MODELING OF MULTIPHASE TRANSPORT OF MULTICOMPONENT ORGANIC CONTAMINANTS AND HEAT IN THE SUBSURFACE - NUMERICAL-MODEL FORMULATION

A numerical compositional simulator (Multiphase Multicomponent Nonisot hermal Organics Transport Simulator (M2NOTS)) has been developed for m odeling transient, three-dimensional, nonisothermal, and multiphase tr ansport of multicomponent organic contaminants in the subsurface. The governing equations include (1) advection of all three phases in respo nse to pressure, capillary, and gravity forces; (2) interphase mass tr ansfer that allows every component to partition into each phase presen t; (3) diffusion; and (4) transport of sensible and latent heat energy . Two other features distinguish M2 NOTS from other simulators reporte d in the groundwater literature: (1) the simulator allows for any numb er of chemical components and every component is allowed to partition into all fluid phases present, and (2) each phase is allowed to comple tely disappear from, or appear in, any region of the domain during a s imulation. These features are required to model realistic field proble ms involving transport of mixtures of nonaqueous phase liquid contamin ants, and to quantify performance of existing and emerging remediation methods such as vacuum extraction and steam injection.