Advance in supercritical CO2 fluid extraction of contaminants from soil

CO2 has many attractive physical and chemical properties under supercritical state, and it is considered as a kind of “green” solvent for its non-toxicity, clean and easy obtained. In recent years, studies related to phase behavior and materials solubility in supercritical CO2(SC-CO2) have been paid more attention widely. A relative developing technology of supercritical fluid extraction (SFE) draws great attention in many fields. This paper reviews broad studies using SC-CO2 to remove contaminants such as PAHs, PCBs and heavy metals from soil. According to the efficiency of SFE, the factors including temperature, pressure and cosolvent were discussed. The authors finally pointed out the advantages and drawbacks of SFE while comparing with other soil remediation approach, and also discussed the prospect of SFE and feasible application in soil remediation in the future.