A finite-difference algorithm used to simulate one-dimensional diffusion and adsorption of trichloroethene in a rock matrix
Dates
Release Date
2018-01-01
Time Period
2018
Publication Date
2023-09-15
Citation
Shapiro, A.M., 2018, A finite-difference algorithm used to simulate one-dimensional diffusion and adsorption of trichloroethene in a rock matrix: U.S. Geological Survey data release, https://doi.org/10.5066/P963WPSO.
Summary
Simulations of one-dimensional (1-D) diffusion and adsorption of trichloroethene (TCE) in a rock matrix are conducted using rock properties identified from a mudstone aquifer in the Newark Basin, near West Trenton, New Jersey. The simulations are conducted using a finite-difference algorithm that was prepared for this investigation to solve the equation for 1-D diffusion and linear equilibrium adsorption. The simulations are conducted for a hypothesized 1-D section of a rock matrix and the georeferencing is based on the locations of the rock core samples that were collected and analyzed as part of this investigation. The rock matrix is assumed to be adjacent to a fracture, where the TCE concentration in the fracture is responsible [...]
Summary
Simulations of one-dimensional (1-D) diffusion and adsorption of trichloroethene (TCE) in a rock matrix are conducted using rock properties identified from a mudstone aquifer in the Newark Basin, near West Trenton, New Jersey. The simulations are conducted using a finite-difference algorithm that was prepared for this investigation to solve the equation for 1-D diffusion and linear equilibrium adsorption. The simulations are conducted for a hypothesized 1-D section of a rock matrix and the georeferencing is based on the locations of the rock core samples that were collected and analyzed as part of this investigation. The rock matrix is assumed to be adjacent to a fracture, where the TCE concentration in the fracture is responsible for diffusion into and out of the rock matrix. The fraction of organic carbon (foc) in the rock matrix can either be spatially uniform or spatially variable. Spatial variability in foc is defined from the mean and standard deviation of a log-normally distributed parameter. Other rock properties controlling the diffusion and adsorption of TCE in the rock matrix are assumed to be spatially uniform. Simulations of diffusion and adsorption into the rock matrix are conducted for four cases. These cases are: (1) spatially uniform foc equal to the average of foc from all rock samples; (2) spatially uniform foc equal to the maximum foc from all rock samples; (3) spatially uniform foc equal to the average foc from the Black Fissile (BLK-FIS) mudstone samples; (4) spatially variable foc defined from the statistics of the BLK-FIS mudstone samples. This USGS data release contains all of the input and output files for the simulations described in the associated journal article (https://doi.org/10.1016/j.jconhyd.2018.09.001).
The simulations were conducted to investigate the effect of the spatial variability of foc on the retention and release of TCE in a rock matrix. Simulations using spatially variable and spatially uniform foc are conducted to compare the effect of spatial variability in foc on the longevity of TCE remaining in the rock matrix. The development of the model input and output files included in this data release are documented in the article published in the Journal of Contaminant Hydrology (https://doi.org/10.1016/j.jconhyd.2018.09.001).
Preview Image
Image of the model domain and active area of the model.