| Popis: |
With the increasing need for the re-development of contaminated urban areas, the establishment of rapid and reliable analytical tools to support risk assessment and remediation, has become an important issue in recent years. In order to account for the different factors contributing to the bioavailability and ecotoxicity of pollutants, a complete ecotoxicity screening should use a combination of chemical and biological analyses. Chemical analyses cannot provide by themselves ecotoxicological information, and microorganisms, despite having proved to be good indicators of the toxicity of aquatic and terrestrial systems, usually cannot describe their composition. In this work the (eco)toxicity of Cr in soil contaminated with Cr salts or Chromite Ore Processing Residue (COPR) was studied and compared, using chemical analysis and bioassays. Chemical analyses were used to characterise Cr-contaminated soils to determine Cr and its chemical forms in a series of extracts. The bioassays were used to determine the (eco)toxicity of the extracts and soils characterised. The bioassays used included a single species bioassay (the luminescent bacteria Escherichia coli pUCD607), soil community assays (measurement of soil microorganisms respiration and phopholipid fatty acids) and plant assays (studying the growth of Hordeum vulgare in Cr-contaminated soils). The possible interactions between chemical composition and the (eco)toxicity observed in the bioassays was studied and compared by a range of statistical analysis. The results of this work as well as the feasibility and usefulness of this combined approach are presented and discussed. |
