title: Characterising the exchangeability of phenanthrene associated with naturally occurring soil colloids using an isotopic dilution technique.
abstract: The association of polycyclic aromatic hydrocarbons (PAHs) with inorganic and organic colloids is an important factor influencing their bioavailability, mobility and degradation in the environment. Despite this, our understanding of the exchangeability and potential bioavailability of PAHs associated with colloids is limited. The objective of this study was to use phenanthrene as a model PAH compound and develop a technique using (14)C phenanthrene to quantify the isotopically exchangeable and non-exchangeable forms of phenanthrene in filtered soil water or sodium tetraborate extracts. The study was also designed to investigate the exchangeability of colloidal phenanthrene as a function of particle size. Our findings suggest that the exchangeability of phenanthrene in sodium tetraborate is controlled by both inorganic and organic colloids, while in aqueous solutions inorganic colloids play the dominant role (even though coating of these by organic matter cannot be excluded). Filter pore size did not have a significant effect on phenanthrene exchangeability.
authors.affiliation: Centre for Environmental Risk Assessment and Remediation, University of South Australia, Building X, Mawson Lakes Campus, South Australia 5095, Australia; NSW Department of Primary Industries, Wagga Wagga Agricultural Institute, PMB Pine Gully Rd, Wagga Wagga 2650, Australia. Electronic address: ehsan.tavakkoli@dpi.nsw.gov.au.
authors.forename: Ehsan
authors.initials: E
authors.lastname: Tavakkoli
authors.affiliation: Centre for Environmental Risk Assessment and Remediation, University of South Australia, Building X, Mawson Lakes Campus, South Australia 5095, Australia.
authors.forename: Albert
authors.initials: A
authors.lastname: Juhasz
authors.affiliation: Centre for Environmental Risk Assessment and Remediation, University of South Australia, Building X, Mawson Lakes Campus, South Australia 5095, Australia.
authors.forename: Erica
authors.initials: E
authors.lastname: Donner
authors.affiliation: Centre for Environmental Risk Assessment and Remediation, University of South Australia, Building X, Mawson Lakes Campus, South Australia 5095, Australia.
authors.forename: Enzo
authors.initials: E
authors.lastname: Lombi
mesh_terms: D003102:Colloids / Q000032:analysis*; D004784:Environmental Monitoring; D007201:Indicator Dilution Techniques; D008956:Models, Chemical; D010616:Phenanthrenes / Q000032:analysis*; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis*
chemical_list: D003102:Colloids; D010616:Phenanthrenes; D011084:Polycyclic Aromatic Hydrocarbons; D012987:Soil; D012989:Soil Pollutants; C031181:phenanthrene
keywords: Colloids; E-value; Exchangeability; Isotopic dilution technique; PAHs; Phenanthrene