Study On Scaling And Corrosion Of HDPE Pipeline Material In Leachate Transportation

Landfill leachate is a kind of secondary pollutant which is produced by landfill.Landfill leachate has the following obvious characteristics:various kinds of pollutants,high organic matter content,complex water quality,large changes in water volume,high NH3-N content,high content of heavy metal ions and nutrient imbalance.Landfill leachate,because of its complex components,may give rise to corrosion and scaling during pipeline transport,thus result in leakage to damage environment.Therefore study on scaling and corrosion of pipeline material in landfill leachate transportation is the premise to ensure the leachate transport in a safe and reliable way,which provides insight into operation safety of landfill.In this paper,I took the predecessors' research as a basis and set the landfill of Chengdou as the study basis to analyze the reasons of the scaling and corrosion of pipeline material in landfill leachate transportation.The methods of literature reading and field investigation were used to understand the problems in the transport of landfill leachate and the type of pipe material.From these three aspects which are environmental factors,the nature of the leachate itself and the characteristics of the material itself to in-depth study what results in scaling and corrosion of the landfill leachate transport pipeline material.Finally,the parallel comparison experiment was used to compare PVC pipe and HDPE pipe to verify the correctness of experience material selection.The following conclusions can be drawn from the experiment.(1)Landfill leachate transport pipeline material HDPE scaling and corrosion phenomena are caused by a series of complex reactions such as chemical reactions,biological reactions and physical reactions.(2)Under the same concentration of organic matter,the dominant factor of scaling of HDPE pipe material is the chemical precipitation of Ca2+ and Mg2+.The scaling of HDPE pipe material is closely related to the concentration of organic matter in landfill leachate.(3)The Experiments show that the rising of the temperature,the environmental oxygen content,the concentration of Ca2+ and Mg2+ in landfill leachate,the pH of landfill leachate and the rainfall of Chengdou lead to the increase of the amount of scaling of HDPE pipe material in the transport of landfill leachate.(4)The corrosion phenomenon of HDPE pipe material in the transport of landfill leachate can't be ignored.In the high temperature and hypoxia condition,the molecular bonds of HDPE pipe surface are broken and the surface of HD PE pipe material appears many obviously cracks.(5)In terms of material selection,the result of the experiment is the same as that of the experience.