Manufactured Gas Plants sites are mostly contaminated by Polycyclic Aromatic Hydrocarbons (PAHs) under the form of hydrophobic coal tar. Soil washing often uses surfactants or organic solvents, which have a significant environmental impact. This PhD work proposes an alternative way, based on seminatural, non-toxic and easily biodegradable cage-like molecules, β-cyclodextrins. They are able to solubilize hydrophobic molecules, as PAHs, thus extracted them from soil. In order to minimize products costs, a cyclodextrin recycling method, was successfully tested. Several experiments have been done, on a panel of former industrial sites soils, at laboratory and semi-pilot scale, with two conclusive trials of the full extraction process in a continuous mode. Comparison with existing methods indicates that the use of cyclodextrins is in most cases a better method than the ones based on surfactants or organic solvent, according to the current legislation (1996 European Directive IPPC).
