RAPID SCREENING OF PAH-RESIDUES IN BIOREMEDIATED SOILS

Humic acids isolated from soils contaminated by polycyclic aromatic hy drocarbons (PAH) and from non-contaminated soils were investigated by analytical pyrolysis to examine the abundance and structure of soil bo und PAH-residues. PAHs which are not extractable by organic solvents c ould be liberated from humic substances by analytical pyrolysis. Pyrol ysates of humic acids derived from biodegradation experiments with PAH contaminated soils revealed a 2 to 8 fold enrichment of PAHs compared to those from non-polluted soils, This enrichment was also observed i n humic substances isolated from contaminated field samples during a r emediation experiment. Environmental implications for the formation of soil bound residues during bioremediation are discussed.