Applications of PTMs Speciation for Risk and Remediation Assessment

A multidisciplinary approach, including chemical, physical and mineralogical characterisation of contaminants and soils, has been shown to be fundamental to understand comprehensively the history of industrial soil contamination, to assess the potential and the actual risk associated with elevated levels of PTMs in soil (i.e. the relation of PTMs with soil matrix and their chemical accessibility and mobility) and to define the feasibility of potential remediation treatments (Adriano et al., 2004 Banat et al., 2005 Gasser and Dahlgren, 1994 Sahuquillo et al., 2003 Venditti et al., 2000a,b). 

Quantitative chromium solid-state speciation in chromite ore processing residue (COPR) has defined the mineral species and the processes controlling the retention and release of Cr(VI) from CO PR-contaminated sites (Hillier et al, 2003). Information that, used within a process-based modelling framework, has helped to predict the impact of changes in physicochemical conditions on the COPR, to test the extent to which the system may be considered at equilibrium and that, therefore, need to be considered within the context of informed remediation (Geelhoed et al, 2001). 

The possibility of using Lolium perenne for re-vegetation of soil from a former ferrous metallurgical site contaminated by Cu, Pb and Zn was demonstrated in a greenhouse study by Arienzo et al. (2004). Plants were healthy with 100% survival in all cases, with no macroscopic symptoms of metal toxicity. The high pH of the 

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Applications of PTMs Speciation for Risk and Remediation Assessment 201... 

Speciation science seeks to characterise the various forms in which PTMs occur or, at least, the main metal pools present in soil. This chapter provides a review of the single and sequential chemical extraction procedures that have been more widely applied to determine the plant and the human bioavailability of PTMs from contaminated soil and their presumed geochemical forms. Examples of complementary use of chemical and instrumental techniques and applications of PTMs speciation for risk and remediation assessment are illustrated. 

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