Polyethylene devices and the effects of sediment resuspension on the cycling of PAHs and PCBs in the lower Hudson Estuary

摘要

In order to examine the importance of sediment resuspension on the sediment bed-to-water column transport of hydrophobic organic contaminants (HOCs) in the lower Hudson Estuary, the following areas of research were pursued: 1) a passive, in situ sampler, a polyethylene device (PED), for measuring HOCs in the aquatic environment was developed; 2) the desorption rate of pyrene, a polycyclic aromatic hydrocarbon (PAH), from native Hudson River sediments was measured, and 3) pyrene and 2,2',5,5'-tetrachlorobiphenyl (PCB #52), a polychlorinated biphenyl (PCB), concentrations were measured in the lower Hudson Estuary so that the input of these chemicals as a result of sediment resuspension could be compared to modeling expectations and the contribution of sediment resuspension to these chemicals' cycling could be quantified. The use of a new passive, in situ sampler, a polyethylene device (PED), for measuring hydrophobic organic contaminants (HOCs) in the aquatic environment was demonstrated. Like semipermeable membrane devices (SPMDs) and solid-phase microextraction (SPME), PEDs passively measure the concentration of chemical present in the dissolved phase. PEDs provide for in situ, time-averaged measurements with fast equilibration times (on the order of days) and simple laboratory extraction. Polyethylene-water equilibrium partitioning constants (KpEws) and polyethylene diffusivity coefficients (DPEs) were measured in the laboratory so that dissolved concentrations could be calculated subsequent to PED extraction.