Sorption of 2,3,7,8-Tetrachlorodibenzo-p-dioxin to Soils from Water/Methanol Mixtures

摘要

Sorption of 14C-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(sub oc) from 0.0066 to 0.077. Volume fraction methanol in the liquid phase (fs) 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 fs; at fs of 0.5, sorption equilibrium for low-f(sub oc) soils was achieved within 1 day, while sorption to the high-f(sub oc) soil required as long as 30 days to reach equilibrium. Data presented here suggest that the latter solvent-soil interactions may not increase TCDD accessibility to soil organic matter to the same extent as that reported for less hydrophobic organic solutes. (Copyright (c) 1988 American Chemical Society.)