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2K - Sediment Assays (TUP/153) Application of bioassays to dredged sediments treatment plant. Cella, Arianna, Trentin, Marina, Perin, Guido1, 1 University Ca' Foscari, Venice, VE, Italy ABSTRACT- Fate of sediments dredged from excavation is a problem that becames severe day by day: many polluting substances are buried into them, rising serious problems in land management. In fact pollutants could be discharged in environment, and therefore reactions of environment itself should be investigated. Our purpose was to assess the efficiency of a treatment proposed by the Consortium for Industrial Development of Monfalcone to depurate sediments dredged out from lagoon channels. Contaminants are linked to the pelite fraction, so protocol provides a granulometric separation of the sediment before the addiction of Calcium oxide and cement to fine fraction to bind metal ions in cristalline structures. Bioassays give a complete response, integrating all the parameters (chemicals, physicals and biologicals) that influence sinergically the whole environment. The specie chosen is Skeletonema costatum, an ubiquitary diatom usually used in tests. It has been inoculated in different diluitions of sediments elutriates to evaluate the toxicity of interstitial and leaching waters, before and after the treatment in a pilot plant built up in laboratory. Key words: sediment treatment, bioassay, toxicity, Skeletonema costatum |
