Accession Number : ADA300827

Title :   Pore Structure Model for Water and Contaminant Transport in Soil.

Descriptive Note : Interim rept. 28 Sep 94-27 Sep 95,

Corporate Author : SIMONS RESEARCH ASSOCIATES LYNNFIELD MA

Personal Author(s) : Simons, Girard A.

PDF Url : ADA300827

Report Date : 27 SEP 1995

Pagination or Media Count : 25

Abstract : The pore tree model of pore structure was developed for catalyst and sorbent grains to allow coupled reactions and diffusion into and out of immobile porous media in the absence of convection through the media. The pore tree model is extended herein to describe the permeable (mobile) pore structure which characterizes the subsurface transport of gas and water in soil, the dispersion of contaminants, and in-situ remediation. The interconnectivity of the pore structure is obtained via a statistical determination of the branches that are common to several trees to allow convection and diffusion through the large scale (mobile) structure in addition to diffusion and reactions in the small scale (immobile) structure. The extended pore tree model has explained the measurement errors in the permeability of soil due to the measurement scale size and has successfully predicted the bulk gaseous diffusivity in partially saturated soil as a function of a saturation scale size. The theory also depicts a permeable sub-range in which small scale convection bridges the flow between the bulk convection and the small scale diffusion.

Descriptors :   *SOIL POLLUTION, *SOIL CHEMISTRY, MATHEMATICAL MODELS, COUPLING(INTERACTION), PERMEABILITY, CHEMICAL CONTAMINATION, CONVECTION, SAND, SATURATED SOILS, TRANSPORT PROPERTIES, CATALYSTS, DIFFUSION, PORE PRESSURE, SUBSURFACE, GAS SURFACE INTERACTIONS, POROUS MATERIALS.

Subject Categories : Soil Mechanics
      Physical Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE