用超临界流体萃取方法处理多氯联苯污染物

Study on Supercritical Fluid Extraction of PCBs in Contaminative Soils

测定了三种多氯联苯（ＰＣＢｓ）同系物：４，４’－二氯联苯，２，３’，４’，５－四氯联苯，２，２’，３，３’，４，４’－六氯联苯在超临界ＣＯ２中的溶解度。实验是用静法在一个带可视窗的高压平衡池内进行。实验的压力为９～４５ＭＰａ，温度为３０８．１～３２９．１Ｋ。同时研究了用超临界流体萃取技术处理被ＰＣＢｓ污染的固体物的方法。测定其萃取ＰＣＢｓ的传质速率及有效性，实验压力为７．５～６０ＭＰａ，实验温度为３０５．５～３１３．１Ｋ．ＣＯ２流率为０．７ｇ／ｓ。

The solubilities of three kind of solids polychlorinated biphenyls (PCBs),4,4'-dichlorobiphenyl, 2,3',4',5 '-tetrachlorobiphenyl, and 2,2',3,3',4,4'-hexachlorobiphenyl in supercritical CO2, have been measured at temperature from 308.1 to 328.1 K, and pressure from 9 to 45 MPa. The data were obtained in a static apparatus with a high pressure equilibrium view Cell. Also, the characteristic of supercritical fluid extraction for the cleaning up of soils which are contaminated with PCBs, have been studied. An one-pass flow equipment was used tO abtain the extraction rate and the efficiency of removal of PCBs from contaminated soils. The experimental conditions are: pressure from 7.5 to 60MPa, temperature from 3o5.5 to 313.1 K, now rate or CO2 of o.7 g / s.