title: Sorption determination of phenols and polycyclic aromatic hydrocarbons in a multiphase constructed wetland system by solid phase microextraction.
abstract: Non-degradative sorption of organic pollutants onto plant roots during phytoremediation is an essential retardation mechanism. To determine the extent of the attenuation processes the freely dissolved concentrations of organic solutes must be determined rather than their total concentrations. Thus, the assessment of attenuation caused by sorption onto plant compartments can be biased when using traditional methods. This bias holds especially true in cases of complex multiphase systems characterized by high concentrations of dissolved and suspended organic matter, both of them contributing to a reduction in concentration of the free solutes. A relatively new approach based on solid phase microextraction (SPME) circumvents these obstacles. SPME measures the true freely dissolved concentration of organic solutes without affecting the sorption equilibrium, thus allowing non-biased conclusions about ecotoxicological hazards of organic sorbates. Herein, sorption of phenols (including alkylated phenols) along with polycyclic aromatic hydrocarbons (PAHs) onto roots of Juncus effusus was investigated. Sorption coefficients in the complex system measured with SPME were significantly higher compared to those measured by traditional methods such as phase separation and solvent extraction. A concept based on Hildebrand solubility parameters was applied to interpret and predict sorption onto helophyte roots. The solubility parameter of the root sorbent was calculated as 26.1 (Jcm(-3))(0.5), which is between that of lignin and cellulose/hemicellulose.
authors.affiliation: UFZ-Helmholtz Center for Environmental Research, Department of Environmental Engineering, Permoserstr. 15, D-04318 Leipzig, Germany. Electronic address: juergen.poerschmann@ufz.de.
authors.forename: Juergen
authors.initials: J
authors.lastname: Poerschmann
authors.affiliation: UFZ-Helmholtz Center for Environmental Research, Department of Environmental Biotechnology, Germany.
authors.forename: Luciana
authors.initials: L
authors.lastname: Schultze-Nobre
mesh_terms: D000327:Adsorption; D004784:Environmental Monitoring; D010636:Phenols / Q000032:analysis / Q000737:chemistry*; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis / Q000737:chemistry*; D052617:Solid Phase Microextraction; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*; D053833:Wetlands
chemical_list: D010636:Phenols; D011084:Polycyclic Aromatic Hydrocarbons; D014874:Water Pollutants, Chemical
keywords: Phenols; Phytoremediation; Polycyclic aromatic hydrocarbons; Root uptake; Solubility concept