Abstract
A model to aid in the design of multiple liner systems, based on physical and chemical properties of the liner materials, would be useful to predict the proper combination and arrangement of barriers to minimize the leakage from hazardous waste containment facilities. A numerical simulation model with a user-friendly interface was developed to study the transport of hazardous chemicals through a composite liner system consisting of a combination of flexible membrane liners, compacted clay liners, sorptive liners (activated charcoal), vapor extraction subsystems, and drainage subsystems. The model was based on an implicit finite difference solution of the combined diffusion and mass flow equations for each layer, with liquid phase having different mobilities. The solution scheme was Newton-Raphson based on the continuity equation for mass balance. Transport of contaminants through flexible membrane liners was accounted for by simulating leakage through flaws and diffusion through the flawless plastic. Simulation of flow through carbon liners emphasized sorption. Volatile extraction was considered in modelling the drainage system. The model was coded in C programming language and has a HyperCard interface, that allows the user to choose the order, number, and thickness of layers along with the physical and chemical properties without directly editing, recompiling, and linking source code. A contaminant index helps the user to choose the desired chemical in the simulated flow.
Mohammed, Kifayathulla (1993). Model to aid the design of composite landfill liners. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1993 -THESIS -M697.