화학공학소재연구정보센터
Separation Science and Technology, Vol.38, No.12-13, 2979-2993, 2003
Supercritical fluid extraction of 1,2,4-trichlorobenzene from DOE job control wastes
At U.S. Department of Energy (DOE) sites, significant amounts of job control waste (JCW) need to be disposed. This JCW is generated and contaminated with polychlorinated biphenyls (PCBs) during cleanup operations. A commercial, plant-based absorbent material, "Toxi-dry," is used extensively for decontamination and decommissioning of DOE waste sites and is classified a hazardous JCW after use. In this investigation, 1,2,4-trichlorobenzene (TCB) was chosen as the surrogate for PCBs. As a promising separation technology, supercritical fluid extraction (SFE) was investigated for removing and recovering PCBs from contaminated of JCW. TCB was extracted from Toxi-dry using both pure and modified supercritical carbon dioxide. It was found that at constant pressure, increasing temperature from 40 to 80degreesC greatly improved the recoveries, while the pressure effect of SFE was not as clear as the temperature effect. With 5wt% acetone or ethanol added as cosolvent, the efficiency of SFE of TCB was also significantly improved.