ABSTRACT
Hydrophobic organic compounds (HOCs) can interact with natural particles such as soils or sediments [1-19] and be removed from aqueous solution. These sorption interactions may result in strong binding and greatly affect the toxicity, transport, and fate of contaminants such as polycyclic aromatic hydrocarbons (PAHs) [16,20-22]. Soil or sediment organic matter (SOM) and their mineral matrices have very different contributions to the sorption. For HOCs, the adsorption on wet minerals is strongly suppressed by competition from water [4,16] and SOM becomes the dominant sorption medium. However, the complexity and heterogeneity of SOM represent a real challenge for the identification of molecular-scale sorption mechanisms [16]. Though the sorption/adsorption of HOCs in/on SOM has been extensively studied, the specific role of the different SOM fractions is still mostly unknown.
