Enhanced Natural Biodegradation of Diesel Fuel Contaminants in Soil by Addition of Whey and Nutrients

Abstract

The contamination of soils by petroleum hydrocarbons, such as diesel fuel, has since many years been a serious environmental problem. Treatment of contaminated areas is a concern for governments and environmental authorities in several countries and efforts have been done with the purpose to eliminate this problem. Different methods have been tested and today the most common technique involves the excavation and transportation of contaminated soil to special treatment facilities. In earlier studies we have demonstrated the effect of adding organic amendments, such as fermented whey, on the biodegradation of n-alkanes in diesel contaminated soil. Non-fermented sweet whey also proved significantly to enhance the biodegradation of an aromatic substance (phenanthrene) in contaminated soil. The current paper presents the results of an in-situ field test at a former gas station in the north of Sweden. In parallel to the field study, biodegradation profiles were monitored under controlled laboratory conditions by taking soil samples from the contaminated site and spike them with diesel fuel. The experiments were carried out by adding whey and mineral nutrients (NPK) to the test area and to the laboratory samples, and monitor the degradation of hydrocarbons by gas chromatographic analysis of extracted soil samples. Significant effects on the degradation rates were achieved in the laboratory tests. For the in-situ test, however, no such positive effects could be registered.