Document Type
Thesis
Date of Award
12-31-1988
Degree Name
Master of Science in Civil Engineering - (M.S.)
Department
Civil and Environmental Engineering
First Advisor
Su Ling Cheng
Second Advisor
John W. Liskowitz
Third Advisor
Paul C. Chan
Abstract
An experimental investigation on the desorption of contaminated clay soils by thermal treatment was performed. This study was carried out on two clay soils (kaolinite and bentonite) sorbed with three liquid organic compounds (phenol, chlorophenol, and chlorobenzene). The study consists of two different phases, the adsorption and desorption. The results on batch equilibrium adsorption were correlated with different isotherm models of which the Freundlich isotherm model was found to be best fit in predicting adsorption capacities of kaolinite, and that for bentonite was found to be the linear isotherm model.
A thermal desorption study followed the equilibrium adsorption study. A thermogravimetric analyzer (TGA), was connected to a gas chromatograph (GC) through an interface unit (which consists of a sampling loop and a six-port valve) for the thermal desorption experiments. These experiments were performed for different final temperatures and purge gas flow rates.
The degree of decontamination was found to be affected by the initial concentration (i.e., lower the concentration of the adsorbate, lower the percentage of organic removed from soil). In addition, the results indicate that bentonite requires a higher purge gas rate compared to that of kaolinite, in order to ascertain the same level of thermal desorption. This variation was due to the less interconnected pores and high plasticity in bentonite, creating a potential barrier for the flow of purge gas through the sample, resulting in lower thermal desorption compared to that of kaolinite.
Furthermore, it was found that a temperature of 450°C is the optimum and most economical for "clean up" of soils contaminated with the above liquid organic pollutants.
Recommended Citation
Weerasinghe, Chandrakanthi, "Decontamination of contaminated clay soils by thermal treatment" (1988). Theses. 3246.
https://digitalcommons.njit.edu/theses/3246
