title: Binding of polycyclic aromatic hydrocarbons by humic acids formed during composting.
abstract: Binding of two model polycyclic aromatic hydrocarbons (PAHs), phenanthrene and pyrene, by humic acids (HAs) isolated from an organic substrate at different stages of composting and a soil was investigated using a batch fluorescence quenching method and the modified Freundlich model. With respect to soil HA, the organic substrate HA fractions were characterized by larger binding affinities for both phenanthrene and pyrene. Further, isotherm deviation from linearity was larger for soil HA than for organic substrate HAs, indicating a larger heterogeneity of binding sites in the former. The composting process decreased the binding affinity and increased the heterogeneity of binding sites of HAs. The changes undergone by the HA fraction during composting may be expected to contribute to facilitate microbial accessibility to PAHs. The results obtained also suggest that bioremediation of PAH-contaminated soils with matured compost, rather than with fresh organic amendments, may result in faster and more effective cleanup.
authors.affiliation: Centro de Ciencias Medioambientales, Consejo Superior de Investigaciones Científicas, Serrano 115 dpdo., 28006 Madrid, Spain. c.plaza@ccma.csic.es
authors.forename: César
authors.initials: C
authors.lastname: Plaza
authors.forename: Baoshan
authors.initials: B
authors.lastname: Xing
authors.forename: José M
authors.initials: JM
authors.lastname: Fernández
authors.forename: Nicola
authors.initials: N
authors.lastname: Senesi
authors.forename: Alfredo
authors.initials: A
authors.lastname: Polo
mesh_terms: D001673:Biodegradation, Environmental; D006812:Humic Substances / Q000032:analysis*; D010616:Phenanthrenes / Q000737:chemistry; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry*; D011721:Pyrenes / Q000737:chemistry; D012987:Soil; D012989:Soil Pollutants / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
chemical_list: D006812:Humic Substances; D010616:Phenanthrenes; D011084:Polycyclic Aromatic Hydrocarbons; D011721:Pyrenes; D012987:Soil; D012989:Soil Pollutants; C031181:phenanthrene; C030984:pyrene