RECOVERING OF DREDGED SEDIMENTS CONTAMINATED BY TOTAL PETROLEUM HYDROCARBON TO PRODUCTIVE SOILS: THE MYCOREMEDIATION APPROACH IN THE BIORESNOVA PROJECT

Chemo-physical treatments to remove salinity and metal contamination from dredged sediments were applied in combination to bio-based approaches (mycoremediation). New fungal specimen were isolated from the contaminated sediments, massively grown and re-inoculated in the matrix in treatment to remove the Total Petroleum Hydrocarbon contamination (TPH). Toxicological assays were exploited to estimate the sediment remediation efficiency over time. Indeed, the only chemical characterization of polluted matrices does not allow to predict the residual toxicity of the latter eventually related to the permanence of a residual contamination by the parental pollutants, to their degradation intermediates and/or to the synergic actions of the both. Higher plants (Vicia faba L.) were exploited as indicators of the quality of the treated sediments and used both for the continuous monitoring of the remediation processes and for the evaluation of the final product eco-safety. Biological parameters such as the genotoxicity by means of cytological analysis of mitotic behavior of root meristems were evaluated based on the detection of chromosomal aberrations in mitotic cells, and of micronuclei formation, detectable in interphase cells. The combination of the Chemo-physical and the Bio-based approach was able to remove the organic contamination (TPH) and the excess of sodium salts that constitute a critical point for the eventual re-allocation of dredged sediments. At the same time the sediments were detoxified and actually gained the biochemical traits of humified productive soils, eventually suitable for their safe re-allocation in the environment.