Bio2Remediation® as effective and self-sustainable tool to reduce persistent contaminants and to contrast accumulation of the new ones.

Bio2Remediation is a patented technology developed by Ca' Foscari University of Venice. This in situ remediation’s technology consists in a forced oxygenation of the water layer upon the sediment, in order to re-activate the microbial community capable to biodegradation and so to stimulate a renewed biocenosis. Then, a biocapping suitable to create a sediment surficial oxic layer and to strongly limit pollutant’s release from the deeper sediment layer is forming in a treated area. The Bio2Remediation was already applied in two different very polluted sites in the Venice Lagoon. Here, according to ecotoxicological point of view, we want to describe the results obtained appliyng this technology to Arsenale Vecchio basin, a polluted area of the ancient venetian shipyard, about one year after the end of the treatment. This area was chosen for the experimentation because of its limited size, shallow water and (nowadays) reduced boat traffic. The final aim was to compare the results obtained in the treated area vs. the no-treated area’s ones, in order to verify the treatment maintenance property, being the 16 polycyclic aromatic hydrocarbons (PAHs), focused by the U.S.-E.P.A., as priority pollutants to trace organic pollution with and without Bio2Remediation treatment. The content, the kind, the relative and absolute distribution of PAHs has been investigated in this sensitive area, strongly affected by various old and recent anthropogenic activities. It is really evident that PAH’s concentration decreases in treated area clearly after in situ remediation treatment with Bio2Remediation, showing both reduction of their absolute amount and different percentage distribution. Finally, in order to understand the PAH’s sources, diagnostic ratios (DR) as PAH’s contamination indexes have been applied to both treated and no-treated areas, suggesting a from fossil fuel combustion and/or from grass, wood or coal combustion origin, depending on the particular sample site. In conclusion, this work highlights that Bio2Remediation is pertaining as a new approach for the treatment of the contaminated sediment in situ, in particular showing a strong capacity both to reduce the amount of old persistent contaminant and to contrast the accumulate of new pollutant’s input.