Numerical modelling of leachate production and movement within landfill sites

Rights statement
Awarding institution
  • University of Strathclyde
Date of award
  • 1996
Thesis identifier
  • T8738
Qualification Level
Qualification Name
Department, School or Faculty
  • This research project considers the development of numerical simulation processes of the production and management of leachate from landfill sites. The existing landfill leachate management models are reviewed and analysed on the basis of their applicability and effectiveness, identifying a number of important deficiencies in these models. These models simplify the actual flow process in the waste matrix and assume the same density throughout the simulation period. Moisture flow through waste material is investigated through experiments, and as a result different mathematical models were developed. These models represent the effect of density on the hydraulic properties of waste material such as: moisture capacities, drainage rates and saturated hydraulic conductivity. The effect of density is identified as the fundamental parameter governing the flow phenomena in waste material. A large database of information obtained provides a better interpretation of statistical analyses, in fitting statistical distributions to parameters and to cover the variability of waste material. A basic applied numerical model named NUMMOL (NUMerical MOdelling of Leachate) is developed based on the water balance approach, which simulates the leachate production, movement and distribution within landfill sites. NUMMOL incorporates the most appropriate mathematical models representing the various landfill hydrological processes. The moisture flow through waste layers is modelled using the models derived through experimental investigation. The model's limitations and assumptions are discussed with suggestions for future work that is necessary to enhance further its applicability. Sensitivity analysis and evaluation of the simulation capabilities of the NUMMOL model are included. It was found that correct identification of the hydraulic properties of the landfill material is very important. To investigate model usefulness and efficiency as an environmental planning tool, the individual components of the model are evaluated. It was found that the model iterative scheme is very effective in simulating leachate movement in a cell and leachate distribution within cells. The model was applied to the landfill site in order to compare the effect of layers on leachate distribution.
Resource Type
Date Created
  • 1996
Former identifier
  • 500653