Modified Polytopic Vector Analysis To Identify and Quantify a Dioxin Dechlorination Signature in Sediments. 2. Application to the Passaic River
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- 作者：Noé ; mi Barabá ; s ; Pierre Goovaerts ; and Peter Adriaens
- 刊名：Environmental Science & Technology
- 出版年：2004
- 出版时间：March 15, 2004
- 年：2004
- 卷：38
- 期：6
- 页码：1821 - 1827
- 全文大小：192K
- 年卷期：v.38,no.6(March 15, 2004)
- ISSN：1520-5851
文摘
Persistent contaminants such as dioxins have beendocumented to undergo dechlorination reactions in thelaboratory; however, little is known about the importanceof these reactions in the field. Polytopic vector analysis(PVA) is a statistical pattern recognition technique formultivariate data traditionally used to identify fingerprintsof contaminant sources. A modified PVA algorithm withuncertainty analysis was used to model dechlorinationfingerprints and sources. The technique was applied to 351sediment core-derived dioxin samples from the lowerreach of the Passaic River, New Jersey. A dechlorinationfingerprint was identified with a highly positive 2,3,7,8-tetraCDD component and a highly negative heptaCDDcomponent. The most important industrial source of 2,3,7,8-tetraCDD is a fingerprint related to 2,4,5-trichlorophenoxyacetic acid production. The dechlorination contribution tothe data variance is 3.00 ± 1.00%, corresponding to anaverage of 1.2 
g/kg of 2,3,7,8-tetraCDD per sample at theexpense of heptaCDD. The possible occurrence ofdechlorination was validated by comparing the localdechlorination contribution in the results to the value ofthe ratio 2,3,7,8-tetraCDD/total 2,3,7,8-PCDD, which indicatesdechlorination in the laboratory. Bootstrap uncertaintyanalysis yielded the same dechlorination EM in 40% of therealizations. The results indicated that bootstrapping isan important statistical tool to quantify uncertainties withrespect to the dechlorination EM and some of thesource EMs.
g/kg of 2,3,7,8-tetraCDD per sample at theexpense of heptaCDD. The possible occurrence ofdechlorination was validated by comparing the localdechlorination contribution in the results to the value ofthe ratio 2,3,7,8-tetraCDD/total 2,3,7,8-PCDD, which indicatesdechlorination in the laboratory. Bootstrap uncertaintyanalysis yielded the same dechlorination EM in 40% of therealizations. The results indicated that bootstrapping isan important statistical tool to quantify uncertainties withrespect to the dechlorination EM and some of thesource EMs.