超临界CO_2流体萃取土壤中污染物的应用研究进展

CO2在超临界状态下具有许多独特的物理化学性质,作为一种＂绿色＂溶剂,它具有无毒、无污染、易获取等优点。近年来,有关超临界CO2流体热力学相行为和溶解度性质的研究引起人们广泛的关注,与之密切相关的超临界流体萃取技术已在许多领域得到重视和发展。根据近年国内外运用超临界CO2流体对土壤中多环芳烃、多氯联苯、重金属等污染物的萃取应用,分析了温度、压力、共溶剂等因素对萃取效果的影响,通过与其他土壤修复技术的比较,展望了超临界流体萃取技术应用于土壤修复领域的可行性和研究方向。

Advance in supercritical CO_2 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.