SORPTION OF 2,3,7,8-TETRACHLORODIBENZO-PARA-DIOXIN TO SOILS FROM WATER-METHANOL MIXTURES

Sorption of **1**4C-labeled 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) to soils from water/methanol mixtures has been evaluated by batch shake testing. Uncontaminated soils from Times Beach, MO, were used in these experiments and ranged in fraction organic carbon (f//o//c) from 0. 0066 to 0. 077. Volume fraction methanol in the liquid phase (f//s) was varied between 0. 25 and 1. 0. Contact times ranging from 1 to 90 days were employed. Sorption kinetics were influenced by soil type and f//s. Sorption isotherms were linear, and when sorption partition coefficients (K//D, mL/g) were converted to K//m (mol/g), these latter values were log-linearly related to f//s. Study results are discussed.