Migration of Water-Soluble Oil Components in Some Soils of Bashkortostan

The migration of water-soluble fraction of petroleum hydrocarbons in typical soils of Bashkortostan is studied. The possibility of their water migration in Fluvic Phaeozems, Haplic Phaeozems, and Amphiskeletic Pantocalcic Chernozems is determined by data of a lysimetric model experiment. Dissolved organic substances, which pass into lysimetric waters from oil-contaminated soils, include the components that are not extracted by hexane, but are characterized by fluorescence in water at the wavelengths typical for petroleum products. These substances differ from soluble organic matter of background soils by higher HIX (humification indices) and presumably represent oxidized transformation products of petroleum hydrocarbons. Lysimetric waters from all oil-contaminated soils are biotoxic, regardless of the presence of nonpolar petroleum hydrocarbons. The toxicity T-index is in positive correlation with the content of dissolved organic carbon and chloride ions, accompanying oil pollution of soils.