Influence of the characteristics of soil and fly ash on the supercritical carbon dioxide extraction of dioxins.
Several investigations on the extraction of dioxins from soil and fly ash with supercritical fluid have been reported; however, few of them describe the influence of components on the extraction. We extracted dioxins from eight samples with different values of organic carbon content and surface area with supercritical CO(2) at a temperature of 463 K, a pressure of 40 MPa, and using 10% toluene as an entrainer. We researched the influence of the characteristics of soil and fly ash on supercritical CO(2) extraction of dioxins. The results revealed that the extraction efficiencies of PCDD/DFs and PCBs were high for all soil samples, while that of fly ash samples decreased with the increase in organic carbon content and surface area. The extraction efficiencies of dioxins from four standard samples, activated carbon, humic acid, alumina, and florisil, were also examined. The results revealed that the extraction efficiencies were strongly influenced by activated carbon like components present in the samples.
Kawashima
Ayato
A
Environmental Science for Industry, Faculty of Agriculture, Ehime University. a-kawa@agr.ehime-u.ac.jp
Miyawaki
Takashi
T
Honda
Katsuhisa
K
D001572:Benzofurans / Q000302:isolation & purification; D002244:Carbon / Q000737:chemistry*; D002245:Carbon Dioxide / Q000737:chemistry; D025924:Chromatography, Supercritical Fluid / Q000379:methods*; D060729:Coal Ash; D000072338:Dibenzofurans, Polychlorinated; D004147:Dioxins / Q000302:isolation & purification*; D052638:Particulate Matter / Q000737:chemistry*; D011078:Polychlorinated Biphenyls / Q000302:isolation & purification; D012987:Soil / Q000032:analysis*; D012989:Soil Pollutants / Q000737:chemistry*; D014961:X-Ray Diffraction
D001572:Benzofurans; D060729:Coal Ash; D000072338:Dibenzofurans, Polychlorinated; D004147:Dioxins; D052638:Particulate Matter; D012987:Soil; D012989:Soil Pollutants; D002245:Carbon Dioxide; D002244:Carbon; D011078:Polychlorinated Biphenyls