Send to

Choose Destination
See comment in PubMed Commons below
Environ Sci Technol. 2007 May 1;41(9):3254-61.

Modeling sorption of anionic surfactants onto sediment materials: an a priori approach for perfluoroalkyl surfactants and linear alkylbenzene sulfonates.

Author information

  • 1Department of Civil and Environmental Engineering, Stanford University, Stanford, California 94305-4020, USA.

Erratum in

  • Environ Sci Technol. 2007 Sep 1;41(17):6316.


A mechanistically derived model predicting the sorption of anionic surfactants to sediments was developed and evaluated for three classes of surfactants: perfluoroalkyl carboxylates, perfluoroalkyl sulfonates, and linear alkylbenzene sulfonates. The model includes both hydrophobic and electrostatic components and estimates the contribution of each to the sediment-water distribution coefficient (Kd) using Gibbs free energy terms. The hydrophobic free energy term was calculated from the aqueous solubilities of non-charged alkylbenzene or perfluoroalkane analogs and prior observations of increases in Kd values with increasing chain lengths. The electrostatic term was calculated from aqueous solution measurements using the non-ideal competitive adsorption Donnan (NICA-Donnan) model. The NICA-Donnan calculations were performed using parameters previously derived for generic humic acids. These two terms were coupled by multiplying by the fraction of organic carbon in the sediment, foc, and a single fitting parameter, Faccess, the volumetric fraction of organic carbon accessible to the sorbing surfactant. The combined model accurately predicted the sediment-water distribution coefficients for all three classes of anionic surfactants. In its current formulation, the model was unable to capture the slight degree of isotherm nonlinearity observed for these surfactants.

[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Loading ...
    Support Center