Diffusion and adsorption of benzene in Regina clay

Abstract

The diffusion and adsorption coefficients for benzene were measured for a glaciolacustrine clay using the single- and double-reservoir methods, batch tests, and organic carbon content correlations. Single- and double-reservoir diffusion test cells and experimental procedures were specifically developed for volatile organic chemicals. Analytical methods based on solvent extraction with gas chromatography - flame ionization detection and purge and trap gas chromatography - mass spectrometry were used for the analysis of aqueous benzene solutions in the 0.5 µg/L to 500 mg/L range. The measured effective diffusion coefficient was 0.01 m2/a (3.2 × 10-6 cm2/s), and adsorption coefficients ranged from 0.1 to 1.0 mL/g. The diffusion cell tests indicate relatively low levels of retardation for benzene as it moves in clay soils with low organic carbon content.Key words: adsorption, diffusion, benzene, Regina clay.