In situ hazardous waste site remediation techniques
Three in situ hazardous waste site remediation techniques are investigated: Soil vapor extraction (SVE), soil flushing and groundwater air sparging. A computer model for simulation of the SVE technique is modified to include a random air permeability function. This random function allows a more realistic representation of the permeability type at many sites. Randomness in the permeability is introduced via random phases in a Fourier series. The effect of two user-defined parameters, included in the amplitude term, on the distribution of the permeability function is explored. Multiple iterations of the model define a range of probable clean-up times. The equilibrium partitioning of various polycyclic aromatic hydrocarbons (anthracene, phenanthrene, naphthalene and acenaphthene) between water and soil is investigated to provide information regarding the efficacy of soil flushing for treatment of soils contaminated with these compounds. The relative strength of binding of the organics to the soil provides a measure of the ability of a particular solvent to mobilize the contaminant. An attempt is made to characterize the adsorption isotherms. The isotherms may be used in computer simulations of the remediation technique. A method is developed for the study of the adsorption/desorption isotherms. A computer simulation is conducted for the treatment of groundwater contaminated with dense nonaqueous phase liquids (DNAPLs) by groundwater air sparging. Mass transport and volatilization of the aqueous phase of the organic compound is simulated, as well as diffusion of the DNAPL from porous spheres into the dissolved phase. The effect of various factors (the concentration of the dissolved and bulk phases, diffusivity, radius of the porous spheres, air flow rate, water flow rate and Henry's constant) on the calculated clean-up time is studied. A method is proposed whereby the clean-up time may be estimated after only a limited number of model time steps.
- Research Organization:
- Vanderbilt Univ., Nashville, TN (United States)
- OSTI ID:
- 7113393
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
400105 -- Separation Procedures
54 ENVIRONMENTAL SCIENCES
540120* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (1990-)
COMPUTERIZED SIMULATION
CONTROL
GROUND WATER
HAZARDOUS MATERIALS
HYDROGEN COMPOUNDS
IN-SITU PROCESSING
LAND POLLUTION CONTROL
MATERIALS
OXYGEN COMPOUNDS
POLLUTION CONTROL
PROCESSING
REMEDIAL ACTION
SEPARATION PROCESSES
SIMULATION
SOILS
WATER