Sorption of hydrophobic compounds on aquifer materials: analysis methods and the effect of organic carbon

Sorption studies of polynuclear aromatic hydrocarbons (PAH) on low-carbon aquifer materials are reported. Both column and batch partition coefficients ( K d) were affected by synthetic polymeric components, such as Teflon®, in commonly used experimental apparatus. These influences include incorrect (high) estimates for K d and tailing of peaks in column studies. Both batch and column experimental methods are developed, using polymer-free systems, that allow accurate measurement of K d's for hydrophobic PAHs in low-carbon systems. Application of these methods shows that organic carbon contents below the commonly cited threshold level of 0.1% may dominate the partitioning and subsequent transport of phenanthrene in aquifer systems.