title: Reinterpreting literature sorption data considering both absorption into organic carbon and adsorption onto black carbon.
abstract: We hypothesized that the sorption of polycyclic aromatic hydrocarbons (PAHs) to natural sediments and soils should consider both absorption into a biogenic/diagenetic organic carbon (OC) fraction and adsorption onto a combustion-derived, black carbon (BC) fraction. Here, two sets of literature data were reevaluated to illustrate that an OC absorbent and a BC adsorbenttogether can (1) account for sediment--pore-waterdistribution coefficients observed in the field that are greater than predicted by a simple f(OC)K(OC) partitioning model and (2) explain a group of nonlinear phenanthrene isotherms observed in the laboratory with a single value for the BC-normalized distribution coefficient (log K(BC) = 6.1 i 0.04) and a Freundlich exponent (n approximately 0.6 if log K(OC) = 4.0) that is strongly dependent on the K(OC) value selected.
authors.affiliation: Ralph M. Parsons Laboratory, MIT 48-415, Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: Amymarie
authors.initials: A
authors.lastname: Accardi-Dey
authors.forename: Philip M
authors.initials: PM
authors.lastname: Gschwend
mesh_terms: D000042:Absorption; D002244:Carbon / Q000737:chemistry*; D004785:Environmental Pollutants / Q000032:analysis; D019015:Geologic Sediments / Q000737:chemistry; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry*; D016062:Porosity
chemical_list: D004785:Environmental Pollutants; D011084:Polycyclic Aromatic Hydrocarbons; D002244:Carbon