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首页> 外文期刊>Applied Geochemistry: Journal of the International Association of Geochemistry and Cosmochemistry >Lead in sediments and suspended particulate matter of the German Bight: natural versus anthropogenic origin
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Lead in sediments and suspended particulate matter of the German Bight: natural versus anthropogenic origin

机译：德国湾的沉积物和悬浮颗粒物中的铅：自然来源和人为来源

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Sediments (568) and suspended particulate matter (SPM. 302 samples) of the southern German Bight and the adjacent tidal flat areas were analysed for selected major elements (A], Fe. K), trace metals (Mn. Pb). and Pb-206, Pb-207 ratios using XRF, ICP-OES, ICP-MS. For selected samples a leaching procedure with 1 M HCl was used to estimate the Pb fraction associated with labile phases (e,g. Mn: Fe-oxihydroxide coatings) in contrast to the resistant mineral matrix. Enrichment factors versus average shale (EFS) reveal elevated Pb contents for all investigated sediments and SPM in the following order: Holocene tidal flat sediments (HTF, human-unaffected) 5 mg l(-1)) < offshore SPM (<5 mg l(-1)). Besides pollution, RTF contain elevated amounts Of natural Pb-rich materials (K-feldspars and heavy minerals due to a man-made high-energy environment (dike building) in comparison to HTF. Pb-206/Pb-207 ratios of RTF (1.192 +/- 0.019) are similar to the local geogenic background. determined from HTF (1.207 +/- 0.008). In contrast, Pb isotope ratios of nearshore SPM (1.172 +/- 0.007) and offshore SPM (1.166 +/- 0.012) show a distinct shift towards the anthropogenic/atmospheric signal of 1.11-1.14. This difference between RTF and SPM supports the assumption of low deposition rates OF fine material in the intertidal systems. As the Pb-206/Pb-207 ratios of SPM do not reach the pure anthropogenic signal. the adsorbed Pb fraction was examined (leaching). However, the leachates also contained large amounts of geogenic Pb (SPM approximate to40%. recent sediments approximate to60%). The authors assume that the uptake of natural Pb occurs in nearshore waters, presumably in the turbid intertidal systems, Possible sources for dissolved Pb are mobilisation during weathering (geogenic signal) and dissolution of oxihydroxide coatings with subsequent release from porewaters, and unspecific riverine input. Comparatively small parts of SPM leave the coastal water mass and reach the open North Sea. This process therefore leads to a decontamination of the tidal flat sediments. Due to more pronounced atmospheric input, the offshore SPM becomes enriched in amhropogenic Pb as indicated by decreasing Pb-206/Pb-207 ratios with increasing distance from the coast. (C) 2002 Elsevier Science Ltd. All rights reserved. [References: 51]
机译：分析了德国南部海岸线和邻近的滩涂区域的沉积物（568）和悬浮颗粒物（SPM。302样品），以分析选定的主要元素（A]，Fe。K），微量金属（Mn。Pb）。使用XRF，ICP-OES和ICP-MS测定Pb-206，Pb-207的比例。对于选定的样品，与抗性矿物基质相比，采用1 M HCl浸出程序来估算与不稳定相（例如，Mn：Fe-羟基氧化物涂层）相关的Pb分数。富集因子与平均页岩（EFS）揭示了所有调查的沉积物和SPM的Pb含量按以下顺序升高：全新世潮汐平坦沉积物（HTF，人类未受影响）<最新潮汐平坦沉积物（RTF） 5 mg l（-1））<离海SPM（<5 mg l（-1））。与HTF相比，RTF除污染外，还包含大量的天然富含Pb的材料（由于人为的高能环境（堤坝建筑）而导致的钾长石和重矿物）。RTF的Pb-206 / Pb-207比（ 1.192 +/- 0.019）与当地的地质背景相似（由HTF（1.207 +/- 0.008）确定），相比之下，近海SPM（1.172 +/- 0.007）和近海SPM（1.166 +/- 0.012）的铅同位素比）显示出明显的向人为/大气信号1.11-1.14的转变.RTF和SPM之间的差异支持了潮间带系统中精细物质沉积速率较低的假设。因为SPM的Pb-206 / Pb-207比尚未达到人为的纯信号，对吸附的Pb进行了检测（浸出），但渗滤液中还含有大量的地质Pb（SPM约为40％，最近的沉积物约为60％）。发生在近岸水域，大概是在潮间带系统中，溶解的Pb的可能来源是在风化过程中的动员（基因信号）和羟基氧化物涂层的溶解，随后从孔隙水中释放出来，以及不确定的河流输入。 SPM的一小部分离开沿海水体并到达北海。因此，该过程导致对滩涂沉积物进行去污。由于大气输入的增加，离岸SPM的人为化Pb含量增加，这表明Pb-206 / Pb-207比例随与海岸的距离增加而降低。 （C）2002 Elsevier ScienceLtd。保留所有权利。 [参考：51]

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