Bioremediation of coal tar PAH in soils using biodiesel

The addition of biodiesel together with nitrate and phosphate to soil conta ining coal tar, in laboratory and field experiments, resulted in degradatio n of coal tar polycyclic aromatic hydrocarbons (PAH) that was not apparent when the nutrients alone were added. The addition of motor diesel fuel inst ead of biodiesel was also tested. Over the 55 days of the field and laborat ory experiments, the biodiesel resulted in an increased degradation of naph thalene in the coal tar by 52% and 85%, respectively, and motor diesel resu lted in increased depletions of 85% and 96%, respectively. Other PAH contai ning up to four rings were depleted to lesser extents. The increases in PAH biodegradation by the diesel treatments were ascribed to tar solubilisatio n and dispersion thereby increasing the PAH bioavailability. The ready biod egradability and low phytotoxicity of biodiesel suggest that it may be suit able as a novel treatment for the bioremediation of coal tar contaminated s oils. (C) 2001 Elsevier Science Ltd. All rights reserved.