Prediction of Persistent Organic Pollutants Biodegradation in Contaminated Marine Sediments Using Passive Sampling Probes

The aim of this study is to evaluate a new configuration (new materials) of the commercial passive sampler Chemcatcher as probe for predicting the bioavailability of persistent organic pollutants in marine sediments. To predict the availability of pollutants to biota, it is important to understand both solution- and solid-phase processes in the sediment, including the kinetics of pollutants release from its binding agent (ligand and/or particle). The present study examined the kinetic of desorption and biodegradation of Polycyclic Aromatic Hydrocarbons (PAHs) in two different marine sediments sampled in the Adriatic Sea. The sediments were spiked with a standard mix of 16 PAHs in the range of 11-12 mg/Kg (dry sediment). Formaldehyde was added into the sediments to prevent biodegradation. After equilibration, the passive probes were placed in the specimens with prevented biodegradation, recovered and analyzed at prefixed time slots (in the range of 50 days) for the assessment of the accumulated PAHs; in parallel a little amount of sediments was collected and the residual concentration of PAHs was measured. Free PAHs in the sediment pore waters were also determined. The results suggest that the kinetically labile solid-phase pool of PAHs, which is included in the DGT measurement, played an important role in biodegradation processes along with the free PAHs in sediment pore water.