FUNDAMENTALS FOR THE THERMAL REMEDIATION OF CONTAMINATED SOILS - PARTICLE AND BED DESORPTION MODELS

A major research effort has been initiated to characterize the rate-controlling processes associated with the evolution of hazardous materials from soils. A 3-fold experimental approach was used in conjunction with computer modeling to analyze thermal desorption of contaminants. Phenomena occurring both inside particles (intraparticle) and within a bed of particles (interparticle) were studied. The results obtained suggest that the most important process variables are local thermal environment and gas-phase contaminant concentration because the adsorption equilibrium characteristics of the contaminant/soil pair control the desorption of contaminant from a particle at a given temperature. A mass-transfer/desorption model, which assumes gas/solid equilibrium at all points and time, is proposed and the model was found to predict the measured temperature dependence. © 1990, American Chemical Society. All rights reserved.