Phytoremediation of contaminated sediments: evaluation of agronomic properties and risk assessment
2011
Bianchi, Veronica | Masciandaro, Graziana | Ceccanti, Brunello | Peruzzi, Eleonora | Iannelli, Renato
This study evaluates the possibility of reusing marine sediments in land management. The sediments, dredged from Livorno port (Italy), had previously been phytotreated, using a salt-tolerant plant cover and earthworms, with the aim of reducing the salt level and improving the texture and microbiology. In this study, sediments were investigated in order to: (1) test their capability to be used as a revitalised soil-like substrate (techno-soil), and (2) assess the human exposure risks associated with sediment management. Results obtained after 6 months of experiments performed with biological indicators composed of an association of graminae grass (Paspalum vaginatum), legumes (Trifolium alexandrinum) and earthworms (Eisenia foetida), showed that the substrate behaves like a natural soil capable of supporting biological life (total N=0.2%; total P=0.7%; EC=1.5 mS·cm ⁻¹; β−glucosidase=20 μ g PNP·g *h ⁻¹). It was also found that plants accumulate small amounts of heavy metals in shoot tissues (120 mg Zn·kg⁻¹; 25 mg Cu·kg⁻¹). In detail, risk analysis was performed considering: (1) sediment storage in a sealed disposal basin inside the Livorno port area, and (2) off-site phyto-remediation. The maximum hazard index was found for workers inside the port area, with values of 1.7 and 25 for dermal contact and vapour inhalation risks, respectively.
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