Dioxins in primary kaolin and secondary kaolinitic clays.
Dioxins in primary kaolin and secondary kaolinitic clays.
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DOI：
10.1021/es103000v
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发表时间：
2011-01
影响因子：
11.4
通讯作者：
M. Schmitz;G. Scheeder;Sarah Bernau;R. Dohrmann;K. Germann
中科院分区：
文献类型：
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作者：
M. Schmitz;G. Scheeder;Sarah Bernau;R. Dohrmann;K. Germann
自 1996 年以来，世界各地在动物饲料生产和各种其他应用中用作抗结块剂的第三纪球粘土中多次检测到二恶英。这些天然粘土中的二恶英不太可能是人为来源，但尚未建立二恶英富集模型。提出了一个假设模型，该模型解释了粘土沉积过程中自然添加导致的第三纪高岭土粘土的高度可变的二恶英负荷。为了证明这一假设，在欧洲的三个剖面收集了第三纪原生非沉积高岭土和沉积高岭土，并进行了矿物学、化学、有机碳和多氯二苯并-对-二恶英/-呋喃 (PCDD/F) 分析。原生高岭土、高岭土和褐煤粘土几乎不含 PCDF。原生高岭土 (3-91 pg/g) 和次生高岭土 (711-45935 pg/g) 以及褐煤粘土 (13513-1191120 pg/g) 之间的 PCDD 浓度差异显着。次生高岭土和褐煤粘土的二恶英含量比原生高岭土或最近的环境环境高约 10 至数千倍。二恶英浓度从八氯二苯并-对-二恶英降低到四氯二苯并-对-二恶英，并表现出“自然形成模式”。未发现 PCDD/F 浓度与粘土的整体成分之间存在相关性。这些发现支持了沉积过程中粘土中二恶英富集的假设。
Since 1996 dioxins have been repeatedly detected worldwide in Tertiary ball clays used as anticaking agent in the production of animal feed and a variety of other applications. The dioxins of these natural clays are very unlikely of anthropogenic source, but no model of dioxin enrichment has been established. A hypothetical model is presented which explains the highly variable dioxin loadings of the Tertiary kaolinitic clays by natural addition during clay-sedimentation. To prove this hypothesis, Tertiary primary nonsedimentary kaolin and sedimentary kaolinitic clays were collected at three profiles in Europe and analyzed for mineralogy, chemistry, organic carbon, and polychlorinated dibenzo-p-dioxins/-furans (PCDD/F). Primary kaolin, kaolinitic, and lignitic clays contained almost no PCDFs. PCDD concentration differed markedly between primary kaolin (3-91 pg/g) and secondary kaolinitic clay (711-45935 pg/g), respectively, lignitic clays (13513-1191120 pg/g). The dioxin loading of secondary kaolinitic and lignitic clays is approximately 10 to a few thousand times higher than in the primary kaolin or recent environmental settings. The dioxin concentrations decrease from octachlorodibenzo-p-dioxin to the tetrachlorodibenzo-p-dioxins and exhibit the "natural formation pattern". No correlation between PCDD/F concentration and bulk composition of clays was found. These findings support the hypothesis of the enrichment of dioxin in clays during sedimentation.