Soil clean up by in-situ aeration. VII. High-speed modeling of diffusion kinetics

Journal Article · Mon Dec 31 23:00:00 EST 1990 · Separation Science and Technology; (United States)

DOI:https://doi.org/10.1080/01496399108050494· OSTI ID:5325478

Rodriguez-Maroto, J M ^[1]; Wilson, D J ^[2]

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1. Univ. de Malaga (Spain)
2. Vanderbilt Univ., Nashville, TN (USA)

A mathematical model for soil vacuum extraction is developed which allows the modeling of vapor stripping from media of highly heterogeneous permeability, in which one may not be able to make the assumption of local equilibrium between the stationary phase(s) and the moving vapor phase with respect to volatile organic compound (VOC) transport. A lumped parameter approximation is used to deal with the kinetics of diffusion (and/or desorption) of the VOC from the interiors of lumps of clay or porous bedrock out into the advecting soil gas. This model, which makes the steady-state approximation for the VOC vapor concentrations, typically uses less than one-twentieth the computer time of an earlier nonsteady-state model and gives results which are in excellent agreement with that model. This model also yields results which are in agreement with a local equilibrium model if the rate constant for diffusion/desorption is large. The effects of impermeable caps and passive vent wells decrease as the rate of diffusion/desorption is decreased.

• OSTI ID: 5325478
• Journal Information: Separation Science and Technology; (United States), Journal Name: Separation Science and Technology; (United States) Vol. 26:6; ISSN SSTED; ISSN 0149-6395
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540250* -- Environment
Terrestrial-- Site Resource & Use Studies-- (1990-)
AERATION
CLAYS
CLEANING
COMPUTER CALCULATIONS
DECONTAMINATION
DESORPTION
DIFFUSION
EQUATIONS
EQUILIBRIUM
EVAPORATION
FLOW RATE
FLUID FLOW
GAS FLOW
HAZARDOUS MATERIALS
HAZARDOUS MATERIALS SPILLS
KINETICS
LAND RECLAMATION
LEAKS
MASS TRANSFER
MATERIALS
MATHEMATICAL MODELS
MATTER
ONE-DIMENSIONAL CALCULATIONS
ORGANIC COMPOUNDS
PERMEABILITY
PHASE TRANSFORMATIONS
POROUS MATERIALS
SOILS
STORAGE
TIME DEPENDENCE
TWO-DIMENSIONAL CALCULATIONS
UNDERGROUND STORAGE
VACUUM EVAPORATION
VOLATILE MATTER
WELLS