title: Impact of soil amendments and the plant rhizosphere on PAH behaviour in soil.
abstract: Carbonaceous amendments reduce PAH dissolved concentrations (Cfree), limiting their uptake and toxicity. A soil contaminated with PAHs was mixed with activated carbon (AC), charcoal or compost and planted with radish (Raphanus sativus L.), and Cfree, chemical activities and diffusive uptake of the PAHs measured over 2 months. For AC, Cfree and diffusive uptake were decreased by up to 94% compared to the unamended soil within one week. In addition, the sum chemical activity of the PAHs remained below the threshold for baseline toxicity. In contrast, charcoal and compost only led to modest reductions in Cfree and diffusive uptake, with sum chemical activities that could potentially result in baseline toxicity being observed. Furthermore, both Cfree and diffusive uptake were lower in the planted compared to unplanted soils. Therefore, only AC successfully reduced PAH acute toxicity in the soil, but plant-promoted microbial degradation may also play an important role in PAH attenuation.
authors.affiliation: Center for Energy Resources Engineering, Technical University of Denmark, Søltofts Plads Building 229, 2800 Lyngby, Denmark.
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Marchal
authors.affiliation: Korean Institute of Science and Technology Europe, Campus E7.1, Universität des Saarlandes, 66123 Saarbrücken, Germany.
authors.forename: Kilian E C
authors.initials: KE
authors.lastname: Smith
authors.affiliation: Department of Environmental Engineering, Technical University of Denmark, Miljøvej Building 113, 2800 Kgs. Lyngby, Denmark.
authors.forename: Philipp
authors.initials: P
authors.lastname: Mayer
authors.affiliation: Aarhus University, Department of Agroecology, Blichers Allé, Postbox 50, DK 8830 Tjele, Denmark.
authors.forename: Lis
authors.initials: L
authors.lastname: Wollesen de Jonge
authors.affiliation: Department of Environmental Science, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark. Electronic address: uka@dmu.dk.
authors.forename: Ulrich G
authors.initials: UG
authors.lastname: Karlson
mesh_terms: D002606:Charcoal / Q000737:chemistry; D052918:Environmental Restoration and Remediation / Q000379:methods*; D008956:Models, Chemical; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis* / Q000737:chemistry; D031224:Raphanus / Q000502:physiology; D058441:Rhizosphere; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis* / Q000737:chemistry
chemical_list: D011084:Polycyclic Aromatic Hydrocarbons; D012987:Soil; D012989:Soil Pollutants; D002606:Charcoal
keywords: Chemical activity; Diffusive uptake; Freely dissolved concentration; Passive sampling; Radish (Raphanus sativus L.)