Features of numerical modeling of the spread of leachate in the base of a municipal solid waste landfill

The article presents the results of a numerical study of seepage water dynamics in the base of a municipal solid waste (MSW) landfill. The landfill is a complex engineering structure that receives, stores, and isolates waste in order to provide effective waste disposal management and ecological safety. During the life of a MSW landfill, contaminated runoff, or filtrate, is formed. The negative impact of the filtrate formed in the landfill body is associated with the possibility of its penetration into groundwater and, as a consequence, into surface water bodies. When organizing a landfill, a substrate in the form of an anti-seepage screen, which performs a barrier function, is laid. In numerical modeling of the filtering capacity of the screen, the filtrate layer is not considered. In this paper, the effect of the technogenic layer on the modes of diffusion and convective propagation of seepage waters in the base of municipal solid waste placement facilities was numerically investigated. To study the features of pollutant distribution and to determine migration parameters, archival data from a set of field and laboratory studies in the area of the operating landfill were used. A numerical model describing the hydrodynamics of substance migration in the soil layer was constructed. The process of pollutant movement is described in terms of dry residue dissolved in water. Factors that have a significant impact on the migration of MSW ingredients, such as convective transfer, diffusion and the geological composition of the landfill base, are taken into account in the mathematical formulation of the problem. It is shown that the instability lead.