Role of Resuspended Sediments in the Transport and Bioaccumulation of Toxic Organic Contaminants in the Nearshore Marine Environment

Abstract

Abstract : The resuspension - deposition continuum plays a significant part in the distribution of fine grained sediments and associated organic pollutants in aquatic systems. The chemistry of resuspension was investigated during a year long study by submitting a variety of sediments, including relatively contaminated homogenized dredge spoils and moderately contaminated stratigraphically intact sediments, to artificial resuspension using a particle entrainment simulator. Fine grained sediments were entrained into the test cylinder under conditions that are similar to the resuspension energy that would be expected in a typical estuary. Samples of the resuspended material were collected under a variety of experimental conditions, for the evaluation of organic contaminants such as polycyclic aromatic hydrocarbons (typically associated with oil pollution as well as petrogenically derived) and PCBs (a mixture of toxic organic constituents associated with industrial pollution) as well as for geotechnical parameters such as grain size and particle number and organic carbon content. Results thus far indicate that the volume weighted resuspended sediment load is proportional to the shear stress energy applied for any given core. Moreover, each core has a relatively characteristic erodibility pattern, apparently depending upon the distinctive characteristics of the sediment, for example, grain size composition, biological density, homogeneity, etc. Resuspension, deposition, organic contaminants, PES, hydrocarbons Poly chlorinated biphenols, estuaries, fine sediments, shear stress energy, erodibility.