| 摘要: |
| 1993年7－8月，在上海长江口南岸和杭州湾北岸淤泥质潮滩不同地貌部位，采集表层沉积物和柱状沉积物样品，采用筛析法、离心法、火焰原子吸收法、210Pb法等分别对沉积物粒度、重金属总量、不同粒级重金属含量以及沉积速率等进行了分析和测定。结果表明，潮滩沉积物重金属的空间分布格局并不受沿岸排污的直接影响，而与沉积动力作用密切相关。在水动力条件较弱的淤涨岸段和高潮滩部位，伴随着细颗粒泥沙的大量堆积，Cu，Zn，Pb，Cr，Cd等重金属元素明显趋于富集。 |
| 关键词: 淤泥质潮滩 重金属 累积 动力学 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金资助项目，49271009号 |
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| DYNAMIC ACCUNIULATION OF HEAVY METALS IN TIDAL FLAT SEDIMENTS OF SHANGHAI |
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Xu Shiyuan, Tao Jing, Chen Zhenlou, Chen Zhongyuan, Lu Quanrong
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Department of Geography ，East China Normal University , Shanghai 200062
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| Abstract: |
| Based on the long-term observation of Shanghai tidal flats south of the Changjiang River mouth and north of Hangzhou Bay respectively, this study used 45 surface sediment samples and 6 sediment cores collected during July and August in 1993. The sampling sites were distributed along the stable bank, accumulating bank, and eroded bank, located respectively at the high, middle and low tidal flats. Sample analysis includes particle size, heavy metal contents in different size sediments (Cu, Zn, Pb, Cr, Cd) and 210Pb activity in cores. Atomic absorption spectrometer was used for heavy metal testing. The results showed that the spatial distribution of heavy metals in tidal flat sediments was not directly influenced by the discharges of municipal sewerage or industry wastes, but was closely related to the local sedimentary dynamic conditions. At the accumulating bank and high tidal flat, where the sedimentary dynamic processes were relatively inactive, heavy metals tended be enriched along with the rapid deposition of fine particles (mainly finer than 16μm). Site A sediment heavy metal content rates of the high tidal flat to the middle and low tidal flats ranged respectively from 1.5 - 9.8. Calculation results indicated that both the natural sediment flux and artificial sediment flux of heavy metals of the accumulating bank, greatly surpassed those of the stable bank, and that of the eroded bank, with Zn and Cd among the most distinctive. It was clear that municipal sewerage and industry wastes have produced a serious impact on the environmental quality of sediments of the tidal flat Compared with lakes and seas, tidal flats show frequent seasonal variation in the dynamic processes. If any abnormal weather or waves happen, the deposited pollutants will likely be “discharged”, leading to unpredictable environment hazards. |
| Key words: Tidal mudflat, Heavy metal, Accumulation, Dynamics |
