Two-dimensional numerical analysis of landfill contaminant migration considering non-linear adsorption

A two-dimensional contaminant migration governing equation was established considering the waste degeneration,the non-linear adsorption characteristics of the compacted clay liners(CCL),the linear adsorption characteristics and the anisotropy of the aquitards and the aquifers and assuming that the lower part of the landfill should have three layers of soil,and the seepage field should be steady.The numerical analysis was carried out as regards some imaginary landfills.Through the computation and the analysis of change parameters,the contaminant concentration contours were obtained.The results indicate that the vertical hydrodynamic dispersion coefficient of CCL and the aquitards is the sensitive factor for the contaminant migration process.Only considering the non-linear adsorption characteristics of CCL,the combined parameter Sl,m is the sensitive factor for the contaminant migration.When the value of Sl,m is larger,the lateral migration ability of the contaminant increases,bu is not sensitive to adsorption intensity Kl,l.The effect of the linear adsorption of the aquitards on the contaminant migration is remarkable,that of the aquifes is weaker.