contention in the waste of landfill column performed as aupper-layer> middle-layer>lower-layer; Increase of the leachate collection layer height,can increase the oxygen contention in the leachate collection laye, increase the oxygendiffusion range in the collection layer, thereby increase the contact area between oxygenand waste body, facilitate oxygen diffusion in prophase; Use smooth pebbles as leachatecollection layer material, is not conducive to the diffusion of oxygen; ceramsite as asleachate collection layer material, have certain effect on oxygen diffusion;②Increase the leachate collection layer height can improve the removal rate ofCOD and total nitrogen, and can fast increase the removal rate of COD at97%, totalnitrogen removal rate over90%, as the follow-up continued to reduce COD and totalnitrogen concentration later; pebble leachate collection layer of COD, ammonianitrogen and organic nitrogen removal rate are worse than gravel; gravel collection layersurface with ceramsite, can increase COD removal effect in the late refractory; ③The right height and material of leachate collection layer can better control thelandfill gas methane emission and can better reduce the hydrogen sulfide and odorproduction. impact the environment. Increase the leachate collection layer height, caninhibit methanogenesis; smooth pebbles because of its poor oxygen diffusion capacity,resulting in inhibition of methanogenesis is the worst effect;④Calculation by the Matlab,get the leachate COD biochemical degradation rateconstant, performed as4#=6#>3#>2#>1#>5#, indicate that increase the leachatecollection layer height, in the early stage can improve the leachate COD degradationrate; use smooth pebbles as leachate collection layer,the leachate COD degradation rateis minimum; the combination of different leachate collection layer structure of leachateCOD biochemical degradation rate parameters optimized, suggestions for practicalaerobic landfill leachate collection layer height selection range for60-120cm.