Sorption of Dibenzothiophene by Soils and Sediments

The effect of sediment and soil properties on adsorption of dibenzothiophene, a potential carcinogenic and/or mutagenic compound, was examined. Sorption isotherms were determined on soil and sediments collected from the Ohio, Missouri, Mississippi, and Illinois rivers and their watersheds. The sorption isotherms were approximately linear over the entire concentration range studied. The linear adsorption or partition coefficient was significantly correlated with the organic carbon contents of the soils and sediments. The other factors tested (e.g., total clay, clay mineralology, CEC, surface area, pH) were nonsignificant. The Koc value estimated from the octanol‐water partition coefficient (Kow) was in good agreement with the Koc value of 11,230 determined experimentally. The sorption of dibenzothiophene as a result of a weak solute‐solvent interaction rather than a strong sorbate‐sorbent interaction is discussed.