Source identification, geochemical normalization and influence factors of heavy metals in Yangtze River Estuary sediment
Source identification, geochemical normalization and influence factors of heavy metals in Yangtze River Estuary sediment
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长江口沉积物重金属来源识别、地球化学归一化及影响因素
DOI：
10.1016/j.envpol.2018.05.050
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发表时间：
2018-10-01
影响因子：
8.9
通讯作者：
Liao, Huijie
中科院分区：
文献类型：
--
作者：
Sun, Xueshi;Fan, Dejiang;Liao, Huijie
2015年和2016年在长江口（YRE）的52个站点采集了40个表层样品和12个沉积物岩心。采用95%线性预测区间（LPI）和主成分分析（PCA）对金属来源和粒度效应（GSE）进行评价。结合pH、Eh、DO、盐度、温度和浊度的原位理化性质，阐明了环境因素与河流-河口-陆架体系中重金属命运的关系。研究表明，沉积物中金属元素从河口向邻近陆架和河道方向呈减少趋势，Zn、Cu和Cr主要来源于整个流域的自然过程，而Pb则通过大气沉降有人为输入。此外，考虑到Al和重金属浓度之间的最佳拟合回归曲线，以及传统c元素/C-Al方法的不足，我们提出了一种能够消除重金属的GSE的方法（Al- sn: Al -scope归一化），并将其应用于其他河口。经Al-scope归一化后，从河道到河口和陆架的沉积物中Zn、Cu和Cr的含量相对稳定，证实了沉积物粒度的变化几乎完全解释了YRE沉积物毒性的分布规律，而河口沉积物中Pb的富集可归因于其化学种类和物理化学性质。研究结果进一步表明，在沉积物成分复杂的河口或类似环境中，沉积物污染物的粒度与空间行为之间的关系应优先于污染评价和物源判别。(C) 2018 Elsevier Ltd.版权所有。
Sediment samples, including 40 surface samples and 12 sediment cores, were collected from 52 stations of the Yangtze River Estuary (YRE) in 2015 and 2016. The 95% linear prediction intervals (LPI) and principal components analysis (PCA), were conducted to evaluate the metal sources and grain-size effect (GSE). The in situ physico-chemical properties of pH, Eh, DO, salinity, temperature and turbidity were combined to elucidate the relationships between environmental factors and the fate of heavy metals in the river-estuary-shelf system. This study indicates a decreasing trend of metals in sediments from the estuary towards the adjacent shelf and the river channel and that Zn, Cu and Cr are mainly derived from natural processes throughout the catchment, whereas Pb appears to have anthropogenic inputs via atmospheric deposition. Furthermore, considering the best fit regression lines between the concentrations of Al and heavy metals as well as the deficiencies of the conventional C-elements/C-Al method, we introduce an approach (Al-SN: Al -scope normalization) that can eliminate the GSE on heavy metals and be applied to other estuaries. After Al-scope normalization, the relatively constant levels of Zn, Cu and Cr that remain in sediments from the river channel to the estuary and shelf confirmed that the variation of grain size in sediments almost entirely explained the distribution patterns of sediment toxicity in the YRE, while the enrichment of Pb in estuarine sediments could be attributed to its chemical species and physico-chemical properties. The results further suggest that the relationship between grain size and spatial behavior of sediment pollutants should be given priority over the contamination assessment and provenance discrimination in estuarine or similar environments with complex sediment compositions. (C) 2018 Elsevier Ltd. All rights reserved.