Heavy-metal distribution in pore waters of the Cona Marsh: A preliminary investigation on surface sediments

Summary The results of an investigation about the heavy-metal distribution in pore waters of an estuarine shallow-water system (Cona Marsh, Venice Lagoon) are described. The area was sampled for surface and subsurface sediments; pore waters were extracted by centrifugation and heavy-metal concentration measured by means of PIXE technique. A high variability of heavy-metal concentration was observed in pore waters of sampled sites, as a result of physico-chemical conditions in the water sediment column, with a different spatial distribution between two groups of metals (Fe, Mn and Crvs. Cu, Ni and Zn). Concentration gradients between pore and bottom waters were evaluated in order to investigate the metal enrichment as a function of their mobility in the sediment and diagenesis phenomena. Paper presented at the IX Congresso del Gruppo Nazionale per la Fisica dell'Atmosfera e dell'Oceano, June 8–10, 1992, Rome.