COMBINED EFFECT OF SEQUESTRATION AND BIOREMEDIATION IN REDUCING THE BIOAVAILABILITY OF POLYCYCLIC AROMATIC-HYDROCARBONS IN SOD

A study was conducted to determine the combined effect of sequestratio n and laboratory-scale bioremediation on the bioavailability of polycy clic aromatic hydrocarbons in soil. After the compounds had aged for 1 40-203 days in soil, bacteria capable of degrading the compounds were added, and the availability of the hydrocarbons after bioremediation w as determined. Aging decreased the amount of phenanthrene, anthracene, fluoranthene, and pyrene available to bacteria as shown by increases in the amount of the compounds remaining after bioremediation and to e arthworms (Eisenia foetida) as shown by lower tissue concentrations, p ercentages assimilated, and bioconcentration factors. Aging also dimin ished the availability of anthracene to wheat and barley. Bioremediati on caused a marked diminution in the amount of phenanthrene, fluoranth ene, and pyrene taken up by earthworms. The smallest amounts of these three compounds were assimilated from soil in which they had aged and then been subject to biodegradation. The results show that the combine d effects of sequestration and bioremediation lead to a more marked re duction in bioavailability than either process alone.