Analysis of adsorption equilibrium of volatile chlorinated organic compounds to dry soil.

Adsorption is one of the main mechanisms of soil contamination by hazardous volatile chlorinated organic compounds. The adsorption equilibriums of six volatile organic chlorinated compounds to three dry soils were investigated using batch adsorption experiments. The adsorption equilibriums for the dry soils could be expressed by the Dubinin-Astakhov equation. The equation's parameters were analyzed with the characteristic values of the soils and compounds. No correlation between the values of the affinity coefficients, beta, and the molecular volume, Mv, was found. W(0) could be expressed by the functions of a pore volume of less than 10 nm, V(<10 nm), or the specific surface area, S. The adsorbed amount could be estimated using equations relating E(0), V(<10 nm) (or S), and beta. The predicted amounts agreed well with the measured data.