USE OF NONIONIC POLYMERIC ADSORBENT TO ASSESS PAH BIOAVAILABILITY IN CONTAMINATED MARINE SEDIMENT

A study was conducted to investigate the feasibility of using an XAD-assisted desorption assay to assess the bioavailability of PAHs in aged field-contaminated marine sediment. Various amounts of nonionic polymeric adsorbent XAD-2 were added to abiotic sediment-seawater slurry systems to adsorb the desorbed PAHs from the sediment and thus accelerate further desorption. A study of PAH biodegradation was also performed utilizing microorganisms indigenous to the sediment. Both the rates of PAH desorption in the XAD-assisted desorption assay and their degradation rates in the biodegradation study decreased with time and eventually approached zero. The comparison of the final residual PAHs in two studies showed a close correlation, especially for PAHs with less than five benzene rings, for which significant degradations were observed. The data suggest that the XAD-assisted desorption assay is promising in measuring the bioavailability of PAHs in the field-contaminated sediments and predicting the end point of the bioremediation of PAHs.