Clean-up of polluted wet soils by solvent extraction

Present study describes a process for soil clean-up that, using a mixture of ethyl acetate and acetone, can treat wet soils without any pretreatment. According to a proprietary method, solvent mixture composition is chosen in relations to soil water content, in order to promote the formation of a dispersed slurry where soil-solvent contact is greatly enhanced. Bench scale treatment was carried out on soils coming from three different industrial sites and contaminated with chloro-organic compounds, included polychlorobiphenyls (PCB), and polynuclear aromatic hydrocarbons (PNA). Treatment process scheme depended on soil texture characteristics and soil-solvent separation represented a decisive factor; solvent mixture demonstrated high extraction efficiencies and rates in all examined cases. Cost estimate for a 5 t/h plant is about $200 per ton of treated soil.