one and two dimensional contaminant transport by pure diffusion through single layer of fine grained soil was investigated using one and two dimensional laboratory models. these models simulates a simple hydrogeologic situation underneath a solid waste landfill comprising a fine grained soil overlying a bed rock. sodium chloride solution was sued as a contaminant source above a compacted clayey...

UNLABELLED To protect occupants from infectious diseases or possible chemical/biological agents released by a terrorist in an enclosed space, such as an airliner cabin, it is critical to identify gaseous contaminant source locations and strengths. This paper identified the source locations and strengths by solving inverse contaminant transport with the quasi-reversibility (QR) and pseudo-revers...

While the discussion of model uncertainty has centered on spatial heterogeneity, it is possible that ground water models have not enjoyed much success as predictive tools often because the sources that were eventually imposed in the field differed from those represented in the simulations. This is because deterministic prediction of future conditions is often inaccurate due to the random nature...

Introduction It is recognized that physical and chemical interactions between adjacent ground water and surface water bodies are an important factor impacting water budget and nutrient/ contaminant transport within a watershed (Winter et al., 1998). This observation is also of importance for hazardous waste site cleanup within the United States, since about 75% of sites regulated under the Reso...

Advection flow is a dominating physical mechanism of contaminant transport over geologic fractured media. Natural fractures often combine into percolation cluster, having fractal properties. As a result long-ranged correlations arise in the fluctuating velocity field of infiltration flux. The presence of preferred direction due to the gravity force leads to the strong anisotropy of the advectio...

A mathematical method called subordination broadens the applicability of the classical advection--dispersion equation for contaminant transport. In this method, the time variable is randomized to represent the operational time experienced by different particles. In a highly heterogeneous aquifer, the operational time captures the fractal properties of the medium. This leads to a simple, parsimo...

The ability to directly characterize chemical transport and interactions that occur within a material (i.e., subsurface dynamics) is a vital component in understanding contaminant mass transport and the ability to decontaminate materials. If a material is contaminated, over time, the transport of highly toxic chemicals (such as chemical warfare agent species) out of the material can result in v...