title: Composition and structure of agents responsible for development of water repellency in soils following oil contamination.
abstract: Soil from the Ellerslie site of experimental oil contamination in Alberta developed water repellency some years after initial remediation. The water-repellent soils were compared to clean soils and contaminated but wettable soils by solid-state nuclear magnetic resonance (NMR). The effects of extraction with CH2Cl2 (for petroleum hydrocarbons), NaOH (for natural organic matter), and 2-propanol/ammonia (IPA/NH3) on wettability were evaluated by the molarity of the ethanol droplet (MED) test. Soil extracts and whole soils, after extraction, were examined using NMR and Fourier transform infrared spectroscopy (FTIR). On the basis of the structure--MED correlations, a model of a thin-layer natural organic matter--petroleum products complex formed under strong drying conditions is proposed to account for the development of water repellency. Studies of two similar soils from accidental oil spills are supportive.
authors.affiliation: Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, Alberta, Canada T2N 1N4.
authors.forename: Marina
authors.initials: M
authors.lastname: Litvina
authors.forename: Tiona R
authors.initials: TR
authors.lastname: Todoruk
authors.forename: Cooper H
authors.initials: CH
authors.lastname: Langford
mesh_terms: D004787:Environmental Pollution / Q000517:prevention & control*; D009682:Magnetic Resonance Spectroscopy; D010578:Petroleum; D012989:Soil Pollutants / Q000032:analysis*; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D010578:Petroleum; D012989:Soil Pollutants