Document Type
Thesis
Date of Award
5-31-1987
Degree Name
Master of Science in Environmental Engineering - (M.S.)
Department
Civil and Environmental Engineering
First Advisor
Joseph W. Bozzelli
Second Advisor
Theodore Petroulas
Third Advisor
Samir S. Sofer
Abstract
The purpose of this initial laboratory scale research project was to study and demonstrate the feasibility in removal of selected toxic organic compounds from soil by thermal desorption and gas purge. Applying heat and a flow of inert gas to the soil increases the volatilization and effects removal of organic compounds from soil. The work was done in two parts: First, organic solvents were injected into columns containing real and simulated soil matrices. The columns were heated to one of the four temperatures and purged with a flow of nitrogen carrier gas. The organic vapors were deposited as a plug on the front of the column. The rate of passage (adsorption/desorption) of the plug through the various soil matrices was measured by a gas chromatograph equipped with a flame ionization detector (FID). The process was mathematically modeled and can be used to predict behavior such as effusion rates and transport of these compounds in soil desorption systems.
Second, a desorption system was constructed which utilized a uniformly contaminated soil column, purge flow controls, a desorption oven, valve switching system and a gas chromatograph. Columns containing soils contaminated with known concentrations of 1,2,4-trichlorobenzene and hexachlorobenzene were placed into the oven which was heated to one of four temperatures studied. A known nitrogen gas flow desorbed the compounds from the soil and into a switching valve. Vapors were directed either to a GC column and FID for analysis, or to an activated carbon adsorber for collection. Solvent extractions of the soil samples and adsorbers columns provided a mass balance through the system. Analysis of pollutant quantities in the vapor stream entering the FID as a function of purge time and oven temperature allowed the rate of desorption to be measured. Mathematical models were developed and curves plotted that represented the rate of desorption of the compounds from the soil. The results lead to suggestions in the design of a pilot plant scale thermal desorption system.
Recommended Citation
Hornsby, Michael L., "Thermal desorption of hazardous and toxic organic compounds from soil matrices" (1987). Theses. 3110.
https://digitalcommons.njit.edu/theses/3110
