Vapor phase adsorption-desorption of 1,1,1-trichloroethane on dry soil

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:250924

Dural, N H ^[1]; Chen, C H ^[2]

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1. Cleveland State Univ., OH (United States). Dept. of Chemical Engineering
2. Univ. of Missouri, Columbia, MO (United States). Dept. of Chemical Engineering

Vapor phase adsorption of 1,1,1-trichloroethane (TCA) on dry soils was studied at 288, 293, and 298 K. Using a gravimetric adsorption apparatus adsorption/desorption isotherms of TCA were generated on two representing soil samples with different physical/chemical characteristics. Influence of temperature and soil properties were investigated. Isosteric heats of adsorption were calculated and heat curves were established. The experimental data were correlated by the Polanyi Potential, the BET, and the GAB models. Equilibrium isotherms of TCA on both soils were Type 2, characterizing vapor condensation to form multilayers, and they exhibited hysteresis upon desorption. A positive correlation between the soil`s specific surface area and its sorption capacity was observed. Clay content and pore size were also dominating factors. Thermal data showed that the adsorption of TCA vapor on soil was primarily due to physical forces and both samples exhibited energetically heterogeneous surfaces. Results followed the Potential Theory satisfactorily and led to a single temperature-independent characteristic curve for each soil-TCA pair. The BET equation gave accurate correlations for up to 40 % of the saturation pressure, while the GAB equation provided superior correlation of the data for the entire relative pressure range.

• OSTI ID: 250924
• Report Number(s): CONF-9507204--
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
ADSORPTION ISOTHERMS
CHLORINATED ALIPHATIC HYDROCARBONS
REMEDIAL ACTION
REMOVAL
SOILS
VAPORS
WASTE PROCESSING