SOIL CLEANUP BY IN-SITU AERATION .22. IMPACT OF NATURAL SOIL ORGANIC-MATTER ON CLEANUP RATES

A mathematical model for soil vapor extraction of volatile organic com pounds from soils rich in natural humic organic carbon by means of a s ingle vertical well screened along its length and operating underneath an impermeable cap is described. The model includes a distributed dif fusion treatment of diffusion kinetics. Partitioning of volatile organ ic compounds between the aqueous phase and the natural organic carbon is handled by a linear isotherm or by a Freundlich isotherm. Freundlic h isotherm exponents n(f) chosen on the basis of published data lead t o substantially more prolonged remediations than result from use of a similar linear isotherm.