Removal of dioxins and dioxin-like PCBs from fish oil by countercurrent supercritical CO2 extraction and activated carbon treatment.
It has been known that fish oils are prone to contamination by polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (DL-PCBs). In this study, the removal of contaminants from fish oil by countercurrent supercritical CO(2) extraction (CC-SCE) and activated carbon treatment was investigated. Fish oil was treated by CC-SCE at 70 degrees C and 30MPa and with a CO(2)/oil ratio of 72; this resulted in a 93% reduction in the sum of PCDDs, PCDFs and DL-PCBs concentration level by and 85% reduction in toxic equivalency (TEQ). CC-SCE uses 40% less CO(2) and yields 30% more refined oil than semi-batch-type processes. Subsequent treatment by activated carbon reduced the concentration level by 94% and TEQ by 93%. CC-SCE is effective for the removal of DL-PCBs, whereas activated carbon treatment is effective for the removal of PCDD/Fs. These results reveal that the combination of CC-SCE and activated carbon treatment is applicable to the removal of PCDD/Fs and DL-PCBs from fish oil.
Kawashima
Ayato
A
Environmental Science for Industry, Faculty of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan. a-kawa@agr.ehime-u.ac.jp
Watanabe
Sakura
S
Iwakiri
Ryouji
R
Honda
Katsuhisa
K
D002245:Carbon Dioxide / Q000737:chemistry*; D002606:Charcoal / Q000737:chemistry*; D025924:Chromatography, Supercritical Fluid / Q000379:methods*; D004147:Dioxins / Q000737:chemistry / Q000302:isolation & purification*; D005395:Fish Oils / Q000737:chemistry*; D015394:Molecular Structure; D011078:Polychlorinated Biphenyls / Q000737:chemistry / Q000302:isolation & purification*
D004147:Dioxins; D005395:Fish Oils; D002245:Carbon Dioxide; D002606:Charcoal; D011078:Polychlorinated Biphenyls