| 1. |
- Cieplik, M.K., et al.
(författare)
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Formation of dioxins from combustion micropollutants over MSWI fly ash.
- 2006
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Ingår i: Environmental Science and Technology. - 0013-936X. ; 40:4, s. 1263-9
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Tidskriftsartikel (refereegranskat)abstract
- Formation of polychlorinated dibenzofurans and dibenzo-p-dioxins (PCDD/Fs) from a model mixture of products of incomplete combustion (PICs) representative of municipal solid waste incineration (MSWI) flue gases, over a fixed bed of MSWI fly ash has been investigated. For comparison, a single model compound (chlorobenzene) was also briefly studied. A newly developed lab-scale system enabled the application of (very) low and stable concentrations of organic substances--of 10(-6) M or less-to approach realistic conditions. Samples taken at several time intervals allowed the observation of changes in rates and patterns due to depletion of the carbon in fly ash. The model flue gas continuously produced PCDDs and PCDFs after the de novo reaction had ceased to occur. Dioxin output levels are comparable to those of "old" MSW incinerators. Replacing the PIC trace constituent phenol by its fully 13C-labeled analogue led to, e.g., PCDD with one labeled ring as prominent product, meaning that the formation is about first order in phenol, contrary to earlier assumptions. The meaning of the results for the formation of dioxins in the MSWI boiler is discussed.
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| 2. |
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| 3. |
- Marmon, Sofia, 1982, et al.
(författare)
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Removal of lipids, dioxins, and polychlorinated biphenyls during production of protein isolates from baltic herring (Clupea harengus) using pH-shift processes
- 2009
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Ingår i: Journal of Agricultural and Food Chemistry. - : American Chemical Society. - 0021-8561 .- 1520-5118. ; 57:17, s. 7819-7825
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Tidskriftsartikel (refereegranskat)abstract
- Dioxins and PCBs are toxic, lipophilic, and persistent substances that impose a serious health threat. A major risk of exposure to these toxic substances is consumption of fish from polluted waters, such as the Baltic Sea. The aim of this study was to investigate if pH-shift processing of Baltic herring with elevated toxicity levels could be used to produce a protein isolate with low fat content and, thereby, reduced dioxin and PCB levels. Both acid (pH 2.7) and alkaline (pH 11.2) pH-shift processing were investigated and resulted in efficient reduction of fat, dioxin, and PCB levels. A reduction of 70-80% per amount of protein was determined for all of these parameters. The amounts, and thus the removal, of lipids and dioxins (R(2) = 0.952) as well as lipids and PCBs (R(2) = 0.996) were highly correlated (p < 0.01). A mass balance of the alkaline pH-shift process showed that most of the fat and pollutants were found in the floating fat emulsion layer of the first centrifugation, followed by the pellet of the first centrifugation. These data show that the pH-shift protein isolation technique can be used to process herring with elevated dioxin and PCB levels and thereby increase the usage possibilities of such fish.
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