Salix rubens and Salix triandra Species as Phytoremediators of Soil Contaminated with Petroleum-Derived Hydrocarbons

Abstract

The petroleum industry activities provide po- tential risks to the environment because they can con- taminate ecosystems with different organic compounds in the production chain. Several accidents with transport and handling of petroleum and related products oc- curred in urban areas with harmful effects to the quality of life and economy. In the 1990s, bioremediation and phytoremediation technologies as economically feasible alternatives to repair the environmental damage were developed. In this study, the potential of the willows Salix rubens and Salix triandra were evaluated with regard to the phytoremediation of soils contaminated with petroleum-derived hydrocarbons (total hydrocar- bons and polycyclic aromatic hydrocarbons (PAHs)). The PAHs were quantified by extraction from soils and plants using dichloromethane under ultrasonication. The HPLC analysis was performed with GC/MSD equipment. The total hydrocarbons present in uncon- taminated soil were quantified by the sum of animal/ vegetable oils and greases and mineral oils and greases according to Standard Methods 5520 (1997). The two willows species S. rubens and S. triandra were resistant during the project development. In the contaminated soil, in which both species were planted,the total hydro- carbons concentration was reduced near 98 %. The PAHs content was remarkably reduced as well. Pyrene showed an initial concentration of 23.06 μ gk g �1 ,d e- creasing in most cases to 0.1 μ gk g �1 or to undetectable levels. Chrysene decreased from 126.27 μ gk g �1 to undetectable levels. Benzo(k)fluoranthene and benzo (a)pyrene concentrations had also showed a decrease from 28.44 and 3.82 μ gk g �1 , respectively, to undetect-