Sorption of 2,3,7,8-tetrachlorodibenzo-p-dioxin to soils from water/methanol mixtures

Journal Article · Fri Jul 01 04:00:00 EDT 1988 · Environ. Sci. Technol.; (United States)

DOI:https://doi.org/10.1021/es00172a012· OSTI ID:6870618

Walters, R W; Guiseppi-Elle, A

Sorption of /sup 14/C-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 (f/sub s/) was varied between 0.25 and 1.0. Sorption kinetics were influenced by soil type and f/sub s/; at f/sub s/ 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. For f/sub s/ of 1.0 and the high-f/sub oc/ soil, sorption equilibrium was attained in about 10 days. Sorption isotherms were linear, and when sorption partition coefficients (K/sub D/, mL/g) were converted to K/sub m/ (mol/g), these latter values were log-linearly related to f/sub s/. K/sub m/ values for two soils, when normalized on f/sub oc/, gave values of K/sub m,oc/ that collapsed onto a single line having the equation determined by linear regression analysis: log K/sub m,oc/ = -4.97f/sub s/ + 5.30 with r/sup 2/ = 0.98 and s = 0.20. log K/sub oc/, the logarithm of the aqueous-phase partition coefficient normalized on f/sub oc/, for TCDD extrapolated from this relationship is 6.6 +/- 0.7. The slope of the log-linear relationship is related to the effect of f/sub s/ on TCDD solubility and on TCDD-soil and solvent-soil interactions.

• Research Organization: Univ. of Maryland, College Park (USA)
• OSTI ID: 6870618
• Journal Information: Environ. Sci. Technol.; (United States), Journal Name: Environ. Sci. Technol.; (United States) Vol. 22:7; ISSN ESTHA
• Country of Publication: United States
• Language: English

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54 ENVIRONMENTAL SCIENCES
ALCOHOLS
CARBON 14 COMPOUNDS
CHEMISTRY
CONTAMINATION
DIOXIN
DISPERSIONS
FEDERAL REGION VII
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
METHANOL
MISSOURI
MIXTURES
NORTH AMERICA
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
SOIL CHEMISTRY
SOILS
SORPTION
TRACER TECHNIQUES
USA